xref: /linux/drivers/firewire/ohci.c (revision 12871a0bd67dd4db4418e1daafcd46e9d329ef10)
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 
46 #include <asm/byteorder.h>
47 #include <asm/page.h>
48 #include <asm/system.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 DESCRIPTOR_OUTPUT_MORE		0
58 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
59 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
60 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
61 #define DESCRIPTOR_STATUS		(1 << 11)
62 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
63 #define DESCRIPTOR_PING			(1 << 7)
64 #define DESCRIPTOR_YY			(1 << 6)
65 #define DESCRIPTOR_NO_IRQ		(0 << 4)
66 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
67 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
68 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
69 #define DESCRIPTOR_WAIT			(3 << 0)
70 
71 struct descriptor {
72 	__le16 req_count;
73 	__le16 control;
74 	__le32 data_address;
75 	__le32 branch_address;
76 	__le16 res_count;
77 	__le16 transfer_status;
78 } __attribute__((aligned(16)));
79 
80 #define CONTROL_SET(regs)	(regs)
81 #define CONTROL_CLEAR(regs)	((regs) + 4)
82 #define COMMAND_PTR(regs)	((regs) + 12)
83 #define CONTEXT_MATCH(regs)	((regs) + 16)
84 
85 #define AR_BUFFER_SIZE	(32*1024)
86 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
87 /* we need at least two pages for proper list management */
88 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
89 
90 #define MAX_ASYNC_PAYLOAD	4096
91 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
92 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
93 
94 struct ar_context {
95 	struct fw_ohci *ohci;
96 	struct page *pages[AR_BUFFERS];
97 	void *buffer;
98 	struct descriptor *descriptors;
99 	dma_addr_t descriptors_bus;
100 	void *pointer;
101 	unsigned int last_buffer_index;
102 	u32 regs;
103 	struct tasklet_struct tasklet;
104 };
105 
106 struct context;
107 
108 typedef int (*descriptor_callback_t)(struct context *ctx,
109 				     struct descriptor *d,
110 				     struct descriptor *last);
111 
112 /*
113  * A buffer that contains a block of DMA-able coherent memory used for
114  * storing a portion of a DMA descriptor program.
115  */
116 struct descriptor_buffer {
117 	struct list_head list;
118 	dma_addr_t buffer_bus;
119 	size_t buffer_size;
120 	size_t used;
121 	struct descriptor buffer[0];
122 };
123 
124 struct context {
125 	struct fw_ohci *ohci;
126 	u32 regs;
127 	int total_allocation;
128 	bool running;
129 	bool flushing;
130 
131 	/*
132 	 * List of page-sized buffers for storing DMA descriptors.
133 	 * Head of list contains buffers in use and tail of list contains
134 	 * free buffers.
135 	 */
136 	struct list_head buffer_list;
137 
138 	/*
139 	 * Pointer to a buffer inside buffer_list that contains the tail
140 	 * end of the current DMA program.
141 	 */
142 	struct descriptor_buffer *buffer_tail;
143 
144 	/*
145 	 * The descriptor containing the branch address of the first
146 	 * descriptor that has not yet been filled by the device.
147 	 */
148 	struct descriptor *last;
149 
150 	/*
151 	 * The last descriptor in the DMA program.  It contains the branch
152 	 * address that must be updated upon appending a new descriptor.
153 	 */
154 	struct descriptor *prev;
155 
156 	descriptor_callback_t callback;
157 
158 	struct tasklet_struct tasklet;
159 };
160 
161 #define IT_HEADER_SY(v)          ((v) <<  0)
162 #define IT_HEADER_TCODE(v)       ((v) <<  4)
163 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
164 #define IT_HEADER_TAG(v)         ((v) << 14)
165 #define IT_HEADER_SPEED(v)       ((v) << 16)
166 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
167 
168 struct iso_context {
169 	struct fw_iso_context base;
170 	struct context context;
171 	int excess_bytes;
172 	void *header;
173 	size_t header_length;
174 
175 	u8 sync;
176 	u8 tags;
177 };
178 
179 #define CONFIG_ROM_SIZE 1024
180 
181 struct fw_ohci {
182 	struct fw_card card;
183 
184 	__iomem char *registers;
185 	int node_id;
186 	int generation;
187 	int request_generation;	/* for timestamping incoming requests */
188 	unsigned quirks;
189 	unsigned int pri_req_max;
190 	u32 bus_time;
191 	bool is_root;
192 	bool csr_state_setclear_abdicate;
193 	int n_ir;
194 	int n_it;
195 	/*
196 	 * Spinlock for accessing fw_ohci data.  Never call out of
197 	 * this driver with this lock held.
198 	 */
199 	spinlock_t lock;
200 
201 	struct mutex phy_reg_mutex;
202 
203 	void *misc_buffer;
204 	dma_addr_t misc_buffer_bus;
205 
206 	struct ar_context ar_request_ctx;
207 	struct ar_context ar_response_ctx;
208 	struct context at_request_ctx;
209 	struct context at_response_ctx;
210 
211 	u32 it_context_support;
212 	u32 it_context_mask;     /* unoccupied IT contexts */
213 	struct iso_context *it_context_list;
214 	u64 ir_context_channels; /* unoccupied channels */
215 	u32 ir_context_support;
216 	u32 ir_context_mask;     /* unoccupied IR contexts */
217 	struct iso_context *ir_context_list;
218 	u64 mc_channels; /* channels in use by the multichannel IR context */
219 	bool mc_allocated;
220 
221 	__be32    *config_rom;
222 	dma_addr_t config_rom_bus;
223 	__be32    *next_config_rom;
224 	dma_addr_t next_config_rom_bus;
225 	__be32     next_header;
226 
227 	__le32    *self_id_cpu;
228 	dma_addr_t self_id_bus;
229 	struct tasklet_struct bus_reset_tasklet;
230 
231 	u32 self_id_buffer[512];
232 };
233 
234 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
235 {
236 	return container_of(card, struct fw_ohci, card);
237 }
238 
239 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
240 #define IR_CONTEXT_BUFFER_FILL		0x80000000
241 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
242 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
243 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
244 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
245 
246 #define CONTEXT_RUN	0x8000
247 #define CONTEXT_WAKE	0x1000
248 #define CONTEXT_DEAD	0x0800
249 #define CONTEXT_ACTIVE	0x0400
250 
251 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
252 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
253 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
254 
255 #define OHCI1394_REGISTER_SIZE		0x800
256 #define OHCI_LOOP_COUNT			500
257 #define OHCI1394_PCI_HCI_Control	0x40
258 #define SELF_ID_BUF_SIZE		0x800
259 #define OHCI_TCODE_PHY_PACKET		0x0e
260 #define OHCI_VERSION_1_1		0x010010
261 
262 static char ohci_driver_name[] = KBUILD_MODNAME;
263 
264 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
265 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
266 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
267 
268 #define QUIRK_CYCLE_TIMER		1
269 #define QUIRK_RESET_PACKET		2
270 #define QUIRK_BE_HEADERS		4
271 #define QUIRK_NO_1394A			8
272 #define QUIRK_NO_MSI			16
273 
274 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
275 static const struct {
276 	unsigned short vendor, device, revision, flags;
277 } ohci_quirks[] = {
278 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
279 		QUIRK_CYCLE_TIMER},
280 
281 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
282 		QUIRK_BE_HEADERS},
283 
284 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
285 		QUIRK_NO_MSI},
286 
287 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
288 		QUIRK_NO_MSI},
289 
290 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
291 		QUIRK_CYCLE_TIMER},
292 
293 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
294 		QUIRK_CYCLE_TIMER},
295 
296 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
297 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
298 
299 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
300 		QUIRK_RESET_PACKET},
301 
302 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
303 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
304 };
305 
306 /* This overrides anything that was found in ohci_quirks[]. */
307 static int param_quirks;
308 module_param_named(quirks, param_quirks, int, 0644);
309 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
310 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
311 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
312 	", AR/selfID endianess = "	__stringify(QUIRK_BE_HEADERS)
313 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
314 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
315 	")");
316 
317 #define OHCI_PARAM_DEBUG_AT_AR		1
318 #define OHCI_PARAM_DEBUG_SELFIDS	2
319 #define OHCI_PARAM_DEBUG_IRQS		4
320 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
321 
322 #ifdef CONFIG_FIREWIRE_OHCI_DEBUG
323 
324 static int param_debug;
325 module_param_named(debug, param_debug, int, 0644);
326 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
327 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
328 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
329 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
330 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
331 	", or a combination, or all = -1)");
332 
333 static void log_irqs(u32 evt)
334 {
335 	if (likely(!(param_debug &
336 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
337 		return;
338 
339 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
340 	    !(evt & OHCI1394_busReset))
341 		return;
342 
343 	fw_notify("IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
344 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
345 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
346 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
347 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
348 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
349 	    evt & OHCI1394_isochRx		? " IR"			: "",
350 	    evt & OHCI1394_isochTx		? " IT"			: "",
351 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
352 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
353 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
354 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
355 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
356 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
357 	    evt & OHCI1394_busReset		? " busReset"		: "",
358 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
359 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
360 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
361 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
362 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
363 		    OHCI1394_cycleInconsistent |
364 		    OHCI1394_regAccessFail | OHCI1394_busReset)
365 						? " ?"			: "");
366 }
367 
368 static const char *speed[] = {
369 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
370 };
371 static const char *power[] = {
372 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
373 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
374 };
375 static const char port[] = { '.', '-', 'p', 'c', };
376 
377 static char _p(u32 *s, int shift)
378 {
379 	return port[*s >> shift & 3];
380 }
381 
382 static void log_selfids(int node_id, int generation, int self_id_count, u32 *s)
383 {
384 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
385 		return;
386 
387 	fw_notify("%d selfIDs, generation %d, local node ID %04x\n",
388 		  self_id_count, generation, node_id);
389 
390 	for (; self_id_count--; ++s)
391 		if ((*s & 1 << 23) == 0)
392 			fw_notify("selfID 0: %08x, phy %d [%c%c%c] "
393 			    "%s gc=%d %s %s%s%s\n",
394 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
395 			    speed[*s >> 14 & 3], *s >> 16 & 63,
396 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
397 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
398 		else
399 			fw_notify("selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
400 			    *s, *s >> 24 & 63,
401 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
402 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
403 }
404 
405 static const char *evts[] = {
406 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
407 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
408 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
409 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
410 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
411 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
412 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
413 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
414 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
415 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
416 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
417 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
418 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
419 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
420 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
421 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
422 	[0x20] = "pending/cancelled",
423 };
424 static const char *tcodes[] = {
425 	[0x0] = "QW req",		[0x1] = "BW req",
426 	[0x2] = "W resp",		[0x3] = "-reserved-",
427 	[0x4] = "QR req",		[0x5] = "BR req",
428 	[0x6] = "QR resp",		[0x7] = "BR resp",
429 	[0x8] = "cycle start",		[0x9] = "Lk req",
430 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
431 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
432 	[0xe] = "link internal",	[0xf] = "-reserved-",
433 };
434 
435 static void log_ar_at_event(char dir, int speed, u32 *header, int evt)
436 {
437 	int tcode = header[0] >> 4 & 0xf;
438 	char specific[12];
439 
440 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
441 		return;
442 
443 	if (unlikely(evt >= ARRAY_SIZE(evts)))
444 			evt = 0x1f;
445 
446 	if (evt == OHCI1394_evt_bus_reset) {
447 		fw_notify("A%c evt_bus_reset, generation %d\n",
448 		    dir, (header[2] >> 16) & 0xff);
449 		return;
450 	}
451 
452 	switch (tcode) {
453 	case 0x0: case 0x6: case 0x8:
454 		snprintf(specific, sizeof(specific), " = %08x",
455 			 be32_to_cpu((__force __be32)header[3]));
456 		break;
457 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
458 		snprintf(specific, sizeof(specific), " %x,%x",
459 			 header[3] >> 16, header[3] & 0xffff);
460 		break;
461 	default:
462 		specific[0] = '\0';
463 	}
464 
465 	switch (tcode) {
466 	case 0xa:
467 		fw_notify("A%c %s, %s\n", dir, evts[evt], tcodes[tcode]);
468 		break;
469 	case 0xe:
470 		fw_notify("A%c %s, PHY %08x %08x\n",
471 			  dir, evts[evt], header[1], header[2]);
472 		break;
473 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
474 		fw_notify("A%c spd %x tl %02x, "
475 		    "%04x -> %04x, %s, "
476 		    "%s, %04x%08x%s\n",
477 		    dir, speed, header[0] >> 10 & 0x3f,
478 		    header[1] >> 16, header[0] >> 16, evts[evt],
479 		    tcodes[tcode], header[1] & 0xffff, header[2], specific);
480 		break;
481 	default:
482 		fw_notify("A%c spd %x tl %02x, "
483 		    "%04x -> %04x, %s, "
484 		    "%s%s\n",
485 		    dir, speed, header[0] >> 10 & 0x3f,
486 		    header[1] >> 16, header[0] >> 16, evts[evt],
487 		    tcodes[tcode], specific);
488 	}
489 }
490 
491 #else
492 
493 #define param_debug 0
494 static inline void log_irqs(u32 evt) {}
495 static inline void log_selfids(int node_id, int generation, int self_id_count, u32 *s) {}
496 static inline void log_ar_at_event(char dir, int speed, u32 *header, int evt) {}
497 
498 #endif /* CONFIG_FIREWIRE_OHCI_DEBUG */
499 
500 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
501 {
502 	writel(data, ohci->registers + offset);
503 }
504 
505 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
506 {
507 	return readl(ohci->registers + offset);
508 }
509 
510 static inline void flush_writes(const struct fw_ohci *ohci)
511 {
512 	/* Do a dummy read to flush writes. */
513 	reg_read(ohci, OHCI1394_Version);
514 }
515 
516 static int read_phy_reg(struct fw_ohci *ohci, int addr)
517 {
518 	u32 val;
519 	int i;
520 
521 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
522 	for (i = 0; i < 3 + 100; i++) {
523 		val = reg_read(ohci, OHCI1394_PhyControl);
524 		if (val & OHCI1394_PhyControl_ReadDone)
525 			return OHCI1394_PhyControl_ReadData(val);
526 
527 		/*
528 		 * Try a few times without waiting.  Sleeping is necessary
529 		 * only when the link/PHY interface is busy.
