xref: /linux/drivers/firewire/ohci.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for OHCI 1394 controllers
4  *
5  * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
6  */
7 
8 #include <linux/bitops.h>
9 #include <linux/bug.h>
10 #include <linux/compiler.h>
11 #include <linux/delay.h>
12 #include <linux/device.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/firewire.h>
15 #include <linux/firewire-constants.h>
16 #include <linux/init.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/kernel.h>
20 #include <linux/list.h>
21 #include <linux/mm.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/mutex.h>
25 #include <linux/pci.h>
26 #include <linux/pci_ids.h>
27 #include <linux/slab.h>
28 #include <linux/spinlock.h>
29 #include <linux/string.h>
30 #include <linux/time.h>
31 #include <linux/vmalloc.h>
32 #include <linux/workqueue.h>
33 
34 #include <asm/byteorder.h>
35 #include <asm/page.h>
36 
37 #ifdef CONFIG_PPC_PMAC
38 #include <asm/pmac_feature.h>
39 #endif
40 
41 #include "core.h"
42 #include "ohci.h"
43 #include "packet-header-definitions.h"
44 #include "phy-packet-definitions.h"
45 
46 #include <trace/events/firewire.h>
47 
48 static u32 cond_le32_to_cpu(__le32 value, bool has_be_header_quirk);
49 
50 #define CREATE_TRACE_POINTS
51 #include <trace/events/firewire_ohci.h>
52 
53 #define ohci_notice(ohci, f, args...)	dev_notice(ohci->card.device, f, ##args)
54 #define ohci_err(ohci, f, args...)	dev_err(ohci->card.device, f, ##args)
55 
56 #define DESCRIPTOR_OUTPUT_MORE		0
57 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
58 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
59 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
60 #define DESCRIPTOR_STATUS		(1 << 11)
61 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
62 #define DESCRIPTOR_PING			(1 << 7)
63 #define DESCRIPTOR_YY			(1 << 6)
64 #define DESCRIPTOR_NO_IRQ		(0 << 4)
65 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
66 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
67 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
68 #define DESCRIPTOR_WAIT			(3 << 0)
69 
70 #define DESCRIPTOR_CMD			(0xf << 12)
71 
72 struct descriptor {
73 	__le16 req_count;
74 	__le16 control;
75 	__le32 data_address;
76 	__le32 branch_address;
77 	__le16 res_count;
78 	__le16 transfer_status;
79 } __aligned(16);
80 
81 #define CONTROL_SET(regs)	(regs)
82 #define CONTROL_CLEAR(regs)	((regs) + 4)
83 #define COMMAND_PTR(regs)	((regs) + 12)
84 #define CONTEXT_MATCH(regs)	((regs) + 16)
85 
86 #define AR_BUFFER_SIZE	(32*1024)
87 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
88 /* we need at least two pages for proper list management */
89 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
90 
91 #define MAX_ASYNC_PAYLOAD	4096
92 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
93 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
94 
95 struct ar_context {
96 	struct fw_ohci *ohci;
97 	struct page *pages[AR_BUFFERS];
98 	void *buffer;
99 	struct descriptor *descriptors;
100 	dma_addr_t descriptors_bus;
101 	void *pointer;
102 	unsigned int last_buffer_index;
103 	u32 regs;
104 	struct tasklet_struct tasklet;
105 };
106 
107 struct context;
108 
109 typedef int (*descriptor_callback_t)(struct context *ctx,
110 				     struct descriptor *d,
111 				     struct descriptor *last);
112 
113 /*
114  * A buffer that contains a block of DMA-able coherent memory used for
115  * storing a portion of a DMA descriptor program.
116  */
117 struct descriptor_buffer {
118 	struct list_head list;
119 	dma_addr_t buffer_bus;
120 	size_t buffer_size;
121 	size_t used;
122 	struct descriptor buffer[];
123 };
124 
125 struct context {
126 	struct fw_ohci *ohci;
127 	u32 regs;
128 	int total_allocation;
129 	u32 current_bus;
130 	bool running;
131 	bool flushing;
132 
133 	/*
134 	 * List of page-sized buffers for storing DMA descriptors.
135 	 * Head of list contains buffers in use and tail of list contains
136 	 * free buffers.
137 	 */
138 	struct list_head buffer_list;
139 
140 	/*
141 	 * Pointer to a buffer inside buffer_list that contains the tail
142 	 * end of the current DMA program.
143 	 */
144 	struct descriptor_buffer *buffer_tail;
145 
146 	/*
147 	 * The descriptor containing the branch address of the first
148 	 * descriptor that has not yet been filled by the device.
149 	 */
150 	struct descriptor *last;
151 
152 	/*
153 	 * The last descriptor block in the DMA program. It contains the branch
154 	 * address that must be updated upon appending a new descriptor.
155 	 */
156 	struct descriptor *prev;
157 	int prev_z;
158 
159 	descriptor_callback_t callback;
160 
161 	struct tasklet_struct tasklet;
162 };
163 
164 struct iso_context {
165 	struct fw_iso_context base;
166 	struct context context;
167 	void *header;
168 	size_t header_length;
169 	unsigned long flushing_completions;
170 	u32 mc_buffer_bus;
171 	u16 mc_completed;
172 	u16 last_timestamp;
173 	u8 sync;
174 	u8 tags;
175 };
176 
177 #define CONFIG_ROM_SIZE		(CSR_CONFIG_ROM_END - CSR_CONFIG_ROM)
178 
179 struct fw_ohci {
180 	struct fw_card card;
181 
182 	__iomem char *registers;
183 	int node_id;
184 	int generation;
185 	int request_generation;	/* for timestamping incoming requests */
186 	unsigned quirks;
187 	unsigned int pri_req_max;
188 	u32 bus_time;
189 	bool bus_time_running;
190 	bool is_root;
191 	bool csr_state_setclear_abdicate;
192 	int n_ir;
193 	int n_it;
194 	/*
195 	 * Spinlock for accessing fw_ohci data.  Never call out of
196 	 * this driver with this lock held.
197 	 */
198 	spinlock_t lock;
199 
200 	struct mutex phy_reg_mutex;
201 
202 	void *misc_buffer;
203 	dma_addr_t misc_buffer_bus;
204 
205 	struct ar_context ar_request_ctx;
206 	struct ar_context ar_response_ctx;
207 	struct context at_request_ctx;
208 	struct context at_response_ctx;
209 
210 	u32 it_context_support;
211 	u32 it_context_mask;     /* unoccupied IT contexts */
212 	struct iso_context *it_context_list;
213 	u64 ir_context_channels; /* unoccupied channels */
214 	u32 ir_context_support;
215 	u32 ir_context_mask;     /* unoccupied IR contexts */
216 	struct iso_context *ir_context_list;
217 	u64 mc_channels; /* channels in use by the multichannel IR context */
218 	bool mc_allocated;
219 
220 	__be32    *config_rom;
221 	dma_addr_t config_rom_bus;
222 	__be32    *next_config_rom;
223 	dma_addr_t next_config_rom_bus;
224 	__be32     next_header;
225 
226 	__le32    *self_id;
227 	dma_addr_t self_id_bus;
228 	struct work_struct bus_reset_work;
229 
230 	u32 self_id_buffer[512];
231 };
232 
233 static struct workqueue_struct *selfid_workqueue;
234 
235 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
236 {
237 	return container_of(card, struct fw_ohci, card);
238 }
239 
240 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
241 #define IR_CONTEXT_BUFFER_FILL		0x80000000
242 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
243 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
244 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
245 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
246 
247 #define CONTEXT_RUN	0x8000
248 #define CONTEXT_WAKE	0x1000
249 #define CONTEXT_DEAD	0x0800
250 #define CONTEXT_ACTIVE	0x0400
251 
252 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
253 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
254 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
255 
256 #define OHCI1394_REGISTER_SIZE		0x800
257 #define OHCI1394_PCI_HCI_Control	0x40
258 #define SELF_ID_BUF_SIZE		0x800
259 #define OHCI_VERSION_1_1		0x010010
260 
261 static char ohci_driver_name[] = KBUILD_MODNAME;
262 
263 #define PCI_VENDOR_ID_PINNACLE_SYSTEMS	0x11bd
264 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
265 #define PCI_DEVICE_ID_CREATIVE_SB1394	0x4001
266 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
267 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
268 #define PCI_DEVICE_ID_TI_TSB12LV26	0x8020
269 #define PCI_DEVICE_ID_TI_TSB82AA2	0x8025
270 #define PCI_DEVICE_ID_VIA_VT630X	0x3044
271 #define PCI_REV_ID_VIA_VT6306		0x46
272 #define PCI_DEVICE_ID_VIA_VT6315	0x3403
273 
274 #define QUIRK_CYCLE_TIMER		0x1
275 #define QUIRK_RESET_PACKET		0x2
276 #define QUIRK_BE_HEADERS		0x4
277 #define QUIRK_NO_1394A			0x8
278 #define QUIRK_NO_MSI			0x10
279 #define QUIRK_TI_SLLZ059		0x20
280 #define QUIRK_IR_WAKE			0x40
281 
282 // On PCI Express Root Complex in any type of AMD Ryzen machine, VIA VT6306/6307/6308 with Asmedia
283 // ASM1083/1085 brings an inconvenience that the read accesses to 'Isochronous Cycle Timer' register
284 // (at offset 0xf0 in PCI I/O space) often causes unexpected system reboot. The mechanism is not
285 // clear, since the read access to the other registers is enough safe; e.g. 'Node ID' register,
286 // while it is probable due to detection of any type of PCIe error.
287 #define QUIRK_REBOOT_BY_CYCLE_TIMER_READ	0x80000000
288 
289 #if IS_ENABLED(CONFIG_X86)
290 
291 static bool has_reboot_by_cycle_timer_read_quirk(const struct fw_ohci *ohci)
292 {
293 	return !!(ohci->quirks & QUIRK_REBOOT_BY_CYCLE_TIMER_READ);
294 }
295 
296 #define PCI_DEVICE_ID_ASMEDIA_ASM108X	0x1080
297 
298 static bool detect_vt630x_with_asm1083_on_amd_ryzen_machine(const struct pci_dev *pdev)
299 {
300 	const struct pci_dev *pcie_to_pci_bridge;
301 
302 	// Detect any type of AMD Ryzen machine.
303 	if (!static_cpu_has(X86_FEATURE_ZEN))
304 		return false;
305 
306 	// Detect VIA VT6306/6307/6308.
307 	if (pdev->vendor != PCI_VENDOR_ID_VIA)
308 		return false;
309 	if (pdev->device != PCI_DEVICE_ID_VIA_VT630X)
310 		return false;
311 
312 	// Detect Asmedia ASM1083/1085.
313 	pcie_to_pci_bridge = pdev->bus->self;
314 	if (pcie_to_pci_bridge->vendor != PCI_VENDOR_ID_ASMEDIA)
315 		return false;
316 	if (pcie_to_pci_bridge->device != PCI_DEVICE_ID_ASMEDIA_ASM108X)
317 		return false;
318 
319 	return true;
320 }
321 
322 #else
323 #define has_reboot_by_cycle_timer_read_quirk(ohci) false
324 #define detect_vt630x_with_asm1083_on_amd_ryzen_machine(pdev)	false
325 #endif
326 
327 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
328 static const struct {
329 	unsigned short vendor, device, revision, flags;
330 } ohci_quirks[] = {
331 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
332 		QUIRK_CYCLE_TIMER},
333 
334 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
335 		QUIRK_BE_HEADERS},
336 
337 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
338 		QUIRK_NO_MSI},
339 
340 	{PCI_VENDOR_ID_CREATIVE, PCI_DEVICE_ID_CREATIVE_SB1394, PCI_ANY_ID,
341 		QUIRK_RESET_PACKET},
342 
343 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
344 		QUIRK_NO_MSI},
345 
346 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
347 		QUIRK_CYCLE_TIMER},
348 
349 	{PCI_VENDOR_ID_O2, PCI_ANY_ID, PCI_ANY_ID,
350 		QUIRK_NO_MSI},
351 
352 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
353 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
354 
355 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
356 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
357 
358 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV26, PCI_ANY_ID,
359 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
360 
361 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB82AA2, PCI_ANY_ID,
362 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
363 
364 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
365 		QUIRK_RESET_PACKET},
366 
367 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT630X, PCI_REV_ID_VIA_VT6306,
368 		QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE},
369 
370 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, 0,
371 		QUIRK_CYCLE_TIMER /* FIXME: necessary? */ | QUIRK_NO_MSI},
372 
373 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, PCI_ANY_ID,
374 		QUIRK_NO_MSI},
375 
376 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
377 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
378 };
379 
380 /* This overrides anything that was found in ohci_quirks[]. */
381 static int param_quirks;
382 module_param_named(quirks, param_quirks, int, 0644);
383 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
384 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
385 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
386 	", AR/selfID endianness = "	__stringify(QUIRK_BE_HEADERS)
387 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
388 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
389 	", TI SLLZ059 erratum = "	__stringify(QUIRK_TI_SLLZ059)
390 	", IR wake unreliable = "	__stringify(QUIRK_IR_WAKE)
391 	")");
392 
393 #define OHCI_PARAM_DEBUG_AT_AR		1
394 #define OHCI_PARAM_DEBUG_SELFIDS	2
395 #define OHCI_PARAM_DEBUG_IRQS		4
396 
397 static int param_debug;
398 module_param_named(debug, param_debug, int, 0644);
399 MODULE_PARM_DESC(debug, "Verbose logging, deprecated in v6.11 kernel or later. (default = 0"
400 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
401 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
402 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
403 	", or a combination, or all = -1)");
404 
405 static bool param_remote_dma;
406 module_param_named(remote_dma, param_remote_dma, bool, 0444);
407 MODULE_PARM_DESC(remote_dma, "Enable unfiltered remote DMA (default = N)");
408 
409 static void log_irqs(struct fw_ohci *ohci, u32 evt)
410 {
411 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_IRQS)))
412 		return;
413 
414 	ohci_notice(ohci, "IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
415 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
416 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
417 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
418 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
419 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
420 	    evt & OHCI1394_isochRx		? " IR"			: "",
421 	    evt & OHCI1394_isochTx		? " IT"			: "",
422 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
423 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
424 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
425 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
426 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
427 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
428 	    evt & OHCI1394_busReset		? " busReset"		: "",
429 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
430 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
431 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
432 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
433 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
434 		    OHCI1394_cycleInconsistent |
435 		    OHCI1394_regAccessFail | OHCI1394_busReset)
436 						? " ?"			: "");
437 }
438 
439 static void log_selfids(struct fw_ohci *ohci, int generation, int self_id_count)
440 {
441 	static const char *const speed[] = {
442 		[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
443 	};
444 	static const char *const power[] = {
445 		[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
446 		[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
447 	};
448 	static const char port[] = {
449 		[PHY_PACKET_SELF_ID_PORT_STATUS_NONE] = '.',
450 		[PHY_PACKET_SELF_ID_PORT_STATUS_NCONN] = '-',
451 		[PHY_PACKET_SELF_ID_PORT_STATUS_PARENT] = 'p',
452 		[PHY_PACKET_SELF_ID_PORT_STATUS_CHILD] = 'c',
453 	};
454 	struct self_id_sequence_enumerator enumerator = {
455 		.cursor = ohci->self_id_buffer,
456 		.quadlet_count = self_id_count,
457 	};
458 
459 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
460 		return;
461 
462 	ohci_notice(ohci, "%d selfIDs, generation %d, local node ID %04x\n",
463 		    self_id_count, generation, ohci->node_id);
464 
465 	while (enumerator.quadlet_count > 0) {
466 		unsigned int quadlet_count;
467 		unsigned int port_index;
468 		const u32 *s;
469 		int i;
470 
471 		s = self_id_sequence_enumerator_next(&enumerator, &quadlet_count);
472 		if (IS_ERR(s))
473 			break;
474 
475 		ohci_notice(ohci,
476 		    "selfID 0: %08x, phy %d [%c%c%c] %s gc=%d %s %s%s%s\n",
477 		    *s,
478 		    phy_packet_self_id_get_phy_id(*s),
479 		    port[self_id_sequence_get_port_status(s, quadlet_count, 0)],
480 		    port[self_id_sequence_get_port_status(s, quadlet_count, 1)],
481 		    port[self_id_sequence_get_port_status(s, quadlet_count, 2)],
482 		    speed[*s >> 14 & 3], *s >> 16 & 63,
483 		    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
484 		    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
485 
486 		port_index = 3;
487 		for (i = 1; i < quadlet_count; ++i) {
488 			ohci_notice(ohci,
489 			    "selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
490 			    s[i],
491 			    phy_packet_self_id_get_phy_id(s[i]),
492 			    port[self_id_sequence_get_port_status(s, quadlet_count, port_index)],
493 			    port[self_id_sequence_get_port_status(s, quadlet_count, port_index + 1)],
494 			    port[self_id_sequence_get_port_status(s, quadlet_count, port_index + 2)],
495 			    port[self_id_sequence_get_port_status(s, quadlet_count, port_index + 3)],
496 			    port[self_id_sequence_get_port_status(s, quadlet_count, port_index + 4)],
497 			    port[self_id_sequence_get_port_status(s, quadlet_count, port_index + 5)],
498 			    port[self_id_sequence_get_port_status(s, quadlet_count, port_index + 6)],
499 			    port[self_id_sequence_get_port_status(s, quadlet_count, port_index + 7)]
500 			);
501 
502 			port_index += 8;
503 		}
504 	}
505 }
506 
507 static const char *evts[] = {
508 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
509 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
510 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
511 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
512 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
513 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
514 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
515 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
516 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
517 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
518 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
519 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
520 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
521 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
522 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
523 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
524 	[0x20] = "pending/cancelled",
525 };
526 
527 static void log_ar_at_event(struct fw_ohci *ohci,
528 			    char dir, int speed, u32 *header, int evt)
529 {
530 	static const char *const tcodes[] = {
531 		[TCODE_WRITE_QUADLET_REQUEST]	= "QW req",
532 		[TCODE_WRITE_BLOCK_REQUEST]	= "BW req",
533 		[TCODE_WRITE_RESPONSE]		= "W resp",
534 		[0x3]				= "-reserved-",
535 		[TCODE_READ_QUADLET_REQUEST]	= "QR req",
536 		[TCODE_READ_BLOCK_REQUEST]	= "BR req",
537 		[TCODE_READ_QUADLET_RESPONSE]	= "QR resp",
538 		[TCODE_READ_BLOCK_RESPONSE]	= "BR resp",
539 		[TCODE_CYCLE_START]		= "cycle start",
540 		[TCODE_LOCK_REQUEST]		= "Lk req",
541 		[TCODE_STREAM_DATA]		= "async stream packet",
542 		[TCODE_LOCK_RESPONSE]		= "Lk resp",
543 		[0xc]				= "-reserved-",
544 		[0xd]				= "-reserved-",
545 		[TCODE_LINK_INTERNAL]		= "link internal",
546 		[0xf]				= "-reserved-",
547 	};
548 	int tcode = async_header_get_tcode(header);
549 	char specific[12];
550 
551 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
552 		return;
553 
554 	if (unlikely(evt >= ARRAY_SIZE(evts)))
555 		evt = 0x1f;
556 
557 	if (evt == OHCI1394_evt_bus_reset) {
558 		ohci_notice(ohci, "A%c evt_bus_reset, generation %d\n",
559 			    dir, (header[2] >> 16) & 0xff);
560 		return;
561 	}
562 
563 	switch (tcode) {
564 	case TCODE_WRITE_QUADLET_REQUEST:
565 	case TCODE_READ_QUADLET_RESPONSE:
566 	case TCODE_CYCLE_START:
567 		snprintf(specific, sizeof(specific), " = %08x",
568 			 be32_to_cpu((__force __be32)header[3]));
569 		break;
570 	case TCODE_WRITE_BLOCK_REQUEST:
571 	case TCODE_READ_BLOCK_REQUEST:
572 	case TCODE_READ_BLOCK_RESPONSE:
573 	case TCODE_LOCK_REQUEST:
574 	case TCODE_LOCK_RESPONSE:
575 		snprintf(specific, sizeof(specific), " %x,%x",
576 			 async_header_get_data_length(header),
577 			 async_header_get_extended_tcode(header));
578 		break;
579 	default:
580 		specific[0] = '\0';
581 	}
582 
583 	switch (tcode) {
584 	case TCODE_STREAM_DATA:
585 		ohci_notice(ohci, "A%c %s, %s\n",
586 			    dir, evts[evt], tcodes[tcode]);
587 		break;
588 	case TCODE_LINK_INTERNAL:
589 		ohci_notice(ohci, "A%c %s, PHY %08x %08x\n",
590 			    dir, evts[evt], header[1], header[2]);
591 		break;
592 	case TCODE_WRITE_QUADLET_REQUEST:
593 	case TCODE_WRITE_BLOCK_REQUEST:
594 	case TCODE_READ_QUADLET_REQUEST:
595 	case TCODE_READ_BLOCK_REQUEST:
596 	case TCODE_LOCK_REQUEST:
597 		ohci_notice(ohci,
598 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s, %012llx%s\n",
599 			    dir, speed, async_header_get_tlabel(header),
600 			    async_header_get_source(header), async_header_get_destination(header),
601 			    evts[evt], tcodes[tcode], async_header_get_offset(header), specific);
602 		break;
603 	default:
604 		ohci_notice(ohci,
605 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s%s\n",
606 			    dir, speed, async_header_get_tlabel(header),
607 			    async_header_get_source(header), async_header_get_destination(header),
608 			    evts[evt], tcodes[tcode], specific);
609 	}
610 }
611 
612 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
613 {
614 	writel(data, ohci->registers + offset);
615 }
616 
617 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
618 {
619 	return readl(ohci->registers + offset);
620 }
621 
622 static inline void flush_writes(const struct fw_ohci *ohci)
623 {
624 	/* Do a dummy read to flush writes. */
625 	reg_read(ohci, OHCI1394_Version);
626 }
627 
628 /*
629  * Beware!  read_phy_reg(), write_phy_reg(), update_phy_reg(), and
630  * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
631  * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
632  * directly.  Exceptions are intrinsically serialized contexts like pci_probe.
