xref: /openbmc/linux/drivers/firewire/ohci.c (revision 5bd8e16d)
1 /*
2  * Driver for OHCI 1394 controllers
3  *
4  * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 #include <linux/bitops.h>
22 #include <linux/bug.h>
23 #include <linux/compiler.h>
24 #include <linux/delay.h>
25 #include <linux/device.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/firewire.h>
28 #include <linux/firewire-constants.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/io.h>
32 #include <linux/kernel.h>
33 #include <linux/list.h>
34 #include <linux/mm.h>
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/mutex.h>
38 #include <linux/pci.h>
39 #include <linux/pci_ids.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/string.h>
43 #include <linux/time.h>
44 #include <linux/vmalloc.h>
45 #include <linux/workqueue.h>
46 
47 #include <asm/byteorder.h>
48 #include <asm/page.h>
49 
50 #ifdef CONFIG_PPC_PMAC
51 #include <asm/pmac_feature.h>
52 #endif
53 
54 #include "core.h"
55 #include "ohci.h"
56 
57 #define ohci_info(ohci, f, args...)	dev_info(ohci->card.device, f, ##args)
58 #define ohci_notice(ohci, f, args...)	dev_notice(ohci->card.device, f, ##args)
59 #define ohci_err(ohci, f, args...)	dev_err(ohci->card.device, f, ##args)
60 
61 #define DESCRIPTOR_OUTPUT_MORE		0
62 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
63 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
64 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
65 #define DESCRIPTOR_STATUS		(1 << 11)
66 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
67 #define DESCRIPTOR_PING			(1 << 7)
68 #define DESCRIPTOR_YY			(1 << 6)
69 #define DESCRIPTOR_NO_IRQ		(0 << 4)
70 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
71 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
72 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
73 #define DESCRIPTOR_WAIT			(3 << 0)
74 
75 #define DESCRIPTOR_CMD			(0xf << 12)
76 
77 struct descriptor {
78 	__le16 req_count;
79 	__le16 control;
80 	__le32 data_address;
81 	__le32 branch_address;
82 	__le16 res_count;
83 	__le16 transfer_status;
84 } __attribute__((aligned(16)));
85 
86 #define CONTROL_SET(regs)	(regs)
87 #define CONTROL_CLEAR(regs)	((regs) + 4)
88 #define COMMAND_PTR(regs)	((regs) + 12)
89 #define CONTEXT_MATCH(regs)	((regs) + 16)
90 
91 #define AR_BUFFER_SIZE	(32*1024)
92 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
93 /* we need at least two pages for proper list management */
94 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
95 
96 #define MAX_ASYNC_PAYLOAD	4096
97 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
98 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
99 
100 struct ar_context {
101 	struct fw_ohci *ohci;
102 	struct page *pages[AR_BUFFERS];
103 	void *buffer;
104 	struct descriptor *descriptors;
105 	dma_addr_t descriptors_bus;
106 	void *pointer;
107 	unsigned int last_buffer_index;
108 	u32 regs;
109 	struct tasklet_struct tasklet;
110 };
111 
112 struct context;
113 
114 typedef int (*descriptor_callback_t)(struct context *ctx,
115 				     struct descriptor *d,
116 				     struct descriptor *last);
117 
118 /*
119  * A buffer that contains a block of DMA-able coherent memory used for
120  * storing a portion of a DMA descriptor program.
121  */
122 struct descriptor_buffer {
123 	struct list_head list;
124 	dma_addr_t buffer_bus;
125 	size_t buffer_size;
126 	size_t used;
127 	struct descriptor buffer[0];
128 };
129 
130 struct context {
131 	struct fw_ohci *ohci;
132 	u32 regs;
133 	int total_allocation;
134 	u32 current_bus;
135 	bool running;
136 	bool flushing;
137 
138 	/*
139 	 * List of page-sized buffers for storing DMA descriptors.
140 	 * Head of list contains buffers in use and tail of list contains
141 	 * free buffers.
142 	 */
143 	struct list_head buffer_list;
144 
145 	/*
146 	 * Pointer to a buffer inside buffer_list that contains the tail
147 	 * end of the current DMA program.
148 	 */
149 	struct descriptor_buffer *buffer_tail;
150 
151 	/*
152 	 * The descriptor containing the branch address of the first
153 	 * descriptor that has not yet been filled by the device.
154 	 */
155 	struct descriptor *last;
156 
157 	/*
158 	 * The last descriptor block in the DMA program. It contains the branch
159 	 * address that must be updated upon appending a new descriptor.
160 	 */
161 	struct descriptor *prev;
162 	int prev_z;
163 
164 	descriptor_callback_t callback;
165 
166 	struct tasklet_struct tasklet;
167 };
168 
169 #define IT_HEADER_SY(v)          ((v) <<  0)
170 #define IT_HEADER_TCODE(v)       ((v) <<  4)
171 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
172 #define IT_HEADER_TAG(v)         ((v) << 14)
173 #define IT_HEADER_SPEED(v)       ((v) << 16)
174 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
175 
176 struct iso_context {
177 	struct fw_iso_context base;
178 	struct context context;
179 	void *header;
180 	size_t header_length;
181 	unsigned long flushing_completions;
182 	u32 mc_buffer_bus;
183 	u16 mc_completed;
184 	u16 last_timestamp;
185 	u8 sync;
186 	u8 tags;
187 };
188 
189 #define CONFIG_ROM_SIZE 1024
190 
191 struct fw_ohci {
192 	struct fw_card card;
193 
194 	__iomem char *registers;
195 	int node_id;
196 	int generation;
197 	int request_generation;	/* for timestamping incoming requests */
198 	unsigned quirks;
199 	unsigned int pri_req_max;
200 	u32 bus_time;
201 	bool bus_time_running;
202 	bool is_root;
203 	bool csr_state_setclear_abdicate;
204 	int n_ir;
205 	int n_it;
206 	/*
207 	 * Spinlock for accessing fw_ohci data.  Never call out of
208 	 * this driver with this lock held.
209 	 */
210 	spinlock_t lock;
211 
212 	struct mutex phy_reg_mutex;
213 
214 	void *misc_buffer;
215 	dma_addr_t misc_buffer_bus;
216 
217 	struct ar_context ar_request_ctx;
218 	struct ar_context ar_response_ctx;
219 	struct context at_request_ctx;
220 	struct context at_response_ctx;
221 
222 	u32 it_context_support;
223 	u32 it_context_mask;     /* unoccupied IT contexts */
224 	struct iso_context *it_context_list;
225 	u64 ir_context_channels; /* unoccupied channels */
226 	u32 ir_context_support;
227 	u32 ir_context_mask;     /* unoccupied IR contexts */
228 	struct iso_context *ir_context_list;
229 	u64 mc_channels; /* channels in use by the multichannel IR context */
230 	bool mc_allocated;
231 
232 	__be32    *config_rom;
233 	dma_addr_t config_rom_bus;
234 	__be32    *next_config_rom;
235 	dma_addr_t next_config_rom_bus;
236 	__be32     next_header;
237 
238 	__le32    *self_id;
239 	dma_addr_t self_id_bus;
240 	struct work_struct bus_reset_work;
241 
242 	u32 self_id_buffer[512];
243 };
244 
245 static struct workqueue_struct *selfid_workqueue;
246 
247 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
248 {
249 	return container_of(card, struct fw_ohci, card);
250 }
251 
252 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
253 #define IR_CONTEXT_BUFFER_FILL		0x80000000
254 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
255 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
256 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
257 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
258 
259 #define CONTEXT_RUN	0x8000
260 #define CONTEXT_WAKE	0x1000
261 #define CONTEXT_DEAD	0x0800
262 #define CONTEXT_ACTIVE	0x0400
263 
264 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
265 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
266 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
267 
268 #define OHCI1394_REGISTER_SIZE		0x800
269 #define OHCI1394_PCI_HCI_Control	0x40
270 #define SELF_ID_BUF_SIZE		0x800
271 #define OHCI_TCODE_PHY_PACKET		0x0e
272 #define OHCI_VERSION_1_1		0x010010
273 
274 static char ohci_driver_name[] = KBUILD_MODNAME;
275 
276 #define PCI_VENDOR_ID_PINNACLE_SYSTEMS	0x11bd
277 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
278 #define PCI_DEVICE_ID_CREATIVE_SB1394	0x4001
279 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
280 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
281 #define PCI_DEVICE_ID_TI_TSB12LV26	0x8020
282 #define PCI_DEVICE_ID_TI_TSB82AA2	0x8025
283 #define PCI_DEVICE_ID_VIA_VT630X	0x3044
284 #define PCI_REV_ID_VIA_VT6306		0x46
285 
286 #define QUIRK_CYCLE_TIMER		0x1
287 #define QUIRK_RESET_PACKET		0x2
288 #define QUIRK_BE_HEADERS		0x4
289 #define QUIRK_NO_1394A			0x8
290 #define QUIRK_NO_MSI			0x10
291 #define QUIRK_TI_SLLZ059		0x20
292 #define QUIRK_IR_WAKE			0x40
293 #define QUIRK_PHY_LCTRL_TIMEOUT		0x80
294 
295 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
296 static const struct {
297 	unsigned short vendor, device, revision, flags;
298 } ohci_quirks[] = {
299 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
300 		QUIRK_CYCLE_TIMER},
301 
302 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
303 		QUIRK_BE_HEADERS},
304 
305 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
306 		QUIRK_PHY_LCTRL_TIMEOUT | QUIRK_NO_MSI},
307 
308 	{PCI_VENDOR_ID_ATT, PCI_ANY_ID, PCI_ANY_ID,
309 		QUIRK_PHY_LCTRL_TIMEOUT},
310 
311 	{PCI_VENDOR_ID_CREATIVE, PCI_DEVICE_ID_CREATIVE_SB1394, PCI_ANY_ID,
312 		QUIRK_RESET_PACKET},
313 
314 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
315 		QUIRK_NO_MSI},
316 
317 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
318 		QUIRK_CYCLE_TIMER},
319 
320 	{PCI_VENDOR_ID_O2, PCI_ANY_ID, PCI_ANY_ID,
321 		QUIRK_NO_MSI},
322 
323 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
324 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
325 
326 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
327 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
328 
329 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV26, PCI_ANY_ID,
330 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
331 
332 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB82AA2, PCI_ANY_ID,
333 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
334 
335 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
336 		QUIRK_RESET_PACKET},
337 
338 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT630X, PCI_REV_ID_VIA_VT6306,
339 		QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE},
340 
341 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
342 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
343 };
344 
345 /* This overrides anything that was found in ohci_quirks[]. */
346 static int param_quirks;
347 module_param_named(quirks, param_quirks, int, 0644);
348 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
349 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
350 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
351 	", AR/selfID endianness = "	__stringify(QUIRK_BE_HEADERS)
352 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
353 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
354 	", TI SLLZ059 erratum = "	__stringify(QUIRK_TI_SLLZ059)
355 	", IR wake unreliable = "	__stringify(QUIRK_IR_WAKE)
356 	", phy LCtrl timeout = "	__stringify(QUIRK_PHY_LCTRL_TIMEOUT)
357 	")");
358 
359 #define OHCI_PARAM_DEBUG_AT_AR		1
360 #define OHCI_PARAM_DEBUG_SELFIDS	2
361 #define OHCI_PARAM_DEBUG_IRQS		4
362 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
363 
364 static int param_debug;
365 module_param_named(debug, param_debug, int, 0644);
366 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
367 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
368 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
369 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
370 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
371 	", or a combination, or all = -1)");
372 
373 static void log_irqs(struct fw_ohci *ohci, u32 evt)
374 {
375 	if (likely(!(param_debug &
376 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
377 		return;
378 
379 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
380 	    !(evt & OHCI1394_busReset))
381 		return;
382 
383 	ohci_notice(ohci, "IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
384 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
385 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
386 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
387 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
388 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
389 	    evt & OHCI1394_isochRx		? " IR"			: "",
390 	    evt & OHCI1394_isochTx		? " IT"			: "",
391 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
392 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
393 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
394 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
395 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
396 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
397 	    evt & OHCI1394_busReset		? " busReset"		: "",
398 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
399 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
400 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
401 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
402 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
403 		    OHCI1394_cycleInconsistent |
404 		    OHCI1394_regAccessFail | OHCI1394_busReset)
405 						? " ?"			: "");
406 }
407 
408 static const char *speed[] = {
409 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
410 };
411 static const char *power[] = {
412 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
413 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
414 };
415 static const char port[] = { '.', '-', 'p', 'c', };
416 
417 static char _p(u32 *s, int shift)
418 {
419 	return port[*s >> shift & 3];
420 }
421 
422 static void log_selfids(struct fw_ohci *ohci, int generation, int self_id_count)
423 {
424 	u32 *s;
425 
426 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
427 		return;
428 
429 	ohci_notice(ohci, "%d selfIDs, generation %d, local node ID %04x\n",
430 		    self_id_count, generation, ohci->node_id);
431 
432 	for (s = ohci->self_id_buffer; self_id_count--; ++s)
433 		if ((*s & 1 << 23) == 0)
434 			ohci_notice(ohci,
435 			    "selfID 0: %08x, phy %d [%c%c%c] %s gc=%d %s %s%s%s\n",
436 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
437 			    speed[*s >> 14 & 3], *s >> 16 & 63,
438 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
439 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
440 		else
441 			ohci_notice(ohci,
442 			    "selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
443 			    *s, *s >> 24 & 63,
444 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
445 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
446 }
447 
448 static const char *evts[] = {
449 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
450 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
451 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
452 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
453 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
454 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
455 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
456 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
457 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
458 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
459 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
460 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
461 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
462 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
463 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
464 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
465 	[0x20] = "pending/cancelled",
466 };
467 static const char *tcodes[] = {
468 	[0x0] = "QW req",		[0x1] = "BW req",
469 	[0x2] = "W resp",		[0x3] = "-reserved-",
470 	[0x4] = "QR req",		[0x5] = "BR req",
471 	[0x6] = "QR resp",		[0x7] = "BR resp",
472 	[0x8] = "cycle start",		[0x9] = "Lk req",
473 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
474 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
475 	[0xe] = "link internal",	[0xf] = "-reserved-",
476 };
477 
478 static void log_ar_at_event(struct fw_ohci *ohci,
479 			    char dir, int speed, u32 *header, int evt)
480 {
481 	int tcode = header[0] >> 4 & 0xf;
482 	char specific[12];
483 
484 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
485 		return;
486 
487 	if (unlikely(evt >= ARRAY_SIZE(evts)))
488 			evt = 0x1f;
489 
490 	if (evt == OHCI1394_evt_bus_reset) {
491 		ohci_notice(ohci, "A%c evt_bus_reset, generation %d\n",
492 			    dir, (header[2] >> 16) & 0xff);
493 		return;
494 	}
495 
496 	switch (tcode) {
497 	case 0x0: case 0x6: case 0x8:
498 		snprintf(specific, sizeof(specific), " = %08x",
499 			 be32_to_cpu((__force __be32)header[3]));
500 		break;
501 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
502 		snprintf(specific, sizeof(specific), " %x,%x",
503 			 header[3] >> 16, header[3] & 0xffff);
504 		break;
505 	default:
506 		specific[0] = '\0';
507 	}
508 
509 	switch (tcode) {
510 	case 0xa:
511 		ohci_notice(ohci, "A%c %s, %s\n",
512 			    dir, evts[evt], tcodes[tcode]);
513 		break;
514 	case 0xe:
515 		ohci_notice(ohci, "A%c %s, PHY %08x %08x\n",
516 			    dir, evts[evt], header[1], header[2]);
517 		break;
518 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
519 		ohci_notice(ohci,
520 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s, %04x%08x%s\n",
521 			    dir, speed, header[0] >> 10 & 0x3f,
522 			    header[1] >> 16, header[0] >> 16, evts[evt],
523 			    tcodes[tcode], header[1] & 0xffff, header[2], specific);
524 		break;
525 	default:
526 		ohci_notice(ohci,
527 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s%s\n",
528 			    dir, speed, header[0] >> 10 & 0x3f,
529 			    header[1] >> 16, header[0] >> 16, evts[evt],
530 			    tcodes[tcode], specific);
531 	}
532 }
533 
534 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
535 {
536 	writel(data, ohci->registers + offset);
537 }
538 
539 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
540 {
541 	return readl(ohci->registers + offset);
542 }
543 
544 static inline void flush_writes(const struct fw_ohci *ohci)
545 {
546 	/* Do a dummy read to flush writes. */
547 	reg_read(ohci, OHCI1394_Version);
548 }
549 
550 /*
551  * Beware!  read_phy_reg(), write_phy_reg(), update_phy_reg(), and
552  * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
553  * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
554  * directly.  Exceptions are intrinsically serialized contexts like pci_probe.
