xref: /linux/drivers/firewire/ohci.c (revision 249ebf3f65f8530beb2cbfb91bff1d83ba88d23c)
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 
45 #define ohci_info(ohci, f, args...)	dev_info(ohci->card.device, f, ##args)
46 #define ohci_notice(ohci, f, args...)	dev_notice(ohci->card.device, f, ##args)
47 #define ohci_err(ohci, f, args...)	dev_err(ohci->card.device, f, ##args)
48 
49 #define DESCRIPTOR_OUTPUT_MORE		0
50 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
51 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
52 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
53 #define DESCRIPTOR_STATUS		(1 << 11)
54 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
55 #define DESCRIPTOR_PING			(1 << 7)
56 #define DESCRIPTOR_YY			(1 << 6)
57 #define DESCRIPTOR_NO_IRQ		(0 << 4)
58 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
59 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
60 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
61 #define DESCRIPTOR_WAIT			(3 << 0)
62 
63 #define DESCRIPTOR_CMD			(0xf << 12)
64 
65 struct descriptor {
66 	__le16 req_count;
67 	__le16 control;
68 	__le32 data_address;
69 	__le32 branch_address;
70 	__le16 res_count;
71 	__le16 transfer_status;
72 } __attribute__((aligned(16)));
73 
74 #define CONTROL_SET(regs)	(regs)
75 #define CONTROL_CLEAR(regs)	((regs) + 4)
76 #define COMMAND_PTR(regs)	((regs) + 12)
77 #define CONTEXT_MATCH(regs)	((regs) + 16)
78 
79 #define AR_BUFFER_SIZE	(32*1024)
80 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
81 /* we need at least two pages for proper list management */
82 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
83 
84 #define MAX_ASYNC_PAYLOAD	4096
85 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
86 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
87 
88 struct ar_context {
89 	struct fw_ohci *ohci;
90 	struct page *pages[AR_BUFFERS];
91 	void *buffer;
92 	struct descriptor *descriptors;
93 	dma_addr_t descriptors_bus;
94 	void *pointer;
95 	unsigned int last_buffer_index;
96 	u32 regs;
97 	struct tasklet_struct tasklet;
98 };
99 
100 struct context;
101 
102 typedef int (*descriptor_callback_t)(struct context *ctx,
103 				     struct descriptor *d,
104 				     struct descriptor *last);
105 
106 /*
107  * A buffer that contains a block of DMA-able coherent memory used for
108  * storing a portion of a DMA descriptor program.
109  */
110 struct descriptor_buffer {
111 	struct list_head list;
112 	dma_addr_t buffer_bus;
113 	size_t buffer_size;
114 	size_t used;
115 	struct descriptor buffer[];
116 };
117 
118 struct context {
119 	struct fw_ohci *ohci;
120 	u32 regs;
121 	int total_allocation;
122 	u32 current_bus;
123 	bool running;
124 	bool flushing;
125 
126 	/*
127 	 * List of page-sized buffers for storing DMA descriptors.
128 	 * Head of list contains buffers in use and tail of list contains
129 	 * free buffers.
130 	 */
131 	struct list_head buffer_list;
132 
133 	/*
134 	 * Pointer to a buffer inside buffer_list that contains the tail
135 	 * end of the current DMA program.
136 	 */
137 	struct descriptor_buffer *buffer_tail;
138 
139 	/*
140 	 * The descriptor containing the branch address of the first
141 	 * descriptor that has not yet been filled by the device.
142 	 */
143 	struct descriptor *last;
144 
145 	/*
146 	 * The last descriptor block in the DMA program. It contains the branch
147 	 * address that must be updated upon appending a new descriptor.
148 	 */
149 	struct descriptor *prev;
150 	int prev_z;
151 
152 	descriptor_callback_t callback;
153 
154 	struct tasklet_struct tasklet;
155 };
156 
157 #define IT_HEADER_SY(v)          ((v) <<  0)
158 #define IT_HEADER_TCODE(v)       ((v) <<  4)
159 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
160 #define IT_HEADER_TAG(v)         ((v) << 14)
161 #define IT_HEADER_SPEED(v)       ((v) << 16)
162 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
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 1024
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_TCODE_PHY_PACKET		0x0e
260 #define OHCI_VERSION_1_1		0x010010
261 
262 static char ohci_driver_name[] = KBUILD_MODNAME;
263 
264 #define PCI_VENDOR_ID_PINNACLE_SYSTEMS	0x11bd
265 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
266 #define PCI_DEVICE_ID_CREATIVE_SB1394	0x4001
267 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
268 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
269 #define PCI_DEVICE_ID_TI_TSB12LV26	0x8020
270 #define PCI_DEVICE_ID_TI_TSB82AA2	0x8025
271 #define PCI_DEVICE_ID_VIA_VT630X	0x3044
272 #define PCI_REV_ID_VIA_VT6306		0x46
273 #define PCI_DEVICE_ID_VIA_VT6315	0x3403
274 
275 #define QUIRK_CYCLE_TIMER		0x1
276 #define QUIRK_RESET_PACKET		0x2
277 #define QUIRK_BE_HEADERS		0x4
278 #define QUIRK_NO_1394A			0x8
279 #define QUIRK_NO_MSI			0x10
280 #define QUIRK_TI_SLLZ059		0x20
281 #define QUIRK_IR_WAKE			0x40
282 
283 // On PCI Express Root Complex in any type of AMD Ryzen machine, VIA VT6306/6307/6308 with Asmedia
284 // ASM1083/1085 brings an inconvenience that the read accesses to 'Isochronous Cycle Timer' register
285 // (at offset 0xf0 in PCI I/O space) often causes unexpected system reboot. The mechanism is not
286 // clear, since the read access to the other registers is enough safe; e.g. 'Node ID' register,
287 // while it is probable due to detection of any type of PCIe error.
288 #define QUIRK_REBOOT_BY_CYCLE_TIMER_READ	0x80000000
289 
290 #if IS_ENABLED(CONFIG_X86)
291 
292 static bool has_reboot_by_cycle_timer_read_quirk(const struct fw_ohci *ohci)
293 {
294 	return !!(ohci->quirks & QUIRK_REBOOT_BY_CYCLE_TIMER_READ);
295 }
296 
297 #define PCI_DEVICE_ID_ASMEDIA_ASM108X	0x1080
298 
299 static bool detect_vt630x_with_asm1083_on_amd_ryzen_machine(const struct pci_dev *pdev)
300 {
301 	const struct pci_dev *pcie_to_pci_bridge;
302 
303 	// Detect any type of AMD Ryzen machine.
304 	if (!static_cpu_has(X86_FEATURE_ZEN))
305 		return false;
306 
307 	// Detect VIA VT6306/6307/6308.
308 	if (pdev->vendor != PCI_VENDOR_ID_VIA)
309 		return false;
310 	if (pdev->device != PCI_DEVICE_ID_VIA_VT630X)
311 		return false;
312 
313 	// Detect Asmedia ASM1083/1085.
314 	pcie_to_pci_bridge = pdev->bus->self;
315 	if (pcie_to_pci_bridge->vendor != PCI_VENDOR_ID_ASMEDIA)
316 		return false;
317 	if (pcie_to_pci_bridge->device != PCI_DEVICE_ID_ASMEDIA_ASM108X)
318 		return false;
319 
320 	return true;
321 }
322 
323 #else
324 #define has_reboot_by_cycle_timer_read_quirk(ohci) false
325 #define detect_vt630x_with_asm1083_on_amd_ryzen_machine(pdev)	false
326 #endif
327 
328 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
329 static const struct {
330 	unsigned short vendor, device, revision, flags;
331 } ohci_quirks[] = {
332 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
333 		QUIRK_CYCLE_TIMER},
334 
335 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
336 		QUIRK_BE_HEADERS},
337 
338 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
339 		QUIRK_NO_MSI},
340 
341 	{PCI_VENDOR_ID_CREATIVE, PCI_DEVICE_ID_CREATIVE_SB1394, PCI_ANY_ID,
342 		QUIRK_RESET_PACKET},
343 
344 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
345 		QUIRK_NO_MSI},
346 
347 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
348 		QUIRK_CYCLE_TIMER},
349 
350 	{PCI_VENDOR_ID_O2, PCI_ANY_ID, PCI_ANY_ID,
351 		QUIRK_NO_MSI},
352 
353 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
354 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
355 
356 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
357 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
358 
359 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV26, PCI_ANY_ID,
360 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
361 
362 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB82AA2, PCI_ANY_ID,
363 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
364 
365 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
366 		QUIRK_RESET_PACKET},
367 
368 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT630X, PCI_REV_ID_VIA_VT6306,
369 		QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE},
370 
371 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, 0,
372 		QUIRK_CYCLE_TIMER /* FIXME: necessary? */ | QUIRK_NO_MSI},
373 
374 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, PCI_ANY_ID,
375 		QUIRK_NO_MSI},
376 
377 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
378 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
379 };
380 
381 /* This overrides anything that was found in ohci_quirks[]. */
382 static int param_quirks;
383 module_param_named(quirks, param_quirks, int, 0644);
384 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
385 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
386 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
387 	", AR/selfID endianness = "	__stringify(QUIRK_BE_HEADERS)
388 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
389 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
390 	", TI SLLZ059 erratum = "	__stringify(QUIRK_TI_SLLZ059)
391 	", IR wake unreliable = "	__stringify(QUIRK_IR_WAKE)
392 	")");
393 
394 #define OHCI_PARAM_DEBUG_AT_AR		1
395 #define OHCI_PARAM_DEBUG_SELFIDS	2
396 #define OHCI_PARAM_DEBUG_IRQS		4
397 
398 static int param_debug;
399 module_param_named(debug, param_debug, int, 0644);
400 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
401 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
402 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
403 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
404 	", or a combination, or all = -1)");
405 
406 static bool param_remote_dma;
407 module_param_named(remote_dma, param_remote_dma, bool, 0444);
408 MODULE_PARM_DESC(remote_dma, "Enable unfiltered remote DMA (default = N)");
409 
410 static void log_irqs(struct fw_ohci *ohci, u32 evt)
411 {
412 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_IRQS)))
413 		return;
414 
415 	ohci_notice(ohci, "IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
416 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
417 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
418 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
419 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
420 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
421 	    evt & OHCI1394_isochRx		? " IR"			: "",
422 	    evt & OHCI1394_isochTx		? " IT"			: "",
423 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
424 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
425 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
426 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
427 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
428 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
429 	    evt & OHCI1394_busReset		? " busReset"		: "",
430 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
431 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
432 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
433 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
434 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
435 		    OHCI1394_cycleInconsistent |
436 		    OHCI1394_regAccessFail | OHCI1394_busReset)
437 						? " ?"			: "");
438 }
439 
440 static const char *speed[] = {
441 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
442 };
443 static const char *power[] = {
444 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
445 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
446 };
447 static const char port[] = { '.', '-', 'p', 'c', };
448 
449 static char _p(u32 *s, int shift)
450 {
451 	return port[*s >> shift & 3];
452 }
453 
454 static void log_selfids(struct fw_ohci *ohci, int generation, int self_id_count)
455 {
456 	u32 *s;
457 
458 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
459 		return;
460 
461 	ohci_notice(ohci, "%d selfIDs, generation %d, local node ID %04x\n",
462 		    self_id_count, generation, ohci->node_id);
463 
464 	for (s = ohci->self_id_buffer; self_id_count--; ++s)
465 		if ((*s & 1 << 23) == 0)
466 			ohci_notice(ohci,
467 			    "selfID 0: %08x, phy %d [%c%c%c] %s gc=%d %s %s%s%s\n",
468 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
469 			    speed[*s >> 14 & 3], *s >> 16 & 63,
470 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
471 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
472 		else
473 			ohci_notice(ohci,
474 			    "selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
475 			    *s, *s >> 24 & 63,
476 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
477 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
478 }
479 
480 static const char *evts[] = {
481 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
482 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
483 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
484 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
485 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
486 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
487 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
488 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
489 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
490 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
491 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
492 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
493 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
494 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
495 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
496 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
497 	[0x20] = "pending/cancelled",
498 };
499 static const char *tcodes[] = {
500 	[0x0] = "QW req",		[0x1] = "BW req",
501 	[0x2] = "W resp",		[0x3] = "-reserved-",
502 	[0x4] = "QR req",		[0x5] = "BR req",
503 	[0x6] = "QR resp",		[0x7] = "BR resp",
504 	[0x8] = "cycle start",		[0x9] = "Lk req",
505 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
506 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
507 	[0xe] = "link internal",	[0xf] = "-reserved-",
508 };
509 
510 static void log_ar_at_event(struct fw_ohci *ohci,
511 			    char dir, int speed, u32 *header, int evt)
512 {
513 	int tcode = async_header_get_tcode(header);
514 	char specific[12];
515 
516 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
517 		return;
518 
519 	if (unlikely(evt >= ARRAY_SIZE(evts)))
520 		evt = 0x1f;
521 
522 	if (evt == OHCI1394_evt_bus_reset) {
523 		ohci_notice(ohci, "A%c evt_bus_reset, generation %d\n",
524 			    dir, (header[2] >> 16) & 0xff);
525 		return;
526 	}
527 
528 	switch (tcode) {
529 	case TCODE_WRITE_QUADLET_REQUEST:
530 	case TCODE_READ_QUADLET_RESPONSE:
531 	case TCODE_CYCLE_START:
532 		snprintf(specific, sizeof(specific), " = %08x",
533 			 be32_to_cpu((__force __be32)header[3]));
534 		break;
535 	case TCODE_WRITE_BLOCK_REQUEST:
536 	case TCODE_READ_BLOCK_REQUEST:
537 	case TCODE_READ_BLOCK_RESPONSE:
538 	case TCODE_LOCK_REQUEST:
539 	case TCODE_LOCK_RESPONSE:
540 		snprintf(specific, sizeof(specific), " %x,%x",
541 			 async_header_get_data_length(header),
542 			 async_header_get_extended_tcode(header));
543 		break;
544 	default:
545 		specific[0] = '\0';
546 	}
547 
548 	switch (tcode) {
549 	case TCODE_STREAM_DATA:
550 		ohci_notice(ohci, "A%c %s, %s\n",
551 			    dir, evts[evt], tcodes[tcode]);
552 		break;
553 	case 0xe:
554 		ohci_notice(ohci, "A%c %s, PHY %08x %08x\n",
555 			    dir, evts[evt], header[1], header[2]);
556 		break;
557 	case TCODE_WRITE_QUADLET_REQUEST:
558 	case TCODE_WRITE_BLOCK_REQUEST:
559 	case TCODE_READ_QUADLET_REQUEST:
560 	case TCODE_READ_BLOCK_REQUEST:
561 	case TCODE_LOCK_REQUEST:
562 		ohci_notice(ohci,
563 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s, %012llx%s\n",
564 			    dir, speed, async_header_get_tlabel(header),
565 			    async_header_get_source(header), async_header_get_destination(header),
566 			    evts[evt], tcodes[tcode], async_header_get_offset(header), specific);
567 		break;
568 	default:
569 		ohci_notice(ohci,
570 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s%s\n",
571 			    dir, speed, async_header_get_tlabel(header),
572 			    async_header_get_source(header), async_header_get_destination(header),
573 			    evts[evt], tcodes[tcode], specific);
574 	}
575 }
576 
577 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
578 {
579 	writel(data, ohci->registers + offset);
580 }
581 
582 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
583 {
584 	return readl(ohci->registers + offset);
585 }
586 
587 static inline void flush_writes(const struct fw_ohci *ohci)
588 {
589 	/* Do a dummy read to flush writes. */
590 	reg_read(ohci, OHCI1394_Version);
591 }
592 
593 /*
594  * Beware!  read_phy_reg(), write_phy_reg(), update_phy_reg(), and
595  * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
596  * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
597  * directly.  Exceptions are intrinsically serialized contexts like pci_probe.