633  */
634 static int read_phy_reg(struct fw_ohci *ohci, int addr)
635 {
636 	u32 val;
637 	int i;
638 
639 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
640 	for (i = 0; i < 3 + 100; i++) {
641 		val = reg_read(ohci, OHCI1394_PhyControl);
642 		if (!~val)
643 			return -ENODEV; /* Card was ejected. */
644 
645 		if (val & OHCI1394_PhyControl_ReadDone)
646 			return OHCI1394_PhyControl_ReadData(val);
647 
648 		/*
649 		 * Try a few times without waiting.  Sleeping is necessary
650 		 * only when the link/PHY interface is busy.
651 		 */
652 		if (i >= 3)
653 			msleep(1);
654 	}
655 	ohci_err(ohci, "failed to read phy reg %d\n", addr);
656 	dump_stack();
657 
658 	return -EBUSY;
659 }
660 
661 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
662 {
663 	int i;
664 
665 	reg_write(ohci, OHCI1394_PhyControl,
666 		  OHCI1394_PhyControl_Write(addr, val));
667 	for (i = 0; i < 3 + 100; i++) {
668 		val = reg_read(ohci, OHCI1394_PhyControl);
669 		if (!~val)
670 			return -ENODEV; /* Card was ejected. */
671 
672 		if (!(val & OHCI1394_PhyControl_WritePending))
673 			return 0;
674 
675 		if (i >= 3)
676 			msleep(1);
677 	}
678 	ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
679 	dump_stack();
680 
681 	return -EBUSY;
682 }
683 
684 static int update_phy_reg(struct fw_ohci *ohci, int addr,
685 			  int clear_bits, int set_bits)
686 {
687 	int ret = read_phy_reg(ohci, addr);
688 	if (ret < 0)
689 		return ret;
690 
691 	/*
692 	 * The interrupt status bits are cleared by writing a one bit.
693 	 * Avoid clearing them unless explicitly requested in set_bits.
694 	 */
695 	if (addr == 5)
696 		clear_bits |= PHY_INT_STATUS_BITS;
697 
698 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
699 }
700 
701 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
702 {
703 	int ret;
704 
705 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
706 	if (ret < 0)
707 		return ret;
708 
709 	return read_phy_reg(ohci, addr);
710 }
711 
712 static int ohci_read_phy_reg(struct fw_card *card, int addr)
713 {
714 	struct fw_ohci *ohci = fw_ohci(card);
715 
716 	guard(mutex)(&ohci->phy_reg_mutex);
717 
718 	return read_phy_reg(ohci, addr);
719 }
720 
721 static int ohci_update_phy_reg(struct fw_card *card, int addr,
722 			       int clear_bits, int set_bits)
723 {
724 	struct fw_ohci *ohci = fw_ohci(card);
725 
726 	guard(mutex)(&ohci->phy_reg_mutex);
727 
728 	return update_phy_reg(ohci, addr, clear_bits, set_bits);
729 }
730 
731 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
732 {
733 	return page_private(ctx->pages[i]);
734 }
735 
736 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
737 {
738 	struct descriptor *d;
739 
740 	d = &ctx->descriptors[index];
741 	d->branch_address  &= cpu_to_le32(~0xf);
742 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
743 	d->transfer_status =  0;
744 
745 	wmb(); /* finish init of new descriptors before branch_address update */
746 	d = &ctx->descriptors[ctx->last_buffer_index];
747 	d->branch_address  |= cpu_to_le32(1);
748 
749 	ctx->last_buffer_index = index;
750 
751 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
752 }
753 
754 static void ar_context_release(struct ar_context *ctx)
755 {
756 	struct device *dev = ctx->ohci->card.device;
757 	unsigned int i;
758 
759 	if (!ctx->buffer)
760 		return;
761 
762 	vunmap(ctx->buffer);
763 
764 	for (i = 0; i < AR_BUFFERS; i++) {
765 		if (ctx->pages[i])
766 			dma_free_pages(dev, PAGE_SIZE, ctx->pages[i],
767 				       ar_buffer_bus(ctx, i), DMA_FROM_DEVICE);
768 	}
769 }
770 
771 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
772 {
773 	struct fw_ohci *ohci = ctx->ohci;
774 
775 	if (reg_read(ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
776 		reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
777 		flush_writes(ohci);
778 
779 		ohci_err(ohci, "AR error: %s; DMA stopped\n", error_msg);
780 	}
781 	/* FIXME: restart? */
782 }
783 
784 static inline unsigned int ar_next_buffer_index(unsigned int index)
785 {
786 	return (index + 1) % AR_BUFFERS;
787 }
788 
789 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
790 {
791 	return ar_next_buffer_index(ctx->last_buffer_index);
792 }
793 
794 /*
795  * We search for the buffer that contains the last AR packet DMA data written
796  * by the controller.
797  */
798 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
799 						 unsigned int *buffer_offset)
800 {
801 	unsigned int i, next_i, last = ctx->last_buffer_index;
802 	__le16 res_count, next_res_count;
803 
804 	i = ar_first_buffer_index(ctx);
805 	res_count = READ_ONCE(ctx->descriptors[i].res_count);
806 
807 	/* A buffer that is not yet completely filled must be the last one. */
808 	while (i != last && res_count == 0) {
809 
810 		/* Peek at the next descriptor. */
811 		next_i = ar_next_buffer_index(i);
812 		rmb(); /* read descriptors in order */
813 		next_res_count = READ_ONCE(ctx->descriptors[next_i].res_count);
814 		/*
815 		 * If the next descriptor is still empty, we must stop at this
816 		 * descriptor.
817 		 */
818 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
819 			/*
820 			 * The exception is when the DMA data for one packet is
821 			 * split over three buffers; in this case, the middle
822 			 * buffer's descriptor might be never updated by the
823 			 * controller and look still empty, and we have to peek
824 			 * at the third one.
825 			 */
826 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
827 				next_i = ar_next_buffer_index(next_i);
828 				rmb();
829 				next_res_count = READ_ONCE(ctx->descriptors[next_i].res_count);
830 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
831 					goto next_buffer_is_active;
832 			}
833 
834 			break;
835 		}
836 
837 next_buffer_is_active:
838 		i = next_i;
839 		res_count = next_res_count;
840 	}
841 
842 	rmb(); /* read res_count before the DMA data */
843 
844 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
845 	if (*buffer_offset > PAGE_SIZE) {
846 		*buffer_offset = 0;
847 		ar_context_abort(ctx, "corrupted descriptor");
848 	}
849 
850 	return i;
851 }
852 
853 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
854 				    unsigned int end_buffer_index,
855 				    unsigned int end_buffer_offset)
856 {
857 	unsigned int i;
858 
859 	i = ar_first_buffer_index(ctx);
860 	while (i != end_buffer_index) {
861 		dma_sync_single_for_cpu(ctx->ohci->card.device,
862 					ar_buffer_bus(ctx, i),
863 					PAGE_SIZE, DMA_FROM_DEVICE);
864 		i = ar_next_buffer_index(i);
865 	}
866 	if (end_buffer_offset > 0)
867 		dma_sync_single_for_cpu(ctx->ohci->card.device,
868 					ar_buffer_bus(ctx, i),
869 					end_buffer_offset, DMA_FROM_DEVICE);
870 }
871 
872 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
873 static u32 cond_le32_to_cpu(__le32 value, bool has_be_header_quirk)
874 {
875 	return has_be_header_quirk ? (__force __u32)value : le32_to_cpu(value);
876 }
877 
878 static bool has_be_header_quirk(const struct fw_ohci *ohci)
879 {
880 	return !!(ohci->quirks & QUIRK_BE_HEADERS);
881 }
882 #else
883 static u32 cond_le32_to_cpu(__le32 value, bool has_be_header_quirk __maybe_unused)
884 {
885 	return le32_to_cpu(value);
886 }
887 
888 static bool has_be_header_quirk(const struct fw_ohci *ohci)
889 {
890 	return false;
891 }
892 #endif
893 
894 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
895 {
896 	struct fw_ohci *ohci = ctx->ohci;
897 	struct fw_packet p;
898 	u32 status, length, tcode;
899 	int evt;
900 
901 	p.header[0] = cond_le32_to_cpu(buffer[0], has_be_header_quirk(ohci));
902 	p.header[1] = cond_le32_to_cpu(buffer[1], has_be_header_quirk(ohci));
903 	p.header[2] = cond_le32_to_cpu(buffer[2], has_be_header_quirk(ohci));
904 
905 	tcode = async_header_get_tcode(p.header);
906 	switch (tcode) {
907 	case TCODE_WRITE_QUADLET_REQUEST:
908 	case TCODE_READ_QUADLET_RESPONSE:
909 		p.header[3] = (__force __u32) buffer[3];
910 		p.header_length = 16;
911 		p.payload_length = 0;
912 		break;
913 
914 	case TCODE_READ_BLOCK_REQUEST :
915 		p.header[3] = cond_le32_to_cpu(buffer[3], has_be_header_quirk(ohci));
916 		p.header_length = 16;
917 		p.payload_length = 0;
918 		break;
919 
920 	case TCODE_WRITE_BLOCK_REQUEST:
921 	case TCODE_READ_BLOCK_RESPONSE:
922 	case TCODE_LOCK_REQUEST:
923 	case TCODE_LOCK_RESPONSE:
924 		p.header[3] = cond_le32_to_cpu(buffer[3], has_be_header_quirk(ohci));
925 		p.header_length = 16;
926 		p.payload_length = async_header_get_data_length(p.header);
927 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
928 			ar_context_abort(ctx, "invalid packet length");
929 			return NULL;
930 		}
931 		break;
932 
933 	case TCODE_WRITE_RESPONSE:
934 	case TCODE_READ_QUADLET_REQUEST:
935 	case TCODE_LINK_INTERNAL:
936 		p.header_length = 12;
937 		p.payload_length = 0;
938 		break;
939 
940 	default:
941 		ar_context_abort(ctx, "invalid tcode");
942 		return NULL;
943 	}
944 
945 	p.payload = (void *) buffer + p.header_length;
946 
947 	/* FIXME: What to do about evt_* errors? */
948 	length = (p.header_length + p.payload_length + 3) / 4;
949 	status = cond_le32_to_cpu(buffer[length], has_be_header_quirk(ohci));
950 	evt    = (status >> 16) & 0x1f;
951 
952 	p.ack        = evt - 16;
953 	p.speed      = (status >> 21) & 0x7;
954 	p.timestamp  = status & 0xffff;
955 	p.generation = ohci->request_generation;
956 
957 	log_ar_at_event(ohci, 'R', p.speed, p.header, evt);
958 
959 	/*
960 	 * Several controllers, notably from NEC and VIA, forget to
961 	 * write ack_complete status at PHY packet reception.
962 	 */
963 	if (evt == OHCI1394_evt_no_status && tcode == TCODE_LINK_INTERNAL)
964 		p.ack = ACK_COMPLETE;
965 
966 	/*
967 	 * The OHCI bus reset handler synthesizes a PHY packet with
968 	 * the new generation number when a bus reset happens (see
969 	 * section 8.4.2.3).  This helps us determine when a request
970 	 * was received and make sure we send the response in the same
971 	 * generation.  We only need this for requests; for responses
972 	 * we use the unique tlabel for finding the matching
973 	 * request.
974 	 *
975 	 * Alas some chips sometimes emit bus reset packets with a
976 	 * wrong generation.  We set the correct generation for these
977 	 * at a slightly incorrect time (in bus_reset_work).
978 	 */
979 	if (evt == OHCI1394_evt_bus_reset) {
980 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
981 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
982 	} else if (ctx == &ohci->ar_request_ctx) {
983 		fw_core_handle_request(&ohci->card, &p);
984 	} else {
985 		fw_core_handle_response(&ohci->card, &p);
986 	}
987 
988 	return buffer + length + 1;
989 }
990 
991 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
992 {
993 	void *next;
994 
995 	while (p < end) {
996 		next = handle_ar_packet(ctx, p);
997 		if (!next)
998 			return p;
999 		p = next;
1000 	}
1001 
1002 	return p;
1003 }
1004 
1005 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
1006 {
1007 	unsigned int i;
1008 
1009 	i = ar_first_buffer_index(ctx);
1010 	while (i != end_buffer) {
1011 		dma_sync_single_for_device(ctx->ohci->card.device,
1012 					   ar_buffer_bus(ctx, i),
1013 					   PAGE_SIZE, DMA_FROM_DEVICE);
1014 		ar_context_link_page(ctx, i);
1015 		i = ar_next_buffer_index(i);
1016 	}
1017 }
1018 
1019 static void ar_context_tasklet(unsigned long data)
1020 {
1021 	struct ar_context *ctx = (struct ar_context *)data;
1022 	unsigned int end_buffer_index, end_buffer_offset;
1023 	void *p, *end;
1024 
1025 	p = ctx->pointer;
1026 	if (!p)
1027 		return;
1028 
1029 	end_buffer_index = ar_search_last_active_buffer(ctx,
1030 							&end_buffer_offset);
1031 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
1032 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
1033 
1034 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
1035 		/*
1036 		 * The filled part of the overall buffer wraps around; handle
1037 		 * all packets up to the buffer end here.  If the last packet
1038 		 * wraps around, its tail will be visible after the buffer end
1039 		 * because the buffer start pages are mapped there again.
