xref: /linux/drivers/firewire/ohci.c (revision 9e56ff53b4115875667760445b028357848b4748)
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 
44 #define ohci_info(ohci, f, args...)	dev_info(ohci->card.device, f, ##args)
45 #define ohci_notice(ohci, f, args...)	dev_notice(ohci->card.device, f, ##args)
46 #define ohci_err(ohci, f, args...)	dev_err(ohci->card.device, f, ##args)
47 
48 #define DESCRIPTOR_OUTPUT_MORE		0
49 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
50 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
51 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
52 #define DESCRIPTOR_STATUS		(1 << 11)
53 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
54 #define DESCRIPTOR_PING			(1 << 7)
55 #define DESCRIPTOR_YY			(1 << 6)
56 #define DESCRIPTOR_NO_IRQ		(0 << 4)
57 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
58 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
59 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
60 #define DESCRIPTOR_WAIT			(3 << 0)
61 
62 #define DESCRIPTOR_CMD			(0xf << 12)
63 
64 struct descriptor {
65 	__le16 req_count;
66 	__le16 control;
67 	__le32 data_address;
68 	__le32 branch_address;
69 	__le16 res_count;
70 	__le16 transfer_status;
71 } __attribute__((aligned(16)));
72 
73 #define CONTROL_SET(regs)	(regs)
74 #define CONTROL_CLEAR(regs)	((regs) + 4)
75 #define COMMAND_PTR(regs)	((regs) + 12)
76 #define CONTEXT_MATCH(regs)	((regs) + 16)
77 
78 #define AR_BUFFER_SIZE	(32*1024)
79 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
80 /* we need at least two pages for proper list management */
81 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
82 
83 #define MAX_ASYNC_PAYLOAD	4096
84 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
85 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
86 
87 struct ar_context {
88 	struct fw_ohci *ohci;
89 	struct page *pages[AR_BUFFERS];
90 	void *buffer;
91 	struct descriptor *descriptors;
92 	dma_addr_t descriptors_bus;
93 	void *pointer;
94 	unsigned int last_buffer_index;
95 	u32 regs;
96 	struct tasklet_struct tasklet;
97 };
98 
99 struct context;
100 
101 typedef int (*descriptor_callback_t)(struct context *ctx,
102 				     struct descriptor *d,
103 				     struct descriptor *last);
104 
105 /*
106  * A buffer that contains a block of DMA-able coherent memory used for
107  * storing a portion of a DMA descriptor program.
108  */
109 struct descriptor_buffer {
110 	struct list_head list;
111 	dma_addr_t buffer_bus;
112 	size_t buffer_size;
113 	size_t used;
114 	struct descriptor buffer[];
115 };
116 
117 struct context {
118 	struct fw_ohci *ohci;
119 	u32 regs;
120 	int total_allocation;
121 	u32 current_bus;
122 	bool running;
123 	bool flushing;
124 
125 	/*
126 	 * List of page-sized buffers for storing DMA descriptors.
127 	 * Head of list contains buffers in use and tail of list contains
128 	 * free buffers.
129 	 */
130 	struct list_head buffer_list;
131 
132 	/*
133 	 * Pointer to a buffer inside buffer_list that contains the tail
134 	 * end of the current DMA program.
135 	 */
136 	struct descriptor_buffer *buffer_tail;
137 
138 	/*
139 	 * The descriptor containing the branch address of the first
140 	 * descriptor that has not yet been filled by the device.
141 	 */
142 	struct descriptor *last;
143 
144 	/*
145 	 * The last descriptor block in the DMA program. It contains the branch
146 	 * address that must be updated upon appending a new descriptor.
147 	 */
148 	struct descriptor *prev;
149 	int prev_z;
150 
151 	descriptor_callback_t callback;
152 
153 	struct tasklet_struct tasklet;
154 };
155 
156 #define IT_HEADER_SY(v)          ((v) <<  0)
157 #define IT_HEADER_TCODE(v)       ((v) <<  4)
158 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
159 #define IT_HEADER_TAG(v)         ((v) << 14)
160 #define IT_HEADER_SPEED(v)       ((v) << 16)
161 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
162 
163 struct iso_context {
164 	struct fw_iso_context base;
165 	struct context context;
166 	void *header;
167 	size_t header_length;
168 	unsigned long flushing_completions;
169 	u32 mc_buffer_bus;
170 	u16 mc_completed;
171 	u16 last_timestamp;
172 	u8 sync;
173 	u8 tags;
174 };
175 
176 #define CONFIG_ROM_SIZE 1024
177 
178 struct fw_ohci {
179 	struct fw_card card;
180 
181 	__iomem char *registers;
182 	int node_id;
183 	int generation;
184 	int request_generation;	/* for timestamping incoming requests */
185 	unsigned quirks;
186 	unsigned int pri_req_max;
187 	u32 bus_time;
188 	bool bus_time_running;
189 	bool is_root;
190 	bool csr_state_setclear_abdicate;
191 	int n_ir;
192 	int n_it;
193 	/*
194 	 * Spinlock for accessing fw_ohci data.  Never call out of
195 	 * this driver with this lock held.
196 	 */
197 	spinlock_t lock;
198 
199 	struct mutex phy_reg_mutex;
200 
201 	void *misc_buffer;
202 	dma_addr_t misc_buffer_bus;
203 
204 	struct ar_context ar_request_ctx;
205 	struct ar_context ar_response_ctx;
206 	struct context at_request_ctx;
207 	struct context at_response_ctx;
208 
209 	u32 it_context_support;
210 	u32 it_context_mask;     /* unoccupied IT contexts */
211 	struct iso_context *it_context_list;
212 	u64 ir_context_channels; /* unoccupied channels */
213 	u32 ir_context_support;
214 	u32 ir_context_mask;     /* unoccupied IR contexts */
215 	struct iso_context *ir_context_list;
216 	u64 mc_channels; /* channels in use by the multichannel IR context */
217 	bool mc_allocated;
218 
219 	__be32    *config_rom;
220 	dma_addr_t config_rom_bus;
221 	__be32    *next_config_rom;
222 	dma_addr_t next_config_rom_bus;
223 	__be32     next_header;
224 
225 	__le32    *self_id;
226 	dma_addr_t self_id_bus;
227 	struct work_struct bus_reset_work;
228 
229 	u32 self_id_buffer[512];
230 };
231 
232 static struct workqueue_struct *selfid_workqueue;
233 
234 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
235 {
236 	return container_of(card, struct fw_ohci, card);
237 }
238 
239 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
240 #define IR_CONTEXT_BUFFER_FILL		0x80000000
241 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
242 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
243 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
244 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
245 
246 #define CONTEXT_RUN	0x8000
247 #define CONTEXT_WAKE	0x1000
248 #define CONTEXT_DEAD	0x0800
249 #define CONTEXT_ACTIVE	0x0400
250 
251 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
252 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
253 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
254 
255 #define OHCI1394_REGISTER_SIZE		0x800
256 #define OHCI1394_PCI_HCI_Control	0x40
257 #define SELF_ID_BUF_SIZE		0x800
258 #define OHCI_TCODE_PHY_PACKET		0x0e
259 #define OHCI_VERSION_1_1		0x010010
260 
261 static char ohci_driver_name[] = KBUILD_MODNAME;
262 
263 #define PCI_VENDOR_ID_PINNACLE_SYSTEMS	0x11bd
264 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
265 #define PCI_DEVICE_ID_CREATIVE_SB1394	0x4001
266 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
267 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
268 #define PCI_DEVICE_ID_TI_TSB12LV26	0x8020
269 #define PCI_DEVICE_ID_TI_TSB82AA2	0x8025
270 #define PCI_DEVICE_ID_VIA_VT630X	0x3044
271 #define PCI_REV_ID_VIA_VT6306		0x46
272 #define PCI_DEVICE_ID_VIA_VT6315	0x3403
273 
274 #define QUIRK_CYCLE_TIMER		0x1
275 #define QUIRK_RESET_PACKET		0x2
276 #define QUIRK_BE_HEADERS		0x4
277 #define QUIRK_NO_1394A			0x8
278 #define QUIRK_NO_MSI			0x10
279 #define QUIRK_TI_SLLZ059		0x20
280 #define QUIRK_IR_WAKE			0x40
281 
282 // On PCI Express Root Complex in any type of AMD Ryzen machine, VIA VT6306/6307/6308 with Asmedia
283 // ASM1083/1085 brings an inconvenience that the read accesses to 'Isochronous Cycle Timer' register
284 // (at offset 0xf0 in PCI I/O space) often causes unexpected system reboot. The mechanism is not
285 // clear, since the read access to the other registers is enough safe; e.g. 'Node ID' register,
286 // while it is probable due to detection of any type of PCIe error.
287 #define QUIRK_REBOOT_BY_CYCLE_TIMER_READ	0x80000000
288 
289 #if IS_ENABLED(CONFIG_X86)
290 
291 static bool has_reboot_by_cycle_timer_read_quirk(const struct fw_ohci *ohci)
292 {
293 	return !!(ohci->quirks & QUIRK_REBOOT_BY_CYCLE_TIMER_READ);
294 }
295 
296 #define PCI_DEVICE_ID_ASMEDIA_ASM108X	0x1080
297 
298 static bool detect_vt630x_with_asm1083_on_amd_ryzen_machine(const struct pci_dev *pdev)
299 {
300 	const struct pci_dev *pcie_to_pci_bridge;
301 
302 	// Detect any type of AMD Ryzen machine.
303 	if (!static_cpu_has(X86_FEATURE_ZEN))
304 		return false;
305 
306 	// Detect VIA VT6306/6307/6308.
307 	if (pdev->vendor != PCI_VENDOR_ID_VIA)
308 		return false;
309 	if (pdev->device != PCI_DEVICE_ID_VIA_VT630X)
310 		return false;
311 
312 	// Detect Asmedia ASM1083/1085.
313 	pcie_to_pci_bridge = pdev->bus->self;
314 	if (pcie_to_pci_bridge->vendor != PCI_VENDOR_ID_ASMEDIA)
315 		return false;
316 	if (pcie_to_pci_bridge->device != PCI_DEVICE_ID_ASMEDIA_ASM108X)
317 		return false;
318 
319 	return true;
320 }
321 
322 #else
323 #define has_reboot_by_cycle_timer_read_quirk(ohci) false
324 #define detect_vt630x_with_asm1083_on_amd_ryzen_machine(pdev)	false
325 #endif
326 
327 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
328 static const struct {
329 	unsigned short vendor, device, revision, flags;
330 } ohci_quirks[] = {
331 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
332 		QUIRK_CYCLE_TIMER},
333 
334 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
335 		QUIRK_BE_HEADERS},
336 
337 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
338 		QUIRK_NO_MSI},
339 
340 	{PCI_VENDOR_ID_CREATIVE, PCI_DEVICE_ID_CREATIVE_SB1394, PCI_ANY_ID,
341 		QUIRK_RESET_PACKET},
342 
343 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
344 		QUIRK_NO_MSI},
345 
346 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
347 		QUIRK_CYCLE_TIMER},
348 
349 	{PCI_VENDOR_ID_O2, PCI_ANY_ID, PCI_ANY_ID,
350 		QUIRK_NO_MSI},
351 
352 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
353 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
354 
355 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
356 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
357 
358 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV26, PCI_ANY_ID,
359 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
360 
361 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB82AA2, PCI_ANY_ID,
362 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
363 
364 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
365 		QUIRK_RESET_PACKET},
366 
367 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT630X, PCI_REV_ID_VIA_VT6306,
368 		QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE},
369 
370 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, 0,
371 		QUIRK_CYCLE_TIMER /* FIXME: necessary? */ | QUIRK_NO_MSI},
372 
373 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, PCI_ANY_ID,
374 		QUIRK_NO_MSI},
375 
376 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
377 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
378 };
379 
380 /* This overrides anything that was found in ohci_quirks[]. */
381 static int param_quirks;
382 module_param_named(quirks, param_quirks, int, 0644);
383 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
384 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
385 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
386 	", AR/selfID endianness = "	__stringify(QUIRK_BE_HEADERS)
387 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
388 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
389 	", TI SLLZ059 erratum = "	__stringify(QUIRK_TI_SLLZ059)
390 	", IR wake unreliable = "	__stringify(QUIRK_IR_WAKE)
391 	")");
392 
393 #define OHCI_PARAM_DEBUG_AT_AR		1
394 #define OHCI_PARAM_DEBUG_SELFIDS	2
395 #define OHCI_PARAM_DEBUG_IRQS		4
396 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
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 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
405 	", or a combination, or all = -1)");
406 
407 static bool param_remote_dma;
408 module_param_named(remote_dma, param_remote_dma, bool, 0444);
409 MODULE_PARM_DESC(remote_dma, "Enable unfiltered remote DMA (default = N)");
410 
411 static void log_irqs(struct fw_ohci *ohci, u32 evt)
412 {
413 	if (likely(!(param_debug &
414 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
415 		return;
416 
417 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
418 	    !(evt & OHCI1394_busReset))
419 		return;
420 
421 	ohci_notice(ohci, "IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
422 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
423 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
424 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
425 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
426 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
427 	    evt & OHCI1394_isochRx		? " IR"			: "",
428 	    evt & OHCI1394_isochTx		? " IT"			: "",
429 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
430 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
431 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
432 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
433 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
434 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
435 	    evt & OHCI1394_busReset		? " busReset"		: "",
436 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
437 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
438 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
439 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
440 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
441 		    OHCI1394_cycleInconsistent |
442 		    OHCI1394_regAccessFail | OHCI1394_busReset)
443 						? " ?"			: "");
444 }
445 
446 static const char *speed[] = {
447 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
448 };
449 static const char *power[] = {
450 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
451 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
452 };
453 static const char port[] = { '.', '-', 'p', 'c', };
454 
455 static char _p(u32 *s, int shift)
456 {
457 	return port[*s >> shift & 3];
458 }
459 
460 static void log_selfids(struct fw_ohci *ohci, int generation, int self_id_count)
461 {
462 	u32 *s;
463 
464 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
465 		return;
466 
467 	ohci_notice(ohci, "%d selfIDs, generation %d, local node ID %04x\n",
468 		    self_id_count, generation, ohci->node_id);
469 
470 	for (s = ohci->self_id_buffer; self_id_count--; ++s)
471 		if ((*s & 1 << 23) == 0)
472 			ohci_notice(ohci,
473 			    "selfID 0: %08x, phy %d [%c%c%c] %s gc=%d %s %s%s%s\n",
474 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
475 			    speed[*s >> 14 & 3], *s >> 16 & 63,
476 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
477 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
478 		else
479 			ohci_notice(ohci,
480 			    "selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
481 			    *s, *s >> 24 & 63,
482 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
483 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
484 }
485 
486 static const char *evts[] = {
487 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
488 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
489 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
490 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
491 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
492 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
493 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
494 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
495 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
496 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
497 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
498 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
499 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
500 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
501 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
502 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
503 	[0x20] = "pending/cancelled",
504 };
505 static const char *tcodes[] = {
506 	[0x0] = "QW req",		[0x1] = "BW req",
507 	[0x2] = "W resp",		[0x3] = "-reserved-",
508 	[0x4] = "QR req",		[0x5] = "BR req",
509 	[0x6] = "QR resp",		[0x7] = "BR resp",
510 	[0x8] = "cycle start",		[0x9] = "Lk req",
511 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
512 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
513 	[0xe] = "link internal",	[0xf] = "-reserved-",
514 };
515 
516 static void log_ar_at_event(struct fw_ohci *ohci,
517 			    char dir, int speed, u32 *header, int evt)
518 {
519 	int tcode = header[0] >> 4 & 0xf;
520 	char specific[12];
521 
522 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
523 		return;
524 
525 	if (unlikely(evt >= ARRAY_SIZE(evts)))
526 			evt = 0x1f;
527 
528 	if (evt == OHCI1394_evt_bus_reset) {
529 		ohci_notice(ohci, "A%c evt_bus_reset, generation %d\n",
530 			    dir, (header[2] >> 16) & 0xff);
531 		return;
532 	}
533 
534 	switch (tcode) {
535 	case 0x0: case 0x6: case 0x8:
536 		snprintf(specific, sizeof(specific), " = %08x",
537 			 be32_to_cpu((__force __be32)header[3]));
538 		break;
539 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
540 		snprintf(specific, sizeof(specific), " %x,%x",
541 			 header[3] >> 16, header[3] & 0xffff);
542 		break;
543 	default:
544 		specific[0] = '\0';
545 	}
546 
547 	switch (tcode) {
548 	case 0xa:
549 		ohci_notice(ohci, "A%c %s, %s\n",
550 			    dir, evts[evt], tcodes[tcode]);
551 		break;
552 	case 0xe:
553 		ohci_notice(ohci, "A%c %s, PHY %08x %08x\n",
554 			    dir, evts[evt], header[1], header[2]);
555 		break;
556 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
557 		ohci_notice(ohci,
558 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s, %04x%08x%s\n",
559 			    dir, speed, header[0] >> 10 & 0x3f,
560 			    header[1] >> 16, header[0] >> 16, evts[evt],
561 			    tcodes[tcode], header[1] & 0xffff, header[2], specific);
562 		break;
563 	default:
564 		ohci_notice(ohci,
565 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s%s\n",
566 			    dir, speed, header[0] >> 10 & 0x3f,
567 			    header[1] >> 16, header[0] >> 16, evts[evt],
568 			    tcodes[tcode], specific);
569 	}
570 }
571 
572 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
573 {
574 	writel(data, ohci->registers + offset);
575 }
576 
577 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
578 {
579 	return readl(ohci->registers + offset);
580 }
581 
582 static inline void flush_writes(const struct fw_ohci *ohci)
583 {
584 	/* Do a dummy read to flush writes. */
585 	reg_read(ohci, OHCI1394_Version);
586 }
587 
588 /*
589  * Beware!  read_phy_reg(), write_phy_reg(), update_phy_reg(), and
590  * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
591  * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
592  * directly.  Exceptions are intrinsically serialized contexts like pci_probe.