598  */
599 static int read_phy_reg(struct fw_ohci *ohci, int addr)
600 {
601 	u32 val;
602 	int i;
603 
604 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
605 	for (i = 0; i < 3 + 100; i++) {
606 		val = reg_read(ohci, OHCI1394_PhyControl);
607 		if (!~val)
608 			return -ENODEV; /* Card was ejected. */
609 
610 		if (val & OHCI1394_PhyControl_ReadDone)
611 			return OHCI1394_PhyControl_ReadData(val);
612 
613 		/*
614 		 * Try a few times without waiting.  Sleeping is necessary
615 		 * only when the link/PHY interface is busy.
616 		 */
617 		if (i >= 3)
618 			msleep(1);
619 	}
620 	ohci_err(ohci, "failed to read phy reg %d\n", addr);
621 	dump_stack();
622 
623 	return -EBUSY;
624 }
625 
626 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
627 {
628 	int i;
629 
630 	reg_write(ohci, OHCI1394_PhyControl,
631 		  OHCI1394_PhyControl_Write(addr, val));
632 	for (i = 0; i < 3 + 100; i++) {
633 		val = reg_read(ohci, OHCI1394_PhyControl);
634 		if (!~val)
635 			return -ENODEV; /* Card was ejected. */
636 
637 		if (!(val & OHCI1394_PhyControl_WritePending))
638 			return 0;
639 
640 		if (i >= 3)
641 			msleep(1);
642 	}
643 	ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
644 	dump_stack();
645 
646 	return -EBUSY;
647 }
648 
649 static int update_phy_reg(struct fw_ohci *ohci, int addr,
650 			  int clear_bits, int set_bits)
651 {
652 	int ret = read_phy_reg(ohci, addr);
653 	if (ret < 0)
654 		return ret;
655 
656 	/*
657 	 * The interrupt status bits are cleared by writing a one bit.
658 	 * Avoid clearing them unless explicitly requested in set_bits.
659 	 */
660 	if (addr == 5)
661 		clear_bits |= PHY_INT_STATUS_BITS;
662 
663 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
664 }
665 
666 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
667 {
668 	int ret;
669 
670 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
671 	if (ret < 0)
672 		return ret;
673 
674 	return read_phy_reg(ohci, addr);
675 }
676 
677 static int ohci_read_phy_reg(struct fw_card *card, int addr)
678 {
679 	struct fw_ohci *ohci = fw_ohci(card);
680 	int ret;
681 
682 	mutex_lock(&ohci->phy_reg_mutex);
683 	ret = read_phy_reg(ohci, addr);
684 	mutex_unlock(&ohci->phy_reg_mutex);
685 
686 	return ret;
687 }
688 
689 static int ohci_update_phy_reg(struct fw_card *card, int addr,
690 			       int clear_bits, int set_bits)
691 {
692 	struct fw_ohci *ohci = fw_ohci(card);
693 	int ret;
694 
695 	mutex_lock(&ohci->phy_reg_mutex);
696 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
697 	mutex_unlock(&ohci->phy_reg_mutex);
698 
699 	return ret;
700 }
701 
702 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
703 {
704 	return page_private(ctx->pages[i]);
705 }
706 
707 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
708 {
709 	struct descriptor *d;
710 
711 	d = &ctx->descriptors[index];
712 	d->branch_address  &= cpu_to_le32(~0xf);
713 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
714 	d->transfer_status =  0;
715 
716 	wmb(); /* finish init of new descriptors before branch_address update */
717 	d = &ctx->descriptors[ctx->last_buffer_index];
718 	d->branch_address  |= cpu_to_le32(1);
719 
720 	ctx->last_buffer_index = index;
721 
722 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
723 }
724 
725 static void ar_context_release(struct ar_context *ctx)
726 {
727 	struct device *dev = ctx->ohci->card.device;
728 	unsigned int i;
729 
730 	if (!ctx->buffer)
731 		return;
732 
733 	vunmap(ctx->buffer);
734 
735 	for (i = 0; i < AR_BUFFERS; i++) {
736 		if (ctx->pages[i])
737 			dma_free_pages(dev, PAGE_SIZE, ctx->pages[i],
738 				       ar_buffer_bus(ctx, i), DMA_FROM_DEVICE);
739 	}
740 }
741 
742 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
743 {
744 	struct fw_ohci *ohci = ctx->ohci;
745 
746 	if (reg_read(ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
747 		reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
748 		flush_writes(ohci);
749 
750 		ohci_err(ohci, "AR error: %s; DMA stopped\n", error_msg);
751 	}
752 	/* FIXME: restart? */
753 }
754 
755 static inline unsigned int ar_next_buffer_index(unsigned int index)
756 {
757 	return (index + 1) % AR_BUFFERS;
758 }
759 
760 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
761 {
762 	return ar_next_buffer_index(ctx->last_buffer_index);
763 }
764 
765 /*
766  * We search for the buffer that contains the last AR packet DMA data written
767  * by the controller.
768  */
769 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
770 						 unsigned int *buffer_offset)
771 {
772 	unsigned int i, next_i, last = ctx->last_buffer_index;
773 	__le16 res_count, next_res_count;
774 
775 	i = ar_first_buffer_index(ctx);
776 	res_count = READ_ONCE(ctx->descriptors[i].res_count);
777 
778 	/* A buffer that is not yet completely filled must be the last one. */
779 	while (i != last && res_count == 0) {
780 
781 		/* Peek at the next descriptor. */
782 		next_i = ar_next_buffer_index(i);
783 		rmb(); /* read descriptors in order */
784 		next_res_count = READ_ONCE(ctx->descriptors[next_i].res_count);
785 		/*
786 		 * If the next descriptor is still empty, we must stop at this
787 		 * descriptor.
788 		 */
789 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
790 			/*
791 			 * The exception is when the DMA data for one packet is
792 			 * split over three buffers; in this case, the middle
793 			 * buffer's descriptor might be never updated by the
794 			 * controller and look still empty, and we have to peek
795 			 * at the third one.
796 			 */
797 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
798 				next_i = ar_next_buffer_index(next_i);
799 				rmb();
800 				next_res_count = READ_ONCE(ctx->descriptors[next_i].res_count);
801 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
802 					goto next_buffer_is_active;
803 			}
804 
805 			break;
806 		}
807 
808 next_buffer_is_active:
809 		i = next_i;
810 		res_count = next_res_count;
811 	}
812 
813 	rmb(); /* read res_count before the DMA data */
814 
815 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
816 	if (*buffer_offset > PAGE_SIZE) {
817 		*buffer_offset = 0;
818 		ar_context_abort(ctx, "corrupted descriptor");
819 	}
820 
821 	return i;
822 }
823 
824 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
825 				    unsigned int end_buffer_index,
826 				    unsigned int end_buffer_offset)
827 {
828 	unsigned int i;
829 
830 	i = ar_first_buffer_index(ctx);
831 	while (i != end_buffer_index) {
832 		dma_sync_single_for_cpu(ctx->ohci->card.device,
833 					ar_buffer_bus(ctx, i),
834 					PAGE_SIZE, DMA_FROM_DEVICE);
835 		i = ar_next_buffer_index(i);
836 	}
837 	if (end_buffer_offset > 0)
838 		dma_sync_single_for_cpu(ctx->ohci->card.device,
839 					ar_buffer_bus(ctx, i),
840 					end_buffer_offset, DMA_FROM_DEVICE);
841 }
842 
843 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
844 #define cond_le32_to_cpu(v) \
845 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
846 #else
847 #define cond_le32_to_cpu(v) le32_to_cpu(v)
848 #endif
849 
850 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
851 {
852 	struct fw_ohci *ohci = ctx->ohci;
853 	struct fw_packet p;
854 	u32 status, length, tcode;
855 	int evt;
856 
857 	p.header[0] = cond_le32_to_cpu(buffer[0]);
858 	p.header[1] = cond_le32_to_cpu(buffer[1]);
859 	p.header[2] = cond_le32_to_cpu(buffer[2]);
860 
861 	tcode = async_header_get_tcode(p.header);
862 	switch (tcode) {
863 	case TCODE_WRITE_QUADLET_REQUEST:
864 	case TCODE_READ_QUADLET_RESPONSE:
865 		p.header[3] = (__force __u32) buffer[3];
866 		p.header_length = 16;
867 		p.payload_length = 0;
868 		break;
869 
870 	case TCODE_READ_BLOCK_REQUEST :
871 		p.header[3] = cond_le32_to_cpu(buffer[3]);
872 		p.header_length = 16;
873 		p.payload_length = 0;
874 		break;
875 
876 	case TCODE_WRITE_BLOCK_REQUEST:
877 	case TCODE_READ_BLOCK_RESPONSE:
878 	case TCODE_LOCK_REQUEST:
879 	case TCODE_LOCK_RESPONSE:
880 		p.header[3] = cond_le32_to_cpu(buffer[3]);
881 		p.header_length = 16;
882 		p.payload_length = async_header_get_data_length(p.header);
883 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
884 			ar_context_abort(ctx, "invalid packet length");
885 			return NULL;
886 		}
887 		break;
888 
889 	case TCODE_WRITE_RESPONSE:
890 	case TCODE_READ_QUADLET_REQUEST:
891 	case OHCI_TCODE_PHY_PACKET:
892 		p.header_length = 12;
893 		p.payload_length = 0;
894 		break;
895 
896 	default:
897 		ar_context_abort(ctx, "invalid tcode");
898 		return NULL;
899 	}
900 
901 	p.payload = (void *) buffer + p.header_length;
902 
903 	/* FIXME: What to do about evt_* errors? */
904 	length = (p.header_length + p.payload_length + 3) / 4;
905 	status = cond_le32_to_cpu(buffer[length]);
906 	evt    = (status >> 16) & 0x1f;
907 
908 	p.ack        = evt - 16;
909 	p.speed      = (status >> 21) & 0x7;
910 	p.timestamp  = status & 0xffff;
911 	p.generation = ohci->request_generation;
912 
913 	log_ar_at_event(ohci, 'R', p.speed, p.header, evt);
914 
915 	/*
916 	 * Several controllers, notably from NEC and VIA, forget to
917 	 * write ack_complete status at PHY packet reception.
918 	 */
919 	if (evt == OHCI1394_evt_no_status && tcode == OHCI1394_phy_tcode)
920 		p.ack = ACK_COMPLETE;
921 
922 	/*
923 	 * The OHCI bus reset handler synthesizes a PHY packet with
924 	 * the new generation number when a bus reset happens (see
925 	 * section 8.4.2.3).  This helps us determine when a request
926 	 * was received and make sure we send the response in the same
927 	 * generation.  We only need this for requests; for responses
928 	 * we use the unique tlabel for finding the matching
929 	 * request.
930 	 *
931 	 * Alas some chips sometimes emit bus reset packets with a
932 	 * wrong generation.  We set the correct generation for these
933 	 * at a slightly incorrect time (in bus_reset_work).
934 	 */
935 	if (evt == OHCI1394_evt_bus_reset) {
936 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
937 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
938 	} else if (ctx == &ohci->ar_request_ctx) {
939 		fw_core_handle_request(&ohci->card, &p);
940 	} else {
941 		fw_core_handle_response(&ohci->card, &p);
942 	}
943 
944 	return buffer + length + 1;
945 }
946 
947 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
948 {
949 	void *next;
950 
951 	while (p < end) {
952 		next = handle_ar_packet(ctx, p);
953 		if (!next)
954 			return p;
955 		p = next;
956 	}
957 
958 	return p;
959 }
960 
961 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
962 {
963 	unsigned int i;
964 
965 	i = ar_first_buffer_index(ctx);
966 	while (i != end_buffer) {
967 		dma_sync_single_for_device(ctx->ohci->card.device,
968 					   ar_buffer_bus(ctx, i),
969 					   PAGE_SIZE, DMA_FROM_DEVICE);
970 		ar_context_link_page(ctx, i);
971 		i = ar_next_buffer_index(i);
972 	}
973 }
974 
975 static void ar_context_tasklet(unsigned long data)
976 {
977 	struct ar_context *ctx = (struct ar_context *)data;
978 	unsigned int end_buffer_index, end_buffer_offset;
979 	void *p, *end;
980 
981 	p = ctx->pointer;
982 	if (!p)
983 		return;
984 
985 	end_buffer_index = ar_search_last_active_buffer(ctx,
986 							&end_buffer_offset);
987 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
988 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
989 
990 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
991 		/*
992 		 * The filled part of the overall buffer wraps around; handle
993 		 * all packets up to the buffer end here.  If the last packet
994 		 * wraps around, its tail will be visible after the buffer end
995 		 * because the buffer start pages are mapped there again.
996 		 */
997 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
998 		p = handle_ar_packets(ctx, p, buffer_end);
999 		if (p < buffer_end)
1000 			goto error;
1001 		/* adjust p to point back into the actual buffer */
1002 		p -= AR_BUFFERS * PAGE_SIZE;
1003 	}
1004 
1005 	p = handle_ar_packets(ctx, p, end);
1006 	if (p != end) {
1007 		if (p > end)
1008 			ar_context_abort(ctx, "inconsistent descriptor");
1009 		goto error;
1010 	}
1011 
1012 	ctx->pointer = p;
1013 	ar_recycle_buffers(ctx, end_buffer_index);
1014 
1015 	return;
1016 
1017 error:
1018 	ctx->pointer = NULL;
1019 }
1020 
1021 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
1022 			   unsigned int descriptors_offset, u32 regs)
1023 {
1024 	struct device *dev = ohci->card.device;
1025 	unsigned int i;
1026 	dma_addr_t dma_addr;
1027 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
1028 	struct descriptor *d;
1029 
1030 	ctx->regs        = regs;
1031 	ctx->ohci        = ohci;
1032 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
1033 
1034 	for (i = 0; i < AR_BUFFERS; i++) {
1035 		ctx->pages[i] = dma_alloc_pages(dev, PAGE_SIZE, &dma_addr,
1036 						DMA_FROM_DEVICE, GFP_KERNEL);
1037 		if (!ctx->pages[i])
1038 			goto out_of_memory;
1039 		set_page_private(ctx->pages[i], dma_addr);
1040 		dma_sync_single_for_device(dev, dma_addr, PAGE_SIZE,
1041 					   DMA_FROM_DEVICE);
1042 	}
1043 
1044 	for (i = 0; i < AR_BUFFERS; i++)
1045 		pages[i]              = ctx->pages[i];
1046 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
1047 		pages[AR_BUFFERS + i] = ctx->pages[i];
1048 	ctx->buffer = vmap(pages, ARRAY_SIZE(pages), VM_MAP, PAGE_KERNEL);
1049 	if (!ctx->buffer)
1050 		goto out_of_memory;
1051 
1052 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
1053 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
1054 
1055 	for (i = 0; i < AR_BUFFERS; i++) {
1056 		d = &ctx->descriptors[i];
1057 		d->req_count      = cpu_to_le16(PAGE_SIZE);
1058 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
1059 						DESCRIPTOR_STATUS |
1060 						DESCRIPTOR_BRANCH_ALWAYS);
1061 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
1062 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
1063 			ar_next_buffer_index(i) * sizeof(struct descriptor));
1064 	}
1065 
1066 	return 0;
1067 
1068 out_of_memory:
1069 	ar_context_release(ctx);
1070 
1071 	return -ENOMEM;
1072 }
1073 
1074 static void ar_context_run(struct ar_context *ctx)
1075 {
1076 	unsigned int i;
1077 
1078 	for (i = 0; i < AR_BUFFERS; i++)
1079 		ar_context_link_page(ctx, i);
1080 
1081 	ctx->pointer = ctx->buffer;
1082 
1083 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1084 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1085 }
1086 
1087 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1088 {
1089 	__le16 branch;
1090 
1091 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1092 
1093 	/* figure out which descriptor the branch address goes in */
1094 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1095 		return d;
1096 	else
1097 		return d + z - 1;
1098 }
1099 
1100 static void context_tasklet(unsigned long data)
1101 {
1102 	struct context *ctx = (struct context *) data;
1103 	struct descriptor *d, *last;
1104 	u32 address;
1105 	int z;
1106 	struct descriptor_buffer *desc;
1107 
1108 	desc = list_entry(ctx->buffer_list.next,
1109 			struct descriptor_buffer, list);
1110 	last = ctx->last;
1111 	while (last->branch_address != 0) {
1112 		struct descriptor_buffer *old_desc = desc;
1113 		address = le32_to_cpu(last->branch_address);
1114 		z = address & 0xf;
1115 		address &= ~0xf;
1116 		ctx->current_bus = address;
1117 
1118 		/* If the branch address points to a buffer outside of the
1119 		 * current buffer, advance to the next buffer. */
1120 		if (address < desc->buffer_bus ||
1121 				address >= desc->buffer_bus + desc->used)
1122 			desc = list_entry(desc->list.next,
1123 					struct descriptor_buffer, list);
1124 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1125 		last = find_branch_descriptor(d, z);
1126 
1127 		if (!ctx->callback(ctx, d, last))
1128 			break;
1129 
1130 		if (old_desc != desc) {
1131 			/* If we've advanced to the next buffer, move the
1132 			 * previous buffer to the free list. */
1133 			unsigned long flags;
1134 			old_desc->used = 0;
1135 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1136 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1137 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1138 		}
1139 		ctx->last = last;
1140 	}
1141 }
1142 
1143 /*
1144  * Allocate a new buffer and add it to the list of free buffers for this
1145  * context.  Must be called with ohci->lock held.
