xref: /linux/drivers/firewire/ohci.c (revision f3539c12d8196ce0a1993364d30b3a18908470d1)
1 /*
2  * Driver for OHCI 1394 controllers
3  *
4  * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 #include <linux/bitops.h>
22 #include <linux/bug.h>
23 #include <linux/compiler.h>
24 #include <linux/delay.h>
25 #include <linux/device.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/firewire.h>
28 #include <linux/firewire-constants.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/io.h>
32 #include <linux/kernel.h>
33 #include <linux/list.h>
34 #include <linux/mm.h>
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/mutex.h>
38 #include <linux/pci.h>
39 #include <linux/pci_ids.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/string.h>
43 #include <linux/time.h>
44 #include <linux/vmalloc.h>
45 #include <linux/workqueue.h>
46 
47 #include <asm/byteorder.h>
48 #include <asm/page.h>
49 
50 #ifdef CONFIG_PPC_PMAC
51 #include <asm/pmac_feature.h>
52 #endif
53 
54 #include "core.h"
55 #include "ohci.h"
56 
57 #define ohci_info(ohci, f, args...)	dev_info(ohci->card.device, f, ##args)
58 #define ohci_notice(ohci, f, args...)	dev_notice(ohci->card.device, f, ##args)
59 #define ohci_err(ohci, f, args...)	dev_err(ohci->card.device, f, ##args)
60 
61 #define DESCRIPTOR_OUTPUT_MORE		0
62 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
63 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
64 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
65 #define DESCRIPTOR_STATUS		(1 << 11)
66 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
67 #define DESCRIPTOR_PING			(1 << 7)
68 #define DESCRIPTOR_YY			(1 << 6)
69 #define DESCRIPTOR_NO_IRQ		(0 << 4)
70 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
71 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
72 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
73 #define DESCRIPTOR_WAIT			(3 << 0)
74 
75 #define DESCRIPTOR_CMD			(0xf << 12)
76 
77 struct descriptor {
78 	__le16 req_count;
79 	__le16 control;
80 	__le32 data_address;
81 	__le32 branch_address;
82 	__le16 res_count;
83 	__le16 transfer_status;
84 } __attribute__((aligned(16)));
85 
86 #define CONTROL_SET(regs)	(regs)
87 #define CONTROL_CLEAR(regs)	((regs) + 4)
88 #define COMMAND_PTR(regs)	((regs) + 12)
89 #define CONTEXT_MATCH(regs)	((regs) + 16)
90 
91 #define AR_BUFFER_SIZE	(32*1024)
92 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
93 /* we need at least two pages for proper list management */
94 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
95 
96 #define MAX_ASYNC_PAYLOAD	4096
97 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
98 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
99 
100 struct ar_context {
101 	struct fw_ohci *ohci;
102 	struct page *pages[AR_BUFFERS];
103 	void *buffer;
104 	struct descriptor *descriptors;
105 	dma_addr_t descriptors_bus;
106 	void *pointer;
107 	unsigned int last_buffer_index;
108 	u32 regs;
109 	struct tasklet_struct tasklet;
110 };
111 
112 struct context;
113 
114 typedef int (*descriptor_callback_t)(struct context *ctx,
115 				     struct descriptor *d,
116 				     struct descriptor *last);
117 
118 /*
119  * A buffer that contains a block of DMA-able coherent memory used for
120  * storing a portion of a DMA descriptor program.
121  */
122 struct descriptor_buffer {
123 	struct list_head list;
124 	dma_addr_t buffer_bus;
125 	size_t buffer_size;
126 	size_t used;
127 	struct descriptor buffer[0];
128 };
129 
130 struct context {
131 	struct fw_ohci *ohci;
132 	u32 regs;
133 	int total_allocation;
134 	u32 current_bus;
135 	bool running;
136 	bool flushing;
137 
138 	/*
139 	 * List of page-sized buffers for storing DMA descriptors.
140 	 * Head of list contains buffers in use and tail of list contains
141 	 * free buffers.
142 	 */
143 	struct list_head buffer_list;
144 
145 	/*
146 	 * Pointer to a buffer inside buffer_list that contains the tail
147 	 * end of the current DMA program.
148 	 */
149 	struct descriptor_buffer *buffer_tail;
150 
151 	/*
152 	 * The descriptor containing the branch address of the first
153 	 * descriptor that has not yet been filled by the device.
154 	 */
155 	struct descriptor *last;
156 
157 	/*
158 	 * The last descriptor block in the DMA program. It contains the branch
159 	 * address that must be updated upon appending a new descriptor.
160 	 */
161 	struct descriptor *prev;
162 	int prev_z;
163 
164 	descriptor_callback_t callback;
165 
166 	struct tasklet_struct tasklet;
167 };
168 
169 #define IT_HEADER_SY(v)          ((v) <<  0)
170 #define IT_HEADER_TCODE(v)       ((v) <<  4)
171 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
172 #define IT_HEADER_TAG(v)         ((v) << 14)
173 #define IT_HEADER_SPEED(v)       ((v) << 16)
174 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
175 
176 struct iso_context {
177 	struct fw_iso_context base;
178 	struct context context;
179 	void *header;
180 	size_t header_length;
181 	unsigned long flushing_completions;
182 	u32 mc_buffer_bus;
183 	u16 mc_completed;
184 	u16 last_timestamp;
185 	u8 sync;
186 	u8 tags;
187 };
188 
189 #define CONFIG_ROM_SIZE 1024
190 
191 struct fw_ohci {
192 	struct fw_card card;
193 
194 	__iomem char *registers;
195 	int node_id;
196 	int generation;
197 	int request_generation;	/* for timestamping incoming requests */
198 	unsigned quirks;
199 	unsigned int pri_req_max;
200 	u32 bus_time;
201 	bool bus_time_running;
202 	bool is_root;
203 	bool csr_state_setclear_abdicate;
204 	int n_ir;
205 	int n_it;
206 	/*
207 	 * Spinlock for accessing fw_ohci data.  Never call out of
208 	 * this driver with this lock held.
209 	 */
210 	spinlock_t lock;
211 
212 	struct mutex phy_reg_mutex;
213 
214 	void *misc_buffer;
215 	dma_addr_t misc_buffer_bus;
216 
217 	struct ar_context ar_request_ctx;
218 	struct ar_context ar_response_ctx;
219 	struct context at_request_ctx;
220 	struct context at_response_ctx;
221 
222 	u32 it_context_support;
223 	u32 it_context_mask;     /* unoccupied IT contexts */
224 	struct iso_context *it_context_list;
225 	u64 ir_context_channels; /* unoccupied channels */
226 	u32 ir_context_support;
227 	u32 ir_context_mask;     /* unoccupied IR contexts */
228 	struct iso_context *ir_context_list;
229 	u64 mc_channels; /* channels in use by the multichannel IR context */
230 	bool mc_allocated;
231 
232 	__be32    *config_rom;
233 	dma_addr_t config_rom_bus;
234 	__be32    *next_config_rom;
235 	dma_addr_t next_config_rom_bus;
236 	__be32     next_header;
237 
238 	__le32    *self_id;
239 	dma_addr_t self_id_bus;
240 	struct work_struct bus_reset_work;
241 
242 	u32 self_id_buffer[512];
243 };
244 
245 static struct workqueue_struct *selfid_workqueue;
246 
247 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
248 {
249 	return container_of(card, struct fw_ohci, card);
250 }
251 
252 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
253 #define IR_CONTEXT_BUFFER_FILL		0x80000000
254 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
255 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
256 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
257 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
258 
259 #define CONTEXT_RUN	0x8000
260 #define CONTEXT_WAKE	0x1000
261 #define CONTEXT_DEAD	0x0800
262 #define CONTEXT_ACTIVE	0x0400
263 
264 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
265 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
266 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
267 
268 #define OHCI1394_REGISTER_SIZE		0x800
269 #define OHCI1394_PCI_HCI_Control	0x40
270 #define SELF_ID_BUF_SIZE		0x800
271 #define OHCI_TCODE_PHY_PACKET		0x0e
272 #define OHCI_VERSION_1_1		0x010010
273 
274 static char ohci_driver_name[] = KBUILD_MODNAME;
275 
276 #define PCI_VENDOR_ID_PINNACLE_SYSTEMS	0x11bd
277 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
278 #define PCI_DEVICE_ID_CREATIVE_SB1394	0x4001
279 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
280 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
281 #define PCI_DEVICE_ID_TI_TSB12LV26	0x8020
282 #define PCI_DEVICE_ID_TI_TSB82AA2	0x8025
283 #define PCI_DEVICE_ID_VIA_VT630X	0x3044
284 #define PCI_REV_ID_VIA_VT6306		0x46
285 #define PCI_DEVICE_ID_VIA_VT6315	0x3403
286 
287 #define QUIRK_CYCLE_TIMER		0x1
288 #define QUIRK_RESET_PACKET		0x2
289 #define QUIRK_BE_HEADERS		0x4
290 #define QUIRK_NO_1394A			0x8
291 #define QUIRK_NO_MSI			0x10
292 #define QUIRK_TI_SLLZ059		0x20
293 #define QUIRK_IR_WAKE			0x40
294 
295 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
296 static const struct {
297 	unsigned short vendor, device, revision, flags;
298 } ohci_quirks[] = {
299 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
300 		QUIRK_CYCLE_TIMER},
301 
302 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
303 		QUIRK_BE_HEADERS},
304 
305 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
306 		QUIRK_NO_MSI},
307 
308 	{PCI_VENDOR_ID_CREATIVE, PCI_DEVICE_ID_CREATIVE_SB1394, PCI_ANY_ID,
309 		QUIRK_RESET_PACKET},
310 
311 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
312 		QUIRK_NO_MSI},
313 
314 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
315 		QUIRK_CYCLE_TIMER},
316 
317 	{PCI_VENDOR_ID_O2, PCI_ANY_ID, PCI_ANY_ID,
318 		QUIRK_NO_MSI},
319 
320 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
321 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
322 
323 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
324 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
325 
326 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV26, PCI_ANY_ID,
327 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
328 
329 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB82AA2, PCI_ANY_ID,
330 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
331 
332 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
333 		QUIRK_RESET_PACKET},
334 
335 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT630X, PCI_REV_ID_VIA_VT6306,
336 		QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE},
337 
338 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, 0,
339 		QUIRK_CYCLE_TIMER /* FIXME: necessary? */ | QUIRK_NO_MSI},
340 
341 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, PCI_ANY_ID,
342 		QUIRK_NO_MSI},
343 
344 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
345 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
346 };
347 
348 /* This overrides anything that was found in ohci_quirks[]. */
349 static int param_quirks;
350 module_param_named(quirks, param_quirks, int, 0644);
351 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
352 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
353 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
354 	", AR/selfID endianness = "	__stringify(QUIRK_BE_HEADERS)
355 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
356 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
357 	", TI SLLZ059 erratum = "	__stringify(QUIRK_TI_SLLZ059)
358 	", IR wake unreliable = "	__stringify(QUIRK_IR_WAKE)
359 	")");
360 
361 #define OHCI_PARAM_DEBUG_AT_AR		1
362 #define OHCI_PARAM_DEBUG_SELFIDS	2
363 #define OHCI_PARAM_DEBUG_IRQS		4
364 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
365 
366 static int param_debug;
367 module_param_named(debug, param_debug, int, 0644);
368 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
369 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
370 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
371 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
372 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
373 	", or a combination, or all = -1)");
374 
375 static bool param_remote_dma;
376 module_param_named(remote_dma, param_remote_dma, bool, 0444);
377 MODULE_PARM_DESC(remote_dma, "Enable unfiltered remote DMA (default = N)");
378 
379 static void log_irqs(struct fw_ohci *ohci, u32 evt)
380 {
381 	if (likely(!(param_debug &
382 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
383 		return;
384 
385 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
386 	    !(evt & OHCI1394_busReset))
387 		return;
388 
389 	ohci_notice(ohci, "IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
390 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
391 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
392 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
393 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
394 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
395 	    evt & OHCI1394_isochRx		? " IR"			: "",
396 	    evt & OHCI1394_isochTx		? " IT"			: "",
397 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
398 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
399 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
400 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
401 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
402 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
403 	    evt & OHCI1394_busReset		? " busReset"		: "",
404 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
405 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
406 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
407 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
408 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
409 		    OHCI1394_cycleInconsistent |
410 		    OHCI1394_regAccessFail | OHCI1394_busReset)
411 						? " ?"			: "");
412 }
413 
414 static const char *speed[] = {
415 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
416 };
417 static const char *power[] = {
418 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
419 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
420 };
421 static const char port[] = { '.', '-', 'p', 'c', };
422 
423 static char _p(u32 *s, int shift)
424 {
425 	return port[*s >> shift & 3];
426 }
427 
428 static void log_selfids(struct fw_ohci *ohci, int generation, int self_id_count)
429 {
430 	u32 *s;
431 
432 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
433 		return;
434 
435 	ohci_notice(ohci, "%d selfIDs, generation %d, local node ID %04x\n",
436 		    self_id_count, generation, ohci->node_id);
437 
438 	for (s = ohci->self_id_buffer; self_id_count--; ++s)
439 		if ((*s & 1 << 23) == 0)
440 			ohci_notice(ohci,
441 			    "selfID 0: %08x, phy %d [%c%c%c] %s gc=%d %s %s%s%s\n",
442 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
443 			    speed[*s >> 14 & 3], *s >> 16 & 63,
444 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
445 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
446 		else
447 			ohci_notice(ohci,
448 			    "selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
449 			    *s, *s >> 24 & 63,
450 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
451 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
452 }
453 
454 static const char *evts[] = {
455 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
456 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
457 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
458 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
459 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
460 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
461 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
462 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
463 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
464 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
465 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
466 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
467 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
468 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
469 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
470 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
471 	[0x20] = "pending/cancelled",
472 };
473 static const char *tcodes[] = {
474 	[0x0] = "QW req",		[0x1] = "BW req",
475 	[0x2] = "W resp",		[0x3] = "-reserved-",
476 	[0x4] = "QR req",		[0x5] = "BR req",
477 	[0x6] = "QR resp",		[0x7] = "BR resp",
478 	[0x8] = "cycle start",		[0x9] = "Lk req",
479 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
480 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
481 	[0xe] = "link internal",	[0xf] = "-reserved-",
482 };
483 
484 static void log_ar_at_event(struct fw_ohci *ohci,
485 			    char dir, int speed, u32 *header, int evt)
486 {
487 	int tcode = header[0] >> 4 & 0xf;
488 	char specific[12];
489 
490 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
491 		return;
492 
493 	if (unlikely(evt >= ARRAY_SIZE(evts)))
494 			evt = 0x1f;
495 
496 	if (evt == OHCI1394_evt_bus_reset) {
497 		ohci_notice(ohci, "A%c evt_bus_reset, generation %d\n",
498 			    dir, (header[2] >> 16) & 0xff);
499 		return;
500 	}
501 
502 	switch (tcode) {
503 	case 0x0: case 0x6: case 0x8:
504 		snprintf(specific, sizeof(specific), " = %08x",
505 			 be32_to_cpu((__force __be32)header[3]));
506 		break;
507 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
508 		snprintf(specific, sizeof(specific), " %x,%x",
509 			 header[3] >> 16, header[3] & 0xffff);
510 		break;
511 	default:
512 		specific[0] = '\0';
513 	}
514 
515 	switch (tcode) {
516 	case 0xa:
517 		ohci_notice(ohci, "A%c %s, %s\n",
518 			    dir, evts[evt], tcodes[tcode]);
519 		break;
520 	case 0xe:
521 		ohci_notice(ohci, "A%c %s, PHY %08x %08x\n",
522 			    dir, evts[evt], header[1], header[2]);
523 		break;
524 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
525 		ohci_notice(ohci,
526 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s, %04x%08x%s\n",
527 			    dir, speed, header[0] >> 10 & 0x3f,
528 			    header[1] >> 16, header[0] >> 16, evts[evt],
529 			    tcodes[tcode], header[1] & 0xffff, header[2], specific);
530 		break;
531 	default:
532 		ohci_notice(ohci,
533 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s%s\n",
534 			    dir, speed, header[0] >> 10 & 0x3f,
535 			    header[1] >> 16, header[0] >> 16, evts[evt],
536 			    tcodes[tcode], specific);
537 	}
538 }
539 
540 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
541 {
542 	writel(data, ohci->registers + offset);
543 }
544 
545 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
546 {
547 	return readl(ohci->registers + offset);
548 }
549 
550 static inline void flush_writes(const struct fw_ohci *ohci)
551 {
552 	/* Do a dummy read to flush writes. */
553 	reg_read(ohci, OHCI1394_Version);
554 }
555 
556 /*
557  * Beware!  read_phy_reg(), write_phy_reg(), update_phy_reg(), and
558  * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
559  * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
560  * directly.  Exceptions are intrinsically serialized contexts like pci_probe.