593  */
594 static int read_phy_reg(struct fw_ohci *ohci, int addr)
595 {
596 	u32 val;
597 	int i;
598 
599 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
600 	for (i = 0; i < 3 + 100; i++) {
601 		val = reg_read(ohci, OHCI1394_PhyControl);
602 		if (!~val)
603 			return -ENODEV; /* Card was ejected. */
604 
605 		if (val & OHCI1394_PhyControl_ReadDone)
606 			return OHCI1394_PhyControl_ReadData(val);
607 
608 		/*
609 		 * Try a few times without waiting.  Sleeping is necessary
610 		 * only when the link/PHY interface is busy.
611 		 */
612 		if (i >= 3)
613 			msleep(1);
614 	}
615 	ohci_err(ohci, "failed to read phy reg %d\n", addr);
616 	dump_stack();
617 
618 	return -EBUSY;
619 }
620 
621 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
622 {
623 	int i;
624 
625 	reg_write(ohci, OHCI1394_PhyControl,
626 		  OHCI1394_PhyControl_Write(addr, val));
627 	for (i = 0; i < 3 + 100; i++) {
628 		val = reg_read(ohci, OHCI1394_PhyControl);
629 		if (!~val)
630 			return -ENODEV; /* Card was ejected. */
631 
632 		if (!(val & OHCI1394_PhyControl_WritePending))
633 			return 0;
634 
635 		if (i >= 3)
636 			msleep(1);
637 	}
638 	ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
639 	dump_stack();
640 
641 	return -EBUSY;
642 }
643 
644 static int update_phy_reg(struct fw_ohci *ohci, int addr,
645 			  int clear_bits, int set_bits)
646 {
647 	int ret = read_phy_reg(ohci, addr);
648 	if (ret < 0)
649 		return ret;
650 
651 	/*
652 	 * The interrupt status bits are cleared by writing a one bit.
653 	 * Avoid clearing them unless explicitly requested in set_bits.
654 	 */
655 	if (addr == 5)
656 		clear_bits |= PHY_INT_STATUS_BITS;
657 
658 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
659 }
660 
661 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
662 {
663 	int ret;
664 
665 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
666 	if (ret < 0)
667 		return ret;
668 
669 	return read_phy_reg(ohci, addr);
670 }
671 
672 static int ohci_read_phy_reg(struct fw_card *card, int addr)
673 {
674 	struct fw_ohci *ohci = fw_ohci(card);
675 	int ret;
676 
677 	mutex_lock(&ohci->phy_reg_mutex);
678 	ret = read_phy_reg(ohci, addr);
679 	mutex_unlock(&ohci->phy_reg_mutex);
680 
681 	return ret;
682 }
683 
684 static int ohci_update_phy_reg(struct fw_card *card, int addr,
685 			       int clear_bits, int set_bits)
686 {
687 	struct fw_ohci *ohci = fw_ohci(card);
688 	int ret;
689 
690 	mutex_lock(&ohci->phy_reg_mutex);
691 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
692 	mutex_unlock(&ohci->phy_reg_mutex);
693 
694 	return ret;
695 }
696 
697 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
698 {
699 	return page_private(ctx->pages[i]);
700 }
701 
702 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
703 {
704 	struct descriptor *d;
705 
706 	d = &ctx->descriptors[index];
707 	d->branch_address  &= cpu_to_le32(~0xf);
708 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
709 	d->transfer_status =  0;
710 
711 	wmb(); /* finish init of new descriptors before branch_address update */
712 	d = &ctx->descriptors[ctx->last_buffer_index];
713 	d->branch_address  |= cpu_to_le32(1);
714 
715 	ctx->last_buffer_index = index;
716 
717 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
718 }
719 
720 static void ar_context_release(struct ar_context *ctx)
721 {
722 	struct device *dev = ctx->ohci->card.device;
723 	unsigned int i;
724 
725 	if (!ctx->buffer)
726 		return;
727 
728 	vunmap(ctx->buffer);
729 
730 	for (i = 0; i < AR_BUFFERS; i++) {
731 		if (ctx->pages[i])
732 			dma_free_pages(dev, PAGE_SIZE, ctx->pages[i],
733 				       ar_buffer_bus(ctx, i), DMA_FROM_DEVICE);
734 	}
735 }
736 
737 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
738 {
739 	struct fw_ohci *ohci = ctx->ohci;
740 
741 	if (reg_read(ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
742 		reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
743 		flush_writes(ohci);
744 
745 		ohci_err(ohci, "AR error: %s; DMA stopped\n", error_msg);
746 	}
747 	/* FIXME: restart? */
748 }
749 
750 static inline unsigned int ar_next_buffer_index(unsigned int index)
751 {
752 	return (index + 1) % AR_BUFFERS;
753 }
754 
755 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
756 {
757 	return ar_next_buffer_index(ctx->last_buffer_index);
758 }
759 
760 /*
761  * We search for the buffer that contains the last AR packet DMA data written
762  * by the controller.
763  */
764 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
765 						 unsigned int *buffer_offset)
766 {
767 	unsigned int i, next_i, last = ctx->last_buffer_index;
768 	__le16 res_count, next_res_count;
769 
770 	i = ar_first_buffer_index(ctx);
771 	res_count = READ_ONCE(ctx->descriptors[i].res_count);
772 
773 	/* A buffer that is not yet completely filled must be the last one. */
774 	while (i != last && res_count == 0) {
775 
776 		/* Peek at the next descriptor. */
777 		next_i = ar_next_buffer_index(i);
778 		rmb(); /* read descriptors in order */
779 		next_res_count = READ_ONCE(ctx->descriptors[next_i].res_count);
780 		/*
781 		 * If the next descriptor is still empty, we must stop at this
782 		 * descriptor.
783 		 */
784 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
785 			/*
786 			 * The exception is when the DMA data for one packet is
787 			 * split over three buffers; in this case, the middle
788 			 * buffer's descriptor might be never updated by the
789 			 * controller and look still empty, and we have to peek
790 			 * at the third one.
791 			 */
792 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
793 				next_i = ar_next_buffer_index(next_i);
794 				rmb();
795 				next_res_count = READ_ONCE(ctx->descriptors[next_i].res_count);
796 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
797 					goto next_buffer_is_active;
798 			}
799 
800 			break;
801 		}
802 
803 next_buffer_is_active:
804 		i = next_i;
805 		res_count = next_res_count;
806 	}
807 
808 	rmb(); /* read res_count before the DMA data */
809 
810 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
811 	if (*buffer_offset > PAGE_SIZE) {
812 		*buffer_offset = 0;
813 		ar_context_abort(ctx, "corrupted descriptor");
814 	}
815 
816 	return i;
817 }
818 
819 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
820 				    unsigned int end_buffer_index,
821 				    unsigned int end_buffer_offset)
822 {
823 	unsigned int i;
824 
825 	i = ar_first_buffer_index(ctx);
826 	while (i != end_buffer_index) {
827 		dma_sync_single_for_cpu(ctx->ohci->card.device,
828 					ar_buffer_bus(ctx, i),
829 					PAGE_SIZE, DMA_FROM_DEVICE);
830 		i = ar_next_buffer_index(i);
831 	}
832 	if (end_buffer_offset > 0)
833 		dma_sync_single_for_cpu(ctx->ohci->card.device,
834 					ar_buffer_bus(ctx, i),
835 					end_buffer_offset, DMA_FROM_DEVICE);
836 }
837 
838 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
839 #define cond_le32_to_cpu(v) \
840 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
841 #else
842 #define cond_le32_to_cpu(v) le32_to_cpu(v)
843 #endif
844 
845 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
846 {
847 	struct fw_ohci *ohci = ctx->ohci;
848 	struct fw_packet p;
849 	u32 status, length, tcode;
850 	int evt;
851 
852 	p.header[0] = cond_le32_to_cpu(buffer[0]);
853 	p.header[1] = cond_le32_to_cpu(buffer[1]);
854 	p.header[2] = cond_le32_to_cpu(buffer[2]);
855 
856 	tcode = (p.header[0] >> 4) & 0x0f;
857 	switch (tcode) {
858 	case TCODE_WRITE_QUADLET_REQUEST:
859 	case TCODE_READ_QUADLET_RESPONSE:
860 		p.header[3] = (__force __u32) buffer[3];
861 		p.header_length = 16;
862 		p.payload_length = 0;
863 		break;
864 
865 	case TCODE_READ_BLOCK_REQUEST :
866 		p.header[3] = cond_le32_to_cpu(buffer[3]);
867 		p.header_length = 16;
868 		p.payload_length = 0;
869 		break;
870 
871 	case TCODE_WRITE_BLOCK_REQUEST:
872 	case TCODE_READ_BLOCK_RESPONSE:
873 	case TCODE_LOCK_REQUEST:
874 	case TCODE_LOCK_RESPONSE:
875 		p.header[3] = cond_le32_to_cpu(buffer[3]);
876 		p.header_length = 16;
877 		p.payload_length = p.header[3] >> 16;
878 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
879 			ar_context_abort(ctx, "invalid packet length");
880 			return NULL;
881 		}
882 		break;
883 
884 	case TCODE_WRITE_RESPONSE:
885 	case TCODE_READ_QUADLET_REQUEST:
886 	case OHCI_TCODE_PHY_PACKET:
887 		p.header_length = 12;
888 		p.payload_length = 0;
889 		break;
890 
891 	default:
892 		ar_context_abort(ctx, "invalid tcode");
893 		return NULL;
894 	}
895 
896 	p.payload = (void *) buffer + p.header_length;
897 
898 	/* FIXME: What to do about evt_* errors? */
899 	length = (p.header_length + p.payload_length + 3) / 4;
900 	status = cond_le32_to_cpu(buffer[length]);
901 	evt    = (status >> 16) & 0x1f;
902 
903 	p.ack        = evt - 16;
904 	p.speed      = (status >> 21) & 0x7;
905 	p.timestamp  = status & 0xffff;
906 	p.generation = ohci->request_generation;
907 
908 	log_ar_at_event(ohci, 'R', p.speed, p.header, evt);
909 
910 	/*
911 	 * Several controllers, notably from NEC and VIA, forget to
912 	 * write ack_complete status at PHY packet reception.
913 	 */
914 	if (evt == OHCI1394_evt_no_status &&
915 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
916 		p.ack = ACK_COMPLETE;
917 
918 	/*
919 	 * The OHCI bus reset handler synthesizes a PHY packet with
920 	 * the new generation number when a bus reset happens (see
921 	 * section 8.4.2.3).  This helps us determine when a request
922 	 * was received and make sure we send the response in the same
923 	 * generation.  We only need this for requests; for responses
924 	 * we use the unique tlabel for finding the matching
925 	 * request.
926 	 *
927 	 * Alas some chips sometimes emit bus reset packets with a
928 	 * wrong generation.  We set the correct generation for these
929 	 * at a slightly incorrect time (in bus_reset_work).
930 	 */
931 	if (evt == OHCI1394_evt_bus_reset) {
932 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
933 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
934 	} else if (ctx == &ohci->ar_request_ctx) {
935 		fw_core_handle_request(&ohci->card, &p);
936 	} else {
937 		fw_core_handle_response(&ohci->card, &p);
938 	}
939 
940 	return buffer + length + 1;
941 }
942 
943 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
944 {
945 	void *next;
946 
947 	while (p < end) {
948 		next = handle_ar_packet(ctx, p);
949 		if (!next)
950 			return p;
951 		p = next;
952 	}
953 
954 	return p;
955 }
956 
957 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
958 {
959 	unsigned int i;
960 
961 	i = ar_first_buffer_index(ctx);
962 	while (i != end_buffer) {
963 		dma_sync_single_for_device(ctx->ohci->card.device,
964 					   ar_buffer_bus(ctx, i),
965 					   PAGE_SIZE, DMA_FROM_DEVICE);
966 		ar_context_link_page(ctx, i);
967 		i = ar_next_buffer_index(i);
968 	}
969 }
970 
971 static void ar_context_tasklet(unsigned long data)
972 {
973 	struct ar_context *ctx = (struct ar_context *)data;
974 	unsigned int end_buffer_index, end_buffer_offset;
975 	void *p, *end;
976 
977 	p = ctx->pointer;
978 	if (!p)
979 		return;
980 
981 	end_buffer_index = ar_search_last_active_buffer(ctx,
982 							&end_buffer_offset);
983 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
984 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
985 
986 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
987 		/*
988 		 * The filled part of the overall buffer wraps around; handle
989 		 * all packets up to the buffer end here.  If the last packet
990 		 * wraps around, its tail will be visible after the buffer end
991 		 * because the buffer start pages are mapped there again.