530 		 */
531 		if (i >= 3)
532 			msleep(1);
533 	}
534 	fw_error("failed to read phy reg\n");
535 
536 	return -EBUSY;
537 }
538 
539 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
540 {
541 	int i;
542 
543 	reg_write(ohci, OHCI1394_PhyControl,
544 		  OHCI1394_PhyControl_Write(addr, val));
545 	for (i = 0; i < 3 + 100; i++) {
546 		val = reg_read(ohci, OHCI1394_PhyControl);
547 		if (!(val & OHCI1394_PhyControl_WritePending))
548 			return 0;
549 
550 		if (i >= 3)
551 			msleep(1);
552 	}
553 	fw_error("failed to write phy reg\n");
554 
555 	return -EBUSY;
556 }
557 
558 static int update_phy_reg(struct fw_ohci *ohci, int addr,
559 			  int clear_bits, int set_bits)
560 {
561 	int ret = read_phy_reg(ohci, addr);
562 	if (ret < 0)
563 		return ret;
564 
565 	/*
566 	 * The interrupt status bits are cleared by writing a one bit.
567 	 * Avoid clearing them unless explicitly requested in set_bits.
568 	 */
569 	if (addr == 5)
570 		clear_bits |= PHY_INT_STATUS_BITS;
571 
572 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
573 }
574 
575 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
576 {
577 	int ret;
578 
579 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
580 	if (ret < 0)
581 		return ret;
582 
583 	return read_phy_reg(ohci, addr);
584 }
585 
586 static int ohci_read_phy_reg(struct fw_card *card, int addr)
587 {
588 	struct fw_ohci *ohci = fw_ohci(card);
589 	int ret;
590 
591 	mutex_lock(&ohci->phy_reg_mutex);
592 	ret = read_phy_reg(ohci, addr);
593 	mutex_unlock(&ohci->phy_reg_mutex);
594 
595 	return ret;
596 }
597 
598 static int ohci_update_phy_reg(struct fw_card *card, int addr,
599 			       int clear_bits, int set_bits)
600 {
601 	struct fw_ohci *ohci = fw_ohci(card);
602 	int ret;
603 
604 	mutex_lock(&ohci->phy_reg_mutex);
605 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
606 	mutex_unlock(&ohci->phy_reg_mutex);
607 
608 	return ret;
609 }
610 
611 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
612 {
613 	return page_private(ctx->pages[i]);
614 }
615 
616 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
617 {
618 	struct descriptor *d;
619 
620 	d = &ctx->descriptors[index];
621 	d->branch_address  &= cpu_to_le32(~0xf);
622 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
623 	d->transfer_status =  0;
624 
625 	wmb(); /* finish init of new descriptors before branch_address update */
626 	d = &ctx->descriptors[ctx->last_buffer_index];
627 	d->branch_address  |= cpu_to_le32(1);
628 
629 	ctx->last_buffer_index = index;
630 
631 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
632 	flush_writes(ctx->ohci);
633 }
634 
635 static void ar_context_release(struct ar_context *ctx)
636 {
637 	unsigned int i;
638 
639 	if (ctx->buffer)
640 		vm_unmap_ram(ctx->buffer, AR_BUFFERS + AR_WRAPAROUND_PAGES);
641 
642 	for (i = 0; i < AR_BUFFERS; i++)
643 		if (ctx->pages[i]) {
644 			dma_unmap_page(ctx->ohci->card.device,
645 				       ar_buffer_bus(ctx, i),
646 				       PAGE_SIZE, DMA_FROM_DEVICE);
647 			__free_page(ctx->pages[i]);
648 		}
649 }
650 
651 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
652 {
653 	if (reg_read(ctx->ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
654 		reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
655 		flush_writes(ctx->ohci);
656 
657 		fw_error("AR error: %s; DMA stopped\n", error_msg);
658 	}
659 	/* FIXME: restart? */
660 }
661 
662 static inline unsigned int ar_next_buffer_index(unsigned int index)
663 {
664 	return (index + 1) % AR_BUFFERS;
665 }
666 
667 static inline unsigned int ar_prev_buffer_index(unsigned int index)
668 {
669 	return (index - 1 + AR_BUFFERS) % AR_BUFFERS;
670 }
671 
672 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
673 {
674 	return ar_next_buffer_index(ctx->last_buffer_index);
675 }
676 
677 /*
678  * We search for the buffer that contains the last AR packet DMA data written
679  * by the controller.
680  */
681 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
682 						 unsigned int *buffer_offset)
683 {
684 	unsigned int i, next_i, last = ctx->last_buffer_index;
685 	__le16 res_count, next_res_count;
686 
687 	i = ar_first_buffer_index(ctx);
688 	res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
689 
690 	/* A buffer that is not yet completely filled must be the last one. */
691 	while (i != last && res_count == 0) {
692 
693 		/* Peek at the next descriptor. */
694 		next_i = ar_next_buffer_index(i);
695 		rmb(); /* read descriptors in order */
696 		next_res_count = ACCESS_ONCE(
697 				ctx->descriptors[next_i].res_count);
698 		/*
699 		 * If the next descriptor is still empty, we must stop at this
700 		 * descriptor.
701 		 */
702 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
703 			/*
704 			 * The exception is when the DMA data for one packet is
705 			 * split over three buffers; in this case, the middle
706 			 * buffer's descriptor might be never updated by the
707 			 * controller and look still empty, and we have to peek
708 			 * at the third one.
709 			 */
710 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
711 				next_i = ar_next_buffer_index(next_i);
712 				rmb();
713 				next_res_count = ACCESS_ONCE(
714 					ctx->descriptors[next_i].res_count);
715 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
716 					goto next_buffer_is_active;
717 			}
718 
719 			break;
720 		}
721 
722 next_buffer_is_active:
723 		i = next_i;
724 		res_count = next_res_count;
725 	}
726 
727 	rmb(); /* read res_count before the DMA data */
728 
729 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
730 	if (*buffer_offset > PAGE_SIZE) {
731 		*buffer_offset = 0;
732 		ar_context_abort(ctx, "corrupted descriptor");
733 	}
734 
735 	return i;
736 }
737 
738 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
739 				    unsigned int end_buffer_index,
740 				    unsigned int end_buffer_offset)
741 {
742 	unsigned int i;
743 
744 	i = ar_first_buffer_index(ctx);
745 	while (i != end_buffer_index) {
746 		dma_sync_single_for_cpu(ctx->ohci->card.device,
747 					ar_buffer_bus(ctx, i),
748 					PAGE_SIZE, DMA_FROM_DEVICE);
749 		i = ar_next_buffer_index(i);
750 	}
751 	if (end_buffer_offset > 0)
752 		dma_sync_single_for_cpu(ctx->ohci->card.device,
753 					ar_buffer_bus(ctx, i),
754 					end_buffer_offset, DMA_FROM_DEVICE);
755 }
756 
757 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
758 #define cond_le32_to_cpu(v) \
759 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
760 #else
761 #define cond_le32_to_cpu(v) le32_to_cpu(v)
762 #endif
763 
764 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
765 {
766 	struct fw_ohci *ohci = ctx->ohci;
767 	struct fw_packet p;
768 	u32 status, length, tcode;
769 	int evt;
770 
771 	p.header[0] = cond_le32_to_cpu(buffer[0]);
772 	p.header[1] = cond_le32_to_cpu(buffer[1]);
773 	p.header[2] = cond_le32_to_cpu(buffer[2]);
774 
775 	tcode = (p.header[0] >> 4) & 0x0f;
776 	switch (tcode) {
777 	case TCODE_WRITE_QUADLET_REQUEST:
778 	case TCODE_READ_QUADLET_RESPONSE:
779 		p.header[3] = (__force __u32) buffer[3];
780 		p.header_length = 16;
781 		p.payload_length = 0;
782 		break;
783 
784 	case TCODE_READ_BLOCK_REQUEST :
785 		p.header[3] = cond_le32_to_cpu(buffer[3]);
786 		p.header_length = 16;
787 		p.payload_length = 0;
788 		break;
789 
790 	case TCODE_WRITE_BLOCK_REQUEST:
791 	case TCODE_READ_BLOCK_RESPONSE:
792 	case TCODE_LOCK_REQUEST:
793 	case TCODE_LOCK_RESPONSE:
794 		p.header[3] = cond_le32_to_cpu(buffer[3]);
795 		p.header_length = 16;
796 		p.payload_length = p.header[3] >> 16;
797 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
798 			ar_context_abort(ctx, "invalid packet length");
799 			return NULL;
800 		}
801 		break;
802 
803 	case TCODE_WRITE_RESPONSE:
804 	case TCODE_READ_QUADLET_REQUEST:
805 	case OHCI_TCODE_PHY_PACKET:
806 		p.header_length = 12;
807 		p.payload_length = 0;
808 		break;
809 
810 	default:
811 		ar_context_abort(ctx, "invalid tcode");
812 		return NULL;
813 	}
814 
815 	p.payload = (void *) buffer + p.header_length;
816 
817 	/* FIXME: What to do about evt_* errors? */
818 	length = (p.header_length + p.payload_length + 3) / 4;
819 	status = cond_le32_to_cpu(buffer[length]);
820 	evt    = (status >> 16) & 0x1f;
821 
822 	p.ack        = evt - 16;
823 	p.speed      = (status >> 21) & 0x7;
824 	p.timestamp  = status & 0xffff;
825 	p.generation = ohci->request_generation;
826 
827 	log_ar_at_event('R', p.speed, p.header, evt);
828 
829 	/*
830 	 * Several controllers, notably from NEC and VIA, forget to
831 	 * write ack_complete status at PHY packet reception.
832 	 */
833 	if (evt == OHCI1394_evt_no_status &&
834 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
835 		p.ack = ACK_COMPLETE;
836 
837 	/*
838 	 * The OHCI bus reset handler synthesizes a PHY packet with
839 	 * the new generation number when a bus reset happens (see
840 	 * section 8.4.2.3).  This helps us determine when a request
841 	 * was received and make sure we send the response in the same
842 	 * generation.  We only need this for requests; for responses
843 	 * we use the unique tlabel for finding the matching
844 	 * request.
845 	 *
846 	 * Alas some chips sometimes emit bus reset packets with a
847 	 * wrong generation.  We set the correct generation for these
848 	 * at a slightly incorrect time (in bus_reset_tasklet).
849 	 */
850 	if (evt == OHCI1394_evt_bus_reset) {
851 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
852 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
853 	} else if (ctx == &ohci->ar_request_ctx) {
854 		fw_core_handle_request(&ohci->card, &p);
855 	} else {
856 		fw_core_handle_response(&ohci->card, &p);
857 	}
858 
859 	return buffer + length + 1;
860 }
861 
862 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
863 {
864 	void *next;
865 
866 	while (p < end) {
867 		next = handle_ar_packet(ctx, p);
868 		if (!next)
869 			return p;
870 		p = next;
871 	}
872 
873 	return p;
874 }
875 
876 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
877 {
878 	unsigned int i;
879 
880 	i = ar_first_buffer_index(ctx);
881 	while (i != end_buffer) {
882 		dma_sync_single_for_device(ctx->ohci->card.device,
883 					   ar_buffer_bus(ctx, i),
884 					   PAGE_SIZE, DMA_FROM_DEVICE);
885 		ar_context_link_page(ctx, i);
886 		i = ar_next_buffer_index(i);
887 	}
888 }
889 
890 static void ar_context_tasklet(unsigned long data)
891 {
892 	struct ar_context *ctx = (struct ar_context *)data;
893 	unsigned int end_buffer_index, end_buffer_offset;
894 	void *p, *end;
895 
896 	p = ctx->pointer;
897 	if (!p)
898 		return;
899 
900 	end_buffer_index = ar_search_last_active_buffer(ctx,
901 							&end_buffer_offset);
902 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
903 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
904 
905 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
906 		/*
907 		 * The filled part of the overall buffer wraps around; handle
908 		 * all packets up to the buffer end here.  If the last packet
909 		 * wraps around, its tail will be visible after the buffer end
910 		 * because the buffer start pages are mapped there again.