1040 		 */
1041 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
1042 		p = handle_ar_packets(ctx, p, buffer_end);
1043 		if (p < buffer_end)
1044 			goto error;
1045 		/* adjust p to point back into the actual buffer */
1046 		p -= AR_BUFFERS * PAGE_SIZE;
1047 	}
1048 
1049 	p = handle_ar_packets(ctx, p, end);
1050 	if (p != end) {
1051 		if (p > end)
1052 			ar_context_abort(ctx, "inconsistent descriptor");
1053 		goto error;
1054 	}
1055 
1056 	ctx->pointer = p;
1057 	ar_recycle_buffers(ctx, end_buffer_index);
1058 
1059 	return;
1060 
1061 error:
1062 	ctx->pointer = NULL;
1063 }
1064 
1065 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
1066 			   unsigned int descriptors_offset, u32 regs)
1067 {
1068 	struct device *dev = ohci->card.device;
1069 	unsigned int i;
1070 	dma_addr_t dma_addr;
1071 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
1072 	struct descriptor *d;
1073 
1074 	ctx->regs        = regs;
1075 	ctx->ohci        = ohci;
1076 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
1077 
1078 	for (i = 0; i < AR_BUFFERS; i++) {
1079 		ctx->pages[i] = dma_alloc_pages(dev, PAGE_SIZE, &dma_addr,
1080 						DMA_FROM_DEVICE, GFP_KERNEL);
1081 		if (!ctx->pages[i])
1082 			goto out_of_memory;
1083 		set_page_private(ctx->pages[i], dma_addr);
1084 		dma_sync_single_for_device(dev, dma_addr, PAGE_SIZE,
1085 					   DMA_FROM_DEVICE);
1086 	}
1087 
1088 	for (i = 0; i < AR_BUFFERS; i++)
1089 		pages[i]              = ctx->pages[i];
1090 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
1091 		pages[AR_BUFFERS + i] = ctx->pages[i];
1092 	ctx->buffer = vmap(pages, ARRAY_SIZE(pages), VM_MAP, PAGE_KERNEL);
1093 	if (!ctx->buffer)
1094 		goto out_of_memory;
1095 
1096 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
1097 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
1098 
1099 	for (i = 0; i < AR_BUFFERS; i++) {
1100 		d = &ctx->descriptors[i];
1101 		d->req_count      = cpu_to_le16(PAGE_SIZE);
1102 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
1103 						DESCRIPTOR_STATUS |
1104 						DESCRIPTOR_BRANCH_ALWAYS);
1105 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
1106 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
1107 			ar_next_buffer_index(i) * sizeof(struct descriptor));
1108 	}
1109 
1110 	return 0;
1111 
1112 out_of_memory:
1113 	ar_context_release(ctx);
1114 
1115 	return -ENOMEM;
1116 }
1117 
1118 static void ar_context_run(struct ar_context *ctx)
1119 {
1120 	unsigned int i;
1121 
1122 	for (i = 0; i < AR_BUFFERS; i++)
1123 		ar_context_link_page(ctx, i);
1124 
1125 	ctx->pointer = ctx->buffer;
1126 
1127 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1128 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1129 }
1130 
1131 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1132 {
1133 	__le16 branch;
1134 
1135 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1136 
1137 	/* figure out which descriptor the branch address goes in */
1138 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1139 		return d;
1140 	else
1141 		return d + z - 1;
1142 }
1143 
1144 static void context_retire_descriptors(struct context *ctx)
1145 {
1146 	struct descriptor *d, *last;
1147 	u32 address;
1148 	int z;
1149 	struct descriptor_buffer *desc;
1150 
1151 	desc = list_entry(ctx->buffer_list.next,
1152 			struct descriptor_buffer, list);
1153 	last = ctx->last;
1154 	while (last->branch_address != 0) {
1155 		struct descriptor_buffer *old_desc = desc;
1156 		address = le32_to_cpu(last->branch_address);
1157 		z = address & 0xf;
1158 		address &= ~0xf;
1159 		ctx->current_bus = address;
1160 
1161 		/* If the branch address points to a buffer outside of the
1162 		 * current buffer, advance to the next buffer. */
1163 		if (address < desc->buffer_bus ||
1164 				address >= desc->buffer_bus + desc->used)
1165 			desc = list_entry(desc->list.next,
1166 					struct descriptor_buffer, list);
1167 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1168 		last = find_branch_descriptor(d, z);
1169 
1170 		if (!ctx->callback(ctx, d, last))
1171 			break;
1172 
1173 		if (old_desc != desc) {
1174 			// If we've advanced to the next buffer, move the previous buffer to the
1175 			// free list.
1176 			old_desc->used = 0;
1177 			guard(spinlock_irqsave)(&ctx->ohci->lock);
1178 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1179 		}
1180 		ctx->last = last;
1181 	}
1182 }
1183 
1184 static void context_tasklet(unsigned long data)
1185 {
1186 	struct context *ctx = (struct context *) data;
1187 
1188 	context_retire_descriptors(ctx);
1189 }
1190 
1191 static void ohci_isoc_context_work(struct work_struct *work)
1192 {
1193 	struct fw_iso_context *base = container_of(work, struct fw_iso_context, work);
1194 	struct iso_context *isoc_ctx = container_of(base, struct iso_context, base);
1195 
1196 	context_retire_descriptors(&isoc_ctx->context);
1197 }
1198 
1199 /*
1200  * Allocate a new buffer and add it to the list of free buffers for this
1201  * context.  Must be called with ohci->lock held.
1202  */
1203 static int context_add_buffer(struct context *ctx)
1204 {
1205 	struct descriptor_buffer *desc;
1206 	dma_addr_t bus_addr;
1207 	int offset;
1208 
1209 	/*
1210 	 * 16MB of descriptors should be far more than enough for any DMA
1211 	 * program.  This will catch run-away userspace or DoS attacks.
1212 	 */
1213 	if (ctx->total_allocation >= 16*1024*1024)
1214 		return -ENOMEM;
1215 
1216 	desc = dmam_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE, &bus_addr, GFP_ATOMIC);
1217 	if (!desc)
1218 		return -ENOMEM;
1219 
1220 	offset = (void *)&desc->buffer - (void *)desc;
1221 	/*
1222 	 * Some controllers, like JMicron ones, always issue 0x20-byte DMA reads
1223 	 * for descriptors, even 0x10-byte ones. This can cause page faults when
1224 	 * an IOMMU is in use and the oversized read crosses a page boundary.
1225 	 * Work around this by always leaving at least 0x10 bytes of padding.
1226 	 */
1227 	desc->buffer_size = PAGE_SIZE - offset - 0x10;
1228 	desc->buffer_bus = bus_addr + offset;
1229 	desc->used = 0;
1230 
1231 	list_add_tail(&desc->list, &ctx->buffer_list);
1232 	ctx->total_allocation += PAGE_SIZE;
1233 
1234 	return 0;
1235 }
1236 
1237 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1238 			u32 regs, descriptor_callback_t callback)
1239 {
1240 	ctx->ohci = ohci;
1241 	ctx->regs = regs;
1242 	ctx->total_allocation = 0;
1243 
1244 	INIT_LIST_HEAD(&ctx->buffer_list);
1245 	if (context_add_buffer(ctx) < 0)
1246 		return -ENOMEM;
1247 
1248 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1249 			struct descriptor_buffer, list);
1250 
1251 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1252 	ctx->callback = callback;
1253 
1254 	/*
1255 	 * We put a dummy descriptor in the buffer that has a NULL
1256 	 * branch address and looks like it's been sent.  That way we
1257 	 * have a descriptor to append DMA programs to.
1258 	 */
1259 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1260 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1261 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1262 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1263 	ctx->last = ctx->buffer_tail->buffer;
1264 	ctx->prev = ctx->buffer_tail->buffer;
1265 	ctx->prev_z = 1;
1266 
1267 	return 0;
1268 }
1269 
1270 static void context_release(struct context *ctx)
1271 {
1272 	struct fw_card *card = &ctx->ohci->card;
1273 	struct descriptor_buffer *desc, *tmp;
1274 
1275 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list) {
1276 		dmam_free_coherent(card->device, PAGE_SIZE, desc,
1277 				   desc->buffer_bus - ((void *)&desc->buffer - (void *)desc));
1278 	}
1279 }
1280 
1281 /* Must be called with ohci->lock held */
1282 static struct descriptor *context_get_descriptors(struct context *ctx,
1283 						  int z, dma_addr_t *d_bus)
1284 {
1285 	struct descriptor *d = NULL;
1286 	struct descriptor_buffer *desc = ctx->buffer_tail;
1287 
1288 	if (z * sizeof(*d) > desc->buffer_size)
1289 		return NULL;
1290 
1291 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1292 		/* No room for the descriptor in this buffer, so advance to the
1293 		 * next one. */
1294 
1295 		if (desc->list.next == &ctx->buffer_list) {
1296 			/* If there is no free buffer next in the list,
1297 			 * allocate one. */
1298 			if (context_add_buffer(ctx) < 0)
1299 				return NULL;
1300 		}
1301 		desc = list_entry(desc->list.next,
1302 				struct descriptor_buffer, list);
1303 		ctx->buffer_tail = desc;
1304 	}
1305 
1306 	d = desc->buffer + desc->used / sizeof(*d);
1307 	memset(d, 0, z * sizeof(*d));
1308 	*d_bus = desc->buffer_bus + desc->used;
1309 
1310 	return d;
1311 }
1312 
1313 static void context_run(struct context *ctx, u32 extra)
1314 {
1315 	struct fw_ohci *ohci = ctx->ohci;
1316 
1317 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1318 		  le32_to_cpu(ctx->last->branch_address));
1319 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1320 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1321 	ctx->running = true;
1322 	flush_writes(ohci);
1323 }
1324 
1325 static void context_append(struct context *ctx,
1326 			   struct descriptor *d, int z, int extra)
1327 {
1328 	dma_addr_t d_bus;
1329 	struct descriptor_buffer *desc = ctx->buffer_tail;
1330 	struct descriptor *d_branch;
1331 
1332 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1333 
1334 	desc->used += (z + extra) * sizeof(*d);
1335 
1336 	wmb(); /* finish init of new descriptors before branch_address update */
1337 
1338 	d_branch = find_branch_descriptor(ctx->prev, ctx->prev_z);
1339 	d_branch->branch_address = cpu_to_le32(d_bus | z);
1340 
1341 	/*
1342 	 * VT6306 incorrectly checks only the single descriptor at the
1343 	 * CommandPtr when the wake bit is written, so if it's a
1344 	 * multi-descriptor block starting with an INPUT_MORE, put a copy of
1345 	 * the branch address in the first descriptor.
1346 	 *
1347 	 * Not doing this for transmit contexts since not sure how it interacts
1348 	 * with skip addresses.
1349 	 */
1350 	if (unlikely(ctx->ohci->quirks & QUIRK_IR_WAKE) &&
1351 	    d_branch != ctx->prev &&
1352 	    (ctx->prev->control & cpu_to_le16(DESCRIPTOR_CMD)) ==
1353 	     cpu_to_le16(DESCRIPTOR_INPUT_MORE)) {
1354 		ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1355 	}
1356 
1357 	ctx->prev = d;
1358 	ctx->prev_z = z;
1359 }
1360 
1361 static void context_stop(struct context *ctx)
1362 {
1363 	struct fw_ohci *ohci = ctx->ohci;
1364 	u32 reg;
1365 	int i;
1366 
1367 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1368 	ctx->running = false;
1369 
1370 	for (i = 0; i < 1000; i++) {
1371 		reg = reg_read(ohci, CONTROL_SET(ctx->regs));
1372 		if ((reg & CONTEXT_ACTIVE) == 0)
1373 			return;
1374 
1375 		if (i)
1376 			udelay(10);
1377 	}
1378 	ohci_err(ohci, "DMA context still active (0x%08x)\n", reg);
1379 }
1380 
1381 struct driver_data {
1382 	u8 inline_data[8];
1383 	struct fw_packet *packet;
1384 };
1385 
1386 /*
1387  * This function apppends a packet to the DMA queue for transmission.
1388  * Must always be called with the ochi->lock held to ensure proper
1389  * generation handling and locking around packet queue manipulation.
1390  */
1391 static int at_context_queue_packet(struct context *ctx,
1392 				   struct fw_packet *packet)
1393 {
1394 	struct fw_ohci *ohci = ctx->ohci;
1395 	dma_addr_t d_bus, payload_bus;
1396 	struct driver_data *driver_data;
1397 	struct descriptor *d, *last;
1398 	__le32 *header;
1399 	int z, tcode;
1400 
1401 	d = context_get_descriptors(ctx, 4, &d_bus);
1402 	if (d == NULL) {
1403 		packet->ack = RCODE_SEND_ERROR;
1404 		return -1;
1405 	}
1406 
1407 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1408 	d[0].res_count = cpu_to_le16(packet->timestamp);
1409 
1410 	tcode = async_header_get_tcode(packet->header);
1411 	header = (__le32 *) &d[1];
1412 	switch (tcode) {
1413 	case TCODE_WRITE_QUADLET_REQUEST:
1414 	case TCODE_WRITE_BLOCK_REQUEST:
1415 	case TCODE_WRITE_RESPONSE:
1416 	case TCODE_READ_QUADLET_REQUEST:
1417 	case TCODE_READ_BLOCK_REQUEST:
1418 	case TCODE_READ_QUADLET_RESPONSE:
1419 	case TCODE_READ_BLOCK_RESPONSE:
1420 	case TCODE_LOCK_REQUEST:
1421 	case TCODE_LOCK_RESPONSE:
1422 		ohci1394_at_data_set_src_bus_id(header, false);
1423 		ohci1394_at_data_set_speed(header, packet->speed);
1424 		ohci1394_at_data_set_tlabel(header, async_header_get_tlabel(packet->header));
1425 		ohci1394_at_data_set_retry(header, async_header_get_retry(packet->header));
1426 		ohci1394_at_data_set_tcode(header, tcode);
1427 
1428 		ohci1394_at_data_set_destination_id(header,
1429 						    async_header_get_destination(packet->header));
1430 
1431 		if (ctx == &ctx->ohci->at_response_ctx) {
1432 			ohci1394_at_data_set_rcode(header, async_header_get_rcode(packet->header));
1433 		} else {
1434 			ohci1394_at_data_set_destination_offset(header,
1435 							async_header_get_offset(packet->header));
1436 		}
1437 
1438 		if (tcode_is_block_packet(tcode))
1439 			header[3] = cpu_to_le32(packet->header[3]);
1440 		else
1441 			header[3] = (__force __le32) packet->header[3];
1442 
1443 		d[0].req_count = cpu_to_le16(packet->header_length);
1444 		break;
1445 	case TCODE_LINK_INTERNAL:
1446 		ohci1394_at_data_set_speed(header, packet->speed);
1447 		ohci1394_at_data_set_tcode(header, TCODE_LINK_INTERNAL);
1448 
1449 		header[1] = cpu_to_le32(packet->header[1]);
1450 		header[2] = cpu_to_le32(packet->header[2]);
1451 		d[0].req_count = cpu_to_le16(12);
1452 
1453 		if (is_ping_packet(&packet->header[1]))
1454 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1455 		break;
1456 
1457 	case TCODE_STREAM_DATA:
1458 		ohci1394_it_data_set_speed(header, packet->speed);
1459 		ohci1394_it_data_set_tag(header, isoc_header_get_tag(packet->header[0]));
1460 		ohci1394_it_data_set_channel(header, isoc_header_get_channel(packet->header[0]));
1461 		ohci1394_it_data_set_tcode(header, TCODE_STREAM_DATA);
1462 		ohci1394_it_data_set_sync(header, isoc_header_get_sy(packet->header[0]));
1463 
1464 		ohci1394_it_data_set_data_length(header, isoc_header_get_data_length(packet->header[0]));
1465 
1466 		d[0].req_count = cpu_to_le16(8);
1467 		break;
1468 
1469 	default:
1470 		/* BUG(); */
1471 		packet->ack = RCODE_SEND_ERROR;
1472 		return -1;
1473 	}
1474 
1475 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1476 	driver_data = (struct driver_data *) &d[3];
1477 	driver_data->packet = packet;
1478 	packet->driver_data = driver_data;
1479 
1480 	if (packet->payload_length > 0) {
1481 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1482 			payload_bus = dma_map_single(ohci->card.device,
1483 						     packet->payload,
1484 						     packet->payload_length,
1485 						     DMA_TO_DEVICE);
1486 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1487 				packet->ack = RCODE_SEND_ERROR;
1488 				return -1;
1489 			}
1490 			packet->payload_bus	= payload_bus;
1491 			packet->payload_mapped	= true;
1492 		} else {
1493 			memcpy(driver_data->inline_data, packet->payload,
1494 			       packet->payload_length);
1495 			payload_bus = d_bus + 3 * sizeof(*d);
1496 		}
1497 
1498 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1499 		d[2].data_address = cpu_to_le32(payload_bus);
1500 		last = &d[2];
1501 		z = 3;
1502 	} else {
1503 		last = &d[0];
1504 		z = 2;
1505 	}
1506 
1507 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1508 				     DESCRIPTOR_IRQ_ALWAYS |
1509 				     DESCRIPTOR_BRANCH_ALWAYS);
1510 
1511 	/* FIXME: Document how the locking works. */
1512 	if (ohci->generation != packet->generation) {
1513 		if (packet->payload_mapped)
1514 			dma_unmap_single(ohci->card.device, payload_bus,
1515 					 packet->payload_length, DMA_TO_DEVICE);
1516 		packet->ack = RCODE_GENERATION;
1517 		return -1;
1518 	}
1519 
1520 	context_append(ctx, d, z, 4 - z);
1521 
1522 	if (ctx->running)
1523 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1524 	else
1525 		context_run(ctx, 0);
1526 
1527 	return 0;
1528 }
1529 
1530 static void at_context_flush(struct context *ctx)
1531 {
1532 	tasklet_disable(&ctx->tasklet);
1533 
1534 	ctx->flushing = true;
1535 	context_tasklet((unsigned long)ctx);
1536 	ctx->flushing = false;
1537 
1538 	tasklet_enable(&ctx->tasklet);
1539 }
1540 
1541 static int handle_at_packet(struct context *context,
1542 			    struct descriptor *d,
1543 			    struct descriptor *last)
1544 {
1545 	struct driver_data *driver_data;
1546 	struct fw_packet *packet;
1547 	struct fw_ohci *ohci = context->ohci;
1548 	int evt;
1549 
1550 	if (last->transfer_status == 0 && !context->flushing)
1551 		/* This descriptor isn't done yet, stop iteration. */
1552 		return 0;
1553 
1554 	driver_data = (struct driver_data *) &d[3];
1555 	packet = driver_data->packet;
1556 	if (packet == NULL)
1557 		/* This packet was cancelled, just continue. */
1558 		return 1;
1559 
1560 	if (packet->payload_mapped)
1561 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1562 				 packet->payload_length, DMA_TO_DEVICE);
1563 
1564 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1565 	packet->timestamp = le16_to_cpu(last->res_count);
1566 
1567 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, evt);
1568 
1569 	switch (evt) {
1570 	case OHCI1394_evt_timeout:
1571 		/* Async response transmit timed out. */
1572 		packet->ack = RCODE_CANCELLED;
1573 		break;
1574 
1575 	case OHCI1394_evt_flushed:
1576 		/*
1577 		 * The packet was flushed should give same error as
1578 		 * when we try to use a stale generation count.