992 		 */
993 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
994 		p = handle_ar_packets(ctx, p, buffer_end);
995 		if (p < buffer_end)
996 			goto error;
997 		/* adjust p to point back into the actual buffer */
998 		p -= AR_BUFFERS * PAGE_SIZE;
999 	}
1000 
1001 	p = handle_ar_packets(ctx, p, end);
1002 	if (p != end) {
1003 		if (p > end)
1004 			ar_context_abort(ctx, "inconsistent descriptor");
1005 		goto error;
1006 	}
1007 
1008 	ctx->pointer = p;
1009 	ar_recycle_buffers(ctx, end_buffer_index);
1010 
1011 	return;
1012 
1013 error:
1014 	ctx->pointer = NULL;
1015 }
1016 
1017 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
1018 			   unsigned int descriptors_offset, u32 regs)
1019 {
1020 	struct device *dev = ohci->card.device;
1021 	unsigned int i;
1022 	dma_addr_t dma_addr;
1023 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
1024 	struct descriptor *d;
1025 
1026 	ctx->regs        = regs;
1027 	ctx->ohci        = ohci;
1028 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
1029 
1030 	for (i = 0; i < AR_BUFFERS; i++) {
1031 		ctx->pages[i] = dma_alloc_pages(dev, PAGE_SIZE, &dma_addr,
1032 						DMA_FROM_DEVICE, GFP_KERNEL);
1033 		if (!ctx->pages[i])
1034 			goto out_of_memory;
1035 		set_page_private(ctx->pages[i], dma_addr);
1036 		dma_sync_single_for_device(dev, dma_addr, PAGE_SIZE,
1037 					   DMA_FROM_DEVICE);
1038 	}
1039 
1040 	for (i = 0; i < AR_BUFFERS; i++)
1041 		pages[i]              = ctx->pages[i];
1042 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
1043 		pages[AR_BUFFERS + i] = ctx->pages[i];
1044 	ctx->buffer = vmap(pages, ARRAY_SIZE(pages), VM_MAP, PAGE_KERNEL);
1045 	if (!ctx->buffer)
1046 		goto out_of_memory;
1047 
1048 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
1049 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
1050 
1051 	for (i = 0; i < AR_BUFFERS; i++) {
1052 		d = &ctx->descriptors[i];
1053 		d->req_count      = cpu_to_le16(PAGE_SIZE);
1054 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
1055 						DESCRIPTOR_STATUS |
1056 						DESCRIPTOR_BRANCH_ALWAYS);
1057 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
1058 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
1059 			ar_next_buffer_index(i) * sizeof(struct descriptor));
1060 	}
1061 
1062 	return 0;
1063 
1064 out_of_memory:
1065 	ar_context_release(ctx);
1066 
1067 	return -ENOMEM;
1068 }
1069 
1070 static void ar_context_run(struct ar_context *ctx)
1071 {
1072 	unsigned int i;
1073 
1074 	for (i = 0; i < AR_BUFFERS; i++)
1075 		ar_context_link_page(ctx, i);
1076 
1077 	ctx->pointer = ctx->buffer;
1078 
1079 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1080 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1081 }
1082 
1083 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1084 {
1085 	__le16 branch;
1086 
1087 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1088 
1089 	/* figure out which descriptor the branch address goes in */
1090 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1091 		return d;
1092 	else
1093 		return d + z - 1;
1094 }
1095 
1096 static void context_tasklet(unsigned long data)
1097 {
1098 	struct context *ctx = (struct context *) data;
1099 	struct descriptor *d, *last;
1100 	u32 address;
1101 	int z;
1102 	struct descriptor_buffer *desc;
1103 
1104 	desc = list_entry(ctx->buffer_list.next,
1105 			struct descriptor_buffer, list);
1106 	last = ctx->last;
1107 	while (last->branch_address != 0) {
1108 		struct descriptor_buffer *old_desc = desc;
1109 		address = le32_to_cpu(last->branch_address);
1110 		z = address & 0xf;
1111 		address &= ~0xf;
1112 		ctx->current_bus = address;
1113 
1114 		/* If the branch address points to a buffer outside of the
1115 		 * current buffer, advance to the next buffer. */
1116 		if (address < desc->buffer_bus ||
1117 				address >= desc->buffer_bus + desc->used)
1118 			desc = list_entry(desc->list.next,
1119 					struct descriptor_buffer, list);
1120 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1121 		last = find_branch_descriptor(d, z);
1122 
1123 		if (!ctx->callback(ctx, d, last))
1124 			break;
1125 
1126 		if (old_desc != desc) {
1127 			/* If we've advanced to the next buffer, move the
1128 			 * previous buffer to the free list. */
1129 			unsigned long flags;
1130 			old_desc->used = 0;
1131 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1132 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1133 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1134 		}
1135 		ctx->last = last;
1136 	}
1137 }
1138 
1139 /*
1140  * Allocate a new buffer and add it to the list of free buffers for this
1141  * context.  Must be called with ohci->lock held.
1142  */
1143 static int context_add_buffer(struct context *ctx)
1144 {
1145 	struct descriptor_buffer *desc;
1146 	dma_addr_t bus_addr;
1147 	int offset;
1148 
1149 	/*
1150 	 * 16MB of descriptors should be far more than enough for any DMA
1151 	 * program.  This will catch run-away userspace or DoS attacks.
1152 	 */
1153 	if (ctx->total_allocation >= 16*1024*1024)
1154 		return -ENOMEM;
1155 
1156 	desc = dmam_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE, &bus_addr, GFP_ATOMIC);
1157 	if (!desc)
1158 		return -ENOMEM;
1159 
1160 	offset = (void *)&desc->buffer - (void *)desc;
1161 	/*
1162 	 * Some controllers, like JMicron ones, always issue 0x20-byte DMA reads
1163 	 * for descriptors, even 0x10-byte ones. This can cause page faults when
1164 	 * an IOMMU is in use and the oversized read crosses a page boundary.
1165 	 * Work around this by always leaving at least 0x10 bytes of padding.
1166 	 */
1167 	desc->buffer_size = PAGE_SIZE - offset - 0x10;
1168 	desc->buffer_bus = bus_addr + offset;
1169 	desc->used = 0;
1170 
1171 	list_add_tail(&desc->list, &ctx->buffer_list);
1172 	ctx->total_allocation += PAGE_SIZE;
1173 
1174 	return 0;
1175 }
1176 
1177 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1178 			u32 regs, descriptor_callback_t callback)
1179 {
1180 	ctx->ohci = ohci;
1181 	ctx->regs = regs;
1182 	ctx->total_allocation = 0;
1183 
1184 	INIT_LIST_HEAD(&ctx->buffer_list);
1185 	if (context_add_buffer(ctx) < 0)
1186 		return -ENOMEM;
1187 
1188 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1189 			struct descriptor_buffer, list);
1190 
1191 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1192 	ctx->callback = callback;
1193 
1194 	/*
1195 	 * We put a dummy descriptor in the buffer that has a NULL
1196 	 * branch address and looks like it's been sent.  That way we
1197 	 * have a descriptor to append DMA programs to.
1198 	 */
1199 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1200 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1201 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1202 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1203 	ctx->last = ctx->buffer_tail->buffer;
1204 	ctx->prev = ctx->buffer_tail->buffer;
1205 	ctx->prev_z = 1;
1206 
1207 	return 0;
1208 }
1209 
1210 static void context_release(struct context *ctx)
1211 {
1212 	struct fw_card *card = &ctx->ohci->card;
1213 	struct descriptor_buffer *desc, *tmp;
1214 
1215 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list) {
1216 		dmam_free_coherent(card->device, PAGE_SIZE, desc,
1217 				   desc->buffer_bus - ((void *)&desc->buffer - (void *)desc));
1218 	}
1219 }
1220 
1221 /* Must be called with ohci->lock held */
1222 static struct descriptor *context_get_descriptors(struct context *ctx,
1223 						  int z, dma_addr_t *d_bus)
1224 {
1225 	struct descriptor *d = NULL;
1226 	struct descriptor_buffer *desc = ctx->buffer_tail;
1227 
1228 	if (z * sizeof(*d) > desc->buffer_size)
1229 		return NULL;
1230 
1231 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1232 		/* No room for the descriptor in this buffer, so advance to the
1233 		 * next one. */
1234 
1235 		if (desc->list.next == &ctx->buffer_list) {
1236 			/* If there is no free buffer next in the list,
1237 			 * allocate one. */
1238 			if (context_add_buffer(ctx) < 0)
1239 				return NULL;
1240 		}
1241 		desc = list_entry(desc->list.next,
1242 				struct descriptor_buffer, list);
1243 		ctx->buffer_tail = desc;
1244 	}
1245 
1246 	d = desc->buffer + desc->used / sizeof(*d);
1247 	memset(d, 0, z * sizeof(*d));
1248 	*d_bus = desc->buffer_bus + desc->used;
1249 
1250 	return d;
1251 }
1252 
1253 static void context_run(struct context *ctx, u32 extra)
1254 {
1255 	struct fw_ohci *ohci = ctx->ohci;
1256 
1257 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1258 		  le32_to_cpu(ctx->last->branch_address));
1259 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1260 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1261 	ctx->running = true;
1262 	flush_writes(ohci);
1263 }
1264 
1265 static void context_append(struct context *ctx,
1266 			   struct descriptor *d, int z, int extra)
1267 {
1268 	dma_addr_t d_bus;
1269 	struct descriptor_buffer *desc = ctx->buffer_tail;
1270 	struct descriptor *d_branch;
1271 
1272 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1273 
1274 	desc->used += (z + extra) * sizeof(*d);
1275 
1276 	wmb(); /* finish init of new descriptors before branch_address update */
1277 
1278 	d_branch = find_branch_descriptor(ctx->prev, ctx->prev_z);
1279 	d_branch->branch_address = cpu_to_le32(d_bus | z);
1280 
1281 	/*
1282 	 * VT6306 incorrectly checks only the single descriptor at the
1283 	 * CommandPtr when the wake bit is written, so if it's a
1284 	 * multi-descriptor block starting with an INPUT_MORE, put a copy of
1285 	 * the branch address in the first descriptor.
1286 	 *
1287 	 * Not doing this for transmit contexts since not sure how it interacts
1288 	 * with skip addresses.
1289 	 */
1290 	if (unlikely(ctx->ohci->quirks & QUIRK_IR_WAKE) &&
1291 	    d_branch != ctx->prev &&
1292 	    (ctx->prev->control & cpu_to_le16(DESCRIPTOR_CMD)) ==
1293 	     cpu_to_le16(DESCRIPTOR_INPUT_MORE)) {
1294 		ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1295 	}
1296 
1297 	ctx->prev = d;
1298 	ctx->prev_z = z;
1299 }
1300 
1301 static void context_stop(struct context *ctx)
1302 {
1303 	struct fw_ohci *ohci = ctx->ohci;
1304 	u32 reg;
1305 	int i;
1306 
1307 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1308 	ctx->running = false;
1309 
1310 	for (i = 0; i < 1000; i++) {
1311 		reg = reg_read(ohci, CONTROL_SET(ctx->regs));
1312 		if ((reg & CONTEXT_ACTIVE) == 0)
1313 			return;
1314 
1315 		if (i)
1316 			udelay(10);
1317 	}
1318 	ohci_err(ohci, "DMA context still active (0x%08x)\n", reg);
1319 }
1320 
1321 struct driver_data {
1322 	u8 inline_data[8];
1323 	struct fw_packet *packet;
1324 };
1325 
1326 /*
1327  * This function apppends a packet to the DMA queue for transmission.
1328  * Must always be called with the ochi->lock held to ensure proper
1329  * generation handling and locking around packet queue manipulation.
1330  */
1331 static int at_context_queue_packet(struct context *ctx,
1332 				   struct fw_packet *packet)
1333 {
1334 	struct fw_ohci *ohci = ctx->ohci;
1335 	dma_addr_t d_bus, payload_bus;
1336 	struct driver_data *driver_data;
1337 	struct descriptor *d, *last;
1338 	__le32 *header;
1339 	int z, tcode;
1340 
1341 	d = context_get_descriptors(ctx, 4, &d_bus);
1342 	if (d == NULL) {
1343 		packet->ack = RCODE_SEND_ERROR;
1344 		return -1;
1345 	}
1346 
1347 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1348 	d[0].res_count = cpu_to_le16(packet->timestamp);
1349 
1350 	/*
1351 	 * The DMA format for asynchronous link packets is different
1352 	 * from the IEEE1394 layout, so shift the fields around
1353 	 * accordingly.
1354 	 */
1355 
1356 	tcode = (packet->header[0] >> 4) & 0x0f;
1357 	header = (__le32 *) &d[1];
1358 	switch (tcode) {
1359 	case TCODE_WRITE_QUADLET_REQUEST:
1360 	case TCODE_WRITE_BLOCK_REQUEST:
1361 	case TCODE_WRITE_RESPONSE:
1362 	case TCODE_READ_QUADLET_REQUEST:
1363 	case TCODE_READ_BLOCK_REQUEST:
1364 	case TCODE_READ_QUADLET_RESPONSE:
1365 	case TCODE_READ_BLOCK_RESPONSE:
1366 	case TCODE_LOCK_REQUEST:
1367 	case TCODE_LOCK_RESPONSE:
1368 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1369 					(packet->speed << 16));
1370 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1371 					(packet->header[0] & 0xffff0000));
1372 		header[2] = cpu_to_le32(packet->header[2]);
1373 
1374 		if (TCODE_IS_BLOCK_PACKET(tcode))
1375 			header[3] = cpu_to_le32(packet->header[3]);
1376 		else
1377 			header[3] = (__force __le32) packet->header[3];
1378 
1379 		d[0].req_count = cpu_to_le16(packet->header_length);
1380 		break;
1381 
1382 	case TCODE_LINK_INTERNAL:
1383 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1384 					(packet->speed << 16));
1385 		header[1] = cpu_to_le32(packet->header[1]);
1386 		header[2] = cpu_to_le32(packet->header[2]);
1387 		d[0].req_count = cpu_to_le16(12);
1388 
1389 		if (is_ping_packet(&packet->header[1]))
1390 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1391 		break;
1392 
1393 	case TCODE_STREAM_DATA:
1394 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1395 					(packet->speed << 16));
1396 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1397 		d[0].req_count = cpu_to_le16(8);
1398 		break;
1399 
1400 	default:
1401 		/* BUG(); */
1402 		packet->ack = RCODE_SEND_ERROR;
1403 		return -1;
1404 	}
1405 
1406 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1407 	driver_data = (struct driver_data *) &d[3];
1408 	driver_data->packet = packet;
1409 	packet->driver_data = driver_data;
1410 
1411 	if (packet->payload_length > 0) {
1412 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1413 			payload_bus = dma_map_single(ohci->card.device,
1414 						     packet->payload,
1415 						     packet->payload_length,
1416 						     DMA_TO_DEVICE);
1417 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1418 				packet->ack = RCODE_SEND_ERROR;
1419 				return -1;
1420 			}
1421 			packet->payload_bus	= payload_bus;
1422 			packet->payload_mapped	= true;
1423 		} else {
1424 			memcpy(driver_data->inline_data, packet->payload,
1425 			       packet->payload_length);
1426 			payload_bus = d_bus + 3 * sizeof(*d);
1427 		}
1428 
1429 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1430 		d[2].data_address = cpu_to_le32(payload_bus);
1431 		last = &d[2];
1432 		z = 3;
1433 	} else {
1434 		last = &d[0];
1435 		z = 2;
1436 	}
1437 
1438 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1439 				     DESCRIPTOR_IRQ_ALWAYS |
1440 				     DESCRIPTOR_BRANCH_ALWAYS);
1441 
1442 	/* FIXME: Document how the locking works. */
1443 	if (ohci->generation != packet->generation) {
1444 		if (packet->payload_mapped)
1445 			dma_unmap_single(ohci->card.device, payload_bus,
1446 					 packet->payload_length, DMA_TO_DEVICE);
1447 		packet->ack = RCODE_GENERATION;
1448 		return -1;
1449 	}
1450 
1451 	context_append(ctx, d, z, 4 - z);
1452 
1453 	if (ctx->running)
1454 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1455 	else
1456 		context_run(ctx, 0);
1457 
1458 	return 0;
1459 }
1460 
1461 static void at_context_flush(struct context *ctx)
1462 {
1463 	tasklet_disable(&ctx->tasklet);
1464 
1465 	ctx->flushing = true;
1466 	context_tasklet((unsigned long)ctx);
1467 	ctx->flushing = false;
1468 
1469 	tasklet_enable(&ctx->tasklet);
1470 }
1471 
1472 static int handle_at_packet(struct context *context,
1473 			    struct descriptor *d,
1474 			    struct descriptor *last)
1475 {
1476 	struct driver_data *driver_data;
1477 	struct fw_packet *packet;
1478 	struct fw_ohci *ohci = context->ohci;
1479 	int evt;
1480 
1481 	if (last->transfer_status == 0 && !context->flushing)
1482 		/* This descriptor isn't done yet, stop iteration. */
1483 		return 0;
1484 
1485 	driver_data = (struct driver_data *) &d[3];
1486 	packet = driver_data->packet;
1487 	if (packet == NULL)
1488 		/* This packet was cancelled, just continue. */
1489 		return 1;
1490 
1491 	if (packet->payload_mapped)
1492 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1493 				 packet->payload_length, DMA_TO_DEVICE);
1494 
1495 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1496 	packet->timestamp = le16_to_cpu(last->res_count);
1497 
1498 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, evt);
1499 
1500 	switch (evt) {
1501 	case OHCI1394_evt_timeout:
1502 		/* Async response transmit timed out. */
1503 		packet->ack = RCODE_CANCELLED;
1504 		break;
1505 
1506 	case OHCI1394_evt_flushed:
1507 		/*
1508 		 * The packet was flushed should give same error as
1509 		 * when we try to use a stale generation count.