911 		 */
912 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
913 		p = handle_ar_packets(ctx, p, buffer_end);
914 		if (p < buffer_end)
915 			goto error;
916 		/* adjust p to point back into the actual buffer */
917 		p -= AR_BUFFERS * PAGE_SIZE;
918 	}
919 
920 	p = handle_ar_packets(ctx, p, end);
921 	if (p != end) {
922 		if (p > end)
923 			ar_context_abort(ctx, "inconsistent descriptor");
924 		goto error;
925 	}
926 
927 	ctx->pointer = p;
928 	ar_recycle_buffers(ctx, end_buffer_index);
929 
930 	return;
931 
932 error:
933 	ctx->pointer = NULL;
934 }
935 
936 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
937 			   unsigned int descriptors_offset, u32 regs)
938 {
939 	unsigned int i;
940 	dma_addr_t dma_addr;
941 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
942 	struct descriptor *d;
943 
944 	ctx->regs        = regs;
945 	ctx->ohci        = ohci;
946 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
947 
948 	for (i = 0; i < AR_BUFFERS; i++) {
949 		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
950 		if (!ctx->pages[i])
951 			goto out_of_memory;
952 		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
953 					0, PAGE_SIZE, DMA_FROM_DEVICE);
954 		if (dma_mapping_error(ohci->card.device, dma_addr)) {
955 			__free_page(ctx->pages[i]);
956 			ctx->pages[i] = NULL;
957 			goto out_of_memory;
958 		}
959 		set_page_private(ctx->pages[i], dma_addr);
960 	}
961 
962 	for (i = 0; i < AR_BUFFERS; i++)
963 		pages[i]              = ctx->pages[i];
964 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
965 		pages[AR_BUFFERS + i] = ctx->pages[i];
966 	ctx->buffer = vm_map_ram(pages, AR_BUFFERS + AR_WRAPAROUND_PAGES,
967 				 -1, PAGE_KERNEL);
968 	if (!ctx->buffer)
969 		goto out_of_memory;
970 
971 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
972 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
973 
974 	for (i = 0; i < AR_BUFFERS; i++) {
975 		d = &ctx->descriptors[i];
976 		d->req_count      = cpu_to_le16(PAGE_SIZE);
977 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
978 						DESCRIPTOR_STATUS |
979 						DESCRIPTOR_BRANCH_ALWAYS);
980 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
981 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
982 			ar_next_buffer_index(i) * sizeof(struct descriptor));
983 	}
984 
985 	return 0;
986 
987 out_of_memory:
988 	ar_context_release(ctx);
989 
990 	return -ENOMEM;
991 }
992 
993 static void ar_context_run(struct ar_context *ctx)
994 {
995 	unsigned int i;
996 
997 	for (i = 0; i < AR_BUFFERS; i++)
998 		ar_context_link_page(ctx, i);
999 
1000 	ctx->pointer = ctx->buffer;
1001 
1002 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1003 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1004 	flush_writes(ctx->ohci);
1005 }
1006 
1007 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1008 {
1009 	__le16 branch;
1010 
1011 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1012 
1013 	/* figure out which descriptor the branch address goes in */
1014 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1015 		return d;
1016 	else
1017 		return d + z - 1;
1018 }
1019 
1020 static void context_tasklet(unsigned long data)
1021 {
1022 	struct context *ctx = (struct context *) data;
1023 	struct descriptor *d, *last;
1024 	u32 address;
1025 	int z;
1026 	struct descriptor_buffer *desc;
1027 
1028 	desc = list_entry(ctx->buffer_list.next,
1029 			struct descriptor_buffer, list);
1030 	last = ctx->last;
1031 	while (last->branch_address != 0) {
1032 		struct descriptor_buffer *old_desc = desc;
1033 		address = le32_to_cpu(last->branch_address);
1034 		z = address & 0xf;
1035 		address &= ~0xf;
1036 
1037 		/* If the branch address points to a buffer outside of the
1038 		 * current buffer, advance to the next buffer. */
1039 		if (address < desc->buffer_bus ||
1040 				address >= desc->buffer_bus + desc->used)
1041 			desc = list_entry(desc->list.next,
1042 					struct descriptor_buffer, list);
1043 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1044 		last = find_branch_descriptor(d, z);
1045 
1046 		if (!ctx->callback(ctx, d, last))
1047 			break;
1048 
1049 		if (old_desc != desc) {
1050 			/* If we've advanced to the next buffer, move the
1051 			 * previous buffer to the free list. */
1052 			unsigned long flags;
1053 			old_desc->used = 0;
1054 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1055 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1056 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1057 		}
1058 		ctx->last = last;
1059 	}
1060 }
1061 
1062 /*
1063  * Allocate a new buffer and add it to the list of free buffers for this
1064  * context.  Must be called with ohci->lock held.
1065  */
1066 static int context_add_buffer(struct context *ctx)
1067 {
1068 	struct descriptor_buffer *desc;
1069 	dma_addr_t uninitialized_var(bus_addr);
1070 	int offset;
1071 
1072 	/*
1073 	 * 16MB of descriptors should be far more than enough for any DMA
1074 	 * program.  This will catch run-away userspace or DoS attacks.
1075 	 */
1076 	if (ctx->total_allocation >= 16*1024*1024)
1077 		return -ENOMEM;
1078 
1079 	desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1080 			&bus_addr, GFP_ATOMIC);
1081 	if (!desc)
1082 		return -ENOMEM;
1083 
1084 	offset = (void *)&desc->buffer - (void *)desc;
1085 	desc->buffer_size = PAGE_SIZE - offset;
1086 	desc->buffer_bus = bus_addr + offset;
1087 	desc->used = 0;
1088 
1089 	list_add_tail(&desc->list, &ctx->buffer_list);
1090 	ctx->total_allocation += PAGE_SIZE;
1091 
1092 	return 0;
1093 }
1094 
1095 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1096 			u32 regs, descriptor_callback_t callback)
1097 {
1098 	ctx->ohci = ohci;
1099 	ctx->regs = regs;
1100 	ctx->total_allocation = 0;
1101 
1102 	INIT_LIST_HEAD(&ctx->buffer_list);
1103 	if (context_add_buffer(ctx) < 0)
1104 		return -ENOMEM;
1105 
1106 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1107 			struct descriptor_buffer, list);
1108 
1109 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1110 	ctx->callback = callback;
1111 
1112 	/*
1113 	 * We put a dummy descriptor in the buffer that has a NULL
1114 	 * branch address and looks like it's been sent.  That way we
1115 	 * have a descriptor to append DMA programs to.
1116 	 */
1117 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1118 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1119 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1120 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1121 	ctx->last = ctx->buffer_tail->buffer;
1122 	ctx->prev = ctx->buffer_tail->buffer;
1123 
1124 	return 0;
1125 }
1126 
1127 static void context_release(struct context *ctx)
1128 {
1129 	struct fw_card *card = &ctx->ohci->card;
1130 	struct descriptor_buffer *desc, *tmp;
1131 
1132 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1133 		dma_free_coherent(card->device, PAGE_SIZE, desc,
1134 			desc->buffer_bus -
1135 			((void *)&desc->buffer - (void *)desc));
1136 }
1137 
1138 /* Must be called with ohci->lock held */
1139 static struct descriptor *context_get_descriptors(struct context *ctx,
1140 						  int z, dma_addr_t *d_bus)
1141 {
1142 	struct descriptor *d = NULL;
1143 	struct descriptor_buffer *desc = ctx->buffer_tail;
1144 
1145 	if (z * sizeof(*d) > desc->buffer_size)
1146 		return NULL;
1147 
1148 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1149 		/* No room for the descriptor in this buffer, so advance to the
1150 		 * next one. */
1151 
1152 		if (desc->list.next == &ctx->buffer_list) {
1153 			/* If there is no free buffer next in the list,
1154 			 * allocate one. */
1155 			if (context_add_buffer(ctx) < 0)
1156 				return NULL;
1157 		}
1158 		desc = list_entry(desc->list.next,
1159 				struct descriptor_buffer, list);
1160 		ctx->buffer_tail = desc;
1161 	}
1162 
1163 	d = desc->buffer + desc->used / sizeof(*d);
1164 	memset(d, 0, z * sizeof(*d));
1165 	*d_bus = desc->buffer_bus + desc->used;
1166 
1167 	return d;
1168 }
1169 
1170 static void context_run(struct context *ctx, u32 extra)
1171 {
1172 	struct fw_ohci *ohci = ctx->ohci;
1173 
1174 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1175 		  le32_to_cpu(ctx->last->branch_address));
1176 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1177 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1178 	ctx->running = true;
1179 	flush_writes(ohci);
1180 }
1181 
1182 static void context_append(struct context *ctx,
1183 			   struct descriptor *d, int z, int extra)
1184 {
1185 	dma_addr_t d_bus;
1186 	struct descriptor_buffer *desc = ctx->buffer_tail;
1187 
1188 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1189 
1190 	desc->used += (z + extra) * sizeof(*d);
1191 
1192 	wmb(); /* finish init of new descriptors before branch_address update */
1193 	ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1194 	ctx->prev = find_branch_descriptor(d, z);
1195 }
1196 
1197 static void context_stop(struct context *ctx)
1198 {
1199 	u32 reg;
1200 	int i;
1201 
1202 	reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1203 	ctx->running = false;
1204 	flush_writes(ctx->ohci);
1205 
1206 	for (i = 0; i < 10; i++) {
1207 		reg = reg_read(ctx->ohci, CONTROL_SET(ctx->regs));
1208 		if ((reg & CONTEXT_ACTIVE) == 0)
1209 			return;
1210 
1211 		mdelay(1);
1212 	}
1213 	fw_error("Error: DMA context still active (0x%08x)\n", reg);
1214 }
1215 
1216 struct driver_data {
1217 	u8 inline_data[8];
1218 	struct fw_packet *packet;
1219 };
1220 
1221 /*
1222  * This function apppends a packet to the DMA queue for transmission.
1223  * Must always be called with the ochi->lock held to ensure proper
1224  * generation handling and locking around packet queue manipulation.
1225  */
1226 static int at_context_queue_packet(struct context *ctx,
1227 				   struct fw_packet *packet)
1228 {
1229 	struct fw_ohci *ohci = ctx->ohci;
1230 	dma_addr_t d_bus, uninitialized_var(payload_bus);
1231 	struct driver_data *driver_data;
1232 	struct descriptor *d, *last;
1233 	__le32 *header;
1234 	int z, tcode;
1235 
1236 	d = context_get_descriptors(ctx, 4, &d_bus);
1237 	if (d == NULL) {
1238 		packet->ack = RCODE_SEND_ERROR;
1239 		return -1;
1240 	}
1241 
1242 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1243 	d[0].res_count = cpu_to_le16(packet->timestamp);
1244 
1245 	/*
1246 	 * The DMA format for asyncronous link packets is different
1247 	 * from the IEEE1394 layout, so shift the fields around
1248 	 * accordingly.
1249 	 */
1250 
1251 	tcode = (packet->header[0] >> 4) & 0x0f;
1252 	header = (__le32 *) &d[1];
1253 	switch (tcode) {
1254 	case TCODE_WRITE_QUADLET_REQUEST:
1255 	case TCODE_WRITE_BLOCK_REQUEST:
1256 	case TCODE_WRITE_RESPONSE:
1257 	case TCODE_READ_QUADLET_REQUEST:
1258 	case TCODE_READ_BLOCK_REQUEST:
1259 	case TCODE_READ_QUADLET_RESPONSE:
1260 	case TCODE_READ_BLOCK_RESPONSE:
1261 	case TCODE_LOCK_REQUEST:
1262 	case TCODE_LOCK_RESPONSE:
1263 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1264 					(packet->speed << 16));
1265 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1266 					(packet->header[0] & 0xffff0000));
1267 		header[2] = cpu_to_le32(packet->header[2]);
1268 
1269 		if (TCODE_IS_BLOCK_PACKET(tcode))
1270 			header[3] = cpu_to_le32(packet->header[3]);
1271 		else
1272 			header[3] = (__force __le32) packet->header[3];
1273 
1274 		d[0].req_count = cpu_to_le16(packet->header_length);
1275 		break;
1276 
1277 	case TCODE_LINK_INTERNAL:
1278 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1279 					(packet->speed << 16));
1280 		header[1] = cpu_to_le32(packet->header[1]);
1281 		header[2] = cpu_to_le32(packet->header[2]);
1282 		d[0].req_count = cpu_to_le16(12);
1283 
1284 		if (is_ping_packet(&packet->header[1]))
1285 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1286 		break;
1287 
1288 	case TCODE_STREAM_DATA:
1289 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1290 					(packet->speed << 16));
1291 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1292 		d[0].req_count = cpu_to_le16(8);
1293 		break;
1294 
1295 	default:
1296 		/* BUG(); */
1297 		packet->ack = RCODE_SEND_ERROR;
1298 		return -1;
1299 	}
1300 
1301 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1302 	driver_data = (struct driver_data *) &d[3];
1303 	driver_data->packet = packet;
1304 	packet->driver_data = driver_data;
1305 
1306 	if (packet->payload_length > 0) {
1307 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1308 			payload_bus = dma_map_single(ohci->card.device,
1309 						     packet->payload,
1310 						     packet->payload_length,
1311 						     DMA_TO_DEVICE);
1312 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1313 				packet->ack = RCODE_SEND_ERROR;
1314 				return -1;
1315 			}
1316 			packet->payload_bus	= payload_bus;
1317 			packet->payload_mapped	= true;
1318 		} else {
1319 			memcpy(driver_data->inline_data, packet->payload,
1320 			       packet->payload_length);
1321 			payload_bus = d_bus + 3 * sizeof(*d);
1322 		}
1323 
1324 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1325 		d[2].data_address = cpu_to_le32(payload_bus);
1326 		last = &d[2];
1327 		z = 3;
1328 	} else {
1329 		last = &d[0];
1330 		z = 2;
1331 	}
1332 
1333 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1334 				     DESCRIPTOR_IRQ_ALWAYS |
1335 				     DESCRIPTOR_BRANCH_ALWAYS);
1336 
1337 	/* FIXME: Document how the locking works. */
1338 	if (ohci->generation != packet->generation) {
1339 		if (packet->payload_mapped)
1340 			dma_unmap_single(ohci->card.device, payload_bus,
1341 					 packet->payload_length, DMA_TO_DEVICE);
1342 		packet->ack = RCODE_GENERATION;
1343 		return -1;
1344 	}
1345 
1346 	context_append(ctx, d, z, 4 - z);
1347 
1348 	if (ctx->running) {
1349 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1350 		flush_writes(ohci);
1351 	} else {
1352 		context_run(ctx, 0);
1353 	}
1354 
1355 	return 0;
1356 }
1357 
1358 static void at_context_flush(struct context *ctx)
1359 {
1360 	tasklet_disable(&ctx->tasklet);
1361 
1362 	ctx->flushing = true;
1363 	context_tasklet((unsigned long)ctx);
1364 	ctx->flushing = false;
1365 
1366 	tasklet_enable(&ctx->tasklet);
1367 }
1368 
1369 static int handle_at_packet(struct context *context,
1370 			    struct descriptor *d,
1371 			    struct descriptor *last)
1372 {
1373 	struct driver_data *driver_data;
1374 	struct fw_packet *packet;
1375 	struct fw_ohci *ohci = context->ohci;
1376 	int evt;
1377 
1378 	if (last->transfer_status == 0 && !context->flushing)
1379 		/* This descriptor isn't done yet, stop iteration. */
1380 		return 0;
1381 
1382 	driver_data = (struct driver_data *) &d[3];
1383 	packet = driver_data->packet;
1384 	if (packet == NULL)
1385 		/* This packet was cancelled, just continue. */
1386 		return 1;
1387 
1388 	if (packet->payload_mapped)
1389 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1390 				 packet->payload_length, DMA_TO_DEVICE);
1391 
1392 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1393 	packet->timestamp = le16_to_cpu(last->res_count);
1394 
1395 	log_ar_at_event('T', packet->speed, packet->header, evt);
1396 
1397 	switch (evt) {
1398 	case OHCI1394_evt_timeout:
1399 		/* Async response transmit timed out. */
1400 		packet->ack = RCODE_CANCELLED;
1401 		break;
1402 
1403 	case OHCI1394_evt_flushed:
1404 		/*
1405 		 * The packet was flushed should give same error as
1406 		 * when we try to use a stale generation count.