1579 		 */
1580 		packet->ack = RCODE_GENERATION;
1581 		break;
1582 
1583 	case OHCI1394_evt_missing_ack:
1584 		if (context->flushing)
1585 			packet->ack = RCODE_GENERATION;
1586 		else {
1587 			/*
1588 			 * Using a valid (current) generation count, but the
1589 			 * node is not on the bus or not sending acks.
1590 			 */
1591 			packet->ack = RCODE_NO_ACK;
1592 		}
1593 		break;
1594 
1595 	case ACK_COMPLETE + 0x10:
1596 	case ACK_PENDING + 0x10:
1597 	case ACK_BUSY_X + 0x10:
1598 	case ACK_BUSY_A + 0x10:
1599 	case ACK_BUSY_B + 0x10:
1600 	case ACK_DATA_ERROR + 0x10:
1601 	case ACK_TYPE_ERROR + 0x10:
1602 		packet->ack = evt - 0x10;
1603 		break;
1604 
1605 	case OHCI1394_evt_no_status:
1606 		if (context->flushing) {
1607 			packet->ack = RCODE_GENERATION;
1608 			break;
1609 		}
1610 		fallthrough;
1611 
1612 	default:
1613 		packet->ack = RCODE_SEND_ERROR;
1614 		break;
1615 	}
1616 
1617 	packet->callback(packet, &ohci->card, packet->ack);
1618 
1619 	return 1;
1620 }
1621 
1622 static u32 get_cycle_time(struct fw_ohci *ohci);
1623 
1624 static void handle_local_rom(struct fw_ohci *ohci,
1625 			     struct fw_packet *packet, u32 csr)
1626 {
1627 	struct fw_packet response;
1628 	int tcode, length, i;
1629 
1630 	tcode = async_header_get_tcode(packet->header);
1631 	if (tcode_is_block_packet(tcode))
1632 		length = async_header_get_data_length(packet->header);
1633 	else
1634 		length = 4;
1635 
1636 	i = csr - CSR_CONFIG_ROM;
1637 	if (i + length > CONFIG_ROM_SIZE) {
1638 		fw_fill_response(&response, packet->header,
1639 				 RCODE_ADDRESS_ERROR, NULL, 0);
1640 	} else if (!tcode_is_read_request(tcode)) {
1641 		fw_fill_response(&response, packet->header,
1642 				 RCODE_TYPE_ERROR, NULL, 0);
1643 	} else {
1644 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1645 				 (void *) ohci->config_rom + i, length);
1646 	}
1647 
1648 	// Timestamping on behalf of the hardware.
1649 	response.timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
1650 	fw_core_handle_response(&ohci->card, &response);
1651 }
1652 
1653 static void handle_local_lock(struct fw_ohci *ohci,
1654 			      struct fw_packet *packet, u32 csr)
1655 {
1656 	struct fw_packet response;
1657 	int tcode, length, ext_tcode, sel, try;
1658 	__be32 *payload, lock_old;
1659 	u32 lock_arg, lock_data;
1660 
1661 	tcode = async_header_get_tcode(packet->header);
1662 	length = async_header_get_data_length(packet->header);
1663 	payload = packet->payload;
1664 	ext_tcode = async_header_get_extended_tcode(packet->header);
1665 
1666 	if (tcode == TCODE_LOCK_REQUEST &&
1667 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1668 		lock_arg = be32_to_cpu(payload[0]);
1669 		lock_data = be32_to_cpu(payload[1]);
1670 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1671 		lock_arg = 0;
1672 		lock_data = 0;
1673 	} else {
1674 		fw_fill_response(&response, packet->header,
1675 				 RCODE_TYPE_ERROR, NULL, 0);
1676 		goto out;
1677 	}
1678 
1679 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1680 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1681 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1682 	reg_write(ohci, OHCI1394_CSRControl, sel);
1683 
1684 	for (try = 0; try < 20; try++)
1685 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1686 			lock_old = cpu_to_be32(reg_read(ohci,
1687 							OHCI1394_CSRData));
1688 			fw_fill_response(&response, packet->header,
1689 					 RCODE_COMPLETE,
1690 					 &lock_old, sizeof(lock_old));
1691 			goto out;
1692 		}
1693 
1694 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
1695 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1696 
1697  out:
1698 	// Timestamping on behalf of the hardware.
1699 	response.timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
1700 	fw_core_handle_response(&ohci->card, &response);
1701 }
1702 
1703 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1704 {
1705 	u64 offset, csr;
1706 
1707 	if (ctx == &ctx->ohci->at_request_ctx) {
1708 		packet->ack = ACK_PENDING;
1709 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1710 	}
1711 
1712 	offset = async_header_get_offset(packet->header);
1713 	csr = offset - CSR_REGISTER_BASE;
1714 
1715 	/* Handle config rom reads. */
1716 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1717 		handle_local_rom(ctx->ohci, packet, csr);
1718 	else switch (csr) {
1719 	case CSR_BUS_MANAGER_ID:
1720 	case CSR_BANDWIDTH_AVAILABLE:
1721 	case CSR_CHANNELS_AVAILABLE_HI:
1722 	case CSR_CHANNELS_AVAILABLE_LO:
1723 		handle_local_lock(ctx->ohci, packet, csr);
1724 		break;
1725 	default:
1726 		if (ctx == &ctx->ohci->at_request_ctx)
1727 			fw_core_handle_request(&ctx->ohci->card, packet);
1728 		else
1729 			fw_core_handle_response(&ctx->ohci->card, packet);
1730 		break;
1731 	}
1732 
1733 	if (ctx == &ctx->ohci->at_response_ctx) {
1734 		packet->ack = ACK_COMPLETE;
1735 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1736 	}
1737 }
1738 
1739 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1740 {
1741 	unsigned long flags;
1742 	int ret;
1743 
1744 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1745 
1746 	if (async_header_get_destination(packet->header) == ctx->ohci->node_id &&
1747 	    ctx->ohci->generation == packet->generation) {
1748 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1749 
1750 		// Timestamping on behalf of the hardware.
1751 		packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ctx->ohci));
1752 
1753 		handle_local_request(ctx, packet);
1754 		return;
1755 	}
1756 
1757 	ret = at_context_queue_packet(ctx, packet);
1758 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1759 
1760 	if (ret < 0) {
1761 		// Timestamping on behalf of the hardware.
1762 		packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ctx->ohci));
1763 
1764 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1765 	}
1766 }
1767 
1768 static void detect_dead_context(struct fw_ohci *ohci,
1769 				const char *name, unsigned int regs)
1770 {
1771 	u32 ctl;
1772 
1773 	ctl = reg_read(ohci, CONTROL_SET(regs));
1774 	if (ctl & CONTEXT_DEAD)
1775 		ohci_err(ohci, "DMA context %s has stopped, error code: %s\n",
1776 			name, evts[ctl & 0x1f]);
1777 }
1778 
1779 static void handle_dead_contexts(struct fw_ohci *ohci)
1780 {
1781 	unsigned int i;
1782 	char name[8];
1783 
1784 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1785 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1786 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1787 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1788 	for (i = 0; i < 32; ++i) {
1789 		if (!(ohci->it_context_support & (1 << i)))
1790 			continue;
1791 		sprintf(name, "IT%u", i);
1792 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1793 	}
1794 	for (i = 0; i < 32; ++i) {
1795 		if (!(ohci->ir_context_support & (1 << i)))
1796 			continue;
1797 		sprintf(name, "IR%u", i);
1798 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1799 	}
1800 	/* TODO: maybe try to flush and restart the dead contexts */
1801 }
1802 
1803 static u32 cycle_timer_ticks(u32 cycle_timer)
1804 {
1805 	u32 ticks;
1806 
1807 	ticks = cycle_timer & 0xfff;
1808 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1809 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1810 
1811 	return ticks;
1812 }
1813 
1814 /*
1815  * Some controllers exhibit one or more of the following bugs when updating the
1816  * iso cycle timer register:
1817  *  - When the lowest six bits are wrapping around to zero, a read that happens
1818  *    at the same time will return garbage in the lowest ten bits.
1819  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1820  *    not incremented for about 60 ns.
1821  *  - Occasionally, the entire register reads zero.
1822  *
1823  * To catch these, we read the register three times and ensure that the
1824  * difference between each two consecutive reads is approximately the same, i.e.
1825  * less than twice the other.  Furthermore, any negative difference indicates an
1826  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1827  * execute, so we have enough precision to compute the ratio of the differences.)
1828  */
1829 static u32 get_cycle_time(struct fw_ohci *ohci)
1830 {
1831 	u32 c0, c1, c2;
1832 	u32 t0, t1, t2;
1833 	s32 diff01, diff12;
1834 	int i;
1835 
1836 	if (has_reboot_by_cycle_timer_read_quirk(ohci))
1837 		return 0;
1838 
1839 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1840 
1841 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1842 		i = 0;
1843 		c1 = c2;
1844 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1845 		do {
1846 			c0 = c1;
1847 			c1 = c2;
1848 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1849 			t0 = cycle_timer_ticks(c0);
1850 			t1 = cycle_timer_ticks(c1);
1851 			t2 = cycle_timer_ticks(c2);
1852 			diff01 = t1 - t0;
1853 			diff12 = t2 - t1;
1854 		} while ((diff01 <= 0 || diff12 <= 0 ||
1855 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1856 			 && i++ < 20);
1857 	}
1858 
1859 	return c2;
1860 }
1861 
1862 /*
1863  * This function has to be called at least every 64 seconds.  The bus_time
1864  * field stores not only the upper 25 bits of the BUS_TIME register but also
1865  * the most significant bit of the cycle timer in bit 6 so that we can detect
1866  * changes in this bit.
1867  */
1868 static u32 update_bus_time(struct fw_ohci *ohci)
1869 {
1870 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1871 
1872 	if (unlikely(!ohci->bus_time_running)) {
1873 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds);
1874 		ohci->bus_time = (lower_32_bits(ktime_get_seconds()) & ~0x7f) |
1875 		                 (cycle_time_seconds & 0x40);
1876 		ohci->bus_time_running = true;
1877 	}
1878 
1879 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1880 		ohci->bus_time += 0x40;
1881 
1882 	return ohci->bus_time | cycle_time_seconds;
1883 }
1884 
1885 static int get_status_for_port(struct fw_ohci *ohci, int port_index,
1886 			       enum phy_packet_self_id_port_status *status)
1887 {
1888 	int reg;
1889 
1890 	scoped_guard(mutex, &ohci->phy_reg_mutex) {
1891 		reg = write_phy_reg(ohci, 7, port_index);
1892 		if (reg < 0)
1893 			return reg;
1894 
1895 		reg = read_phy_reg(ohci, 8);
1896 		if (reg < 0)
1897 			return reg;
1898 	}
1899 
1900 	switch (reg & 0x0f) {
1901 	case 0x06:
1902 		// is child node (connected to parent node)
1903 		*status = PHY_PACKET_SELF_ID_PORT_STATUS_PARENT;
1904 		break;
1905 	case 0x0e:
1906 		// is parent node (connected to child node)
1907 		*status = PHY_PACKET_SELF_ID_PORT_STATUS_CHILD;
1908 		break;
1909 	default:
1910 		// not connected
1911 		*status = PHY_PACKET_SELF_ID_PORT_STATUS_NCONN;
1912 		break;
1913 	}
1914 
1915 	return 0;
1916 }
1917 
1918 static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
1919 	int self_id_count)
1920 {
1921 	unsigned int left_phy_id = phy_packet_self_id_get_phy_id(self_id);
1922 	int i;
1923 
1924 	for (i = 0; i < self_id_count; i++) {
1925 		u32 entry = ohci->self_id_buffer[i];
1926 		unsigned int right_phy_id = phy_packet_self_id_get_phy_id(entry);
1927 
1928 		if (left_phy_id == right_phy_id)
1929 			return -1;
1930 		if (left_phy_id < right_phy_id)
1931 			return i;
1932 	}
1933 	return i;
1934 }
1935 
1936 static int detect_initiated_reset(struct fw_ohci *ohci, bool *is_initiated_reset)
1937 {
1938 	int reg;
1939 
1940 	guard(mutex)(&ohci->phy_reg_mutex);
1941 
1942 	// Select page 7
1943 	reg = write_phy_reg(ohci, 7, 0xe0);
1944 	if (reg < 0)
1945 		return reg;
1946 
1947 	reg = read_phy_reg(ohci, 8);
1948 	if (reg < 0)
1949 		return reg;
1950 
1951 	// set PMODE bit
1952 	reg |= 0x40;
1953 	reg = write_phy_reg(ohci, 8, reg);
1954 	if (reg < 0)
1955 		return reg;
1956 
1957 	// read register 12
1958 	reg = read_phy_reg(ohci, 12);
1959 	if (reg < 0)
1960 		return reg;
1961 
1962 	// bit 3 indicates "initiated reset"
1963 	*is_initiated_reset = !!((reg & 0x08) == 0x08);
1964 
1965 	return 0;
1966 }
1967 
1968 /*
1969  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
1970  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
1971  * Construct the selfID from phy register contents.
1972  */
1973 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
1974 {
1975 	int reg, i, pos, err;
1976 	bool is_initiated_reset;
1977 	u32 self_id = 0;
1978 
1979 	// link active 1, speed 3, bridge 0, contender 1, more packets 0.