1510 		 */
1511 		packet->ack = RCODE_GENERATION;
1512 		break;
1513 
1514 	case OHCI1394_evt_missing_ack:
1515 		if (context->flushing)
1516 			packet->ack = RCODE_GENERATION;
1517 		else {
1518 			/*
1519 			 * Using a valid (current) generation count, but the
1520 			 * node is not on the bus or not sending acks.
1521 			 */
1522 			packet->ack = RCODE_NO_ACK;
1523 		}
1524 		break;
1525 
1526 	case ACK_COMPLETE + 0x10:
1527 	case ACK_PENDING + 0x10:
1528 	case ACK_BUSY_X + 0x10:
1529 	case ACK_BUSY_A + 0x10:
1530 	case ACK_BUSY_B + 0x10:
1531 	case ACK_DATA_ERROR + 0x10:
1532 	case ACK_TYPE_ERROR + 0x10:
1533 		packet->ack = evt - 0x10;
1534 		break;
1535 
1536 	case OHCI1394_evt_no_status:
1537 		if (context->flushing) {
1538 			packet->ack = RCODE_GENERATION;
1539 			break;
1540 		}
1541 		fallthrough;
1542 
1543 	default:
1544 		packet->ack = RCODE_SEND_ERROR;
1545 		break;
1546 	}
1547 
1548 	packet->callback(packet, &ohci->card, packet->ack);
1549 
1550 	return 1;
1551 }
1552 
1553 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1554 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1555 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1556 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1557 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
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 = HEADER_GET_TCODE(packet->header[0]);
1566 	if (TCODE_IS_BLOCK_PACKET(tcode))
1567 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
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 	fw_core_handle_response(&ohci->card, &response);
1584 }
1585 
1586 static void handle_local_lock(struct fw_ohci *ohci,
1587 			      struct fw_packet *packet, u32 csr)
1588 {
1589 	struct fw_packet response;
1590 	int tcode, length, ext_tcode, sel, try;
1591 	__be32 *payload, lock_old;
1592 	u32 lock_arg, lock_data;
1593 
1594 	tcode = HEADER_GET_TCODE(packet->header[0]);
1595 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1596 	payload = packet->payload;
1597 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1598 
1599 	if (tcode == TCODE_LOCK_REQUEST &&
1600 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1601 		lock_arg = be32_to_cpu(payload[0]);
1602 		lock_data = be32_to_cpu(payload[1]);
1603 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1604 		lock_arg = 0;
1605 		lock_data = 0;
1606 	} else {
1607 		fw_fill_response(&response, packet->header,
1608 				 RCODE_TYPE_ERROR, NULL, 0);
1609 		goto out;
1610 	}
1611 
1612 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1613 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1614 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1615 	reg_write(ohci, OHCI1394_CSRControl, sel);
1616 
1617 	for (try = 0; try < 20; try++)
1618 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1619 			lock_old = cpu_to_be32(reg_read(ohci,
1620 							OHCI1394_CSRData));
1621 			fw_fill_response(&response, packet->header,
1622 					 RCODE_COMPLETE,
1623 					 &lock_old, sizeof(lock_old));
1624 			goto out;
1625 		}
1626 
1627 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
1628 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1629 
1630  out:
1631 	fw_core_handle_response(&ohci->card, &response);
1632 }
1633 
1634 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1635 {
1636 	u64 offset, csr;
1637 
1638 	if (ctx == &ctx->ohci->at_request_ctx) {
1639 		packet->ack = ACK_PENDING;
1640 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1641 	}
1642 
1643 	offset =
1644 		((unsigned long long)
1645 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1646 		packet->header[2];
1647 	csr = offset - CSR_REGISTER_BASE;
1648 
1649 	/* Handle config rom reads. */
1650 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1651 		handle_local_rom(ctx->ohci, packet, csr);
1652 	else switch (csr) {
1653 	case CSR_BUS_MANAGER_ID:
1654 	case CSR_BANDWIDTH_AVAILABLE:
1655 	case CSR_CHANNELS_AVAILABLE_HI:
1656 	case CSR_CHANNELS_AVAILABLE_LO:
1657 		handle_local_lock(ctx->ohci, packet, csr);
1658 		break;
1659 	default:
1660 		if (ctx == &ctx->ohci->at_request_ctx)
1661 			fw_core_handle_request(&ctx->ohci->card, packet);
1662 		else
1663 			fw_core_handle_response(&ctx->ohci->card, packet);
1664 		break;
1665 	}
1666 
1667 	if (ctx == &ctx->ohci->at_response_ctx) {
1668 		packet->ack = ACK_COMPLETE;
1669 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1670 	}
1671 }
1672 
1673 static u32 get_cycle_time(struct fw_ohci *ohci);
1674 
1675 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1676 {
1677 	unsigned long flags;
1678 	int ret;
1679 
1680 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1681 
1682 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1683 	    ctx->ohci->generation == packet->generation) {
1684 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1685 
1686 		// Timestamping on behalf of the hardware.
1687 		packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ctx->ohci));
1688 
1689 		handle_local_request(ctx, packet);
1690 		return;
1691 	}
1692 
1693 	ret = at_context_queue_packet(ctx, packet);
1694 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1695 
1696 	if (ret < 0) {
1697 		// Timestamping on behalf of the hardware.
1698 		packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ctx->ohci));
1699 
1700 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1701 	}
1702 }
1703 
1704 static void detect_dead_context(struct fw_ohci *ohci,
1705 				const char *name, unsigned int regs)
1706 {
1707 	u32 ctl;
1708 
1709 	ctl = reg_read(ohci, CONTROL_SET(regs));
1710 	if (ctl & CONTEXT_DEAD)
1711 		ohci_err(ohci, "DMA context %s has stopped, error code: %s\n",
1712 			name, evts[ctl & 0x1f]);
1713 }
1714 
1715 static void handle_dead_contexts(struct fw_ohci *ohci)
1716 {
1717 	unsigned int i;
1718 	char name[8];
1719 
1720 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1721 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1722 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1723 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1724 	for (i = 0; i < 32; ++i) {
1725 		if (!(ohci->it_context_support & (1 << i)))
1726 			continue;
1727 		sprintf(name, "IT%u", i);
1728 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1729 	}
1730 	for (i = 0; i < 32; ++i) {
1731 		if (!(ohci->ir_context_support & (1 << i)))
1732 			continue;
1733 		sprintf(name, "IR%u", i);
1734 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1735 	}
1736 	/* TODO: maybe try to flush and restart the dead contexts */
1737 }
1738 
1739 static u32 cycle_timer_ticks(u32 cycle_timer)
1740 {
1741 	u32 ticks;
1742 
1743 	ticks = cycle_timer & 0xfff;
1744 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1745 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1746 
1747 	return ticks;
1748 }
1749 
1750 /*
1751  * Some controllers exhibit one or more of the following bugs when updating the
1752  * iso cycle timer register:
1753  *  - When the lowest six bits are wrapping around to zero, a read that happens
1754  *    at the same time will return garbage in the lowest ten bits.
1755  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1756  *    not incremented for about 60 ns.
1757  *  - Occasionally, the entire register reads zero.
1758  *
1759  * To catch these, we read the register three times and ensure that the
1760  * difference between each two consecutive reads is approximately the same, i.e.
1761  * less than twice the other.  Furthermore, any negative difference indicates an
1762  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1763  * execute, so we have enough precision to compute the ratio of the differences.)
1764  */
1765 static u32 get_cycle_time(struct fw_ohci *ohci)
1766 {
1767 	u32 c0, c1, c2;
1768 	u32 t0, t1, t2;
1769 	s32 diff01, diff12;
1770 	int i;
1771 
1772 	if (has_reboot_by_cycle_timer_read_quirk(ohci))
1773 		return 0;
1774 
1775 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1776 
1777 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1778 		i = 0;
1779 		c1 = c2;
1780 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1781 		do {
1782 			c0 = c1;
1783 			c1 = c2;
1784 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1785 			t0 = cycle_timer_ticks(c0);
1786 			t1 = cycle_timer_ticks(c1);
1787 			t2 = cycle_timer_ticks(c2);
1788 			diff01 = t1 - t0;
1789 			diff12 = t2 - t1;
1790 		} while ((diff01 <= 0 || diff12 <= 0 ||
1791 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1792 			 && i++ < 20);
1793 	}
1794 
1795 	return c2;
1796 }
1797 
1798 /*
1799  * This function has to be called at least every 64 seconds.  The bus_time
1800  * field stores not only the upper 25 bits of the BUS_TIME register but also
1801  * the most significant bit of the cycle timer in bit 6 so that we can detect
1802  * changes in this bit.
1803  */
1804 static u32 update_bus_time(struct fw_ohci *ohci)
1805 {
1806 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1807 
1808 	if (unlikely(!ohci->bus_time_running)) {
1809 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds);
1810 		ohci->bus_time = (lower_32_bits(ktime_get_seconds()) & ~0x7f) |
1811 		                 (cycle_time_seconds & 0x40);
1812 		ohci->bus_time_running = true;
1813 	}
1814 
1815 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1816 		ohci->bus_time += 0x40;
1817 
1818 	return ohci->bus_time | cycle_time_seconds;
1819 }
1820 
1821 static int get_status_for_port(struct fw_ohci *ohci, int port_index)
1822 {
1823 	int reg;
1824 
1825 	mutex_lock(&ohci->phy_reg_mutex);
1826 	reg = write_phy_reg(ohci, 7, port_index);
1827 	if (reg >= 0)
1828 		reg = read_phy_reg(ohci, 8);
1829 	mutex_unlock(&ohci->phy_reg_mutex);
1830 	if (reg < 0)
1831 		return reg;
1832 
1833 	switch (reg & 0x0f) {
1834 	case 0x06:
1835 		return 2;	/* is child node (connected to parent node) */
1836 	case 0x0e:
1837 		return 3;	/* is parent node (connected to child node) */
1838 	}
1839 	return 1;		/* not connected */
1840 }
1841 
1842 static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
1843 	int self_id_count)
1844 {
1845 	int i;
1846 	u32 entry;
1847 
1848 	for (i = 0; i < self_id_count; i++) {
1849 		entry = ohci->self_id_buffer[i];
1850 		if ((self_id & 0xff000000) == (entry & 0xff000000))
1851 			return -1;
1852 		if ((self_id & 0xff000000) < (entry & 0xff000000))
1853 			return i;
1854 	}
1855 	return i;
1856 }
1857 
1858 static int initiated_reset(struct fw_ohci *ohci)
1859 {
1860 	int reg;
1861 	int ret = 0;
1862 
1863 	mutex_lock(&ohci->phy_reg_mutex);
1864 	reg = write_phy_reg(ohci, 7, 0xe0); /* Select page 7 */
1865 	if (reg >= 0) {
1866 		reg = read_phy_reg(ohci, 8);
1867 		reg |= 0x40;
1868 		reg = write_phy_reg(ohci, 8, reg); /* set PMODE bit */
1869 		if (reg >= 0) {
1870 			reg = read_phy_reg(ohci, 12); /* read register 12 */
1871 			if (reg >= 0) {
1872 				if ((reg & 0x08) == 0x08) {
1873 					/* bit 3 indicates "initiated reset" */
1874 					ret = 0x2;
1875 				}
1876 			}
1877 		}
1878 	}
1879 	mutex_unlock(&ohci->phy_reg_mutex);
1880 	return ret;
1881 }
1882 
1883 /*
1884  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
1885  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
1886  * Construct the selfID from phy register contents.
1887  */
1888 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
1889 {
1890 	int reg, i, pos, status;
1891 	/* link active 1, speed 3, bridge 0, contender 1, more packets 0 */
1892 	u32 self_id = 0x8040c800;
1893 
1894 	reg = reg_read(ohci, OHCI1394_NodeID);
1895 	if (!(reg & OHCI1394_NodeID_idValid)) {
1896 		ohci_notice(ohci,
1897 			    "node ID not valid, new bus reset in progress\n");
1898 		return -EBUSY;
1899 	}
1900 	self_id |= ((reg & 0x3f) << 24); /* phy ID */
1901 
1902 	reg = ohci_read_phy_reg(&ohci->card, 4);
1903 	if (reg < 0)
1904 		return reg;
1905 	self_id |= ((reg & 0x07) << 8); /* power class */
1906 
1907 	reg = ohci_read_phy_reg(&ohci->card, 1);
1908 	if (reg < 0)
1909 		return reg;
1910 	self_id |= ((reg & 0x3f) << 16); /* gap count */
1911 
1912 	for (i = 0; i < 3; i++) {
1913 		status = get_status_for_port(ohci, i);
1914 		if (status < 0)
1915 			return status;
1916 		self_id |= ((status & 0x3) << (6 - (i * 2)));
1917 	}
1918 
1919 	self_id |= initiated_reset(ohci);
1920 
1921 	pos = get_self_id_pos(ohci, self_id, self_id_count);
1922 	if (pos >= 0) {
1923 		memmove(&(ohci->self_id_buffer[pos+1]),
1924 			&(ohci->self_id_buffer[pos]),
1925 			(self_id_count - pos) * sizeof(*ohci->self_id_buffer));
1926 		ohci->self_id_buffer[pos] = self_id;
1927 		self_id_count++;
1928 	}
1929 	return self_id_count;
1930 }
1931 
1932 static void bus_reset_work(struct work_struct *work)
1933 {
1934 	struct fw_ohci *ohci =
1935 		container_of(work, struct fw_ohci, bus_reset_work);
1936 	int self_id_count, generation, new_generation, i, j;
1937 	u32 reg;
1938 	void *free_rom = NULL;
1939 	dma_addr_t free_rom_bus = 0;
1940 	bool is_new_root;
1941 
1942 	reg = reg_read(ohci, OHCI1394_NodeID);
1943 	if (!(reg & OHCI1394_NodeID_idValid)) {
1944 		ohci_notice(ohci,
1945 			    "node ID not valid, new bus reset in progress\n");
1946 		return;
1947 	}
1948 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1949 		ohci_notice(ohci, "malconfigured bus\n");
1950 		return;
1951 	}
1952 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1953 			       OHCI1394_NodeID_nodeNumber);
1954 
1955 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1956 	if (!(ohci->is_root && is_new_root))
1957 		reg_write(ohci, OHCI1394_LinkControlSet,
1958 			  OHCI1394_LinkControl_cycleMaster);
1959 	ohci->is_root = is_new_root;
1960 
1961 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1962 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1963 		ohci_notice(ohci, "self ID receive error\n");
1964 		return;
1965 	}
1966 	/*
1967 	 * The count in the SelfIDCount register is the number of
1968 	 * bytes in the self ID receive buffer.  Since we also receive
1969 	 * the inverted quadlets and a header quadlet, we shift one
1970 	 * bit extra to get the actual number of self IDs.