1407 		 */
1408 		packet->ack = RCODE_GENERATION;
1409 		break;
1410 
1411 	case OHCI1394_evt_missing_ack:
1412 		if (context->flushing)
1413 			packet->ack = RCODE_GENERATION;
1414 		else {
1415 			/*
1416 			 * Using a valid (current) generation count, but the
1417 			 * node is not on the bus or not sending acks.
1418 			 */
1419 			packet->ack = RCODE_NO_ACK;
1420 		}
1421 		break;
1422 
1423 	case ACK_COMPLETE + 0x10:
1424 	case ACK_PENDING + 0x10:
1425 	case ACK_BUSY_X + 0x10:
1426 	case ACK_BUSY_A + 0x10:
1427 	case ACK_BUSY_B + 0x10:
1428 	case ACK_DATA_ERROR + 0x10:
1429 	case ACK_TYPE_ERROR + 0x10:
1430 		packet->ack = evt - 0x10;
1431 		break;
1432 
1433 	case OHCI1394_evt_no_status:
1434 		if (context->flushing) {
1435 			packet->ack = RCODE_GENERATION;
1436 			break;
1437 		}
1438 		/* fall through */
1439 
1440 	default:
1441 		packet->ack = RCODE_SEND_ERROR;
1442 		break;
1443 	}
1444 
1445 	packet->callback(packet, &ohci->card, packet->ack);
1446 
1447 	return 1;
1448 }
1449 
1450 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1451 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1452 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1453 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1454 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
1455 
1456 static void handle_local_rom(struct fw_ohci *ohci,
1457 			     struct fw_packet *packet, u32 csr)
1458 {
1459 	struct fw_packet response;
1460 	int tcode, length, i;
1461 
1462 	tcode = HEADER_GET_TCODE(packet->header[0]);
1463 	if (TCODE_IS_BLOCK_PACKET(tcode))
1464 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1465 	else
1466 		length = 4;
1467 
1468 	i = csr - CSR_CONFIG_ROM;
1469 	if (i + length > CONFIG_ROM_SIZE) {
1470 		fw_fill_response(&response, packet->header,
1471 				 RCODE_ADDRESS_ERROR, NULL, 0);
1472 	} else if (!TCODE_IS_READ_REQUEST(tcode)) {
1473 		fw_fill_response(&response, packet->header,
1474 				 RCODE_TYPE_ERROR, NULL, 0);
1475 	} else {
1476 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1477 				 (void *) ohci->config_rom + i, length);
1478 	}
1479 
1480 	fw_core_handle_response(&ohci->card, &response);
1481 }
1482 
1483 static void handle_local_lock(struct fw_ohci *ohci,
1484 			      struct fw_packet *packet, u32 csr)
1485 {
1486 	struct fw_packet response;
1487 	int tcode, length, ext_tcode, sel, try;
1488 	__be32 *payload, lock_old;
1489 	u32 lock_arg, lock_data;
1490 
1491 	tcode = HEADER_GET_TCODE(packet->header[0]);
1492 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1493 	payload = packet->payload;
1494 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1495 
1496 	if (tcode == TCODE_LOCK_REQUEST &&
1497 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1498 		lock_arg = be32_to_cpu(payload[0]);
1499 		lock_data = be32_to_cpu(payload[1]);
1500 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1501 		lock_arg = 0;
1502 		lock_data = 0;
1503 	} else {
1504 		fw_fill_response(&response, packet->header,
1505 				 RCODE_TYPE_ERROR, NULL, 0);
1506 		goto out;
1507 	}
1508 
1509 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1510 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1511 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1512 	reg_write(ohci, OHCI1394_CSRControl, sel);
1513 
1514 	for (try = 0; try < 20; try++)
1515 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1516 			lock_old = cpu_to_be32(reg_read(ohci,
1517 							OHCI1394_CSRData));
1518 			fw_fill_response(&response, packet->header,
1519 					 RCODE_COMPLETE,
1520 					 &lock_old, sizeof(lock_old));
1521 			goto out;
1522 		}
1523 
1524 	fw_error("swap not done (CSR lock timeout)\n");
1525 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1526 
1527  out:
1528 	fw_core_handle_response(&ohci->card, &response);
1529 }
1530 
1531 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1532 {
1533 	u64 offset, csr;
1534 
1535 	if (ctx == &ctx->ohci->at_request_ctx) {
1536 		packet->ack = ACK_PENDING;
1537 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1538 	}
1539 
1540 	offset =
1541 		((unsigned long long)
1542 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1543 		packet->header[2];
1544 	csr = offset - CSR_REGISTER_BASE;
1545 
1546 	/* Handle config rom reads. */
1547 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1548 		handle_local_rom(ctx->ohci, packet, csr);
1549 	else switch (csr) {
1550 	case CSR_BUS_MANAGER_ID:
1551 	case CSR_BANDWIDTH_AVAILABLE:
1552 	case CSR_CHANNELS_AVAILABLE_HI:
1553 	case CSR_CHANNELS_AVAILABLE_LO:
1554 		handle_local_lock(ctx->ohci, packet, csr);
1555 		break;
1556 	default:
1557 		if (ctx == &ctx->ohci->at_request_ctx)
1558 			fw_core_handle_request(&ctx->ohci->card, packet);
1559 		else
1560 			fw_core_handle_response(&ctx->ohci->card, packet);
1561 		break;
1562 	}
1563 
1564 	if (ctx == &ctx->ohci->at_response_ctx) {
1565 		packet->ack = ACK_COMPLETE;
1566 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1567 	}
1568 }
1569 
1570 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1571 {
1572 	unsigned long flags;
1573 	int ret;
1574 
1575 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1576 
1577 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1578 	    ctx->ohci->generation == packet->generation) {
1579 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1580 		handle_local_request(ctx, packet);
1581 		return;
1582 	}
1583 
1584 	ret = at_context_queue_packet(ctx, packet);
1585 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1586 
1587 	if (ret < 0)
1588 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1589 
1590 }
1591 
1592 static void detect_dead_context(struct fw_ohci *ohci,
1593 				const char *name, unsigned int regs)
1594 {
1595 	u32 ctl;
1596 
1597 	ctl = reg_read(ohci, CONTROL_SET(regs));
1598 	if (ctl & CONTEXT_DEAD) {
1599 #ifdef CONFIG_FIREWIRE_OHCI_DEBUG
1600 		fw_error("DMA context %s has stopped, error code: %s\n",
1601 			 name, evts[ctl & 0x1f]);
1602 #else
1603 		fw_error("DMA context %s has stopped, error code: %#x\n",
1604 			 name, ctl & 0x1f);
1605 #endif
1606 	}
1607 }
1608 
1609 static void handle_dead_contexts(struct fw_ohci *ohci)
1610 {
1611 	unsigned int i;
1612 	char name[8];
1613 
1614 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1615 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1616 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1617 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1618 	for (i = 0; i < 32; ++i) {
1619 		if (!(ohci->it_context_support & (1 << i)))
1620 			continue;
1621 		sprintf(name, "IT%u", i);
1622 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1623 	}
1624 	for (i = 0; i < 32; ++i) {
1625 		if (!(ohci->ir_context_support & (1 << i)))
1626 			continue;
1627 		sprintf(name, "IR%u", i);
1628 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1629 	}
1630 	/* TODO: maybe try to flush and restart the dead contexts */
1631 }
1632 
1633 static u32 cycle_timer_ticks(u32 cycle_timer)
1634 {
1635 	u32 ticks;
1636 
1637 	ticks = cycle_timer & 0xfff;
1638 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1639 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1640 
1641 	return ticks;
1642 }
1643 
1644 /*
1645  * Some controllers exhibit one or more of the following bugs when updating the
1646  * iso cycle timer register:
1647  *  - When the lowest six bits are wrapping around to zero, a read that happens
1648  *    at the same time will return garbage in the lowest ten bits.
1649  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1650  *    not incremented for about 60 ns.
1651  *  - Occasionally, the entire register reads zero.
1652  *
1653  * To catch these, we read the register three times and ensure that the
1654  * difference between each two consecutive reads is approximately the same, i.e.
1655  * less than twice the other.  Furthermore, any negative difference indicates an
1656  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1657  * execute, so we have enough precision to compute the ratio of the differences.)
1658  */
1659 static u32 get_cycle_time(struct fw_ohci *ohci)
1660 {
1661 	u32 c0, c1, c2;
1662 	u32 t0, t1, t2;
1663 	s32 diff01, diff12;
1664 	int i;
1665 
1666 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1667 
1668 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1669 		i = 0;
1670 		c1 = c2;
1671 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1672 		do {
1673 			c0 = c1;
1674 			c1 = c2;
1675 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1676 			t0 = cycle_timer_ticks(c0);
1677 			t1 = cycle_timer_ticks(c1);
1678 			t2 = cycle_timer_ticks(c2);
1679 			diff01 = t1 - t0;
1680 			diff12 = t2 - t1;
1681 		} while ((diff01 <= 0 || diff12 <= 0 ||
1682 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1683 			 && i++ < 20);
1684 	}
1685 
1686 	return c2;
1687 }
1688 
1689 /*
1690  * This function has to be called at least every 64 seconds.  The bus_time
1691  * field stores not only the upper 25 bits of the BUS_TIME register but also
1692  * the most significant bit of the cycle timer in bit 6 so that we can detect
1693  * changes in this bit.
1694  */
1695 static u32 update_bus_time(struct fw_ohci *ohci)
1696 {
1697 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1698 
1699 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1700 		ohci->bus_time += 0x40;
1701 
1702 	return ohci->bus_time | cycle_time_seconds;
1703 }
1704 
1705 static void bus_reset_tasklet(unsigned long data)
1706 {
1707 	struct fw_ohci *ohci = (struct fw_ohci *)data;
1708 	int self_id_count, i, j, reg;
1709 	int generation, new_generation;
1710 	unsigned long flags;
1711 	void *free_rom = NULL;
1712 	dma_addr_t free_rom_bus = 0;
1713 	bool is_new_root;
1714 
1715 	reg = reg_read(ohci, OHCI1394_NodeID);
1716 	if (!(reg & OHCI1394_NodeID_idValid)) {
1717 		fw_notify("node ID not valid, new bus reset in progress\n");
1718 		return;
1719 	}
1720 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1721 		fw_notify("malconfigured bus\n");
1722 		return;
1723 	}
1724 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1725 			       OHCI1394_NodeID_nodeNumber);
1726 
1727 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1728 	if (!(ohci->is_root && is_new_root))
1729 		reg_write(ohci, OHCI1394_LinkControlSet,
1730 			  OHCI1394_LinkControl_cycleMaster);
1731 	ohci->is_root = is_new_root;
1732 
1733 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1734 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1735 		fw_notify("inconsistent self IDs\n");
1736 		return;
1737 	}
1738 	/*
1739 	 * The count in the SelfIDCount register is the number of
1740 	 * bytes in the self ID receive buffer.  Since we also receive
1741 	 * the inverted quadlets and a header quadlet, we shift one
1742 	 * bit extra to get the actual number of self IDs.
1743 	 */
1744 	self_id_count = (reg >> 3) & 0xff;
1745 	if (self_id_count == 0 || self_id_count > 252) {
1746 		fw_notify("inconsistent self IDs\n");
1747 		return;
1748 	}
1749 	generation = (cond_le32_to_cpu(ohci->self_id_cpu[0]) >> 16) & 0xff;
1750 	rmb();
1751 
1752 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1753 		if (ohci->self_id_cpu[i] != ~ohci->self_id_cpu[i + 1]) {
1754 			fw_notify("inconsistent self IDs\n");
1755 			return;
1756 		}
1757 		ohci->self_id_buffer[j] =
1758 				cond_le32_to_cpu(ohci->self_id_cpu[i]);
1759 	}
1760 	rmb();
1761 
1762 	/*
1763 	 * Check the consistency of the self IDs we just read.  The
1764 	 * problem we face is that a new bus reset can start while we
1765 	 * read out the self IDs from the DMA buffer. If this happens,
1766 	 * the DMA buffer will be overwritten with new self IDs and we
1767 	 * will read out inconsistent data.  The OHCI specification
1768 	 * (section 11.2) recommends a technique similar to
1769 	 * linux/seqlock.h, where we remember the generation of the
1770 	 * self IDs in the buffer before reading them out and compare
1771 	 * it to the current generation after reading them out.  If
1772 	 * the two generations match we know we have a consistent set
1773 	 * of self IDs.
1774 	 */
1775 
1776 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1777 	if (new_generation != generation) {
1778 		fw_notify("recursive bus reset detected, "
1779 			  "discarding self ids\n");
1780 		return;
1781 	}
1782 
1783 	/* FIXME: Document how the locking works. */
1784 	spin_lock_irqsave(&ohci->lock, flags);
1785 
1786 	ohci->generation = -1; /* prevent AT packet queueing */
1787 	context_stop(&ohci->at_request_ctx);
1788 	context_stop(&ohci->at_response_ctx);
1789 
1790 	spin_unlock_irqrestore(&ohci->lock, flags);
1791 
1792 	/*
1793 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
1794 	 * packets in the AT queues and software needs to drain them.
1795 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
1796 	 */
1797 	at_context_flush(&ohci->at_request_ctx);
1798 	at_context_flush(&ohci->at_response_ctx);
1799 
1800 	spin_lock_irqsave(&ohci->lock, flags);
1801 
1802 	ohci->generation = generation;
1803 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
1804 
1805 	if (ohci->quirks & QUIRK_RESET_PACKET)
1806 		ohci->request_generation = generation;
1807 
1808 	/*
1809 	 * This next bit is unrelated to the AT context stuff but we
1810 	 * have to do it under the spinlock also.  If a new config rom
1811 	 * was set up before this reset, the old one is now no longer
1812 	 * in use and we can free it. Update the config rom pointers
1813 	 * to point to the current config rom and clear the
1814 	 * next_config_rom pointer so a new update can take place.