1980 	phy_packet_set_packet_identifier(&self_id, PHY_PACKET_PACKET_IDENTIFIER_SELF_ID);
1981 	phy_packet_self_id_zero_set_link_active(&self_id, true);
1982 	phy_packet_self_id_zero_set_scode(&self_id, SCODE_800);
1983 	phy_packet_self_id_zero_set_contender(&self_id, true);
1984 
1985 	reg = reg_read(ohci, OHCI1394_NodeID);
1986 	if (!(reg & OHCI1394_NodeID_idValid)) {
1987 		ohci_notice(ohci,
1988 			    "node ID not valid, new bus reset in progress\n");
1989 		return -EBUSY;
1990 	}
1991 	phy_packet_self_id_set_phy_id(&self_id, reg & 0x3f);
1992 
1993 	reg = ohci_read_phy_reg(&ohci->card, 4);
1994 	if (reg < 0)
1995 		return reg;
1996 	phy_packet_self_id_zero_set_power_class(&self_id, reg & 0x07);
1997 
1998 	reg = ohci_read_phy_reg(&ohci->card, 1);
1999 	if (reg < 0)
2000 		return reg;
2001 	phy_packet_self_id_zero_set_gap_count(&self_id, reg & 0x3f);
2002 
2003 	for (i = 0; i < 3; i++) {
2004 		enum phy_packet_self_id_port_status status;
2005 
2006 		err = get_status_for_port(ohci, i, &status);
2007 		if (err < 0)
2008 			return err;
2009 
2010 		self_id_sequence_set_port_status(&self_id, 1, i, status);
2011 	}
2012 
2013 	err = detect_initiated_reset(ohci, &is_initiated_reset);
2014 	if (err < 0)
2015 		return err;
2016 	phy_packet_self_id_zero_set_initiated_reset(&self_id, is_initiated_reset);
2017 
2018 	pos = get_self_id_pos(ohci, self_id, self_id_count);
2019 	if (pos >= 0) {
2020 		memmove(&(ohci->self_id_buffer[pos+1]),
2021 			&(ohci->self_id_buffer[pos]),
2022 			(self_id_count - pos) * sizeof(*ohci->self_id_buffer));
2023 		ohci->self_id_buffer[pos] = self_id;
2024 		self_id_count++;
2025 	}
2026 	return self_id_count;
2027 }
2028 
2029 static void bus_reset_work(struct work_struct *work)
2030 {
2031 	struct fw_ohci *ohci =
2032 		container_of(work, struct fw_ohci, bus_reset_work);
2033 	int self_id_count, generation, new_generation, i, j;
2034 	u32 reg, quadlet;
2035 	void *free_rom = NULL;
2036 	dma_addr_t free_rom_bus = 0;
2037 	bool is_new_root;
2038 
2039 	reg = reg_read(ohci, OHCI1394_NodeID);
2040 	if (!(reg & OHCI1394_NodeID_idValid)) {
2041 		ohci_notice(ohci,
2042 			    "node ID not valid, new bus reset in progress\n");
2043 		return;
2044 	}
2045 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
2046 		ohci_notice(ohci, "malconfigured bus\n");
2047 		return;
2048 	}
2049 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
2050 			       OHCI1394_NodeID_nodeNumber);
2051 
2052 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
2053 	if (!(ohci->is_root && is_new_root))
2054 		reg_write(ohci, OHCI1394_LinkControlSet,
2055 			  OHCI1394_LinkControl_cycleMaster);
2056 	ohci->is_root = is_new_root;
2057 
2058 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
2059 	if (ohci1394_self_id_count_is_error(reg)) {
2060 		ohci_notice(ohci, "self ID receive error\n");
2061 		return;
2062 	}
2063 	/*
2064 	 * The count in the SelfIDCount register is the number of
2065 	 * bytes in the self ID receive buffer.  Since we also receive
2066 	 * the inverted quadlets and a header quadlet, we shift one
2067 	 * bit extra to get the actual number of self IDs.
2068 	 */
2069 	self_id_count = ohci1394_self_id_count_get_size(reg) >> 1;
2070 
2071 	if (self_id_count > 252) {
2072 		ohci_notice(ohci, "bad selfIDSize (%08x)\n", reg);
2073 		return;
2074 	}
2075 
2076 	quadlet = cond_le32_to_cpu(ohci->self_id[0], has_be_header_quirk(ohci));
2077 	generation = ohci1394_self_id_receive_q0_get_generation(quadlet);
2078 	rmb();
2079 
2080 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
2081 		u32 id  = cond_le32_to_cpu(ohci->self_id[i], has_be_header_quirk(ohci));
2082 		u32 id2 = cond_le32_to_cpu(ohci->self_id[i + 1], has_be_header_quirk(ohci));
2083 
2084 		if (id != ~id2) {
2085 			/*
2086 			 * If the invalid data looks like a cycle start packet,
2087 			 * it's likely to be the result of the cycle master
2088 			 * having a wrong gap count.  In this case, the self IDs
2089 			 * so far are valid and should be processed so that the
2090 			 * bus manager can then correct the gap count.
2091 			 */
2092 			if (id == 0xffff008f) {
2093 				ohci_notice(ohci, "ignoring spurious self IDs\n");
2094 				self_id_count = j;
2095 				break;
2096 			}
2097 
2098 			ohci_notice(ohci, "bad self ID %d/%d (%08x != ~%08x)\n",
2099 				    j, self_id_count, id, id2);
2100 			return;
2101 		}
2102 		ohci->self_id_buffer[j] = id;
2103 	}
2104 
2105 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2106 		self_id_count = find_and_insert_self_id(ohci, self_id_count);
2107 		if (self_id_count < 0) {
2108 			ohci_notice(ohci,
2109 				    "could not construct local self ID\n");
2110 			return;
2111 		}
2112 	}
2113 
2114 	if (self_id_count == 0) {
2115 		ohci_notice(ohci, "no self IDs\n");
2116 		return;
2117 	}
2118 	rmb();
2119 
2120 	/*
2121 	 * Check the consistency of the self IDs we just read.  The
2122 	 * problem we face is that a new bus reset can start while we
2123 	 * read out the self IDs from the DMA buffer. If this happens,
2124 	 * the DMA buffer will be overwritten with new self IDs and we
2125 	 * will read out inconsistent data.  The OHCI specification
2126 	 * (section 11.2) recommends a technique similar to
2127 	 * linux/seqlock.h, where we remember the generation of the
2128 	 * self IDs in the buffer before reading them out and compare
2129 	 * it to the current generation after reading them out.  If
2130 	 * the two generations match we know we have a consistent set
2131 	 * of self IDs.
2132 	 */
2133 
2134 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
2135 	new_generation = ohci1394_self_id_count_get_generation(reg);
2136 	if (new_generation != generation) {
2137 		ohci_notice(ohci, "new bus reset, discarding self ids\n");
2138 		return;
2139 	}
2140 
2141 	// FIXME: Document how the locking works.
2142 	scoped_guard(spinlock_irq, &ohci->lock) {
2143 		ohci->generation = -1; // prevent AT packet queueing
2144 		context_stop(&ohci->at_request_ctx);
2145 		context_stop(&ohci->at_response_ctx);
2146 	}
2147 
2148 	/*
2149 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
2150 	 * packets in the AT queues and software needs to drain them.
2151 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
2152 	 */
2153 	at_context_flush(&ohci->at_request_ctx);
2154 	at_context_flush(&ohci->at_response_ctx);
2155 
2156 	scoped_guard(spinlock_irq, &ohci->lock) {
2157 		ohci->generation = generation;
2158 		reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
2159 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_busReset);
2160 
2161 		if (ohci->quirks & QUIRK_RESET_PACKET)
2162 			ohci->request_generation = generation;
2163 
2164 		// This next bit is unrelated to the AT context stuff but we have to do it under the
2165 		// spinlock also. If a new config rom was set up before this reset, the old one is
2166 		// now no longer in use and we can free it. Update the config rom pointers to point
2167 		// to the current config rom and clear the next_config_rom pointer so a new update
2168 		// can take place.
2169 		if (ohci->next_config_rom != NULL) {
2170 			if (ohci->next_config_rom != ohci->config_rom) {
2171 				free_rom      = ohci->config_rom;
2172 				free_rom_bus  = ohci->config_rom_bus;
2173 			}
2174 			ohci->config_rom      = ohci->next_config_rom;
2175 			ohci->config_rom_bus  = ohci->next_config_rom_bus;
2176 			ohci->next_config_rom = NULL;
2177 
2178 			// Restore config_rom image and manually update config_rom registers.
2179 			// Writing the header quadlet will indicate that the config rom is ready,
2180 			// so we do that last.
2181 			reg_write(ohci, OHCI1394_BusOptions, be32_to_cpu(ohci->config_rom[2]));
2182 			ohci->config_rom[0] = ohci->next_header;
2183 			reg_write(ohci, OHCI1394_ConfigROMhdr, be32_to_cpu(ohci->next_header));
2184 		}
2185 
2186 		if (param_remote_dma) {
2187 			reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
2188 			reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
2189 		}
2190 	}
2191 
2192 	if (free_rom)
2193 		dmam_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, free_rom, free_rom_bus);
2194 
2195 	log_selfids(ohci, generation, self_id_count);
2196 
2197 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
2198 				 self_id_count, ohci->self_id_buffer,
2199 				 ohci->csr_state_setclear_abdicate);
2200 	ohci->csr_state_setclear_abdicate = false;
2201 }
2202 
2203 static irqreturn_t irq_handler(int irq, void *data)
2204 {
2205 	struct fw_ohci *ohci = data;
2206 	u32 event, iso_event;
2207 	int i;
2208 
2209 	event = reg_read(ohci, OHCI1394_IntEventClear);
2210 
2211 	if (!event || !~event)
2212 		return IRQ_NONE;
2213 
2214 	if (unlikely(param_debug > 0)) {
2215 		dev_notice_ratelimited(ohci->card.device,
2216 				       "The debug parameter is superceded by tracepoints events, and deprecated.");
2217 	}
2218 
2219 	/*
2220 	 * busReset and postedWriteErr events must not be cleared yet
2221 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
2222 	 */
2223 	reg_write(ohci, OHCI1394_IntEventClear,
2224 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
2225 	trace_irqs(ohci->card.index, event);
2226 	log_irqs(ohci, event);
2227 	// The flag is masked again at bus_reset_work() scheduled by selfID event.
2228 	if (event & OHCI1394_busReset)
2229 		reg_write(ohci, OHCI1394_IntMaskClear, OHCI1394_busReset);
2230 
2231 	if (event & OHCI1394_selfIDComplete) {
2232 		if (trace_self_id_complete_enabled()) {
2233 			u32 reg = reg_read(ohci, OHCI1394_SelfIDCount);
2234 
2235 			trace_self_id_complete(ohci->card.index, reg, ohci->self_id,
2236 					       has_be_header_quirk(ohci));
2237 		}
2238 		queue_work(selfid_workqueue, &ohci->bus_reset_work);
2239 	}
2240 
2241 	if (event & OHCI1394_RQPkt)
2242 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
2243 
2244 	if (event & OHCI1394_RSPkt)
2245 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
2246 
2247 	if (event & OHCI1394_reqTxComplete)
2248 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
2249 
2250 	if (event & OHCI1394_respTxComplete)
2251 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
2252 
2253 	if (event & OHCI1394_isochRx) {
2254 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
2255 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
2256 
2257 		while (iso_event) {
2258 			i = ffs(iso_event) - 1;
2259 			fw_iso_context_schedule_flush_completions(&ohci->ir_context_list[i].base);
2260 			iso_event &= ~(1 << i);
2261 		}
2262 	}
2263 
2264 	if (event & OHCI1394_isochTx) {
2265 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
2266 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
2267 
2268 		while (iso_event) {
2269 			i = ffs(iso_event) - 1;
2270 			fw_iso_context_schedule_flush_completions(&ohci->it_context_list[i].base);
2271 			iso_event &= ~(1 << i);
2272 		}
2273 	}
2274 
2275 	if (unlikely(event & OHCI1394_regAccessFail))
2276 		ohci_err(ohci, "register access failure\n");
2277 
2278 	if (unlikely(event & OHCI1394_postedWriteErr)) {
2279 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
2280 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
2281 		reg_write(ohci, OHCI1394_IntEventClear,
2282 			  OHCI1394_postedWriteErr);
2283 		dev_err_ratelimited(ohci->card.device, "PCI posted write error\n");
2284 	}
2285 
2286 	if (unlikely(event & OHCI1394_cycleTooLong)) {
2287 		dev_notice_ratelimited(ohci->card.device, "isochronous cycle too long\n");
2288 		reg_write(ohci, OHCI1394_LinkControlSet,
2289 			  OHCI1394_LinkControl_cycleMaster);
2290 	}
2291 
2292 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
2293 		/*
2294 		 * We need to clear this event bit in order to make
2295 		 * cycleMatch isochronous I/O work.  In theory we should
2296 		 * stop active cycleMatch iso contexts now and restart
2297 		 * them at least two cycles later.  (FIXME?)
2298 		 */
2299 		dev_notice_ratelimited(ohci->card.device, "isochronous cycle inconsistent\n");
2300 	}
2301 
2302 	if (unlikely(event & OHCI1394_unrecoverableError))
2303 		handle_dead_contexts(ohci);
2304 
2305 	if (event & OHCI1394_cycle64Seconds) {
2306 		guard(spinlock)(&ohci->lock);
2307 		update_bus_time(ohci);
2308 	} else
2309 		flush_writes(ohci);
2310 
2311 	return IRQ_HANDLED;
2312 }
2313 
2314 static int software_reset(struct fw_ohci *ohci)
2315 {
2316 	u32 val;
2317 	int i;
2318 
2319 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
2320 	for (i = 0; i < 500; i++) {
2321 		val = reg_read(ohci, OHCI1394_HCControlSet);
2322 		if (!~val)
2323 			return -ENODEV; /* Card was ejected. */
2324 
2325 		if (!(val & OHCI1394_HCControl_softReset))
2326 			return 0;
2327 
2328 		msleep(1);
2329 	}
2330 
2331 	return -EBUSY;
2332 }
2333 
2334 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
2335 {
2336 	size_t size = length * 4;
2337 
2338 	memcpy(dest, src, size);
2339 	if (size < CONFIG_ROM_SIZE)
2340 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
2341 }
2342 
2343 static int configure_1394a_enhancements(struct fw_ohci *ohci)
2344 {
2345 	bool enable_1394a;
2346 	int ret, clear, set, offset;
2347 
2348 	/* Check if the driver should configure link and PHY. */
2349 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
2350 	      OHCI1394_HCControl_programPhyEnable))
2351 		return 0;
2352 
2353 	/* Paranoia: check whether the PHY supports 1394a, too. */
2354 	enable_1394a = false;
2355 	ret = read_phy_reg(ohci, 2);
2356 	if (ret < 0)
2357 		return ret;
2358 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2359 		ret = read_paged_phy_reg(ohci, 1, 8);
2360 		if (ret < 0)
2361 			return ret;
2362 		if (ret >= 1)
2363 			enable_1394a = true;
2364 	}
2365 
2366 	if (ohci->quirks & QUIRK_NO_1394A)
2367 		enable_1394a = false;
2368 
2369 	/* Configure PHY and link consistently. */
2370 	if (enable_1394a) {
2371 		clear = 0;
2372 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2373 	} else {
2374 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2375 		set = 0;
2376 	}
2377 	ret = update_phy_reg(ohci, 5, clear, set);
2378 	if (ret < 0)
2379 		return ret;
2380 
2381 	if (enable_1394a)
2382 		offset = OHCI1394_HCControlSet;
2383 	else
2384 		offset = OHCI1394_HCControlClear;
2385 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2386 
2387 	/* Clean up: configuration has been taken care of. */
2388 	reg_write(ohci, OHCI1394_HCControlClear,
2389 		  OHCI1394_HCControl_programPhyEnable);
2390 
2391 	return 0;
2392 }
2393 
2394 static int probe_tsb41ba3d(struct fw_ohci *ohci)
2395 {
2396 	/* TI vendor ID = 0x080028, TSB41BA3D product ID = 0x833005 (sic) */
2397 	static const u8 id[] = { 0x08, 0x00, 0x28, 0x83, 0x30, 0x05, };
2398 	int reg, i;
2399 
2400 	reg = read_phy_reg(ohci, 2);
2401 	if (reg < 0)
2402 		return reg;
2403 	if ((reg & PHY_EXTENDED_REGISTERS) != PHY_EXTENDED_REGISTERS)
2404 		return 0;
2405 
2406 	for (i = ARRAY_SIZE(id) - 1; i >= 0; i--) {
2407 		reg = read_paged_phy_reg(ohci, 1, i + 10);
2408 		if (reg < 0)
2409 			return reg;
2410 		if (reg != id[i])
2411 			return 0;
2412 	}
2413 	return 1;
2414 }
2415 
2416 static int ohci_enable(struct fw_card *card,
2417 		       const __be32 *config_rom, size_t length)
2418 {
2419 	struct fw_ohci *ohci = fw_ohci(card);
2420 	u32 lps, version, irqs;
2421 	int i, ret;
2422 
2423 	ret = software_reset(ohci);
2424 	if (ret < 0) {
2425 		ohci_err(ohci, "failed to reset ohci card\n");
2426 		return ret;
2427 	}
2428 
2429 	/*
2430 	 * Now enable LPS, which we need in order to start accessing
2431 	 * most of the registers.  In fact, on some cards (ALI M5251),
2432 	 * accessing registers in the SClk domain without LPS enabled
2433 	 * will lock up the machine.  Wait 50msec to make sure we have
2434 	 * full link enabled.  However, with some cards (well, at least
2435 	 * a JMicron PCIe card), we have to try again sometimes.
2436 	 *
2437 	 * TI TSB82AA2 + TSB81BA3(A) cards signal LPS enabled early but
2438 	 * cannot actually use the phy at that time.  These need tens of
2439 	 * millisecods pause between LPS write and first phy access too.