555  */
556 static int read_phy_reg(struct fw_ohci *ohci, int addr)
557 {
558 	u32 val;
559 	int i;
560 
561 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
562 	for (i = 0; i < 3 + 100; i++) {
563 		val = reg_read(ohci, OHCI1394_PhyControl);
564 		if (!~val)
565 			return -ENODEV; /* Card was ejected. */
566 
567 		if (val & OHCI1394_PhyControl_ReadDone)
568 			return OHCI1394_PhyControl_ReadData(val);
569 
570 		/*
571 		 * Try a few times without waiting.  Sleeping is necessary
572 		 * only when the link/PHY interface is busy.
573 		 */
574 		if (i >= 3)
575 			msleep(1);
576 	}
577 	ohci_err(ohci, "failed to read phy reg %d\n", addr);
578 	dump_stack();
579 
580 	return -EBUSY;
581 }
582 
583 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
584 {
585 	int i;
586 
587 	reg_write(ohci, OHCI1394_PhyControl,
588 		  OHCI1394_PhyControl_Write(addr, val));
589 	for (i = 0; i < 3 + 100; i++) {
590 		val = reg_read(ohci, OHCI1394_PhyControl);
591 		if (!~val)
592 			return -ENODEV; /* Card was ejected. */
593 
594 		if (!(val & OHCI1394_PhyControl_WritePending))
595 			return 0;
596 
597 		if (i >= 3)
598 			msleep(1);
599 	}
600 	ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
601 	dump_stack();
602 
603 	return -EBUSY;
604 }
605 
606 static int update_phy_reg(struct fw_ohci *ohci, int addr,
607 			  int clear_bits, int set_bits)
608 {
609 	int ret = read_phy_reg(ohci, addr);
610 	if (ret < 0)
611 		return ret;
612 
613 	/*
614 	 * The interrupt status bits are cleared by writing a one bit.
615 	 * Avoid clearing them unless explicitly requested in set_bits.
616 	 */
617 	if (addr == 5)
618 		clear_bits |= PHY_INT_STATUS_BITS;
619 
620 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
621 }
622 
623 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
624 {
625 	int ret;
626 
627 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
628 	if (ret < 0)
629 		return ret;
630 
631 	return read_phy_reg(ohci, addr);
632 }
633 
634 static int ohci_read_phy_reg(struct fw_card *card, int addr)
635 {
636 	struct fw_ohci *ohci = fw_ohci(card);
637 	int ret;
638 
639 	mutex_lock(&ohci->phy_reg_mutex);
640 	ret = read_phy_reg(ohci, addr);
641 	mutex_unlock(&ohci->phy_reg_mutex);
642 
643 	return ret;
644 }
645 
646 static int ohci_update_phy_reg(struct fw_card *card, int addr,
647 			       int clear_bits, int set_bits)
648 {
649 	struct fw_ohci *ohci = fw_ohci(card);
650 	int ret;
651 
652 	mutex_lock(&ohci->phy_reg_mutex);
653 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
654 	mutex_unlock(&ohci->phy_reg_mutex);
655 
656 	return ret;
657 }
658 
659 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
660 {
661 	return page_private(ctx->pages[i]);
662 }
663 
664 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
665 {
666 	struct descriptor *d;
667 
668 	d = &ctx->descriptors[index];
669 	d->branch_address  &= cpu_to_le32(~0xf);
670 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
671 	d->transfer_status =  0;
672 
673 	wmb(); /* finish init of new descriptors before branch_address update */
674 	d = &ctx->descriptors[ctx->last_buffer_index];
675 	d->branch_address  |= cpu_to_le32(1);
676 
677 	ctx->last_buffer_index = index;
678 
679 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
680 }
681 
682 static void ar_context_release(struct ar_context *ctx)
683 {
684 	unsigned int i;
685 
686 	if (ctx->buffer)
687 		vm_unmap_ram(ctx->buffer, AR_BUFFERS + AR_WRAPAROUND_PAGES);
688 
689 	for (i = 0; i < AR_BUFFERS; i++)
690 		if (ctx->pages[i]) {
691 			dma_unmap_page(ctx->ohci->card.device,
692 				       ar_buffer_bus(ctx, i),
693 				       PAGE_SIZE, DMA_FROM_DEVICE);
694 			__free_page(ctx->pages[i]);
695 		}
696 }
697 
698 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
699 {
700 	struct fw_ohci *ohci = ctx->ohci;
701 
702 	if (reg_read(ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
703 		reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
704 		flush_writes(ohci);
705 
706 		ohci_err(ohci, "AR error: %s; DMA stopped\n", error_msg);
707 	}
708 	/* FIXME: restart? */
709 }
710 
711 static inline unsigned int ar_next_buffer_index(unsigned int index)
712 {
713 	return (index + 1) % AR_BUFFERS;
714 }
715 
716 static inline unsigned int ar_prev_buffer_index(unsigned int index)
717 {
718 	return (index - 1 + AR_BUFFERS) % AR_BUFFERS;
719 }
720 
721 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
722 {
723 	return ar_next_buffer_index(ctx->last_buffer_index);
724 }
725 
726 /*
727  * We search for the buffer that contains the last AR packet DMA data written
728  * by the controller.
729  */
730 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
731 						 unsigned int *buffer_offset)
732 {
733 	unsigned int i, next_i, last = ctx->last_buffer_index;
734 	__le16 res_count, next_res_count;
735 
736 	i = ar_first_buffer_index(ctx);
737 	res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
738 
739 	/* A buffer that is not yet completely filled must be the last one. */
740 	while (i != last && res_count == 0) {
741 
742 		/* Peek at the next descriptor. */
743 		next_i = ar_next_buffer_index(i);
744 		rmb(); /* read descriptors in order */
745 		next_res_count = ACCESS_ONCE(
746 				ctx->descriptors[next_i].res_count);
747 		/*
748 		 * If the next descriptor is still empty, we must stop at this
749 		 * descriptor.
750 		 */
751 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
752 			/*
753 			 * The exception is when the DMA data for one packet is
754 			 * split over three buffers; in this case, the middle
755 			 * buffer's descriptor might be never updated by the
756 			 * controller and look still empty, and we have to peek
757 			 * at the third one.
758 			 */
759 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
760 				next_i = ar_next_buffer_index(next_i);
761 				rmb();
762 				next_res_count = ACCESS_ONCE(
763 					ctx->descriptors[next_i].res_count);
764 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
765 					goto next_buffer_is_active;
766 			}
767 
768 			break;
769 		}
770 
771 next_buffer_is_active:
772 		i = next_i;
773 		res_count = next_res_count;
774 	}
775 
776 	rmb(); /* read res_count before the DMA data */
777 
778 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
779 	if (*buffer_offset > PAGE_SIZE) {
780 		*buffer_offset = 0;
781 		ar_context_abort(ctx, "corrupted descriptor");
782 	}
783 
784 	return i;
785 }
786 
787 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
788 				    unsigned int end_buffer_index,
789 				    unsigned int end_buffer_offset)
790 {
791 	unsigned int i;
792 
793 	i = ar_first_buffer_index(ctx);
794 	while (i != end_buffer_index) {
795 		dma_sync_single_for_cpu(ctx->ohci->card.device,
796 					ar_buffer_bus(ctx, i),
797 					PAGE_SIZE, DMA_FROM_DEVICE);
798 		i = ar_next_buffer_index(i);
799 	}
800 	if (end_buffer_offset > 0)
801 		dma_sync_single_for_cpu(ctx->ohci->card.device,
802 					ar_buffer_bus(ctx, i),
803 					end_buffer_offset, DMA_FROM_DEVICE);
804 }
805 
806 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
807 #define cond_le32_to_cpu(v) \
808 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
809 #else
810 #define cond_le32_to_cpu(v) le32_to_cpu(v)
811 #endif
812 
813 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
814 {
815 	struct fw_ohci *ohci = ctx->ohci;
816 	struct fw_packet p;
817 	u32 status, length, tcode;
818 	int evt;
819 
820 	p.header[0] = cond_le32_to_cpu(buffer[0]);
821 	p.header[1] = cond_le32_to_cpu(buffer[1]);
822 	p.header[2] = cond_le32_to_cpu(buffer[2]);
823 
824 	tcode = (p.header[0] >> 4) & 0x0f;
825 	switch (tcode) {
826 	case TCODE_WRITE_QUADLET_REQUEST:
827 	case TCODE_READ_QUADLET_RESPONSE:
828 		p.header[3] = (__force __u32) buffer[3];
829 		p.header_length = 16;
830 		p.payload_length = 0;
831 		break;
832 
833 	case TCODE_READ_BLOCK_REQUEST :
834 		p.header[3] = cond_le32_to_cpu(buffer[3]);
835 		p.header_length = 16;
836 		p.payload_length = 0;
837 		break;
838 
839 	case TCODE_WRITE_BLOCK_REQUEST:
840 	case TCODE_READ_BLOCK_RESPONSE:
841 	case TCODE_LOCK_REQUEST:
842 	case TCODE_LOCK_RESPONSE:
843 		p.header[3] = cond_le32_to_cpu(buffer[3]);
844 		p.header_length = 16;
845 		p.payload_length = p.header[3] >> 16;
846 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
847 			ar_context_abort(ctx, "invalid packet length");
848 			return NULL;
849 		}
850 		break;
851 
852 	case TCODE_WRITE_RESPONSE:
853 	case TCODE_READ_QUADLET_REQUEST:
854 	case OHCI_TCODE_PHY_PACKET:
855 		p.header_length = 12;
856 		p.payload_length = 0;
857 		break;
858 
859 	default:
860 		ar_context_abort(ctx, "invalid tcode");
861 		return NULL;
862 	}
863 
864 	p.payload = (void *) buffer + p.header_length;
865 
866 	/* FIXME: What to do about evt_* errors? */
867 	length = (p.header_length + p.payload_length + 3) / 4;
868 	status = cond_le32_to_cpu(buffer[length]);
869 	evt    = (status >> 16) & 0x1f;
870 
871 	p.ack        = evt - 16;
872 	p.speed      = (status >> 21) & 0x7;
873 	p.timestamp  = status & 0xffff;
874 	p.generation = ohci->request_generation;
875 
876 	log_ar_at_event(ohci, 'R', p.speed, p.header, evt);
877 
878 	/*
879 	 * Several controllers, notably from NEC and VIA, forget to
880 	 * write ack_complete status at PHY packet reception.
881 	 */
882 	if (evt == OHCI1394_evt_no_status &&
883 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
884 		p.ack = ACK_COMPLETE;
885 
886 	/*
887 	 * The OHCI bus reset handler synthesizes a PHY packet with
888 	 * the new generation number when a bus reset happens (see
889 	 * section 8.4.2.3).  This helps us determine when a request
890 	 * was received and make sure we send the response in the same
891 	 * generation.  We only need this for requests; for responses
892 	 * we use the unique tlabel for finding the matching
893 	 * request.
894 	 *
895 	 * Alas some chips sometimes emit bus reset packets with a
896 	 * wrong generation.  We set the correct generation for these
897 	 * at a slightly incorrect time (in bus_reset_work).
898 	 */
899 	if (evt == OHCI1394_evt_bus_reset) {
900 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
901 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
902 	} else if (ctx == &ohci->ar_request_ctx) {
903 		fw_core_handle_request(&ohci->card, &p);
904 	} else {
905 		fw_core_handle_response(&ohci->card, &p);
906 	}
907 
908 	return buffer + length + 1;
909 }
910 
911 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
912 {
913 	void *next;
914 
915 	while (p < end) {
916 		next = handle_ar_packet(ctx, p);
917 		if (!next)
918 			return p;
919 		p = next;
920 	}
921 
922 	return p;
923 }
924 
925 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
926 {
927 	unsigned int i;
928 
929 	i = ar_first_buffer_index(ctx);
930 	while (i != end_buffer) {
931 		dma_sync_single_for_device(ctx->ohci->card.device,
932 					   ar_buffer_bus(ctx, i),
933 					   PAGE_SIZE, DMA_FROM_DEVICE);
934 		ar_context_link_page(ctx, i);
935 		i = ar_next_buffer_index(i);
936 	}
937 }
938 
939 static void ar_context_tasklet(unsigned long data)
940 {
941 	struct ar_context *ctx = (struct ar_context *)data;
942 	unsigned int end_buffer_index, end_buffer_offset;
943 	void *p, *end;
944 
945 	p = ctx->pointer;
946 	if (!p)
947 		return;
948 
949 	end_buffer_index = ar_search_last_active_buffer(ctx,
950 							&end_buffer_offset);
951 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
952 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
953 
954 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
955 		/*
956 		 * The filled part of the overall buffer wraps around; handle
957 		 * all packets up to the buffer end here.  If the last packet
958 		 * wraps around, its tail will be visible after the buffer end
959 		 * because the buffer start pages are mapped there again.