1815 	 */
1816 
1817 	if (ohci->next_config_rom != NULL) {
1818 		if (ohci->next_config_rom != ohci->config_rom) {
1819 			free_rom      = ohci->config_rom;
1820 			free_rom_bus  = ohci->config_rom_bus;
1821 		}
1822 		ohci->config_rom      = ohci->next_config_rom;
1823 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
1824 		ohci->next_config_rom = NULL;
1825 
1826 		/*
1827 		 * Restore config_rom image and manually update
1828 		 * config_rom registers.  Writing the header quadlet
1829 		 * will indicate that the config rom is ready, so we
1830 		 * do that last.
1831 		 */
1832 		reg_write(ohci, OHCI1394_BusOptions,
1833 			  be32_to_cpu(ohci->config_rom[2]));
1834 		ohci->config_rom[0] = ohci->next_header;
1835 		reg_write(ohci, OHCI1394_ConfigROMhdr,
1836 			  be32_to_cpu(ohci->next_header));
1837 	}
1838 
1839 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
1840 	reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
1841 	reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
1842 #endif
1843 
1844 	spin_unlock_irqrestore(&ohci->lock, flags);
1845 
1846 	if (free_rom)
1847 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
1848 				  free_rom, free_rom_bus);
1849 
1850 	log_selfids(ohci->node_id, generation,
1851 		    self_id_count, ohci->self_id_buffer);
1852 
1853 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
1854 				 self_id_count, ohci->self_id_buffer,
1855 				 ohci->csr_state_setclear_abdicate);
1856 	ohci->csr_state_setclear_abdicate = false;
1857 }
1858 
1859 static irqreturn_t irq_handler(int irq, void *data)
1860 {
1861 	struct fw_ohci *ohci = data;
1862 	u32 event, iso_event;
1863 	int i;
1864 
1865 	event = reg_read(ohci, OHCI1394_IntEventClear);
1866 
1867 	if (!event || !~event)
1868 		return IRQ_NONE;
1869 
1870 	/*
1871 	 * busReset and postedWriteErr must not be cleared yet
1872 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
1873 	 */
1874 	reg_write(ohci, OHCI1394_IntEventClear,
1875 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
1876 	log_irqs(event);
1877 
1878 	if (event & OHCI1394_selfIDComplete)
1879 		tasklet_schedule(&ohci->bus_reset_tasklet);
1880 
1881 	if (event & OHCI1394_RQPkt)
1882 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
1883 
1884 	if (event & OHCI1394_RSPkt)
1885 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
1886 
1887 	if (event & OHCI1394_reqTxComplete)
1888 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
1889 
1890 	if (event & OHCI1394_respTxComplete)
1891 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
1892 
1893 	if (event & OHCI1394_isochRx) {
1894 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
1895 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
1896 
1897 		while (iso_event) {
1898 			i = ffs(iso_event) - 1;
1899 			tasklet_schedule(
1900 				&ohci->ir_context_list[i].context.tasklet);
1901 			iso_event &= ~(1 << i);
1902 		}
1903 	}
1904 
1905 	if (event & OHCI1394_isochTx) {
1906 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
1907 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
1908 
1909 		while (iso_event) {
1910 			i = ffs(iso_event) - 1;
1911 			tasklet_schedule(
1912 				&ohci->it_context_list[i].context.tasklet);
1913 			iso_event &= ~(1 << i);
1914 		}
1915 	}
1916 
1917 	if (unlikely(event & OHCI1394_regAccessFail))
1918 		fw_error("Register access failure - "
1919 			 "please notify linux1394-devel@lists.sf.net\n");
1920 
1921 	if (unlikely(event & OHCI1394_postedWriteErr)) {
1922 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
1923 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
1924 		reg_write(ohci, OHCI1394_IntEventClear,
1925 			  OHCI1394_postedWriteErr);
1926 		fw_error("PCI posted write error\n");
1927 	}
1928 
1929 	if (unlikely(event & OHCI1394_cycleTooLong)) {
1930 		if (printk_ratelimit())
1931 			fw_notify("isochronous cycle too long\n");
1932 		reg_write(ohci, OHCI1394_LinkControlSet,
1933 			  OHCI1394_LinkControl_cycleMaster);
1934 	}
1935 
1936 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
1937 		/*
1938 		 * We need to clear this event bit in order to make
1939 		 * cycleMatch isochronous I/O work.  In theory we should
1940 		 * stop active cycleMatch iso contexts now and restart
1941 		 * them at least two cycles later.  (FIXME?)
1942 		 */
1943 		if (printk_ratelimit())
1944 			fw_notify("isochronous cycle inconsistent\n");
1945 	}
1946 
1947 	if (unlikely(event & OHCI1394_unrecoverableError))
1948 		handle_dead_contexts(ohci);
1949 
1950 	if (event & OHCI1394_cycle64Seconds) {
1951 		spin_lock(&ohci->lock);
1952 		update_bus_time(ohci);
1953 		spin_unlock(&ohci->lock);
1954 	} else
1955 		flush_writes(ohci);
1956 
1957 	return IRQ_HANDLED;
1958 }
1959 
1960 static int software_reset(struct fw_ohci *ohci)
1961 {
1962 	int i;
1963 
1964 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
1965 
1966 	for (i = 0; i < OHCI_LOOP_COUNT; i++) {
1967 		if ((reg_read(ohci, OHCI1394_HCControlSet) &
1968 		     OHCI1394_HCControl_softReset) == 0)
1969 			return 0;
1970 		msleep(1);
1971 	}
1972 
1973 	return -EBUSY;
1974 }
1975 
1976 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
1977 {
1978 	size_t size = length * 4;
1979 
1980 	memcpy(dest, src, size);
1981 	if (size < CONFIG_ROM_SIZE)
1982 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
1983 }
1984 
1985 static int configure_1394a_enhancements(struct fw_ohci *ohci)
1986 {
1987 	bool enable_1394a;
1988 	int ret, clear, set, offset;
1989 
1990 	/* Check if the driver should configure link and PHY. */
1991 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
1992 	      OHCI1394_HCControl_programPhyEnable))
1993 		return 0;
1994 
1995 	/* Paranoia: check whether the PHY supports 1394a, too. */
1996 	enable_1394a = false;
1997 	ret = read_phy_reg(ohci, 2);
1998 	if (ret < 0)
1999 		return ret;
2000 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2001 		ret = read_paged_phy_reg(ohci, 1, 8);
2002 		if (ret < 0)
2003 			return ret;
2004 		if (ret >= 1)
2005 			enable_1394a = true;
2006 	}
2007 
2008 	if (ohci->quirks & QUIRK_NO_1394A)
2009 		enable_1394a = false;
2010 
2011 	/* Configure PHY and link consistently. */
2012 	if (enable_1394a) {
2013 		clear = 0;
2014 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2015 	} else {
2016 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2017 		set = 0;
2018 	}
2019 	ret = update_phy_reg(ohci, 5, clear, set);
2020 	if (ret < 0)
2021 		return ret;
2022 
2023 	if (enable_1394a)
2024 		offset = OHCI1394_HCControlSet;
2025 	else
2026 		offset = OHCI1394_HCControlClear;
2027 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2028 
2029 	/* Clean up: configuration has been taken care of. */
2030 	reg_write(ohci, OHCI1394_HCControlClear,
2031 		  OHCI1394_HCControl_programPhyEnable);
2032 
2033 	return 0;
2034 }
2035 
2036 static int ohci_enable(struct fw_card *card,
2037 		       const __be32 *config_rom, size_t length)
2038 {
2039 	struct fw_ohci *ohci = fw_ohci(card);
2040 	struct pci_dev *dev = to_pci_dev(card->device);
2041 	u32 lps, seconds, version, irqs;
2042 	int i, ret;
2043 
2044 	if (software_reset(ohci)) {
2045 		fw_error("Failed to reset ohci card.\n");
2046 		return -EBUSY;
2047 	}
2048 
2049 	/*
2050 	 * Now enable LPS, which we need in order to start accessing
2051 	 * most of the registers.  In fact, on some cards (ALI M5251),
2052 	 * accessing registers in the SClk domain without LPS enabled
2053 	 * will lock up the machine.  Wait 50msec to make sure we have
2054 	 * full link enabled.  However, with some cards (well, at least
2055 	 * a JMicron PCIe card), we have to try again sometimes.
2056 	 */
2057 	reg_write(ohci, OHCI1394_HCControlSet,
2058 		  OHCI1394_HCControl_LPS |
2059 		  OHCI1394_HCControl_postedWriteEnable);
2060 	flush_writes(ohci);
2061 
2062 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2063 		msleep(50);
2064 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2065 		      OHCI1394_HCControl_LPS;
2066 	}
2067 
2068 	if (!lps) {
2069 		fw_error("Failed to set Link Power Status\n");
2070 		return -EIO;
2071 	}
2072 
2073 	reg_write(ohci, OHCI1394_HCControlClear,
2074 		  OHCI1394_HCControl_noByteSwapData);
2075 
2076 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2077 	reg_write(ohci, OHCI1394_LinkControlSet,
2078 		  OHCI1394_LinkControl_cycleTimerEnable |
2079 		  OHCI1394_LinkControl_cycleMaster);
2080 
2081 	reg_write(ohci, OHCI1394_ATRetries,
2082 		  OHCI1394_MAX_AT_REQ_RETRIES |
2083 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2084 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2085 		  (200 << 16));
2086 
2087 	seconds = lower_32_bits(get_seconds());
2088 	reg_write(ohci, OHCI1394_IsochronousCycleTimer, seconds << 25);
2089 	ohci->bus_time = seconds & ~0x3f;
2090 
2091 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2092 	if (version >= OHCI_VERSION_1_1) {
2093 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2094 			  0xfffffffe);
2095 		card->broadcast_channel_auto_allocated = true;
2096 	}
2097 
2098 	/* Get implemented bits of the priority arbitration request counter. */
2099 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2100 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2101 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2102 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2103 
2104 	reg_write(ohci, OHCI1394_PhyUpperBound, 0x00010000);
2105 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2106 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2107 
2108 	ret = configure_1394a_enhancements(ohci);
2109 	if (ret < 0)
2110 		return ret;
2111 
2112 	/* Activate link_on bit and contender bit in our self ID packets.*/
2113 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2114 	if (ret < 0)
2115 		return ret;
2116 
2117 	/*
2118 	 * When the link is not yet enabled, the atomic config rom
2119 	 * update mechanism described below in ohci_set_config_rom()
2120 	 * is not active.  We have to update ConfigRomHeader and
2121 	 * BusOptions manually, and the write to ConfigROMmap takes
2122 	 * effect immediately.  We tie this to the enabling of the
2123 	 * link, so we have a valid config rom before enabling - the
2124 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2125 	 * values before enabling.
2126 	 *
2127 	 * However, when the ConfigROMmap is written, some controllers
2128 	 * always read back quadlets 0 and 2 from the config rom to
2129 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2130 	 * They shouldn't do that in this initial case where the link
2131 	 * isn't enabled.  This means we have to use the same
2132 	 * workaround here, setting the bus header to 0 and then write
2133 	 * the right values in the bus reset tasklet.
2134 	 */
2135 
2136 	if (config_rom) {
2137 		ohci->next_config_rom =
2138 			dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2139 					   &ohci->next_config_rom_bus,
2140 					   GFP_KERNEL);
2141 		if (ohci->next_config_rom == NULL)
2142 			return -ENOMEM;
2143 
2144 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2145 	} else {
2146 		/*
2147 		 * In the suspend case, config_rom is NULL, which
2148 		 * means that we just reuse the old config rom.
2149 		 */
2150 		ohci->next_config_rom = ohci->config_rom;
2151 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2152 	}
2153 
2154 	ohci->next_header = ohci->next_config_rom[0];
2155 	ohci->next_config_rom[0] = 0;
2156 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2157 	reg_write(ohci, OHCI1394_BusOptions,
2158 		  be32_to_cpu(ohci->next_config_rom[2]));
2159 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2160 
2161 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2162 
2163 	if (!(ohci->quirks & QUIRK_NO_MSI))
2164 		pci_enable_msi(dev);
2165 	if (request_irq(dev->irq, irq_handler,
2166 			pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
2167 			ohci_driver_name, ohci)) {
2168 		fw_error("Failed to allocate interrupt %d.\n", dev->irq);
2169 		pci_disable_msi(dev);
2170 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2171 				  ohci->config_rom, ohci->config_rom_bus);
2172 		return -EIO;
2173 	}
2174 
2175 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2176 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2177 		OHCI1394_isochTx | OHCI1394_isochRx |
2178 		OHCI1394_postedWriteErr |
2179 		OHCI1394_selfIDComplete |
2180 		OHCI1394_regAccessFail |
2181 		OHCI1394_cycle64Seconds |
2182 		OHCI1394_cycleInconsistent |
2183 		OHCI1394_unrecoverableError |
2184 		OHCI1394_cycleTooLong |
2185 		OHCI1394_masterIntEnable;
2186 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2187 		irqs |= OHCI1394_busReset;
2188 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2189 
2190 	reg_write(ohci, OHCI1394_HCControlSet,
2191 		  OHCI1394_HCControl_linkEnable |
2192 		  OHCI1394_HCControl_BIBimageValid);
2193 
2194 	reg_write(ohci, OHCI1394_LinkControlSet,
2195 		  OHCI1394_LinkControl_rcvSelfID |
2196 		  OHCI1394_LinkControl_rcvPhyPkt);
2197 
2198 	ar_context_run(&ohci->ar_request_ctx);
2199 	ar_context_run(&ohci->ar_response_ctx); /* also flushes writes */
2200 
2201 	/* We are ready to go, reset bus to finish initialization. */
2202 	fw_schedule_bus_reset(&ohci->card, false, true);
2203 
2204 	return 0;
2205 }
2206 
2207 static int ohci_set_config_rom(struct fw_card *card,
2208 			       const __be32 *config_rom, size_t length)
2209 {
2210 	struct fw_ohci *ohci;
2211 	unsigned long flags;
2212 	__be32 *next_config_rom;
2213 	dma_addr_t uninitialized_var(next_config_rom_bus);
2214 
2215 	ohci = fw_ohci(card);
2216 
2217 	/*
2218 	 * When the OHCI controller is enabled, the config rom update
2219 	 * mechanism is a bit tricky, but easy enough to use.  See
2220 	 * section 5.5.6 in the OHCI specification.