2440 	 */
2441 
2442 	reg_write(ohci, OHCI1394_HCControlSet,
2443 		  OHCI1394_HCControl_LPS |
2444 		  OHCI1394_HCControl_postedWriteEnable);
2445 	flush_writes(ohci);
2446 
2447 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2448 		msleep(50);
2449 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2450 		      OHCI1394_HCControl_LPS;
2451 	}
2452 
2453 	if (!lps) {
2454 		ohci_err(ohci, "failed to set Link Power Status\n");
2455 		return -EIO;
2456 	}
2457 
2458 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2459 		ret = probe_tsb41ba3d(ohci);
2460 		if (ret < 0)
2461 			return ret;
2462 		if (ret)
2463 			ohci_notice(ohci, "local TSB41BA3D phy\n");
2464 		else
2465 			ohci->quirks &= ~QUIRK_TI_SLLZ059;
2466 	}
2467 
2468 	reg_write(ohci, OHCI1394_HCControlClear,
2469 		  OHCI1394_HCControl_noByteSwapData);
2470 
2471 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2472 	reg_write(ohci, OHCI1394_LinkControlSet,
2473 		  OHCI1394_LinkControl_cycleTimerEnable |
2474 		  OHCI1394_LinkControl_cycleMaster);
2475 
2476 	reg_write(ohci, OHCI1394_ATRetries,
2477 		  OHCI1394_MAX_AT_REQ_RETRIES |
2478 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2479 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2480 		  (200 << 16));
2481 
2482 	ohci->bus_time_running = false;
2483 
2484 	for (i = 0; i < 32; i++)
2485 		if (ohci->ir_context_support & (1 << i))
2486 			reg_write(ohci, OHCI1394_IsoRcvContextControlClear(i),
2487 				  IR_CONTEXT_MULTI_CHANNEL_MODE);
2488 
2489 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2490 	if (version >= OHCI_VERSION_1_1) {
2491 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2492 			  0xfffffffe);
2493 		card->broadcast_channel_auto_allocated = true;
2494 	}
2495 
2496 	/* Get implemented bits of the priority arbitration request counter. */
2497 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2498 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2499 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2500 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2501 
2502 	reg_write(ohci, OHCI1394_PhyUpperBound, FW_MAX_PHYSICAL_RANGE >> 16);
2503 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2504 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2505 
2506 	ret = configure_1394a_enhancements(ohci);
2507 	if (ret < 0)
2508 		return ret;
2509 
2510 	/* Activate link_on bit and contender bit in our self ID packets.*/
2511 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2512 	if (ret < 0)
2513 		return ret;
2514 
2515 	/*
2516 	 * When the link is not yet enabled, the atomic config rom
2517 	 * update mechanism described below in ohci_set_config_rom()
2518 	 * is not active.  We have to update ConfigRomHeader and
2519 	 * BusOptions manually, and the write to ConfigROMmap takes
2520 	 * effect immediately.  We tie this to the enabling of the
2521 	 * link, so we have a valid config rom before enabling - the
2522 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2523 	 * values before enabling.
2524 	 *
2525 	 * However, when the ConfigROMmap is written, some controllers
2526 	 * always read back quadlets 0 and 2 from the config rom to
2527 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2528 	 * They shouldn't do that in this initial case where the link
2529 	 * isn't enabled.  This means we have to use the same
2530 	 * workaround here, setting the bus header to 0 and then write
2531 	 * the right values in the bus reset tasklet.
2532 	 */
2533 
2534 	if (config_rom) {
2535 		ohci->next_config_rom = dmam_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2536 							    &ohci->next_config_rom_bus, GFP_KERNEL);
2537 		if (ohci->next_config_rom == NULL)
2538 			return -ENOMEM;
2539 
2540 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2541 	} else {
2542 		/*
2543 		 * In the suspend case, config_rom is NULL, which
2544 		 * means that we just reuse the old config rom.
2545 		 */
2546 		ohci->next_config_rom = ohci->config_rom;
2547 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2548 	}
2549 
2550 	ohci->next_header = ohci->next_config_rom[0];
2551 	ohci->next_config_rom[0] = 0;
2552 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2553 	reg_write(ohci, OHCI1394_BusOptions,
2554 		  be32_to_cpu(ohci->next_config_rom[2]));
2555 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2556 
2557 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2558 
2559 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2560 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2561 		OHCI1394_isochTx | OHCI1394_isochRx |
2562 		OHCI1394_postedWriteErr |
2563 		OHCI1394_selfIDComplete |
2564 		OHCI1394_regAccessFail |
2565 		OHCI1394_cycleInconsistent |
2566 		OHCI1394_unrecoverableError |
2567 		OHCI1394_cycleTooLong |
2568 		OHCI1394_masterIntEnable |
2569 		OHCI1394_busReset;
2570 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2571 
2572 	reg_write(ohci, OHCI1394_HCControlSet,
2573 		  OHCI1394_HCControl_linkEnable |
2574 		  OHCI1394_HCControl_BIBimageValid);
2575 
2576 	reg_write(ohci, OHCI1394_LinkControlSet,
2577 		  OHCI1394_LinkControl_rcvSelfID |
2578 		  OHCI1394_LinkControl_rcvPhyPkt);
2579 
2580 	ar_context_run(&ohci->ar_request_ctx);
2581 	ar_context_run(&ohci->ar_response_ctx);
2582 
2583 	flush_writes(ohci);
2584 
2585 	/* We are ready to go, reset bus to finish initialization. */
2586 	fw_schedule_bus_reset(&ohci->card, false, true);
2587 
2588 	return 0;
2589 }
2590 
2591 static int ohci_set_config_rom(struct fw_card *card,
2592 			       const __be32 *config_rom, size_t length)
2593 {
2594 	struct fw_ohci *ohci;
2595 	__be32 *next_config_rom;
2596 	dma_addr_t next_config_rom_bus;
2597 
2598 	ohci = fw_ohci(card);
2599 
2600 	/*
2601 	 * When the OHCI controller is enabled, the config rom update
2602 	 * mechanism is a bit tricky, but easy enough to use.  See
2603 	 * section 5.5.6 in the OHCI specification.
2604 	 *
2605 	 * The OHCI controller caches the new config rom address in a
2606 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2607 	 * for the changes to take place.  When the bus reset is
2608 	 * detected, the controller loads the new values for the
2609 	 * ConfigRomHeader and BusOptions registers from the specified
2610 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2611 	 * shadow register. All automatically and atomically.
2612 	 *
2613 	 * Now, there's a twist to this story.  The automatic load of
2614 	 * ConfigRomHeader and BusOptions doesn't honor the
2615 	 * noByteSwapData bit, so with a be32 config rom, the
2616 	 * controller will load be32 values in to these registers
2617 	 * during the atomic update, even on litte endian
2618 	 * architectures.  The workaround we use is to put a 0 in the
2619 	 * header quadlet; 0 is endian agnostic and means that the
2620 	 * config rom isn't ready yet.  In the bus reset tasklet we
2621 	 * then set up the real values for the two registers.
2622 	 *
2623 	 * We use ohci->lock to avoid racing with the code that sets
2624 	 * ohci->next_config_rom to NULL (see bus_reset_work).
2625 	 */
2626 
2627 	next_config_rom = dmam_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2628 					      &next_config_rom_bus, GFP_KERNEL);
2629 	if (next_config_rom == NULL)
2630 		return -ENOMEM;
2631 
2632 	scoped_guard(spinlock_irq, &ohci->lock) {
2633 		// If there is not an already pending config_rom update, push our new allocation
2634 		// into the ohci->next_config_rom and then mark the local variable as null so that
2635 		// we won't deallocate the new buffer.
2636 		//
2637 		// OTOH, if there is a pending config_rom update, just use that buffer with the new
2638 		// config_rom data, and let this routine free the unused DMA allocation.
2639 		if (ohci->next_config_rom == NULL) {
2640 			ohci->next_config_rom = next_config_rom;
2641 			ohci->next_config_rom_bus = next_config_rom_bus;
2642 			next_config_rom = NULL;
2643 		}
2644 
2645 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2646 
2647 		ohci->next_header = config_rom[0];
2648 		ohci->next_config_rom[0] = 0;
2649 
2650 		reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2651 	}
2652 
2653 	/* If we didn't use the DMA allocation, delete it. */
2654 	if (next_config_rom != NULL) {
2655 		dmam_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, next_config_rom,
2656 				   next_config_rom_bus);
2657 	}
2658 
2659 	/*
2660 	 * Now initiate a bus reset to have the changes take
2661 	 * effect. We clean up the old config rom memory and DMA
2662 	 * mappings in the bus reset tasklet, since the OHCI
2663 	 * controller could need to access it before the bus reset
2664 	 * takes effect.
2665 	 */
2666 
2667 	fw_schedule_bus_reset(&ohci->card, true, true);
2668 
2669 	return 0;
2670 }
2671 
2672 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2673 {
2674 	struct fw_ohci *ohci = fw_ohci(card);
2675 
2676 	at_context_transmit(&ohci->at_request_ctx, packet);
2677 }
2678 
2679 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2680 {
2681 	struct fw_ohci *ohci = fw_ohci(card);
2682 
2683 	at_context_transmit(&ohci->at_response_ctx, packet);
2684 }
2685 
2686 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2687 {
2688 	struct fw_ohci *ohci = fw_ohci(card);
2689 	struct context *ctx = &ohci->at_request_ctx;
2690 	struct driver_data *driver_data = packet->driver_data;
2691 	int ret = -ENOENT;
2692 
2693 	tasklet_disable_in_atomic(&ctx->tasklet);
2694 
2695 	if (packet->ack != 0)
2696 		goto out;
2697 
2698 	if (packet->payload_mapped)
2699 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2700 				 packet->payload_length, DMA_TO_DEVICE);
2701 
2702 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, 0x20);
2703 	driver_data->packet = NULL;
2704 	packet->ack = RCODE_CANCELLED;
2705 
2706 	// Timestamping on behalf of the hardware.
2707 	packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
2708 
2709 	packet->callback(packet, &ohci->card, packet->ack);
2710 	ret = 0;
2711  out:
2712 	tasklet_enable(&ctx->tasklet);
2713 
2714 	return ret;
2715 }
2716 
2717 static int ohci_enable_phys_dma(struct fw_card *card,
2718 				int node_id, int generation)
2719 {
2720 	struct fw_ohci *ohci = fw_ohci(card);
2721 	int n, ret = 0;
2722 
2723 	if (param_remote_dma)
2724 		return 0;
2725 
2726 	/*
2727 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2728 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2729 	 */
2730 
2731 	guard(spinlock_irqsave)(&ohci->lock);
2732 
2733 	if (ohci->generation != generation)
2734 		return -ESTALE;
2735 
2736 	/*
2737 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2738 	 * enabled for _all_ nodes on remote buses.
2739 	 */
2740 
2741 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2742 	if (n < 32)
2743 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2744 	else
2745 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2746 
2747 	flush_writes(ohci);
2748 
2749 	return ret;
2750 }
2751 
2752 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2753 {
2754 	struct fw_ohci *ohci = fw_ohci(card);
2755 	u32 value;
2756 
2757 	switch (csr_offset) {
2758 	case CSR_STATE_CLEAR:
2759 	case CSR_STATE_SET:
2760 		if (ohci->is_root &&
2761 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2762 		     OHCI1394_LinkControl_cycleMaster))
2763 			value = CSR_STATE_BIT_CMSTR;
2764 		else
2765 			value = 0;
2766 		if (ohci->csr_state_setclear_abdicate)
2767 			value |= CSR_STATE_BIT_ABDICATE;
2768 
2769 		return value;
2770 
2771 	case CSR_NODE_IDS:
2772 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2773 
2774 	case CSR_CYCLE_TIME:
2775 		return get_cycle_time(ohci);
2776 
2777 	case CSR_BUS_TIME:
2778 	{
2779 		// We might be called just after the cycle timer has wrapped around but just before
2780 		// the cycle64Seconds handler, so we better check here, too, if the bus time needs
2781 		// to be updated.
2782 
2783 		guard(spinlock_irqsave)(&ohci->lock);
2784 		return update_bus_time(ohci);
2785 	}
2786 	case CSR_BUSY_TIMEOUT:
2787 		value = reg_read(ohci, OHCI1394_ATRetries);
2788 		return (value >> 4) & 0x0ffff00f;
2789 
2790 	case CSR_PRIORITY_BUDGET:
2791 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2792 			(ohci->pri_req_max << 8);
2793 
2794 	default:
2795 		WARN_ON(1);
2796 		return 0;
2797 	}
2798 }
2799 
2800 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2801 {
2802 	struct fw_ohci *ohci = fw_ohci(card);
2803 
2804 	switch (csr_offset) {
2805 	case CSR_STATE_CLEAR:
2806 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2807 			reg_write(ohci, OHCI1394_LinkControlClear,
2808 				  OHCI1394_LinkControl_cycleMaster);
2809 			flush_writes(ohci);
2810 		}
2811 		if (value & CSR_STATE_BIT_ABDICATE)
2812 			ohci->csr_state_setclear_abdicate = false;
2813 		break;
2814 
2815 	case CSR_STATE_SET:
2816 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2817 			reg_write(ohci, OHCI1394_LinkControlSet,
2818 				  OHCI1394_LinkControl_cycleMaster);
2819 			flush_writes(ohci);
2820 		}
2821 		if (value & CSR_STATE_BIT_ABDICATE)
2822 			ohci->csr_state_setclear_abdicate = true;
2823 		break;
2824 
2825 	case CSR_NODE_IDS:
2826 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2827 		flush_writes(ohci);
2828 		break;
2829 
2830 	case CSR_CYCLE_TIME:
2831 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2832 		reg_write(ohci, OHCI1394_IntEventSet,
2833 			  OHCI1394_cycleInconsistent);
2834 		flush_writes(ohci);
2835 		break;
2836 
2837 	case CSR_BUS_TIME:
2838 	{
2839 		guard(spinlock_irqsave)(&ohci->lock);
2840 		ohci->bus_time = (update_bus_time(ohci) & 0x40) | (value & ~0x7f);
2841 		break;
2842 	}
2843 	case CSR_BUSY_TIMEOUT:
2844 		value = (value & 0xf) | ((value & 0xf) << 4) |
2845 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2846 		reg_write(ohci, OHCI1394_ATRetries, value);
2847 		flush_writes(ohci);
2848 		break;
2849 
2850 	case CSR_PRIORITY_BUDGET:
2851 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2852 		flush_writes(ohci);
2853 		break;
2854 
2855 	default:
2856 		WARN_ON(1);
2857 		break;
2858 	}
2859 }
2860 
2861 static void flush_iso_completions(struct iso_context *ctx, enum fw_iso_context_completions_cause cause)
2862 {
2863 	trace_isoc_inbound_single_completions(&ctx->base, ctx->last_timestamp, cause, ctx->header,
2864 					      ctx->header_length);
2865 	trace_isoc_outbound_completions(&ctx->base, ctx->last_timestamp, cause, ctx->header,
2866 					ctx->header_length);
2867 
2868 	ctx->base.callback.sc(&ctx->base, ctx->last_timestamp,
2869 			      ctx->header_length, ctx->header,
2870 			      ctx->base.callback_data);
2871 	ctx->header_length = 0;
2872 }
2873 
2874 static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
2875 {
2876 	u32 *ctx_hdr;
2877 
2878 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
2879 		if (ctx->base.drop_overflow_headers)
2880 			return;
2881 		flush_iso_completions(ctx, FW_ISO_CONTEXT_COMPLETIONS_CAUSE_HEADER_OVERFLOW);
2882 	}
2883 
2884 	ctx_hdr = ctx->header + ctx->header_length;
2885 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
2886 
2887 	/*
2888 	 * The two iso header quadlets are byteswapped to little
2889 	 * endian by the controller, but we want to present them
2890 	 * as big endian for consistency with the bus endianness.
2891 	 */
2892 	if (ctx->base.header_size > 0)
2893 		ctx_hdr[0] = swab32(dma_hdr[1]); /* iso packet header */
2894 	if (ctx->base.header_size > 4)
2895 		ctx_hdr[1] = swab32(dma_hdr[0]); /* timestamp */
2896 	if (ctx->base.header_size > 8)
2897 		memcpy(&ctx_hdr[2], &dma_hdr[2], ctx->base.header_size - 8);
2898 	ctx->header_length += ctx->base.header_size;
2899 }
2900 
2901 static int handle_ir_packet_per_buffer(struct context *context,
2902 				       struct descriptor *d,
2903 				       struct descriptor *last)
2904 {
2905 	struct iso_context *ctx =
2906 		container_of(context, struct iso_context, context);
2907 	struct descriptor *pd;
2908 	u32 buffer_dma;
2909 
2910 	for (pd = d; pd <= last; pd++)
2911 		if (pd->transfer_status)
2912 			break;
2913 	if (pd > last)
2914 		/* Descriptor(s) not done yet, stop iteration */
2915 		return 0;
2916 
2917 	while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
2918 		d++;
2919 		buffer_dma = le32_to_cpu(d->data_address);
2920 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2921 					      buffer_dma & PAGE_MASK,
2922 					      buffer_dma & ~PAGE_MASK,
2923 					      le16_to_cpu(d->req_count),
2924 					      DMA_FROM_DEVICE);
2925 	}
2926 
2927 	copy_iso_headers(ctx, (u32 *) (last + 1));
2928 
2929 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2930 		flush_iso_completions(ctx, FW_ISO_CONTEXT_COMPLETIONS_CAUSE_INTERRUPT);
2931 
2932 	return 1;
2933 }
2934 
2935 /* d == last because each descriptor block is only a single descriptor. */
2936 static int handle_ir_buffer_fill(struct context *context,
2937 				 struct descriptor *d,
2938 				 struct descriptor *last)
2939 {
2940 	struct iso_context *ctx =
2941 		container_of(context, struct iso_context, context);
2942 	unsigned int req_count, res_count, completed;
2943 	u32 buffer_dma;
2944 
2945 	req_count = le16_to_cpu(last->req_count);
2946 	res_count = le16_to_cpu(READ_ONCE(last->res_count));
2947 	completed = req_count - res_count;
2948 	buffer_dma = le32_to_cpu(last->data_address);
2949 
2950 	if (completed > 0) {
2951 		ctx->mc_buffer_bus = buffer_dma;
2952 		ctx->mc_completed = completed;
2953 	}
2954 
2955 	if (res_count != 0)
2956 		/* Descriptor(s) not done yet, stop iteration */
2957 		return 0;
2958 
2959 	dma_sync_single_range_for_cpu(context->ohci->card.device,
2960 				      buffer_dma & PAGE_MASK,
2961 				      buffer_dma & ~PAGE_MASK,
2962 				      completed, DMA_FROM_DEVICE);
2963 
2964 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) {
2965 		trace_isoc_inbound_multiple_completions(&ctx->base, completed,
2966 							FW_ISO_CONTEXT_COMPLETIONS_CAUSE_INTERRUPT);
2967 
2968 		ctx->base.callback.mc(&ctx->base,
2969 				      buffer_dma + completed,
2970 				      ctx->base.callback_data);
2971 		ctx->mc_completed = 0;
2972 	}
2973 
2974 	return 1;
2975 }
2976 
2977 static void flush_ir_buffer_fill(struct iso_context *ctx)
2978 {
2979 	dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
2980 				      ctx->mc_buffer_bus & PAGE_MASK,
2981 				      ctx->mc_buffer_bus & ~PAGE_MASK,
2982 				      ctx->mc_completed, DMA_FROM_DEVICE);
2983 
2984 	trace_isoc_inbound_multiple_completions(&ctx->base, ctx->mc_completed,
2985 						FW_ISO_CONTEXT_COMPLETIONS_CAUSE_FLUSH);
2986 
2987 	ctx->base.callback.mc(&ctx->base,
2988 			      ctx->mc_buffer_bus + ctx->mc_completed,
2989 			      ctx->base.callback_data);
2990 	ctx->mc_completed = 0;
2991 }
2992 
2993 static inline void sync_it_packet_for_cpu(struct context *context,
2994 					  struct descriptor *pd)
2995 {
2996 	__le16 control;
2997 	u32 buffer_dma;
2998 
2999 	/* only packets beginning with OUTPUT_MORE* have data buffers */
3000 	if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
3001 		return;
3002 
3003 	/* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
3004 	pd += 2;
3005 
3006 	/*
3007 	 * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
3008 	 * data buffer is in the context program's coherent page and must not
3009 	 * be synced.