1971 	 */
1972 	self_id_count = (reg >> 3) & 0xff;
1973 
1974 	if (self_id_count > 252) {
1975 		ohci_notice(ohci, "bad selfIDSize (%08x)\n", reg);
1976 		return;
1977 	}
1978 
1979 	generation = (cond_le32_to_cpu(ohci->self_id[0]) >> 16) & 0xff;
1980 	rmb();
1981 
1982 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1983 		u32 id  = cond_le32_to_cpu(ohci->self_id[i]);
1984 		u32 id2 = cond_le32_to_cpu(ohci->self_id[i + 1]);
1985 
1986 		if (id != ~id2) {
1987 			/*
1988 			 * If the invalid data looks like a cycle start packet,
1989 			 * it's likely to be the result of the cycle master
1990 			 * having a wrong gap count.  In this case, the self IDs
1991 			 * so far are valid and should be processed so that the
1992 			 * bus manager can then correct the gap count.
1993 			 */
1994 			if (id == 0xffff008f) {
1995 				ohci_notice(ohci, "ignoring spurious self IDs\n");
1996 				self_id_count = j;
1997 				break;
1998 			}
1999 
2000 			ohci_notice(ohci, "bad self ID %d/%d (%08x != ~%08x)\n",
2001 				    j, self_id_count, id, id2);
2002 			return;
2003 		}
2004 		ohci->self_id_buffer[j] = id;
2005 	}
2006 
2007 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2008 		self_id_count = find_and_insert_self_id(ohci, self_id_count);
2009 		if (self_id_count < 0) {
2010 			ohci_notice(ohci,
2011 				    "could not construct local self ID\n");
2012 			return;
2013 		}
2014 	}
2015 
2016 	if (self_id_count == 0) {
2017 		ohci_notice(ohci, "no self IDs\n");
2018 		return;
2019 	}
2020 	rmb();
2021 
2022 	/*
2023 	 * Check the consistency of the self IDs we just read.  The
2024 	 * problem we face is that a new bus reset can start while we
2025 	 * read out the self IDs from the DMA buffer. If this happens,
2026 	 * the DMA buffer will be overwritten with new self IDs and we
2027 	 * will read out inconsistent data.  The OHCI specification
2028 	 * (section 11.2) recommends a technique similar to
2029 	 * linux/seqlock.h, where we remember the generation of the
2030 	 * self IDs in the buffer before reading them out and compare
2031 	 * it to the current generation after reading them out.  If
2032 	 * the two generations match we know we have a consistent set
2033 	 * of self IDs.
2034 	 */
2035 
2036 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
2037 	if (new_generation != generation) {
2038 		ohci_notice(ohci, "new bus reset, discarding self ids\n");
2039 		return;
2040 	}
2041 
2042 	/* FIXME: Document how the locking works. */
2043 	spin_lock_irq(&ohci->lock);
2044 
2045 	ohci->generation = -1; /* prevent AT packet queueing */
2046 	context_stop(&ohci->at_request_ctx);
2047 	context_stop(&ohci->at_response_ctx);
2048 
2049 	spin_unlock_irq(&ohci->lock);
2050 
2051 	/*
2052 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
2053 	 * packets in the AT queues and software needs to drain them.
2054 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
2055 	 */
2056 	at_context_flush(&ohci->at_request_ctx);
2057 	at_context_flush(&ohci->at_response_ctx);
2058 
2059 	spin_lock_irq(&ohci->lock);
2060 
2061 	ohci->generation = generation;
2062 	reg_write(ohci, OHCI1394_IntEventClear, 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 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 
2135 	if (event & OHCI1394_selfIDComplete)
2136 		queue_work(selfid_workqueue, &ohci->bus_reset_work);
2137 
2138 	if (event & OHCI1394_RQPkt)
2139 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
2140 
2141 	if (event & OHCI1394_RSPkt)
2142 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
2143 
2144 	if (event & OHCI1394_reqTxComplete)
2145 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
2146 
2147 	if (event & OHCI1394_respTxComplete)
2148 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
2149 
2150 	if (event & OHCI1394_isochRx) {
2151 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
2152 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
2153 
2154 		while (iso_event) {
2155 			i = ffs(iso_event) - 1;
2156 			tasklet_schedule(
2157 				&ohci->ir_context_list[i].context.tasklet);
2158 			iso_event &= ~(1 << i);
2159 		}
2160 	}
2161 
2162 	if (event & OHCI1394_isochTx) {
2163 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
2164 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
2165 
2166 		while (iso_event) {
2167 			i = ffs(iso_event) - 1;
2168 			tasklet_schedule(
2169 				&ohci->it_context_list[i].context.tasklet);
2170 			iso_event &= ~(1 << i);
2171 		}
2172 	}
2173 
2174 	if (unlikely(event & OHCI1394_regAccessFail))
2175 		ohci_err(ohci, "register access failure\n");
2176 
2177 	if (unlikely(event & OHCI1394_postedWriteErr)) {
2178 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
2179 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
2180 		reg_write(ohci, OHCI1394_IntEventClear,
2181 			  OHCI1394_postedWriteErr);
2182 		if (printk_ratelimit())
2183 			ohci_err(ohci, "PCI posted write error\n");
2184 	}
2185 
2186 	if (unlikely(event & OHCI1394_cycleTooLong)) {
2187 		if (printk_ratelimit())
2188 			ohci_notice(ohci, "isochronous cycle too long\n");
2189 		reg_write(ohci, OHCI1394_LinkControlSet,
2190 			  OHCI1394_LinkControl_cycleMaster);
2191 	}
2192 
2193 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
2194 		/*
2195 		 * We need to clear this event bit in order to make
2196 		 * cycleMatch isochronous I/O work.  In theory we should
2197 		 * stop active cycleMatch iso contexts now and restart
2198 		 * them at least two cycles later.  (FIXME?)
2199 		 */
2200 		if (printk_ratelimit())
2201 			ohci_notice(ohci, "isochronous cycle inconsistent\n");
2202 	}
2203 
2204 	if (unlikely(event & OHCI1394_unrecoverableError))
2205 		handle_dead_contexts(ohci);
2206 
2207 	if (event & OHCI1394_cycle64Seconds) {
2208 		spin_lock(&ohci->lock);
2209 		update_bus_time(ohci);
2210 		spin_unlock(&ohci->lock);
2211 	} else
2212 		flush_writes(ohci);
2213 
2214 	return IRQ_HANDLED;
2215 }
2216 
2217 static int software_reset(struct fw_ohci *ohci)
2218 {
2219 	u32 val;
2220 	int i;
2221 
2222 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
2223 	for (i = 0; i < 500; i++) {
2224 		val = reg_read(ohci, OHCI1394_HCControlSet);
2225 		if (!~val)
2226 			return -ENODEV; /* Card was ejected. */
2227 
2228 		if (!(val & OHCI1394_HCControl_softReset))
2229 			return 0;
2230 
2231 		msleep(1);
2232 	}
2233 
2234 	return -EBUSY;
2235 }
2236 
2237 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
2238 {
2239 	size_t size = length * 4;
2240 
2241 	memcpy(dest, src, size);
2242 	if (size < CONFIG_ROM_SIZE)
2243 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
2244 }
2245 
2246 static int configure_1394a_enhancements(struct fw_ohci *ohci)
2247 {
2248 	bool enable_1394a;
2249 	int ret, clear, set, offset;
2250 
2251 	/* Check if the driver should configure link and PHY. */
2252 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
2253 	      OHCI1394_HCControl_programPhyEnable))
2254 		return 0;
2255 
2256 	/* Paranoia: check whether the PHY supports 1394a, too. */
2257 	enable_1394a = false;
2258 	ret = read_phy_reg(ohci, 2);
2259 	if (ret < 0)
2260 		return ret;
2261 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2262 		ret = read_paged_phy_reg(ohci, 1, 8);
2263 		if (ret < 0)
2264 			return ret;
2265 		if (ret >= 1)
2266 			enable_1394a = true;
2267 	}
2268 
2269 	if (ohci->quirks & QUIRK_NO_1394A)
2270 		enable_1394a = false;
2271 
2272 	/* Configure PHY and link consistently. */
2273 	if (enable_1394a) {
2274 		clear = 0;
2275 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2276 	} else {
2277 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2278 		set = 0;
2279 	}
2280 	ret = update_phy_reg(ohci, 5, clear, set);
2281 	if (ret < 0)
2282 		return ret;
2283 
2284 	if (enable_1394a)
2285 		offset = OHCI1394_HCControlSet;
2286 	else
2287 		offset = OHCI1394_HCControlClear;
2288 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2289 
2290 	/* Clean up: configuration has been taken care of. */
2291 	reg_write(ohci, OHCI1394_HCControlClear,
2292 		  OHCI1394_HCControl_programPhyEnable);
2293 
2294 	return 0;
2295 }
2296 
2297 static int probe_tsb41ba3d(struct fw_ohci *ohci)
2298 {
2299 	/* TI vendor ID = 0x080028, TSB41BA3D product ID = 0x833005 (sic) */
2300 	static const u8 id[] = { 0x08, 0x00, 0x28, 0x83, 0x30, 0x05, };
2301 	int reg, i;
2302 
2303 	reg = read_phy_reg(ohci, 2);
2304 	if (reg < 0)
2305 		return reg;
2306 	if ((reg & PHY_EXTENDED_REGISTERS) != PHY_EXTENDED_REGISTERS)
2307 		return 0;
2308 
2309 	for (i = ARRAY_SIZE(id) - 1; i >= 0; i--) {
2310 		reg = read_paged_phy_reg(ohci, 1, i + 10);
2311 		if (reg < 0)
2312 			return reg;
2313 		if (reg != id[i])
2314 			return 0;
2315 	}
2316 	return 1;
2317 }
2318 
2319 static int ohci_enable(struct fw_card *card,
2320 		       const __be32 *config_rom, size_t length)
2321 {
2322 	struct fw_ohci *ohci = fw_ohci(card);
2323 	u32 lps, version, irqs;
2324 	int i, ret;
2325 
2326 	ret = software_reset(ohci);
2327 	if (ret < 0) {
2328 		ohci_err(ohci, "failed to reset ohci card\n");
2329 		return ret;
2330 	}
2331 
2332 	/*
2333 	 * Now enable LPS, which we need in order to start accessing
2334 	 * most of the registers.  In fact, on some cards (ALI M5251),
2335 	 * accessing registers in the SClk domain without LPS enabled
2336 	 * will lock up the machine.  Wait 50msec to make sure we have
2337 	 * full link enabled.  However, with some cards (well, at least
2338 	 * a JMicron PCIe card), we have to try again sometimes.
2339 	 *
2340 	 * TI TSB82AA2 + TSB81BA3(A) cards signal LPS enabled early but
2341 	 * cannot actually use the phy at that time.  These need tens of
2342 	 * millisecods pause between LPS write and first phy access too.
2343 	 */
2344 
2345 	reg_write(ohci, OHCI1394_HCControlSet,
2346 		  OHCI1394_HCControl_LPS |
2347 		  OHCI1394_HCControl_postedWriteEnable);
2348 	flush_writes(ohci);
2349 
2350 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2351 		msleep(50);
2352 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2353 		      OHCI1394_HCControl_LPS;
2354 	}
2355 
2356 	if (!lps) {
2357 		ohci_err(ohci, "failed to set Link Power Status\n");
2358 		return -EIO;
2359 	}
2360 
2361 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2362 		ret = probe_tsb41ba3d(ohci);
2363 		if (ret < 0)
2364 			return ret;
2365 		if (ret)
2366 			ohci_notice(ohci, "local TSB41BA3D phy\n");
2367 		else
2368 			ohci->quirks &= ~QUIRK_TI_SLLZ059;
2369 	}
2370 
2371 	reg_write(ohci, OHCI1394_HCControlClear,
2372 		  OHCI1394_HCControl_noByteSwapData);
2373 
2374 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2375 	reg_write(ohci, OHCI1394_LinkControlSet,
2376 		  OHCI1394_LinkControl_cycleTimerEnable |
2377 		  OHCI1394_LinkControl_cycleMaster);
2378 
2379 	reg_write(ohci, OHCI1394_ATRetries,
2380 		  OHCI1394_MAX_AT_REQ_RETRIES |
2381 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2382 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2383 		  (200 << 16));
2384 
2385 	ohci->bus_time_running = false;
2386 
2387 	for (i = 0; i < 32; i++)
2388 		if (ohci->ir_context_support & (1 << i))
2389 			reg_write(ohci, OHCI1394_IsoRcvContextControlClear(i),
2390 				  IR_CONTEXT_MULTI_CHANNEL_MODE);
2391 
2392 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2393 	if (version >= OHCI_VERSION_1_1) {
2394 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2395 			  0xfffffffe);
2396 		card->broadcast_channel_auto_allocated = true;
2397 	}
2398 
2399 	/* Get implemented bits of the priority arbitration request counter. */
2400 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2401 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2402 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2403 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2404 
2405 	reg_write(ohci, OHCI1394_PhyUpperBound, FW_MAX_PHYSICAL_RANGE >> 16);
2406 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2407 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2408 
2409 	ret = configure_1394a_enhancements(ohci);
2410 	if (ret < 0)
2411 		return ret;
2412 
2413 	/* Activate link_on bit and contender bit in our self ID packets.*/
2414 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2415 	if (ret < 0)
2416 		return ret;
2417 
2418 	/*
2419 	 * When the link is not yet enabled, the atomic config rom
2420 	 * update mechanism described below in ohci_set_config_rom()
2421 	 * is not active.  We have to update ConfigRomHeader and
2422 	 * BusOptions manually, and the write to ConfigROMmap takes
2423 	 * effect immediately.  We tie this to the enabling of the
2424 	 * link, so we have a valid config rom before enabling - the
2425 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2426 	 * values before enabling.
2427 	 *
2428 	 * However, when the ConfigROMmap is written, some controllers
2429 	 * always read back quadlets 0 and 2 from the config rom to
2430 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2431 	 * They shouldn't do that in this initial case where the link
2432 	 * isn't enabled.  This means we have to use the same
2433 	 * workaround here, setting the bus header to 0 and then write
2434 	 * the right values in the bus reset tasklet.
2435 	 */
2436 
2437 	if (config_rom) {
2438 		ohci->next_config_rom = dmam_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2439 							    &ohci->next_config_rom_bus, GFP_KERNEL);
2440 		if (ohci->next_config_rom == NULL)
2441 			return -ENOMEM;
2442 
2443 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2444 	} else {
2445 		/*
2446 		 * In the suspend case, config_rom is NULL, which
2447 		 * means that we just reuse the old config rom.
2448 		 */
2449 		ohci->next_config_rom = ohci->config_rom;
2450 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2451 	}
2452 
2453 	ohci->next_header = ohci->next_config_rom[0];
2454 	ohci->next_config_rom[0] = 0;
2455 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2456 	reg_write(ohci, OHCI1394_BusOptions,
2457 		  be32_to_cpu(ohci->next_config_rom[2]));
2458 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2459 
2460 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2461 
2462 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2463 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2464 		OHCI1394_isochTx | OHCI1394_isochRx |
2465 		OHCI1394_postedWriteErr |
2466 		OHCI1394_selfIDComplete |
2467 		OHCI1394_regAccessFail |
2468 		OHCI1394_cycleInconsistent |
2469 		OHCI1394_unrecoverableError |
2470 		OHCI1394_cycleTooLong |
2471 		OHCI1394_masterIntEnable;
2472 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2473 		irqs |= OHCI1394_busReset;
2474 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2475 
2476 	reg_write(ohci, OHCI1394_HCControlSet,
2477 		  OHCI1394_HCControl_linkEnable |
2478 		  OHCI1394_HCControl_BIBimageValid);
2479 
2480 	reg_write(ohci, OHCI1394_LinkControlSet,
2481 		  OHCI1394_LinkControl_rcvSelfID |
2482 		  OHCI1394_LinkControl_rcvPhyPkt);
2483 
2484 	ar_context_run(&ohci->ar_request_ctx);
2485 	ar_context_run(&ohci->ar_response_ctx);
2486 
2487 	flush_writes(ohci);
2488 
2489 	/* We are ready to go, reset bus to finish initialization. */
2490 	fw_schedule_bus_reset(&ohci->card, false, true);
2491 
2492 	return 0;
2493 }
2494 
2495 static int ohci_set_config_rom(struct fw_card *card,
2496 			       const __be32 *config_rom, size_t length)
2497 {
2498 	struct fw_ohci *ohci;
2499 	__be32 *next_config_rom;
2500 	dma_addr_t next_config_rom_bus;
2501 
2502 	ohci = fw_ohci(card);
2503 
2504 	/*
2505 	 * When the OHCI controller is enabled, the config rom update
2506 	 * mechanism is a bit tricky, but easy enough to use.  See
2507 	 * section 5.5.6 in the OHCI specification.