2221 	 *
2222 	 * The OHCI controller caches the new config rom address in a
2223 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2224 	 * for the changes to take place.  When the bus reset is
2225 	 * detected, the controller loads the new values for the
2226 	 * ConfigRomHeader and BusOptions registers from the specified
2227 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2228 	 * shadow register. All automatically and atomically.
2229 	 *
2230 	 * Now, there's a twist to this story.  The automatic load of
2231 	 * ConfigRomHeader and BusOptions doesn't honor the
2232 	 * noByteSwapData bit, so with a be32 config rom, the
2233 	 * controller will load be32 values in to these registers
2234 	 * during the atomic update, even on litte endian
2235 	 * architectures.  The workaround we use is to put a 0 in the
2236 	 * header quadlet; 0 is endian agnostic and means that the
2237 	 * config rom isn't ready yet.  In the bus reset tasklet we
2238 	 * then set up the real values for the two registers.
2239 	 *
2240 	 * We use ohci->lock to avoid racing with the code that sets
2241 	 * ohci->next_config_rom to NULL (see bus_reset_tasklet).
2242 	 */
2243 
2244 	next_config_rom =
2245 		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2246 				   &next_config_rom_bus, GFP_KERNEL);
2247 	if (next_config_rom == NULL)
2248 		return -ENOMEM;
2249 
2250 	spin_lock_irqsave(&ohci->lock, flags);
2251 
2252 	/*
2253 	 * If there is not an already pending config_rom update,
2254 	 * push our new allocation into the ohci->next_config_rom
2255 	 * and then mark the local variable as null so that we
2256 	 * won't deallocate the new buffer.
2257 	 *
2258 	 * OTOH, if there is a pending config_rom update, just
2259 	 * use that buffer with the new config_rom data, and
2260 	 * let this routine free the unused DMA allocation.
2261 	 */
2262 
2263 	if (ohci->next_config_rom == NULL) {
2264 		ohci->next_config_rom = next_config_rom;
2265 		ohci->next_config_rom_bus = next_config_rom_bus;
2266 		next_config_rom = NULL;
2267 	}
2268 
2269 	copy_config_rom(ohci->next_config_rom, config_rom, length);
2270 
2271 	ohci->next_header = config_rom[0];
2272 	ohci->next_config_rom[0] = 0;
2273 
2274 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2275 
2276 	spin_unlock_irqrestore(&ohci->lock, flags);
2277 
2278 	/* If we didn't use the DMA allocation, delete it. */
2279 	if (next_config_rom != NULL)
2280 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2281 				  next_config_rom, next_config_rom_bus);
2282 
2283 	/*
2284 	 * Now initiate a bus reset to have the changes take
2285 	 * effect. We clean up the old config rom memory and DMA
2286 	 * mappings in the bus reset tasklet, since the OHCI
2287 	 * controller could need to access it before the bus reset
2288 	 * takes effect.
2289 	 */
2290 
2291 	fw_schedule_bus_reset(&ohci->card, true, true);
2292 
2293 	return 0;
2294 }
2295 
2296 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2297 {
2298 	struct fw_ohci *ohci = fw_ohci(card);
2299 
2300 	at_context_transmit(&ohci->at_request_ctx, packet);
2301 }
2302 
2303 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2304 {
2305 	struct fw_ohci *ohci = fw_ohci(card);
2306 
2307 	at_context_transmit(&ohci->at_response_ctx, packet);
2308 }
2309 
2310 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2311 {
2312 	struct fw_ohci *ohci = fw_ohci(card);
2313 	struct context *ctx = &ohci->at_request_ctx;
2314 	struct driver_data *driver_data = packet->driver_data;
2315 	int ret = -ENOENT;
2316 
2317 	tasklet_disable(&ctx->tasklet);
2318 
2319 	if (packet->ack != 0)
2320 		goto out;
2321 
2322 	if (packet->payload_mapped)
2323 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2324 				 packet->payload_length, DMA_TO_DEVICE);
2325 
2326 	log_ar_at_event('T', packet->speed, packet->header, 0x20);
2327 	driver_data->packet = NULL;
2328 	packet->ack = RCODE_CANCELLED;
2329 	packet->callback(packet, &ohci->card, packet->ack);
2330 	ret = 0;
2331  out:
2332 	tasklet_enable(&ctx->tasklet);
2333 
2334 	return ret;
2335 }
2336 
2337 static int ohci_enable_phys_dma(struct fw_card *card,
2338 				int node_id, int generation)
2339 {
2340 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
2341 	return 0;
2342 #else
2343 	struct fw_ohci *ohci = fw_ohci(card);
2344 	unsigned long flags;
2345 	int n, ret = 0;
2346 
2347 	/*
2348 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2349 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2350 	 */
2351 
2352 	spin_lock_irqsave(&ohci->lock, flags);
2353 
2354 	if (ohci->generation != generation) {
2355 		ret = -ESTALE;
2356 		goto out;
2357 	}
2358 
2359 	/*
2360 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2361 	 * enabled for _all_ nodes on remote buses.
2362 	 */
2363 
2364 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2365 	if (n < 32)
2366 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2367 	else
2368 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2369 
2370 	flush_writes(ohci);
2371  out:
2372 	spin_unlock_irqrestore(&ohci->lock, flags);
2373 
2374 	return ret;
2375 #endif /* CONFIG_FIREWIRE_OHCI_REMOTE_DMA */
2376 }
2377 
2378 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2379 {
2380 	struct fw_ohci *ohci = fw_ohci(card);
2381 	unsigned long flags;
2382 	u32 value;
2383 
2384 	switch (csr_offset) {
2385 	case CSR_STATE_CLEAR:
2386 	case CSR_STATE_SET:
2387 		if (ohci->is_root &&
2388 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2389 		     OHCI1394_LinkControl_cycleMaster))
2390 			value = CSR_STATE_BIT_CMSTR;
2391 		else
2392 			value = 0;
2393 		if (ohci->csr_state_setclear_abdicate)
2394 			value |= CSR_STATE_BIT_ABDICATE;
2395 
2396 		return value;
2397 
2398 	case CSR_NODE_IDS:
2399 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2400 
2401 	case CSR_CYCLE_TIME:
2402 		return get_cycle_time(ohci);
2403 
2404 	case CSR_BUS_TIME:
2405 		/*
2406 		 * We might be called just after the cycle timer has wrapped
2407 		 * around but just before the cycle64Seconds handler, so we
2408 		 * better check here, too, if the bus time needs to be updated.
2409 		 */
2410 		spin_lock_irqsave(&ohci->lock, flags);
2411 		value = update_bus_time(ohci);
2412 		spin_unlock_irqrestore(&ohci->lock, flags);
2413 		return value;
2414 
2415 	case CSR_BUSY_TIMEOUT:
2416 		value = reg_read(ohci, OHCI1394_ATRetries);
2417 		return (value >> 4) & 0x0ffff00f;
2418 
2419 	case CSR_PRIORITY_BUDGET:
2420 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2421 			(ohci->pri_req_max << 8);
2422 
2423 	default:
2424 		WARN_ON(1);
2425 		return 0;
2426 	}
2427 }
2428 
2429 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2430 {
2431 	struct fw_ohci *ohci = fw_ohci(card);
2432 	unsigned long flags;
2433 
2434 	switch (csr_offset) {
2435 	case CSR_STATE_CLEAR:
2436 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2437 			reg_write(ohci, OHCI1394_LinkControlClear,
2438 				  OHCI1394_LinkControl_cycleMaster);
2439 			flush_writes(ohci);
2440 		}
2441 		if (value & CSR_STATE_BIT_ABDICATE)
2442 			ohci->csr_state_setclear_abdicate = false;
2443 		break;
2444 
2445 	case CSR_STATE_SET:
2446 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2447 			reg_write(ohci, OHCI1394_LinkControlSet,
2448 				  OHCI1394_LinkControl_cycleMaster);
2449 			flush_writes(ohci);
2450 		}
2451 		if (value & CSR_STATE_BIT_ABDICATE)
2452 			ohci->csr_state_setclear_abdicate = true;
2453 		break;
2454 
2455 	case CSR_NODE_IDS:
2456 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2457 		flush_writes(ohci);
2458 		break;
2459 
2460 	case CSR_CYCLE_TIME:
2461 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2462 		reg_write(ohci, OHCI1394_IntEventSet,
2463 			  OHCI1394_cycleInconsistent);
2464 		flush_writes(ohci);
2465 		break;
2466 
2467 	case CSR_BUS_TIME:
2468 		spin_lock_irqsave(&ohci->lock, flags);
2469 		ohci->bus_time = (ohci->bus_time & 0x7f) | (value & ~0x7f);
2470 		spin_unlock_irqrestore(&ohci->lock, flags);
2471 		break;
2472 
2473 	case CSR_BUSY_TIMEOUT:
2474 		value = (value & 0xf) | ((value & 0xf) << 4) |
2475 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2476 		reg_write(ohci, OHCI1394_ATRetries, value);
2477 		flush_writes(ohci);
2478 		break;
2479 
2480 	case CSR_PRIORITY_BUDGET:
2481 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2482 		flush_writes(ohci);
2483 		break;
2484 
2485 	default:
2486 		WARN_ON(1);
2487 		break;
2488 	}
2489 }
2490 
2491 static void copy_iso_headers(struct iso_context *ctx, void *p)
2492 {
2493 	int i = ctx->header_length;
2494 
2495 	if (i + ctx->base.header_size > PAGE_SIZE)
2496 		return;
2497 
2498 	/*
2499 	 * The iso header is byteswapped to little endian by
2500 	 * the controller, but the remaining header quadlets
2501 	 * are big endian.  We want to present all the headers
2502 	 * as big endian, so we have to swap the first quadlet.