3010 	 */
3011 	if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
3012 	    (context->current_bus          & PAGE_MASK)) {
3013 		if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
3014 			return;
3015 		pd++;
3016 	}
3017 
3018 	do {
3019 		buffer_dma = le32_to_cpu(pd->data_address);
3020 		dma_sync_single_range_for_cpu(context->ohci->card.device,
3021 					      buffer_dma & PAGE_MASK,
3022 					      buffer_dma & ~PAGE_MASK,
3023 					      le16_to_cpu(pd->req_count),
3024 					      DMA_TO_DEVICE);
3025 		control = pd->control;
3026 		pd++;
3027 	} while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
3028 }
3029 
3030 static int handle_it_packet(struct context *context,
3031 			    struct descriptor *d,
3032 			    struct descriptor *last)
3033 {
3034 	struct iso_context *ctx =
3035 		container_of(context, struct iso_context, context);
3036 	struct descriptor *pd;
3037 	__be32 *ctx_hdr;
3038 
3039 	for (pd = d; pd <= last; pd++)
3040 		if (pd->transfer_status)
3041 			break;
3042 	if (pd > last)
3043 		/* Descriptor(s) not done yet, stop iteration */
3044 		return 0;
3045 
3046 	sync_it_packet_for_cpu(context, d);
3047 
3048 	if (ctx->header_length + 4 > PAGE_SIZE) {
3049 		if (ctx->base.drop_overflow_headers)
3050 			return 1;
3051 		flush_iso_completions(ctx, FW_ISO_CONTEXT_COMPLETIONS_CAUSE_HEADER_OVERFLOW);
3052 	}
3053 
3054 	ctx_hdr = ctx->header + ctx->header_length;
3055 	ctx->last_timestamp = le16_to_cpu(last->res_count);
3056 	/* Present this value as big-endian to match the receive code */
3057 	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
3058 			       le16_to_cpu(pd->res_count));
3059 	ctx->header_length += 4;
3060 
3061 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
3062 		flush_iso_completions(ctx, FW_ISO_CONTEXT_COMPLETIONS_CAUSE_INTERRUPT);
3063 
3064 	return 1;
3065 }
3066 
3067 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
3068 {
3069 	u32 hi = channels >> 32, lo = channels;
3070 
3071 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
3072 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
3073 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
3074 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
3075 	ohci->mc_channels = channels;
3076 }
3077 
3078 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
3079 				int type, int channel, size_t header_size)
3080 {
3081 	struct fw_ohci *ohci = fw_ohci(card);
3082 	struct iso_context *ctx;
3083 	descriptor_callback_t callback;
3084 	u64 *channels;
3085 	u32 *mask, regs;
3086 	int index, ret = -EBUSY;
3087 
3088 	scoped_guard(spinlock_irq, &ohci->lock) {
3089 		switch (type) {
3090 		case FW_ISO_CONTEXT_TRANSMIT:
3091 			mask     = &ohci->it_context_mask;
3092 			callback = handle_it_packet;
3093 			index    = ffs(*mask) - 1;
3094 			if (index >= 0) {
3095 				*mask &= ~(1 << index);
3096 				regs = OHCI1394_IsoXmitContextBase(index);
3097 				ctx  = &ohci->it_context_list[index];
3098 			}
3099 			break;
3100 
3101 		case FW_ISO_CONTEXT_RECEIVE:
3102 			channels = &ohci->ir_context_channels;
3103 			mask     = &ohci->ir_context_mask;
3104 			callback = handle_ir_packet_per_buffer;
3105 			index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
3106 			if (index >= 0) {
3107 				*channels &= ~(1ULL << channel);
3108 				*mask     &= ~(1 << index);
3109 				regs = OHCI1394_IsoRcvContextBase(index);
3110 				ctx  = &ohci->ir_context_list[index];
3111 			}
3112 			break;
3113 
3114 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3115 			mask     = &ohci->ir_context_mask;
3116 			callback = handle_ir_buffer_fill;
3117 			index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
3118 			if (index >= 0) {
3119 				ohci->mc_allocated = true;
3120 				*mask &= ~(1 << index);
3121 				regs = OHCI1394_IsoRcvContextBase(index);
3122 				ctx  = &ohci->ir_context_list[index];
3123 			}
3124 			break;
3125 
3126 		default:
3127 			index = -1;
3128 			ret = -ENOSYS;
3129 		}
3130 
3131 		if (index < 0)
3132 			return ERR_PTR(ret);
3133 	}
3134 
3135 	memset(ctx, 0, sizeof(*ctx));
3136 	ctx->header_length = 0;
3137 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
3138 	if (ctx->header == NULL) {
3139 		ret = -ENOMEM;
3140 		goto out;
3141 	}
3142 	ret = context_init(&ctx->context, ohci, regs, callback);
3143 	if (ret < 0)
3144 		goto out_with_header;
3145 	fw_iso_context_init_work(&ctx->base, ohci_isoc_context_work);
3146 
3147 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
3148 		set_multichannel_mask(ohci, 0);
3149 		ctx->mc_completed = 0;
3150 	}
3151 
3152 	return &ctx->base;
3153 
3154  out_with_header:
3155 	free_page((unsigned long)ctx->header);
3156  out:
3157 	scoped_guard(spinlock_irq, &ohci->lock) {
3158 		switch (type) {
3159 		case FW_ISO_CONTEXT_RECEIVE:
3160 			*channels |= 1ULL << channel;
3161 			break;
3162 
3163 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3164 			ohci->mc_allocated = false;
3165 			break;
3166 		}
3167 		*mask |= 1 << index;
3168 	}
3169 
3170 	return ERR_PTR(ret);
3171 }
3172 
3173 static int ohci_start_iso(struct fw_iso_context *base,
3174 			  s32 cycle, u32 sync, u32 tags)
3175 {
3176 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3177 	struct fw_ohci *ohci = ctx->context.ohci;
3178 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
3179 	int index;
3180 
3181 	/* the controller cannot start without any queued packets */
3182 	if (ctx->context.last->branch_address == 0)
3183 		return -ENODATA;
3184 
3185 	switch (ctx->base.type) {
3186 	case FW_ISO_CONTEXT_TRANSMIT:
3187 		index = ctx - ohci->it_context_list;
3188 		match = 0;
3189 		if (cycle >= 0)
3190 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
3191 				(cycle & 0x7fff) << 16;
3192 
3193 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
3194 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
3195 		context_run(&ctx->context, match);
3196 		break;
3197 
3198 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3199 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
3200 		fallthrough;
3201 	case FW_ISO_CONTEXT_RECEIVE:
3202 		index = ctx - ohci->ir_context_list;
3203 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
3204 		if (cycle >= 0) {
3205 			match |= (cycle & 0x07fff) << 12;
3206 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
3207 		}
3208 
3209 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
3210 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
3211 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
3212 		context_run(&ctx->context, control);
3213 
3214 		ctx->sync = sync;
3215 		ctx->tags = tags;
3216 
3217 		break;
3218 	}
3219 
3220 	return 0;
3221 }
3222 
3223 static int ohci_stop_iso(struct fw_iso_context *base)
3224 {
3225 	struct fw_ohci *ohci = fw_ohci(base->card);
3226 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3227 	int index;
3228 
3229 	switch (ctx->base.type) {
3230 	case FW_ISO_CONTEXT_TRANSMIT:
3231 		index = ctx - ohci->it_context_list;
3232 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
3233 		break;
3234 
3235 	case FW_ISO_CONTEXT_RECEIVE:
3236 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3237 		index = ctx - ohci->ir_context_list;
3238 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
3239 		break;
3240 	}
3241 	flush_writes(ohci);
3242 	context_stop(&ctx->context);
3243 
3244 	return 0;
3245 }
3246 
3247 static void ohci_free_iso_context(struct fw_iso_context *base)
3248 {
3249 	struct fw_ohci *ohci = fw_ohci(base->card);
3250 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3251 	int index;
3252 
3253 	ohci_stop_iso(base);
3254 	context_release(&ctx->context);
3255 	free_page((unsigned long)ctx->header);
3256 
3257 	guard(spinlock_irqsave)(&ohci->lock);
3258 
3259 	switch (base->type) {
3260 	case FW_ISO_CONTEXT_TRANSMIT:
3261 		index = ctx - ohci->it_context_list;
3262 		ohci->it_context_mask |= 1 << index;
3263 		break;
3264 
3265 	case FW_ISO_CONTEXT_RECEIVE:
3266 		index = ctx - ohci->ir_context_list;
3267 		ohci->ir_context_mask |= 1 << index;
3268 		ohci->ir_context_channels |= 1ULL << base->channel;
3269 		break;
3270 
3271 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3272 		index = ctx - ohci->ir_context_list;
3273 		ohci->ir_context_mask |= 1 << index;
3274 		ohci->ir_context_channels |= ohci->mc_channels;
3275 		ohci->mc_channels = 0;
3276 		ohci->mc_allocated = false;
3277 		break;
3278 	}
3279 }
3280 
3281 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
3282 {
3283 	struct fw_ohci *ohci = fw_ohci(base->card);
3284 
3285 	switch (base->type) {
3286 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3287 	{
3288 		guard(spinlock_irqsave)(&ohci->lock);
3289 
3290 		// Don't allow multichannel to grab other contexts' channels.
3291 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
3292 			*channels = ohci->ir_context_channels;
3293 			return -EBUSY;
3294 		} else {
3295 			set_multichannel_mask(ohci, *channels);
3296 			return 0;
3297 		}
3298 	}
3299 	default:
3300 		return -EINVAL;
3301 	}
3302 }
3303 
3304 #ifdef CONFIG_PM
3305 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
3306 {
3307 	int i;
3308 	struct iso_context *ctx;
3309 
3310 	for (i = 0 ; i < ohci->n_ir ; i++) {
3311 		ctx = &ohci->ir_context_list[i];
3312 		if (ctx->context.running)
3313 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3314 	}
3315 
3316 	for (i = 0 ; i < ohci->n_it ; i++) {
3317 		ctx = &ohci->it_context_list[i];
3318 		if (ctx->context.running)
3319 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3320 	}
3321 }
3322 #endif
3323 
3324 static int queue_iso_transmit(struct iso_context *ctx,
3325 			      struct fw_iso_packet *packet,
3326 			      struct fw_iso_buffer *buffer,
3327 			      unsigned long payload)
3328 {
3329 	struct descriptor *d, *last, *pd;
3330 	struct fw_iso_packet *p;
3331 	__le32 *header;
3332 	dma_addr_t d_bus, page_bus;
3333 	u32 z, header_z, payload_z, irq;
3334 	u32 payload_index, payload_end_index, next_page_index;
3335 	int page, end_page, i, length, offset;
3336 
3337 	p = packet;
3338 	payload_index = payload;
3339 
3340 	if (p->skip)
3341 		z = 1;
3342 	else
3343 		z = 2;
3344 	if (p->header_length > 0)
3345 		z++;
3346 
3347 	/* Determine the first page the payload isn't contained in. */
3348 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
3349 	if (p->payload_length > 0)
3350 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
3351 	else
3352 		payload_z = 0;
3353 
3354 	z += payload_z;
3355 
3356 	/* Get header size in number of descriptors. */
3357 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
3358 
3359 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
3360 	if (d == NULL)
3361 		return -ENOMEM;
3362 
3363 	if (!p->skip) {
3364 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
3365 		d[0].req_count = cpu_to_le16(8);
3366 		/*
3367 		 * Link the skip address to this descriptor itself.  This causes
3368 		 * a context to skip a cycle whenever lost cycles or FIFO
3369 		 * overruns occur, without dropping the data.  The application
3370 		 * should then decide whether this is an error condition or not.
3371 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
3372 		 */
3373 		d[0].branch_address = cpu_to_le32(d_bus | z);
3374 
3375 		header = (__le32 *) &d[1];
3376 
3377 		ohci1394_it_data_set_speed(header, ctx->base.speed);
3378 		ohci1394_it_data_set_tag(header, p->tag);
3379 		ohci1394_it_data_set_channel(header, ctx->base.channel);
3380 		ohci1394_it_data_set_tcode(header, TCODE_STREAM_DATA);
3381 		ohci1394_it_data_set_sync(header, p->sy);
3382 
3383 		ohci1394_it_data_set_data_length(header, p->header_length + p->payload_length);
3384 	}
3385 
3386 	if (p->header_length > 0) {
3387 		d[2].req_count    = cpu_to_le16(p->header_length);
3388 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
3389 		memcpy(&d[z], p->header, p->header_length);
3390 	}
3391 
3392 	pd = d + z - payload_z;
3393 	payload_end_index = payload_index + p->payload_length;
3394 	for (i = 0; i < payload_z; i++) {
3395 		page               = payload_index >> PAGE_SHIFT;
3396 		offset             = payload_index & ~PAGE_MASK;
3397 		next_page_index    = (page + 1) << PAGE_SHIFT;
3398 		length             =
3399 			min(next_page_index, payload_end_index) - payload_index;
3400 		pd[i].req_count    = cpu_to_le16(length);
3401 
3402 		page_bus = page_private(buffer->pages[page]);
3403 		pd[i].data_address = cpu_to_le32(page_bus + offset);
3404 
3405 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3406 						 page_bus, offset, length,
3407 						 DMA_TO_DEVICE);
3408 
3409 		payload_index += length;
3410 	}
3411 
3412 	if (p->interrupt)
3413 		irq = DESCRIPTOR_IRQ_ALWAYS;
3414 	else
3415 		irq = DESCRIPTOR_NO_IRQ;
3416 
3417 	last = z == 2 ? d : d + z - 1;
3418 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
3419 				     DESCRIPTOR_STATUS |
3420 				     DESCRIPTOR_BRANCH_ALWAYS |
3421 				     irq);
3422 
3423 	context_append(&ctx->context, d, z, header_z);
3424 
3425 	return 0;
3426 }
3427 
3428 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
3429 				       struct fw_iso_packet *packet,
3430 				       struct fw_iso_buffer *buffer,
3431 				       unsigned long payload)
3432 {
3433 	struct device *device = ctx->context.ohci->card.device;
3434 	struct descriptor *d, *pd;
3435 	dma_addr_t d_bus, page_bus;
3436 	u32 z, header_z, rest;
3437 	int i, j, length;
3438 	int page, offset, packet_count, header_size, payload_per_buffer;
3439 
3440 	/*
3441 	 * The OHCI controller puts the isochronous header and trailer in the
3442 	 * buffer, so we need at least 8 bytes.