960 		 */
961 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
962 		p = handle_ar_packets(ctx, p, buffer_end);
963 		if (p < buffer_end)
964 			goto error;
965 		/* adjust p to point back into the actual buffer */
966 		p -= AR_BUFFERS * PAGE_SIZE;
967 	}
968 
969 	p = handle_ar_packets(ctx, p, end);
970 	if (p != end) {
971 		if (p > end)
972 			ar_context_abort(ctx, "inconsistent descriptor");
973 		goto error;
974 	}
975 
976 	ctx->pointer = p;
977 	ar_recycle_buffers(ctx, end_buffer_index);
978 
979 	return;
980 
981 error:
982 	ctx->pointer = NULL;
983 }
984 
985 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
986 			   unsigned int descriptors_offset, u32 regs)
987 {
988 	unsigned int i;
989 	dma_addr_t dma_addr;
990 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
991 	struct descriptor *d;
992 
993 	ctx->regs        = regs;
994 	ctx->ohci        = ohci;
995 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
996 
997 	for (i = 0; i < AR_BUFFERS; i++) {
998 		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
999 		if (!ctx->pages[i])
1000 			goto out_of_memory;
1001 		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
1002 					0, PAGE_SIZE, DMA_FROM_DEVICE);
1003 		if (dma_mapping_error(ohci->card.device, dma_addr)) {
1004 			__free_page(ctx->pages[i]);
1005 			ctx->pages[i] = NULL;
1006 			goto out_of_memory;
1007 		}
1008 		set_page_private(ctx->pages[i], dma_addr);
1009 	}
1010 
1011 	for (i = 0; i < AR_BUFFERS; i++)
1012 		pages[i]              = ctx->pages[i];
1013 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
1014 		pages[AR_BUFFERS + i] = ctx->pages[i];
1015 	ctx->buffer = vm_map_ram(pages, AR_BUFFERS + AR_WRAPAROUND_PAGES,
1016 				 -1, PAGE_KERNEL);
1017 	if (!ctx->buffer)
1018 		goto out_of_memory;
1019 
1020 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
1021 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
1022 
1023 	for (i = 0; i < AR_BUFFERS; i++) {
1024 		d = &ctx->descriptors[i];
1025 		d->req_count      = cpu_to_le16(PAGE_SIZE);
1026 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
1027 						DESCRIPTOR_STATUS |
1028 						DESCRIPTOR_BRANCH_ALWAYS);
1029 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
1030 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
1031 			ar_next_buffer_index(i) * sizeof(struct descriptor));
1032 	}
1033 
1034 	return 0;
1035 
1036 out_of_memory:
1037 	ar_context_release(ctx);
1038 
1039 	return -ENOMEM;
1040 }
1041 
1042 static void ar_context_run(struct ar_context *ctx)
1043 {
1044 	unsigned int i;
1045 
1046 	for (i = 0; i < AR_BUFFERS; i++)
1047 		ar_context_link_page(ctx, i);
1048 
1049 	ctx->pointer = ctx->buffer;
1050 
1051 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1052 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1053 }
1054 
1055 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1056 {
1057 	__le16 branch;
1058 
1059 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1060 
1061 	/* figure out which descriptor the branch address goes in */
1062 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1063 		return d;
1064 	else
1065 		return d + z - 1;
1066 }
1067 
1068 static void context_tasklet(unsigned long data)
1069 {
1070 	struct context *ctx = (struct context *) data;
1071 	struct descriptor *d, *last;
1072 	u32 address;
1073 	int z;
1074 	struct descriptor_buffer *desc;
1075 
1076 	desc = list_entry(ctx->buffer_list.next,
1077 			struct descriptor_buffer, list);
1078 	last = ctx->last;
1079 	while (last->branch_address != 0) {
1080 		struct descriptor_buffer *old_desc = desc;
1081 		address = le32_to_cpu(last->branch_address);
1082 		z = address & 0xf;
1083 		address &= ~0xf;
1084 		ctx->current_bus = address;
1085 
1086 		/* If the branch address points to a buffer outside of the
1087 		 * current buffer, advance to the next buffer. */
1088 		if (address < desc->buffer_bus ||
1089 				address >= desc->buffer_bus + desc->used)
1090 			desc = list_entry(desc->list.next,
1091 					struct descriptor_buffer, list);
1092 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1093 		last = find_branch_descriptor(d, z);
1094 
1095 		if (!ctx->callback(ctx, d, last))
1096 			break;
1097 
1098 		if (old_desc != desc) {
1099 			/* If we've advanced to the next buffer, move the
1100 			 * previous buffer to the free list. */
1101 			unsigned long flags;
1102 			old_desc->used = 0;
1103 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1104 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1105 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1106 		}
1107 		ctx->last = last;
1108 	}
1109 }
1110 
1111 /*
1112  * Allocate a new buffer and add it to the list of free buffers for this
1113  * context.  Must be called with ohci->lock held.
1114  */
1115 static int context_add_buffer(struct context *ctx)
1116 {
1117 	struct descriptor_buffer *desc;
1118 	dma_addr_t uninitialized_var(bus_addr);
1119 	int offset;
1120 
1121 	/*
1122 	 * 16MB of descriptors should be far more than enough for any DMA
1123 	 * program.  This will catch run-away userspace or DoS attacks.
1124 	 */
1125 	if (ctx->total_allocation >= 16*1024*1024)
1126 		return -ENOMEM;
1127 
1128 	desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1129 			&bus_addr, GFP_ATOMIC);
1130 	if (!desc)
1131 		return -ENOMEM;
1132 
1133 	offset = (void *)&desc->buffer - (void *)desc;
1134 	desc->buffer_size = PAGE_SIZE - offset;
1135 	desc->buffer_bus = bus_addr + offset;
1136 	desc->used = 0;
1137 
1138 	list_add_tail(&desc->list, &ctx->buffer_list);
1139 	ctx->total_allocation += PAGE_SIZE;
1140 
1141 	return 0;
1142 }
1143 
1144 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1145 			u32 regs, descriptor_callback_t callback)
1146 {
1147 	ctx->ohci = ohci;
1148 	ctx->regs = regs;
1149 	ctx->total_allocation = 0;
1150 
1151 	INIT_LIST_HEAD(&ctx->buffer_list);
1152 	if (context_add_buffer(ctx) < 0)
1153 		return -ENOMEM;
1154 
1155 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1156 			struct descriptor_buffer, list);
1157 
1158 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1159 	ctx->callback = callback;
1160 
1161 	/*
1162 	 * We put a dummy descriptor in the buffer that has a NULL
1163 	 * branch address and looks like it's been sent.  That way we
1164 	 * have a descriptor to append DMA programs to.
1165 	 */
1166 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1167 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1168 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1169 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1170 	ctx->last = ctx->buffer_tail->buffer;
1171 	ctx->prev = ctx->buffer_tail->buffer;
1172 	ctx->prev_z = 1;
1173 
1174 	return 0;
1175 }
1176 
1177 static void context_release(struct context *ctx)
1178 {
1179 	struct fw_card *card = &ctx->ohci->card;
1180 	struct descriptor_buffer *desc, *tmp;
1181 
1182 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1183 		dma_free_coherent(card->device, PAGE_SIZE, desc,
1184 			desc->buffer_bus -
1185 			((void *)&desc->buffer - (void *)desc));
1186 }
1187 
1188 /* Must be called with ohci->lock held */
1189 static struct descriptor *context_get_descriptors(struct context *ctx,
1190 						  int z, dma_addr_t *d_bus)
1191 {
1192 	struct descriptor *d = NULL;
1193 	struct descriptor_buffer *desc = ctx->buffer_tail;
1194 
1195 	if (z * sizeof(*d) > desc->buffer_size)
1196 		return NULL;
1197 
1198 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1199 		/* No room for the descriptor in this buffer, so advance to the
1200 		 * next one. */
1201 
1202 		if (desc->list.next == &ctx->buffer_list) {
1203 			/* If there is no free buffer next in the list,
1204 			 * allocate one. */
1205 			if (context_add_buffer(ctx) < 0)
1206 				return NULL;
1207 		}
1208 		desc = list_entry(desc->list.next,
1209 				struct descriptor_buffer, list);
1210 		ctx->buffer_tail = desc;
1211 	}
1212 
1213 	d = desc->buffer + desc->used / sizeof(*d);
1214 	memset(d, 0, z * sizeof(*d));
1215 	*d_bus = desc->buffer_bus + desc->used;
1216 
1217 	return d;
1218 }
1219 
1220 static void context_run(struct context *ctx, u32 extra)
1221 {
1222 	struct fw_ohci *ohci = ctx->ohci;
1223 
1224 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1225 		  le32_to_cpu(ctx->last->branch_address));
1226 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1227 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1228 	ctx->running = true;
1229 	flush_writes(ohci);
1230 }
1231 
1232 static void context_append(struct context *ctx,
1233 			   struct descriptor *d, int z, int extra)
1234 {
1235 	dma_addr_t d_bus;
1236 	struct descriptor_buffer *desc = ctx->buffer_tail;
1237 	struct descriptor *d_branch;
1238 
1239 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1240 
1241 	desc->used += (z + extra) * sizeof(*d);
1242 
1243 	wmb(); /* finish init of new descriptors before branch_address update */
1244 
1245 	d_branch = find_branch_descriptor(ctx->prev, ctx->prev_z);
1246 	d_branch->branch_address = cpu_to_le32(d_bus | z);
1247 
1248 	/*
1249 	 * VT6306 incorrectly checks only the single descriptor at the
1250 	 * CommandPtr when the wake bit is written, so if it's a
1251 	 * multi-descriptor block starting with an INPUT_MORE, put a copy of
1252 	 * the branch address in the first descriptor.
1253 	 *
1254 	 * Not doing this for transmit contexts since not sure how it interacts
1255 	 * with skip addresses.
1256 	 */
1257 	if (unlikely(ctx->ohci->quirks & QUIRK_IR_WAKE) &&
1258 	    d_branch != ctx->prev &&
1259 	    (ctx->prev->control & cpu_to_le16(DESCRIPTOR_CMD)) ==
1260 	     cpu_to_le16(DESCRIPTOR_INPUT_MORE)) {
1261 		ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1262 	}
1263 
1264 	ctx->prev = d;
1265 	ctx->prev_z = z;
1266 }
1267 
1268 static void context_stop(struct context *ctx)
1269 {
1270 	struct fw_ohci *ohci = ctx->ohci;
1271 	u32 reg;
1272 	int i;
1273 
1274 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1275 	ctx->running = false;
1276 
1277 	for (i = 0; i < 1000; i++) {
1278 		reg = reg_read(ohci, CONTROL_SET(ctx->regs));
1279 		if ((reg & CONTEXT_ACTIVE) == 0)
1280 			return;
1281 
1282 		if (i)
1283 			udelay(10);
1284 	}
1285 	ohci_err(ohci, "DMA context still active (0x%08x)\n", reg);
1286 }
1287 
1288 struct driver_data {
1289 	u8 inline_data[8];
1290 	struct fw_packet *packet;
1291 };
1292 
1293 /*
1294  * This function apppends a packet to the DMA queue for transmission.
1295  * Must always be called with the ochi->lock held to ensure proper
1296  * generation handling and locking around packet queue manipulation.
1297  */
1298 static int at_context_queue_packet(struct context *ctx,
1299 				   struct fw_packet *packet)
1300 {
1301 	struct fw_ohci *ohci = ctx->ohci;
1302 	dma_addr_t d_bus, uninitialized_var(payload_bus);
1303 	struct driver_data *driver_data;
1304 	struct descriptor *d, *last;
1305 	__le32 *header;
1306 	int z, tcode;
1307 
1308 	d = context_get_descriptors(ctx, 4, &d_bus);
1309 	if (d == NULL) {
1310 		packet->ack = RCODE_SEND_ERROR;
1311 		return -1;
1312 	}
1313 
1314 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1315 	d[0].res_count = cpu_to_le16(packet->timestamp);
1316 
1317 	/*
1318 	 * The DMA format for asynchronous link packets is different
1319 	 * from the IEEE1394 layout, so shift the fields around
1320 	 * accordingly.
1321 	 */
1322 
1323 	tcode = (packet->header[0] >> 4) & 0x0f;
1324 	header = (__le32 *) &d[1];
1325 	switch (tcode) {
1326 	case TCODE_WRITE_QUADLET_REQUEST:
1327 	case TCODE_WRITE_BLOCK_REQUEST:
1328 	case TCODE_WRITE_RESPONSE:
1329 	case TCODE_READ_QUADLET_REQUEST:
1330 	case TCODE_READ_BLOCK_REQUEST:
1331 	case TCODE_READ_QUADLET_RESPONSE:
1332 	case TCODE_READ_BLOCK_RESPONSE:
1333 	case TCODE_LOCK_REQUEST:
1334 	case TCODE_LOCK_RESPONSE:
1335 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1336 					(packet->speed << 16));
1337 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1338 					(packet->header[0] & 0xffff0000));
1339 		header[2] = cpu_to_le32(packet->header[2]);
1340 
1341 		if (TCODE_IS_BLOCK_PACKET(tcode))
1342 			header[3] = cpu_to_le32(packet->header[3]);
1343 		else
1344 			header[3] = (__force __le32) packet->header[3];
1345 
1346 		d[0].req_count = cpu_to_le16(packet->header_length);
1347 		break;
1348 
1349 	case TCODE_LINK_INTERNAL:
1350 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1351 					(packet->speed << 16));
1352 		header[1] = cpu_to_le32(packet->header[1]);
1353 		header[2] = cpu_to_le32(packet->header[2]);
1354 		d[0].req_count = cpu_to_le16(12);
1355 
1356 		if (is_ping_packet(&packet->header[1]))
1357 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1358 		break;
1359 
1360 	case TCODE_STREAM_DATA:
1361 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1362 					(packet->speed << 16));
1363 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1364 		d[0].req_count = cpu_to_le16(8);
1365 		break;
1366 
1367 	default:
1368 		/* BUG(); */
1369 		packet->ack = RCODE_SEND_ERROR;
1370 		return -1;
1371 	}
1372 
1373 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1374 	driver_data = (struct driver_data *) &d[3];
1375 	driver_data->packet = packet;
1376 	packet->driver_data = driver_data;
1377 
1378 	if (packet->payload_length > 0) {
1379 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1380 			payload_bus = dma_map_single(ohci->card.device,
1381 						     packet->payload,
1382 						     packet->payload_length,
1383 						     DMA_TO_DEVICE);
1384 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1385 				packet->ack = RCODE_SEND_ERROR;
1386 				return -1;
1387 			}
1388 			packet->payload_bus	= payload_bus;
1389 			packet->payload_mapped	= true;
1390 		} else {
1391 			memcpy(driver_data->inline_data, packet->payload,
1392 			       packet->payload_length);
1393 			payload_bus = d_bus + 3 * sizeof(*d);
1394 		}
1395 
1396 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1397 		d[2].data_address = cpu_to_le32(payload_bus);
1398 		last = &d[2];
1399 		z = 3;
1400 	} else {
1401 		last = &d[0];
1402 		z = 2;
1403 	}
1404 
1405 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1406 				     DESCRIPTOR_IRQ_ALWAYS |
1407 				     DESCRIPTOR_BRANCH_ALWAYS);
1408 
1409 	/* FIXME: Document how the locking works. */
1410 	if (ohci->generation != packet->generation) {
1411 		if (packet->payload_mapped)
1412 			dma_unmap_single(ohci->card.device, payload_bus,
1413 					 packet->payload_length, DMA_TO_DEVICE);
1414 		packet->ack = RCODE_GENERATION;
1415 		return -1;
1416 	}
1417 
1418 	context_append(ctx, d, z, 4 - z);
1419 
1420 	if (ctx->running)
1421 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1422 	else
1423 		context_run(ctx, 0);
1424 
1425 	return 0;
1426 }
1427 
1428 static void at_context_flush(struct context *ctx)
1429 {
1430 	tasklet_disable(&ctx->tasklet);
1431 
1432 	ctx->flushing = true;
1433 	context_tasklet((unsigned long)ctx);
1434 	ctx->flushing = false;
1435 
1436 	tasklet_enable(&ctx->tasklet);
1437 }
1438 
1439 static int handle_at_packet(struct context *context,
1440 			    struct descriptor *d,
1441 			    struct descriptor *last)
1442 {
1443 	struct driver_data *driver_data;
1444 	struct fw_packet *packet;
1445 	struct fw_ohci *ohci = context->ohci;
1446 	int evt;
1447 
1448 	if (last->transfer_status == 0 && !context->flushing)
1449 		/* This descriptor isn't done yet, stop iteration. */
1450 		return 0;
1451 
1452 	driver_data = (struct driver_data *) &d[3];
1453 	packet = driver_data->packet;
1454 	if (packet == NULL)
1455 		/* This packet was cancelled, just continue. */
1456 		return 1;
1457 
1458 	if (packet->payload_mapped)
1459 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1460 				 packet->payload_length, DMA_TO_DEVICE);
1461 
1462 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1463 	packet->timestamp = le16_to_cpu(last->res_count);
1464 
1465 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, evt);
1466 
1467 	switch (evt) {
1468 	case OHCI1394_evt_timeout:
1469 		/* Async response transmit timed out. */
1470 		packet->ack = RCODE_CANCELLED;
1471 		break;
1472 
1473 	case OHCI1394_evt_flushed:
1474 		/*
1475 		 * The packet was flushed should give same error as
1476 		 * when we try to use a stale generation count.