1146  */
1147 static int context_add_buffer(struct context *ctx)
1148 {
1149 	struct descriptor_buffer *desc;
1150 	dma_addr_t bus_addr;
1151 	int offset;
1152 
1153 	/*
1154 	 * 16MB of descriptors should be far more than enough for any DMA
1155 	 * program.  This will catch run-away userspace or DoS attacks.
1156 	 */
1157 	if (ctx->total_allocation >= 16*1024*1024)
1158 		return -ENOMEM;
1159 
1160 	desc = dmam_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE, &bus_addr, GFP_ATOMIC);
1161 	if (!desc)
1162 		return -ENOMEM;
1163 
1164 	offset = (void *)&desc->buffer - (void *)desc;
1165 	/*
1166 	 * Some controllers, like JMicron ones, always issue 0x20-byte DMA reads
1167 	 * for descriptors, even 0x10-byte ones. This can cause page faults when
1168 	 * an IOMMU is in use and the oversized read crosses a page boundary.
1169 	 * Work around this by always leaving at least 0x10 bytes of padding.
1170 	 */
1171 	desc->buffer_size = PAGE_SIZE - offset - 0x10;
1172 	desc->buffer_bus = bus_addr + offset;
1173 	desc->used = 0;
1174 
1175 	list_add_tail(&desc->list, &ctx->buffer_list);
1176 	ctx->total_allocation += PAGE_SIZE;
1177 
1178 	return 0;
1179 }
1180 
1181 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1182 			u32 regs, descriptor_callback_t callback)
1183 {
1184 	ctx->ohci = ohci;
1185 	ctx->regs = regs;
1186 	ctx->total_allocation = 0;
1187 
1188 	INIT_LIST_HEAD(&ctx->buffer_list);
1189 	if (context_add_buffer(ctx) < 0)
1190 		return -ENOMEM;
1191 
1192 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1193 			struct descriptor_buffer, list);
1194 
1195 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1196 	ctx->callback = callback;
1197 
1198 	/*
1199 	 * We put a dummy descriptor in the buffer that has a NULL
1200 	 * branch address and looks like it's been sent.  That way we
1201 	 * have a descriptor to append DMA programs to.
1202 	 */
1203 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1204 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1205 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1206 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1207 	ctx->last = ctx->buffer_tail->buffer;
1208 	ctx->prev = ctx->buffer_tail->buffer;
1209 	ctx->prev_z = 1;
1210 
1211 	return 0;
1212 }
1213 
1214 static void context_release(struct context *ctx)
1215 {
1216 	struct fw_card *card = &ctx->ohci->card;
1217 	struct descriptor_buffer *desc, *tmp;
1218 
1219 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list) {
1220 		dmam_free_coherent(card->device, PAGE_SIZE, desc,
1221 				   desc->buffer_bus - ((void *)&desc->buffer - (void *)desc));
1222 	}
1223 }
1224 
1225 /* Must be called with ohci->lock held */
1226 static struct descriptor *context_get_descriptors(struct context *ctx,
1227 						  int z, dma_addr_t *d_bus)
1228 {
1229 	struct descriptor *d = NULL;
1230 	struct descriptor_buffer *desc = ctx->buffer_tail;
1231 
1232 	if (z * sizeof(*d) > desc->buffer_size)
1233 		return NULL;
1234 
1235 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1236 		/* No room for the descriptor in this buffer, so advance to the
1237 		 * next one. */
1238 
1239 		if (desc->list.next == &ctx->buffer_list) {
1240 			/* If there is no free buffer next in the list,
1241 			 * allocate one. */
1242 			if (context_add_buffer(ctx) < 0)
1243 				return NULL;
1244 		}
1245 		desc = list_entry(desc->list.next,
1246 				struct descriptor_buffer, list);
1247 		ctx->buffer_tail = desc;
1248 	}
1249 
1250 	d = desc->buffer + desc->used / sizeof(*d);
1251 	memset(d, 0, z * sizeof(*d));
1252 	*d_bus = desc->buffer_bus + desc->used;
1253 
1254 	return d;
1255 }
1256 
1257 static void context_run(struct context *ctx, u32 extra)
1258 {
1259 	struct fw_ohci *ohci = ctx->ohci;
1260 
1261 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1262 		  le32_to_cpu(ctx->last->branch_address));
1263 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1264 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1265 	ctx->running = true;
1266 	flush_writes(ohci);
1267 }
1268 
1269 static void context_append(struct context *ctx,
1270 			   struct descriptor *d, int z, int extra)
1271 {
1272 	dma_addr_t d_bus;
1273 	struct descriptor_buffer *desc = ctx->buffer_tail;
1274 	struct descriptor *d_branch;
1275 
1276 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1277 
1278 	desc->used += (z + extra) * sizeof(*d);
1279 
1280 	wmb(); /* finish init of new descriptors before branch_address update */
1281 
1282 	d_branch = find_branch_descriptor(ctx->prev, ctx->prev_z);
1283 	d_branch->branch_address = cpu_to_le32(d_bus | z);
1284 
1285 	/*
1286 	 * VT6306 incorrectly checks only the single descriptor at the
1287 	 * CommandPtr when the wake bit is written, so if it's a
1288 	 * multi-descriptor block starting with an INPUT_MORE, put a copy of
1289 	 * the branch address in the first descriptor.
1290 	 *
1291 	 * Not doing this for transmit contexts since not sure how it interacts
1292 	 * with skip addresses.
1293 	 */
1294 	if (unlikely(ctx->ohci->quirks & QUIRK_IR_WAKE) &&
1295 	    d_branch != ctx->prev &&
1296 	    (ctx->prev->control & cpu_to_le16(DESCRIPTOR_CMD)) ==
1297 	     cpu_to_le16(DESCRIPTOR_INPUT_MORE)) {
1298 		ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1299 	}
1300 
1301 	ctx->prev = d;
1302 	ctx->prev_z = z;
1303 }
1304 
1305 static void context_stop(struct context *ctx)
1306 {
1307 	struct fw_ohci *ohci = ctx->ohci;
1308 	u32 reg;
1309 	int i;
1310 
1311 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1312 	ctx->running = false;
1313 
1314 	for (i = 0; i < 1000; i++) {
1315 		reg = reg_read(ohci, CONTROL_SET(ctx->regs));
1316 		if ((reg & CONTEXT_ACTIVE) == 0)
1317 			return;
1318 
1319 		if (i)
1320 			udelay(10);
1321 	}
1322 	ohci_err(ohci, "DMA context still active (0x%08x)\n", reg);
1323 }
1324 
1325 struct driver_data {
1326 	u8 inline_data[8];
1327 	struct fw_packet *packet;
1328 };
1329 
1330 /*
1331  * This function apppends a packet to the DMA queue for transmission.
1332  * Must always be called with the ochi->lock held to ensure proper
1333  * generation handling and locking around packet queue manipulation.
1334  */
1335 static int at_context_queue_packet(struct context *ctx,
1336 				   struct fw_packet *packet)
1337 {
1338 	struct fw_ohci *ohci = ctx->ohci;
1339 	dma_addr_t d_bus, payload_bus;
1340 	struct driver_data *driver_data;
1341 	struct descriptor *d, *last;
1342 	__le32 *header;
1343 	int z, tcode;
1344 
1345 	d = context_get_descriptors(ctx, 4, &d_bus);
1346 	if (d == NULL) {
1347 		packet->ack = RCODE_SEND_ERROR;
1348 		return -1;
1349 	}
1350 
1351 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1352 	d[0].res_count = cpu_to_le16(packet->timestamp);
1353 
1354 	/*
1355 	 * The DMA format for asynchronous link packets is different
1356 	 * from the IEEE1394 layout, so shift the fields around
1357 	 * accordingly.
1358 	 */
1359 
1360 	tcode = async_header_get_tcode(packet->header);
1361 	header = (__le32 *) &d[1];
1362 	switch (tcode) {
1363 	case TCODE_WRITE_QUADLET_REQUEST:
1364 	case TCODE_WRITE_BLOCK_REQUEST:
1365 	case TCODE_WRITE_RESPONSE:
1366 	case TCODE_READ_QUADLET_REQUEST:
1367 	case TCODE_READ_BLOCK_REQUEST:
1368 	case TCODE_READ_QUADLET_RESPONSE:
1369 	case TCODE_READ_BLOCK_RESPONSE:
1370 	case TCODE_LOCK_REQUEST:
1371 	case TCODE_LOCK_RESPONSE:
1372 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1373 					(packet->speed << 16));
1374 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1375 					(packet->header[0] & 0xffff0000));
1376 		header[2] = cpu_to_le32(packet->header[2]);
1377 
1378 		if (tcode_is_block_packet(tcode))
1379 			header[3] = cpu_to_le32(packet->header[3]);
1380 		else
1381 			header[3] = (__force __le32) packet->header[3];
1382 
1383 		d[0].req_count = cpu_to_le16(packet->header_length);
1384 		break;
1385 
1386 	case TCODE_LINK_INTERNAL:
1387 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1388 					(packet->speed << 16));
1389 		header[1] = cpu_to_le32(packet->header[1]);
1390 		header[2] = cpu_to_le32(packet->header[2]);
1391 		d[0].req_count = cpu_to_le16(12);
1392 
1393 		if (is_ping_packet(&packet->header[1]))
1394 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1395 		break;
1396 
1397 	case TCODE_STREAM_DATA:
1398 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1399 					(packet->speed << 16));
1400 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1401 		d[0].req_count = cpu_to_le16(8);
1402 		break;
1403 
1404 	default:
1405 		/* BUG(); */
1406 		packet->ack = RCODE_SEND_ERROR;
1407 		return -1;
1408 	}
1409 
1410 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1411 	driver_data = (struct driver_data *) &d[3];
1412 	driver_data->packet = packet;
1413 	packet->driver_data = driver_data;
1414 
1415 	if (packet->payload_length > 0) {
1416 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1417 			payload_bus = dma_map_single(ohci->card.device,
1418 						     packet->payload,
1419 						     packet->payload_length,
1420 						     DMA_TO_DEVICE);
1421 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1422 				packet->ack = RCODE_SEND_ERROR;
1423 				return -1;
1424 			}
1425 			packet->payload_bus	= payload_bus;
1426 			packet->payload_mapped	= true;
1427 		} else {
1428 			memcpy(driver_data->inline_data, packet->payload,
1429 			       packet->payload_length);
1430 			payload_bus = d_bus + 3 * sizeof(*d);
1431 		}
1432 
1433 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1434 		d[2].data_address = cpu_to_le32(payload_bus);
1435 		last = &d[2];
1436 		z = 3;
1437 	} else {
1438 		last = &d[0];
1439 		z = 2;
1440 	}
1441 
1442 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1443 				     DESCRIPTOR_IRQ_ALWAYS |
1444 				     DESCRIPTOR_BRANCH_ALWAYS);
1445 
1446 	/* FIXME: Document how the locking works. */
1447 	if (ohci->generation != packet->generation) {
1448 		if (packet->payload_mapped)
1449 			dma_unmap_single(ohci->card.device, payload_bus,
1450 					 packet->payload_length, DMA_TO_DEVICE);
1451 		packet->ack = RCODE_GENERATION;
1452 		return -1;
1453 	}
1454 
1455 	context_append(ctx, d, z, 4 - z);
1456 
1457 	if (ctx->running)
1458 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1459 	else
1460 		context_run(ctx, 0);
1461 
1462 	return 0;
1463 }
1464 
1465 static void at_context_flush(struct context *ctx)
1466 {
1467 	tasklet_disable(&ctx->tasklet);
1468 
1469 	ctx->flushing = true;
1470 	context_tasklet((unsigned long)ctx);
1471 	ctx->flushing = false;
1472 
1473 	tasklet_enable(&ctx->tasklet);
1474 }
1475 
1476 static int handle_at_packet(struct context *context,
1477 			    struct descriptor *d,
1478 			    struct descriptor *last)
1479 {
1480 	struct driver_data *driver_data;
1481 	struct fw_packet *packet;
1482 	struct fw_ohci *ohci = context->ohci;
1483 	int evt;
1484 
1485 	if (last->transfer_status == 0 && !context->flushing)
1486 		/* This descriptor isn't done yet, stop iteration. */
1487 		return 0;
1488 
1489 	driver_data = (struct driver_data *) &d[3];
1490 	packet = driver_data->packet;
1491 	if (packet == NULL)
1492 		/* This packet was cancelled, just continue. */
1493 		return 1;
1494 
1495 	if (packet->payload_mapped)
1496 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1497 				 packet->payload_length, DMA_TO_DEVICE);
1498 
1499 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1500 	packet->timestamp = le16_to_cpu(last->res_count);
1501 
1502 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, evt);
1503 
1504 	switch (evt) {
1505 	case OHCI1394_evt_timeout:
1506 		/* Async response transmit timed out. */
1507 		packet->ack = RCODE_CANCELLED;
1508 		break;
1509 
1510 	case OHCI1394_evt_flushed:
1511 		/*
1512 		 * The packet was flushed should give same error as
1513 		 * when we try to use a stale generation count.
1514 		 */
1515 		packet->ack = RCODE_GENERATION;
1516 		break;
1517 
1518 	case OHCI1394_evt_missing_ack:
1519 		if (context->flushing)
1520 			packet->ack = RCODE_GENERATION;
1521 		else {
1522 			/*
1523 			 * Using a valid (current) generation count, but the
1524 			 * node is not on the bus or not sending acks.
1525 			 */
1526 			packet->ack = RCODE_NO_ACK;
1527 		}
1528 		break;
1529 
1530 	case ACK_COMPLETE + 0x10:
1531 	case ACK_PENDING + 0x10:
1532 	case ACK_BUSY_X + 0x10:
1533 	case ACK_BUSY_A + 0x10:
1534 	case ACK_BUSY_B + 0x10:
1535 	case ACK_DATA_ERROR + 0x10:
1536 	case ACK_TYPE_ERROR + 0x10:
1537 		packet->ack = evt - 0x10;
1538 		break;
1539 
1540 	case OHCI1394_evt_no_status:
1541 		if (context->flushing) {
1542 			packet->ack = RCODE_GENERATION;
1543 			break;
1544 		}
1545 		fallthrough;
1546 
1547 	default:
1548 		packet->ack = RCODE_SEND_ERROR;
1549 		break;
1550 	}
1551 
1552 	packet->callback(packet, &ohci->card, packet->ack);
1553 
1554 	return 1;
1555 }
1556 
1557 static u32 get_cycle_time(struct fw_ohci *ohci);
1558 
1559 static void handle_local_rom(struct fw_ohci *ohci,
1560 			     struct fw_packet *packet, u32 csr)
1561 {
1562 	struct fw_packet response;
1563 	int tcode, length, i;
1564 
1565 	tcode = async_header_get_tcode(packet->header);
1566 	if (tcode_is_block_packet(tcode))
1567 		length = async_header_get_data_length(packet->header);
1568 	else
1569 		length = 4;
1570 
1571 	i = csr - CSR_CONFIG_ROM;
1572 	if (i + length > CONFIG_ROM_SIZE) {
1573 		fw_fill_response(&response, packet->header,
1574 				 RCODE_ADDRESS_ERROR, NULL, 0);
1575 	} else if (!tcode_is_read_request(tcode)) {
1576 		fw_fill_response(&response, packet->header,
1577 				 RCODE_TYPE_ERROR, NULL, 0);
1578 	} else {
1579 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1580 				 (void *) ohci->config_rom + i, length);
1581 	}
1582 
1583 	// Timestamping on behalf of the hardware.