561  */
562 static int read_phy_reg(struct fw_ohci *ohci, int addr)
563 {
564 	u32 val;
565 	int i;
566 
567 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
568 	for (i = 0; i < 3 + 100; i++) {
569 		val = reg_read(ohci, OHCI1394_PhyControl);
570 		if (!~val)
571 			return -ENODEV; /* Card was ejected. */
572 
573 		if (val & OHCI1394_PhyControl_ReadDone)
574 			return OHCI1394_PhyControl_ReadData(val);
575 
576 		/*
577 		 * Try a few times without waiting.  Sleeping is necessary
578 		 * only when the link/PHY interface is busy.
579 		 */
580 		if (i >= 3)
581 			msleep(1);
582 	}
583 	ohci_err(ohci, "failed to read phy reg %d\n", addr);
584 	dump_stack();
585 
586 	return -EBUSY;
587 }
588 
589 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
590 {
591 	int i;
592 
593 	reg_write(ohci, OHCI1394_PhyControl,
594 		  OHCI1394_PhyControl_Write(addr, val));
595 	for (i = 0; i < 3 + 100; i++) {
596 		val = reg_read(ohci, OHCI1394_PhyControl);
597 		if (!~val)
598 			return -ENODEV; /* Card was ejected. */
599 
600 		if (!(val & OHCI1394_PhyControl_WritePending))
601 			return 0;
602 
603 		if (i >= 3)
604 			msleep(1);
605 	}
606 	ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
607 	dump_stack();
608 
609 	return -EBUSY;
610 }
611 
612 static int update_phy_reg(struct fw_ohci *ohci, int addr,
613 			  int clear_bits, int set_bits)
614 {
615 	int ret = read_phy_reg(ohci, addr);
616 	if (ret < 0)
617 		return ret;
618 
619 	/*
620 	 * The interrupt status bits are cleared by writing a one bit.
621 	 * Avoid clearing them unless explicitly requested in set_bits.
622 	 */
623 	if (addr == 5)
624 		clear_bits |= PHY_INT_STATUS_BITS;
625 
626 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
627 }
628 
629 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
630 {
631 	int ret;
632 
633 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
634 	if (ret < 0)
635 		return ret;
636 
637 	return read_phy_reg(ohci, addr);
638 }
639 
640 static int ohci_read_phy_reg(struct fw_card *card, int addr)
641 {
642 	struct fw_ohci *ohci = fw_ohci(card);
643 	int ret;
644 
645 	mutex_lock(&ohci->phy_reg_mutex);
646 	ret = read_phy_reg(ohci, addr);
647 	mutex_unlock(&ohci->phy_reg_mutex);
648 
649 	return ret;
650 }
651 
652 static int ohci_update_phy_reg(struct fw_card *card, int addr,
653 			       int clear_bits, int set_bits)
654 {
655 	struct fw_ohci *ohci = fw_ohci(card);
656 	int ret;
657 
658 	mutex_lock(&ohci->phy_reg_mutex);
659 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
660 	mutex_unlock(&ohci->phy_reg_mutex);
661 
662 	return ret;
663 }
664 
665 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
666 {
667 	return page_private(ctx->pages[i]);
668 }
669 
670 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
671 {
672 	struct descriptor *d;
673 
674 	d = &ctx->descriptors[index];
675 	d->branch_address  &= cpu_to_le32(~0xf);
676 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
677 	d->transfer_status =  0;
678 
679 	wmb(); /* finish init of new descriptors before branch_address update */
680 	d = &ctx->descriptors[ctx->last_buffer_index];
681 	d->branch_address  |= cpu_to_le32(1);
682 
683 	ctx->last_buffer_index = index;
684 
685 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
686 }
687 
688 static void ar_context_release(struct ar_context *ctx)
689 {
690 	unsigned int i;
691 
692 	vunmap(ctx->buffer);
693 
694 	for (i = 0; i < AR_BUFFERS; i++)
695 		if (ctx->pages[i]) {
696 			dma_unmap_page(ctx->ohci->card.device,
697 				       ar_buffer_bus(ctx, i),
698 				       PAGE_SIZE, DMA_FROM_DEVICE);
699 			__free_page(ctx->pages[i]);
700 		}
701 }
702 
703 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
704 {
705 	struct fw_ohci *ohci = ctx->ohci;
706 
707 	if (reg_read(ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
708 		reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
709 		flush_writes(ohci);
710 
711 		ohci_err(ohci, "AR error: %s; DMA stopped\n", error_msg);
712 	}
713 	/* FIXME: restart? */
714 }
715 
716 static inline unsigned int ar_next_buffer_index(unsigned int index)
717 {
718 	return (index + 1) % AR_BUFFERS;
719 }
720 
721 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
722 {
723 	return ar_next_buffer_index(ctx->last_buffer_index);
724 }
725 
726 /*
727  * We search for the buffer that contains the last AR packet DMA data written
728  * by the controller.
729  */
730 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
731 						 unsigned int *buffer_offset)
732 {
733 	unsigned int i, next_i, last = ctx->last_buffer_index;
734 	__le16 res_count, next_res_count;
735 
736 	i = ar_first_buffer_index(ctx);
737 	res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
738 
739 	/* A buffer that is not yet completely filled must be the last one. */
740 	while (i != last && res_count == 0) {
741 
742 		/* Peek at the next descriptor. */
743 		next_i = ar_next_buffer_index(i);
744 		rmb(); /* read descriptors in order */
745 		next_res_count = ACCESS_ONCE(
746 				ctx->descriptors[next_i].res_count);
747 		/*
748 		 * If the next descriptor is still empty, we must stop at this
749 		 * descriptor.
750 		 */
751 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
752 			/*
753 			 * The exception is when the DMA data for one packet is
754 			 * split over three buffers; in this case, the middle
755 			 * buffer's descriptor might be never updated by the
756 			 * controller and look still empty, and we have to peek
757 			 * at the third one.
758 			 */
759 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
760 				next_i = ar_next_buffer_index(next_i);
761 				rmb();
762 				next_res_count = ACCESS_ONCE(
763 					ctx->descriptors[next_i].res_count);
764 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
765 					goto next_buffer_is_active;
766 			}
767 
768 			break;
769 		}
770 
771 next_buffer_is_active:
772 		i = next_i;
773 		res_count = next_res_count;
774 	}
775 
776 	rmb(); /* read res_count before the DMA data */
777 
778 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
779 	if (*buffer_offset > PAGE_SIZE) {
780 		*buffer_offset = 0;
781 		ar_context_abort(ctx, "corrupted descriptor");
782 	}
783 
784 	return i;
785 }
786 
787 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
788 				    unsigned int end_buffer_index,
789 				    unsigned int end_buffer_offset)
790 {
791 	unsigned int i;
792 
793 	i = ar_first_buffer_index(ctx);
794 	while (i != end_buffer_index) {
795 		dma_sync_single_for_cpu(ctx->ohci->card.device,
796 					ar_buffer_bus(ctx, i),
797 					PAGE_SIZE, DMA_FROM_DEVICE);
798 		i = ar_next_buffer_index(i);
799 	}
800 	if (end_buffer_offset > 0)
801 		dma_sync_single_for_cpu(ctx->ohci->card.device,
802 					ar_buffer_bus(ctx, i),
803 					end_buffer_offset, DMA_FROM_DEVICE);
804 }
805 
806 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
807 #define cond_le32_to_cpu(v) \
808 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
809 #else
810 #define cond_le32_to_cpu(v) le32_to_cpu(v)
811 #endif
812 
813 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
814 {
815 	struct fw_ohci *ohci = ctx->ohci;
816 	struct fw_packet p;
817 	u32 status, length, tcode;
818 	int evt;
819 
820 	p.header[0] = cond_le32_to_cpu(buffer[0]);
821 	p.header[1] = cond_le32_to_cpu(buffer[1]);
822 	p.header[2] = cond_le32_to_cpu(buffer[2]);
823 
824 	tcode = (p.header[0] >> 4) & 0x0f;
825 	switch (tcode) {
826 	case TCODE_WRITE_QUADLET_REQUEST:
827 	case TCODE_READ_QUADLET_RESPONSE:
828 		p.header[3] = (__force __u32) buffer[3];
829 		p.header_length = 16;
830 		p.payload_length = 0;
831 		break;
832 
833 	case TCODE_READ_BLOCK_REQUEST :
834 		p.header[3] = cond_le32_to_cpu(buffer[3]);
835 		p.header_length = 16;
836 		p.payload_length = 0;
837 		break;
838 
839 	case TCODE_WRITE_BLOCK_REQUEST:
840 	case TCODE_READ_BLOCK_RESPONSE:
841 	case TCODE_LOCK_REQUEST:
842 	case TCODE_LOCK_RESPONSE:
843 		p.header[3] = cond_le32_to_cpu(buffer[3]);
844 		p.header_length = 16;
845 		p.payload_length = p.header[3] >> 16;
846 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
847 			ar_context_abort(ctx, "invalid packet length");
848 			return NULL;
849 		}
850 		break;
851 
852 	case TCODE_WRITE_RESPONSE:
853 	case TCODE_READ_QUADLET_REQUEST:
854 	case OHCI_TCODE_PHY_PACKET:
855 		p.header_length = 12;
856 		p.payload_length = 0;
857 		break;
858 
859 	default:
860 		ar_context_abort(ctx, "invalid tcode");
861 		return NULL;
862 	}
863 
864 	p.payload = (void *) buffer + p.header_length;
865 
866 	/* FIXME: What to do about evt_* errors? */
867 	length = (p.header_length + p.payload_length + 3) / 4;
868 	status = cond_le32_to_cpu(buffer[length]);
869 	evt    = (status >> 16) & 0x1f;
870 
871 	p.ack        = evt - 16;
872 	p.speed      = (status >> 21) & 0x7;
873 	p.timestamp  = status & 0xffff;
874 	p.generation = ohci->request_generation;
875 
876 	log_ar_at_event(ohci, 'R', p.speed, p.header, evt);
877 
878 	/*
879 	 * Several controllers, notably from NEC and VIA, forget to
880 	 * write ack_complete status at PHY packet reception.
881 	 */
882 	if (evt == OHCI1394_evt_no_status &&
883 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
884 		p.ack = ACK_COMPLETE;
885 
886 	/*
887 	 * The OHCI bus reset handler synthesizes a PHY packet with
888 	 * the new generation number when a bus reset happens (see
889 	 * section 8.4.2.3).  This helps us determine when a request
890 	 * was received and make sure we send the response in the same
891 	 * generation.  We only need this for requests; for responses
892 	 * we use the unique tlabel for finding the matching
893 	 * request.
894 	 *
895 	 * Alas some chips sometimes emit bus reset packets with a
896 	 * wrong generation.  We set the correct generation for these
897 	 * at a slightly incorrect time (in bus_reset_work).
898 	 */
899 	if (evt == OHCI1394_evt_bus_reset) {
900 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
901 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
902 	} else if (ctx == &ohci->ar_request_ctx) {
903 		fw_core_handle_request(&ohci->card, &p);
904 	} else {
905 		fw_core_handle_response(&ohci->card, &p);
906 	}
907 
908 	return buffer + length + 1;
909 }
910 
911 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
912 {
913 	void *next;
914 
915 	while (p < end) {
916 		next = handle_ar_packet(ctx, p);
917 		if (!next)
918 			return p;
919 		p = next;
920 	}
921 
922 	return p;
923 }
924 
925 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
926 {
927 	unsigned int i;
928 
929 	i = ar_first_buffer_index(ctx);
930 	while (i != end_buffer) {
931 		dma_sync_single_for_device(ctx->ohci->card.device,
932 					   ar_buffer_bus(ctx, i),
933 					   PAGE_SIZE, DMA_FROM_DEVICE);
934 		ar_context_link_page(ctx, i);
935 		i = ar_next_buffer_index(i);
936 	}
937 }
938 
939 static void ar_context_tasklet(unsigned long data)
940 {
941 	struct ar_context *ctx = (struct ar_context *)data;
942 	unsigned int end_buffer_index, end_buffer_offset;
943 	void *p, *end;
944 
945 	p = ctx->pointer;
946 	if (!p)
947 		return;
948 
949 	end_buffer_index = ar_search_last_active_buffer(ctx,
950 							&end_buffer_offset);
951 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
952 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
953 
954 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
955 		/*
956 		 * The filled part of the overall buffer wraps around; handle
957 		 * all packets up to the buffer end here.  If the last packet
958 		 * wraps around, its tail will be visible after the buffer end
959 		 * because the buffer start pages are mapped there again.
960 		 */
961 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
962 		p = handle_ar_packets(ctx, p, buffer_end);
963 		if (p < buffer_end)
964 			goto error;
965 		/* adjust p to point back into the actual buffer */
966 		p -= AR_BUFFERS * PAGE_SIZE;
967 	}
968 
969 	p = handle_ar_packets(ctx, p, end);
970 	if (p != end) {
971 		if (p > end)
972 			ar_context_abort(ctx, "inconsistent descriptor");
973 		goto error;
974 	}
975 
976 	ctx->pointer = p;
977 	ar_recycle_buffers(ctx, end_buffer_index);
978 
979 	return;
980 
981 error:
982 	ctx->pointer = NULL;
983 }
984 
985 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
986 			   unsigned int descriptors_offset, u32 regs)
987 {
988 	unsigned int i;
989 	dma_addr_t dma_addr;
990 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
991 	struct descriptor *d;
992 
993 	ctx->regs        = regs;
994 	ctx->ohci        = ohci;
995 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
996 
997 	for (i = 0; i < AR_BUFFERS; i++) {
998 		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
999 		if (!ctx->pages[i])
1000 			goto out_of_memory;
1001 		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
1002 					0, PAGE_SIZE, DMA_FROM_DEVICE);
1003 		if (dma_mapping_error(ohci->card.device, dma_addr)) {
1004 			__free_page(ctx->pages[i]);
1005 			ctx->pages[i] = NULL;
1006 			goto out_of_memory;
1007 		}
1008 		set_page_private(ctx->pages[i], dma_addr);
1009 	}
1010 
1011 	for (i = 0; i < AR_BUFFERS; i++)
1012 		pages[i]              = ctx->pages[i];
1013 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
1014 		pages[AR_BUFFERS + i] = ctx->pages[i];
1015 	ctx->buffer = vmap(pages, ARRAY_SIZE(pages), VM_MAP, PAGE_KERNEL);
1016 	if (!ctx->buffer)
1017 		goto out_of_memory;
1018 
1019 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
1020 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
1021 
1022 	for (i = 0; i < AR_BUFFERS; i++) {
1023 		d = &ctx->descriptors[i];
1024 		d->req_count      = cpu_to_le16(PAGE_SIZE);
1025 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
1026 						DESCRIPTOR_STATUS |
1027 						DESCRIPTOR_BRANCH_ALWAYS);
1028 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
1029 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
1030 			ar_next_buffer_index(i) * sizeof(struct descriptor));
1031 	}
1032 
1033 	return 0;
1034 
1035 out_of_memory:
1036 	ar_context_release(ctx);
1037 
1038 	return -ENOMEM;
1039 }
1040 
1041 static void ar_context_run(struct ar_context *ctx)
1042 {
1043 	unsigned int i;
1044 
1045 	for (i = 0; i < AR_BUFFERS; i++)
1046 		ar_context_link_page(ctx, i);
1047 
1048 	ctx->pointer = ctx->buffer;
1049 
1050 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1051 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1052 }
1053 
1054 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1055 {
1056 	__le16 branch;
1057 
1058 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1059 
1060 	/* figure out which descriptor the branch address goes in */
1061 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1062 		return d;
1063 	else
1064 		return d + z - 1;
1065 }
1066 
1067 static void context_tasklet(unsigned long data)
1068 {
1069 	struct context *ctx = (struct context *) data;
1070 	struct descriptor *d, *last;
1071 	u32 address;
1072 	int z;
1073 	struct descriptor_buffer *desc;
1074 
1075 	desc = list_entry(ctx->buffer_list.next,
1076 			struct descriptor_buffer, list);
1077 	last = ctx->last;
1078 	while (last->branch_address != 0) {
1079 		struct descriptor_buffer *old_desc = desc;
1080 		address = le32_to_cpu(last->branch_address);
1081 		z = address & 0xf;
1082 		address &= ~0xf;
1083 		ctx->current_bus = address;
1084 
1085 		/* If the branch address points to a buffer outside of the
1086 		 * current buffer, advance to the next buffer. */
1087 		if (address < desc->buffer_bus ||
1088 				address >= desc->buffer_bus + desc->used)
1089 			desc = list_entry(desc->list.next,
1090 					struct descriptor_buffer, list);
1091 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1092 		last = find_branch_descriptor(d, z);
1093 
1094 		if (!ctx->callback(ctx, d, last))
1095 			break;
1096 
1097 		if (old_desc != desc) {
1098 			/* If we've advanced to the next buffer, move the
1099 			 * previous buffer to the free list. */
1100 			unsigned long flags;
1101 			old_desc->used = 0;
1102 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1103 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1104 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1105 		}
1106 		ctx->last = last;
1107 	}
1108 }
1109 
1110 /*
1111  * Allocate a new buffer and add it to the list of free buffers for this
1112  * context.  Must be called with ohci->lock held.