1477 		 */
1478 		packet->ack = RCODE_GENERATION;
1479 		break;
1480 
1481 	case OHCI1394_evt_missing_ack:
1482 		if (context->flushing)
1483 			packet->ack = RCODE_GENERATION;
1484 		else {
1485 			/*
1486 			 * Using a valid (current) generation count, but the
1487 			 * node is not on the bus or not sending acks.
1488 			 */
1489 			packet->ack = RCODE_NO_ACK;
1490 		}
1491 		break;
1492 
1493 	case ACK_COMPLETE + 0x10:
1494 	case ACK_PENDING + 0x10:
1495 	case ACK_BUSY_X + 0x10:
1496 	case ACK_BUSY_A + 0x10:
1497 	case ACK_BUSY_B + 0x10:
1498 	case ACK_DATA_ERROR + 0x10:
1499 	case ACK_TYPE_ERROR + 0x10:
1500 		packet->ack = evt - 0x10;
1501 		break;
1502 
1503 	case OHCI1394_evt_no_status:
1504 		if (context->flushing) {
1505 			packet->ack = RCODE_GENERATION;
1506 			break;
1507 		}
1508 		/* fall through */
1509 
1510 	default:
1511 		packet->ack = RCODE_SEND_ERROR;
1512 		break;
1513 	}
1514 
1515 	packet->callback(packet, &ohci->card, packet->ack);
1516 
1517 	return 1;
1518 }
1519 
1520 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1521 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1522 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1523 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1524 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
1525 
1526 static void handle_local_rom(struct fw_ohci *ohci,
1527 			     struct fw_packet *packet, u32 csr)
1528 {
1529 	struct fw_packet response;
1530 	int tcode, length, i;
1531 
1532 	tcode = HEADER_GET_TCODE(packet->header[0]);
1533 	if (TCODE_IS_BLOCK_PACKET(tcode))
1534 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1535 	else
1536 		length = 4;
1537 
1538 	i = csr - CSR_CONFIG_ROM;
1539 	if (i + length > CONFIG_ROM_SIZE) {
1540 		fw_fill_response(&response, packet->header,
1541 				 RCODE_ADDRESS_ERROR, NULL, 0);
1542 	} else if (!TCODE_IS_READ_REQUEST(tcode)) {
1543 		fw_fill_response(&response, packet->header,
1544 				 RCODE_TYPE_ERROR, NULL, 0);
1545 	} else {
1546 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1547 				 (void *) ohci->config_rom + i, length);
1548 	}
1549 
1550 	fw_core_handle_response(&ohci->card, &response);
1551 }
1552 
1553 static void handle_local_lock(struct fw_ohci *ohci,
1554 			      struct fw_packet *packet, u32 csr)
1555 {
1556 	struct fw_packet response;
1557 	int tcode, length, ext_tcode, sel, try;
1558 	__be32 *payload, lock_old;
1559 	u32 lock_arg, lock_data;
1560 
1561 	tcode = HEADER_GET_TCODE(packet->header[0]);
1562 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1563 	payload = packet->payload;
1564 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1565 
1566 	if (tcode == TCODE_LOCK_REQUEST &&
1567 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1568 		lock_arg = be32_to_cpu(payload[0]);
1569 		lock_data = be32_to_cpu(payload[1]);
1570 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1571 		lock_arg = 0;
1572 		lock_data = 0;
1573 	} else {
1574 		fw_fill_response(&response, packet->header,
1575 				 RCODE_TYPE_ERROR, NULL, 0);
1576 		goto out;
1577 	}
1578 
1579 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1580 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1581 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1582 	reg_write(ohci, OHCI1394_CSRControl, sel);
1583 
1584 	for (try = 0; try < 20; try++)
1585 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1586 			lock_old = cpu_to_be32(reg_read(ohci,
1587 							OHCI1394_CSRData));
1588 			fw_fill_response(&response, packet->header,
1589 					 RCODE_COMPLETE,
1590 					 &lock_old, sizeof(lock_old));
1591 			goto out;
1592 		}
1593 
1594 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
1595 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1596 
1597  out:
1598 	fw_core_handle_response(&ohci->card, &response);
1599 }
1600 
1601 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1602 {
1603 	u64 offset, csr;
1604 
1605 	if (ctx == &ctx->ohci->at_request_ctx) {
1606 		packet->ack = ACK_PENDING;
1607 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1608 	}
1609 
1610 	offset =
1611 		((unsigned long long)
1612 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1613 		packet->header[2];
1614 	csr = offset - CSR_REGISTER_BASE;
1615 
1616 	/* Handle config rom reads. */
1617 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1618 		handle_local_rom(ctx->ohci, packet, csr);
1619 	else switch (csr) {
1620 	case CSR_BUS_MANAGER_ID:
1621 	case CSR_BANDWIDTH_AVAILABLE:
1622 	case CSR_CHANNELS_AVAILABLE_HI:
1623 	case CSR_CHANNELS_AVAILABLE_LO:
1624 		handle_local_lock(ctx->ohci, packet, csr);
1625 		break;
1626 	default:
1627 		if (ctx == &ctx->ohci->at_request_ctx)
1628 			fw_core_handle_request(&ctx->ohci->card, packet);
1629 		else
1630 			fw_core_handle_response(&ctx->ohci->card, packet);
1631 		break;
1632 	}
1633 
1634 	if (ctx == &ctx->ohci->at_response_ctx) {
1635 		packet->ack = ACK_COMPLETE;
1636 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1637 	}
1638 }
1639 
1640 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1641 {
1642 	unsigned long flags;
1643 	int ret;
1644 
1645 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1646 
1647 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1648 	    ctx->ohci->generation == packet->generation) {
1649 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1650 		handle_local_request(ctx, packet);
1651 		return;
1652 	}
1653 
1654 	ret = at_context_queue_packet(ctx, packet);
1655 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1656 
1657 	if (ret < 0)
1658 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1659 
1660 }
1661 
1662 static void detect_dead_context(struct fw_ohci *ohci,
1663 				const char *name, unsigned int regs)
1664 {
1665 	u32 ctl;
1666 
1667 	ctl = reg_read(ohci, CONTROL_SET(regs));
1668 	if (ctl & CONTEXT_DEAD)
1669 		ohci_err(ohci, "DMA context %s has stopped, error code: %s\n",
1670 			name, evts[ctl & 0x1f]);
1671 }
1672 
1673 static void handle_dead_contexts(struct fw_ohci *ohci)
1674 {
1675 	unsigned int i;
1676 	char name[8];
1677 
1678 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1679 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1680 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1681 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1682 	for (i = 0; i < 32; ++i) {
1683 		if (!(ohci->it_context_support & (1 << i)))
1684 			continue;
1685 		sprintf(name, "IT%u", i);
1686 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1687 	}
1688 	for (i = 0; i < 32; ++i) {
1689 		if (!(ohci->ir_context_support & (1 << i)))
1690 			continue;
1691 		sprintf(name, "IR%u", i);
1692 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1693 	}
1694 	/* TODO: maybe try to flush and restart the dead contexts */
1695 }
1696 
1697 static u32 cycle_timer_ticks(u32 cycle_timer)
1698 {
1699 	u32 ticks;
1700 
1701 	ticks = cycle_timer & 0xfff;
1702 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1703 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1704 
1705 	return ticks;
1706 }
1707 
1708 /*
1709  * Some controllers exhibit one or more of the following bugs when updating the
1710  * iso cycle timer register:
1711  *  - When the lowest six bits are wrapping around to zero, a read that happens
1712  *    at the same time will return garbage in the lowest ten bits.
1713  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1714  *    not incremented for about 60 ns.
1715  *  - Occasionally, the entire register reads zero.
1716  *
1717  * To catch these, we read the register three times and ensure that the
1718  * difference between each two consecutive reads is approximately the same, i.e.
1719  * less than twice the other.  Furthermore, any negative difference indicates an
1720  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1721  * execute, so we have enough precision to compute the ratio of the differences.)
1722  */
1723 static u32 get_cycle_time(struct fw_ohci *ohci)
1724 {
1725 	u32 c0, c1, c2;
1726 	u32 t0, t1, t2;
1727 	s32 diff01, diff12;
1728 	int i;
1729 
1730 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1731 
1732 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1733 		i = 0;
1734 		c1 = c2;
1735 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1736 		do {
1737 			c0 = c1;
1738 			c1 = c2;
1739 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1740 			t0 = cycle_timer_ticks(c0);
1741 			t1 = cycle_timer_ticks(c1);
1742 			t2 = cycle_timer_ticks(c2);
1743 			diff01 = t1 - t0;
1744 			diff12 = t2 - t1;
1745 		} while ((diff01 <= 0 || diff12 <= 0 ||
1746 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1747 			 && i++ < 20);
1748 	}
1749 
1750 	return c2;
1751 }
1752 
1753 /*
1754  * This function has to be called at least every 64 seconds.  The bus_time
1755  * field stores not only the upper 25 bits of the BUS_TIME register but also
1756  * the most significant bit of the cycle timer in bit 6 so that we can detect
1757  * changes in this bit.
1758  */
1759 static u32 update_bus_time(struct fw_ohci *ohci)
1760 {
1761 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1762 
1763 	if (unlikely(!ohci->bus_time_running)) {
1764 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds);
1765 		ohci->bus_time = (lower_32_bits(get_seconds()) & ~0x7f) |
1766 		                 (cycle_time_seconds & 0x40);
1767 		ohci->bus_time_running = true;
1768 	}
1769 
1770 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1771 		ohci->bus_time += 0x40;
1772 
1773 	return ohci->bus_time | cycle_time_seconds;
1774 }
1775 
1776 static int get_status_for_port(struct fw_ohci *ohci, int port_index)
1777 {
1778 	int reg;
1779 
1780 	mutex_lock(&ohci->phy_reg_mutex);
1781 	reg = write_phy_reg(ohci, 7, port_index);
1782 	if (reg >= 0)
1783 		reg = read_phy_reg(ohci, 8);
1784 	mutex_unlock(&ohci->phy_reg_mutex);
1785 	if (reg < 0)
1786 		return reg;
1787 
1788 	switch (reg & 0x0f) {
1789 	case 0x06:
1790 		return 2;	/* is child node (connected to parent node) */
1791 	case 0x0e:
1792 		return 3;	/* is parent node (connected to child node) */
1793 	}
1794 	return 1;		/* not connected */
1795 }
1796 
1797 static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
1798 	int self_id_count)
1799 {
1800 	int i;
1801 	u32 entry;
1802 
1803 	for (i = 0; i < self_id_count; i++) {
1804 		entry = ohci->self_id_buffer[i];
1805 		if ((self_id & 0xff000000) == (entry & 0xff000000))
1806 			return -1;
1807 		if ((self_id & 0xff000000) < (entry & 0xff000000))
1808 			return i;
1809 	}
1810 	return i;
1811 }
1812 
1813 static int initiated_reset(struct fw_ohci *ohci)
1814 {
1815 	int reg;
1816 	int ret = 0;
1817 
1818 	mutex_lock(&ohci->phy_reg_mutex);
1819 	reg = write_phy_reg(ohci, 7, 0xe0); /* Select page 7 */
1820 	if (reg >= 0) {
1821 		reg = read_phy_reg(ohci, 8);
1822 		reg |= 0x40;
1823 		reg = write_phy_reg(ohci, 8, reg); /* set PMODE bit */
1824 		if (reg >= 0) {
1825 			reg = read_phy_reg(ohci, 12); /* read register 12 */
1826 			if (reg >= 0) {
1827 				if ((reg & 0x08) == 0x08) {
1828 					/* bit 3 indicates "initiated reset" */
1829 					ret = 0x2;
1830 				}
1831 			}
1832 		}
1833 	}
1834 	mutex_unlock(&ohci->phy_reg_mutex);
1835 	return ret;
1836 }
1837 
1838 /*
1839  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
1840  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
1841  * Construct the selfID from phy register contents.
1842  */
1843 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
1844 {
1845 	int reg, i, pos, status;
1846 	/* link active 1, speed 3, bridge 0, contender 1, more packets 0 */
1847 	u32 self_id = 0x8040c800;
1848 
1849 	reg = reg_read(ohci, OHCI1394_NodeID);
1850 	if (!(reg & OHCI1394_NodeID_idValid)) {
1851 		ohci_notice(ohci,
1852 			    "node ID not valid, new bus reset in progress\n");
1853 		return -EBUSY;
1854 	}
1855 	self_id |= ((reg & 0x3f) << 24); /* phy ID */
1856 
1857 	reg = ohci_read_phy_reg(&ohci->card, 4);
1858 	if (reg < 0)
1859 		return reg;
1860 	self_id |= ((reg & 0x07) << 8); /* power class */
1861 
1862 	reg = ohci_read_phy_reg(&ohci->card, 1);
1863 	if (reg < 0)
1864 		return reg;
1865 	self_id |= ((reg & 0x3f) << 16); /* gap count */
1866 
1867 	for (i = 0; i < 3; i++) {
1868 		status = get_status_for_port(ohci, i);
1869 		if (status < 0)
1870 			return status;
1871 		self_id |= ((status & 0x3) << (6 - (i * 2)));
1872 	}
1873 
1874 	self_id |= initiated_reset(ohci);
1875 
1876 	pos = get_self_id_pos(ohci, self_id, self_id_count);
1877 	if (pos >= 0) {
1878 		memmove(&(ohci->self_id_buffer[pos+1]),
1879 			&(ohci->self_id_buffer[pos]),
1880 			(self_id_count - pos) * sizeof(*ohci->self_id_buffer));
1881 		ohci->self_id_buffer[pos] = self_id;
1882 		self_id_count++;
1883 	}
1884 	return self_id_count;
1885 }
1886 
1887 static void bus_reset_work(struct work_struct *work)
1888 {
1889 	struct fw_ohci *ohci =
1890 		container_of(work, struct fw_ohci, bus_reset_work);
1891 	int self_id_count, generation, new_generation, i, j;
1892 	u32 reg;
1893 	void *free_rom = NULL;
1894 	dma_addr_t free_rom_bus = 0;
1895 	bool is_new_root;
1896 
1897 	reg = reg_read(ohci, OHCI1394_NodeID);
1898 	if (!(reg & OHCI1394_NodeID_idValid)) {
1899 		ohci_notice(ohci,
1900 			    "node ID not valid, new bus reset in progress\n");
1901 		return;
1902 	}
1903 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1904 		ohci_notice(ohci, "malconfigured bus\n");
1905 		return;
1906 	}
1907 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1908 			       OHCI1394_NodeID_nodeNumber);
1909 
1910 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1911 	if (!(ohci->is_root && is_new_root))
1912 		reg_write(ohci, OHCI1394_LinkControlSet,
1913 			  OHCI1394_LinkControl_cycleMaster);
1914 	ohci->is_root = is_new_root;
1915 
1916 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1917 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1918 		ohci_notice(ohci, "self ID receive error\n");
1919 		return;
1920 	}
1921 	/*
1922 	 * The count in the SelfIDCount register is the number of
1923 	 * bytes in the self ID receive buffer.  Since we also receive
1924 	 * the inverted quadlets and a header quadlet, we shift one
1925 	 * bit extra to get the actual number of self IDs.