1584 	response.timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
1585 	fw_core_handle_response(&ohci->card, &response);
1586 }
1587 
1588 static void handle_local_lock(struct fw_ohci *ohci,
1589 			      struct fw_packet *packet, u32 csr)
1590 {
1591 	struct fw_packet response;
1592 	int tcode, length, ext_tcode, sel, try;
1593 	__be32 *payload, lock_old;
1594 	u32 lock_arg, lock_data;
1595 
1596 	tcode = async_header_get_tcode(packet->header);
1597 	length = async_header_get_data_length(packet->header);
1598 	payload = packet->payload;
1599 	ext_tcode = async_header_get_extended_tcode(packet->header);
1600 
1601 	if (tcode == TCODE_LOCK_REQUEST &&
1602 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1603 		lock_arg = be32_to_cpu(payload[0]);
1604 		lock_data = be32_to_cpu(payload[1]);
1605 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1606 		lock_arg = 0;
1607 		lock_data = 0;
1608 	} else {
1609 		fw_fill_response(&response, packet->header,
1610 				 RCODE_TYPE_ERROR, NULL, 0);
1611 		goto out;
1612 	}
1613 
1614 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1615 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1616 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1617 	reg_write(ohci, OHCI1394_CSRControl, sel);
1618 
1619 	for (try = 0; try < 20; try++)
1620 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1621 			lock_old = cpu_to_be32(reg_read(ohci,
1622 							OHCI1394_CSRData));
1623 			fw_fill_response(&response, packet->header,
1624 					 RCODE_COMPLETE,
1625 					 &lock_old, sizeof(lock_old));
1626 			goto out;
1627 		}
1628 
1629 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
1630 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1631 
1632  out:
1633 	// Timestamping on behalf of the hardware.
1634 	response.timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
1635 	fw_core_handle_response(&ohci->card, &response);
1636 }
1637 
1638 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1639 {
1640 	u64 offset, csr;
1641 
1642 	if (ctx == &ctx->ohci->at_request_ctx) {
1643 		packet->ack = ACK_PENDING;
1644 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1645 	}
1646 
1647 	offset = async_header_get_offset(packet->header);
1648 	csr = offset - CSR_REGISTER_BASE;
1649 
1650 	/* Handle config rom reads. */
1651 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1652 		handle_local_rom(ctx->ohci, packet, csr);
1653 	else switch (csr) {
1654 	case CSR_BUS_MANAGER_ID:
1655 	case CSR_BANDWIDTH_AVAILABLE:
1656 	case CSR_CHANNELS_AVAILABLE_HI:
1657 	case CSR_CHANNELS_AVAILABLE_LO:
1658 		handle_local_lock(ctx->ohci, packet, csr);
1659 		break;
1660 	default:
1661 		if (ctx == &ctx->ohci->at_request_ctx)
1662 			fw_core_handle_request(&ctx->ohci->card, packet);
1663 		else
1664 			fw_core_handle_response(&ctx->ohci->card, packet);
1665 		break;
1666 	}
1667 
1668 	if (ctx == &ctx->ohci->at_response_ctx) {
1669 		packet->ack = ACK_COMPLETE;
1670 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1671 	}
1672 }
1673 
1674 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1675 {
1676 	unsigned long flags;
1677 	int ret;
1678 
1679 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1680 
1681 	if (async_header_get_destination(packet->header) == ctx->ohci->node_id &&
1682 	    ctx->ohci->generation == packet->generation) {
1683 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1684 
1685 		// Timestamping on behalf of the hardware.
1686 		packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ctx->ohci));
1687 
1688 		handle_local_request(ctx, packet);
1689 		return;
1690 	}
1691 
1692 	ret = at_context_queue_packet(ctx, packet);
1693 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1694 
1695 	if (ret < 0) {
1696 		// Timestamping on behalf of the hardware.
1697 		packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ctx->ohci));
1698 
1699 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1700 	}
1701 }
1702 
1703 static void detect_dead_context(struct fw_ohci *ohci,
1704 				const char *name, unsigned int regs)
1705 {
1706 	u32 ctl;
1707 
1708 	ctl = reg_read(ohci, CONTROL_SET(regs));
1709 	if (ctl & CONTEXT_DEAD)
1710 		ohci_err(ohci, "DMA context %s has stopped, error code: %s\n",
1711 			name, evts[ctl & 0x1f]);
1712 }
1713 
1714 static void handle_dead_contexts(struct fw_ohci *ohci)
1715 {
1716 	unsigned int i;
1717 	char name[8];
1718 
1719 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1720 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1721 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1722 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1723 	for (i = 0; i < 32; ++i) {
1724 		if (!(ohci->it_context_support & (1 << i)))
1725 			continue;
1726 		sprintf(name, "IT%u", i);
1727 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1728 	}
1729 	for (i = 0; i < 32; ++i) {
1730 		if (!(ohci->ir_context_support & (1 << i)))
1731 			continue;
1732 		sprintf(name, "IR%u", i);
1733 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1734 	}
1735 	/* TODO: maybe try to flush and restart the dead contexts */
1736 }
1737 
1738 static u32 cycle_timer_ticks(u32 cycle_timer)
1739 {
1740 	u32 ticks;
1741 
1742 	ticks = cycle_timer & 0xfff;
1743 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1744 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1745 
1746 	return ticks;
1747 }
1748 
1749 /*
1750  * Some controllers exhibit one or more of the following bugs when updating the
1751  * iso cycle timer register:
1752  *  - When the lowest six bits are wrapping around to zero, a read that happens
1753  *    at the same time will return garbage in the lowest ten bits.
1754  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1755  *    not incremented for about 60 ns.
1756  *  - Occasionally, the entire register reads zero.
1757  *
1758  * To catch these, we read the register three times and ensure that the
1759  * difference between each two consecutive reads is approximately the same, i.e.
1760  * less than twice the other.  Furthermore, any negative difference indicates an
1761  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1762  * execute, so we have enough precision to compute the ratio of the differences.)
1763  */
1764 static u32 get_cycle_time(struct fw_ohci *ohci)
1765 {
1766 	u32 c0, c1, c2;
1767 	u32 t0, t1, t2;
1768 	s32 diff01, diff12;
1769 	int i;
1770 
1771 	if (has_reboot_by_cycle_timer_read_quirk(ohci))
1772 		return 0;
1773 
1774 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1775 
1776 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1777 		i = 0;
1778 		c1 = c2;
1779 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1780 		do {
1781 			c0 = c1;
1782 			c1 = c2;
1783 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1784 			t0 = cycle_timer_ticks(c0);
1785 			t1 = cycle_timer_ticks(c1);
1786 			t2 = cycle_timer_ticks(c2);
1787 			diff01 = t1 - t0;
1788 			diff12 = t2 - t1;
1789 		} while ((diff01 <= 0 || diff12 <= 0 ||
1790 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1791 			 && i++ < 20);
1792 	}
1793 
1794 	return c2;
1795 }
1796 
1797 /*
1798  * This function has to be called at least every 64 seconds.  The bus_time
1799  * field stores not only the upper 25 bits of the BUS_TIME register but also
1800  * the most significant bit of the cycle timer in bit 6 so that we can detect
1801  * changes in this bit.
1802  */
1803 static u32 update_bus_time(struct fw_ohci *ohci)
1804 {
1805 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1806 
1807 	if (unlikely(!ohci->bus_time_running)) {
1808 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds);
1809 		ohci->bus_time = (lower_32_bits(ktime_get_seconds()) & ~0x7f) |
1810 		                 (cycle_time_seconds & 0x40);
1811 		ohci->bus_time_running = true;
1812 	}
1813 
1814 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1815 		ohci->bus_time += 0x40;
1816 
1817 	return ohci->bus_time | cycle_time_seconds;
1818 }
1819 
1820 static int get_status_for_port(struct fw_ohci *ohci, int port_index)
1821 {
1822 	int reg;
1823 
1824 	mutex_lock(&ohci->phy_reg_mutex);
1825 	reg = write_phy_reg(ohci, 7, port_index);
1826 	if (reg >= 0)
1827 		reg = read_phy_reg(ohci, 8);
1828 	mutex_unlock(&ohci->phy_reg_mutex);
1829 	if (reg < 0)
1830 		return reg;
1831 
1832 	switch (reg & 0x0f) {
1833 	case 0x06:
1834 		return 2;	/* is child node (connected to parent node) */
1835 	case 0x0e:
1836 		return 3;	/* is parent node (connected to child node) */
1837 	}
1838 	return 1;		/* not connected */
1839 }
1840 
1841 static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
1842 	int self_id_count)
1843 {
1844 	int i;
1845 	u32 entry;
1846 
1847 	for (i = 0; i < self_id_count; i++) {
1848 		entry = ohci->self_id_buffer[i];
1849 		if ((self_id & 0xff000000) == (entry & 0xff000000))
1850 			return -1;
1851 		if ((self_id & 0xff000000) < (entry & 0xff000000))
1852 			return i;
1853 	}
1854 	return i;
1855 }
1856 
1857 static int initiated_reset(struct fw_ohci *ohci)
1858 {
1859 	int reg;
1860 	int ret = 0;
1861 
1862 	mutex_lock(&ohci->phy_reg_mutex);
1863 	reg = write_phy_reg(ohci, 7, 0xe0); /* Select page 7 */
1864 	if (reg >= 0) {
1865 		reg = read_phy_reg(ohci, 8);
1866 		reg |= 0x40;
1867 		reg = write_phy_reg(ohci, 8, reg); /* set PMODE bit */
1868 		if (reg >= 0) {
1869 			reg = read_phy_reg(ohci, 12); /* read register 12 */
1870 			if (reg >= 0) {
1871 				if ((reg & 0x08) == 0x08) {
1872 					/* bit 3 indicates "initiated reset" */
1873 					ret = 0x2;
1874 				}
1875 			}
1876 		}
1877 	}
1878 	mutex_unlock(&ohci->phy_reg_mutex);
1879 	return ret;
1880 }
1881 
1882 /*
1883  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
1884  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
1885  * Construct the selfID from phy register contents.
1886  */
1887 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
1888 {
1889 	int reg, i, pos, status;
1890 	/* link active 1, speed 3, bridge 0, contender 1, more packets 0 */
1891 	u32 self_id = 0x8040c800;
1892 
1893 	reg = reg_read(ohci, OHCI1394_NodeID);
1894 	if (!(reg & OHCI1394_NodeID_idValid)) {
1895 		ohci_notice(ohci,
1896 			    "node ID not valid, new bus reset in progress\n");
1897 		return -EBUSY;
1898 	}
1899 	self_id |= ((reg & 0x3f) << 24); /* phy ID */
1900 
1901 	reg = ohci_read_phy_reg(&ohci->card, 4);
1902 	if (reg < 0)
1903 		return reg;
1904 	self_id |= ((reg & 0x07) << 8); /* power class */
1905 
1906 	reg = ohci_read_phy_reg(&ohci->card, 1);
1907 	if (reg < 0)
1908 		return reg;
1909 	self_id |= ((reg & 0x3f) << 16); /* gap count */
1910 
1911 	for (i = 0; i < 3; i++) {
1912 		status = get_status_for_port(ohci, i);
1913 		if (status < 0)
1914 			return status;
1915 		self_id |= ((status & 0x3) << (6 - (i * 2)));
1916 	}
1917 
1918 	self_id |= initiated_reset(ohci);
1919 
1920 	pos = get_self_id_pos(ohci, self_id, self_id_count);
1921 	if (pos >= 0) {
1922 		memmove(&(ohci->self_id_buffer[pos+1]),
1923 			&(ohci->self_id_buffer[pos]),
1924 			(self_id_count - pos) * sizeof(*ohci->self_id_buffer));
1925 		ohci->self_id_buffer[pos] = self_id;
1926 		self_id_count++;
1927 	}
1928 	return self_id_count;
1929 }
1930 
1931 static void bus_reset_work(struct work_struct *work)
1932 {
1933 	struct fw_ohci *ohci =
1934 		container_of(work, struct fw_ohci, bus_reset_work);
1935 	int self_id_count, generation, new_generation, i, j;
1936 	u32 reg;
1937 	void *free_rom = NULL;
1938 	dma_addr_t free_rom_bus = 0;
1939 	bool is_new_root;
1940 
1941 	reg = reg_read(ohci, OHCI1394_NodeID);
1942 	if (!(reg & OHCI1394_NodeID_idValid)) {
1943 		ohci_notice(ohci,
1944 			    "node ID not valid, new bus reset in progress\n");
1945 		return;
1946 	}
1947 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1948 		ohci_notice(ohci, "malconfigured bus\n");
1949 		return;
1950 	}
1951 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1952 			       OHCI1394_NodeID_nodeNumber);
1953 
1954 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1955 	if (!(ohci->is_root && is_new_root))
1956 		reg_write(ohci, OHCI1394_LinkControlSet,
1957 			  OHCI1394_LinkControl_cycleMaster);
1958 	ohci->is_root = is_new_root;
1959 
1960 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1961 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1962 		ohci_notice(ohci, "self ID receive error\n");
1963 		return;
1964 	}
1965 	/*
1966 	 * The count in the SelfIDCount register is the number of
1967 	 * bytes in the self ID receive buffer.  Since we also receive
1968 	 * the inverted quadlets and a header quadlet, we shift one
1969 	 * bit extra to get the actual number of self IDs.
1970 	 */
1971 	self_id_count = (reg >> 3) & 0xff;
1972 
1973 	if (self_id_count > 252) {
1974 		ohci_notice(ohci, "bad selfIDSize (%08x)\n", reg);
1975 		return;
1976 	}
1977 
1978 	generation = (cond_le32_to_cpu(ohci->self_id[0]) >> 16) & 0xff;
1979 	rmb();
1980 
1981 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1982 		u32 id  = cond_le32_to_cpu(ohci->self_id[i]);
1983 		u32 id2 = cond_le32_to_cpu(ohci->self_id[i + 1]);
1984 
1985 		if (id != ~id2) {
1986 			/*
1987 			 * If the invalid data looks like a cycle start packet,
1988 			 * it's likely to be the result of the cycle master
1989 			 * having a wrong gap count.  In this case, the self IDs
1990 			 * so far are valid and should be processed so that the
1991 			 * bus manager can then correct the gap count.
1992 			 */
1993 			if (id == 0xffff008f) {
1994 				ohci_notice(ohci, "ignoring spurious self IDs\n");
1995 				self_id_count = j;
1996 				break;
1997 			}
1998 
1999 			ohci_notice(ohci, "bad self ID %d/%d (%08x != ~%08x)\n",
2000 				    j, self_id_count, id, id2);
2001 			return;
2002 		}
2003 		ohci->self_id_buffer[j] = id;
2004 	}
2005 
2006 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2007 		self_id_count = find_and_insert_self_id(ohci, self_id_count);
2008 		if (self_id_count < 0) {
2009 			ohci_notice(ohci,
2010 				    "could not construct local self ID\n");
2011 			return;
2012 		}
2013 	}
2014 
2015 	if (self_id_count == 0) {
2016 		ohci_notice(ohci, "no self IDs\n");
2017 		return;
2018 	}
2019 	rmb();
2020 
2021 	/*
2022 	 * Check the consistency of the self IDs we just read.  The
2023 	 * problem we face is that a new bus reset can start while we
2024 	 * read out the self IDs from the DMA buffer. If this happens,
2025 	 * the DMA buffer will be overwritten with new self IDs and we
2026 	 * will read out inconsistent data.  The OHCI specification
2027 	 * (section 11.2) recommends a technique similar to
2028 	 * linux/seqlock.h, where we remember the generation of the
2029 	 * self IDs in the buffer before reading them out and compare
2030 	 * it to the current generation after reading them out.  If
2031 	 * the two generations match we know we have a consistent set
2032 	 * of self IDs.