2508 	 *
2509 	 * The OHCI controller caches the new config rom address in a
2510 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2511 	 * for the changes to take place.  When the bus reset is
2512 	 * detected, the controller loads the new values for the
2513 	 * ConfigRomHeader and BusOptions registers from the specified
2514 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2515 	 * shadow register. All automatically and atomically.
2516 	 *
2517 	 * Now, there's a twist to this story.  The automatic load of
2518 	 * ConfigRomHeader and BusOptions doesn't honor the
2519 	 * noByteSwapData bit, so with a be32 config rom, the
2520 	 * controller will load be32 values in to these registers
2521 	 * during the atomic update, even on litte endian
2522 	 * architectures.  The workaround we use is to put a 0 in the
2523 	 * header quadlet; 0 is endian agnostic and means that the
2524 	 * config rom isn't ready yet.  In the bus reset tasklet we
2525 	 * then set up the real values for the two registers.
2526 	 *
2527 	 * We use ohci->lock to avoid racing with the code that sets
2528 	 * ohci->next_config_rom to NULL (see bus_reset_work).
2529 	 */
2530 
2531 	next_config_rom = dmam_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2532 					      &next_config_rom_bus, GFP_KERNEL);
2533 	if (next_config_rom == NULL)
2534 		return -ENOMEM;
2535 
2536 	spin_lock_irq(&ohci->lock);
2537 
2538 	/*
2539 	 * If there is not an already pending config_rom update,
2540 	 * push our new allocation into the ohci->next_config_rom
2541 	 * and then mark the local variable as null so that we
2542 	 * won't deallocate the new buffer.
2543 	 *
2544 	 * OTOH, if there is a pending config_rom update, just
2545 	 * use that buffer with the new config_rom data, and
2546 	 * let this routine free the unused DMA allocation.
2547 	 */
2548 
2549 	if (ohci->next_config_rom == NULL) {
2550 		ohci->next_config_rom = next_config_rom;
2551 		ohci->next_config_rom_bus = next_config_rom_bus;
2552 		next_config_rom = NULL;
2553 	}
2554 
2555 	copy_config_rom(ohci->next_config_rom, config_rom, length);
2556 
2557 	ohci->next_header = config_rom[0];
2558 	ohci->next_config_rom[0] = 0;
2559 
2560 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2561 
2562 	spin_unlock_irq(&ohci->lock);
2563 
2564 	/* If we didn't use the DMA allocation, delete it. */
2565 	if (next_config_rom != NULL) {
2566 		dmam_free_coherent(ohci->card.device, CONFIG_ROM_SIZE, next_config_rom,
2567 				   next_config_rom_bus);
2568 	}
2569 
2570 	/*
2571 	 * Now initiate a bus reset to have the changes take
2572 	 * effect. We clean up the old config rom memory and DMA
2573 	 * mappings in the bus reset tasklet, since the OHCI
2574 	 * controller could need to access it before the bus reset
2575 	 * takes effect.
2576 	 */
2577 
2578 	fw_schedule_bus_reset(&ohci->card, true, true);
2579 
2580 	return 0;
2581 }
2582 
2583 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2584 {
2585 	struct fw_ohci *ohci = fw_ohci(card);
2586 
2587 	at_context_transmit(&ohci->at_request_ctx, packet);
2588 }
2589 
2590 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2591 {
2592 	struct fw_ohci *ohci = fw_ohci(card);
2593 
2594 	at_context_transmit(&ohci->at_response_ctx, packet);
2595 }
2596 
2597 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2598 {
2599 	struct fw_ohci *ohci = fw_ohci(card);
2600 	struct context *ctx = &ohci->at_request_ctx;
2601 	struct driver_data *driver_data = packet->driver_data;
2602 	int ret = -ENOENT;
2603 
2604 	tasklet_disable_in_atomic(&ctx->tasklet);
2605 
2606 	if (packet->ack != 0)
2607 		goto out;
2608 
2609 	if (packet->payload_mapped)
2610 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2611 				 packet->payload_length, DMA_TO_DEVICE);
2612 
2613 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, 0x20);
2614 	driver_data->packet = NULL;
2615 	packet->ack = RCODE_CANCELLED;
2616 
2617 	// Timestamping on behalf of the hardware.
2618 	packet->timestamp = cycle_time_to_ohci_tstamp(get_cycle_time(ohci));
2619 
2620 	packet->callback(packet, &ohci->card, packet->ack);
2621 	ret = 0;
2622  out:
2623 	tasklet_enable(&ctx->tasklet);
2624 
2625 	return ret;
2626 }
2627 
2628 static int ohci_enable_phys_dma(struct fw_card *card,
2629 				int node_id, int generation)
2630 {
2631 	struct fw_ohci *ohci = fw_ohci(card);
2632 	unsigned long flags;
2633 	int n, ret = 0;
2634 
2635 	if (param_remote_dma)
2636 		return 0;
2637 
2638 	/*
2639 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2640 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2641 	 */
2642 
2643 	spin_lock_irqsave(&ohci->lock, flags);
2644 
2645 	if (ohci->generation != generation) {
2646 		ret = -ESTALE;
2647 		goto out;
2648 	}
2649 
2650 	/*
2651 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2652 	 * enabled for _all_ nodes on remote buses.
2653 	 */
2654 
2655 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2656 	if (n < 32)
2657 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2658 	else
2659 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2660 
2661 	flush_writes(ohci);
2662  out:
2663 	spin_unlock_irqrestore(&ohci->lock, flags);
2664 
2665 	return ret;
2666 }
2667 
2668 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2669 {
2670 	struct fw_ohci *ohci = fw_ohci(card);
2671 	unsigned long flags;
2672 	u32 value;
2673 
2674 	switch (csr_offset) {
2675 	case CSR_STATE_CLEAR:
2676 	case CSR_STATE_SET:
2677 		if (ohci->is_root &&
2678 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2679 		     OHCI1394_LinkControl_cycleMaster))
2680 			value = CSR_STATE_BIT_CMSTR;
2681 		else
2682 			value = 0;
2683 		if (ohci->csr_state_setclear_abdicate)
2684 			value |= CSR_STATE_BIT_ABDICATE;
2685 
2686 		return value;
2687 
2688 	case CSR_NODE_IDS:
2689 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2690 
2691 	case CSR_CYCLE_TIME:
2692 		return get_cycle_time(ohci);
2693 
2694 	case CSR_BUS_TIME:
2695 		/*
2696 		 * We might be called just after the cycle timer has wrapped
2697 		 * around but just before the cycle64Seconds handler, so we
2698 		 * better check here, too, if the bus time needs to be updated.
2699 		 */
2700 		spin_lock_irqsave(&ohci->lock, flags);
2701 		value = update_bus_time(ohci);
2702 		spin_unlock_irqrestore(&ohci->lock, flags);
2703 		return value;
2704 
2705 	case CSR_BUSY_TIMEOUT:
2706 		value = reg_read(ohci, OHCI1394_ATRetries);
2707 		return (value >> 4) & 0x0ffff00f;
2708 
2709 	case CSR_PRIORITY_BUDGET:
2710 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2711 			(ohci->pri_req_max << 8);
2712 
2713 	default:
2714 		WARN_ON(1);
2715 		return 0;
2716 	}
2717 }
2718 
2719 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2720 {
2721 	struct fw_ohci *ohci = fw_ohci(card);
2722 	unsigned long flags;
2723 
2724 	switch (csr_offset) {
2725 	case CSR_STATE_CLEAR:
2726 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2727 			reg_write(ohci, OHCI1394_LinkControlClear,
2728 				  OHCI1394_LinkControl_cycleMaster);
2729 			flush_writes(ohci);
2730 		}
2731 		if (value & CSR_STATE_BIT_ABDICATE)
2732 			ohci->csr_state_setclear_abdicate = false;
2733 		break;
2734 
2735 	case CSR_STATE_SET:
2736 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2737 			reg_write(ohci, OHCI1394_LinkControlSet,
2738 				  OHCI1394_LinkControl_cycleMaster);
2739 			flush_writes(ohci);
2740 		}
2741 		if (value & CSR_STATE_BIT_ABDICATE)
2742 			ohci->csr_state_setclear_abdicate = true;
2743 		break;
2744 
2745 	case CSR_NODE_IDS:
2746 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2747 		flush_writes(ohci);
2748 		break;
2749 
2750 	case CSR_CYCLE_TIME:
2751 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2752 		reg_write(ohci, OHCI1394_IntEventSet,
2753 			  OHCI1394_cycleInconsistent);
2754 		flush_writes(ohci);
2755 		break;
2756 
2757 	case CSR_BUS_TIME:
2758 		spin_lock_irqsave(&ohci->lock, flags);
2759 		ohci->bus_time = (update_bus_time(ohci) & 0x40) |
2760 		                 (value & ~0x7f);
2761 		spin_unlock_irqrestore(&ohci->lock, flags);
2762 		break;
2763 
2764 	case CSR_BUSY_TIMEOUT:
2765 		value = (value & 0xf) | ((value & 0xf) << 4) |
2766 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2767 		reg_write(ohci, OHCI1394_ATRetries, value);
2768 		flush_writes(ohci);
2769 		break;
2770 
2771 	case CSR_PRIORITY_BUDGET:
2772 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2773 		flush_writes(ohci);
2774 		break;
2775 
2776 	default:
2777 		WARN_ON(1);
2778 		break;
2779 	}
2780 }
2781 
2782 static void flush_iso_completions(struct iso_context *ctx)
2783 {
2784 	ctx->base.callback.sc(&ctx->base, ctx->last_timestamp,
2785 			      ctx->header_length, ctx->header,
2786 			      ctx->base.callback_data);
2787 	ctx->header_length = 0;
2788 }
2789 
2790 static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
2791 {
2792 	u32 *ctx_hdr;
2793 
2794 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
2795 		if (ctx->base.drop_overflow_headers)
2796 			return;
2797 		flush_iso_completions(ctx);
2798 	}
2799 
2800 	ctx_hdr = ctx->header + ctx->header_length;
2801 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
2802 
2803 	/*
2804 	 * The two iso header quadlets are byteswapped to little
2805 	 * endian by the controller, but we want to present them
2806 	 * as big endian for consistency with the bus endianness.
2807 	 */
2808 	if (ctx->base.header_size > 0)
2809 		ctx_hdr[0] = swab32(dma_hdr[1]); /* iso packet header */
2810 	if (ctx->base.header_size > 4)
2811 		ctx_hdr[1] = swab32(dma_hdr[0]); /* timestamp */
2812 	if (ctx->base.header_size > 8)
2813 		memcpy(&ctx_hdr[2], &dma_hdr[2], ctx->base.header_size - 8);
2814 	ctx->header_length += ctx->base.header_size;
2815 }
2816 
2817 static int handle_ir_packet_per_buffer(struct context *context,
2818 				       struct descriptor *d,
2819 				       struct descriptor *last)
2820 {
2821 	struct iso_context *ctx =
2822 		container_of(context, struct iso_context, context);
2823 	struct descriptor *pd;
2824 	u32 buffer_dma;
2825 
2826 	for (pd = d; pd <= last; pd++)
2827 		if (pd->transfer_status)
2828 			break;
2829 	if (pd > last)
2830 		/* Descriptor(s) not done yet, stop iteration */
2831 		return 0;
2832 
2833 	while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
2834 		d++;
2835 		buffer_dma = le32_to_cpu(d->data_address);
2836 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2837 					      buffer_dma & PAGE_MASK,
2838 					      buffer_dma & ~PAGE_MASK,
2839 					      le16_to_cpu(d->req_count),
2840 					      DMA_FROM_DEVICE);
2841 	}
2842 
2843 	copy_iso_headers(ctx, (u32 *) (last + 1));
2844 
2845 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2846 		flush_iso_completions(ctx);
2847 
2848 	return 1;
2849 }
2850 
2851 /* d == last because each descriptor block is only a single descriptor. */
2852 static int handle_ir_buffer_fill(struct context *context,
2853 				 struct descriptor *d,
2854 				 struct descriptor *last)
2855 {
2856 	struct iso_context *ctx =
2857 		container_of(context, struct iso_context, context);
2858 	unsigned int req_count, res_count, completed;
2859 	u32 buffer_dma;
2860 
2861 	req_count = le16_to_cpu(last->req_count);
2862 	res_count = le16_to_cpu(READ_ONCE(last->res_count));
2863 	completed = req_count - res_count;
2864 	buffer_dma = le32_to_cpu(last->data_address);
2865 
2866 	if (completed > 0) {
2867 		ctx->mc_buffer_bus = buffer_dma;
2868 		ctx->mc_completed = completed;
2869 	}
2870 
2871 	if (res_count != 0)
2872 		/* Descriptor(s) not done yet, stop iteration */
2873 		return 0;
2874 
2875 	dma_sync_single_range_for_cpu(context->ohci->card.device,
2876 				      buffer_dma & PAGE_MASK,
2877 				      buffer_dma & ~PAGE_MASK,
2878 				      completed, DMA_FROM_DEVICE);
2879 
2880 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) {
2881 		ctx->base.callback.mc(&ctx->base,
2882 				      buffer_dma + completed,
2883 				      ctx->base.callback_data);
2884 		ctx->mc_completed = 0;
2885 	}
2886 
2887 	return 1;
2888 }
2889 
2890 static void flush_ir_buffer_fill(struct iso_context *ctx)
2891 {
2892 	dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
2893 				      ctx->mc_buffer_bus & PAGE_MASK,
2894 				      ctx->mc_buffer_bus & ~PAGE_MASK,
2895 				      ctx->mc_completed, DMA_FROM_DEVICE);
2896 
2897 	ctx->base.callback.mc(&ctx->base,
2898 			      ctx->mc_buffer_bus + ctx->mc_completed,
2899 			      ctx->base.callback_data);
2900 	ctx->mc_completed = 0;
2901 }
2902 
2903 static inline void sync_it_packet_for_cpu(struct context *context,
2904 					  struct descriptor *pd)
2905 {
2906 	__le16 control;
2907 	u32 buffer_dma;
2908 
2909 	/* only packets beginning with OUTPUT_MORE* have data buffers */
2910 	if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2911 		return;
2912 
2913 	/* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
2914 	pd += 2;
2915 
2916 	/*
2917 	 * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
2918 	 * data buffer is in the context program's coherent page and must not
2919 	 * be synced.