1113  */
1114 static int context_add_buffer(struct context *ctx)
1115 {
1116 	struct descriptor_buffer *desc;
1117 	dma_addr_t uninitialized_var(bus_addr);
1118 	int offset;
1119 
1120 	/*
1121 	 * 16MB of descriptors should be far more than enough for any DMA
1122 	 * program.  This will catch run-away userspace or DoS attacks.
1123 	 */
1124 	if (ctx->total_allocation >= 16*1024*1024)
1125 		return -ENOMEM;
1126 
1127 	desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1128 			&bus_addr, GFP_ATOMIC);
1129 	if (!desc)
1130 		return -ENOMEM;
1131 
1132 	offset = (void *)&desc->buffer - (void *)desc;
1133 	desc->buffer_size = PAGE_SIZE - offset;
1134 	desc->buffer_bus = bus_addr + offset;
1135 	desc->used = 0;
1136 
1137 	list_add_tail(&desc->list, &ctx->buffer_list);
1138 	ctx->total_allocation += PAGE_SIZE;
1139 
1140 	return 0;
1141 }
1142 
1143 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1144 			u32 regs, descriptor_callback_t callback)
1145 {
1146 	ctx->ohci = ohci;
1147 	ctx->regs = regs;
1148 	ctx->total_allocation = 0;
1149 
1150 	INIT_LIST_HEAD(&ctx->buffer_list);
1151 	if (context_add_buffer(ctx) < 0)
1152 		return -ENOMEM;
1153 
1154 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1155 			struct descriptor_buffer, list);
1156 
1157 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1158 	ctx->callback = callback;
1159 
1160 	/*
1161 	 * We put a dummy descriptor in the buffer that has a NULL
1162 	 * branch address and looks like it's been sent.  That way we
1163 	 * have a descriptor to append DMA programs to.
1164 	 */
1165 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1166 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1167 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1168 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1169 	ctx->last = ctx->buffer_tail->buffer;
1170 	ctx->prev = ctx->buffer_tail->buffer;
1171 	ctx->prev_z = 1;
1172 
1173 	return 0;
1174 }
1175 
1176 static void context_release(struct context *ctx)
1177 {
1178 	struct fw_card *card = &ctx->ohci->card;
1179 	struct descriptor_buffer *desc, *tmp;
1180 
1181 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1182 		dma_free_coherent(card->device, PAGE_SIZE, desc,
1183 			desc->buffer_bus -
1184 			((void *)&desc->buffer - (void *)desc));
1185 }
1186 
1187 /* Must be called with ohci->lock held */
1188 static struct descriptor *context_get_descriptors(struct context *ctx,
1189 						  int z, dma_addr_t *d_bus)
1190 {
1191 	struct descriptor *d = NULL;
1192 	struct descriptor_buffer *desc = ctx->buffer_tail;
1193 
1194 	if (z * sizeof(*d) > desc->buffer_size)
1195 		return NULL;
1196 
1197 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1198 		/* No room for the descriptor in this buffer, so advance to the
1199 		 * next one. */
1200 
1201 		if (desc->list.next == &ctx->buffer_list) {
1202 			/* If there is no free buffer next in the list,
1203 			 * allocate one. */
1204 			if (context_add_buffer(ctx) < 0)
1205 				return NULL;
1206 		}
1207 		desc = list_entry(desc->list.next,
1208 				struct descriptor_buffer, list);
1209 		ctx->buffer_tail = desc;
1210 	}
1211 
1212 	d = desc->buffer + desc->used / sizeof(*d);
1213 	memset(d, 0, z * sizeof(*d));
1214 	*d_bus = desc->buffer_bus + desc->used;
1215 
1216 	return d;
1217 }
1218 
1219 static void context_run(struct context *ctx, u32 extra)
1220 {
1221 	struct fw_ohci *ohci = ctx->ohci;
1222 
1223 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1224 		  le32_to_cpu(ctx->last->branch_address));
1225 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1226 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1227 	ctx->running = true;
1228 	flush_writes(ohci);
1229 }
1230 
1231 static void context_append(struct context *ctx,
1232 			   struct descriptor *d, int z, int extra)
1233 {
1234 	dma_addr_t d_bus;
1235 	struct descriptor_buffer *desc = ctx->buffer_tail;
1236 	struct descriptor *d_branch;
1237 
1238 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1239 
1240 	desc->used += (z + extra) * sizeof(*d);
1241 
1242 	wmb(); /* finish init of new descriptors before branch_address update */
1243 
1244 	d_branch = find_branch_descriptor(ctx->prev, ctx->prev_z);
1245 	d_branch->branch_address = cpu_to_le32(d_bus | z);
1246 
1247 	/*
1248 	 * VT6306 incorrectly checks only the single descriptor at the
1249 	 * CommandPtr when the wake bit is written, so if it's a
1250 	 * multi-descriptor block starting with an INPUT_MORE, put a copy of
1251 	 * the branch address in the first descriptor.
1252 	 *
1253 	 * Not doing this for transmit contexts since not sure how it interacts
1254 	 * with skip addresses.
1255 	 */
1256 	if (unlikely(ctx->ohci->quirks & QUIRK_IR_WAKE) &&
1257 	    d_branch != ctx->prev &&
1258 	    (ctx->prev->control & cpu_to_le16(DESCRIPTOR_CMD)) ==
1259 	     cpu_to_le16(DESCRIPTOR_INPUT_MORE)) {
1260 		ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1261 	}
1262 
1263 	ctx->prev = d;
1264 	ctx->prev_z = z;
1265 }
1266 
1267 static void context_stop(struct context *ctx)
1268 {
1269 	struct fw_ohci *ohci = ctx->ohci;
1270 	u32 reg;
1271 	int i;
1272 
1273 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1274 	ctx->running = false;
1275 
1276 	for (i = 0; i < 1000; i++) {
1277 		reg = reg_read(ohci, CONTROL_SET(ctx->regs));
1278 		if ((reg & CONTEXT_ACTIVE) == 0)
1279 			return;
1280 
1281 		if (i)
1282 			udelay(10);
1283 	}
1284 	ohci_err(ohci, "DMA context still active (0x%08x)\n", reg);
1285 }
1286 
1287 struct driver_data {
1288 	u8 inline_data[8];
1289 	struct fw_packet *packet;
1290 };
1291 
1292 /*
1293  * This function apppends a packet to the DMA queue for transmission.
1294  * Must always be called with the ochi->lock held to ensure proper
1295  * generation handling and locking around packet queue manipulation.
1296  */
1297 static int at_context_queue_packet(struct context *ctx,
1298 				   struct fw_packet *packet)
1299 {
1300 	struct fw_ohci *ohci = ctx->ohci;
1301 	dma_addr_t d_bus, uninitialized_var(payload_bus);
1302 	struct driver_data *driver_data;
1303 	struct descriptor *d, *last;
1304 	__le32 *header;
1305 	int z, tcode;
1306 
1307 	d = context_get_descriptors(ctx, 4, &d_bus);
1308 	if (d == NULL) {
1309 		packet->ack = RCODE_SEND_ERROR;
1310 		return -1;
1311 	}
1312 
1313 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1314 	d[0].res_count = cpu_to_le16(packet->timestamp);
1315 
1316 	/*
1317 	 * The DMA format for asynchronous link packets is different
1318 	 * from the IEEE1394 layout, so shift the fields around
1319 	 * accordingly.
1320 	 */
1321 
1322 	tcode = (packet->header[0] >> 4) & 0x0f;
1323 	header = (__le32 *) &d[1];
1324 	switch (tcode) {
1325 	case TCODE_WRITE_QUADLET_REQUEST:
1326 	case TCODE_WRITE_BLOCK_REQUEST:
1327 	case TCODE_WRITE_RESPONSE:
1328 	case TCODE_READ_QUADLET_REQUEST:
1329 	case TCODE_READ_BLOCK_REQUEST:
1330 	case TCODE_READ_QUADLET_RESPONSE:
1331 	case TCODE_READ_BLOCK_RESPONSE:
1332 	case TCODE_LOCK_REQUEST:
1333 	case TCODE_LOCK_RESPONSE:
1334 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1335 					(packet->speed << 16));
1336 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1337 					(packet->header[0] & 0xffff0000));
1338 		header[2] = cpu_to_le32(packet->header[2]);
1339 
1340 		if (TCODE_IS_BLOCK_PACKET(tcode))
1341 			header[3] = cpu_to_le32(packet->header[3]);
1342 		else
1343 			header[3] = (__force __le32) packet->header[3];
1344 
1345 		d[0].req_count = cpu_to_le16(packet->header_length);
1346 		break;
1347 
1348 	case TCODE_LINK_INTERNAL:
1349 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1350 					(packet->speed << 16));
1351 		header[1] = cpu_to_le32(packet->header[1]);
1352 		header[2] = cpu_to_le32(packet->header[2]);
1353 		d[0].req_count = cpu_to_le16(12);
1354 
1355 		if (is_ping_packet(&packet->header[1]))
1356 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1357 		break;
1358 
1359 	case TCODE_STREAM_DATA:
1360 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1361 					(packet->speed << 16));
1362 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1363 		d[0].req_count = cpu_to_le16(8);
1364 		break;
1365 
1366 	default:
1367 		/* BUG(); */
1368 		packet->ack = RCODE_SEND_ERROR;
1369 		return -1;
1370 	}
1371 
1372 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1373 	driver_data = (struct driver_data *) &d[3];
1374 	driver_data->packet = packet;
1375 	packet->driver_data = driver_data;
1376 
1377 	if (packet->payload_length > 0) {
1378 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1379 			payload_bus = dma_map_single(ohci->card.device,
1380 						     packet->payload,
1381 						     packet->payload_length,
1382 						     DMA_TO_DEVICE);
1383 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1384 				packet->ack = RCODE_SEND_ERROR;
1385 				return -1;
1386 			}
1387 			packet->payload_bus	= payload_bus;
1388 			packet->payload_mapped	= true;
1389 		} else {
1390 			memcpy(driver_data->inline_data, packet->payload,
1391 			       packet->payload_length);
1392 			payload_bus = d_bus + 3 * sizeof(*d);
1393 		}
1394 
1395 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1396 		d[2].data_address = cpu_to_le32(payload_bus);
1397 		last = &d[2];
1398 		z = 3;
1399 	} else {
1400 		last = &d[0];
1401 		z = 2;
1402 	}
1403 
1404 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1405 				     DESCRIPTOR_IRQ_ALWAYS |
1406 				     DESCRIPTOR_BRANCH_ALWAYS);
1407 
1408 	/* FIXME: Document how the locking works. */
1409 	if (ohci->generation != packet->generation) {
1410 		if (packet->payload_mapped)
1411 			dma_unmap_single(ohci->card.device, payload_bus,
1412 					 packet->payload_length, DMA_TO_DEVICE);
1413 		packet->ack = RCODE_GENERATION;
1414 		return -1;
1415 	}
1416 
1417 	context_append(ctx, d, z, 4 - z);
1418 
1419 	if (ctx->running)
1420 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1421 	else
1422 		context_run(ctx, 0);
1423 
1424 	return 0;
1425 }
1426 
1427 static void at_context_flush(struct context *ctx)
1428 {
1429 	tasklet_disable(&ctx->tasklet);
1430 
1431 	ctx->flushing = true;
1432 	context_tasklet((unsigned long)ctx);
1433 	ctx->flushing = false;
1434 
1435 	tasklet_enable(&ctx->tasklet);
1436 }
1437 
1438 static int handle_at_packet(struct context *context,
1439 			    struct descriptor *d,
1440 			    struct descriptor *last)
1441 {
1442 	struct driver_data *driver_data;
1443 	struct fw_packet *packet;
1444 	struct fw_ohci *ohci = context->ohci;
1445 	int evt;
1446 
1447 	if (last->transfer_status == 0 && !context->flushing)
1448 		/* This descriptor isn't done yet, stop iteration. */
1449 		return 0;
1450 
1451 	driver_data = (struct driver_data *) &d[3];
1452 	packet = driver_data->packet;
1453 	if (packet == NULL)
1454 		/* This packet was cancelled, just continue. */
1455 		return 1;
1456 
1457 	if (packet->payload_mapped)
1458 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1459 				 packet->payload_length, DMA_TO_DEVICE);
1460 
1461 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1462 	packet->timestamp = le16_to_cpu(last->res_count);
1463 
1464 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, evt);
1465 
1466 	switch (evt) {
1467 	case OHCI1394_evt_timeout:
1468 		/* Async response transmit timed out. */
1469 		packet->ack = RCODE_CANCELLED;
1470 		break;
1471 
1472 	case OHCI1394_evt_flushed:
1473 		/*
1474 		 * The packet was flushed should give same error as
1475 		 * when we try to use a stale generation count.
1476 		 */
1477 		packet->ack = RCODE_GENERATION;
1478 		break;
1479 
1480 	case OHCI1394_evt_missing_ack:
1481 		if (context->flushing)
1482 			packet->ack = RCODE_GENERATION;
1483 		else {
1484 			/*
1485 			 * Using a valid (current) generation count, but the
1486 			 * node is not on the bus or not sending acks.