2033 	 */
2034 
2035 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
2036 	if (new_generation != generation) {
2037 		ohci_notice(ohci, "new bus reset, discarding self ids\n");
2038 		return;
2039 	}
2040 
2041 	/* FIXME: Document how the locking works. */
2042 	spin_lock_irq(&ohci->lock);
2043 
2044 	ohci->generation = -1; /* prevent AT packet queueing */
2045 	context_stop(&ohci->at_request_ctx);
2046 	context_stop(&ohci->at_response_ctx);
2047 
2048 	spin_unlock_irq(&ohci->lock);
2049 
2050 	/*
2051 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
2052 	 * packets in the AT queues and software needs to drain them.
2053 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
2054 	 */
2055 	at_context_flush(&ohci->at_request_ctx);
2056 	at_context_flush(&ohci->at_response_ctx);
2057 
2058 	spin_lock_irq(&ohci->lock);
2059 
2060 	ohci->generation = generation;
2061 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
2062 	reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_busReset);
2063 
2064 	if (ohci->quirks & QUIRK_RESET_PACKET)
2065 		ohci->request_generation = generation;
2066 
2067 	/*
2068 	 * This next bit is unrelated to the AT context stuff but we
2069 	 * have to do it under the spinlock also.  If a new config rom
2070 	 * was set up before this reset, the old one is now no longer
2071 	 * in use and we can free it. Update the config rom pointers
2072 	 * to point to the current config rom and clear the
2073 	 * next_config_rom pointer so a new update can take place.
2074 	 */
2075 
2076 	if (ohci->next_config_rom != NULL) {
2077 		if (ohci->next_config_rom != ohci->config_rom) {
2078 			free_rom      = ohci->config_rom;
2079 			free_rom_bus  = ohci->config_rom_bus;
2080 		}
2081 		ohci->config_rom      = ohci->next_config_rom;
2082 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
2083 		ohci->next_config_rom = NULL;
2084 
2085 		/*
2086 		 * Restore config_rom image and manually update
2087 		 * config_rom registers.  Writing the header quadlet
2088 		 * will indicate that the config rom is ready, so we
2089 		 * do that last.
2090 		 */
2091 		reg_write(ohci, OHCI1394_BusOptions,
2092 			  be32_to_cpu(ohci->config_rom[2]));
2093 		ohci->config_rom[0] = ohci->next_header;
2094 		reg_write(ohci, OHCI1394_ConfigROMhdr,
2095 			  be32_to_cpu(ohci->next_header));
2096 	}
2097 
2098 	if (param_remote_dma) {
2099 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
2100 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
2101 	}
2102 
2103 	spin_unlock_irq(&ohci->lock);
2104 
2105 	if (free_rom)
2106 		dmam_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, free_rom, free_rom_bus);
2107 
2108 	log_selfids(ohci, generation, self_id_count);
2109 
2110 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
2111 				 self_id_count, ohci->self_id_buffer,
2112 				 ohci->csr_state_setclear_abdicate);
2113 	ohci->csr_state_setclear_abdicate = false;
2114 }
2115 
2116 static irqreturn_t irq_handler(int irq, void *data)
2117 {
2118 	struct fw_ohci *ohci = data;
2119 	u32 event, iso_event;
2120 	int i;
2121 
2122 	event = reg_read(ohci, OHCI1394_IntEventClear);
2123 
2124 	if (!event || !~event)
2125 		return IRQ_NONE;
2126 
2127 	/*
2128 	 * busReset and postedWriteErr events must not be cleared yet
2129 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
2130 	 */
2131 	reg_write(ohci, OHCI1394_IntEventClear,
2132 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
2133 	log_irqs(ohci, event);
2134 	// The flag is masked again at bus_reset_work() scheduled by selfID event.
2135 	if (event & OHCI1394_busReset)
2136 		reg_write(ohci, OHCI1394_IntMaskClear, OHCI1394_busReset);
2137 
2138 	if (event & OHCI1394_selfIDComplete)
2139 		queue_work(selfid_workqueue, &ohci->bus_reset_work);
2140 
2141 	if (event & OHCI1394_RQPkt)
2142 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
2143 
2144 	if (event & OHCI1394_RSPkt)
2145 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
2146 
2147 	if (event & OHCI1394_reqTxComplete)
2148 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
2149 
2150 	if (event & OHCI1394_respTxComplete)
2151 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
2152 
2153 	if (event & OHCI1394_isochRx) {
2154 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
2155 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
2156 
2157 		while (iso_event) {
2158 			i = ffs(iso_event) - 1;
2159 			tasklet_schedule(
2160 				&ohci->ir_context_list[i].context.tasklet);
2161 			iso_event &= ~(1 << i);
2162 		}
2163 	}
2164 
2165 	if (event & OHCI1394_isochTx) {
2166 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
2167 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
2168 
2169 		while (iso_event) {
2170 			i = ffs(iso_event) - 1;
2171 			tasklet_schedule(
2172 				&ohci->it_context_list[i].context.tasklet);
2173 			iso_event &= ~(1 << i);
2174 		}
2175 	}
2176 
2177 	if (unlikely(event & OHCI1394_regAccessFail))
2178 		ohci_err(ohci, "register access failure\n");
2179 
2180 	if (unlikely(event & OHCI1394_postedWriteErr)) {
2181 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
2182 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
2183 		reg_write(ohci, OHCI1394_IntEventClear,
2184 			  OHCI1394_postedWriteErr);
2185 		if (printk_ratelimit())
2186 			ohci_err(ohci, "PCI posted write error\n");
2187 	}
2188 
2189 	if (unlikely(event & OHCI1394_cycleTooLong)) {
2190 		if (printk_ratelimit())
2191 			ohci_notice(ohci, "isochronous cycle too long\n");
2192 		reg_write(ohci, OHCI1394_LinkControlSet,
2193 			  OHCI1394_LinkControl_cycleMaster);
2194 	}
2195 
2196 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
2197 		/*
2198 		 * We need to clear this event bit in order to make
2199 		 * cycleMatch isochronous I/O work.  In theory we should
2200 		 * stop active cycleMatch iso contexts now and restart
2201 		 * them at least two cycles later.  (FIXME?)
2202 		 */
2203 		if (printk_ratelimit())
2204 			ohci_notice(ohci, "isochronous cycle inconsistent\n");
2205 	}
2206 
2207 	if (unlikely(event & OHCI1394_unrecoverableError))
2208 		handle_dead_contexts(ohci);
2209 
2210 	if (event & OHCI1394_cycle64Seconds) {
2211 		spin_lock(&ohci->lock);
2212 		update_bus_time(ohci);
2213 		spin_unlock(&ohci->lock);
2214 	} else
2215 		flush_writes(ohci);
2216 
2217 	return IRQ_HANDLED;
2218 }
2219 
2220 static int software_reset(struct fw_ohci *ohci)
2221 {
2222 	u32 val;
2223 	int i;
2224 
2225 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
2226 	for (i = 0; i < 500; i++) {
2227 		val = reg_read(ohci, OHCI1394_HCControlSet);
2228 		if (!~val)
2229 			return -ENODEV; /* Card was ejected. */
2230 
2231 		if (!(val & OHCI1394_HCControl_softReset))
2232 			return 0;
2233 
2234 		msleep(1);
2235 	}
2236 
2237 	return -EBUSY;
2238 }
2239 
2240 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
2241 {
2242 	size_t size = length * 4;
2243 
2244 	memcpy(dest, src, size);
2245 	if (size < CONFIG_ROM_SIZE)
2246 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
2247 }
2248 
2249 static int configure_1394a_enhancements(struct fw_ohci *ohci)
2250 {
2251 	bool enable_1394a;
2252 	int ret, clear, set, offset;
2253 
2254 	/* Check if the driver should configure link and PHY. */
2255 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
2256 	      OHCI1394_HCControl_programPhyEnable))
2257 		return 0;
2258 
2259 	/* Paranoia: check whether the PHY supports 1394a, too. */
2260 	enable_1394a = false;
2261 	ret = read_phy_reg(ohci, 2);
2262 	if (ret < 0)
2263 		return ret;
2264 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2265 		ret = read_paged_phy_reg(ohci, 1, 8);
2266 		if (ret < 0)
2267 			return ret;
2268 		if (ret >= 1)
2269 			enable_1394a = true;
2270 	}
2271 
2272 	if (ohci->quirks & QUIRK_NO_1394A)
2273 		enable_1394a = false;
2274 
2275 	/* Configure PHY and link consistently. */
2276 	if (enable_1394a) {
2277 		clear = 0;
2278 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2279 	} else {
2280 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2281 		set = 0;
2282 	}
2283 	ret = update_phy_reg(ohci, 5, clear, set);
2284 	if (ret < 0)
2285 		return ret;
2286 
2287 	if (enable_1394a)
2288 		offset = OHCI1394_HCControlSet;
2289 	else
2290 		offset = OHCI1394_HCControlClear;
2291 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2292 
2293 	/* Clean up: configuration has been taken care of. */
2294 	reg_write(ohci, OHCI1394_HCControlClear,
2295 		  OHCI1394_HCControl_programPhyEnable);
2296 
2297 	return 0;
2298 }
2299 
2300 static int probe_tsb41ba3d(struct fw_ohci *ohci)
2301 {
2302 	/* TI vendor ID = 0x080028, TSB41BA3D product ID = 0x833005 (sic) */
2303 	static const u8 id[] = { 0x08, 0x00, 0x28, 0x83, 0x30, 0x05, };
2304 	int reg, i;
2305 
2306 	reg = read_phy_reg(ohci, 2);
2307 	if (reg < 0)
2308 		return reg;
2309 	if ((reg & PHY_EXTENDED_REGISTERS) != PHY_EXTENDED_REGISTERS)
2310 		return 0;
2311 
2312 	for (i = ARRAY_SIZE(id) - 1; i >= 0; i--) {
2313 		reg = read_paged_phy_reg(ohci, 1, i + 10);
2314 		if (reg < 0)
2315 			return reg;
2316 		if (reg != id[i])
2317 			return 0;
2318 	}
2319 	return 1;
2320 }
2321 
2322 static int ohci_enable(struct fw_card *card,
2323 		       const __be32 *config_rom, size_t length)
2324 {
2325 	struct fw_ohci *ohci = fw_ohci(card);
2326 	u32 lps, version, irqs;
2327 	int i, ret;
2328 
2329 	ret = software_reset(ohci);
2330 	if (ret < 0) {
2331 		ohci_err(ohci, "failed to reset ohci card\n");
2332 		return ret;
2333 	}
2334 
2335 	/*
2336 	 * Now enable LPS, which we need in order to start accessing
2337 	 * most of the registers.  In fact, on some cards (ALI M5251),
2338 	 * accessing registers in the SClk domain without LPS enabled
2339 	 * will lock up the machine.  Wait 50msec to make sure we have
2340 	 * full link enabled.  However, with some cards (well, at least
2341 	 * a JMicron PCIe card), we have to try again sometimes.
2342 	 *
2343 	 * TI TSB82AA2 + TSB81BA3(A) cards signal LPS enabled early but
2344 	 * cannot actually use the phy at that time.  These need tens of
2345 	 * millisecods pause between LPS write and first phy access too.
2346 	 */
2347 
2348 	reg_write(ohci, OHCI1394_HCControlSet,
2349 		  OHCI1394_HCControl_LPS |
2350 		  OHCI1394_HCControl_postedWriteEnable);
2351 	flush_writes(ohci);
2352 
2353 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2354 		msleep(50);
2355 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2356 		      OHCI1394_HCControl_LPS;
2357 	}
2358 
2359 	if (!lps) {
2360 		ohci_err(ohci, "failed to set Link Power Status\n");
2361 		return -EIO;
2362 	}
2363 
2364 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2365 		ret = probe_tsb41ba3d(ohci);
2366 		if (ret < 0)
2367 			return ret;
2368 		if (ret)
2369 			ohci_notice(ohci, "local TSB41BA3D phy\n");
2370 		else
2371 			ohci->quirks &= ~QUIRK_TI_SLLZ059;
2372 	}
2373 
2374 	reg_write(ohci, OHCI1394_HCControlClear,
2375 		  OHCI1394_HCControl_noByteSwapData);
2376 
2377 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2378 	reg_write(ohci, OHCI1394_LinkControlSet,
2379 		  OHCI1394_LinkControl_cycleTimerEnable |
2380 		  OHCI1394_LinkControl_cycleMaster);
2381 
2382 	reg_write(ohci, OHCI1394_ATRetries,
2383 		  OHCI1394_MAX_AT_REQ_RETRIES |
2384 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2385 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2386 		  (200 << 16));
2387 
2388 	ohci->bus_time_running = false;
2389 
2390 	for (i = 0; i < 32; i++)
2391 		if (ohci->ir_context_support & (1 << i))
2392 			reg_write(ohci, OHCI1394_IsoRcvContextControlClear(i),
2393 				  IR_CONTEXT_MULTI_CHANNEL_MODE);
2394 
2395 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2396 	if (version >= OHCI_VERSION_1_1) {
2397 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2398 			  0xfffffffe);
2399 		card->broadcast_channel_auto_allocated = true;
2400 	}
2401 
2402 	/* Get implemented bits of the priority arbitration request counter. */
2403 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2404 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2405 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2406 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2407 
2408 	reg_write(ohci, OHCI1394_PhyUpperBound, FW_MAX_PHYSICAL_RANGE >> 16);
2409 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2410 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2411 
2412 	ret = configure_1394a_enhancements(ohci);
2413 	if (ret < 0)
2414 		return ret;
2415 
2416 	/* Activate link_on bit and contender bit in our self ID packets.*/
2417 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2418 	if (ret < 0)
2419 		return ret;
2420 
2421 	/*
2422 	 * When the link is not yet enabled, the atomic config rom
2423 	 * update mechanism described below in ohci_set_config_rom()
2424 	 * is not active.  We have to update ConfigRomHeader and
2425 	 * BusOptions manually, and the write to ConfigROMmap takes
2426 	 * effect immediately.  We tie this to the enabling of the
2427 	 * link, so we have a valid config rom before enabling - the
2428 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2429 	 * values before enabling.
2430 	 *
2431 	 * However, when the ConfigROMmap is written, some controllers
2432 	 * always read back quadlets 0 and 2 from the config rom to
2433 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2434 	 * They shouldn't do that in this initial case where the link
2435 	 * isn't enabled.  This means we have to use the same
2436 	 * workaround here, setting the bus header to 0 and then write
2437 	 * the right values in the bus reset tasklet.
2438 	 */
2439 
2440 	if (config_rom) {
2441 		ohci->next_config_rom = dmam_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2442 							    &ohci->next_config_rom_bus, GFP_KERNEL);
2443 		if (ohci->next_config_rom == NULL)
2444 			return -ENOMEM;
2445 
2446 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2447 	} else {
2448 		/*
2449 		 * In the suspend case, config_rom is NULL, which
2450 		 * means that we just reuse the old config rom.