2920 	 */
2921 	if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
2922 	    (context->current_bus          & PAGE_MASK)) {
2923 		if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2924 			return;
2925 		pd++;
2926 	}
2927 
2928 	do {
2929 		buffer_dma = le32_to_cpu(pd->data_address);
2930 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2931 					      buffer_dma & PAGE_MASK,
2932 					      buffer_dma & ~PAGE_MASK,
2933 					      le16_to_cpu(pd->req_count),
2934 					      DMA_TO_DEVICE);
2935 		control = pd->control;
2936 		pd++;
2937 	} while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
2938 }
2939 
2940 static int handle_it_packet(struct context *context,
2941 			    struct descriptor *d,
2942 			    struct descriptor *last)
2943 {
2944 	struct iso_context *ctx =
2945 		container_of(context, struct iso_context, context);
2946 	struct descriptor *pd;
2947 	__be32 *ctx_hdr;
2948 
2949 	for (pd = d; pd <= last; pd++)
2950 		if (pd->transfer_status)
2951 			break;
2952 	if (pd > last)
2953 		/* Descriptor(s) not done yet, stop iteration */
2954 		return 0;
2955 
2956 	sync_it_packet_for_cpu(context, d);
2957 
2958 	if (ctx->header_length + 4 > PAGE_SIZE) {
2959 		if (ctx->base.drop_overflow_headers)
2960 			return 1;
2961 		flush_iso_completions(ctx);
2962 	}
2963 
2964 	ctx_hdr = ctx->header + ctx->header_length;
2965 	ctx->last_timestamp = le16_to_cpu(last->res_count);
2966 	/* Present this value as big-endian to match the receive code */
2967 	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
2968 			       le16_to_cpu(pd->res_count));
2969 	ctx->header_length += 4;
2970 
2971 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2972 		flush_iso_completions(ctx);
2973 
2974 	return 1;
2975 }
2976 
2977 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2978 {
2979 	u32 hi = channels >> 32, lo = channels;
2980 
2981 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2982 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2983 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2984 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2985 	ohci->mc_channels = channels;
2986 }
2987 
2988 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2989 				int type, int channel, size_t header_size)
2990 {
2991 	struct fw_ohci *ohci = fw_ohci(card);
2992 	struct iso_context *ctx;
2993 	descriptor_callback_t callback;
2994 	u64 *channels;
2995 	u32 *mask, regs;
2996 	int index, ret = -EBUSY;
2997 
2998 	spin_lock_irq(&ohci->lock);
2999 
3000 	switch (type) {
3001 	case FW_ISO_CONTEXT_TRANSMIT:
3002 		mask     = &ohci->it_context_mask;
3003 		callback = handle_it_packet;
3004 		index    = ffs(*mask) - 1;
3005 		if (index >= 0) {
3006 			*mask &= ~(1 << index);
3007 			regs = OHCI1394_IsoXmitContextBase(index);
3008 			ctx  = &ohci->it_context_list[index];
3009 		}
3010 		break;
3011 
3012 	case FW_ISO_CONTEXT_RECEIVE:
3013 		channels = &ohci->ir_context_channels;
3014 		mask     = &ohci->ir_context_mask;
3015 		callback = handle_ir_packet_per_buffer;
3016 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
3017 		if (index >= 0) {
3018 			*channels &= ~(1ULL << channel);
3019 			*mask     &= ~(1 << index);
3020 			regs = OHCI1394_IsoRcvContextBase(index);
3021 			ctx  = &ohci->ir_context_list[index];
3022 		}
3023 		break;
3024 
3025 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3026 		mask     = &ohci->ir_context_mask;
3027 		callback = handle_ir_buffer_fill;
3028 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
3029 		if (index >= 0) {
3030 			ohci->mc_allocated = true;
3031 			*mask &= ~(1 << index);
3032 			regs = OHCI1394_IsoRcvContextBase(index);
3033 			ctx  = &ohci->ir_context_list[index];
3034 		}
3035 		break;
3036 
3037 	default:
3038 		index = -1;
3039 		ret = -ENOSYS;
3040 	}
3041 
3042 	spin_unlock_irq(&ohci->lock);
3043 
3044 	if (index < 0)
3045 		return ERR_PTR(ret);
3046 
3047 	memset(ctx, 0, sizeof(*ctx));
3048 	ctx->header_length = 0;
3049 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
3050 	if (ctx->header == NULL) {
3051 		ret = -ENOMEM;
3052 		goto out;
3053 	}
3054 	ret = context_init(&ctx->context, ohci, regs, callback);
3055 	if (ret < 0)
3056 		goto out_with_header;
3057 
3058 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
3059 		set_multichannel_mask(ohci, 0);
3060 		ctx->mc_completed = 0;
3061 	}
3062 
3063 	return &ctx->base;
3064 
3065  out_with_header:
3066 	free_page((unsigned long)ctx->header);
3067  out:
3068 	spin_lock_irq(&ohci->lock);
3069 
3070 	switch (type) {
3071 	case FW_ISO_CONTEXT_RECEIVE:
3072 		*channels |= 1ULL << channel;
3073 		break;
3074 
3075 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3076 		ohci->mc_allocated = false;
3077 		break;
3078 	}
3079 	*mask |= 1 << index;
3080 
3081 	spin_unlock_irq(&ohci->lock);
3082 
3083 	return ERR_PTR(ret);
3084 }
3085 
3086 static int ohci_start_iso(struct fw_iso_context *base,
3087 			  s32 cycle, u32 sync, u32 tags)
3088 {
3089 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3090 	struct fw_ohci *ohci = ctx->context.ohci;
3091 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
3092 	int index;
3093 
3094 	/* the controller cannot start without any queued packets */
3095 	if (ctx->context.last->branch_address == 0)
3096 		return -ENODATA;
3097 
3098 	switch (ctx->base.type) {
3099 	case FW_ISO_CONTEXT_TRANSMIT:
3100 		index = ctx - ohci->it_context_list;
3101 		match = 0;
3102 		if (cycle >= 0)
3103 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
3104 				(cycle & 0x7fff) << 16;
3105 
3106 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
3107 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
3108 		context_run(&ctx->context, match);
3109 		break;
3110 
3111 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3112 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
3113 		fallthrough;
3114 	case FW_ISO_CONTEXT_RECEIVE:
3115 		index = ctx - ohci->ir_context_list;
3116 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
3117 		if (cycle >= 0) {
3118 			match |= (cycle & 0x07fff) << 12;
3119 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
3120 		}
3121 
3122 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
3123 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
3124 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
3125 		context_run(&ctx->context, control);
3126 
3127 		ctx->sync = sync;
3128 		ctx->tags = tags;
3129 
3130 		break;
3131 	}
3132 
3133 	return 0;
3134 }
3135 
3136 static int ohci_stop_iso(struct fw_iso_context *base)
3137 {
3138 	struct fw_ohci *ohci = fw_ohci(base->card);
3139 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3140 	int index;
3141 
3142 	switch (ctx->base.type) {
3143 	case FW_ISO_CONTEXT_TRANSMIT:
3144 		index = ctx - ohci->it_context_list;
3145 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
3146 		break;
3147 
3148 	case FW_ISO_CONTEXT_RECEIVE:
3149 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3150 		index = ctx - ohci->ir_context_list;
3151 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
3152 		break;
3153 	}
3154 	flush_writes(ohci);
3155 	context_stop(&ctx->context);
3156 	tasklet_kill(&ctx->context.tasklet);
3157 
3158 	return 0;
3159 }
3160 
3161 static void ohci_free_iso_context(struct fw_iso_context *base)
3162 {
3163 	struct fw_ohci *ohci = fw_ohci(base->card);
3164 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3165 	unsigned long flags;
3166 	int index;
3167 
3168 	ohci_stop_iso(base);
3169 	context_release(&ctx->context);
3170 	free_page((unsigned long)ctx->header);
3171 
3172 	spin_lock_irqsave(&ohci->lock, flags);
3173 
3174 	switch (base->type) {
3175 	case FW_ISO_CONTEXT_TRANSMIT:
3176 		index = ctx - ohci->it_context_list;
3177 		ohci->it_context_mask |= 1 << index;
3178 		break;
3179 
3180 	case FW_ISO_CONTEXT_RECEIVE:
3181 		index = ctx - ohci->ir_context_list;
3182 		ohci->ir_context_mask |= 1 << index;
3183 		ohci->ir_context_channels |= 1ULL << base->channel;
3184 		break;
3185 
3186 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3187 		index = ctx - ohci->ir_context_list;
3188 		ohci->ir_context_mask |= 1 << index;
3189 		ohci->ir_context_channels |= ohci->mc_channels;
3190 		ohci->mc_channels = 0;
3191 		ohci->mc_allocated = false;
3192 		break;
3193 	}
3194 
3195 	spin_unlock_irqrestore(&ohci->lock, flags);
3196 }
3197 
3198 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
3199 {
3200 	struct fw_ohci *ohci = fw_ohci(base->card);
3201 	unsigned long flags;
3202 	int ret;
3203 
3204 	switch (base->type) {
3205 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3206 
3207 		spin_lock_irqsave(&ohci->lock, flags);
3208 
3209 		/* Don't allow multichannel to grab other contexts' channels. */
3210 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
3211 			*channels = ohci->ir_context_channels;
3212 			ret = -EBUSY;
3213 		} else {
3214 			set_multichannel_mask(ohci, *channels);
3215 			ret = 0;
3216 		}
3217 
3218 		spin_unlock_irqrestore(&ohci->lock, flags);
3219 
3220 		break;
3221 	default:
3222 		ret = -EINVAL;
3223 	}
3224 
3225 	return ret;
3226 }
3227 
3228 #ifdef CONFIG_PM
3229 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
3230 {
3231 	int i;
3232 	struct iso_context *ctx;
3233 
3234 	for (i = 0 ; i < ohci->n_ir ; i++) {
3235 		ctx = &ohci->ir_context_list[i];
3236 		if (ctx->context.running)
3237 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3238 	}
3239 
3240 	for (i = 0 ; i < ohci->n_it ; i++) {
3241 		ctx = &ohci->it_context_list[i];
3242 		if (ctx->context.running)
3243 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3244 	}
3245 }
3246 #endif
3247 
3248 static int queue_iso_transmit(struct iso_context *ctx,
3249 			      struct fw_iso_packet *packet,
3250 			      struct fw_iso_buffer *buffer,
3251 			      unsigned long payload)
3252 {
3253 	struct descriptor *d, *last, *pd;
3254 	struct fw_iso_packet *p;
3255 	__le32 *header;
3256 	dma_addr_t d_bus, page_bus;
3257 	u32 z, header_z, payload_z, irq;
3258 	u32 payload_index, payload_end_index, next_page_index;
3259 	int page, end_page, i, length, offset;
3260 
3261 	p = packet;
3262 	payload_index = payload;
3263 
3264 	if (p->skip)
3265 		z = 1;
3266 	else
3267 		z = 2;
3268 	if (p->header_length > 0)
3269 		z++;
3270 
3271 	/* Determine the first page the payload isn't contained in. */
3272 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
3273 	if (p->payload_length > 0)
3274 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
3275 	else
3276 		payload_z = 0;
3277 
3278 	z += payload_z;
3279 
3280 	/* Get header size in number of descriptors. */
3281 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
3282 
3283 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
3284 	if (d == NULL)
3285 		return -ENOMEM;
3286 
3287 	if (!p->skip) {
3288 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
3289 		d[0].req_count = cpu_to_le16(8);
3290 		/*
3291 		 * Link the skip address to this descriptor itself.  This causes
3292 		 * a context to skip a cycle whenever lost cycles or FIFO
3293 		 * overruns occur, without dropping the data.  The application
3294 		 * should then decide whether this is an error condition or not.
3295 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
3296 		 */
3297 		d[0].branch_address = cpu_to_le32(d_bus | z);
3298 
3299 		header = (__le32 *) &d[1];
3300 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
3301 					IT_HEADER_TAG(p->tag) |
3302 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
3303 					IT_HEADER_CHANNEL(ctx->base.channel) |
3304 					IT_HEADER_SPEED(ctx->base.speed));
3305 		header[1] =
3306 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
3307 							  p->payload_length));
3308 	}
3309 
3310 	if (p->header_length > 0) {
3311 		d[2].req_count    = cpu_to_le16(p->header_length);
3312 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
3313 		memcpy(&d[z], p->header, p->header_length);
3314 	}
3315 
3316 	pd = d + z - payload_z;
3317 	payload_end_index = payload_index + p->payload_length;
3318 	for (i = 0; i < payload_z; i++) {
3319 		page               = payload_index >> PAGE_SHIFT;
3320 		offset             = payload_index & ~PAGE_MASK;
3321 		next_page_index    = (page + 1) << PAGE_SHIFT;
3322 		length             =
3323 			min(next_page_index, payload_end_index) - payload_index;
3324 		pd[i].req_count    = cpu_to_le16(length);
3325 
3326 		page_bus = page_private(buffer->pages[page]);
3327 		pd[i].data_address = cpu_to_le32(page_bus + offset);
3328 
3329 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3330 						 page_bus, offset, length,
3331 						 DMA_TO_DEVICE);
3332 
3333 		payload_index += length;
3334 	}
3335 
3336 	if (p->interrupt)
3337 		irq = DESCRIPTOR_IRQ_ALWAYS;
3338 	else
3339 		irq = DESCRIPTOR_NO_IRQ;
3340 
3341 	last = z == 2 ? d : d + z - 1;
3342 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
3343 				     DESCRIPTOR_STATUS |
3344 				     DESCRIPTOR_BRANCH_ALWAYS |
3345 				     irq);
3346 
3347 	context_append(&ctx->context, d, z, header_z);
3348 
3349 	return 0;
3350 }
3351 
3352 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
3353 				       struct fw_iso_packet *packet,
3354 				       struct fw_iso_buffer *buffer,
3355 				       unsigned long payload)
3356 {
3357 	struct device *device = ctx->context.ohci->card.device;
3358 	struct descriptor *d, *pd;
3359 	dma_addr_t d_bus, page_bus;
3360 	u32 z, header_z, rest;
3361 	int i, j, length;
3362 	int page, offset, packet_count, header_size, payload_per_buffer;
3363 
3364 	/*
3365 	 * The OHCI controller puts the isochronous header and trailer in the
3366 	 * buffer, so we need at least 8 bytes.