2503 	 */
2504 	if (ctx->base.header_size > 0)
2505 		*(u32 *) (ctx->header + i) = __swab32(*(u32 *) (p + 4));
2506 	if (ctx->base.header_size > 4)
2507 		*(u32 *) (ctx->header + i + 4) = __swab32(*(u32 *) p);
2508 	if (ctx->base.header_size > 8)
2509 		memcpy(ctx->header + i + 8, p + 8, ctx->base.header_size - 8);
2510 	ctx->header_length += ctx->base.header_size;
2511 }
2512 
2513 static int handle_ir_packet_per_buffer(struct context *context,
2514 				       struct descriptor *d,
2515 				       struct descriptor *last)
2516 {
2517 	struct iso_context *ctx =
2518 		container_of(context, struct iso_context, context);
2519 	struct descriptor *pd;
2520 	__le32 *ir_header;
2521 	void *p;
2522 
2523 	for (pd = d; pd <= last; pd++)
2524 		if (pd->transfer_status)
2525 			break;
2526 	if (pd > last)
2527 		/* Descriptor(s) not done yet, stop iteration */
2528 		return 0;
2529 
2530 	p = last + 1;
2531 	copy_iso_headers(ctx, p);
2532 
2533 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
2534 		ir_header = (__le32 *) p;
2535 		ctx->base.callback.sc(&ctx->base,
2536 				      le32_to_cpu(ir_header[0]) & 0xffff,
2537 				      ctx->header_length, ctx->header,
2538 				      ctx->base.callback_data);
2539 		ctx->header_length = 0;
2540 	}
2541 
2542 	return 1;
2543 }
2544 
2545 /* d == last because each descriptor block is only a single descriptor. */
2546 static int handle_ir_buffer_fill(struct context *context,
2547 				 struct descriptor *d,
2548 				 struct descriptor *last)
2549 {
2550 	struct iso_context *ctx =
2551 		container_of(context, struct iso_context, context);
2552 
2553 	if (!last->transfer_status)
2554 		/* Descriptor(s) not done yet, stop iteration */
2555 		return 0;
2556 
2557 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS)
2558 		ctx->base.callback.mc(&ctx->base,
2559 				      le32_to_cpu(last->data_address) +
2560 				      le16_to_cpu(last->req_count) -
2561 				      le16_to_cpu(last->res_count),
2562 				      ctx->base.callback_data);
2563 
2564 	return 1;
2565 }
2566 
2567 static int handle_it_packet(struct context *context,
2568 			    struct descriptor *d,
2569 			    struct descriptor *last)
2570 {
2571 	struct iso_context *ctx =
2572 		container_of(context, struct iso_context, context);
2573 	int i;
2574 	struct descriptor *pd;
2575 
2576 	for (pd = d; pd <= last; pd++)
2577 		if (pd->transfer_status)
2578 			break;
2579 	if (pd > last)
2580 		/* Descriptor(s) not done yet, stop iteration */
2581 		return 0;
2582 
2583 	i = ctx->header_length;
2584 	if (i + 4 < PAGE_SIZE) {
2585 		/* Present this value as big-endian to match the receive code */
2586 		*(__be32 *)(ctx->header + i) = cpu_to_be32(
2587 				((u32)le16_to_cpu(pd->transfer_status) << 16) |
2588 				le16_to_cpu(pd->res_count));
2589 		ctx->header_length += 4;
2590 	}
2591 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
2592 		ctx->base.callback.sc(&ctx->base, le16_to_cpu(last->res_count),
2593 				      ctx->header_length, ctx->header,
2594 				      ctx->base.callback_data);
2595 		ctx->header_length = 0;
2596 	}
2597 	return 1;
2598 }
2599 
2600 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2601 {
2602 	u32 hi = channels >> 32, lo = channels;
2603 
2604 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2605 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2606 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2607 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2608 	mmiowb();
2609 	ohci->mc_channels = channels;
2610 }
2611 
2612 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2613 				int type, int channel, size_t header_size)
2614 {
2615 	struct fw_ohci *ohci = fw_ohci(card);
2616 	struct iso_context *uninitialized_var(ctx);
2617 	descriptor_callback_t uninitialized_var(callback);
2618 	u64 *uninitialized_var(channels);
2619 	u32 *uninitialized_var(mask), uninitialized_var(regs);
2620 	unsigned long flags;
2621 	int index, ret = -EBUSY;
2622 
2623 	spin_lock_irqsave(&ohci->lock, flags);
2624 
2625 	switch (type) {
2626 	case FW_ISO_CONTEXT_TRANSMIT:
2627 		mask     = &ohci->it_context_mask;
2628 		callback = handle_it_packet;
2629 		index    = ffs(*mask) - 1;
2630 		if (index >= 0) {
2631 			*mask &= ~(1 << index);
2632 			regs = OHCI1394_IsoXmitContextBase(index);
2633 			ctx  = &ohci->it_context_list[index];
2634 		}
2635 		break;
2636 
2637 	case FW_ISO_CONTEXT_RECEIVE:
2638 		channels = &ohci->ir_context_channels;
2639 		mask     = &ohci->ir_context_mask;
2640 		callback = handle_ir_packet_per_buffer;
2641 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2642 		if (index >= 0) {
2643 			*channels &= ~(1ULL << channel);
2644 			*mask     &= ~(1 << index);
2645 			regs = OHCI1394_IsoRcvContextBase(index);
2646 			ctx  = &ohci->ir_context_list[index];
2647 		}
2648 		break;
2649 
2650 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2651 		mask     = &ohci->ir_context_mask;
2652 		callback = handle_ir_buffer_fill;
2653 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2654 		if (index >= 0) {
2655 			ohci->mc_allocated = true;
2656 			*mask &= ~(1 << index);
2657 			regs = OHCI1394_IsoRcvContextBase(index);
2658 			ctx  = &ohci->ir_context_list[index];
2659 		}
2660 		break;
2661 
2662 	default:
2663 		index = -1;
2664 		ret = -ENOSYS;
2665 	}
2666 
2667 	spin_unlock_irqrestore(&ohci->lock, flags);
2668 
2669 	if (index < 0)
2670 		return ERR_PTR(ret);
2671 
2672 	memset(ctx, 0, sizeof(*ctx));
2673 	ctx->header_length = 0;
2674 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
2675 	if (ctx->header == NULL) {
2676 		ret = -ENOMEM;
2677 		goto out;
2678 	}
2679 	ret = context_init(&ctx->context, ohci, regs, callback);
2680 	if (ret < 0)
2681 		goto out_with_header;
2682 
2683 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL)
2684 		set_multichannel_mask(ohci, 0);
2685 
2686 	return &ctx->base;
2687 
2688  out_with_header:
2689 	free_page((unsigned long)ctx->header);
2690  out:
2691 	spin_lock_irqsave(&ohci->lock, flags);
2692 
2693 	switch (type) {
2694 	case FW_ISO_CONTEXT_RECEIVE:
2695 		*channels |= 1ULL << channel;
2696 		break;
2697 
2698 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2699 		ohci->mc_allocated = false;
2700 		break;
2701 	}
2702 	*mask |= 1 << index;
2703 
2704 	spin_unlock_irqrestore(&ohci->lock, flags);
2705 
2706 	return ERR_PTR(ret);
2707 }
2708 
2709 static int ohci_start_iso(struct fw_iso_context *base,
2710 			  s32 cycle, u32 sync, u32 tags)
2711 {
2712 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2713 	struct fw_ohci *ohci = ctx->context.ohci;
2714 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
2715 	int index;
2716 
2717 	/* the controller cannot start without any queued packets */
2718 	if (ctx->context.last->branch_address == 0)
2719 		return -ENODATA;
2720 
2721 	switch (ctx->base.type) {
2722 	case FW_ISO_CONTEXT_TRANSMIT:
2723 		index = ctx - ohci->it_context_list;
2724 		match = 0;
2725 		if (cycle >= 0)
2726 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
2727 				(cycle & 0x7fff) << 16;
2728 
2729 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
2730 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
2731 		context_run(&ctx->context, match);
2732 		break;
2733 
2734 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2735 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
2736 		/* fall through */
2737 	case FW_ISO_CONTEXT_RECEIVE:
2738 		index = ctx - ohci->ir_context_list;
2739 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
2740 		if (cycle >= 0) {
2741 			match |= (cycle & 0x07fff) << 12;
2742 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
2743 		}
2744 
2745 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
2746 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
2747 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
2748 		context_run(&ctx->context, control);
2749 
2750 		ctx->sync = sync;
2751 		ctx->tags = tags;
2752 
2753 		break;
2754 	}
2755 
2756 	return 0;
2757 }
2758 
2759 static int ohci_stop_iso(struct fw_iso_context *base)
2760 {
2761 	struct fw_ohci *ohci = fw_ohci(base->card);
2762 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2763 	int index;
2764 
2765 	switch (ctx->base.type) {
2766 	case FW_ISO_CONTEXT_TRANSMIT:
2767 		index = ctx - ohci->it_context_list;
2768 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
2769 		break;
2770 
2771 	case FW_ISO_CONTEXT_RECEIVE:
2772 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2773 		index = ctx - ohci->ir_context_list;
2774 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
2775 		break;
2776 	}
2777 	flush_writes(ohci);
2778 	context_stop(&ctx->context);
2779 	tasklet_kill(&ctx->context.tasklet);
2780 
2781 	return 0;
2782 }
2783 
2784 static void ohci_free_iso_context(struct fw_iso_context *base)
2785 {
2786 	struct fw_ohci *ohci = fw_ohci(base->card);
2787 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2788 	unsigned long flags;
2789 	int index;
2790 
2791 	ohci_stop_iso(base);
2792 	context_release(&ctx->context);
2793 	free_page((unsigned long)ctx->header);
2794 
2795 	spin_lock_irqsave(&ohci->lock, flags);
2796 
2797 	switch (base->type) {
2798 	case FW_ISO_CONTEXT_TRANSMIT:
2799 		index = ctx - ohci->it_context_list;
2800 		ohci->it_context_mask |= 1 << index;
2801 		break;
2802 
2803 	case FW_ISO_CONTEXT_RECEIVE:
2804 		index = ctx - ohci->ir_context_list;
2805 		ohci->ir_context_mask |= 1 << index;
2806 		ohci->ir_context_channels |= 1ULL << base->channel;
2807 		break;
2808 
2809 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2810 		index = ctx - ohci->ir_context_list;
2811 		ohci->ir_context_mask |= 1 << index;
2812 		ohci->ir_context_channels |= ohci->mc_channels;
2813 		ohci->mc_channels = 0;
2814 		ohci->mc_allocated = false;
2815 		break;
2816 	}
2817 
2818 	spin_unlock_irqrestore(&ohci->lock, flags);
2819 }
2820 
2821 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
2822 {
2823 	struct fw_ohci *ohci = fw_ohci(base->card);
2824 	unsigned long flags;
2825 	int ret;
2826 
2827 	switch (base->type) {
2828 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2829 
2830 		spin_lock_irqsave(&ohci->lock, flags);
2831 
2832 		/* Don't allow multichannel to grab other contexts' channels. */
2833 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
2834 			*channels = ohci->ir_context_channels;
2835 			ret = -EBUSY;
2836 		} else {
2837 			set_multichannel_mask(ohci, *channels);
2838 			ret = 0;
2839 		}
2840 
2841 		spin_unlock_irqrestore(&ohci->lock, flags);
2842 
2843 		break;
2844 	default:
2845 		ret = -EINVAL;
2846 	}
2847 
2848 	return ret;
2849 }
2850 
2851 #ifdef CONFIG_PM
2852 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
2853 {
2854 	int i;
2855 	struct iso_context *ctx;
2856 
2857 	for (i = 0 ; i < ohci->n_ir ; i++) {
2858 		ctx = &ohci->ir_context_list[i];
2859 		if (ctx->context.running)
2860 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
2861 	}
2862 
2863 	for (i = 0 ; i < ohci->n_it ; i++) {
2864 		ctx = &ohci->it_context_list[i];
2865 		if (ctx->context.running)
2866 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
2867 	}
2868 }
2869 #endif
2870 
2871 static int queue_iso_transmit(struct iso_context *ctx,
2872 			      struct fw_iso_packet *packet,
2873 			      struct fw_iso_buffer *buffer,
2874 			      unsigned long payload)
2875 {
2876 	struct descriptor *d, *last, *pd;
2877 	struct fw_iso_packet *p;
2878 	__le32 *header;
2879 	dma_addr_t d_bus, page_bus;
2880 	u32 z, header_z, payload_z, irq;
2881 	u32 payload_index, payload_end_index, next_page_index;
2882 	int page, end_page, i, length, offset;
2883 
2884 	p = packet;
2885 	payload_index = payload;
2886 
2887 	if (p->skip)
2888 		z = 1;
2889 	else
2890 		z = 2;
2891 	if (p->header_length > 0)
2892 		z++;
2893 
2894 	/* Determine the first page the payload isn't contained in. */
2895 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
2896 	if (p->payload_length > 0)
2897 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
2898 	else
2899 		payload_z = 0;
2900 
2901 	z += payload_z;
2902 
2903 	/* Get header size in number of descriptors. */
2904 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
2905 
2906 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
2907 	if (d == NULL)
2908 		return -ENOMEM;
2909 
2910 	if (!p->skip) {
2911 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
2912 		d[0].req_count = cpu_to_le16(8);
2913 		/*
2914 		 * Link the skip address to this descriptor itself.  This causes
2915 		 * a context to skip a cycle whenever lost cycles or FIFO
2916 		 * overruns occur, without dropping the data.  The application
2917 		 * should then decide whether this is an error condition or not.
2918 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
2919 		 */
2920 		d[0].branch_address = cpu_to_le32(d_bus | z);
2921 
2922 		header = (__le32 *) &d[1];
2923 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
2924 					IT_HEADER_TAG(p->tag) |
2925 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
2926 					IT_HEADER_CHANNEL(ctx->base.channel) |
2927 					IT_HEADER_SPEED(ctx->base.speed));
2928 		header[1] =
2929 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
2930 							  p->payload_length));
2931 	}
2932 
2933 	if (p->header_length > 0) {
2934 		d[2].req_count    = cpu_to_le16(p->header_length);
2935 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
2936 		memcpy(&d[z], p->header, p->header_length);
2937 	}
2938 
2939 	pd = d + z - payload_z;
2940 	payload_end_index = payload_index + p->payload_length;
2941 	for (i = 0; i < payload_z; i++) {
2942 		page               = payload_index >> PAGE_SHIFT;
2943 		offset             = payload_index & ~PAGE_MASK;
2944 		next_page_index    = (page + 1) << PAGE_SHIFT;
2945 		length             =
2946 			min(next_page_index, payload_end_index) - payload_index;
2947 		pd[i].req_count    = cpu_to_le16(length);
2948 
2949 		page_bus = page_private(buffer->pages[page]);
2950 		pd[i].data_address = cpu_to_le32(page_bus + offset);
2951 
2952 		payload_index += length;
2953 	}
2954 
2955 	if (p->interrupt)
2956 		irq = DESCRIPTOR_IRQ_ALWAYS;
2957 	else
2958 		irq = DESCRIPTOR_NO_IRQ;
2959 
2960 	last = z == 2 ? d : d + z - 1;
2961 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
2962 				     DESCRIPTOR_STATUS |
2963 				     DESCRIPTOR_BRANCH_ALWAYS |
2964 				     irq);
2965 
2966 	context_append(&ctx->context, d, z, header_z);
2967 
2968 	return 0;
2969 }
2970 
2971 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
2972 				       struct fw_iso_packet *packet,
2973 				       struct fw_iso_buffer *buffer,
2974 				       unsigned long payload)
2975 {
2976 	struct descriptor *d, *pd;
2977 	dma_addr_t d_bus, page_bus;
2978 	u32 z, header_z, rest;
2979 	int i, j, length;
2980 	int page, offset, packet_count, header_size, payload_per_buffer;
2981 
2982 	/*
2983 	 * The OHCI controller puts the isochronous header and trailer in the
2984 	 * buffer, so we need at least 8 bytes.