2451 		 */
2452 		ohci->next_config_rom = ohci->config_rom;
2453 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2454 	}
2455 
2456 	ohci->next_header = ohci->next_config_rom[0];
2457 	ohci->next_config_rom[0] = 0;
2458 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2459 	reg_write(ohci, OHCI1394_BusOptions,
2460 		  be32_to_cpu(ohci->next_config_rom[2]));
2461 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2462 
2463 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2464 
2465 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2466 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2467 		OHCI1394_isochTx | OHCI1394_isochRx |
2468 		OHCI1394_postedWriteErr |
2469 		OHCI1394_selfIDComplete |
2470 		OHCI1394_regAccessFail |
2471 		OHCI1394_cycleInconsistent |
2472 		OHCI1394_unrecoverableError |
2473 		OHCI1394_cycleTooLong |
2474 		OHCI1394_masterIntEnable |
2475 		OHCI1394_busReset;
2476 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2477 
2478 	reg_write(ohci, OHCI1394_HCControlSet,
2479 		  OHCI1394_HCControl_linkEnable |
2480 		  OHCI1394_HCControl_BIBimageValid);
2481 
2482 	reg_write(ohci, OHCI1394_LinkControlSet,
2483 		  OHCI1394_LinkControl_rcvSelfID |
2484 		  OHCI1394_LinkControl_rcvPhyPkt);
2485 
2486 	ar_context_run(&ohci->ar_request_ctx);
2487 	ar_context_run(&ohci->ar_response_ctx);
2488 
2489 	flush_writes(ohci);
2490 
2491 	/* We are ready to go, reset bus to finish initialization. */
2492 	fw_schedule_bus_reset(&ohci->card, false, true);
2493 
2494 	return 0;
2495 }
2496 
2497 static int ohci_set_config_rom(struct fw_card *card,
2498 			       const __be32 *config_rom, size_t length)
2499 {
2500 	struct fw_ohci *ohci;
2501 	__be32 *next_config_rom;
2502 	dma_addr_t next_config_rom_bus;
2503 
2504 	ohci = fw_ohci(card);
2505 
2506 	/*
2507 	 * When the OHCI controller is enabled, the config rom update
2508 	 * mechanism is a bit tricky, but easy enough to use.  See
2509 	 * section 5.5.6 in the OHCI specification.
2510 	 *
2511 	 * The OHCI controller caches the new config rom address in a
2512 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2513 	 * for the changes to take place.  When the bus reset is
2514 	 * detected, the controller loads the new values for the
2515 	 * ConfigRomHeader and BusOptions registers from the specified
2516 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2517 	 * shadow register. All automatically and atomically.
2518 	 *
2519 	 * Now, there's a twist to this story.  The automatic load of
2520 	 * ConfigRomHeader and BusOptions doesn't honor the
2521 	 * noByteSwapData bit, so with a be32 config rom, the
2522 	 * controller will load be32 values in to these registers
2523 	 * during the atomic update, even on litte endian
2524 	 * architectures.  The workaround we use is to put a 0 in the
2525 	 * header quadlet; 0 is endian agnostic and means that the
2526 	 * config rom isn't ready yet.  In the bus reset tasklet we
2527 	 * then set up the real values for the two registers.
2528 	 *
2529 	 * We use ohci->lock to avoid racing with the code that sets
2530 	 * ohci->next_config_rom to NULL (see bus_reset_work).
2531 	 */
2532 
2533 	next_config_rom = dmam_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2534 					      &next_config_rom_bus, GFP_KERNEL);
2535 	if (next_config_rom == NULL)
2536 		return -ENOMEM;
2537 
2538 	spin_lock_irq(&ohci->lock);
2539 
2540 	/*
2541 	 * If there is not an already pending config_rom update,
2542 	 * push our new allocation into the ohci->next_config_rom
2543 	 * and then mark the local variable as null so that we
2544 	 * won't deallocate the new buffer.
2545 	 *
2546 	 * OTOH, if there is a pending config_rom update, just
2547 	 * use that buffer with the new config_rom data, and
2548 	 * let this routine free the unused DMA allocation.
2549 	 */
2550 
2551 	if (ohci->next_config_rom == NULL) {
2552 		ohci->next_config_rom = next_config_rom;
2553 		ohci->next_config_rom_bus = next_config_rom_bus;
2554 		next_config_rom = NULL;
2555 	}
2556 
2557 	copy_config_rom(ohci->next_config_rom, config_rom, length);
2558 
2559 	ohci->next_header = config_rom[0];
2560 	ohci->next_config_rom[0] = 0;
2561 
2562 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2563 
2564 	spin_unlock_irq(&ohci->lock);
2565 
2566 	/* If we didn't use the DMA allocation, delete it. */
2567 	if (next_config_rom != NULL) {
2568 		dmam_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, next_config_rom,
2569 				   next_config_rom_bus);
2570 	}
2571 
2572 	/*
2573 	 * Now initiate a bus reset to have the changes take
2574 	 * effect. We clean up the old config rom memory and DMA
2575 	 * mappings in the bus reset tasklet, since the OHCI
2576 	 * controller could need to access it before the bus reset
2577 	 * takes effect.
2578 	 */
2579 
2580 	fw_schedule_bus_reset(&ohci->card, true, true);
2581 
2582 	return 0;
2583 }
2584 
2585 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2586 {
2587 	struct fw_ohci *ohci = fw_ohci(card);
2588 
2589 	at_context_transmit(&ohci->at_request_ctx, packet);
2590 }
2591 
2592 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2593 {
2594 	struct fw_ohci *ohci = fw_ohci(card);
2595 
2596 	at_context_transmit(&ohci->at_response_ctx, packet);
2597 }
2598 
2599 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2600 {
2601 	struct fw_ohci *ohci = fw_ohci(card);
2602 	struct context *ctx = &ohci->at_request_ctx;
2603 	struct driver_data *driver_data = packet->driver_data;
2604 	int ret = -ENOENT;
2605 
2606 	tasklet_disable_in_atomic(&ctx->tasklet);
2607 
2608 	if (packet->ack != 0)
2609 		goto out;
2610 
2611 	if (packet->payload_mapped)
2612 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2613 				 packet->payload_length, DMA_TO_DEVICE);
2614 
2615 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, 0x20);
2616 	driver_data->packet = NULL;
2617 	packet->ack = RCODE_CANCELLED;
2618 
2619 	// Timestamping on behalf of the hardware.
2620 	packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
2621 
2622 	packet->callback(packet, &ohci->card, packet->ack);
2623 	ret = 0;
2624  out:
2625 	tasklet_enable(&ctx->tasklet);
2626 
2627 	return ret;
2628 }
2629 
2630 static int ohci_enable_phys_dma(struct fw_card *card,
2631 				int node_id, int generation)
2632 {
2633 	struct fw_ohci *ohci = fw_ohci(card);
2634 	unsigned long flags;
2635 	int n, ret = 0;
2636 
2637 	if (param_remote_dma)
2638 		return 0;
2639 
2640 	/*
2641 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2642 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2643 	 */
2644 
2645 	spin_lock_irqsave(&ohci->lock, flags);
2646 
2647 	if (ohci->generation != generation) {
2648 		ret = -ESTALE;
2649 		goto out;
2650 	}
2651 
2652 	/*
2653 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2654 	 * enabled for _all_ nodes on remote buses.
2655 	 */
2656 
2657 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2658 	if (n < 32)
2659 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2660 	else
2661 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2662 
2663 	flush_writes(ohci);
2664  out:
2665 	spin_unlock_irqrestore(&ohci->lock, flags);
2666 
2667 	return ret;
2668 }
2669 
2670 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2671 {
2672 	struct fw_ohci *ohci = fw_ohci(card);
2673 	unsigned long flags;
2674 	u32 value;
2675 
2676 	switch (csr_offset) {
2677 	case CSR_STATE_CLEAR:
2678 	case CSR_STATE_SET:
2679 		if (ohci->is_root &&
2680 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2681 		     OHCI1394_LinkControl_cycleMaster))
2682 			value = CSR_STATE_BIT_CMSTR;
2683 		else
2684 			value = 0;
2685 		if (ohci->csr_state_setclear_abdicate)
2686 			value |= CSR_STATE_BIT_ABDICATE;
2687 
2688 		return value;
2689 
2690 	case CSR_NODE_IDS:
2691 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2692 
2693 	case CSR_CYCLE_TIME:
2694 		return get_cycle_time(ohci);
2695 
2696 	case CSR_BUS_TIME:
2697 		/*
2698 		 * We might be called just after the cycle timer has wrapped
2699 		 * around but just before the cycle64Seconds handler, so we
2700 		 * better check here, too, if the bus time needs to be updated.
2701 		 */
2702 		spin_lock_irqsave(&ohci->lock, flags);
2703 		value = update_bus_time(ohci);
2704 		spin_unlock_irqrestore(&ohci->lock, flags);
2705 		return value;
2706 
2707 	case CSR_BUSY_TIMEOUT:
2708 		value = reg_read(ohci, OHCI1394_ATRetries);
2709 		return (value >> 4) & 0x0ffff00f;
2710 
2711 	case CSR_PRIORITY_BUDGET:
2712 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2713 			(ohci->pri_req_max << 8);
2714 
2715 	default:
2716 		WARN_ON(1);
2717 		return 0;
2718 	}
2719 }
2720 
2721 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2722 {
2723 	struct fw_ohci *ohci = fw_ohci(card);
2724 	unsigned long flags;
2725 
2726 	switch (csr_offset) {
2727 	case CSR_STATE_CLEAR:
2728 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2729 			reg_write(ohci, OHCI1394_LinkControlClear,
2730 				  OHCI1394_LinkControl_cycleMaster);
2731 			flush_writes(ohci);
2732 		}
2733 		if (value & CSR_STATE_BIT_ABDICATE)
2734 			ohci->csr_state_setclear_abdicate = false;
2735 		break;
2736 
2737 	case CSR_STATE_SET:
2738 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2739 			reg_write(ohci, OHCI1394_LinkControlSet,
2740 				  OHCI1394_LinkControl_cycleMaster);
2741 			flush_writes(ohci);
2742 		}
2743 		if (value & CSR_STATE_BIT_ABDICATE)
2744 			ohci->csr_state_setclear_abdicate = true;
2745 		break;
2746 
2747 	case CSR_NODE_IDS:
2748 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2749 		flush_writes(ohci);
2750 		break;
2751 
2752 	case CSR_CYCLE_TIME:
2753 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2754 		reg_write(ohci, OHCI1394_IntEventSet,
2755 			  OHCI1394_cycleInconsistent);
2756 		flush_writes(ohci);
2757 		break;
2758 
2759 	case CSR_BUS_TIME:
2760 		spin_lock_irqsave(&ohci->lock, flags);
2761 		ohci->bus_time = (update_bus_time(ohci) & 0x40) |
2762 		                 (value & ~0x7f);
2763 		spin_unlock_irqrestore(&ohci->lock, flags);
2764 		break;
2765 
2766 	case CSR_BUSY_TIMEOUT:
2767 		value = (value & 0xf) | ((value & 0xf) << 4) |
2768 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2769 		reg_write(ohci, OHCI1394_ATRetries, value);
2770 		flush_writes(ohci);
2771 		break;
2772 
2773 	case CSR_PRIORITY_BUDGET:
2774 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2775 		flush_writes(ohci);
2776 		break;
2777 
2778 	default:
2779 		WARN_ON(1);
2780 		break;
2781 	}
2782 }
2783 
2784 static void flush_iso_completions(struct iso_context *ctx)
2785 {
2786 	ctx->base.callback.sc(&ctx->base, ctx->last_timestamp,
2787 			      ctx->header_length, ctx->header,
2788 			      ctx->base.callback_data);
2789 	ctx->header_length = 0;
2790 }
2791 
2792 static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
2793 {
2794 	u32 *ctx_hdr;
2795 
2796 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
2797 		if (ctx->base.drop_overflow_headers)
2798 			return;
2799 		flush_iso_completions(ctx);
2800 	}
2801 
2802 	ctx_hdr = ctx->header + ctx->header_length;
2803 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
2804 
2805 	/*
2806 	 * The two iso header quadlets are byteswapped to little
2807 	 * endian by the controller, but we want to present them
2808 	 * as big endian for consistency with the bus endianness.
2809 	 */
2810 	if (ctx->base.header_size > 0)
2811 		ctx_hdr[0] = swab32(dma_hdr[1]); /* iso packet header */
2812 	if (ctx->base.header_size > 4)
2813 		ctx_hdr[1] = swab32(dma_hdr[0]); /* timestamp */
2814 	if (ctx->base.header_size > 8)
2815 		memcpy(&ctx_hdr[2], &dma_hdr[2], ctx->base.header_size - 8);
2816 	ctx->header_length += ctx->base.header_size;
2817 }
2818 
2819 static int handle_ir_packet_per_buffer(struct context *context,
2820 				       struct descriptor *d,
2821 				       struct descriptor *last)
2822 {
2823 	struct iso_context *ctx =
2824 		container_of(context, struct iso_context, context);
2825 	struct descriptor *pd;
2826 	u32 buffer_dma;
2827 
2828 	for (pd = d; pd <= last; pd++)
2829 		if (pd->transfer_status)
2830 			break;
2831 	if (pd > last)
2832 		/* Descriptor(s) not done yet, stop iteration */
2833 		return 0;
2834 
2835 	while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
2836 		d++;
2837 		buffer_dma = le32_to_cpu(d->data_address);
2838 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2839 					      buffer_dma & PAGE_MASK,
2840 					      buffer_dma & ~PAGE_MASK,
2841 					      le16_to_cpu(d->req_count),
2842 					      DMA_FROM_DEVICE);
2843 	}
2844 
2845 	copy_iso_headers(ctx, (u32 *) (last + 1));
2846 
2847 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2848 		flush_iso_completions(ctx);
2849 
2850 	return 1;
2851 }
2852 
2853 /* d == last because each descriptor block is only a single descriptor. */
2854 static int handle_ir_buffer_fill(struct context *context,
2855 				 struct descriptor *d,
2856 				 struct descriptor *last)
2857 {
2858 	struct iso_context *ctx =
2859 		container_of(context, struct iso_context, context);
2860 	unsigned int req_count, res_count, completed;
2861 	u32 buffer_dma;
2862 
2863 	req_count = le16_to_cpu(last->req_count);
2864 	res_count = le16_to_cpu(READ_ONCE(last->res_count));
2865 	completed = req_count - res_count;
2866 	buffer_dma = le32_to_cpu(last->data_address);
2867 
2868 	if (completed > 0) {
2869 		ctx->mc_buffer_bus = buffer_dma;
2870 		ctx->mc_completed = completed;
2871 	}
2872 
2873 	if (res_count != 0)
2874 		/* Descriptor(s) not done yet, stop iteration */
2875 		return 0;
2876 
2877 	dma_sync_single_range_for_cpu(context->ohci->card.device,
2878 				      buffer_dma & PAGE_MASK,
2879 				      buffer_dma & ~PAGE_MASK,
2880 				      completed, DMA_FROM_DEVICE);
2881 
2882 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) {
2883 		ctx->base.callback.mc(&ctx->base,
2884 				      buffer_dma + completed,
2885 				      ctx->base.callback_data);
2886 		ctx->mc_completed = 0;
2887 	}
2888 
2889 	return 1;
2890 }
2891 
2892 static void flush_ir_buffer_fill(struct iso_context *ctx)
2893 {
2894 	dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
2895 				      ctx->mc_buffer_bus & PAGE_MASK,
2896 				      ctx->mc_buffer_bus & ~PAGE_MASK,
2897 				      ctx->mc_completed, DMA_FROM_DEVICE);
2898 
2899 	ctx->base.callback.mc(&ctx->base,
2900 			      ctx->mc_buffer_bus + ctx->mc_completed,
2901 			      ctx->base.callback_data);
2902 	ctx->mc_completed = 0;
2903 }
2904 
2905 static inline void sync_it_packet_for_cpu(struct context *context,
2906 					  struct descriptor *pd)
2907 {
2908 	__le16 control;
2909 	u32 buffer_dma;
2910 
2911 	/* only packets beginning with OUTPUT_MORE* have data buffers */
2912 	if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2913 		return;
2914 
2915 	/* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
2916 	pd += 2;
2917 
2918 	/*
2919 	 * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
2920 	 * data buffer is in the context program's coherent page and must not
2921 	 * be synced.