3367 	 */
3368 	packet_count = packet->header_length / ctx->base.header_size;
3369 	header_size  = max(ctx->base.header_size, (size_t)8);
3370 
3371 	/* Get header size in number of descriptors. */
3372 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
3373 	page     = payload >> PAGE_SHIFT;
3374 	offset   = payload & ~PAGE_MASK;
3375 	payload_per_buffer = packet->payload_length / packet_count;
3376 
3377 	for (i = 0; i < packet_count; i++) {
3378 		/* d points to the header descriptor */
3379 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
3380 		d = context_get_descriptors(&ctx->context,
3381 				z + header_z, &d_bus);
3382 		if (d == NULL)
3383 			return -ENOMEM;
3384 
3385 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3386 					      DESCRIPTOR_INPUT_MORE);
3387 		if (packet->skip && i == 0)
3388 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3389 		d->req_count    = cpu_to_le16(header_size);
3390 		d->res_count    = d->req_count;
3391 		d->transfer_status = 0;
3392 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3393 
3394 		rest = payload_per_buffer;
3395 		pd = d;
3396 		for (j = 1; j < z; j++) {
3397 			pd++;
3398 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3399 						  DESCRIPTOR_INPUT_MORE);
3400 
3401 			if (offset + rest < PAGE_SIZE)
3402 				length = rest;
3403 			else
3404 				length = PAGE_SIZE - offset;
3405 			pd->req_count = cpu_to_le16(length);
3406 			pd->res_count = pd->req_count;
3407 			pd->transfer_status = 0;
3408 
3409 			page_bus = page_private(buffer->pages[page]);
3410 			pd->data_address = cpu_to_le32(page_bus + offset);
3411 
3412 			dma_sync_single_range_for_device(device, page_bus,
3413 							 offset, length,
3414 							 DMA_FROM_DEVICE);
3415 
3416 			offset = (offset + length) & ~PAGE_MASK;
3417 			rest -= length;
3418 			if (offset == 0)
3419 				page++;
3420 		}
3421 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3422 					  DESCRIPTOR_INPUT_LAST |
3423 					  DESCRIPTOR_BRANCH_ALWAYS);
3424 		if (packet->interrupt && i == packet_count - 1)
3425 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3426 
3427 		context_append(&ctx->context, d, z, header_z);
3428 	}
3429 
3430 	return 0;
3431 }
3432 
3433 static int queue_iso_buffer_fill(struct iso_context *ctx,
3434 				 struct fw_iso_packet *packet,
3435 				 struct fw_iso_buffer *buffer,
3436 				 unsigned long payload)
3437 {
3438 	struct descriptor *d;
3439 	dma_addr_t d_bus, page_bus;
3440 	int page, offset, rest, z, i, length;
3441 
3442 	page   = payload >> PAGE_SHIFT;
3443 	offset = payload & ~PAGE_MASK;
3444 	rest   = packet->payload_length;
3445 
3446 	/* We need one descriptor for each page in the buffer. */
3447 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3448 
3449 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3450 		return -EFAULT;
3451 
3452 	for (i = 0; i < z; i++) {
3453 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3454 		if (d == NULL)
3455 			return -ENOMEM;
3456 
3457 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3458 					 DESCRIPTOR_BRANCH_ALWAYS);
3459 		if (packet->skip && i == 0)
3460 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3461 		if (packet->interrupt && i == z - 1)
3462 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3463 
3464 		if (offset + rest < PAGE_SIZE)
3465 			length = rest;
3466 		else
3467 			length = PAGE_SIZE - offset;
3468 		d->req_count = cpu_to_le16(length);
3469 		d->res_count = d->req_count;
3470 		d->transfer_status = 0;
3471 
3472 		page_bus = page_private(buffer->pages[page]);
3473 		d->data_address = cpu_to_le32(page_bus + offset);
3474 
3475 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3476 						 page_bus, offset, length,
3477 						 DMA_FROM_DEVICE);
3478 
3479 		rest -= length;
3480 		offset = 0;
3481 		page++;
3482 
3483 		context_append(&ctx->context, d, 1, 0);
3484 	}
3485 
3486 	return 0;
3487 }
3488 
3489 static int ohci_queue_iso(struct fw_iso_context *base,
3490 			  struct fw_iso_packet *packet,
3491 			  struct fw_iso_buffer *buffer,
3492 			  unsigned long payload)
3493 {
3494 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3495 	unsigned long flags;
3496 	int ret = -ENOSYS;
3497 
3498 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3499 	switch (base->type) {
3500 	case FW_ISO_CONTEXT_TRANSMIT:
3501 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3502 		break;
3503 	case FW_ISO_CONTEXT_RECEIVE:
3504 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3505 		break;
3506 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3507 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3508 		break;
3509 	}
3510 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3511 
3512 	return ret;
3513 }
3514 
3515 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3516 {
3517 	struct context *ctx =
3518 			&container_of(base, struct iso_context, base)->context;
3519 
3520 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3521 }
3522 
3523 static int ohci_flush_iso_completions(struct fw_iso_context *base)
3524 {
3525 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3526 	int ret = 0;
3527 
3528 	tasklet_disable_in_atomic(&ctx->context.tasklet);
3529 
3530 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
3531 		context_tasklet((unsigned long)&ctx->context);
3532 
3533 		switch (base->type) {
3534 		case FW_ISO_CONTEXT_TRANSMIT:
3535 		case FW_ISO_CONTEXT_RECEIVE:
3536 			if (ctx->header_length != 0)
3537 				flush_iso_completions(ctx);
3538 			break;
3539 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3540 			if (ctx->mc_completed != 0)
3541 				flush_ir_buffer_fill(ctx);
3542 			break;
3543 		default:
3544 			ret = -ENOSYS;
3545 		}
3546 
3547 		clear_bit_unlock(0, &ctx->flushing_completions);
3548 		smp_mb__after_atomic();
3549 	}
3550 
3551 	tasklet_enable(&ctx->context.tasklet);
3552 
3553 	return ret;
3554 }
3555 
3556 static const struct fw_card_driver ohci_driver = {
3557 	.enable			= ohci_enable,
3558 	.read_phy_reg		= ohci_read_phy_reg,
3559 	.update_phy_reg		= ohci_update_phy_reg,
3560 	.set_config_rom		= ohci_set_config_rom,
3561 	.send_request		= ohci_send_request,
3562 	.send_response		= ohci_send_response,
3563 	.cancel_packet		= ohci_cancel_packet,
3564 	.enable_phys_dma	= ohci_enable_phys_dma,
3565 	.read_csr		= ohci_read_csr,
3566 	.write_csr		= ohci_write_csr,
3567 
3568 	.allocate_iso_context	= ohci_allocate_iso_context,
3569 	.free_iso_context	= ohci_free_iso_context,
3570 	.set_iso_channels	= ohci_set_iso_channels,
3571 	.queue_iso		= ohci_queue_iso,
3572 	.flush_queue_iso	= ohci_flush_queue_iso,
3573 	.flush_iso_completions	= ohci_flush_iso_completions,
3574 	.start_iso		= ohci_start_iso,
3575 	.stop_iso		= ohci_stop_iso,
3576 };
3577 
3578 #ifdef CONFIG_PPC_PMAC
3579 static void pmac_ohci_on(struct pci_dev *dev)
3580 {
3581 	if (machine_is(powermac)) {
3582 		struct device_node *ofn = pci_device_to_OF_node(dev);
3583 
3584 		if (ofn) {
3585 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3586 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3587 		}
3588 	}
3589 }
3590 
3591 static void pmac_ohci_off(struct pci_dev *dev)
3592 {
3593 	if (machine_is(powermac)) {
3594 		struct device_node *ofn = pci_device_to_OF_node(dev);
3595 
3596 		if (ofn) {
3597 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3598 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3599 		}
3600 	}
3601 }
3602 #else
3603 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3604 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3605 #endif /* CONFIG_PPC_PMAC */
3606 
3607 static void release_ohci(struct device *dev, void *data)
3608 {
3609 	struct pci_dev *pdev = to_pci_dev(dev);
3610 	struct fw_ohci *ohci = pci_get_drvdata(pdev);
3611 
3612 	pmac_ohci_off(pdev);
3613 
3614 	ar_context_release(&ohci->ar_response_ctx);
3615 	ar_context_release(&ohci->ar_request_ctx);
3616 
3617 	dev_notice(dev, "removed fw-ohci device\n");
3618 }
3619 
3620 static int pci_probe(struct pci_dev *dev,
3621 			       const struct pci_device_id *ent)
3622 {
3623 	struct fw_ohci *ohci;
3624 	u32 bus_options, max_receive, link_speed, version;
3625 	u64 guid;
3626 	int i, err;
3627 	size_t size;
3628 
3629 	if (dev->vendor == PCI_VENDOR_ID_PINNACLE_SYSTEMS) {
3630 		dev_err(&dev->dev, "Pinnacle MovieBoard is not yet supported\n");
3631 		return -ENOSYS;
3632 	}
3633 
3634 	ohci = devres_alloc(release_ohci, sizeof(*ohci), GFP_KERNEL);
3635 	if (ohci == NULL)
3636 		return -ENOMEM;
3637 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3638 	pci_set_drvdata(dev, ohci);
3639 	pmac_ohci_on(dev);
3640 	devres_add(&dev->dev, ohci);
3641 
3642 	err = pcim_enable_device(dev);
3643 	if (err) {
3644 		dev_err(&dev->dev, "failed to enable OHCI hardware\n");
3645 		return err;
3646 	}
3647 
3648 	pci_set_master(dev);
3649 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3650 
3651 	spin_lock_init(&ohci->lock);
3652 	mutex_init(&ohci->phy_reg_mutex);
3653 
3654 	INIT_WORK(&ohci->bus_reset_work, bus_reset_work);
3655 
3656 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM) ||
3657 	    pci_resource_len(dev, 0) < OHCI1394_REGISTER_SIZE) {
3658 		ohci_err(ohci, "invalid MMIO resource\n");
3659 		return -ENXIO;
3660 	}
3661 
3662 	err = pcim_iomap_regions(dev, 1 << 0, ohci_driver_name);
3663 	if (err) {
3664 		ohci_err(ohci, "request and map MMIO resource unavailable\n");
3665 		return -ENXIO;
3666 	}
3667 	ohci->registers = pcim_iomap_table(dev)[0];
3668 
3669 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3670 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3671 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3672 		     ohci_quirks[i].device == dev->device) &&
3673 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3674 		     ohci_quirks[i].revision >= dev->revision)) {
3675 			ohci->quirks = ohci_quirks[i].flags;
3676 			break;
3677 		}
3678 	if (param_quirks)
3679 		ohci->quirks = param_quirks;
3680 
3681 	if (detect_vt630x_with_asm1083_on_amd_ryzen_machine(dev))
3682 		ohci->quirks |= QUIRK_REBOOT_BY_CYCLE_TIMER_READ;
3683 
3684 	/*
3685 	 * Because dma_alloc_coherent() allocates at least one page,
3686 	 * we save space by using a common buffer for the AR request/
3687 	 * response descriptors and the self IDs buffer.
3688 	 */
3689 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3690 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3691 	ohci->misc_buffer = dmam_alloc_coherent(&dev->dev, PAGE_SIZE, &ohci->misc_buffer_bus,
3692 						GFP_KERNEL);
3693 	if (!ohci->misc_buffer)
3694 		return -ENOMEM;
3695 
3696 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3697 			      OHCI1394_AsReqRcvContextControlSet);
3698 	if (err < 0)
3699 		return err;
3700 
3701 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3702 			      OHCI1394_AsRspRcvContextControlSet);
3703 	if (err < 0)
3704 		return err;
3705 
3706 	err = context_init(&ohci->at_request_ctx, ohci,
3707 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3708 	if (err < 0)
3709 		return err;
3710 
3711 	err = context_init(&ohci->at_response_ctx, ohci,
3712 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3713 	if (err < 0)
3714 		return err;
3715 
3716 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3717 	ohci->ir_context_channels = ~0ULL;
3718 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3719 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3720 	ohci->ir_context_mask = ohci->ir_context_support;
3721 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3722 	size = sizeof(struct iso_context) * ohci->n_ir;
3723 	ohci->ir_context_list = devm_kzalloc(&dev->dev, size, GFP_KERNEL);
3724 	if (!ohci->ir_context_list)
3725 		return -ENOMEM;
3726 
3727 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3728 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3729 	/* JMicron JMB38x often shows 0 at first read, just ignore it */
3730 	if (!ohci->it_context_support) {
3731 		ohci_notice(ohci, "overriding IsoXmitIntMask\n");
3732 		ohci->it_context_support = 0xf;
3733 	}
3734 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3735 	ohci->it_context_mask = ohci->it_context_support;
3736 	ohci->n_it = hweight32(ohci->it_context_mask);
3737 	size = sizeof(struct iso_context) * ohci->n_it;
3738 	ohci->it_context_list = devm_kzalloc(&dev->dev, size, GFP_KERNEL);
3739 	if (!ohci->it_context_list)
3740 		return -ENOMEM;
3741 
3742 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
3743 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3744 
3745 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3746 	max_receive = (bus_options >> 12) & 0xf;
3747 	link_speed = bus_options & 0x7;
3748 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3749 		reg_read(ohci, OHCI1394_GUIDLo);
3750 
3751 	if (!(ohci->quirks & QUIRK_NO_MSI))
3752 		pci_enable_msi(dev);
3753 	err = devm_request_irq(&dev->dev, dev->irq, irq_handler,
3754 			       pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED, ohci_driver_name, ohci);
3755 	if (err < 0) {
3756 		ohci_err(ohci, "failed to allocate interrupt %d\n", dev->irq);
3757 		goto fail_msi;
3758 	}
3759 
3760 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3761 	if (err)
3762 		goto fail_msi;
3763 
3764 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3765 	ohci_notice(ohci,
3766 		    "added OHCI v%x.%x device as card %d, "
3767 		    "%d IR + %d IT contexts, quirks 0x%x%s\n",
3768 		    version >> 16, version & 0xff, ohci->card.index,
3769 		    ohci->n_ir, ohci->n_it, ohci->quirks,
3770 		    reg_read(ohci, OHCI1394_PhyUpperBound) ?
3771 			", physUB" : "");
3772 
3773 	return 0;
3774 
3775  fail_msi:
3776 	pci_disable_msi(dev);
3777 
3778 	return err;
3779 }
3780 
3781 static void pci_remove(struct pci_dev *dev)
3782 {
3783 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3784 
3785 	/*
3786 	 * If the removal is happening from the suspend state, LPS won't be
3787 	 * enabled and host registers (eg., IntMaskClear) won't be accessible.
3788 	 */
3789 	if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) {
3790 		reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3791 		flush_writes(ohci);
3792 	}
3793 	cancel_work_sync(&ohci->bus_reset_work);
3794 	fw_core_remove_card(&ohci->card);
3795 
3796 	/*
3797 	 * FIXME: Fail all pending packets here, now that the upper
3798 	 * layers can't queue any more.
3799 	 */
3800 
3801 	software_reset(ohci);
3802 
3803 	pci_disable_msi(dev);
3804 
3805 	dev_notice(&dev->dev, "removing fw-ohci device\n");
3806 }
3807 
3808 #ifdef CONFIG_PM
3809 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3810 {
3811 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3812 	int err;
3813 
3814 	software_reset(ohci);
3815 	err = pci_save_state(dev);
3816 	if (err) {
3817 		ohci_err(ohci, "pci_save_state failed\n");
3818 		return err;
3819 	}
3820 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3821 	if (err)
3822 		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
3823 	pmac_ohci_off(dev);
3824 
3825 	return 0;
3826 }
3827 
3828 static int pci_resume(struct pci_dev *dev)
3829 {
3830 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3831 	int err;
3832 
3833 	pmac_ohci_on(dev);
3834 	pci_set_power_state(dev, PCI_D0);
3835 	pci_restore_state(dev);
3836 	err = pci_enable_device(dev);
3837 	if (err) {
3838 		ohci_err(ohci, "pci_enable_device failed\n");
3839 		return err;
3840 	}
3841 
3842 	/* Some systems don't setup GUID register on resume from ram  */
3843 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3844 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3845 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3846 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3847 	}
3848 
3849 	err = ohci_enable(&ohci->card, NULL, 0);
3850 	if (err)
3851 		return err;
3852 
3853 	ohci_resume_iso_dma(ohci);
3854 
3855 	return 0;
3856 }
3857 #endif
3858 
3859 static const struct pci_device_id pci_table[] = {
3860 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3861 	{ }
3862 };
3863 
3864 MODULE_DEVICE_TABLE(pci, pci_table);
3865 
3866 static struct pci_driver fw_ohci_pci_driver = {
3867 	.name		= ohci_driver_name,
3868 	.id_table	= pci_table,
3869 	.probe		= pci_probe,
3870 	.remove		= pci_remove,
3871 #ifdef CONFIG_PM
3872 	.resume		= pci_resume,
3873 	.suspend	= pci_suspend,
3874 #endif
3875 };
3876 
3877 static int __init fw_ohci_init(void)
3878 {
3879 	selfid_workqueue = alloc_workqueue(KBUILD_MODNAME, WQ_MEM_RECLAIM, 0);
3880 	if (!selfid_workqueue)
3881 		return -ENOMEM;
3882 
3883 	return pci_register_driver(&fw_ohci_pci_driver);
3884 }
3885 
3886 static void __exit fw_ohci_cleanup(void)
3887 {
3888 	pci_unregister_driver(&fw_ohci_pci_driver);
3889 	destroy_workqueue(selfid_workqueue);
3890 }
3891 
3892 module_init(fw_ohci_init);
3893 module_exit(fw_ohci_cleanup);
3894 
3895 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3896 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3897 MODULE_LICENSE("GPL");
3898 
3899 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3900 MODULE_ALIAS("ohci1394");
3901