1487 			 */
1488 			packet->ack = RCODE_NO_ACK;
1489 		}
1490 		break;
1491 
1492 	case ACK_COMPLETE + 0x10:
1493 	case ACK_PENDING + 0x10:
1494 	case ACK_BUSY_X + 0x10:
1495 	case ACK_BUSY_A + 0x10:
1496 	case ACK_BUSY_B + 0x10:
1497 	case ACK_DATA_ERROR + 0x10:
1498 	case ACK_TYPE_ERROR + 0x10:
1499 		packet->ack = evt - 0x10;
1500 		break;
1501 
1502 	case OHCI1394_evt_no_status:
1503 		if (context->flushing) {
1504 			packet->ack = RCODE_GENERATION;
1505 			break;
1506 		}
1507 		/* fall through */
1508 
1509 	default:
1510 		packet->ack = RCODE_SEND_ERROR;
1511 		break;
1512 	}
1513 
1514 	packet->callback(packet, &ohci->card, packet->ack);
1515 
1516 	return 1;
1517 }
1518 
1519 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1520 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1521 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1522 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1523 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
1524 
1525 static void handle_local_rom(struct fw_ohci *ohci,
1526 			     struct fw_packet *packet, u32 csr)
1527 {
1528 	struct fw_packet response;
1529 	int tcode, length, i;
1530 
1531 	tcode = HEADER_GET_TCODE(packet->header[0]);
1532 	if (TCODE_IS_BLOCK_PACKET(tcode))
1533 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1534 	else
1535 		length = 4;
1536 
1537 	i = csr - CSR_CONFIG_ROM;
1538 	if (i + length > CONFIG_ROM_SIZE) {
1539 		fw_fill_response(&response, packet->header,
1540 				 RCODE_ADDRESS_ERROR, NULL, 0);
1541 	} else if (!TCODE_IS_READ_REQUEST(tcode)) {
1542 		fw_fill_response(&response, packet->header,
1543 				 RCODE_TYPE_ERROR, NULL, 0);
1544 	} else {
1545 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1546 				 (void *) ohci->config_rom + i, length);
1547 	}
1548 
1549 	fw_core_handle_response(&ohci->card, &response);
1550 }
1551 
1552 static void handle_local_lock(struct fw_ohci *ohci,
1553 			      struct fw_packet *packet, u32 csr)
1554 {
1555 	struct fw_packet response;
1556 	int tcode, length, ext_tcode, sel, try;
1557 	__be32 *payload, lock_old;
1558 	u32 lock_arg, lock_data;
1559 
1560 	tcode = HEADER_GET_TCODE(packet->header[0]);
1561 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1562 	payload = packet->payload;
1563 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1564 
1565 	if (tcode == TCODE_LOCK_REQUEST &&
1566 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1567 		lock_arg = be32_to_cpu(payload[0]);
1568 		lock_data = be32_to_cpu(payload[1]);
1569 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1570 		lock_arg = 0;
1571 		lock_data = 0;
1572 	} else {
1573 		fw_fill_response(&response, packet->header,
1574 				 RCODE_TYPE_ERROR, NULL, 0);
1575 		goto out;
1576 	}
1577 
1578 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1579 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1580 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1581 	reg_write(ohci, OHCI1394_CSRControl, sel);
1582 
1583 	for (try = 0; try < 20; try++)
1584 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1585 			lock_old = cpu_to_be32(reg_read(ohci,
1586 							OHCI1394_CSRData));
1587 			fw_fill_response(&response, packet->header,
1588 					 RCODE_COMPLETE,
1589 					 &lock_old, sizeof(lock_old));
1590 			goto out;
1591 		}
1592 
1593 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
1594 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1595 
1596  out:
1597 	fw_core_handle_response(&ohci->card, &response);
1598 }
1599 
1600 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1601 {
1602 	u64 offset, csr;
1603 
1604 	if (ctx == &ctx->ohci->at_request_ctx) {
1605 		packet->ack = ACK_PENDING;
1606 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1607 	}
1608 
1609 	offset =
1610 		((unsigned long long)
1611 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1612 		packet->header[2];
1613 	csr = offset - CSR_REGISTER_BASE;
1614 
1615 	/* Handle config rom reads. */
1616 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1617 		handle_local_rom(ctx->ohci, packet, csr);
1618 	else switch (csr) {
1619 	case CSR_BUS_MANAGER_ID:
1620 	case CSR_BANDWIDTH_AVAILABLE:
1621 	case CSR_CHANNELS_AVAILABLE_HI:
1622 	case CSR_CHANNELS_AVAILABLE_LO:
1623 		handle_local_lock(ctx->ohci, packet, csr);
1624 		break;
1625 	default:
1626 		if (ctx == &ctx->ohci->at_request_ctx)
1627 			fw_core_handle_request(&ctx->ohci->card, packet);
1628 		else
1629 			fw_core_handle_response(&ctx->ohci->card, packet);
1630 		break;
1631 	}
1632 
1633 	if (ctx == &ctx->ohci->at_response_ctx) {
1634 		packet->ack = ACK_COMPLETE;
1635 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1636 	}
1637 }
1638 
1639 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1640 {
1641 	unsigned long flags;
1642 	int ret;
1643 
1644 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1645 
1646 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1647 	    ctx->ohci->generation == packet->generation) {
1648 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1649 		handle_local_request(ctx, packet);
1650 		return;
1651 	}
1652 
1653 	ret = at_context_queue_packet(ctx, packet);
1654 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1655 
1656 	if (ret < 0)
1657 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1658 
1659 }
1660 
1661 static void detect_dead_context(struct fw_ohci *ohci,
1662 				const char *name, unsigned int regs)
1663 {
1664 	u32 ctl;
1665 
1666 	ctl = reg_read(ohci, CONTROL_SET(regs));
1667 	if (ctl & CONTEXT_DEAD)
1668 		ohci_err(ohci, "DMA context %s has stopped, error code: %s\n",
1669 			name, evts[ctl & 0x1f]);
1670 }
1671 
1672 static void handle_dead_contexts(struct fw_ohci *ohci)
1673 {
1674 	unsigned int i;
1675 	char name[8];
1676 
1677 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1678 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1679 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1680 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1681 	for (i = 0; i < 32; ++i) {
1682 		if (!(ohci->it_context_support & (1 << i)))
1683 			continue;
1684 		sprintf(name, "IT%u", i);
1685 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1686 	}
1687 	for (i = 0; i < 32; ++i) {
1688 		if (!(ohci->ir_context_support & (1 << i)))
1689 			continue;
1690 		sprintf(name, "IR%u", i);
1691 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1692 	}
1693 	/* TODO: maybe try to flush and restart the dead contexts */
1694 }
1695 
1696 static u32 cycle_timer_ticks(u32 cycle_timer)
1697 {
1698 	u32 ticks;
1699 
1700 	ticks = cycle_timer & 0xfff;
1701 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1702 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1703 
1704 	return ticks;
1705 }
1706 
1707 /*
1708  * Some controllers exhibit one or more of the following bugs when updating the
1709  * iso cycle timer register:
1710  *  - When the lowest six bits are wrapping around to zero, a read that happens
1711  *    at the same time will return garbage in the lowest ten bits.
1712  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1713  *    not incremented for about 60 ns.
1714  *  - Occasionally, the entire register reads zero.
1715  *
1716  * To catch these, we read the register three times and ensure that the
1717  * difference between each two consecutive reads is approximately the same, i.e.
1718  * less than twice the other.  Furthermore, any negative difference indicates an
1719  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1720  * execute, so we have enough precision to compute the ratio of the differences.)
1721  */
1722 static u32 get_cycle_time(struct fw_ohci *ohci)
1723 {
1724 	u32 c0, c1, c2;
1725 	u32 t0, t1, t2;
1726 	s32 diff01, diff12;
1727 	int i;
1728 
1729 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1730 
1731 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1732 		i = 0;
1733 		c1 = c2;
1734 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1735 		do {
1736 			c0 = c1;
1737 			c1 = c2;
1738 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1739 			t0 = cycle_timer_ticks(c0);
1740 			t1 = cycle_timer_ticks(c1);
1741 			t2 = cycle_timer_ticks(c2);
1742 			diff01 = t1 - t0;
1743 			diff12 = t2 - t1;
1744 		} while ((diff01 <= 0 || diff12 <= 0 ||
1745 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1746 			 && i++ < 20);
1747 	}
1748 
1749 	return c2;
1750 }
1751 
1752 /*
1753  * This function has to be called at least every 64 seconds.  The bus_time
1754  * field stores not only the upper 25 bits of the BUS_TIME register but also
1755  * the most significant bit of the cycle timer in bit 6 so that we can detect
1756  * changes in this bit.
1757  */
1758 static u32 update_bus_time(struct fw_ohci *ohci)
1759 {
1760 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1761 
1762 	if (unlikely(!ohci->bus_time_running)) {
1763 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds);
1764 		ohci->bus_time = (lower_32_bits(get_seconds()) & ~0x7f) |
1765 		                 (cycle_time_seconds & 0x40);
1766 		ohci->bus_time_running = true;
1767 	}
1768 
1769 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1770 		ohci->bus_time += 0x40;
1771 
1772 	return ohci->bus_time | cycle_time_seconds;
1773 }
1774 
1775 static int get_status_for_port(struct fw_ohci *ohci, int port_index)
1776 {
1777 	int reg;
1778 
1779 	mutex_lock(&ohci->phy_reg_mutex);
1780 	reg = write_phy_reg(ohci, 7, port_index);
1781 	if (reg >= 0)
1782 		reg = read_phy_reg(ohci, 8);
1783 	mutex_unlock(&ohci->phy_reg_mutex);
1784 	if (reg < 0)
1785 		return reg;
1786 
1787 	switch (reg & 0x0f) {
1788 	case 0x06:
1789 		return 2;	/* is child node (connected to parent node) */
1790 	case 0x0e:
1791 		return 3;	/* is parent node (connected to child node) */
1792 	}
1793 	return 1;		/* not connected */
1794 }
1795 
1796 static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
1797 	int self_id_count)
1798 {
1799 	int i;
1800 	u32 entry;
1801 
1802 	for (i = 0; i < self_id_count; i++) {
1803 		entry = ohci->self_id_buffer[i];
1804 		if ((self_id & 0xff000000) == (entry & 0xff000000))
1805 			return -1;
1806 		if ((self_id & 0xff000000) < (entry & 0xff000000))
1807 			return i;
1808 	}
1809 	return i;
1810 }
1811 
1812 static int initiated_reset(struct fw_ohci *ohci)
1813 {
1814 	int reg;
1815 	int ret = 0;
1816 
1817 	mutex_lock(&ohci->phy_reg_mutex);
1818 	reg = write_phy_reg(ohci, 7, 0xe0); /* Select page 7 */
1819 	if (reg >= 0) {
1820 		reg = read_phy_reg(ohci, 8);
1821 		reg |= 0x40;
1822 		reg = write_phy_reg(ohci, 8, reg); /* set PMODE bit */
1823 		if (reg >= 0) {
1824 			reg = read_phy_reg(ohci, 12); /* read register 12 */
1825 			if (reg >= 0) {
1826 				if ((reg & 0x08) == 0x08) {
1827 					/* bit 3 indicates "initiated reset" */
1828 					ret = 0x2;
1829 				}
1830 			}
1831 		}
1832 	}
1833 	mutex_unlock(&ohci->phy_reg_mutex);
1834 	return ret;
1835 }
1836 
1837 /*
1838  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
1839  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
1840  * Construct the selfID from phy register contents.
1841  */
1842 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
1843 {
1844 	int reg, i, pos, status;
1845 	/* link active 1, speed 3, bridge 0, contender 1, more packets 0 */
1846 	u32 self_id = 0x8040c800;
1847 
1848 	reg = reg_read(ohci, OHCI1394_NodeID);
1849 	if (!(reg & OHCI1394_NodeID_idValid)) {
1850 		ohci_notice(ohci,
1851 			    "node ID not valid, new bus reset in progress\n");
1852 		return -EBUSY;
1853 	}
1854 	self_id |= ((reg & 0x3f) << 24); /* phy ID */
1855 
1856 	reg = ohci_read_phy_reg(&ohci->card, 4);
1857 	if (reg < 0)
1858 		return reg;
1859 	self_id |= ((reg & 0x07) << 8); /* power class */
1860 
1861 	reg = ohci_read_phy_reg(&ohci->card, 1);
1862 	if (reg < 0)
1863 		return reg;
1864 	self_id |= ((reg & 0x3f) << 16); /* gap count */
1865 
1866 	for (i = 0; i < 3; i++) {
1867 		status = get_status_for_port(ohci, i);
1868 		if (status < 0)
1869 			return status;
1870 		self_id |= ((status & 0x3) << (6 - (i * 2)));
1871 	}
1872 
1873 	self_id |= initiated_reset(ohci);
1874 
1875 	pos = get_self_id_pos(ohci, self_id, self_id_count);
1876 	if (pos >= 0) {
1877 		memmove(&(ohci->self_id_buffer[pos+1]),
1878 			&(ohci->self_id_buffer[pos]),
1879 			(self_id_count - pos) * sizeof(*ohci->self_id_buffer));
1880 		ohci->self_id_buffer[pos] = self_id;
1881 		self_id_count++;
1882 	}
1883 	return self_id_count;
1884 }
1885 
1886 static void bus_reset_work(struct work_struct *work)
1887 {
1888 	struct fw_ohci *ohci =
1889 		container_of(work, struct fw_ohci, bus_reset_work);
1890 	int self_id_count, generation, new_generation, i, j;
1891 	u32 reg;
1892 	void *free_rom = NULL;
1893 	dma_addr_t free_rom_bus = 0;
1894 	bool is_new_root;
1895 
1896 	reg = reg_read(ohci, OHCI1394_NodeID);
1897 	if (!(reg & OHCI1394_NodeID_idValid)) {
1898 		ohci_notice(ohci,
1899 			    "node ID not valid, new bus reset in progress\n");
1900 		return;
1901 	}
1902 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1903 		ohci_notice(ohci, "malconfigured bus\n");
1904 		return;
1905 	}
1906 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1907 			       OHCI1394_NodeID_nodeNumber);
1908 
1909 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1910 	if (!(ohci->is_root && is_new_root))
1911 		reg_write(ohci, OHCI1394_LinkControlSet,
1912 			  OHCI1394_LinkControl_cycleMaster);
1913 	ohci->is_root = is_new_root;
1914 
1915 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1916 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1917 		ohci_notice(ohci, "self ID receive error\n");
1918 		return;
1919 	}
1920 	/*
1921 	 * The count in the SelfIDCount register is the number of
1922 	 * bytes in the self ID receive buffer.  Since we also receive
1923 	 * the inverted quadlets and a header quadlet, we shift one
1924 	 * bit extra to get the actual number of self IDs.
1925 	 */
1926 	self_id_count = (reg >> 3) & 0xff;
1927 
1928 	if (self_id_count > 252) {
1929 		ohci_notice(ohci, "bad selfIDSize (%08x)\n", reg);
1930 		return;
1931 	}
1932 
1933 	generation = (cond_le32_to_cpu(ohci->self_id[0]) >> 16) & 0xff;
1934 	rmb();
1935 
1936 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1937 		u32 id  = cond_le32_to_cpu(ohci->self_id[i]);
1938 		u32 id2 = cond_le32_to_cpu(ohci->self_id[i + 1]);
1939 
1940 		if (id != ~id2) {
1941 			/*
1942 			 * If the invalid data looks like a cycle start packet,
1943 			 * it's likely to be the result of the cycle master
1944 			 * having a wrong gap count.  In this case, the self IDs
1945 			 * so far are valid and should be processed so that the
1946 			 * bus manager can then correct the gap count.
1947 			 */
1948 			if (id == 0xffff008f) {
1949 				ohci_notice(ohci, "ignoring spurious self IDs\n");
1950 				self_id_count = j;
1951 				break;
1952 			}
1953 
1954 			ohci_notice(ohci, "bad self ID %d/%d (%08x != ~%08x)\n",
1955 				    j, self_id_count, id, id2);
1956 			return;
1957 		}
1958 		ohci->self_id_buffer[j] = id;
1959 	}
1960 
1961 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
1962 		self_id_count = find_and_insert_self_id(ohci, self_id_count);
1963 		if (self_id_count < 0) {
1964 			ohci_notice(ohci,
1965 				    "could not construct local self ID\n");
1966 			return;
1967 		}
1968 	}
1969 
1970 	if (self_id_count == 0) {
1971 		ohci_notice(ohci, "no self IDs\n");
1972 		return;
1973 	}
1974 	rmb();
1975 
1976 	/*
1977 	 * Check the consistency of the self IDs we just read.  The
1978 	 * problem we face is that a new bus reset can start while we
1979 	 * read out the self IDs from the DMA buffer. If this happens,
1980 	 * the DMA buffer will be overwritten with new self IDs and we
1981 	 * will read out inconsistent data.  The OHCI specification
1982 	 * (section 11.2) recommends a technique similar to
1983 	 * linux/seqlock.h, where we remember the generation of the
1984 	 * self IDs in the buffer before reading them out and compare
1985 	 * it to the current generation after reading them out.  If
1986 	 * the two generations match we know we have a consistent set
1987 	 * of self IDs.