1926 	 */
1927 	self_id_count = (reg >> 3) & 0xff;
1928 
1929 	if (self_id_count > 252) {
1930 		ohci_notice(ohci, "bad selfIDSize (%08x)\n", reg);
1931 		return;
1932 	}
1933 
1934 	generation = (cond_le32_to_cpu(ohci->self_id[0]) >> 16) & 0xff;
1935 	rmb();
1936 
1937 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1938 		u32 id  = cond_le32_to_cpu(ohci->self_id[i]);
1939 		u32 id2 = cond_le32_to_cpu(ohci->self_id[i + 1]);
1940 
1941 		if (id != ~id2) {
1942 			/*
1943 			 * If the invalid data looks like a cycle start packet,
1944 			 * it's likely to be the result of the cycle master
1945 			 * having a wrong gap count.  In this case, the self IDs
1946 			 * so far are valid and should be processed so that the
1947 			 * bus manager can then correct the gap count.
1948 			 */
1949 			if (id == 0xffff008f) {
1950 				ohci_notice(ohci, "ignoring spurious self IDs\n");
1951 				self_id_count = j;
1952 				break;
1953 			}
1954 
1955 			ohci_notice(ohci, "bad self ID %d/%d (%08x != ~%08x)\n",
1956 				    j, self_id_count, id, id2);
1957 			return;
1958 		}
1959 		ohci->self_id_buffer[j] = id;
1960 	}
1961 
1962 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
1963 		self_id_count = find_and_insert_self_id(ohci, self_id_count);
1964 		if (self_id_count < 0) {
1965 			ohci_notice(ohci,
1966 				    "could not construct local self ID\n");
1967 			return;
1968 		}
1969 	}
1970 
1971 	if (self_id_count == 0) {
1972 		ohci_notice(ohci, "no self IDs\n");
1973 		return;
1974 	}
1975 	rmb();
1976 
1977 	/*
1978 	 * Check the consistency of the self IDs we just read.  The
1979 	 * problem we face is that a new bus reset can start while we
1980 	 * read out the self IDs from the DMA buffer. If this happens,
1981 	 * the DMA buffer will be overwritten with new self IDs and we
1982 	 * will read out inconsistent data.  The OHCI specification
1983 	 * (section 11.2) recommends a technique similar to
1984 	 * linux/seqlock.h, where we remember the generation of the
1985 	 * self IDs in the buffer before reading them out and compare
1986 	 * it to the current generation after reading them out.  If
1987 	 * the two generations match we know we have a consistent set
1988 	 * of self IDs.
1989 	 */
1990 
1991 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1992 	if (new_generation != generation) {
1993 		ohci_notice(ohci, "new bus reset, discarding self ids\n");
1994 		return;
1995 	}
1996 
1997 	/* FIXME: Document how the locking works. */
1998 	spin_lock_irq(&ohci->lock);
1999 
2000 	ohci->generation = -1; /* prevent AT packet queueing */
2001 	context_stop(&ohci->at_request_ctx);
2002 	context_stop(&ohci->at_response_ctx);
2003 
2004 	spin_unlock_irq(&ohci->lock);
2005 
2006 	/*
2007 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
2008 	 * packets in the AT queues and software needs to drain them.
2009 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
2010 	 */
2011 	at_context_flush(&ohci->at_request_ctx);
2012 	at_context_flush(&ohci->at_response_ctx);
2013 
2014 	spin_lock_irq(&ohci->lock);
2015 
2016 	ohci->generation = generation;
2017 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
2018 
2019 	if (ohci->quirks & QUIRK_RESET_PACKET)
2020 		ohci->request_generation = generation;
2021 
2022 	/*
2023 	 * This next bit is unrelated to the AT context stuff but we
2024 	 * have to do it under the spinlock also.  If a new config rom
2025 	 * was set up before this reset, the old one is now no longer
2026 	 * in use and we can free it. Update the config rom pointers
2027 	 * to point to the current config rom and clear the
2028 	 * next_config_rom pointer so a new update can take place.
2029 	 */
2030 
2031 	if (ohci->next_config_rom != NULL) {
2032 		if (ohci->next_config_rom != ohci->config_rom) {
2033 			free_rom      = ohci->config_rom;
2034 			free_rom_bus  = ohci->config_rom_bus;
2035 		}
2036 		ohci->config_rom      = ohci->next_config_rom;
2037 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
2038 		ohci->next_config_rom = NULL;
2039 
2040 		/*
2041 		 * Restore config_rom image and manually update
2042 		 * config_rom registers.  Writing the header quadlet
2043 		 * will indicate that the config rom is ready, so we
2044 		 * do that last.
2045 		 */
2046 		reg_write(ohci, OHCI1394_BusOptions,
2047 			  be32_to_cpu(ohci->config_rom[2]));
2048 		ohci->config_rom[0] = ohci->next_header;
2049 		reg_write(ohci, OHCI1394_ConfigROMhdr,
2050 			  be32_to_cpu(ohci->next_header));
2051 	}
2052 
2053 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
2054 	reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
2055 	reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
2056 #endif
2057 
2058 	spin_unlock_irq(&ohci->lock);
2059 
2060 	if (free_rom)
2061 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2062 				  free_rom, free_rom_bus);
2063 
2064 	log_selfids(ohci, generation, self_id_count);
2065 
2066 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
2067 				 self_id_count, ohci->self_id_buffer,
2068 				 ohci->csr_state_setclear_abdicate);
2069 	ohci->csr_state_setclear_abdicate = false;
2070 }
2071 
2072 static irqreturn_t irq_handler(int irq, void *data)
2073 {
2074 	struct fw_ohci *ohci = data;
2075 	u32 event, iso_event;
2076 	int i;
2077 
2078 	event = reg_read(ohci, OHCI1394_IntEventClear);
2079 
2080 	if (!event || !~event)
2081 		return IRQ_NONE;
2082 
2083 	/*
2084 	 * busReset and postedWriteErr must not be cleared yet
2085 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
2086 	 */
2087 	reg_write(ohci, OHCI1394_IntEventClear,
2088 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
2089 	log_irqs(ohci, event);
2090 
2091 	if (event & OHCI1394_selfIDComplete)
2092 		queue_work(selfid_workqueue, &ohci->bus_reset_work);
2093 
2094 	if (event & OHCI1394_RQPkt)
2095 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
2096 
2097 	if (event & OHCI1394_RSPkt)
2098 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
2099 
2100 	if (event & OHCI1394_reqTxComplete)
2101 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
2102 
2103 	if (event & OHCI1394_respTxComplete)
2104 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
2105 
2106 	if (event & OHCI1394_isochRx) {
2107 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
2108 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
2109 
2110 		while (iso_event) {
2111 			i = ffs(iso_event) - 1;
2112 			tasklet_schedule(
2113 				&ohci->ir_context_list[i].context.tasklet);
2114 			iso_event &= ~(1 << i);
2115 		}
2116 	}
2117 
2118 	if (event & OHCI1394_isochTx) {
2119 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
2120 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
2121 
2122 		while (iso_event) {
2123 			i = ffs(iso_event) - 1;
2124 			tasklet_schedule(
2125 				&ohci->it_context_list[i].context.tasklet);
2126 			iso_event &= ~(1 << i);
2127 		}
2128 	}
2129 
2130 	if (unlikely(event & OHCI1394_regAccessFail))
2131 		ohci_err(ohci, "register access failure\n");
2132 
2133 	if (unlikely(event & OHCI1394_postedWriteErr)) {
2134 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
2135 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
2136 		reg_write(ohci, OHCI1394_IntEventClear,
2137 			  OHCI1394_postedWriteErr);
2138 		if (printk_ratelimit())
2139 			ohci_err(ohci, "PCI posted write error\n");
2140 	}
2141 
2142 	if (unlikely(event & OHCI1394_cycleTooLong)) {
2143 		if (printk_ratelimit())
2144 			ohci_notice(ohci, "isochronous cycle too long\n");
2145 		reg_write(ohci, OHCI1394_LinkControlSet,
2146 			  OHCI1394_LinkControl_cycleMaster);
2147 	}
2148 
2149 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
2150 		/*
2151 		 * We need to clear this event bit in order to make
2152 		 * cycleMatch isochronous I/O work.  In theory we should
2153 		 * stop active cycleMatch iso contexts now and restart
2154 		 * them at least two cycles later.  (FIXME?)
2155 		 */
2156 		if (printk_ratelimit())
2157 			ohci_notice(ohci, "isochronous cycle inconsistent\n");
2158 	}
2159 
2160 	if (unlikely(event & OHCI1394_unrecoverableError))
2161 		handle_dead_contexts(ohci);
2162 
2163 	if (event & OHCI1394_cycle64Seconds) {
2164 		spin_lock(&ohci->lock);
2165 		update_bus_time(ohci);
2166 		spin_unlock(&ohci->lock);
2167 	} else
2168 		flush_writes(ohci);
2169 
2170 	return IRQ_HANDLED;
2171 }
2172 
2173 static int software_reset(struct fw_ohci *ohci)
2174 {
2175 	u32 val;
2176 	int i;
2177 
2178 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
2179 	for (i = 0; i < 500; i++) {
2180 		val = reg_read(ohci, OHCI1394_HCControlSet);
2181 		if (!~val)
2182 			return -ENODEV; /* Card was ejected. */
2183 
2184 		if (!(val & OHCI1394_HCControl_softReset))
2185 			return 0;
2186 
2187 		msleep(1);
2188 	}
2189 
2190 	return -EBUSY;
2191 }
2192 
2193 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
2194 {
2195 	size_t size = length * 4;
2196 
2197 	memcpy(dest, src, size);
2198 	if (size < CONFIG_ROM_SIZE)
2199 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
2200 }
2201 
2202 static int configure_1394a_enhancements(struct fw_ohci *ohci)
2203 {
2204 	bool enable_1394a;
2205 	int ret, clear, set, offset;
2206 
2207 	/* Check if the driver should configure link and PHY. */
2208 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
2209 	      OHCI1394_HCControl_programPhyEnable))
2210 		return 0;
2211 
2212 	/* Paranoia: check whether the PHY supports 1394a, too. */
2213 	enable_1394a = false;
2214 	ret = read_phy_reg(ohci, 2);
2215 	if (ret < 0)
2216 		return ret;
2217 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2218 		ret = read_paged_phy_reg(ohci, 1, 8);
2219 		if (ret < 0)
2220 			return ret;
2221 		if (ret >= 1)
2222 			enable_1394a = true;
2223 	}
2224 
2225 	if (ohci->quirks & QUIRK_NO_1394A)
2226 		enable_1394a = false;
2227 
2228 	/* Configure PHY and link consistently. */
2229 	if (enable_1394a) {
2230 		clear = 0;
2231 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2232 	} else {
2233 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2234 		set = 0;
2235 	}
2236 	ret = update_phy_reg(ohci, 5, clear, set);
2237 	if (ret < 0)
2238 		return ret;
2239 
2240 	if (enable_1394a)
2241 		offset = OHCI1394_HCControlSet;
2242 	else
2243 		offset = OHCI1394_HCControlClear;
2244 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2245 
2246 	/* Clean up: configuration has been taken care of. */
2247 	reg_write(ohci, OHCI1394_HCControlClear,
2248 		  OHCI1394_HCControl_programPhyEnable);
2249 
2250 	return 0;
2251 }
2252 
2253 static int probe_tsb41ba3d(struct fw_ohci *ohci)
2254 {
2255 	/* TI vendor ID = 0x080028, TSB41BA3D product ID = 0x833005 (sic) */
2256 	static const u8 id[] = { 0x08, 0x00, 0x28, 0x83, 0x30, 0x05, };
2257 	int reg, i;
2258 
2259 	reg = read_phy_reg(ohci, 2);
2260 	if (reg < 0)
2261 		return reg;
2262 	if ((reg & PHY_EXTENDED_REGISTERS) != PHY_EXTENDED_REGISTERS)
2263 		return 0;
2264 
2265 	for (i = ARRAY_SIZE(id) - 1; i >= 0; i--) {
2266 		reg = read_paged_phy_reg(ohci, 1, i + 10);
2267 		if (reg < 0)
2268 			return reg;
2269 		if (reg != id[i])
2270 			return 0;
2271 	}
2272 	return 1;
2273 }
2274 
2275 static int ohci_enable(struct fw_card *card,
2276 		       const __be32 *config_rom, size_t length)
2277 {
2278 	struct fw_ohci *ohci = fw_ohci(card);
2279 	u32 lps, version, irqs;
2280 	int i, ret;
2281 
2282 	if (software_reset(ohci)) {
2283 		ohci_err(ohci, "failed to reset ohci card\n");
2284 		return -EBUSY;
2285 	}
2286 
2287 	/*
2288 	 * Now enable LPS, which we need in order to start accessing
2289 	 * most of the registers.  In fact, on some cards (ALI M5251),
2290 	 * accessing registers in the SClk domain without LPS enabled
2291 	 * will lock up the machine.  Wait 50msec to make sure we have
2292 	 * full link enabled.  However, with some cards (well, at least
2293 	 * a JMicron PCIe card), we have to try again sometimes.
2294 	 *
2295 	 * TI TSB82AA2 + TSB81BA3(A) cards signal LPS enabled early but
2296 	 * cannot actually use the phy at that time.  These need tens of
2297 	 * millisecods pause between LPS write and first phy access too.
2298 	 *
2299 	 * But do not wait for 50msec on Agere/LSI cards.  Their phy
2300 	 * arbitration state machine may time out during such a long wait.