3443 	 */
3444 	packet_count = packet->header_length / ctx->base.header_size;
3445 	header_size  = max(ctx->base.header_size, (size_t)8);
3446 
3447 	/* Get header size in number of descriptors. */
3448 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
3449 	page     = payload >> PAGE_SHIFT;
3450 	offset   = payload & ~PAGE_MASK;
3451 	payload_per_buffer = packet->payload_length / packet_count;
3452 
3453 	for (i = 0; i < packet_count; i++) {
3454 		/* d points to the header descriptor */
3455 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
3456 		d = context_get_descriptors(&ctx->context,
3457 				z + header_z, &d_bus);
3458 		if (d == NULL)
3459 			return -ENOMEM;
3460 
3461 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3462 					      DESCRIPTOR_INPUT_MORE);
3463 		if (packet->skip && i == 0)
3464 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3465 		d->req_count    = cpu_to_le16(header_size);
3466 		d->res_count    = d->req_count;
3467 		d->transfer_status = 0;
3468 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3469 
3470 		rest = payload_per_buffer;
3471 		pd = d;
3472 		for (j = 1; j < z; j++) {
3473 			pd++;
3474 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3475 						  DESCRIPTOR_INPUT_MORE);
3476 
3477 			if (offset + rest < PAGE_SIZE)
3478 				length = rest;
3479 			else
3480 				length = PAGE_SIZE - offset;
3481 			pd->req_count = cpu_to_le16(length);
3482 			pd->res_count = pd->req_count;
3483 			pd->transfer_status = 0;
3484 
3485 			page_bus = page_private(buffer->pages[page]);
3486 			pd->data_address = cpu_to_le32(page_bus + offset);
3487 
3488 			dma_sync_single_range_for_device(device, page_bus,
3489 							 offset, length,
3490 							 DMA_FROM_DEVICE);
3491 
3492 			offset = (offset + length) & ~PAGE_MASK;
3493 			rest -= length;
3494 			if (offset == 0)
3495 				page++;
3496 		}
3497 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3498 					  DESCRIPTOR_INPUT_LAST |
3499 					  DESCRIPTOR_BRANCH_ALWAYS);
3500 		if (packet->interrupt && i == packet_count - 1)
3501 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3502 
3503 		context_append(&ctx->context, d, z, header_z);
3504 	}
3505 
3506 	return 0;
3507 }
3508 
3509 static int queue_iso_buffer_fill(struct iso_context *ctx,
3510 				 struct fw_iso_packet *packet,
3511 				 struct fw_iso_buffer *buffer,
3512 				 unsigned long payload)
3513 {
3514 	struct descriptor *d;
3515 	dma_addr_t d_bus, page_bus;
3516 	int page, offset, rest, z, i, length;
3517 
3518 	page   = payload >> PAGE_SHIFT;
3519 	offset = payload & ~PAGE_MASK;
3520 	rest   = packet->payload_length;
3521 
3522 	/* We need one descriptor for each page in the buffer. */
3523 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3524 
3525 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3526 		return -EFAULT;
3527 
3528 	for (i = 0; i < z; i++) {
3529 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3530 		if (d == NULL)
3531 			return -ENOMEM;
3532 
3533 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3534 					 DESCRIPTOR_BRANCH_ALWAYS);
3535 		if (packet->skip && i == 0)
3536 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3537 		if (packet->interrupt && i == z - 1)
3538 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3539 
3540 		if (offset + rest < PAGE_SIZE)
3541 			length = rest;
3542 		else
3543 			length = PAGE_SIZE - offset;
3544 		d->req_count = cpu_to_le16(length);
3545 		d->res_count = d->req_count;
3546 		d->transfer_status = 0;
3547 
3548 		page_bus = page_private(buffer->pages[page]);
3549 		d->data_address = cpu_to_le32(page_bus + offset);
3550 
3551 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3552 						 page_bus, offset, length,
3553 						 DMA_FROM_DEVICE);
3554 
3555 		rest -= length;
3556 		offset = 0;
3557 		page++;
3558 
3559 		context_append(&ctx->context, d, 1, 0);
3560 	}
3561 
3562 	return 0;
3563 }
3564 
3565 static int ohci_queue_iso(struct fw_iso_context *base,
3566 			  struct fw_iso_packet *packet,
3567 			  struct fw_iso_buffer *buffer,
3568 			  unsigned long payload)
3569 {
3570 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3571 
3572 	guard(spinlock_irqsave)(&ctx->context.ohci->lock);
3573 
3574 	switch (base->type) {
3575 	case FW_ISO_CONTEXT_TRANSMIT:
3576 		return queue_iso_transmit(ctx, packet, buffer, payload);
3577 	case FW_ISO_CONTEXT_RECEIVE:
3578 		return queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3579 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3580 		return queue_iso_buffer_fill(ctx, packet, buffer, payload);
3581 	default:
3582 		return -ENOSYS;
3583 	}
3584 }
3585 
3586 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3587 {
3588 	struct context *ctx =
3589 			&container_of(base, struct iso_context, base)->context;
3590 
3591 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3592 }
3593 
3594 static int ohci_flush_iso_completions(struct fw_iso_context *base)
3595 {
3596 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3597 	int ret = 0;
3598 
3599 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
3600 		ohci_isoc_context_work(&base->work);
3601 
3602 		switch (base->type) {
3603 		case FW_ISO_CONTEXT_TRANSMIT:
3604 		case FW_ISO_CONTEXT_RECEIVE:
3605 			if (ctx->header_length != 0)
3606 				flush_iso_completions(ctx, FW_ISO_CONTEXT_COMPLETIONS_CAUSE_FLUSH);
3607 			break;
3608 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3609 			if (ctx->mc_completed != 0)
3610 				flush_ir_buffer_fill(ctx);
3611 			break;
3612 		default:
3613 			ret = -ENOSYS;
3614 		}
3615 
3616 		clear_bit_unlock(0, &ctx->flushing_completions);
3617 		smp_mb__after_atomic();
3618 	}
3619 
3620 	return ret;
3621 }
3622 
3623 static const struct fw_card_driver ohci_driver = {
3624 	.enable			= ohci_enable,
3625 	.read_phy_reg		= ohci_read_phy_reg,
3626 	.update_phy_reg		= ohci_update_phy_reg,
3627 	.set_config_rom		= ohci_set_config_rom,
3628 	.send_request		= ohci_send_request,
3629 	.send_response		= ohci_send_response,
3630 	.cancel_packet		= ohci_cancel_packet,
3631 	.enable_phys_dma	= ohci_enable_phys_dma,
3632 	.read_csr		= ohci_read_csr,
3633 	.write_csr		= ohci_write_csr,
3634 
3635 	.allocate_iso_context	= ohci_allocate_iso_context,
3636 	.free_iso_context	= ohci_free_iso_context,
3637 	.set_iso_channels	= ohci_set_iso_channels,
3638 	.queue_iso		= ohci_queue_iso,
3639 	.flush_queue_iso	= ohci_flush_queue_iso,
3640 	.flush_iso_completions	= ohci_flush_iso_completions,
3641 	.start_iso		= ohci_start_iso,
3642 	.stop_iso		= ohci_stop_iso,
3643 };
3644 
3645 #ifdef CONFIG_PPC_PMAC
3646 static void pmac_ohci_on(struct pci_dev *dev)
3647 {
3648 	if (machine_is(powermac)) {
3649 		struct device_node *ofn = pci_device_to_OF_node(dev);
3650 
3651 		if (ofn) {
3652 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3653 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3654 		}
3655 	}
3656 }
3657 
3658 static void pmac_ohci_off(struct pci_dev *dev)
3659 {
3660 	if (machine_is(powermac)) {
3661 		struct device_node *ofn = pci_device_to_OF_node(dev);
3662 
3663 		if (ofn) {
3664 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3665 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3666 		}
3667 	}
3668 }
3669 #else
3670 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3671 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3672 #endif /* CONFIG_PPC_PMAC */
3673 
3674 static void release_ohci(struct device *dev, void *data)
3675 {
3676 	struct pci_dev *pdev = to_pci_dev(dev);
3677 	struct fw_ohci *ohci = pci_get_drvdata(pdev);
3678 
3679 	pmac_ohci_off(pdev);
3680 
3681 	ar_context_release(&ohci->ar_response_ctx);
3682 	ar_context_release(&ohci->ar_request_ctx);
3683 
3684 	dev_notice(dev, "removed fw-ohci device\n");
3685 }
3686 
3687 static int pci_probe(struct pci_dev *dev,
3688 			       const struct pci_device_id *ent)
3689 {
3690 	struct fw_ohci *ohci;
3691 	u32 bus_options, max_receive, link_speed, version;
3692 	u64 guid;
3693 	int i, flags, irq, err;
3694 	size_t size;
3695 
3696 	if (dev->vendor == PCI_VENDOR_ID_PINNACLE_SYSTEMS) {
3697 		dev_err(&dev->dev, "Pinnacle MovieBoard is not yet supported\n");
3698 		return -ENOSYS;
3699 	}
3700 
3701 	ohci = devres_alloc(release_ohci, sizeof(*ohci), GFP_KERNEL);
3702 	if (ohci == NULL)
3703 		return -ENOMEM;
3704 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3705 	pci_set_drvdata(dev, ohci);
3706 	pmac_ohci_on(dev);
3707 	devres_add(&dev->dev, ohci);
3708 
3709 	err = pcim_enable_device(dev);
3710 	if (err) {
3711 		dev_err(&dev->dev, "failed to enable OHCI hardware\n");
3712 		return err;
3713 	}
3714 
3715 	pci_set_master(dev);
3716 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3717 
3718 	spin_lock_init(&ohci->lock);
3719 	mutex_init(&ohci->phy_reg_mutex);
3720 
3721 	INIT_WORK(&ohci->bus_reset_work, bus_reset_work);
3722 
3723 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM) ||
3724 	    pci_resource_len(dev, 0) < OHCI1394_REGISTER_SIZE) {
3725 		ohci_err(ohci, "invalid MMIO resource\n");
3726 		return -ENXIO;
3727 	}
3728 
3729 	err = pcim_iomap_regions(dev, 1 << 0, ohci_driver_name);
3730 	if (err) {
3731 		ohci_err(ohci, "request and map MMIO resource unavailable\n");
3732 		return -ENXIO;
3733 	}
3734 	ohci->registers = pcim_iomap_table(dev)[0];
3735 
3736 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3737 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3738 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3739 		     ohci_quirks[i].device == dev->device) &&
3740 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3741 		     ohci_quirks[i].revision >= dev->revision)) {
3742 			ohci->quirks = ohci_quirks[i].flags;
3743 			break;
3744 		}
3745 	if (param_quirks)
3746 		ohci->quirks = param_quirks;
3747 
3748 	if (detect_vt630x_with_asm1083_on_amd_ryzen_machine(dev))
3749 		ohci->quirks |= QUIRK_REBOOT_BY_CYCLE_TIMER_READ;
3750 
3751 	/*
3752 	 * Because dma_alloc_coherent() allocates at least one page,
3753 	 * we save space by using a common buffer for the AR request/
3754 	 * response descriptors and the self IDs buffer.
3755 	 */
3756 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3757 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3758 	ohci->misc_buffer = dmam_alloc_coherent(&dev->dev, PAGE_SIZE, &ohci->misc_buffer_bus,
3759 						GFP_KERNEL);
3760 	if (!ohci->misc_buffer)
3761 		return -ENOMEM;
3762 
3763 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3764 			      OHCI1394_AsReqRcvContextControlSet);
3765 	if (err < 0)
3766 		return err;
3767 
3768 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3769 			      OHCI1394_AsRspRcvContextControlSet);
3770 	if (err < 0)
3771 		return err;
3772 
3773 	err = context_init(&ohci->at_request_ctx, ohci,
3774 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3775 	if (err < 0)
3776 		return err;
3777 
3778 	err = context_init(&ohci->at_response_ctx, ohci,
3779 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3780 	if (err < 0)
3781 		return err;
3782 
3783 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3784 	ohci->ir_context_channels = ~0ULL;
3785 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3786 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3787 	ohci->ir_context_mask = ohci->ir_context_support;
3788 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3789 	size = sizeof(struct iso_context) * ohci->n_ir;
3790 	ohci->ir_context_list = devm_kzalloc(&dev->dev, size, GFP_KERNEL);
3791 	if (!ohci->ir_context_list)
3792 		return -ENOMEM;
3793 
3794 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3795 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3796 	/* JMicron JMB38x often shows 0 at first read, just ignore it */
3797 	if (!ohci->it_context_support) {
3798 		ohci_notice(ohci, "overriding IsoXmitIntMask\n");
3799 		ohci->it_context_support = 0xf;
3800 	}
3801 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3802 	ohci->it_context_mask = ohci->it_context_support;
3803 	ohci->n_it = hweight32(ohci->it_context_mask);
3804 	size = sizeof(struct iso_context) * ohci->n_it;
3805 	ohci->it_context_list = devm_kzalloc(&dev->dev, size, GFP_KERNEL);
3806 	if (!ohci->it_context_list)
3807 		return -ENOMEM;
3808 
3809 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
3810 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3811 
3812 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3813 	max_receive = (bus_options >> 12) & 0xf;
3814 	link_speed = bus_options & 0x7;
3815 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3816 		reg_read(ohci, OHCI1394_GUIDLo);
3817 
3818 	flags = PCI_IRQ_INTX;
3819 	if (!(ohci->quirks & QUIRK_NO_MSI))
3820 		flags |= PCI_IRQ_MSI;
3821 	err = pci_alloc_irq_vectors(dev, 1, 1, flags);
3822 	if (err < 0)
3823 		return err;
3824 	irq = pci_irq_vector(dev, 0);
3825 	if (irq < 0) {
3826 		err = irq;
3827 		goto fail_msi;
3828 	}
3829 
3830 	err = request_threaded_irq(irq, irq_handler, NULL,
3831 				   pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED, ohci_driver_name,
3832 				   ohci);
3833 	if (err < 0) {
3834 		ohci_err(ohci, "failed to allocate interrupt %d\n", irq);
3835 		goto fail_msi;
3836 	}
3837 
3838 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid, ohci->n_it + ohci->n_ir);
3839 	if (err)
3840 		goto fail_irq;
3841 
3842 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3843 	ohci_notice(ohci,
3844 		    "added OHCI v%x.%x device as card %d, "
3845 		    "%d IR + %d IT contexts, quirks 0x%x%s\n",
3846 		    version >> 16, version & 0xff, ohci->card.index,
3847 		    ohci->n_ir, ohci->n_it, ohci->quirks,
3848 		    reg_read(ohci, OHCI1394_PhyUpperBound) ?
3849 			", physUB" : "");
3850 
3851 	return 0;
3852 
3853  fail_irq:
3854 	free_irq(irq, ohci);
3855  fail_msi:
3856 	pci_free_irq_vectors(dev);
3857 
3858 	return err;
3859 }
3860 
3861 static void pci_remove(struct pci_dev *dev)
3862 {
3863 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3864 	int irq;
3865 
3866 	/*
3867 	 * If the removal is happening from the suspend state, LPS won't be
3868 	 * enabled and host registers (eg., IntMaskClear) won't be accessible.
3869 	 */
3870 	if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) {
3871 		reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3872 		flush_writes(ohci);
3873 	}
3874 	cancel_work_sync(&ohci->bus_reset_work);
3875 	fw_core_remove_card(&ohci->card);
3876 
3877 	/*
3878 	 * FIXME: Fail all pending packets here, now that the upper
3879 	 * layers can't queue any more.
3880 	 */
3881 
3882 	software_reset(ohci);
3883 
3884 	irq = pci_irq_vector(dev, 0);
3885 	if (irq >= 0)
3886 		free_irq(irq, ohci);
3887 	pci_free_irq_vectors(dev);
3888 
3889 	dev_notice(&dev->dev, "removing fw-ohci device\n");
3890 }
3891 
3892 #ifdef CONFIG_PM
3893 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3894 {
3895 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3896 	int err;
3897 
3898 	software_reset(ohci);
3899 	err = pci_save_state(dev);
3900 	if (err) {
3901 		ohci_err(ohci, "pci_save_state failed\n");
3902 		return err;
3903 	}
3904 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3905 	if (err)
3906 		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
3907 	pmac_ohci_off(dev);
3908 
3909 	return 0;
3910 }
3911 
3912 static int pci_resume(struct pci_dev *dev)
3913 {
3914 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3915 	int err;
3916 
3917 	pmac_ohci_on(dev);
3918 	pci_set_power_state(dev, PCI_D0);
3919 	pci_restore_state(dev);
3920 	err = pci_enable_device(dev);
3921 	if (err) {
3922 		ohci_err(ohci, "pci_enable_device failed\n");
3923 		return err;
3924 	}
3925 
3926 	/* Some systems don't setup GUID register on resume from ram  */
3927 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3928 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3929 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3930 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3931 	}
3932 
3933 	err = ohci_enable(&ohci->card, NULL, 0);
3934 	if (err)
3935 		return err;
3936 
3937 	ohci_resume_iso_dma(ohci);
3938 
3939 	return 0;
3940 }
3941 #endif
3942 
3943 static const struct pci_device_id pci_table[] = {
3944 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3945 	{ }
3946 };
3947 
3948 MODULE_DEVICE_TABLE(pci, pci_table);
3949 
3950 static struct pci_driver fw_ohci_pci_driver = {
3951 	.name		= ohci_driver_name,
3952 	.id_table	= pci_table,
3953 	.probe		= pci_probe,
3954 	.remove		= pci_remove,
3955 #ifdef CONFIG_PM
3956 	.resume		= pci_resume,
3957 	.suspend	= pci_suspend,
3958 #endif
3959 };
3960 
3961 static int __init fw_ohci_init(void)
3962 {
3963 	selfid_workqueue = alloc_workqueue(KBUILD_MODNAME, WQ_MEM_RECLAIM, 0);
3964 	if (!selfid_workqueue)
3965 		return -ENOMEM;
3966 
3967 	return pci_register_driver(&fw_ohci_pci_driver);
3968 }
3969 
3970 static void __exit fw_ohci_cleanup(void)
3971 {
3972 	pci_unregister_driver(&fw_ohci_pci_driver);
3973 	destroy_workqueue(selfid_workqueue);
3974 }
3975 
3976 module_init(fw_ohci_init);
3977 module_exit(fw_ohci_cleanup);
3978 
3979 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3980 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3981 MODULE_LICENSE("GPL");
3982 
3983 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3984 MODULE_ALIAS("ohci1394");
3985