1988 	 */
1989 
1990 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1991 	if (new_generation != generation) {
1992 		ohci_notice(ohci, "new bus reset, discarding self ids\n");
1993 		return;
1994 	}
1995 
1996 	/* FIXME: Document how the locking works. */
1997 	spin_lock_irq(&ohci->lock);
1998 
1999 	ohci->generation = -1; /* prevent AT packet queueing */
2000 	context_stop(&ohci->at_request_ctx);
2001 	context_stop(&ohci->at_response_ctx);
2002 
2003 	spin_unlock_irq(&ohci->lock);
2004 
2005 	/*
2006 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
2007 	 * packets in the AT queues and software needs to drain them.
2008 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
2009 	 */
2010 	at_context_flush(&ohci->at_request_ctx);
2011 	at_context_flush(&ohci->at_response_ctx);
2012 
2013 	spin_lock_irq(&ohci->lock);
2014 
2015 	ohci->generation = generation;
2016 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
2017 
2018 	if (ohci->quirks & QUIRK_RESET_PACKET)
2019 		ohci->request_generation = generation;
2020 
2021 	/*
2022 	 * This next bit is unrelated to the AT context stuff but we
2023 	 * have to do it under the spinlock also.  If a new config rom
2024 	 * was set up before this reset, the old one is now no longer
2025 	 * in use and we can free it. Update the config rom pointers
2026 	 * to point to the current config rom and clear the
2027 	 * next_config_rom pointer so a new update can take place.
2028 	 */
2029 
2030 	if (ohci->next_config_rom != NULL) {
2031 		if (ohci->next_config_rom != ohci->config_rom) {
2032 			free_rom      = ohci->config_rom;
2033 			free_rom_bus  = ohci->config_rom_bus;
2034 		}
2035 		ohci->config_rom      = ohci->next_config_rom;
2036 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
2037 		ohci->next_config_rom = NULL;
2038 
2039 		/*
2040 		 * Restore config_rom image and manually update
2041 		 * config_rom registers.  Writing the header quadlet
2042 		 * will indicate that the config rom is ready, so we
2043 		 * do that last.
2044 		 */
2045 		reg_write(ohci, OHCI1394_BusOptions,
2046 			  be32_to_cpu(ohci->config_rom[2]));
2047 		ohci->config_rom[0] = ohci->next_header;
2048 		reg_write(ohci, OHCI1394_ConfigROMhdr,
2049 			  be32_to_cpu(ohci->next_header));
2050 	}
2051 
2052 	if (param_remote_dma) {
2053 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
2054 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
2055 	}
2056 
2057 	spin_unlock_irq(&ohci->lock);
2058 
2059 	if (free_rom)
2060 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2061 				  free_rom, free_rom_bus);
2062 
2063 	log_selfids(ohci, generation, self_id_count);
2064 
2065 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
2066 				 self_id_count, ohci->self_id_buffer,
2067 				 ohci->csr_state_setclear_abdicate);
2068 	ohci->csr_state_setclear_abdicate = false;
2069 }
2070 
2071 static irqreturn_t irq_handler(int irq, void *data)
2072 {
2073 	struct fw_ohci *ohci = data;
2074 	u32 event, iso_event;
2075 	int i;
2076 
2077 	event = reg_read(ohci, OHCI1394_IntEventClear);
2078 
2079 	if (!event || !~event)
2080 		return IRQ_NONE;
2081 
2082 	/*
2083 	 * busReset and postedWriteErr must not be cleared yet
2084 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
2085 	 */
2086 	reg_write(ohci, OHCI1394_IntEventClear,
2087 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
2088 	log_irqs(ohci, event);
2089 
2090 	if (event & OHCI1394_selfIDComplete)
2091 		queue_work(selfid_workqueue, &ohci->bus_reset_work);
2092 
2093 	if (event & OHCI1394_RQPkt)
2094 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
2095 
2096 	if (event & OHCI1394_RSPkt)
2097 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
2098 
2099 	if (event & OHCI1394_reqTxComplete)
2100 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
2101 
2102 	if (event & OHCI1394_respTxComplete)
2103 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
2104 
2105 	if (event & OHCI1394_isochRx) {
2106 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
2107 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
2108 
2109 		while (iso_event) {
2110 			i = ffs(iso_event) - 1;
2111 			tasklet_schedule(
2112 				&ohci->ir_context_list[i].context.tasklet);
2113 			iso_event &= ~(1 << i);
2114 		}
2115 	}
2116 
2117 	if (event & OHCI1394_isochTx) {
2118 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
2119 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
2120 
2121 		while (iso_event) {
2122 			i = ffs(iso_event) - 1;
2123 			tasklet_schedule(
2124 				&ohci->it_context_list[i].context.tasklet);
2125 			iso_event &= ~(1 << i);
2126 		}
2127 	}
2128 
2129 	if (unlikely(event & OHCI1394_regAccessFail))
2130 		ohci_err(ohci, "register access failure\n");
2131 
2132 	if (unlikely(event & OHCI1394_postedWriteErr)) {
2133 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
2134 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
2135 		reg_write(ohci, OHCI1394_IntEventClear,
2136 			  OHCI1394_postedWriteErr);
2137 		if (printk_ratelimit())
2138 			ohci_err(ohci, "PCI posted write error\n");
2139 	}
2140 
2141 	if (unlikely(event & OHCI1394_cycleTooLong)) {
2142 		if (printk_ratelimit())
2143 			ohci_notice(ohci, "isochronous cycle too long\n");
2144 		reg_write(ohci, OHCI1394_LinkControlSet,
2145 			  OHCI1394_LinkControl_cycleMaster);
2146 	}
2147 
2148 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
2149 		/*
2150 		 * We need to clear this event bit in order to make
2151 		 * cycleMatch isochronous I/O work.  In theory we should
2152 		 * stop active cycleMatch iso contexts now and restart
2153 		 * them at least two cycles later.  (FIXME?)
2154 		 */
2155 		if (printk_ratelimit())
2156 			ohci_notice(ohci, "isochronous cycle inconsistent\n");
2157 	}
2158 
2159 	if (unlikely(event & OHCI1394_unrecoverableError))
2160 		handle_dead_contexts(ohci);
2161 
2162 	if (event & OHCI1394_cycle64Seconds) {
2163 		spin_lock(&ohci->lock);
2164 		update_bus_time(ohci);
2165 		spin_unlock(&ohci->lock);
2166 	} else
2167 		flush_writes(ohci);
2168 
2169 	return IRQ_HANDLED;
2170 }
2171 
2172 static int software_reset(struct fw_ohci *ohci)
2173 {
2174 	u32 val;
2175 	int i;
2176 
2177 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
2178 	for (i = 0; i < 500; i++) {
2179 		val = reg_read(ohci, OHCI1394_HCControlSet);
2180 		if (!~val)
2181 			return -ENODEV; /* Card was ejected. */
2182 
2183 		if (!(val & OHCI1394_HCControl_softReset))
2184 			return 0;
2185 
2186 		msleep(1);
2187 	}
2188 
2189 	return -EBUSY;
2190 }
2191 
2192 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
2193 {
2194 	size_t size = length * 4;
2195 
2196 	memcpy(dest, src, size);
2197 	if (size < CONFIG_ROM_SIZE)
2198 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
2199 }
2200 
2201 static int configure_1394a_enhancements(struct fw_ohci *ohci)
2202 {
2203 	bool enable_1394a;
2204 	int ret, clear, set, offset;
2205 
2206 	/* Check if the driver should configure link and PHY. */
2207 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
2208 	      OHCI1394_HCControl_programPhyEnable))
2209 		return 0;
2210 
2211 	/* Paranoia: check whether the PHY supports 1394a, too. */
2212 	enable_1394a = false;
2213 	ret = read_phy_reg(ohci, 2);
2214 	if (ret < 0)
2215 		return ret;
2216 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2217 		ret = read_paged_phy_reg(ohci, 1, 8);
2218 		if (ret < 0)
2219 			return ret;
2220 		if (ret >= 1)
2221 			enable_1394a = true;
2222 	}
2223 
2224 	if (ohci->quirks & QUIRK_NO_1394A)
2225 		enable_1394a = false;
2226 
2227 	/* Configure PHY and link consistently. */
2228 	if (enable_1394a) {
2229 		clear = 0;
2230 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2231 	} else {
2232 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2233 		set = 0;
2234 	}
2235 	ret = update_phy_reg(ohci, 5, clear, set);
2236 	if (ret < 0)
2237 		return ret;
2238 
2239 	if (enable_1394a)
2240 		offset = OHCI1394_HCControlSet;
2241 	else
2242 		offset = OHCI1394_HCControlClear;
2243 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2244 
2245 	/* Clean up: configuration has been taken care of. */
2246 	reg_write(ohci, OHCI1394_HCControlClear,
2247 		  OHCI1394_HCControl_programPhyEnable);
2248 
2249 	return 0;
2250 }
2251 
2252 static int probe_tsb41ba3d(struct fw_ohci *ohci)
2253 {
2254 	/* TI vendor ID = 0x080028, TSB41BA3D product ID = 0x833005 (sic) */
2255 	static const u8 id[] = { 0x08, 0x00, 0x28, 0x83, 0x30, 0x05, };
2256 	int reg, i;
2257 
2258 	reg = read_phy_reg(ohci, 2);
2259 	if (reg < 0)
2260 		return reg;
2261 	if ((reg & PHY_EXTENDED_REGISTERS) != PHY_EXTENDED_REGISTERS)
2262 		return 0;
2263 
2264 	for (i = ARRAY_SIZE(id) - 1; i >= 0; i--) {
2265 		reg = read_paged_phy_reg(ohci, 1, i + 10);
2266 		if (reg < 0)
2267 			return reg;
2268 		if (reg != id[i])
2269 			return 0;
2270 	}
2271 	return 1;
2272 }
2273 
2274 static int ohci_enable(struct fw_card *card,
2275 		       const __be32 *config_rom, size_t length)
2276 {
2277 	struct fw_ohci *ohci = fw_ohci(card);
2278 	u32 lps, version, irqs;
2279 	int i, ret;
2280 
2281 	ret = software_reset(ohci);
2282 	if (ret < 0) {
2283 		ohci_err(ohci, "failed to reset ohci card\n");
2284 		return ret;
2285 	}
2286 
2287 	/*
2288 	 * Now enable LPS, which we need in order to start accessing
2289 	 * most of the registers.  In fact, on some cards (ALI M5251),
2290 	 * accessing registers in the SClk domain without LPS enabled
2291 	 * will lock up the machine.  Wait 50msec to make sure we have
2292 	 * full link enabled.  However, with some cards (well, at least
2293 	 * a JMicron PCIe card), we have to try again sometimes.
2294 	 *
2295 	 * TI TSB82AA2 + TSB81BA3(A) cards signal LPS enabled early but
2296 	 * cannot actually use the phy at that time.  These need tens of
2297 	 * millisecods pause between LPS write and first phy access too.
2298 	 */
2299 
2300 	reg_write(ohci, OHCI1394_HCControlSet,
2301 		  OHCI1394_HCControl_LPS |
2302 		  OHCI1394_HCControl_postedWriteEnable);
2303 	flush_writes(ohci);
2304 
2305 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2306 		msleep(50);
2307 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2308 		      OHCI1394_HCControl_LPS;
2309 	}
2310 
2311 	if (!lps) {
2312 		ohci_err(ohci, "failed to set Link Power Status\n");
2313 		return -EIO;
2314 	}
2315 
2316 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2317 		ret = probe_tsb41ba3d(ohci);
2318 		if (ret < 0)
2319 			return ret;
2320 		if (ret)
2321 			ohci_notice(ohci, "local TSB41BA3D phy\n");
2322 		else
2323 			ohci->quirks &= ~QUIRK_TI_SLLZ059;
2324 	}
2325 
2326 	reg_write(ohci, OHCI1394_HCControlClear,
2327 		  OHCI1394_HCControl_noByteSwapData);
2328 
2329 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2330 	reg_write(ohci, OHCI1394_LinkControlSet,
2331 		  OHCI1394_LinkControl_cycleTimerEnable |
2332 		  OHCI1394_LinkControl_cycleMaster);
2333 
2334 	reg_write(ohci, OHCI1394_ATRetries,
2335 		  OHCI1394_MAX_AT_REQ_RETRIES |
2336 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2337 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2338 		  (200 << 16));
2339 
2340 	ohci->bus_time_running = false;
2341 
2342 	for (i = 0; i < 32; i++)
2343 		if (ohci->ir_context_support & (1 << i))
2344 			reg_write(ohci, OHCI1394_IsoRcvContextControlClear(i),
2345 				  IR_CONTEXT_MULTI_CHANNEL_MODE);
2346 
2347 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2348 	if (version >= OHCI_VERSION_1_1) {
2349 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2350 			  0xfffffffe);
2351 		card->broadcast_channel_auto_allocated = true;
2352 	}
2353 
2354 	/* Get implemented bits of the priority arbitration request counter. */
2355 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2356 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2357 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2358 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2359 
2360 	reg_write(ohci, OHCI1394_PhyUpperBound, FW_MAX_PHYSICAL_RANGE >> 16);
2361 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2362 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2363 
2364 	ret = configure_1394a_enhancements(ohci);
2365 	if (ret < 0)
2366 		return ret;
2367 
2368 	/* Activate link_on bit and contender bit in our self ID packets.*/
2369 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2370 	if (ret < 0)
2371 		return ret;
2372 
2373 	/*
2374 	 * When the link is not yet enabled, the atomic config rom
2375 	 * update mechanism described below in ohci_set_config_rom()
2376 	 * is not active.  We have to update ConfigRomHeader and
2377 	 * BusOptions manually, and the write to ConfigROMmap takes
2378 	 * effect immediately.  We tie this to the enabling of the
2379 	 * link, so we have a valid config rom before enabling - the
2380 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2381 	 * values before enabling.
2382 	 *
2383 	 * However, when the ConfigROMmap is written, some controllers
2384 	 * always read back quadlets 0 and 2 from the config rom to
2385 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2386 	 * They shouldn't do that in this initial case where the link
2387 	 * isn't enabled.  This means we have to use the same
2388 	 * workaround here, setting the bus header to 0 and then write
2389 	 * the right values in the bus reset tasklet.
2390 	 */
2391 
2392 	if (config_rom) {
2393 		ohci->next_config_rom =
2394 			dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2395 					   &ohci->next_config_rom_bus,
2396 					   GFP_KERNEL);
2397 		if (ohci->next_config_rom == NULL)
2398 			return -ENOMEM;
2399 
2400 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2401 	} else {
2402 		/*
2403 		 * In the suspend case, config_rom is NULL, which
2404 		 * means that we just reuse the old config rom.
2405 		 */
2406 		ohci->next_config_rom = ohci->config_rom;
2407 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2408 	}
2409 
2410 	ohci->next_header = ohci->next_config_rom[0];
2411 	ohci->next_config_rom[0] = 0;
2412 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2413 	reg_write(ohci, OHCI1394_BusOptions,
2414 		  be32_to_cpu(ohci->next_config_rom[2]));
2415 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2416 
2417 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2418 
2419 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2420 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2421 		OHCI1394_isochTx | OHCI1394_isochRx |
2422 		OHCI1394_postedWriteErr |
2423 		OHCI1394_selfIDComplete |
2424 		OHCI1394_regAccessFail |
2425 		OHCI1394_cycleInconsistent |
2426 		OHCI1394_unrecoverableError |
2427 		OHCI1394_cycleTooLong |
2428 		OHCI1394_masterIntEnable;
2429 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2430 		irqs |= OHCI1394_busReset;
2431 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2432 
2433 	reg_write(ohci, OHCI1394_HCControlSet,
2434 		  OHCI1394_HCControl_linkEnable |
2435 		  OHCI1394_HCControl_BIBimageValid);
2436 
2437 	reg_write(ohci, OHCI1394_LinkControlSet,
2438 		  OHCI1394_LinkControl_rcvSelfID |
2439 		  OHCI1394_LinkControl_rcvPhyPkt);
2440 
2441 	ar_context_run(&ohci->ar_request_ctx);
2442 	ar_context_run(&ohci->ar_response_ctx);
2443 
2444 	flush_writes(ohci);
2445 
2446 	/* We are ready to go, reset bus to finish initialization. */
2447 	fw_schedule_bus_reset(&ohci->card, false, true);
2448 
2449 	return 0;
2450 }
2451 
2452 static int ohci_set_config_rom(struct fw_card *card,
2453 			       const __be32 *config_rom, size_t length)
2454 {
2455 	struct fw_ohci *ohci;
2456 	__be32 *next_config_rom;
2457 	dma_addr_t uninitialized_var(next_config_rom_bus);
2458 
2459 	ohci = fw_ohci(card);
2460 
2461 	/*
2462 	 * When the OHCI controller is enabled, the config rom update
2463 	 * mechanism is a bit tricky, but easy enough to use.  See
2464 	 * section 5.5.6 in the OHCI specification.