2301 	 */
2302 
2303 	reg_write(ohci, OHCI1394_HCControlSet,
2304 		  OHCI1394_HCControl_LPS |
2305 		  OHCI1394_HCControl_postedWriteEnable);
2306 	flush_writes(ohci);
2307 
2308 	if (!(ohci->quirks & QUIRK_PHY_LCTRL_TIMEOUT))
2309 		msleep(50);
2310 
2311 	for (lps = 0, i = 0; !lps && i < 150; i++) {
2312 		msleep(1);
2313 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2314 		      OHCI1394_HCControl_LPS;
2315 	}
2316 
2317 	if (!lps) {
2318 		ohci_err(ohci, "failed to set Link Power Status\n");
2319 		return -EIO;
2320 	}
2321 
2322 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2323 		ret = probe_tsb41ba3d(ohci);
2324 		if (ret < 0)
2325 			return ret;
2326 		if (ret)
2327 			ohci_notice(ohci, "local TSB41BA3D phy\n");
2328 		else
2329 			ohci->quirks &= ~QUIRK_TI_SLLZ059;
2330 	}
2331 
2332 	reg_write(ohci, OHCI1394_HCControlClear,
2333 		  OHCI1394_HCControl_noByteSwapData);
2334 
2335 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2336 	reg_write(ohci, OHCI1394_LinkControlSet,
2337 		  OHCI1394_LinkControl_cycleTimerEnable |
2338 		  OHCI1394_LinkControl_cycleMaster);
2339 
2340 	reg_write(ohci, OHCI1394_ATRetries,
2341 		  OHCI1394_MAX_AT_REQ_RETRIES |
2342 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2343 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2344 		  (200 << 16));
2345 
2346 	ohci->bus_time_running = false;
2347 
2348 	for (i = 0; i < 32; i++)
2349 		if (ohci->ir_context_support & (1 << i))
2350 			reg_write(ohci, OHCI1394_IsoRcvContextControlClear(i),
2351 				  IR_CONTEXT_MULTI_CHANNEL_MODE);
2352 
2353 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2354 	if (version >= OHCI_VERSION_1_1) {
2355 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2356 			  0xfffffffe);
2357 		card->broadcast_channel_auto_allocated = true;
2358 	}
2359 
2360 	/* Get implemented bits of the priority arbitration request counter. */
2361 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2362 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2363 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2364 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2365 
2366 	reg_write(ohci, OHCI1394_PhyUpperBound, 0x00010000);
2367 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2368 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2369 
2370 	ret = configure_1394a_enhancements(ohci);
2371 	if (ret < 0)
2372 		return ret;
2373 
2374 	/* Activate link_on bit and contender bit in our self ID packets.*/
2375 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2376 	if (ret < 0)
2377 		return ret;
2378 
2379 	/*
2380 	 * When the link is not yet enabled, the atomic config rom
2381 	 * update mechanism described below in ohci_set_config_rom()
2382 	 * is not active.  We have to update ConfigRomHeader and
2383 	 * BusOptions manually, and the write to ConfigROMmap takes
2384 	 * effect immediately.  We tie this to the enabling of the
2385 	 * link, so we have a valid config rom before enabling - the
2386 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2387 	 * values before enabling.
2388 	 *
2389 	 * However, when the ConfigROMmap is written, some controllers
2390 	 * always read back quadlets 0 and 2 from the config rom to
2391 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2392 	 * They shouldn't do that in this initial case where the link
2393 	 * isn't enabled.  This means we have to use the same
2394 	 * workaround here, setting the bus header to 0 and then write
2395 	 * the right values in the bus reset tasklet.
2396 	 */
2397 
2398 	if (config_rom) {
2399 		ohci->next_config_rom =
2400 			dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2401 					   &ohci->next_config_rom_bus,
2402 					   GFP_KERNEL);
2403 		if (ohci->next_config_rom == NULL)
2404 			return -ENOMEM;
2405 
2406 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2407 	} else {
2408 		/*
2409 		 * In the suspend case, config_rom is NULL, which
2410 		 * means that we just reuse the old config rom.
2411 		 */
2412 		ohci->next_config_rom = ohci->config_rom;
2413 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2414 	}
2415 
2416 	ohci->next_header = ohci->next_config_rom[0];
2417 	ohci->next_config_rom[0] = 0;
2418 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2419 	reg_write(ohci, OHCI1394_BusOptions,
2420 		  be32_to_cpu(ohci->next_config_rom[2]));
2421 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2422 
2423 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2424 
2425 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2426 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2427 		OHCI1394_isochTx | OHCI1394_isochRx |
2428 		OHCI1394_postedWriteErr |
2429 		OHCI1394_selfIDComplete |
2430 		OHCI1394_regAccessFail |
2431 		OHCI1394_cycleInconsistent |
2432 		OHCI1394_unrecoverableError |
2433 		OHCI1394_cycleTooLong |
2434 		OHCI1394_masterIntEnable;
2435 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2436 		irqs |= OHCI1394_busReset;
2437 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2438 
2439 	reg_write(ohci, OHCI1394_HCControlSet,
2440 		  OHCI1394_HCControl_linkEnable |
2441 		  OHCI1394_HCControl_BIBimageValid);
2442 
2443 	reg_write(ohci, OHCI1394_LinkControlSet,
2444 		  OHCI1394_LinkControl_rcvSelfID |
2445 		  OHCI1394_LinkControl_rcvPhyPkt);
2446 
2447 	ar_context_run(&ohci->ar_request_ctx);
2448 	ar_context_run(&ohci->ar_response_ctx);
2449 
2450 	flush_writes(ohci);
2451 
2452 	/* We are ready to go, reset bus to finish initialization. */
2453 	fw_schedule_bus_reset(&ohci->card, false, true);
2454 
2455 	return 0;
2456 }
2457 
2458 static int ohci_set_config_rom(struct fw_card *card,
2459 			       const __be32 *config_rom, size_t length)
2460 {
2461 	struct fw_ohci *ohci;
2462 	__be32 *next_config_rom;
2463 	dma_addr_t uninitialized_var(next_config_rom_bus);
2464 
2465 	ohci = fw_ohci(card);
2466 
2467 	/*
2468 	 * When the OHCI controller is enabled, the config rom update
2469 	 * mechanism is a bit tricky, but easy enough to use.  See
2470 	 * section 5.5.6 in the OHCI specification.
2471 	 *
2472 	 * The OHCI controller caches the new config rom address in a
2473 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2474 	 * for the changes to take place.  When the bus reset is
2475 	 * detected, the controller loads the new values for the
2476 	 * ConfigRomHeader and BusOptions registers from the specified
2477 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2478 	 * shadow register. All automatically and atomically.
2479 	 *
2480 	 * Now, there's a twist to this story.  The automatic load of
2481 	 * ConfigRomHeader and BusOptions doesn't honor the
2482 	 * noByteSwapData bit, so with a be32 config rom, the
2483 	 * controller will load be32 values in to these registers
2484 	 * during the atomic update, even on litte endian
2485 	 * architectures.  The workaround we use is to put a 0 in the
2486 	 * header quadlet; 0 is endian agnostic and means that the
2487 	 * config rom isn't ready yet.  In the bus reset tasklet we
2488 	 * then set up the real values for the two registers.
2489 	 *
2490 	 * We use ohci->lock to avoid racing with the code that sets
2491 	 * ohci->next_config_rom to NULL (see bus_reset_work).
2492 	 */
2493 
2494 	next_config_rom =
2495 		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2496 				   &next_config_rom_bus, GFP_KERNEL);
2497 	if (next_config_rom == NULL)
2498 		return -ENOMEM;
2499 
2500 	spin_lock_irq(&ohci->lock);
2501 
2502 	/*
2503 	 * If there is not an already pending config_rom update,
2504 	 * push our new allocation into the ohci->next_config_rom
2505 	 * and then mark the local variable as null so that we
2506 	 * won't deallocate the new buffer.
2507 	 *
2508 	 * OTOH, if there is a pending config_rom update, just
2509 	 * use that buffer with the new config_rom data, and
2510 	 * let this routine free the unused DMA allocation.
2511 	 */
2512 
2513 	if (ohci->next_config_rom == NULL) {
2514 		ohci->next_config_rom = next_config_rom;
2515 		ohci->next_config_rom_bus = next_config_rom_bus;
2516 		next_config_rom = NULL;
2517 	}
2518 
2519 	copy_config_rom(ohci->next_config_rom, config_rom, length);
2520 
2521 	ohci->next_header = config_rom[0];
2522 	ohci->next_config_rom[0] = 0;
2523 
2524 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2525 
2526 	spin_unlock_irq(&ohci->lock);
2527 
2528 	/* If we didn't use the DMA allocation, delete it. */
2529 	if (next_config_rom != NULL)
2530 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2531 				  next_config_rom, next_config_rom_bus);
2532 
2533 	/*
2534 	 * Now initiate a bus reset to have the changes take
2535 	 * effect. We clean up the old config rom memory and DMA
2536 	 * mappings in the bus reset tasklet, since the OHCI
2537 	 * controller could need to access it before the bus reset
2538 	 * takes effect.
2539 	 */
2540 
2541 	fw_schedule_bus_reset(&ohci->card, true, true);
2542 
2543 	return 0;
2544 }
2545 
2546 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2547 {
2548 	struct fw_ohci *ohci = fw_ohci(card);
2549 
2550 	at_context_transmit(&ohci->at_request_ctx, packet);
2551 }
2552 
2553 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2554 {
2555 	struct fw_ohci *ohci = fw_ohci(card);
2556 
2557 	at_context_transmit(&ohci->at_response_ctx, packet);
2558 }
2559 
2560 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2561 {
2562 	struct fw_ohci *ohci = fw_ohci(card);
2563 	struct context *ctx = &ohci->at_request_ctx;
2564 	struct driver_data *driver_data = packet->driver_data;
2565 	int ret = -ENOENT;
2566 
2567 	tasklet_disable(&ctx->tasklet);
2568 
2569 	if (packet->ack != 0)
2570 		goto out;
2571 
2572 	if (packet->payload_mapped)
2573 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2574 				 packet->payload_length, DMA_TO_DEVICE);
2575 
2576 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, 0x20);
2577 	driver_data->packet = NULL;
2578 	packet->ack = RCODE_CANCELLED;
2579 	packet->callback(packet, &ohci->card, packet->ack);
2580 	ret = 0;
2581  out:
2582 	tasklet_enable(&ctx->tasklet);
2583 
2584 	return ret;
2585 }
2586 
2587 static int ohci_enable_phys_dma(struct fw_card *card,
2588 				int node_id, int generation)
2589 {
2590 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
2591 	return 0;
2592 #else
2593 	struct fw_ohci *ohci = fw_ohci(card);
2594 	unsigned long flags;
2595 	int n, ret = 0;
2596 
2597 	/*
2598 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2599 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2600 	 */
2601 
2602 	spin_lock_irqsave(&ohci->lock, flags);
2603 
2604 	if (ohci->generation != generation) {
2605 		ret = -ESTALE;
2606 		goto out;
2607 	}
2608 
2609 	/*
2610 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2611 	 * enabled for _all_ nodes on remote buses.
2612 	 */
2613 
2614 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2615 	if (n < 32)
2616 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2617 	else
2618 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2619 
2620 	flush_writes(ohci);
2621  out:
2622 	spin_unlock_irqrestore(&ohci->lock, flags);
2623 
2624 	return ret;
2625 #endif /* CONFIG_FIREWIRE_OHCI_REMOTE_DMA */
2626 }
2627 
2628 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2629 {
2630 	struct fw_ohci *ohci = fw_ohci(card);
2631 	unsigned long flags;
2632 	u32 value;
2633 
2634 	switch (csr_offset) {
2635 	case CSR_STATE_CLEAR:
2636 	case CSR_STATE_SET:
2637 		if (ohci->is_root &&
2638 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2639 		     OHCI1394_LinkControl_cycleMaster))
2640 			value = CSR_STATE_BIT_CMSTR;
2641 		else
2642 			value = 0;
2643 		if (ohci->csr_state_setclear_abdicate)
2644 			value |= CSR_STATE_BIT_ABDICATE;
2645 
2646 		return value;
2647 
2648 	case CSR_NODE_IDS:
2649 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2650 
2651 	case CSR_CYCLE_TIME:
2652 		return get_cycle_time(ohci);
2653 
2654 	case CSR_BUS_TIME:
2655 		/*
2656 		 * We might be called just after the cycle timer has wrapped
2657 		 * around but just before the cycle64Seconds handler, so we
2658 		 * better check here, too, if the bus time needs to be updated.
2659 		 */
2660 		spin_lock_irqsave(&ohci->lock, flags);
2661 		value = update_bus_time(ohci);
2662 		spin_unlock_irqrestore(&ohci->lock, flags);
2663 		return value;
2664 
2665 	case CSR_BUSY_TIMEOUT:
2666 		value = reg_read(ohci, OHCI1394_ATRetries);
2667 		return (value >> 4) & 0x0ffff00f;
2668 
2669 	case CSR_PRIORITY_BUDGET:
2670 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2671 			(ohci->pri_req_max << 8);
2672 
2673 	default:
2674 		WARN_ON(1);
2675 		return 0;
2676 	}
2677 }
2678 
2679 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2680 {
2681 	struct fw_ohci *ohci = fw_ohci(card);
2682 	unsigned long flags;
2683 
2684 	switch (csr_offset) {
2685 	case CSR_STATE_CLEAR:
2686 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2687 			reg_write(ohci, OHCI1394_LinkControlClear,
2688 				  OHCI1394_LinkControl_cycleMaster);
2689 			flush_writes(ohci);
2690 		}
2691 		if (value & CSR_STATE_BIT_ABDICATE)
2692 			ohci->csr_state_setclear_abdicate = false;
2693 		break;
2694 
2695 	case CSR_STATE_SET:
2696 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2697 			reg_write(ohci, OHCI1394_LinkControlSet,
2698 				  OHCI1394_LinkControl_cycleMaster);
2699 			flush_writes(ohci);
2700 		}
2701 		if (value & CSR_STATE_BIT_ABDICATE)
2702 			ohci->csr_state_setclear_abdicate = true;
2703 		break;
2704 
2705 	case CSR_NODE_IDS:
2706 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2707 		flush_writes(ohci);
2708 		break;
2709 
2710 	case CSR_CYCLE_TIME:
2711 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2712 		reg_write(ohci, OHCI1394_IntEventSet,
2713 			  OHCI1394_cycleInconsistent);
2714 		flush_writes(ohci);
2715 		break;
2716 
2717 	case CSR_BUS_TIME:
2718 		spin_lock_irqsave(&ohci->lock, flags);
2719 		ohci->bus_time = (update_bus_time(ohci) & 0x40) |
2720 		                 (value & ~0x7f);
2721 		spin_unlock_irqrestore(&ohci->lock, flags);
2722 		break;
2723 
2724 	case CSR_BUSY_TIMEOUT:
2725 		value = (value & 0xf) | ((value & 0xf) << 4) |
2726 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2727 		reg_write(ohci, OHCI1394_ATRetries, value);
2728 		flush_writes(ohci);
2729 		break;
2730 
2731 	case CSR_PRIORITY_BUDGET:
2732 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2733 		flush_writes(ohci);
2734 		break;
2735 
2736 	default:
2737 		WARN_ON(1);
2738 		break;
2739 	}
2740 }
2741 
2742 static void flush_iso_completions(struct iso_context *ctx)
2743 {
2744 	ctx->base.callback.sc(&ctx->base, ctx->last_timestamp,
2745 			      ctx->header_length, ctx->header,
2746 			      ctx->base.callback_data);
2747 	ctx->header_length = 0;
2748 }
2749 
2750 static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
2751 {
2752 	u32 *ctx_hdr;
2753 
2754 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
2755 		if (ctx->base.drop_overflow_headers)
2756 			return;
2757 		flush_iso_completions(ctx);
2758 	}
2759 
2760 	ctx_hdr = ctx->header + ctx->header_length;
2761 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
2762 
2763 	/*
2764 	 * The two iso header quadlets are byteswapped to little
2765 	 * endian by the controller, but we want to present them
2766 	 * as big endian for consistency with the bus endianness.