2985 	 */
2986 	packet_count = packet->header_length / ctx->base.header_size;
2987 	header_size  = max(ctx->base.header_size, (size_t)8);
2988 
2989 	/* Get header size in number of descriptors. */
2990 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
2991 	page     = payload >> PAGE_SHIFT;
2992 	offset   = payload & ~PAGE_MASK;
2993 	payload_per_buffer = packet->payload_length / packet_count;
2994 
2995 	for (i = 0; i < packet_count; i++) {
2996 		/* d points to the header descriptor */
2997 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
2998 		d = context_get_descriptors(&ctx->context,
2999 				z + header_z, &d_bus);
3000 		if (d == NULL)
3001 			return -ENOMEM;
3002 
3003 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3004 					      DESCRIPTOR_INPUT_MORE);
3005 		if (packet->skip && i == 0)
3006 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3007 		d->req_count    = cpu_to_le16(header_size);
3008 		d->res_count    = d->req_count;
3009 		d->transfer_status = 0;
3010 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3011 
3012 		rest = payload_per_buffer;
3013 		pd = d;
3014 		for (j = 1; j < z; j++) {
3015 			pd++;
3016 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3017 						  DESCRIPTOR_INPUT_MORE);
3018 
3019 			if (offset + rest < PAGE_SIZE)
3020 				length = rest;
3021 			else
3022 				length = PAGE_SIZE - offset;
3023 			pd->req_count = cpu_to_le16(length);
3024 			pd->res_count = pd->req_count;
3025 			pd->transfer_status = 0;
3026 
3027 			page_bus = page_private(buffer->pages[page]);
3028 			pd->data_address = cpu_to_le32(page_bus + offset);
3029 
3030 			offset = (offset + length) & ~PAGE_MASK;
3031 			rest -= length;
3032 			if (offset == 0)
3033 				page++;
3034 		}
3035 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3036 					  DESCRIPTOR_INPUT_LAST |
3037 					  DESCRIPTOR_BRANCH_ALWAYS);
3038 		if (packet->interrupt && i == packet_count - 1)
3039 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3040 
3041 		context_append(&ctx->context, d, z, header_z);
3042 	}
3043 
3044 	return 0;
3045 }
3046 
3047 static int queue_iso_buffer_fill(struct iso_context *ctx,
3048 				 struct fw_iso_packet *packet,
3049 				 struct fw_iso_buffer *buffer,
3050 				 unsigned long payload)
3051 {
3052 	struct descriptor *d;
3053 	dma_addr_t d_bus, page_bus;
3054 	int page, offset, rest, z, i, length;
3055 
3056 	page   = payload >> PAGE_SHIFT;
3057 	offset = payload & ~PAGE_MASK;
3058 	rest   = packet->payload_length;
3059 
3060 	/* We need one descriptor for each page in the buffer. */
3061 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3062 
3063 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3064 		return -EFAULT;
3065 
3066 	for (i = 0; i < z; i++) {
3067 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3068 		if (d == NULL)
3069 			return -ENOMEM;
3070 
3071 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3072 					 DESCRIPTOR_BRANCH_ALWAYS);
3073 		if (packet->skip && i == 0)
3074 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3075 		if (packet->interrupt && i == z - 1)
3076 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3077 
3078 		if (offset + rest < PAGE_SIZE)
3079 			length = rest;
3080 		else
3081 			length = PAGE_SIZE - offset;
3082 		d->req_count = cpu_to_le16(length);
3083 		d->res_count = d->req_count;
3084 		d->transfer_status = 0;
3085 
3086 		page_bus = page_private(buffer->pages[page]);
3087 		d->data_address = cpu_to_le32(page_bus + offset);
3088 
3089 		rest -= length;
3090 		offset = 0;
3091 		page++;
3092 
3093 		context_append(&ctx->context, d, 1, 0);
3094 	}
3095 
3096 	return 0;
3097 }
3098 
3099 static int ohci_queue_iso(struct fw_iso_context *base,
3100 			  struct fw_iso_packet *packet,
3101 			  struct fw_iso_buffer *buffer,
3102 			  unsigned long payload)
3103 {
3104 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3105 	unsigned long flags;
3106 	int ret = -ENOSYS;
3107 
3108 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3109 	switch (base->type) {
3110 	case FW_ISO_CONTEXT_TRANSMIT:
3111 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3112 		break;
3113 	case FW_ISO_CONTEXT_RECEIVE:
3114 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3115 		break;
3116 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3117 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3118 		break;
3119 	}
3120 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3121 
3122 	return ret;
3123 }
3124 
3125 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3126 {
3127 	struct context *ctx =
3128 			&container_of(base, struct iso_context, base)->context;
3129 
3130 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3131 	flush_writes(ctx->ohci);
3132 }
3133 
3134 static const struct fw_card_driver ohci_driver = {
3135 	.enable			= ohci_enable,
3136 	.read_phy_reg		= ohci_read_phy_reg,
3137 	.update_phy_reg		= ohci_update_phy_reg,
3138 	.set_config_rom		= ohci_set_config_rom,
3139 	.send_request		= ohci_send_request,
3140 	.send_response		= ohci_send_response,
3141 	.cancel_packet		= ohci_cancel_packet,
3142 	.enable_phys_dma	= ohci_enable_phys_dma,
3143 	.read_csr		= ohci_read_csr,
3144 	.write_csr		= ohci_write_csr,
3145 
3146 	.allocate_iso_context	= ohci_allocate_iso_context,
3147 	.free_iso_context	= ohci_free_iso_context,
3148 	.set_iso_channels	= ohci_set_iso_channels,
3149 	.queue_iso		= ohci_queue_iso,
3150 	.flush_queue_iso	= ohci_flush_queue_iso,
3151 	.start_iso		= ohci_start_iso,
3152 	.stop_iso		= ohci_stop_iso,
3153 };
3154 
3155 #ifdef CONFIG_PPC_PMAC
3156 static void pmac_ohci_on(struct pci_dev *dev)
3157 {
3158 	if (machine_is(powermac)) {
3159 		struct device_node *ofn = pci_device_to_OF_node(dev);
3160 
3161 		if (ofn) {
3162 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3163 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3164 		}
3165 	}
3166 }
3167 
3168 static void pmac_ohci_off(struct pci_dev *dev)
3169 {
3170 	if (machine_is(powermac)) {
3171 		struct device_node *ofn = pci_device_to_OF_node(dev);
3172 
3173 		if (ofn) {
3174 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3175 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3176 		}
3177 	}
3178 }
3179 #else
3180 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3181 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3182 #endif /* CONFIG_PPC_PMAC */
3183 
3184 static int __devinit pci_probe(struct pci_dev *dev,
3185 			       const struct pci_device_id *ent)
3186 {
3187 	struct fw_ohci *ohci;
3188 	u32 bus_options, max_receive, link_speed, version;
3189 	u64 guid;
3190 	int i, err;
3191 	size_t size;
3192 
3193 	ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3194 	if (ohci == NULL) {
3195 		err = -ENOMEM;
3196 		goto fail;
3197 	}
3198 
3199 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3200 
3201 	pmac_ohci_on(dev);
3202 
3203 	err = pci_enable_device(dev);
3204 	if (err) {
3205 		fw_error("Failed to enable OHCI hardware\n");
3206 		goto fail_free;
3207 	}
3208 
3209 	pci_set_master(dev);
3210 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3211 	pci_set_drvdata(dev, ohci);
3212 
3213 	spin_lock_init(&ohci->lock);
3214 	mutex_init(&ohci->phy_reg_mutex);
3215 
3216 	tasklet_init(&ohci->bus_reset_tasklet,
3217 		     bus_reset_tasklet, (unsigned long)ohci);
3218 
3219 	err = pci_request_region(dev, 0, ohci_driver_name);
3220 	if (err) {
3221 		fw_error("MMIO resource unavailable\n");
3222 		goto fail_disable;
3223 	}
3224 
3225 	ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3226 	if (ohci->registers == NULL) {
3227 		fw_error("Failed to remap registers\n");
3228 		err = -ENXIO;
3229 		goto fail_iomem;
3230 	}
3231 
3232 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3233 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3234 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3235 		     ohci_quirks[i].device == dev->device) &&
3236 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3237 		     ohci_quirks[i].revision >= dev->revision)) {
3238 			ohci->quirks = ohci_quirks[i].flags;
3239 			break;
3240 		}
3241 	if (param_quirks)
3242 		ohci->quirks = param_quirks;
3243 
3244 	/*
3245 	 * Because dma_alloc_coherent() allocates at least one page,
3246 	 * we save space by using a common buffer for the AR request/
3247 	 * response descriptors and the self IDs buffer.
3248 	 */
3249 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3250 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3251 	ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3252 					       PAGE_SIZE,
3253 					       &ohci->misc_buffer_bus,
3254 					       GFP_KERNEL);
3255 	if (!ohci->misc_buffer) {
3256 		err = -ENOMEM;
3257 		goto fail_iounmap;
3258 	}
3259 
3260 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3261 			      OHCI1394_AsReqRcvContextControlSet);
3262 	if (err < 0)
3263 		goto fail_misc_buf;
3264 
3265 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3266 			      OHCI1394_AsRspRcvContextControlSet);
3267 	if (err < 0)
3268 		goto fail_arreq_ctx;
3269 
3270 	err = context_init(&ohci->at_request_ctx, ohci,
3271 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3272 	if (err < 0)
3273 		goto fail_arrsp_ctx;
3274 
3275 	err = context_init(&ohci->at_response_ctx, ohci,
3276 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3277 	if (err < 0)
3278 		goto fail_atreq_ctx;
3279 
3280 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3281 	ohci->ir_context_channels = ~0ULL;
3282 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3283 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3284 	ohci->ir_context_mask = ohci->ir_context_support;
3285 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3286 	size = sizeof(struct iso_context) * ohci->n_ir;
3287 	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3288 
3289 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3290 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3291 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3292 	ohci->it_context_mask = ohci->it_context_support;
3293 	ohci->n_it = hweight32(ohci->it_context_mask);
3294 	size = sizeof(struct iso_context) * ohci->n_it;
3295 	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3296 
3297 	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3298 		err = -ENOMEM;
3299 		goto fail_contexts;
3300 	}
3301 
3302 	ohci->self_id_cpu = ohci->misc_buffer     + PAGE_SIZE/2;
3303 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3304 
3305 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3306 	max_receive = (bus_options >> 12) & 0xf;
3307 	link_speed = bus_options & 0x7;
3308 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3309 		reg_read(ohci, OHCI1394_GUIDLo);
3310 
3311 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3312 	if (err)
3313 		goto fail_contexts;
3314 
3315 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3316 	fw_notify("Added fw-ohci device %s, OHCI v%x.%x, "
3317 		  "%d IR + %d IT contexts, quirks 0x%x\n",
3318 		  dev_name(&dev->dev), version >> 16, version & 0xff,
3319 		  ohci->n_ir, ohci->n_it, ohci->quirks);
3320 
3321 	return 0;
3322 
3323  fail_contexts:
3324 	kfree(ohci->ir_context_list);
3325 	kfree(ohci->it_context_list);
3326 	context_release(&ohci->at_response_ctx);
3327  fail_atreq_ctx:
3328 	context_release(&ohci->at_request_ctx);
3329  fail_arrsp_ctx:
3330 	ar_context_release(&ohci->ar_response_ctx);
3331  fail_arreq_ctx:
3332 	ar_context_release(&ohci->ar_request_ctx);
3333  fail_misc_buf:
3334 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3335 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3336  fail_iounmap:
3337 	pci_iounmap(dev, ohci->registers);
3338  fail_iomem:
3339 	pci_release_region(dev, 0);
3340  fail_disable:
3341 	pci_disable_device(dev);
3342  fail_free:
3343 	kfree(ohci);
3344 	pmac_ohci_off(dev);
3345  fail:
3346 	if (err == -ENOMEM)
3347 		fw_error("Out of memory\n");
3348 
3349 	return err;
3350 }
3351 
3352 static void pci_remove(struct pci_dev *dev)
3353 {
3354 	struct fw_ohci *ohci;
3355 
3356 	ohci = pci_get_drvdata(dev);
3357 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3358 	flush_writes(ohci);
3359 	fw_core_remove_card(&ohci->card);
3360 
3361 	/*
3362 	 * FIXME: Fail all pending packets here, now that the upper
3363 	 * layers can't queue any more.
3364 	 */
3365 
3366 	software_reset(ohci);
3367 	free_irq(dev->irq, ohci);
3368 
3369 	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3370 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3371 				  ohci->next_config_rom, ohci->next_config_rom_bus);
3372 	if (ohci->config_rom)
3373 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3374 				  ohci->config_rom, ohci->config_rom_bus);
3375 	ar_context_release(&ohci->ar_request_ctx);
3376 	ar_context_release(&ohci->ar_response_ctx);
3377 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3378 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3379 	context_release(&ohci->at_request_ctx);
3380 	context_release(&ohci->at_response_ctx);
3381 	kfree(ohci->it_context_list);
3382 	kfree(ohci->ir_context_list);
3383 	pci_disable_msi(dev);
3384 	pci_iounmap(dev, ohci->registers);
3385 	pci_release_region(dev, 0);
3386 	pci_disable_device(dev);
3387 	kfree(ohci);
3388 	pmac_ohci_off(dev);
3389 
3390 	fw_notify("Removed fw-ohci device.\n");
3391 }
3392 
3393 #ifdef CONFIG_PM
3394 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3395 {
3396 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3397 	int err;
3398 
3399 	software_reset(ohci);
3400 	free_irq(dev->irq, ohci);
3401 	pci_disable_msi(dev);
3402 	err = pci_save_state(dev);
3403 	if (err) {
3404 		fw_error("pci_save_state failed\n");
3405 		return err;
3406 	}
3407 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3408 	if (err)
3409 		fw_error("pci_set_power_state failed with %d\n", err);
3410 	pmac_ohci_off(dev);
3411 
3412 	return 0;
3413 }
3414 
3415 static int pci_resume(struct pci_dev *dev)
3416 {
3417 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3418 	int err;
3419 
3420 	pmac_ohci_on(dev);
3421 	pci_set_power_state(dev, PCI_D0);
3422 	pci_restore_state(dev);
3423 	err = pci_enable_device(dev);
3424 	if (err) {
3425 		fw_error("pci_enable_device failed\n");
3426 		return err;
3427 	}
3428 
3429 	/* Some systems don't setup GUID register on resume from ram  */
3430 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3431 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3432 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3433 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3434 	}
3435 
3436 	err = ohci_enable(&ohci->card, NULL, 0);
3437 	if (err)
3438 		return err;
3439 
3440 	ohci_resume_iso_dma(ohci);
3441 
3442 	return 0;
3443 }
3444 #endif
3445 
3446 static const struct pci_device_id pci_table[] = {
3447 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3448 	{ }
3449 };
3450 
3451 MODULE_DEVICE_TABLE(pci, pci_table);
3452 
3453 static struct pci_driver fw_ohci_pci_driver = {
3454 	.name		= ohci_driver_name,
3455 	.id_table	= pci_table,
3456 	.probe		= pci_probe,
3457 	.remove		= pci_remove,
3458 #ifdef CONFIG_PM
3459 	.resume		= pci_resume,
3460 	.suspend	= pci_suspend,
3461 #endif
3462 };
3463 
3464 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3465 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3466 MODULE_LICENSE("GPL");
3467 
3468 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3469 #ifndef CONFIG_IEEE1394_OHCI1394_MODULE
3470 MODULE_ALIAS("ohci1394");
3471 #endif
3472 
3473 static int __init fw_ohci_init(void)
3474 {
3475 	return pci_register_driver(&fw_ohci_pci_driver);
3476 }
3477 
3478 static void __exit fw_ohci_cleanup(void)
3479 {
3480 	pci_unregister_driver(&fw_ohci_pci_driver);
3481 }
3482 
3483 module_init(fw_ohci_init);
3484 module_exit(fw_ohci_cleanup);
3485