2465 	 *
2466 	 * The OHCI controller caches the new config rom address in a
2467 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2468 	 * for the changes to take place.  When the bus reset is
2469 	 * detected, the controller loads the new values for the
2470 	 * ConfigRomHeader and BusOptions registers from the specified
2471 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2472 	 * shadow register. All automatically and atomically.
2473 	 *
2474 	 * Now, there's a twist to this story.  The automatic load of
2475 	 * ConfigRomHeader and BusOptions doesn't honor the
2476 	 * noByteSwapData bit, so with a be32 config rom, the
2477 	 * controller will load be32 values in to these registers
2478 	 * during the atomic update, even on litte endian
2479 	 * architectures.  The workaround we use is to put a 0 in the
2480 	 * header quadlet; 0 is endian agnostic and means that the
2481 	 * config rom isn't ready yet.  In the bus reset tasklet we
2482 	 * then set up the real values for the two registers.
2483 	 *
2484 	 * We use ohci->lock to avoid racing with the code that sets
2485 	 * ohci->next_config_rom to NULL (see bus_reset_work).
2486 	 */
2487 
2488 	next_config_rom =
2489 		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2490 				   &next_config_rom_bus, GFP_KERNEL);
2491 	if (next_config_rom == NULL)
2492 		return -ENOMEM;
2493 
2494 	spin_lock_irq(&ohci->lock);
2495 
2496 	/*
2497 	 * If there is not an already pending config_rom update,
2498 	 * push our new allocation into the ohci->next_config_rom
2499 	 * and then mark the local variable as null so that we
2500 	 * won't deallocate the new buffer.
2501 	 *
2502 	 * OTOH, if there is a pending config_rom update, just
2503 	 * use that buffer with the new config_rom data, and
2504 	 * let this routine free the unused DMA allocation.
2505 	 */
2506 
2507 	if (ohci->next_config_rom == NULL) {
2508 		ohci->next_config_rom = next_config_rom;
2509 		ohci->next_config_rom_bus = next_config_rom_bus;
2510 		next_config_rom = NULL;
2511 	}
2512 
2513 	copy_config_rom(ohci->next_config_rom, config_rom, length);
2514 
2515 	ohci->next_header = config_rom[0];
2516 	ohci->next_config_rom[0] = 0;
2517 
2518 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2519 
2520 	spin_unlock_irq(&ohci->lock);
2521 
2522 	/* If we didn't use the DMA allocation, delete it. */
2523 	if (next_config_rom != NULL)
2524 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2525 				  next_config_rom, next_config_rom_bus);
2526 
2527 	/*
2528 	 * Now initiate a bus reset to have the changes take
2529 	 * effect. We clean up the old config rom memory and DMA
2530 	 * mappings in the bus reset tasklet, since the OHCI
2531 	 * controller could need to access it before the bus reset
2532 	 * takes effect.
2533 	 */
2534 
2535 	fw_schedule_bus_reset(&ohci->card, true, true);
2536 
2537 	return 0;
2538 }
2539 
2540 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2541 {
2542 	struct fw_ohci *ohci = fw_ohci(card);
2543 
2544 	at_context_transmit(&ohci->at_request_ctx, packet);
2545 }
2546 
2547 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2548 {
2549 	struct fw_ohci *ohci = fw_ohci(card);
2550 
2551 	at_context_transmit(&ohci->at_response_ctx, packet);
2552 }
2553 
2554 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2555 {
2556 	struct fw_ohci *ohci = fw_ohci(card);
2557 	struct context *ctx = &ohci->at_request_ctx;
2558 	struct driver_data *driver_data = packet->driver_data;
2559 	int ret = -ENOENT;
2560 
2561 	tasklet_disable(&ctx->tasklet);
2562 
2563 	if (packet->ack != 0)
2564 		goto out;
2565 
2566 	if (packet->payload_mapped)
2567 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2568 				 packet->payload_length, DMA_TO_DEVICE);
2569 
2570 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, 0x20);
2571 	driver_data->packet = NULL;
2572 	packet->ack = RCODE_CANCELLED;
2573 	packet->callback(packet, &ohci->card, packet->ack);
2574 	ret = 0;
2575  out:
2576 	tasklet_enable(&ctx->tasklet);
2577 
2578 	return ret;
2579 }
2580 
2581 static int ohci_enable_phys_dma(struct fw_card *card,
2582 				int node_id, int generation)
2583 {
2584 	struct fw_ohci *ohci = fw_ohci(card);
2585 	unsigned long flags;
2586 	int n, ret = 0;
2587 
2588 	if (param_remote_dma)
2589 		return 0;
2590 
2591 	/*
2592 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2593 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2594 	 */
2595 
2596 	spin_lock_irqsave(&ohci->lock, flags);
2597 
2598 	if (ohci->generation != generation) {
2599 		ret = -ESTALE;
2600 		goto out;
2601 	}
2602 
2603 	/*
2604 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2605 	 * enabled for _all_ nodes on remote buses.
2606 	 */
2607 
2608 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2609 	if (n < 32)
2610 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2611 	else
2612 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2613 
2614 	flush_writes(ohci);
2615  out:
2616 	spin_unlock_irqrestore(&ohci->lock, flags);
2617 
2618 	return ret;
2619 }
2620 
2621 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2622 {
2623 	struct fw_ohci *ohci = fw_ohci(card);
2624 	unsigned long flags;
2625 	u32 value;
2626 
2627 	switch (csr_offset) {
2628 	case CSR_STATE_CLEAR:
2629 	case CSR_STATE_SET:
2630 		if (ohci->is_root &&
2631 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2632 		     OHCI1394_LinkControl_cycleMaster))
2633 			value = CSR_STATE_BIT_CMSTR;
2634 		else
2635 			value = 0;
2636 		if (ohci->csr_state_setclear_abdicate)
2637 			value |= CSR_STATE_BIT_ABDICATE;
2638 
2639 		return value;
2640 
2641 	case CSR_NODE_IDS:
2642 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2643 
2644 	case CSR_CYCLE_TIME:
2645 		return get_cycle_time(ohci);
2646 
2647 	case CSR_BUS_TIME:
2648 		/*
2649 		 * We might be called just after the cycle timer has wrapped
2650 		 * around but just before the cycle64Seconds handler, so we
2651 		 * better check here, too, if the bus time needs to be updated.
2652 		 */
2653 		spin_lock_irqsave(&ohci->lock, flags);
2654 		value = update_bus_time(ohci);
2655 		spin_unlock_irqrestore(&ohci->lock, flags);
2656 		return value;
2657 
2658 	case CSR_BUSY_TIMEOUT:
2659 		value = reg_read(ohci, OHCI1394_ATRetries);
2660 		return (value >> 4) & 0x0ffff00f;
2661 
2662 	case CSR_PRIORITY_BUDGET:
2663 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2664 			(ohci->pri_req_max << 8);
2665 
2666 	default:
2667 		WARN_ON(1);
2668 		return 0;
2669 	}
2670 }
2671 
2672 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2673 {
2674 	struct fw_ohci *ohci = fw_ohci(card);
2675 	unsigned long flags;
2676 
2677 	switch (csr_offset) {
2678 	case CSR_STATE_CLEAR:
2679 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2680 			reg_write(ohci, OHCI1394_LinkControlClear,
2681 				  OHCI1394_LinkControl_cycleMaster);
2682 			flush_writes(ohci);
2683 		}
2684 		if (value & CSR_STATE_BIT_ABDICATE)
2685 			ohci->csr_state_setclear_abdicate = false;
2686 		break;
2687 
2688 	case CSR_STATE_SET:
2689 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2690 			reg_write(ohci, OHCI1394_LinkControlSet,
2691 				  OHCI1394_LinkControl_cycleMaster);
2692 			flush_writes(ohci);
2693 		}
2694 		if (value & CSR_STATE_BIT_ABDICATE)
2695 			ohci->csr_state_setclear_abdicate = true;
2696 		break;
2697 
2698 	case CSR_NODE_IDS:
2699 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2700 		flush_writes(ohci);
2701 		break;
2702 
2703 	case CSR_CYCLE_TIME:
2704 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2705 		reg_write(ohci, OHCI1394_IntEventSet,
2706 			  OHCI1394_cycleInconsistent);
2707 		flush_writes(ohci);
2708 		break;
2709 
2710 	case CSR_BUS_TIME:
2711 		spin_lock_irqsave(&ohci->lock, flags);
2712 		ohci->bus_time = (update_bus_time(ohci) & 0x40) |
2713 		                 (value & ~0x7f);
2714 		spin_unlock_irqrestore(&ohci->lock, flags);
2715 		break;
2716 
2717 	case CSR_BUSY_TIMEOUT:
2718 		value = (value & 0xf) | ((value & 0xf) << 4) |
2719 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2720 		reg_write(ohci, OHCI1394_ATRetries, value);
2721 		flush_writes(ohci);
2722 		break;
2723 
2724 	case CSR_PRIORITY_BUDGET:
2725 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2726 		flush_writes(ohci);
2727 		break;
2728 
2729 	default:
2730 		WARN_ON(1);
2731 		break;
2732 	}
2733 }
2734 
2735 static void flush_iso_completions(struct iso_context *ctx)
2736 {
2737 	ctx->base.callback.sc(&ctx->base, ctx->last_timestamp,
2738 			      ctx->header_length, ctx->header,
2739 			      ctx->base.callback_data);
2740 	ctx->header_length = 0;
2741 }
2742 
2743 static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
2744 {
2745 	u32 *ctx_hdr;
2746 
2747 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
2748 		if (ctx->base.drop_overflow_headers)
2749 			return;
2750 		flush_iso_completions(ctx);
2751 	}
2752 
2753 	ctx_hdr = ctx->header + ctx->header_length;
2754 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
2755 
2756 	/*
2757 	 * The two iso header quadlets are byteswapped to little
2758 	 * endian by the controller, but we want to present them
2759 	 * as big endian for consistency with the bus endianness.
2760 	 */
2761 	if (ctx->base.header_size > 0)
2762 		ctx_hdr[0] = swab32(dma_hdr[1]); /* iso packet header */
2763 	if (ctx->base.header_size > 4)
2764 		ctx_hdr[1] = swab32(dma_hdr[0]); /* timestamp */
2765 	if (ctx->base.header_size > 8)
2766 		memcpy(&ctx_hdr[2], &dma_hdr[2], ctx->base.header_size - 8);
2767 	ctx->header_length += ctx->base.header_size;
2768 }
2769 
2770 static int handle_ir_packet_per_buffer(struct context *context,
2771 				       struct descriptor *d,
2772 				       struct descriptor *last)
2773 {
2774 	struct iso_context *ctx =
2775 		container_of(context, struct iso_context, context);
2776 	struct descriptor *pd;
2777 	u32 buffer_dma;
2778 
2779 	for (pd = d; pd <= last; pd++)
2780 		if (pd->transfer_status)
2781 			break;
2782 	if (pd > last)
2783 		/* Descriptor(s) not done yet, stop iteration */
2784 		return 0;
2785 
2786 	while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
2787 		d++;
2788 		buffer_dma = le32_to_cpu(d->data_address);
2789 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2790 					      buffer_dma & PAGE_MASK,
2791 					      buffer_dma & ~PAGE_MASK,
2792 					      le16_to_cpu(d->req_count),
2793 					      DMA_FROM_DEVICE);
2794 	}
2795 
2796 	copy_iso_headers(ctx, (u32 *) (last + 1));
2797 
2798 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2799 		flush_iso_completions(ctx);
2800 
2801 	return 1;
2802 }
2803 
2804 /* d == last because each descriptor block is only a single descriptor. */
2805 static int handle_ir_buffer_fill(struct context *context,
2806 				 struct descriptor *d,
2807 				 struct descriptor *last)
2808 {
2809 	struct iso_context *ctx =
2810 		container_of(context, struct iso_context, context);
2811 	unsigned int req_count, res_count, completed;
2812 	u32 buffer_dma;
2813 
2814 	req_count = le16_to_cpu(last->req_count);
2815 	res_count = le16_to_cpu(ACCESS_ONCE(last->res_count));
2816 	completed = req_count - res_count;
2817 	buffer_dma = le32_to_cpu(last->data_address);
2818 
2819 	if (completed > 0) {
2820 		ctx->mc_buffer_bus = buffer_dma;
2821 		ctx->mc_completed = completed;
2822 	}
2823 
2824 	if (res_count != 0)
2825 		/* Descriptor(s) not done yet, stop iteration */
2826 		return 0;
2827 
2828 	dma_sync_single_range_for_cpu(context->ohci->card.device,
2829 				      buffer_dma & PAGE_MASK,
2830 				      buffer_dma & ~PAGE_MASK,
2831 				      completed, DMA_FROM_DEVICE);
2832 
2833 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) {
2834 		ctx->base.callback.mc(&ctx->base,
2835 				      buffer_dma + completed,
2836 				      ctx->base.callback_data);
2837 		ctx->mc_completed = 0;
2838 	}
2839 
2840 	return 1;
2841 }
2842 
2843 static void flush_ir_buffer_fill(struct iso_context *ctx)
2844 {
2845 	dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
2846 				      ctx->mc_buffer_bus & PAGE_MASK,
2847 				      ctx->mc_buffer_bus & ~PAGE_MASK,
2848 				      ctx->mc_completed, DMA_FROM_DEVICE);
2849 
2850 	ctx->base.callback.mc(&ctx->base,
2851 			      ctx->mc_buffer_bus + ctx->mc_completed,
2852 			      ctx->base.callback_data);
2853 	ctx->mc_completed = 0;
2854 }
2855 
2856 static inline void sync_it_packet_for_cpu(struct context *context,
2857 					  struct descriptor *pd)
2858 {
2859 	__le16 control;
2860 	u32 buffer_dma;
2861 
2862 	/* only packets beginning with OUTPUT_MORE* have data buffers */
2863 	if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2864 		return;
2865 
2866 	/* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
2867 	pd += 2;
2868 
2869 	/*
2870 	 * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
2871 	 * data buffer is in the context program's coherent page and must not
2872 	 * be synced.