2922 	 */
2923 	if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
2924 	    (context->current_bus          & PAGE_MASK)) {
2925 		if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2926 			return;
2927 		pd++;
2928 	}
2929 
2930 	do {
2931 		buffer_dma = le32_to_cpu(pd->data_address);
2932 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2933 					      buffer_dma & PAGE_MASK,
2934 					      buffer_dma & ~PAGE_MASK,
2935 					      le16_to_cpu(pd->req_count),
2936 					      DMA_TO_DEVICE);
2937 		control = pd->control;
2938 		pd++;
2939 	} while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
2940 }
2941 
2942 static int handle_it_packet(struct context *context,
2943 			    struct descriptor *d,
2944 			    struct descriptor *last)
2945 {
2946 	struct iso_context *ctx =
2947 		container_of(context, struct iso_context, context);
2948 	struct descriptor *pd;
2949 	__be32 *ctx_hdr;
2950 
2951 	for (pd = d; pd <= last; pd++)
2952 		if (pd->transfer_status)
2953 			break;
2954 	if (pd > last)
2955 		/* Descriptor(s) not done yet, stop iteration */
2956 		return 0;
2957 
2958 	sync_it_packet_for_cpu(context, d);
2959 
2960 	if (ctx->header_length + 4 > PAGE_SIZE) {
2961 		if (ctx->base.drop_overflow_headers)
2962 			return 1;
2963 		flush_iso_completions(ctx);
2964 	}
2965 
2966 	ctx_hdr = ctx->header + ctx->header_length;
2967 	ctx->last_timestamp = le16_to_cpu(last->res_count);
2968 	/* Present this value as big-endian to match the receive code */
2969 	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
2970 			       le16_to_cpu(pd->res_count));
2971 	ctx->header_length += 4;
2972 
2973 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2974 		flush_iso_completions(ctx);
2975 
2976 	return 1;
2977 }
2978 
2979 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2980 {
2981 	u32 hi = channels >> 32, lo = channels;
2982 
2983 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2984 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2985 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2986 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2987 	ohci->mc_channels = channels;
2988 }
2989 
2990 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2991 				int type, int channel, size_t header_size)
2992 {
2993 	struct fw_ohci *ohci = fw_ohci(card);
2994 	struct iso_context *ctx;
2995 	descriptor_callback_t callback;
2996 	u64 *channels;
2997 	u32 *mask, regs;
2998 	int index, ret = -EBUSY;
2999 
3000 	spin_lock_irq(&ohci->lock);
3001 
3002 	switch (type) {
3003 	case FW_ISO_CONTEXT_TRANSMIT:
3004 		mask     = &ohci->it_context_mask;
3005 		callback = handle_it_packet;
3006 		index    = ffs(*mask) - 1;
3007 		if (index >= 0) {
3008 			*mask &= ~(1 << index);
3009 			regs = OHCI1394_IsoXmitContextBase(index);
3010 			ctx  = &ohci->it_context_list[index];
3011 		}
3012 		break;
3013 
3014 	case FW_ISO_CONTEXT_RECEIVE:
3015 		channels = &ohci->ir_context_channels;
3016 		mask     = &ohci->ir_context_mask;
3017 		callback = handle_ir_packet_per_buffer;
3018 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
3019 		if (index >= 0) {
3020 			*channels &= ~(1ULL << channel);
3021 			*mask     &= ~(1 << index);
3022 			regs = OHCI1394_IsoRcvContextBase(index);
3023 			ctx  = &ohci->ir_context_list[index];
3024 		}
3025 		break;
3026 
3027 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3028 		mask     = &ohci->ir_context_mask;
3029 		callback = handle_ir_buffer_fill;
3030 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
3031 		if (index >= 0) {
3032 			ohci->mc_allocated = true;
3033 			*mask &= ~(1 << index);
3034 			regs = OHCI1394_IsoRcvContextBase(index);
3035 			ctx  = &ohci->ir_context_list[index];
3036 		}
3037 		break;
3038 
3039 	default:
3040 		index = -1;
3041 		ret = -ENOSYS;
3042 	}
3043 
3044 	spin_unlock_irq(&ohci->lock);
3045 
3046 	if (index < 0)
3047 		return ERR_PTR(ret);
3048 
3049 	memset(ctx, 0, sizeof(*ctx));
3050 	ctx->header_length = 0;
3051 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
3052 	if (ctx->header == NULL) {
3053 		ret = -ENOMEM;
3054 		goto out;
3055 	}
3056 	ret = context_init(&ctx->context, ohci, regs, callback);
3057 	if (ret < 0)
3058 		goto out_with_header;
3059 
3060 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
3061 		set_multichannel_mask(ohci, 0);
3062 		ctx->mc_completed = 0;
3063 	}
3064 
3065 	return &ctx->base;
3066 
3067  out_with_header:
3068 	free_page((unsigned long)ctx->header);
3069  out:
3070 	spin_lock_irq(&ohci->lock);
3071 
3072 	switch (type) {
3073 	case FW_ISO_CONTEXT_RECEIVE:
3074 		*channels |= 1ULL << channel;
3075 		break;
3076 
3077 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3078 		ohci->mc_allocated = false;
3079 		break;
3080 	}
3081 	*mask |= 1 << index;
3082 
3083 	spin_unlock_irq(&ohci->lock);
3084 
3085 	return ERR_PTR(ret);
3086 }
3087 
3088 static int ohci_start_iso(struct fw_iso_context *base,
3089 			  s32 cycle, u32 sync, u32 tags)
3090 {
3091 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3092 	struct fw_ohci *ohci = ctx->context.ohci;
3093 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
3094 	int index;
3095 
3096 	/* the controller cannot start without any queued packets */
3097 	if (ctx->context.last->branch_address == 0)
3098 		return -ENODATA;
3099 
3100 	switch (ctx->base.type) {
3101 	case FW_ISO_CONTEXT_TRANSMIT:
3102 		index = ctx - ohci->it_context_list;
3103 		match = 0;
3104 		if (cycle >= 0)
3105 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
3106 				(cycle & 0x7fff) << 16;
3107 
3108 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
3109 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
3110 		context_run(&ctx->context, match);
3111 		break;
3112 
3113 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3114 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
3115 		fallthrough;
3116 	case FW_ISO_CONTEXT_RECEIVE:
3117 		index = ctx - ohci->ir_context_list;
3118 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
3119 		if (cycle >= 0) {
3120 			match |= (cycle & 0x07fff) << 12;
3121 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
3122 		}
3123 
3124 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
3125 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
3126 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
3127 		context_run(&ctx->context, control);
3128 
3129 		ctx->sync = sync;
3130 		ctx->tags = tags;
3131 
3132 		break;
3133 	}
3134 
3135 	return 0;
3136 }
3137 
3138 static int ohci_stop_iso(struct fw_iso_context *base)
3139 {
3140 	struct fw_ohci *ohci = fw_ohci(base->card);
3141 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3142 	int index;
3143 
3144 	switch (ctx->base.type) {
3145 	case FW_ISO_CONTEXT_TRANSMIT:
3146 		index = ctx - ohci->it_context_list;
3147 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
3148 		break;
3149 
3150 	case FW_ISO_CONTEXT_RECEIVE:
3151 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3152 		index = ctx - ohci->ir_context_list;
3153 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
3154 		break;
3155 	}
3156 	flush_writes(ohci);
3157 	context_stop(&ctx->context);
3158 	tasklet_kill(&ctx->context.tasklet);
3159 
3160 	return 0;
3161 }
3162 
3163 static void ohci_free_iso_context(struct fw_iso_context *base)
3164 {
3165 	struct fw_ohci *ohci = fw_ohci(base->card);
3166 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3167 	unsigned long flags;
3168 	int index;
3169 
3170 	ohci_stop_iso(base);
3171 	context_release(&ctx->context);
3172 	free_page((unsigned long)ctx->header);
3173 
3174 	spin_lock_irqsave(&ohci->lock, flags);
3175 
3176 	switch (base->type) {
3177 	case FW_ISO_CONTEXT_TRANSMIT:
3178 		index = ctx - ohci->it_context_list;
3179 		ohci->it_context_mask |= 1 << index;
3180 		break;
3181 
3182 	case FW_ISO_CONTEXT_RECEIVE:
3183 		index = ctx - ohci->ir_context_list;
3184 		ohci->ir_context_mask |= 1 << index;
3185 		ohci->ir_context_channels |= 1ULL << base->channel;
3186 		break;
3187 
3188 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3189 		index = ctx - ohci->ir_context_list;
3190 		ohci->ir_context_mask |= 1 << index;
3191 		ohci->ir_context_channels |= ohci->mc_channels;
3192 		ohci->mc_channels = 0;
3193 		ohci->mc_allocated = false;
3194 		break;
3195 	}
3196 
3197 	spin_unlock_irqrestore(&ohci->lock, flags);
3198 }
3199 
3200 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
3201 {
3202 	struct fw_ohci *ohci = fw_ohci(base->card);
3203 	unsigned long flags;
3204 	int ret;
3205 
3206 	switch (base->type) {
3207 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3208 
3209 		spin_lock_irqsave(&ohci->lock, flags);
3210 
3211 		/* Don't allow multichannel to grab other contexts' channels. */
3212 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
3213 			*channels = ohci->ir_context_channels;
3214 			ret = -EBUSY;
3215 		} else {
3216 			set_multichannel_mask(ohci, *channels);
3217 			ret = 0;
3218 		}
3219 
3220 		spin_unlock_irqrestore(&ohci->lock, flags);
3221 
3222 		break;
3223 	default:
3224 		ret = -EINVAL;
3225 	}
3226 
3227 	return ret;
3228 }
3229 
3230 #ifdef CONFIG_PM
3231 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
3232 {
3233 	int i;
3234 	struct iso_context *ctx;
3235 
3236 	for (i = 0 ; i < ohci->n_ir ; i++) {
3237 		ctx = &ohci->ir_context_list[i];
3238 		if (ctx->context.running)
3239 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3240 	}
3241 
3242 	for (i = 0 ; i < ohci->n_it ; i++) {
3243 		ctx = &ohci->it_context_list[i];
3244 		if (ctx->context.running)
3245 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3246 	}
3247 }
3248 #endif
3249 
3250 static int queue_iso_transmit(struct iso_context *ctx,
3251 			      struct fw_iso_packet *packet,
3252 			      struct fw_iso_buffer *buffer,
3253 			      unsigned long payload)
3254 {
3255 	struct descriptor *d, *last, *pd;
3256 	struct fw_iso_packet *p;
3257 	__le32 *header;
3258 	dma_addr_t d_bus, page_bus;
3259 	u32 z, header_z, payload_z, irq;
3260 	u32 payload_index, payload_end_index, next_page_index;
3261 	int page, end_page, i, length, offset;
3262 
3263 	p = packet;
3264 	payload_index = payload;
3265 
3266 	if (p->skip)
3267 		z = 1;
3268 	else
3269 		z = 2;
3270 	if (p->header_length > 0)
3271 		z++;
3272 
3273 	/* Determine the first page the payload isn't contained in. */
3274 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
3275 	if (p->payload_length > 0)
3276 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
3277 	else
3278 		payload_z = 0;
3279 
3280 	z += payload_z;
3281 
3282 	/* Get header size in number of descriptors. */
3283 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
3284 
3285 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
3286 	if (d == NULL)
3287 		return -ENOMEM;
3288 
3289 	if (!p->skip) {
3290 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
3291 		d[0].req_count = cpu_to_le16(8);
3292 		/*
3293 		 * Link the skip address to this descriptor itself.  This causes
3294 		 * a context to skip a cycle whenever lost cycles or FIFO
3295 		 * overruns occur, without dropping the data.  The application
3296 		 * should then decide whether this is an error condition or not.
3297 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
3298 		 */
3299 		d[0].branch_address = cpu_to_le32(d_bus | z);
3300 
3301 		header = (__le32 *) &d[1];
3302 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
3303 					IT_HEADER_TAG(p->tag) |
3304 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
3305 					IT_HEADER_CHANNEL(ctx->base.channel) |
3306 					IT_HEADER_SPEED(ctx->base.speed));
3307 		header[1] =
3308 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
3309 							  p->payload_length));
3310 	}
3311 
3312 	if (p->header_length > 0) {
3313 		d[2].req_count    = cpu_to_le16(p->header_length);
3314 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
3315 		memcpy(&d[z], p->header, p->header_length);
3316 	}
3317 
3318 	pd = d + z - payload_z;
3319 	payload_end_index = payload_index + p->payload_length;
3320 	for (i = 0; i < payload_z; i++) {
3321 		page               = payload_index >> PAGE_SHIFT;
3322 		offset             = payload_index & ~PAGE_MASK;
3323 		next_page_index    = (page + 1) << PAGE_SHIFT;
3324 		length             =
3325 			min(next_page_index, payload_end_index) - payload_index;
3326 		pd[i].req_count    = cpu_to_le16(length);
3327 
3328 		page_bus = page_private(buffer->pages[page]);
3329 		pd[i].data_address = cpu_to_le32(page_bus + offset);
3330 
3331 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3332 						 page_bus, offset, length,
3333 						 DMA_TO_DEVICE);
3334 
3335 		payload_index += length;
3336 	}
3337 
3338 	if (p->interrupt)
3339 		irq = DESCRIPTOR_IRQ_ALWAYS;
3340 	else
3341 		irq = DESCRIPTOR_NO_IRQ;
3342 
3343 	last = z == 2 ? d : d + z - 1;
3344 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
3345 				     DESCRIPTOR_STATUS |
3346 				     DESCRIPTOR_BRANCH_ALWAYS |
3347 				     irq);
3348 
3349 	context_append(&ctx->context, d, z, header_z);
3350 
3351 	return 0;
3352 }
3353 
3354 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
3355 				       struct fw_iso_packet *packet,
3356 				       struct fw_iso_buffer *buffer,
3357 				       unsigned long payload)
3358 {
3359 	struct device *device = ctx->context.ohci->card.device;
3360 	struct descriptor *d, *pd;
3361 	dma_addr_t d_bus, page_bus;
3362 	u32 z, header_z, rest;
3363 	int i, j, length;
3364 	int page, offset, packet_count, header_size, payload_per_buffer;
3365 
3366 	/*
3367 	 * The OHCI controller puts the isochronous header and trailer in the
3368 	 * buffer, so we need at least 8 bytes.