2767 	 */
2768 	if (ctx->base.header_size > 0)
2769 		ctx_hdr[0] = swab32(dma_hdr[1]); /* iso packet header */
2770 	if (ctx->base.header_size > 4)
2771 		ctx_hdr[1] = swab32(dma_hdr[0]); /* timestamp */
2772 	if (ctx->base.header_size > 8)
2773 		memcpy(&ctx_hdr[2], &dma_hdr[2], ctx->base.header_size - 8);
2774 	ctx->header_length += ctx->base.header_size;
2775 }
2776 
2777 static int handle_ir_packet_per_buffer(struct context *context,
2778 				       struct descriptor *d,
2779 				       struct descriptor *last)
2780 {
2781 	struct iso_context *ctx =
2782 		container_of(context, struct iso_context, context);
2783 	struct descriptor *pd;
2784 	u32 buffer_dma;
2785 
2786 	for (pd = d; pd <= last; pd++)
2787 		if (pd->transfer_status)
2788 			break;
2789 	if (pd > last)
2790 		/* Descriptor(s) not done yet, stop iteration */
2791 		return 0;
2792 
2793 	while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
2794 		d++;
2795 		buffer_dma = le32_to_cpu(d->data_address);
2796 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2797 					      buffer_dma & PAGE_MASK,
2798 					      buffer_dma & ~PAGE_MASK,
2799 					      le16_to_cpu(d->req_count),
2800 					      DMA_FROM_DEVICE);
2801 	}
2802 
2803 	copy_iso_headers(ctx, (u32 *) (last + 1));
2804 
2805 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2806 		flush_iso_completions(ctx);
2807 
2808 	return 1;
2809 }
2810 
2811 /* d == last because each descriptor block is only a single descriptor. */
2812 static int handle_ir_buffer_fill(struct context *context,
2813 				 struct descriptor *d,
2814 				 struct descriptor *last)
2815 {
2816 	struct iso_context *ctx =
2817 		container_of(context, struct iso_context, context);
2818 	unsigned int req_count, res_count, completed;
2819 	u32 buffer_dma;
2820 
2821 	req_count = le16_to_cpu(last->req_count);
2822 	res_count = le16_to_cpu(ACCESS_ONCE(last->res_count));
2823 	completed = req_count - res_count;
2824 	buffer_dma = le32_to_cpu(last->data_address);
2825 
2826 	if (completed > 0) {
2827 		ctx->mc_buffer_bus = buffer_dma;
2828 		ctx->mc_completed = completed;
2829 	}
2830 
2831 	if (res_count != 0)
2832 		/* Descriptor(s) not done yet, stop iteration */
2833 		return 0;
2834 
2835 	dma_sync_single_range_for_cpu(context->ohci->card.device,
2836 				      buffer_dma & PAGE_MASK,
2837 				      buffer_dma & ~PAGE_MASK,
2838 				      completed, DMA_FROM_DEVICE);
2839 
2840 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) {
2841 		ctx->base.callback.mc(&ctx->base,
2842 				      buffer_dma + completed,
2843 				      ctx->base.callback_data);
2844 		ctx->mc_completed = 0;
2845 	}
2846 
2847 	return 1;
2848 }
2849 
2850 static void flush_ir_buffer_fill(struct iso_context *ctx)
2851 {
2852 	dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
2853 				      ctx->mc_buffer_bus & PAGE_MASK,
2854 				      ctx->mc_buffer_bus & ~PAGE_MASK,
2855 				      ctx->mc_completed, DMA_FROM_DEVICE);
2856 
2857 	ctx->base.callback.mc(&ctx->base,
2858 			      ctx->mc_buffer_bus + ctx->mc_completed,
2859 			      ctx->base.callback_data);
2860 	ctx->mc_completed = 0;
2861 }
2862 
2863 static inline void sync_it_packet_for_cpu(struct context *context,
2864 					  struct descriptor *pd)
2865 {
2866 	__le16 control;
2867 	u32 buffer_dma;
2868 
2869 	/* only packets beginning with OUTPUT_MORE* have data buffers */
2870 	if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2871 		return;
2872 
2873 	/* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
2874 	pd += 2;
2875 
2876 	/*
2877 	 * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
2878 	 * data buffer is in the context program's coherent page and must not
2879 	 * be synced.
2880 	 */
2881 	if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
2882 	    (context->current_bus          & PAGE_MASK)) {
2883 		if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2884 			return;
2885 		pd++;
2886 	}
2887 
2888 	do {
2889 		buffer_dma = le32_to_cpu(pd->data_address);
2890 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2891 					      buffer_dma & PAGE_MASK,
2892 					      buffer_dma & ~PAGE_MASK,
2893 					      le16_to_cpu(pd->req_count),
2894 					      DMA_TO_DEVICE);
2895 		control = pd->control;
2896 		pd++;
2897 	} while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
2898 }
2899 
2900 static int handle_it_packet(struct context *context,
2901 			    struct descriptor *d,
2902 			    struct descriptor *last)
2903 {
2904 	struct iso_context *ctx =
2905 		container_of(context, struct iso_context, context);
2906 	struct descriptor *pd;
2907 	__be32 *ctx_hdr;
2908 
2909 	for (pd = d; pd <= last; pd++)
2910 		if (pd->transfer_status)
2911 			break;
2912 	if (pd > last)
2913 		/* Descriptor(s) not done yet, stop iteration */
2914 		return 0;
2915 
2916 	sync_it_packet_for_cpu(context, d);
2917 
2918 	if (ctx->header_length + 4 > PAGE_SIZE) {
2919 		if (ctx->base.drop_overflow_headers)
2920 			return 1;
2921 		flush_iso_completions(ctx);
2922 	}
2923 
2924 	ctx_hdr = ctx->header + ctx->header_length;
2925 	ctx->last_timestamp = le16_to_cpu(last->res_count);
2926 	/* Present this value as big-endian to match the receive code */
2927 	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
2928 			       le16_to_cpu(pd->res_count));
2929 	ctx->header_length += 4;
2930 
2931 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2932 		flush_iso_completions(ctx);
2933 
2934 	return 1;
2935 }
2936 
2937 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2938 {
2939 	u32 hi = channels >> 32, lo = channels;
2940 
2941 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2942 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2943 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2944 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2945 	mmiowb();
2946 	ohci->mc_channels = channels;
2947 }
2948 
2949 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2950 				int type, int channel, size_t header_size)
2951 {
2952 	struct fw_ohci *ohci = fw_ohci(card);
2953 	struct iso_context *uninitialized_var(ctx);
2954 	descriptor_callback_t uninitialized_var(callback);
2955 	u64 *uninitialized_var(channels);
2956 	u32 *uninitialized_var(mask), uninitialized_var(regs);
2957 	int index, ret = -EBUSY;
2958 
2959 	spin_lock_irq(&ohci->lock);
2960 
2961 	switch (type) {
2962 	case FW_ISO_CONTEXT_TRANSMIT:
2963 		mask     = &ohci->it_context_mask;
2964 		callback = handle_it_packet;
2965 		index    = ffs(*mask) - 1;
2966 		if (index >= 0) {
2967 			*mask &= ~(1 << index);
2968 			regs = OHCI1394_IsoXmitContextBase(index);
2969 			ctx  = &ohci->it_context_list[index];
2970 		}
2971 		break;
2972 
2973 	case FW_ISO_CONTEXT_RECEIVE:
2974 		channels = &ohci->ir_context_channels;
2975 		mask     = &ohci->ir_context_mask;
2976 		callback = handle_ir_packet_per_buffer;
2977 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2978 		if (index >= 0) {
2979 			*channels &= ~(1ULL << channel);
2980 			*mask     &= ~(1 << index);
2981 			regs = OHCI1394_IsoRcvContextBase(index);
2982 			ctx  = &ohci->ir_context_list[index];
2983 		}
2984 		break;
2985 
2986 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2987 		mask     = &ohci->ir_context_mask;
2988 		callback = handle_ir_buffer_fill;
2989 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2990 		if (index >= 0) {
2991 			ohci->mc_allocated = true;
2992 			*mask &= ~(1 << index);
2993 			regs = OHCI1394_IsoRcvContextBase(index);
2994 			ctx  = &ohci->ir_context_list[index];
2995 		}
2996 		break;
2997 
2998 	default:
2999 		index = -1;
3000 		ret = -ENOSYS;
3001 	}
3002 
3003 	spin_unlock_irq(&ohci->lock);
3004 
3005 	if (index < 0)
3006 		return ERR_PTR(ret);
3007 
3008 	memset(ctx, 0, sizeof(*ctx));
3009 	ctx->header_length = 0;
3010 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
3011 	if (ctx->header == NULL) {
3012 		ret = -ENOMEM;
3013 		goto out;
3014 	}
3015 	ret = context_init(&ctx->context, ohci, regs, callback);
3016 	if (ret < 0)
3017 		goto out_with_header;
3018 
3019 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
3020 		set_multichannel_mask(ohci, 0);
3021 		ctx->mc_completed = 0;
3022 	}
3023 
3024 	return &ctx->base;
3025 
3026  out_with_header:
3027 	free_page((unsigned long)ctx->header);
3028  out:
3029 	spin_lock_irq(&ohci->lock);
3030 
3031 	switch (type) {
3032 	case FW_ISO_CONTEXT_RECEIVE:
3033 		*channels |= 1ULL << channel;
3034 		break;
3035 
3036 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3037 		ohci->mc_allocated = false;
3038 		break;
3039 	}
3040 	*mask |= 1 << index;
3041 
3042 	spin_unlock_irq(&ohci->lock);
3043 
3044 	return ERR_PTR(ret);
3045 }
3046 
3047 static int ohci_start_iso(struct fw_iso_context *base,
3048 			  s32 cycle, u32 sync, u32 tags)
3049 {
3050 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3051 	struct fw_ohci *ohci = ctx->context.ohci;
3052 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
3053 	int index;
3054 
3055 	/* the controller cannot start without any queued packets */
3056 	if (ctx->context.last->branch_address == 0)
3057 		return -ENODATA;
3058 
3059 	switch (ctx->base.type) {
3060 	case FW_ISO_CONTEXT_TRANSMIT:
3061 		index = ctx - ohci->it_context_list;
3062 		match = 0;
3063 		if (cycle >= 0)
3064 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
3065 				(cycle & 0x7fff) << 16;
3066 
3067 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
3068 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
3069 		context_run(&ctx->context, match);
3070 		break;
3071 
3072 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3073 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
3074 		/* fall through */
3075 	case FW_ISO_CONTEXT_RECEIVE:
3076 		index = ctx - ohci->ir_context_list;
3077 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
3078 		if (cycle >= 0) {
3079 			match |= (cycle & 0x07fff) << 12;
3080 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
3081 		}
3082 
3083 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
3084 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
3085 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
3086 		context_run(&ctx->context, control);
3087 
3088 		ctx->sync = sync;
3089 		ctx->tags = tags;
3090 
3091 		break;
3092 	}
3093 
3094 	return 0;
3095 }
3096 
3097 static int ohci_stop_iso(struct fw_iso_context *base)
3098 {
3099 	struct fw_ohci *ohci = fw_ohci(base->card);
3100 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3101 	int index;
3102 
3103 	switch (ctx->base.type) {
3104 	case FW_ISO_CONTEXT_TRANSMIT:
3105 		index = ctx - ohci->it_context_list;
3106 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
3107 		break;
3108 
3109 	case FW_ISO_CONTEXT_RECEIVE:
3110 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3111 		index = ctx - ohci->ir_context_list;
3112 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
3113 		break;
3114 	}
3115 	flush_writes(ohci);
3116 	context_stop(&ctx->context);
3117 	tasklet_kill(&ctx->context.tasklet);
3118 
3119 	return 0;
3120 }
3121 
3122 static void ohci_free_iso_context(struct fw_iso_context *base)
3123 {
3124 	struct fw_ohci *ohci = fw_ohci(base->card);
3125 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3126 	unsigned long flags;
3127 	int index;
3128 
3129 	ohci_stop_iso(base);
3130 	context_release(&ctx->context);
3131 	free_page((unsigned long)ctx->header);
3132 
3133 	spin_lock_irqsave(&ohci->lock, flags);
3134 
3135 	switch (base->type) {
3136 	case FW_ISO_CONTEXT_TRANSMIT:
3137 		index = ctx - ohci->it_context_list;
3138 		ohci->it_context_mask |= 1 << index;
3139 		break;
3140 
3141 	case FW_ISO_CONTEXT_RECEIVE:
3142 		index = ctx - ohci->ir_context_list;
3143 		ohci->ir_context_mask |= 1 << index;
3144 		ohci->ir_context_channels |= 1ULL << base->channel;
3145 		break;
3146 
3147 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3148 		index = ctx - ohci->ir_context_list;
3149 		ohci->ir_context_mask |= 1 << index;
3150 		ohci->ir_context_channels |= ohci->mc_channels;
3151 		ohci->mc_channels = 0;
3152 		ohci->mc_allocated = false;
3153 		break;
3154 	}
3155 
3156 	spin_unlock_irqrestore(&ohci->lock, flags);
3157 }
3158 
3159 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
3160 {
3161 	struct fw_ohci *ohci = fw_ohci(base->card);
3162 	unsigned long flags;
3163 	int ret;
3164 
3165 	switch (base->type) {
3166 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3167 
3168 		spin_lock_irqsave(&ohci->lock, flags);
3169 
3170 		/* Don't allow multichannel to grab other contexts' channels. */
3171 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
3172 			*channels = ohci->ir_context_channels;
3173 			ret = -EBUSY;
3174 		} else {
3175 			set_multichannel_mask(ohci, *channels);
3176 			ret = 0;
3177 		}
3178 
3179 		spin_unlock_irqrestore(&ohci->lock, flags);
3180 
3181 		break;
3182 	default:
3183 		ret = -EINVAL;
3184 	}
3185 
3186 	return ret;
3187 }
3188 
3189 #ifdef CONFIG_PM
3190 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
3191 {
3192 	int i;
3193 	struct iso_context *ctx;
3194 
3195 	for (i = 0 ; i < ohci->n_ir ; i++) {
3196 		ctx = &ohci->ir_context_list[i];
3197 		if (ctx->context.running)
3198 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3199 	}
3200 
3201 	for (i = 0 ; i < ohci->n_it ; i++) {
3202 		ctx = &ohci->it_context_list[i];
3203 		if (ctx->context.running)
3204 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3205 	}
3206 }
3207 #endif
3208 
3209 static int queue_iso_transmit(struct iso_context *ctx,
3210 			      struct fw_iso_packet *packet,
3211 			      struct fw_iso_buffer *buffer,
3212 			      unsigned long payload)
3213 {
3214 	struct descriptor *d, *last, *pd;
3215 	struct fw_iso_packet *p;
3216 	__le32 *header;
3217 	dma_addr_t d_bus, page_bus;
3218 	u32 z, header_z, payload_z, irq;
3219 	u32 payload_index, payload_end_index, next_page_index;
3220 	int page, end_page, i, length, offset;
3221 
3222 	p = packet;
3223 	payload_index = payload;
3224 
3225 	if (p->skip)
3226 		z = 1;
3227 	else
3228 		z = 2;
3229 	if (p->header_length > 0)
3230 		z++;
3231 
3232 	/* Determine the first page the payload isn't contained in. */
3233 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
3234 	if (p->payload_length > 0)
3235 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
3236 	else
3237 		payload_z = 0;
3238 
3239 	z += payload_z;
3240 
3241 	/* Get header size in number of descriptors. */
3242 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
3243 
3244 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
3245 	if (d == NULL)
3246 		return -ENOMEM;
3247 
3248 	if (!p->skip) {
3249 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
3250 		d[0].req_count = cpu_to_le16(8);
3251 		/*
3252 		 * Link the skip address to this descriptor itself.  This causes
3253 		 * a context to skip a cycle whenever lost cycles or FIFO
3254 		 * overruns occur, without dropping the data.  The application
3255 		 * should then decide whether this is an error condition or not.