2873 	 */
2874 	if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
2875 	    (context->current_bus          & PAGE_MASK)) {
2876 		if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2877 			return;
2878 		pd++;
2879 	}
2880 
2881 	do {
2882 		buffer_dma = le32_to_cpu(pd->data_address);
2883 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2884 					      buffer_dma & PAGE_MASK,
2885 					      buffer_dma & ~PAGE_MASK,
2886 					      le16_to_cpu(pd->req_count),
2887 					      DMA_TO_DEVICE);
2888 		control = pd->control;
2889 		pd++;
2890 	} while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
2891 }
2892 
2893 static int handle_it_packet(struct context *context,
2894 			    struct descriptor *d,
2895 			    struct descriptor *last)
2896 {
2897 	struct iso_context *ctx =
2898 		container_of(context, struct iso_context, context);
2899 	struct descriptor *pd;
2900 	__be32 *ctx_hdr;
2901 
2902 	for (pd = d; pd <= last; pd++)
2903 		if (pd->transfer_status)
2904 			break;
2905 	if (pd > last)
2906 		/* Descriptor(s) not done yet, stop iteration */
2907 		return 0;
2908 
2909 	sync_it_packet_for_cpu(context, d);
2910 
2911 	if (ctx->header_length + 4 > PAGE_SIZE) {
2912 		if (ctx->base.drop_overflow_headers)
2913 			return 1;
2914 		flush_iso_completions(ctx);
2915 	}
2916 
2917 	ctx_hdr = ctx->header + ctx->header_length;
2918 	ctx->last_timestamp = le16_to_cpu(last->res_count);
2919 	/* Present this value as big-endian to match the receive code */
2920 	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
2921 			       le16_to_cpu(pd->res_count));
2922 	ctx->header_length += 4;
2923 
2924 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2925 		flush_iso_completions(ctx);
2926 
2927 	return 1;
2928 }
2929 
2930 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2931 {
2932 	u32 hi = channels >> 32, lo = channels;
2933 
2934 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2935 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2936 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2937 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2938 	mmiowb();
2939 	ohci->mc_channels = channels;
2940 }
2941 
2942 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2943 				int type, int channel, size_t header_size)
2944 {
2945 	struct fw_ohci *ohci = fw_ohci(card);
2946 	struct iso_context *uninitialized_var(ctx);
2947 	descriptor_callback_t uninitialized_var(callback);
2948 	u64 *uninitialized_var(channels);
2949 	u32 *uninitialized_var(mask), uninitialized_var(regs);
2950 	int index, ret = -EBUSY;
2951 
2952 	spin_lock_irq(&ohci->lock);
2953 
2954 	switch (type) {
2955 	case FW_ISO_CONTEXT_TRANSMIT:
2956 		mask     = &ohci->it_context_mask;
2957 		callback = handle_it_packet;
2958 		index    = ffs(*mask) - 1;
2959 		if (index >= 0) {
2960 			*mask &= ~(1 << index);
2961 			regs = OHCI1394_IsoXmitContextBase(index);
2962 			ctx  = &ohci->it_context_list[index];
2963 		}
2964 		break;
2965 
2966 	case FW_ISO_CONTEXT_RECEIVE:
2967 		channels = &ohci->ir_context_channels;
2968 		mask     = &ohci->ir_context_mask;
2969 		callback = handle_ir_packet_per_buffer;
2970 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2971 		if (index >= 0) {
2972 			*channels &= ~(1ULL << channel);
2973 			*mask     &= ~(1 << index);
2974 			regs = OHCI1394_IsoRcvContextBase(index);
2975 			ctx  = &ohci->ir_context_list[index];
2976 		}
2977 		break;
2978 
2979 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2980 		mask     = &ohci->ir_context_mask;
2981 		callback = handle_ir_buffer_fill;
2982 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2983 		if (index >= 0) {
2984 			ohci->mc_allocated = true;
2985 			*mask &= ~(1 << index);
2986 			regs = OHCI1394_IsoRcvContextBase(index);
2987 			ctx  = &ohci->ir_context_list[index];
2988 		}
2989 		break;
2990 
2991 	default:
2992 		index = -1;
2993 		ret = -ENOSYS;
2994 	}
2995 
2996 	spin_unlock_irq(&ohci->lock);
2997 
2998 	if (index < 0)
2999 		return ERR_PTR(ret);
3000 
3001 	memset(ctx, 0, sizeof(*ctx));
3002 	ctx->header_length = 0;
3003 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
3004 	if (ctx->header == NULL) {
3005 		ret = -ENOMEM;
3006 		goto out;
3007 	}
3008 	ret = context_init(&ctx->context, ohci, regs, callback);
3009 	if (ret < 0)
3010 		goto out_with_header;
3011 
3012 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
3013 		set_multichannel_mask(ohci, 0);
3014 		ctx->mc_completed = 0;
3015 	}
3016 
3017 	return &ctx->base;
3018 
3019  out_with_header:
3020 	free_page((unsigned long)ctx->header);
3021  out:
3022 	spin_lock_irq(&ohci->lock);
3023 
3024 	switch (type) {
3025 	case FW_ISO_CONTEXT_RECEIVE:
3026 		*channels |= 1ULL << channel;
3027 		break;
3028 
3029 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3030 		ohci->mc_allocated = false;
3031 		break;
3032 	}
3033 	*mask |= 1 << index;
3034 
3035 	spin_unlock_irq(&ohci->lock);
3036 
3037 	return ERR_PTR(ret);
3038 }
3039 
3040 static int ohci_start_iso(struct fw_iso_context *base,
3041 			  s32 cycle, u32 sync, u32 tags)
3042 {
3043 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3044 	struct fw_ohci *ohci = ctx->context.ohci;
3045 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
3046 	int index;
3047 
3048 	/* the controller cannot start without any queued packets */
3049 	if (ctx->context.last->branch_address == 0)
3050 		return -ENODATA;
3051 
3052 	switch (ctx->base.type) {
3053 	case FW_ISO_CONTEXT_TRANSMIT:
3054 		index = ctx - ohci->it_context_list;
3055 		match = 0;
3056 		if (cycle >= 0)
3057 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
3058 				(cycle & 0x7fff) << 16;
3059 
3060 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
3061 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
3062 		context_run(&ctx->context, match);
3063 		break;
3064 
3065 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3066 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
3067 		/* fall through */
3068 	case FW_ISO_CONTEXT_RECEIVE:
3069 		index = ctx - ohci->ir_context_list;
3070 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
3071 		if (cycle >= 0) {
3072 			match |= (cycle & 0x07fff) << 12;
3073 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
3074 		}
3075 
3076 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
3077 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
3078 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
3079 		context_run(&ctx->context, control);
3080 
3081 		ctx->sync = sync;
3082 		ctx->tags = tags;
3083 
3084 		break;
3085 	}
3086 
3087 	return 0;
3088 }
3089 
3090 static int ohci_stop_iso(struct fw_iso_context *base)
3091 {
3092 	struct fw_ohci *ohci = fw_ohci(base->card);
3093 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3094 	int index;
3095 
3096 	switch (ctx->base.type) {
3097 	case FW_ISO_CONTEXT_TRANSMIT:
3098 		index = ctx - ohci->it_context_list;
3099 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
3100 		break;
3101 
3102 	case FW_ISO_CONTEXT_RECEIVE:
3103 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3104 		index = ctx - ohci->ir_context_list;
3105 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
3106 		break;
3107 	}
3108 	flush_writes(ohci);
3109 	context_stop(&ctx->context);
3110 	tasklet_kill(&ctx->context.tasklet);
3111 
3112 	return 0;
3113 }
3114 
3115 static void ohci_free_iso_context(struct fw_iso_context *base)
3116 {
3117 	struct fw_ohci *ohci = fw_ohci(base->card);
3118 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3119 	unsigned long flags;
3120 	int index;
3121 
3122 	ohci_stop_iso(base);
3123 	context_release(&ctx->context);
3124 	free_page((unsigned long)ctx->header);
3125 
3126 	spin_lock_irqsave(&ohci->lock, flags);
3127 
3128 	switch (base->type) {
3129 	case FW_ISO_CONTEXT_TRANSMIT:
3130 		index = ctx - ohci->it_context_list;
3131 		ohci->it_context_mask |= 1 << index;
3132 		break;
3133 
3134 	case FW_ISO_CONTEXT_RECEIVE:
3135 		index = ctx - ohci->ir_context_list;
3136 		ohci->ir_context_mask |= 1 << index;
3137 		ohci->ir_context_channels |= 1ULL << base->channel;
3138 		break;
3139 
3140 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3141 		index = ctx - ohci->ir_context_list;
3142 		ohci->ir_context_mask |= 1 << index;
3143 		ohci->ir_context_channels |= ohci->mc_channels;
3144 		ohci->mc_channels = 0;
3145 		ohci->mc_allocated = false;
3146 		break;
3147 	}
3148 
3149 	spin_unlock_irqrestore(&ohci->lock, flags);
3150 }
3151 
3152 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
3153 {
3154 	struct fw_ohci *ohci = fw_ohci(base->card);
3155 	unsigned long flags;
3156 	int ret;
3157 
3158 	switch (base->type) {
3159 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3160 
3161 		spin_lock_irqsave(&ohci->lock, flags);
3162 
3163 		/* Don't allow multichannel to grab other contexts' channels. */
3164 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
3165 			*channels = ohci->ir_context_channels;
3166 			ret = -EBUSY;
3167 		} else {
3168 			set_multichannel_mask(ohci, *channels);
3169 			ret = 0;
3170 		}
3171 
3172 		spin_unlock_irqrestore(&ohci->lock, flags);
3173 
3174 		break;
3175 	default:
3176 		ret = -EINVAL;
3177 	}
3178 
3179 	return ret;
3180 }
3181 
3182 #ifdef CONFIG_PM
3183 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
3184 {
3185 	int i;
3186 	struct iso_context *ctx;
3187 
3188 	for (i = 0 ; i < ohci->n_ir ; i++) {
3189 		ctx = &ohci->ir_context_list[i];
3190 		if (ctx->context.running)
3191 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3192 	}
3193 
3194 	for (i = 0 ; i < ohci->n_it ; i++) {
3195 		ctx = &ohci->it_context_list[i];
3196 		if (ctx->context.running)
3197 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3198 	}
3199 }
3200 #endif
3201 
3202 static int queue_iso_transmit(struct iso_context *ctx,
3203 			      struct fw_iso_packet *packet,
3204 			      struct fw_iso_buffer *buffer,
3205 			      unsigned long payload)
3206 {
3207 	struct descriptor *d, *last, *pd;
3208 	struct fw_iso_packet *p;
3209 	__le32 *header;
3210 	dma_addr_t d_bus, page_bus;
3211 	u32 z, header_z, payload_z, irq;
3212 	u32 payload_index, payload_end_index, next_page_index;
3213 	int page, end_page, i, length, offset;
3214 
3215 	p = packet;
3216 	payload_index = payload;
3217 
3218 	if (p->skip)
3219 		z = 1;
3220 	else
3221 		z = 2;
3222 	if (p->header_length > 0)
3223 		z++;
3224 
3225 	/* Determine the first page the payload isn't contained in. */
3226 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
3227 	if (p->payload_length > 0)
3228 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
3229 	else
3230 		payload_z = 0;
3231 
3232 	z += payload_z;
3233 
3234 	/* Get header size in number of descriptors. */
3235 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
3236 
3237 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
3238 	if (d == NULL)
3239 		return -ENOMEM;
3240 
3241 	if (!p->skip) {
3242 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
3243 		d[0].req_count = cpu_to_le16(8);
3244 		/*
3245 		 * Link the skip address to this descriptor itself.  This causes
3246 		 * a context to skip a cycle whenever lost cycles or FIFO
3247 		 * overruns occur, without dropping the data.  The application
3248 		 * should then decide whether this is an error condition or not.
3249 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
3250 		 */
3251 		d[0].branch_address = cpu_to_le32(d_bus | z);
3252 
3253 		header = (__le32 *) &d[1];
3254 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
3255 					IT_HEADER_TAG(p->tag) |
3256 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
3257 					IT_HEADER_CHANNEL(ctx->base.channel) |
3258 					IT_HEADER_SPEED(ctx->base.speed));
3259 		header[1] =
3260 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
3261 							  p->payload_length));
3262 	}
3263 
3264 	if (p->header_length > 0) {
3265 		d[2].req_count    = cpu_to_le16(p->header_length);
3266 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
3267 		memcpy(&d[z], p->header, p->header_length);
3268 	}
3269 
3270 	pd = d + z - payload_z;
3271 	payload_end_index = payload_index + p->payload_length;
3272 	for (i = 0; i < payload_z; i++) {
3273 		page               = payload_index >> PAGE_SHIFT;
3274 		offset             = payload_index & ~PAGE_MASK;
3275 		next_page_index    = (page + 1) << PAGE_SHIFT;
3276 		length             =
3277 			min(next_page_index, payload_end_index) - payload_index;
3278 		pd[i].req_count    = cpu_to_le16(length);
3279 
3280 		page_bus = page_private(buffer->pages[page]);
3281 		pd[i].data_address = cpu_to_le32(page_bus + offset);
3282 
3283 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3284 						 page_bus, offset, length,
3285 						 DMA_TO_DEVICE);
3286 
3287 		payload_index += length;
3288 	}
3289 
3290 	if (p->interrupt)
3291 		irq = DESCRIPTOR_IRQ_ALWAYS;
3292 	else
3293 		irq = DESCRIPTOR_NO_IRQ;
3294 
3295 	last = z == 2 ? d : d + z - 1;
3296 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
3297 				     DESCRIPTOR_STATUS |
3298 				     DESCRIPTOR_BRANCH_ALWAYS |
3299 				     irq);
3300 
3301 	context_append(&ctx->context, d, z, header_z);
3302 
3303 	return 0;
3304 }
3305 
3306 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
3307 				       struct fw_iso_packet *packet,
3308 				       struct fw_iso_buffer *buffer,
3309 				       unsigned long payload)
3310 {
3311 	struct device *device = ctx->context.ohci->card.device;
3312 	struct descriptor *d, *pd;
3313 	dma_addr_t d_bus, page_bus;
3314 	u32 z, header_z, rest;
3315 	int i, j, length;
3316 	int page, offset, packet_count, header_size, payload_per_buffer;
3317 
3318 	/*
3319 	 * The OHCI controller puts the isochronous header and trailer in the
3320 	 * buffer, so we need at least 8 bytes.