3369 	 */
3370 	packet_count = packet->header_length / ctx->base.header_size;
3371 	header_size  = max(ctx->base.header_size, (size_t)8);
3372 
3373 	/* Get header size in number of descriptors. */
3374 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
3375 	page     = payload >> PAGE_SHIFT;
3376 	offset   = payload & ~PAGE_MASK;
3377 	payload_per_buffer = packet->payload_length / packet_count;
3378 
3379 	for (i = 0; i < packet_count; i++) {
3380 		/* d points to the header descriptor */
3381 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
3382 		d = context_get_descriptors(&ctx->context,
3383 				z + header_z, &d_bus);
3384 		if (d == NULL)
3385 			return -ENOMEM;
3386 
3387 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3388 					      DESCRIPTOR_INPUT_MORE);
3389 		if (packet->skip && i == 0)
3390 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3391 		d->req_count    = cpu_to_le16(header_size);
3392 		d->res_count    = d->req_count;
3393 		d->transfer_status = 0;
3394 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3395 
3396 		rest = payload_per_buffer;
3397 		pd = d;
3398 		for (j = 1; j < z; j++) {
3399 			pd++;
3400 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3401 						  DESCRIPTOR_INPUT_MORE);
3402 
3403 			if (offset + rest < PAGE_SIZE)
3404 				length = rest;
3405 			else
3406 				length = PAGE_SIZE - offset;
3407 			pd->req_count = cpu_to_le16(length);
3408 			pd->res_count = pd->req_count;
3409 			pd->transfer_status = 0;
3410 
3411 			page_bus = page_private(buffer->pages[page]);
3412 			pd->data_address = cpu_to_le32(page_bus + offset);
3413 
3414 			dma_sync_single_range_for_device(device, page_bus,
3415 							 offset, length,
3416 							 DMA_FROM_DEVICE);
3417 
3418 			offset = (offset + length) & ~PAGE_MASK;
3419 			rest -= length;
3420 			if (offset == 0)
3421 				page++;
3422 		}
3423 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3424 					  DESCRIPTOR_INPUT_LAST |
3425 					  DESCRIPTOR_BRANCH_ALWAYS);
3426 		if (packet->interrupt && i == packet_count - 1)
3427 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3428 
3429 		context_append(&ctx->context, d, z, header_z);
3430 	}
3431 
3432 	return 0;
3433 }
3434 
3435 static int queue_iso_buffer_fill(struct iso_context *ctx,
3436 				 struct fw_iso_packet *packet,
3437 				 struct fw_iso_buffer *buffer,
3438 				 unsigned long payload)
3439 {
3440 	struct descriptor *d;
3441 	dma_addr_t d_bus, page_bus;
3442 	int page, offset, rest, z, i, length;
3443 
3444 	page   = payload >> PAGE_SHIFT;
3445 	offset = payload & ~PAGE_MASK;
3446 	rest   = packet->payload_length;
3447 
3448 	/* We need one descriptor for each page in the buffer. */
3449 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3450 
3451 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3452 		return -EFAULT;
3453 
3454 	for (i = 0; i < z; i++) {
3455 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3456 		if (d == NULL)
3457 			return -ENOMEM;
3458 
3459 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3460 					 DESCRIPTOR_BRANCH_ALWAYS);
3461 		if (packet->skip && i == 0)
3462 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3463 		if (packet->interrupt && i == z - 1)
3464 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3465 
3466 		if (offset + rest < PAGE_SIZE)
3467 			length = rest;
3468 		else
3469 			length = PAGE_SIZE - offset;
3470 		d->req_count = cpu_to_le16(length);
3471 		d->res_count = d->req_count;
3472 		d->transfer_status = 0;
3473 
3474 		page_bus = page_private(buffer->pages[page]);
3475 		d->data_address = cpu_to_le32(page_bus + offset);
3476 
3477 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3478 						 page_bus, offset, length,
3479 						 DMA_FROM_DEVICE);
3480 
3481 		rest -= length;
3482 		offset = 0;
3483 		page++;
3484 
3485 		context_append(&ctx->context, d, 1, 0);
3486 	}
3487 
3488 	return 0;
3489 }
3490 
3491 static int ohci_queue_iso(struct fw_iso_context *base,
3492 			  struct fw_iso_packet *packet,
3493 			  struct fw_iso_buffer *buffer,
3494 			  unsigned long payload)
3495 {
3496 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3497 	unsigned long flags;
3498 	int ret = -ENOSYS;
3499 
3500 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3501 	switch (base->type) {
3502 	case FW_ISO_CONTEXT_TRANSMIT:
3503 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3504 		break;
3505 	case FW_ISO_CONTEXT_RECEIVE:
3506 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3507 		break;
3508 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3509 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3510 		break;
3511 	}
3512 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3513 
3514 	return ret;
3515 }
3516 
3517 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3518 {
3519 	struct context *ctx =
3520 			&container_of(base, struct iso_context, base)->context;
3521 
3522 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3523 }
3524 
3525 static int ohci_flush_iso_completions(struct fw_iso_context *base)
3526 {
3527 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3528 	int ret = 0;
3529 
3530 	tasklet_disable_in_atomic(&ctx->context.tasklet);
3531 
3532 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
3533 		context_tasklet((unsigned long)&ctx->context);
3534 
3535 		switch (base->type) {
3536 		case FW_ISO_CONTEXT_TRANSMIT:
3537 		case FW_ISO_CONTEXT_RECEIVE:
3538 			if (ctx->header_length != 0)
3539 				flush_iso_completions(ctx);
3540 			break;
3541 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3542 			if (ctx->mc_completed != 0)
3543 				flush_ir_buffer_fill(ctx);
3544 			break;
3545 		default:
3546 			ret = -ENOSYS;
3547 		}
3548 
3549 		clear_bit_unlock(0, &ctx->flushing_completions);
3550 		smp_mb__after_atomic();
3551 	}
3552 
3553 	tasklet_enable(&ctx->context.tasklet);
3554 
3555 	return ret;
3556 }
3557 
3558 static const struct fw_card_driver ohci_driver = {
3559 	.enable			= ohci_enable,
3560 	.read_phy_reg		= ohci_read_phy_reg,
3561 	.update_phy_reg		= ohci_update_phy_reg,
3562 	.set_config_rom		= ohci_set_config_rom,
3563 	.send_request		= ohci_send_request,
3564 	.send_response		= ohci_send_response,
3565 	.cancel_packet		= ohci_cancel_packet,
3566 	.enable_phys_dma	= ohci_enable_phys_dma,
3567 	.read_csr		= ohci_read_csr,
3568 	.write_csr		= ohci_write_csr,
3569 
3570 	.allocate_iso_context	= ohci_allocate_iso_context,
3571 	.free_iso_context	= ohci_free_iso_context,
3572 	.set_iso_channels	= ohci_set_iso_channels,
3573 	.queue_iso		= ohci_queue_iso,
3574 	.flush_queue_iso	= ohci_flush_queue_iso,
3575 	.flush_iso_completions	= ohci_flush_iso_completions,
3576 	.start_iso		= ohci_start_iso,
3577 	.stop_iso		= ohci_stop_iso,
3578 };
3579 
3580 #ifdef CONFIG_PPC_PMAC
3581 static void pmac_ohci_on(struct pci_dev *dev)
3582 {
3583 	if (machine_is(powermac)) {
3584 		struct device_node *ofn = pci_device_to_OF_node(dev);
3585 
3586 		if (ofn) {
3587 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3588 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3589 		}
3590 	}
3591 }
3592 
3593 static void pmac_ohci_off(struct pci_dev *dev)
3594 {
3595 	if (machine_is(powermac)) {
3596 		struct device_node *ofn = pci_device_to_OF_node(dev);
3597 
3598 		if (ofn) {
3599 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3600 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3601 		}
3602 	}
3603 }
3604 #else
3605 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3606 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3607 #endif /* CONFIG_PPC_PMAC */
3608 
3609 static void release_ohci(struct device *dev, void *data)
3610 {
3611 	struct pci_dev *pdev = to_pci_dev(dev);
3612 	struct fw_ohci *ohci = pci_get_drvdata(pdev);
3613 
3614 	pmac_ohci_off(pdev);
3615 
3616 	ar_context_release(&ohci->ar_response_ctx);
3617 	ar_context_release(&ohci->ar_request_ctx);
3618 
3619 	dev_notice(dev, "removed fw-ohci device\n");
3620 }
3621 
3622 static int pci_probe(struct pci_dev *dev,
3623 			       const struct pci_device_id *ent)
3624 {
3625 	struct fw_ohci *ohci;
3626 	u32 bus_options, max_receive, link_speed, version;
3627 	u64 guid;
3628 	int i, flags, irq, err;
3629 	size_t size;
3630 
3631 	if (dev->vendor == PCI_VENDOR_ID_PINNACLE_SYSTEMS) {
3632 		dev_err(&dev->dev, "Pinnacle MovieBoard is not yet supported\n");
3633 		return -ENOSYS;
3634 	}
3635 
3636 	ohci = devres_alloc(release_ohci, sizeof(*ohci), GFP_KERNEL);
3637 	if (ohci == NULL)
3638 		return -ENOMEM;
3639 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3640 	pci_set_drvdata(dev, ohci);
3641 	pmac_ohci_on(dev);
3642 	devres_add(&dev->dev, ohci);
3643 
3644 	err = pcim_enable_device(dev);
3645 	if (err) {
3646 		dev_err(&dev->dev, "failed to enable OHCI hardware\n");
3647 		return err;
3648 	}
3649 
3650 	pci_set_master(dev);
3651 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3652 
3653 	spin_lock_init(&ohci->lock);
3654 	mutex_init(&ohci->phy_reg_mutex);
3655 
3656 	INIT_WORK(&ohci->bus_reset_work, bus_reset_work);
3657 
3658 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM) ||
3659 	    pci_resource_len(dev, 0) < OHCI1394_REGISTER_SIZE) {
3660 		ohci_err(ohci, "invalid MMIO resource\n");
3661 		return -ENXIO;
3662 	}
3663 
3664 	err = pcim_iomap_regions(dev, 1 << 0, ohci_driver_name);
3665 	if (err) {
3666 		ohci_err(ohci, "request and map MMIO resource unavailable\n");
3667 		return -ENXIO;
3668 	}
3669 	ohci->registers = pcim_iomap_table(dev)[0];
3670 
3671 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3672 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3673 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3674 		     ohci_quirks[i].device == dev->device) &&
3675 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3676 		     ohci_quirks[i].revision >= dev->revision)) {
3677 			ohci->quirks = ohci_quirks[i].flags;
3678 			break;
3679 		}
3680 	if (param_quirks)
3681 		ohci->quirks = param_quirks;
3682 
3683 	if (detect_vt630x_with_asm1083_on_amd_ryzen_machine(dev))
3684 		ohci->quirks |= QUIRK_REBOOT_BY_CYCLE_TIMER_READ;
3685 
3686 	/*
3687 	 * Because dma_alloc_coherent() allocates at least one page,
3688 	 * we save space by using a common buffer for the AR request/
3689 	 * response descriptors and the self IDs buffer.
3690 	 */
3691 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3692 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3693 	ohci->misc_buffer = dmam_alloc_coherent(&dev->dev, PAGE_SIZE, &ohci->misc_buffer_bus,
3694 						GFP_KERNEL);
3695 	if (!ohci->misc_buffer)
3696 		return -ENOMEM;
3697 
3698 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3699 			      OHCI1394_AsReqRcvContextControlSet);
3700 	if (err < 0)
3701 		return err;
3702 
3703 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3704 			      OHCI1394_AsRspRcvContextControlSet);
3705 	if (err < 0)
3706 		return err;
3707 
3708 	err = context_init(&ohci->at_request_ctx, ohci,
3709 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3710 	if (err < 0)
3711 		return err;
3712 
3713 	err = context_init(&ohci->at_response_ctx, ohci,
3714 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3715 	if (err < 0)
3716 		return err;
3717 
3718 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3719 	ohci->ir_context_channels = ~0ULL;
3720 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3721 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3722 	ohci->ir_context_mask = ohci->ir_context_support;
3723 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3724 	size = sizeof(struct iso_context) * ohci->n_ir;
3725 	ohci->ir_context_list = devm_kzalloc(&dev->dev, size, GFP_KERNEL);
3726 	if (!ohci->ir_context_list)
3727 		return -ENOMEM;
3728 
3729 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3730 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3731 	/* JMicron JMB38x often shows 0 at first read, just ignore it */
3732 	if (!ohci->it_context_support) {
3733 		ohci_notice(ohci, "overriding IsoXmitIntMask\n");
3734 		ohci->it_context_support = 0xf;
3735 	}
3736 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3737 	ohci->it_context_mask = ohci->it_context_support;
3738 	ohci->n_it = hweight32(ohci->it_context_mask);
3739 	size = sizeof(struct iso_context) * ohci->n_it;
3740 	ohci->it_context_list = devm_kzalloc(&dev->dev, size, GFP_KERNEL);
3741 	if (!ohci->it_context_list)
3742 		return -ENOMEM;
3743 
3744 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
3745 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3746 
3747 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3748 	max_receive = (bus_options >> 12) & 0xf;
3749 	link_speed = bus_options & 0x7;
3750 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3751 		reg_read(ohci, OHCI1394_GUIDLo);
3752 
3753 	flags = PCI_IRQ_INTX;
3754 	if (!(ohci->quirks & QUIRK_NO_MSI))
3755 		flags |= PCI_IRQ_MSI;
3756 	err = pci_alloc_irq_vectors(dev, 1, 1, flags);
3757 	if (err < 0)
3758 		return err;
3759 	irq = pci_irq_vector(dev, 0);
3760 	if (irq < 0) {
3761 		err = irq;
3762 		goto fail_msi;
3763 	}
3764 
3765 	err = request_threaded_irq(irq, irq_handler, NULL,
3766 				   pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED, ohci_driver_name,
3767 				   ohci);
3768 	if (err < 0) {
3769 		ohci_err(ohci, "failed to allocate interrupt %d\n", irq);
3770 		goto fail_msi;
3771 	}
3772 
3773 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3774 	if (err)
3775 		goto fail_irq;
3776 
3777 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3778 	ohci_notice(ohci,
3779 		    "added OHCI v%x.%x device as card %d, "
3780 		    "%d IR + %d IT contexts, quirks 0x%x%s\n",
3781 		    version >> 16, version & 0xff, ohci->card.index,
3782 		    ohci->n_ir, ohci->n_it, ohci->quirks,
3783 		    reg_read(ohci, OHCI1394_PhyUpperBound) ?
3784 			", physUB" : "");
3785 
3786 	return 0;
3787 
3788  fail_irq:
3789 	free_irq(irq, ohci);
3790  fail_msi:
3791 	pci_free_irq_vectors(dev);
3792 
3793 	return err;
3794 }
3795 
3796 static void pci_remove(struct pci_dev *dev)
3797 {
3798 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3799 	int irq;
3800 
3801 	/*
3802 	 * If the removal is happening from the suspend state, LPS won't be
3803 	 * enabled and host registers (eg., IntMaskClear) won't be accessible.
3804 	 */
3805 	if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) {
3806 		reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3807 		flush_writes(ohci);
3808 	}
3809 	cancel_work_sync(&ohci->bus_reset_work);
3810 	fw_core_remove_card(&ohci->card);
3811 
3812 	/*
3813 	 * FIXME: Fail all pending packets here, now that the upper
3814 	 * layers can't queue any more.
3815 	 */
3816 
3817 	software_reset(ohci);
3818 
3819 	irq = pci_irq_vector(dev, 0);
3820 	if (irq >= 0)
3821 		free_irq(irq, ohci);
3822 	pci_free_irq_vectors(dev);
3823 
3824 	dev_notice(&dev->dev, "removing fw-ohci device\n");
3825 }
3826 
3827 #ifdef CONFIG_PM
3828 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3829 {
3830 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3831 	int err;
3832 
3833 	software_reset(ohci);
3834 	err = pci_save_state(dev);
3835 	if (err) {
3836 		ohci_err(ohci, "pci_save_state failed\n");
3837 		return err;
3838 	}
3839 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3840 	if (err)
3841 		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
3842 	pmac_ohci_off(dev);
3843 
3844 	return 0;
3845 }
3846 
3847 static int pci_resume(struct pci_dev *dev)
3848 {
3849 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3850 	int err;
3851 
3852 	pmac_ohci_on(dev);
3853 	pci_set_power_state(dev, PCI_D0);
3854 	pci_restore_state(dev);
3855 	err = pci_enable_device(dev);
3856 	if (err) {
3857 		ohci_err(ohci, "pci_enable_device failed\n");
3858 		return err;
3859 	}
3860 
3861 	/* Some systems don't setup GUID register on resume from ram  */
3862 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3863 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3864 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3865 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3866 	}
3867 
3868 	err = ohci_enable(&ohci->card, NULL, 0);
3869 	if (err)
3870 		return err;
3871 
3872 	ohci_resume_iso_dma(ohci);
3873 
3874 	return 0;
3875 }
3876 #endif
3877 
3878 static const struct pci_device_id pci_table[] = {
3879 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3880 	{ }
3881 };
3882 
3883 MODULE_DEVICE_TABLE(pci, pci_table);
3884 
3885 static struct pci_driver fw_ohci_pci_driver = {
3886 	.name		= ohci_driver_name,
3887 	.id_table	= pci_table,
3888 	.probe		= pci_probe,
3889 	.remove		= pci_remove,
3890 #ifdef CONFIG_PM
3891 	.resume		= pci_resume,
3892 	.suspend	= pci_suspend,
3893 #endif
3894 };
3895 
3896 static int __init fw_ohci_init(void)
3897 {
3898 	selfid_workqueue = alloc_workqueue(KBUILD_MODNAME, WQ_MEM_RECLAIM, 0);
3899 	if (!selfid_workqueue)
3900 		return -ENOMEM;
3901 
3902 	return pci_register_driver(&fw_ohci_pci_driver);
3903 }
3904 
3905 static void __exit fw_ohci_cleanup(void)
3906 {
3907 	pci_unregister_driver(&fw_ohci_pci_driver);
3908 	destroy_workqueue(selfid_workqueue);
3909 }
3910 
3911 module_init(fw_ohci_init);
3912 module_exit(fw_ohci_cleanup);
3913 
3914 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3915 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3916 MODULE_LICENSE("GPL");
3917 
3918 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3919 MODULE_ALIAS("ohci1394");
3920