3321 	 */
3322 	packet_count = packet->header_length / ctx->base.header_size;
3323 	header_size  = max(ctx->base.header_size, (size_t)8);
3324 
3325 	/* Get header size in number of descriptors. */
3326 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
3327 	page     = payload >> PAGE_SHIFT;
3328 	offset   = payload & ~PAGE_MASK;
3329 	payload_per_buffer = packet->payload_length / packet_count;
3330 
3331 	for (i = 0; i < packet_count; i++) {
3332 		/* d points to the header descriptor */
3333 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
3334 		d = context_get_descriptors(&ctx->context,
3335 				z + header_z, &d_bus);
3336 		if (d == NULL)
3337 			return -ENOMEM;
3338 
3339 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3340 					      DESCRIPTOR_INPUT_MORE);
3341 		if (packet->skip && i == 0)
3342 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3343 		d->req_count    = cpu_to_le16(header_size);
3344 		d->res_count    = d->req_count;
3345 		d->transfer_status = 0;
3346 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3347 
3348 		rest = payload_per_buffer;
3349 		pd = d;
3350 		for (j = 1; j < z; j++) {
3351 			pd++;
3352 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3353 						  DESCRIPTOR_INPUT_MORE);
3354 
3355 			if (offset + rest < PAGE_SIZE)
3356 				length = rest;
3357 			else
3358 				length = PAGE_SIZE - offset;
3359 			pd->req_count = cpu_to_le16(length);
3360 			pd->res_count = pd->req_count;
3361 			pd->transfer_status = 0;
3362 
3363 			page_bus = page_private(buffer->pages[page]);
3364 			pd->data_address = cpu_to_le32(page_bus + offset);
3365 
3366 			dma_sync_single_range_for_device(device, page_bus,
3367 							 offset, length,
3368 							 DMA_FROM_DEVICE);
3369 
3370 			offset = (offset + length) & ~PAGE_MASK;
3371 			rest -= length;
3372 			if (offset == 0)
3373 				page++;
3374 		}
3375 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3376 					  DESCRIPTOR_INPUT_LAST |
3377 					  DESCRIPTOR_BRANCH_ALWAYS);
3378 		if (packet->interrupt && i == packet_count - 1)
3379 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3380 
3381 		context_append(&ctx->context, d, z, header_z);
3382 	}
3383 
3384 	return 0;
3385 }
3386 
3387 static int queue_iso_buffer_fill(struct iso_context *ctx,
3388 				 struct fw_iso_packet *packet,
3389 				 struct fw_iso_buffer *buffer,
3390 				 unsigned long payload)
3391 {
3392 	struct descriptor *d;
3393 	dma_addr_t d_bus, page_bus;
3394 	int page, offset, rest, z, i, length;
3395 
3396 	page   = payload >> PAGE_SHIFT;
3397 	offset = payload & ~PAGE_MASK;
3398 	rest   = packet->payload_length;
3399 
3400 	/* We need one descriptor for each page in the buffer. */
3401 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3402 
3403 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3404 		return -EFAULT;
3405 
3406 	for (i = 0; i < z; i++) {
3407 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3408 		if (d == NULL)
3409 			return -ENOMEM;
3410 
3411 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3412 					 DESCRIPTOR_BRANCH_ALWAYS);
3413 		if (packet->skip && i == 0)
3414 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3415 		if (packet->interrupt && i == z - 1)
3416 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3417 
3418 		if (offset + rest < PAGE_SIZE)
3419 			length = rest;
3420 		else
3421 			length = PAGE_SIZE - offset;
3422 		d->req_count = cpu_to_le16(length);
3423 		d->res_count = d->req_count;
3424 		d->transfer_status = 0;
3425 
3426 		page_bus = page_private(buffer->pages[page]);
3427 		d->data_address = cpu_to_le32(page_bus + offset);
3428 
3429 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3430 						 page_bus, offset, length,
3431 						 DMA_FROM_DEVICE);
3432 
3433 		rest -= length;
3434 		offset = 0;
3435 		page++;
3436 
3437 		context_append(&ctx->context, d, 1, 0);
3438 	}
3439 
3440 	return 0;
3441 }
3442 
3443 static int ohci_queue_iso(struct fw_iso_context *base,
3444 			  struct fw_iso_packet *packet,
3445 			  struct fw_iso_buffer *buffer,
3446 			  unsigned long payload)
3447 {
3448 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3449 	unsigned long flags;
3450 	int ret = -ENOSYS;
3451 
3452 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3453 	switch (base->type) {
3454 	case FW_ISO_CONTEXT_TRANSMIT:
3455 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3456 		break;
3457 	case FW_ISO_CONTEXT_RECEIVE:
3458 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3459 		break;
3460 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3461 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3462 		break;
3463 	}
3464 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3465 
3466 	return ret;
3467 }
3468 
3469 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3470 {
3471 	struct context *ctx =
3472 			&container_of(base, struct iso_context, base)->context;
3473 
3474 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3475 }
3476 
3477 static int ohci_flush_iso_completions(struct fw_iso_context *base)
3478 {
3479 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3480 	int ret = 0;
3481 
3482 	tasklet_disable(&ctx->context.tasklet);
3483 
3484 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
3485 		context_tasklet((unsigned long)&ctx->context);
3486 
3487 		switch (base->type) {
3488 		case FW_ISO_CONTEXT_TRANSMIT:
3489 		case FW_ISO_CONTEXT_RECEIVE:
3490 			if (ctx->header_length != 0)
3491 				flush_iso_completions(ctx);
3492 			break;
3493 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3494 			if (ctx->mc_completed != 0)
3495 				flush_ir_buffer_fill(ctx);
3496 			break;
3497 		default:
3498 			ret = -ENOSYS;
3499 		}
3500 
3501 		clear_bit_unlock(0, &ctx->flushing_completions);
3502 		smp_mb__after_atomic();
3503 	}
3504 
3505 	tasklet_enable(&ctx->context.tasklet);
3506 
3507 	return ret;
3508 }
3509 
3510 static const struct fw_card_driver ohci_driver = {
3511 	.enable			= ohci_enable,
3512 	.read_phy_reg		= ohci_read_phy_reg,
3513 	.update_phy_reg		= ohci_update_phy_reg,
3514 	.set_config_rom		= ohci_set_config_rom,
3515 	.send_request		= ohci_send_request,
3516 	.send_response		= ohci_send_response,
3517 	.cancel_packet		= ohci_cancel_packet,
3518 	.enable_phys_dma	= ohci_enable_phys_dma,
3519 	.read_csr		= ohci_read_csr,
3520 	.write_csr		= ohci_write_csr,
3521 
3522 	.allocate_iso_context	= ohci_allocate_iso_context,
3523 	.free_iso_context	= ohci_free_iso_context,
3524 	.set_iso_channels	= ohci_set_iso_channels,
3525 	.queue_iso		= ohci_queue_iso,
3526 	.flush_queue_iso	= ohci_flush_queue_iso,
3527 	.flush_iso_completions	= ohci_flush_iso_completions,
3528 	.start_iso		= ohci_start_iso,
3529 	.stop_iso		= ohci_stop_iso,
3530 };
3531 
3532 #ifdef CONFIG_PPC_PMAC
3533 static void pmac_ohci_on(struct pci_dev *dev)
3534 {
3535 	if (machine_is(powermac)) {
3536 		struct device_node *ofn = pci_device_to_OF_node(dev);
3537 
3538 		if (ofn) {
3539 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3540 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3541 		}
3542 	}
3543 }
3544 
3545 static void pmac_ohci_off(struct pci_dev *dev)
3546 {
3547 	if (machine_is(powermac)) {
3548 		struct device_node *ofn = pci_device_to_OF_node(dev);
3549 
3550 		if (ofn) {
3551 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3552 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3553 		}
3554 	}
3555 }
3556 #else
3557 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3558 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3559 #endif /* CONFIG_PPC_PMAC */
3560 
3561 static int pci_probe(struct pci_dev *dev,
3562 			       const struct pci_device_id *ent)
3563 {
3564 	struct fw_ohci *ohci;
3565 	u32 bus_options, max_receive, link_speed, version;
3566 	u64 guid;
3567 	int i, err;
3568 	size_t size;
3569 
3570 	if (dev->vendor == PCI_VENDOR_ID_PINNACLE_SYSTEMS) {
3571 		dev_err(&dev->dev, "Pinnacle MovieBoard is not yet supported\n");
3572 		return -ENOSYS;
3573 	}
3574 
3575 	ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3576 	if (ohci == NULL) {
3577 		err = -ENOMEM;
3578 		goto fail;
3579 	}
3580 
3581 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3582 
3583 	pmac_ohci_on(dev);
3584 
3585 	err = pci_enable_device(dev);
3586 	if (err) {
3587 		dev_err(&dev->dev, "failed to enable OHCI hardware\n");
3588 		goto fail_free;
3589 	}
3590 
3591 	pci_set_master(dev);
3592 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3593 	pci_set_drvdata(dev, ohci);
3594 
3595 	spin_lock_init(&ohci->lock);
3596 	mutex_init(&ohci->phy_reg_mutex);
3597 
3598 	INIT_WORK(&ohci->bus_reset_work, bus_reset_work);
3599 
3600 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM) ||
3601 	    pci_resource_len(dev, 0) < OHCI1394_REGISTER_SIZE) {
3602 		ohci_err(ohci, "invalid MMIO resource\n");
3603 		err = -ENXIO;
3604 		goto fail_disable;
3605 	}
3606 
3607 	err = pci_request_region(dev, 0, ohci_driver_name);
3608 	if (err) {
3609 		ohci_err(ohci, "MMIO resource unavailable\n");
3610 		goto fail_disable;
3611 	}
3612 
3613 	ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3614 	if (ohci->registers == NULL) {
3615 		ohci_err(ohci, "failed to remap registers\n");
3616 		err = -ENXIO;
3617 		goto fail_iomem;
3618 	}
3619 
3620 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3621 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3622 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3623 		     ohci_quirks[i].device == dev->device) &&
3624 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3625 		     ohci_quirks[i].revision >= dev->revision)) {
3626 			ohci->quirks = ohci_quirks[i].flags;
3627 			break;
3628 		}
3629 	if (param_quirks)
3630 		ohci->quirks = param_quirks;
3631 
3632 	/*
3633 	 * Because dma_alloc_coherent() allocates at least one page,
3634 	 * we save space by using a common buffer for the AR request/
3635 	 * response descriptors and the self IDs buffer.
3636 	 */
3637 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3638 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3639 	ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3640 					       PAGE_SIZE,
3641 					       &ohci->misc_buffer_bus,
3642 					       GFP_KERNEL);
3643 	if (!ohci->misc_buffer) {
3644 		err = -ENOMEM;
3645 		goto fail_iounmap;
3646 	}
3647 
3648 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3649 			      OHCI1394_AsReqRcvContextControlSet);
3650 	if (err < 0)
3651 		goto fail_misc_buf;
3652 
3653 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3654 			      OHCI1394_AsRspRcvContextControlSet);
3655 	if (err < 0)
3656 		goto fail_arreq_ctx;
3657 
3658 	err = context_init(&ohci->at_request_ctx, ohci,
3659 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3660 	if (err < 0)
3661 		goto fail_arrsp_ctx;
3662 
3663 	err = context_init(&ohci->at_response_ctx, ohci,
3664 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3665 	if (err < 0)
3666 		goto fail_atreq_ctx;
3667 
3668 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3669 	ohci->ir_context_channels = ~0ULL;
3670 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3671 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3672 	ohci->ir_context_mask = ohci->ir_context_support;
3673 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3674 	size = sizeof(struct iso_context) * ohci->n_ir;
3675 	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3676 
3677 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3678 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3679 	/* JMicron JMB38x often shows 0 at first read, just ignore it */
3680 	if (!ohci->it_context_support) {
3681 		ohci_notice(ohci, "overriding IsoXmitIntMask\n");
3682 		ohci->it_context_support = 0xf;
3683 	}
3684 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3685 	ohci->it_context_mask = ohci->it_context_support;
3686 	ohci->n_it = hweight32(ohci->it_context_mask);
3687 	size = sizeof(struct iso_context) * ohci->n_it;
3688 	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3689 
3690 	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3691 		err = -ENOMEM;
3692 		goto fail_contexts;
3693 	}
3694 
3695 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
3696 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3697 
3698 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3699 	max_receive = (bus_options >> 12) & 0xf;
3700 	link_speed = bus_options & 0x7;
3701 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3702 		reg_read(ohci, OHCI1394_GUIDLo);
3703 
3704 	if (!(ohci->quirks & QUIRK_NO_MSI))
3705 		pci_enable_msi(dev);
3706 	if (request_irq(dev->irq, irq_handler,
3707 			pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
3708 			ohci_driver_name, ohci)) {
3709 		ohci_err(ohci, "failed to allocate interrupt %d\n", dev->irq);
3710 		err = -EIO;
3711 		goto fail_msi;
3712 	}
3713 
3714 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3715 	if (err)
3716 		goto fail_irq;
3717 
3718 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3719 	ohci_notice(ohci,
3720 		    "added OHCI v%x.%x device as card %d, "
3721 		    "%d IR + %d IT contexts, quirks 0x%x%s\n",
3722 		    version >> 16, version & 0xff, ohci->card.index,
3723 		    ohci->n_ir, ohci->n_it, ohci->quirks,
3724 		    reg_read(ohci, OHCI1394_PhyUpperBound) ?
3725 			", physUB" : "");
3726 
3727 	return 0;
3728 
3729  fail_irq:
3730 	free_irq(dev->irq, ohci);
3731  fail_msi:
3732 	pci_disable_msi(dev);
3733  fail_contexts:
3734 	kfree(ohci->ir_context_list);
3735 	kfree(ohci->it_context_list);
3736 	context_release(&ohci->at_response_ctx);
3737  fail_atreq_ctx:
3738 	context_release(&ohci->at_request_ctx);
3739  fail_arrsp_ctx:
3740 	ar_context_release(&ohci->ar_response_ctx);
3741  fail_arreq_ctx:
3742 	ar_context_release(&ohci->ar_request_ctx);
3743  fail_misc_buf:
3744 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3745 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3746  fail_iounmap:
3747 	pci_iounmap(dev, ohci->registers);
3748  fail_iomem:
3749 	pci_release_region(dev, 0);
3750  fail_disable:
3751 	pci_disable_device(dev);
3752  fail_free:
3753 	kfree(ohci);
3754 	pmac_ohci_off(dev);
3755  fail:
3756 	return err;
3757 }
3758 
3759 static void pci_remove(struct pci_dev *dev)
3760 {
3761 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3762 
3763 	/*
3764 	 * If the removal is happening from the suspend state, LPS won't be
3765 	 * enabled and host registers (eg., IntMaskClear) won't be accessible.
3766 	 */
3767 	if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) {
3768 		reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3769 		flush_writes(ohci);
3770 	}
3771 	cancel_work_sync(&ohci->bus_reset_work);
3772 	fw_core_remove_card(&ohci->card);
3773 
3774 	/*
3775 	 * FIXME: Fail all pending packets here, now that the upper
3776 	 * layers can't queue any more.
3777 	 */
3778 
3779 	software_reset(ohci);
3780 	free_irq(dev->irq, ohci);
3781 
3782 	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3783 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3784 				  ohci->next_config_rom, ohci->next_config_rom_bus);
3785 	if (ohci->config_rom)
3786 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3787 				  ohci->config_rom, ohci->config_rom_bus);
3788 	ar_context_release(&ohci->ar_request_ctx);
3789 	ar_context_release(&ohci->ar_response_ctx);
3790 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3791 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3792 	context_release(&ohci->at_request_ctx);
3793 	context_release(&ohci->at_response_ctx);
3794 	kfree(ohci->it_context_list);
3795 	kfree(ohci->ir_context_list);
3796 	pci_disable_msi(dev);
3797 	pci_iounmap(dev, ohci->registers);
3798 	pci_release_region(dev, 0);
3799 	pci_disable_device(dev);
3800 	kfree(ohci);
3801 	pmac_ohci_off(dev);
3802 
3803 	dev_notice(&dev->dev, "removed fw-ohci device\n");
3804 }
3805 
3806 #ifdef CONFIG_PM
3807 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3808 {
3809 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3810 	int err;
3811 
3812 	software_reset(ohci);
3813 	err = pci_save_state(dev);
3814 	if (err) {
3815 		ohci_err(ohci, "pci_save_state failed\n");
3816 		return err;
3817 	}
3818 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3819 	if (err)
3820 		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
3821 	pmac_ohci_off(dev);
3822 
3823 	return 0;
3824 }
3825 
3826 static int pci_resume(struct pci_dev *dev)
3827 {
3828 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3829 	int err;
3830 
3831 	pmac_ohci_on(dev);
3832 	pci_set_power_state(dev, PCI_D0);
3833 	pci_restore_state(dev);
3834 	err = pci_enable_device(dev);
3835 	if (err) {
3836 		ohci_err(ohci, "pci_enable_device failed\n");
3837 		return err;
3838 	}
3839 
3840 	/* Some systems don't setup GUID register on resume from ram  */
3841 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3842 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3843 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3844 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3845 	}
3846 
3847 	err = ohci_enable(&ohci->card, NULL, 0);
3848 	if (err)
3849 		return err;
3850 
3851 	ohci_resume_iso_dma(ohci);
3852 
3853 	return 0;
3854 }
3855 #endif
3856 
3857 static const struct pci_device_id pci_table[] = {
3858 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3859 	{ }
3860 };
3861 
3862 MODULE_DEVICE_TABLE(pci, pci_table);
3863 
3864 static struct pci_driver fw_ohci_pci_driver = {
3865 	.name		= ohci_driver_name,
3866 	.id_table	= pci_table,
3867 	.probe		= pci_probe,
3868 	.remove		= pci_remove,
3869 #ifdef CONFIG_PM
3870 	.resume		= pci_resume,
3871 	.suspend	= pci_suspend,
3872 #endif
3873 };
3874 
3875 static int __init fw_ohci_init(void)
3876 {
3877 	selfid_workqueue = alloc_workqueue(KBUILD_MODNAME, WQ_MEM_RECLAIM, 0);
3878 	if (!selfid_workqueue)
3879 		return -ENOMEM;
3880 
3881 	return pci_register_driver(&fw_ohci_pci_driver);
3882 }
3883 
3884 static void __exit fw_ohci_cleanup(void)
3885 {
3886 	pci_unregister_driver(&fw_ohci_pci_driver);
3887 	destroy_workqueue(selfid_workqueue);
3888 }
3889 
3890 module_init(fw_ohci_init);
3891 module_exit(fw_ohci_cleanup);
3892 
3893 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3894 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3895 MODULE_LICENSE("GPL");
3896 
3897 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3898 MODULE_ALIAS("ohci1394");
3899