3256 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
3257 		 */
3258 		d[0].branch_address = cpu_to_le32(d_bus | z);
3259 
3260 		header = (__le32 *) &d[1];
3261 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
3262 					IT_HEADER_TAG(p->tag) |
3263 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
3264 					IT_HEADER_CHANNEL(ctx->base.channel) |
3265 					IT_HEADER_SPEED(ctx->base.speed));
3266 		header[1] =
3267 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
3268 							  p->payload_length));
3269 	}
3270 
3271 	if (p->header_length > 0) {
3272 		d[2].req_count    = cpu_to_le16(p->header_length);
3273 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
3274 		memcpy(&d[z], p->header, p->header_length);
3275 	}
3276 
3277 	pd = d + z - payload_z;
3278 	payload_end_index = payload_index + p->payload_length;
3279 	for (i = 0; i < payload_z; i++) {
3280 		page               = payload_index >> PAGE_SHIFT;
3281 		offset             = payload_index & ~PAGE_MASK;
3282 		next_page_index    = (page + 1) << PAGE_SHIFT;
3283 		length             =
3284 			min(next_page_index, payload_end_index) - payload_index;
3285 		pd[i].req_count    = cpu_to_le16(length);
3286 
3287 		page_bus = page_private(buffer->pages[page]);
3288 		pd[i].data_address = cpu_to_le32(page_bus + offset);
3289 
3290 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3291 						 page_bus, offset, length,
3292 						 DMA_TO_DEVICE);
3293 
3294 		payload_index += length;
3295 	}
3296 
3297 	if (p->interrupt)
3298 		irq = DESCRIPTOR_IRQ_ALWAYS;
3299 	else
3300 		irq = DESCRIPTOR_NO_IRQ;
3301 
3302 	last = z == 2 ? d : d + z - 1;
3303 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
3304 				     DESCRIPTOR_STATUS |
3305 				     DESCRIPTOR_BRANCH_ALWAYS |
3306 				     irq);
3307 
3308 	context_append(&ctx->context, d, z, header_z);
3309 
3310 	return 0;
3311 }
3312 
3313 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
3314 				       struct fw_iso_packet *packet,
3315 				       struct fw_iso_buffer *buffer,
3316 				       unsigned long payload)
3317 {
3318 	struct device *device = ctx->context.ohci->card.device;
3319 	struct descriptor *d, *pd;
3320 	dma_addr_t d_bus, page_bus;
3321 	u32 z, header_z, rest;
3322 	int i, j, length;
3323 	int page, offset, packet_count, header_size, payload_per_buffer;
3324 
3325 	/*
3326 	 * The OHCI controller puts the isochronous header and trailer in the
3327 	 * buffer, so we need at least 8 bytes.
3328 	 */
3329 	packet_count = packet->header_length / ctx->base.header_size;
3330 	header_size  = max(ctx->base.header_size, (size_t)8);
3331 
3332 	/* Get header size in number of descriptors. */
3333 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
3334 	page     = payload >> PAGE_SHIFT;
3335 	offset   = payload & ~PAGE_MASK;
3336 	payload_per_buffer = packet->payload_length / packet_count;
3337 
3338 	for (i = 0; i < packet_count; i++) {
3339 		/* d points to the header descriptor */
3340 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
3341 		d = context_get_descriptors(&ctx->context,
3342 				z + header_z, &d_bus);
3343 		if (d == NULL)
3344 			return -ENOMEM;
3345 
3346 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3347 					      DESCRIPTOR_INPUT_MORE);
3348 		if (packet->skip && i == 0)
3349 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3350 		d->req_count    = cpu_to_le16(header_size);
3351 		d->res_count    = d->req_count;
3352 		d->transfer_status = 0;
3353 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3354 
3355 		rest = payload_per_buffer;
3356 		pd = d;
3357 		for (j = 1; j < z; j++) {
3358 			pd++;
3359 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3360 						  DESCRIPTOR_INPUT_MORE);
3361 
3362 			if (offset + rest < PAGE_SIZE)
3363 				length = rest;
3364 			else
3365 				length = PAGE_SIZE - offset;
3366 			pd->req_count = cpu_to_le16(length);
3367 			pd->res_count = pd->req_count;
3368 			pd->transfer_status = 0;
3369 
3370 			page_bus = page_private(buffer->pages[page]);
3371 			pd->data_address = cpu_to_le32(page_bus + offset);
3372 
3373 			dma_sync_single_range_for_device(device, page_bus,
3374 							 offset, length,
3375 							 DMA_FROM_DEVICE);
3376 
3377 			offset = (offset + length) & ~PAGE_MASK;
3378 			rest -= length;
3379 			if (offset == 0)
3380 				page++;
3381 		}
3382 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3383 					  DESCRIPTOR_INPUT_LAST |
3384 					  DESCRIPTOR_BRANCH_ALWAYS);
3385 		if (packet->interrupt && i == packet_count - 1)
3386 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3387 
3388 		context_append(&ctx->context, d, z, header_z);
3389 	}
3390 
3391 	return 0;
3392 }
3393 
3394 static int queue_iso_buffer_fill(struct iso_context *ctx,
3395 				 struct fw_iso_packet *packet,
3396 				 struct fw_iso_buffer *buffer,
3397 				 unsigned long payload)
3398 {
3399 	struct descriptor *d;
3400 	dma_addr_t d_bus, page_bus;
3401 	int page, offset, rest, z, i, length;
3402 
3403 	page   = payload >> PAGE_SHIFT;
3404 	offset = payload & ~PAGE_MASK;
3405 	rest   = packet->payload_length;
3406 
3407 	/* We need one descriptor for each page in the buffer. */
3408 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3409 
3410 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3411 		return -EFAULT;
3412 
3413 	for (i = 0; i < z; i++) {
3414 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3415 		if (d == NULL)
3416 			return -ENOMEM;
3417 
3418 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3419 					 DESCRIPTOR_BRANCH_ALWAYS);
3420 		if (packet->skip && i == 0)
3421 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3422 		if (packet->interrupt && i == z - 1)
3423 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3424 
3425 		if (offset + rest < PAGE_SIZE)
3426 			length = rest;
3427 		else
3428 			length = PAGE_SIZE - offset;
3429 		d->req_count = cpu_to_le16(length);
3430 		d->res_count = d->req_count;
3431 		d->transfer_status = 0;
3432 
3433 		page_bus = page_private(buffer->pages[page]);
3434 		d->data_address = cpu_to_le32(page_bus + offset);
3435 
3436 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3437 						 page_bus, offset, length,
3438 						 DMA_FROM_DEVICE);
3439 
3440 		rest -= length;
3441 		offset = 0;
3442 		page++;
3443 
3444 		context_append(&ctx->context, d, 1, 0);
3445 	}
3446 
3447 	return 0;
3448 }
3449 
3450 static int ohci_queue_iso(struct fw_iso_context *base,
3451 			  struct fw_iso_packet *packet,
3452 			  struct fw_iso_buffer *buffer,
3453 			  unsigned long payload)
3454 {
3455 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3456 	unsigned long flags;
3457 	int ret = -ENOSYS;
3458 
3459 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3460 	switch (base->type) {
3461 	case FW_ISO_CONTEXT_TRANSMIT:
3462 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3463 		break;
3464 	case FW_ISO_CONTEXT_RECEIVE:
3465 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3466 		break;
3467 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3468 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3469 		break;
3470 	}
3471 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3472 
3473 	return ret;
3474 }
3475 
3476 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3477 {
3478 	struct context *ctx =
3479 			&container_of(base, struct iso_context, base)->context;
3480 
3481 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3482 }
3483 
3484 static int ohci_flush_iso_completions(struct fw_iso_context *base)
3485 {
3486 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3487 	int ret = 0;
3488 
3489 	tasklet_disable(&ctx->context.tasklet);
3490 
3491 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
3492 		context_tasklet((unsigned long)&ctx->context);
3493 
3494 		switch (base->type) {
3495 		case FW_ISO_CONTEXT_TRANSMIT:
3496 		case FW_ISO_CONTEXT_RECEIVE:
3497 			if (ctx->header_length != 0)
3498 				flush_iso_completions(ctx);
3499 			break;
3500 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3501 			if (ctx->mc_completed != 0)
3502 				flush_ir_buffer_fill(ctx);
3503 			break;
3504 		default:
3505 			ret = -ENOSYS;
3506 		}
3507 
3508 		clear_bit_unlock(0, &ctx->flushing_completions);
3509 		smp_mb__after_clear_bit();
3510 	}
3511 
3512 	tasklet_enable(&ctx->context.tasklet);
3513 
3514 	return ret;
3515 }
3516 
3517 static const struct fw_card_driver ohci_driver = {
3518 	.enable			= ohci_enable,
3519 	.read_phy_reg		= ohci_read_phy_reg,
3520 	.update_phy_reg		= ohci_update_phy_reg,
3521 	.set_config_rom		= ohci_set_config_rom,
3522 	.send_request		= ohci_send_request,
3523 	.send_response		= ohci_send_response,
3524 	.cancel_packet		= ohci_cancel_packet,
3525 	.enable_phys_dma	= ohci_enable_phys_dma,
3526 	.read_csr		= ohci_read_csr,
3527 	.write_csr		= ohci_write_csr,
3528 
3529 	.allocate_iso_context	= ohci_allocate_iso_context,
3530 	.free_iso_context	= ohci_free_iso_context,
3531 	.set_iso_channels	= ohci_set_iso_channels,
3532 	.queue_iso		= ohci_queue_iso,
3533 	.flush_queue_iso	= ohci_flush_queue_iso,
3534 	.flush_iso_completions	= ohci_flush_iso_completions,
3535 	.start_iso		= ohci_start_iso,
3536 	.stop_iso		= ohci_stop_iso,
3537 };
3538 
3539 #ifdef CONFIG_PPC_PMAC
3540 static void pmac_ohci_on(struct pci_dev *dev)
3541 {
3542 	if (machine_is(powermac)) {
3543 		struct device_node *ofn = pci_device_to_OF_node(dev);
3544 
3545 		if (ofn) {
3546 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3547 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3548 		}
3549 	}
3550 }
3551 
3552 static void pmac_ohci_off(struct pci_dev *dev)
3553 {
3554 	if (machine_is(powermac)) {
3555 		struct device_node *ofn = pci_device_to_OF_node(dev);
3556 
3557 		if (ofn) {
3558 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3559 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3560 		}
3561 	}
3562 }
3563 #else
3564 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3565 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3566 #endif /* CONFIG_PPC_PMAC */
3567 
3568 static int pci_probe(struct pci_dev *dev,
3569 			       const struct pci_device_id *ent)
3570 {
3571 	struct fw_ohci *ohci;
3572 	u32 bus_options, max_receive, link_speed, version;
3573 	u64 guid;
3574 	int i, err;
3575 	size_t size;
3576 
3577 	if (dev->vendor == PCI_VENDOR_ID_PINNACLE_SYSTEMS) {
3578 		dev_err(&dev->dev, "Pinnacle MovieBoard is not yet supported\n");
3579 		return -ENOSYS;
3580 	}
3581 
3582 	ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3583 	if (ohci == NULL) {
3584 		err = -ENOMEM;
3585 		goto fail;
3586 	}
3587 
3588 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3589 
3590 	pmac_ohci_on(dev);
3591 
3592 	err = pci_enable_device(dev);
3593 	if (err) {
3594 		dev_err(&dev->dev, "failed to enable OHCI hardware\n");
3595 		goto fail_free;
3596 	}
3597 
3598 	pci_set_master(dev);
3599 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3600 	pci_set_drvdata(dev, ohci);
3601 
3602 	spin_lock_init(&ohci->lock);
3603 	mutex_init(&ohci->phy_reg_mutex);
3604 
3605 	INIT_WORK(&ohci->bus_reset_work, bus_reset_work);
3606 
3607 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM) ||
3608 	    pci_resource_len(dev, 0) < OHCI1394_REGISTER_SIZE) {
3609 		ohci_err(ohci, "invalid MMIO resource\n");
3610 		err = -ENXIO;
3611 		goto fail_disable;
3612 	}
3613 
3614 	err = pci_request_region(dev, 0, ohci_driver_name);
3615 	if (err) {
3616 		ohci_err(ohci, "MMIO resource unavailable\n");
3617 		goto fail_disable;
3618 	}
3619 
3620 	ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3621 	if (ohci->registers == NULL) {
3622 		ohci_err(ohci, "failed to remap registers\n");
3623 		err = -ENXIO;
3624 		goto fail_iomem;
3625 	}
3626 
3627 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3628 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3629 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3630 		     ohci_quirks[i].device == dev->device) &&
3631 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3632 		     ohci_quirks[i].revision >= dev->revision)) {
3633 			ohci->quirks = ohci_quirks[i].flags;
3634 			break;
3635 		}
3636 	if (param_quirks)
3637 		ohci->quirks = param_quirks;
3638 
3639 	/*
3640 	 * Because dma_alloc_coherent() allocates at least one page,
3641 	 * we save space by using a common buffer for the AR request/
3642 	 * response descriptors and the self IDs buffer.
3643 	 */
3644 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3645 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3646 	ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3647 					       PAGE_SIZE,
3648 					       &ohci->misc_buffer_bus,
3649 					       GFP_KERNEL);
3650 	if (!ohci->misc_buffer) {
3651 		err = -ENOMEM;
3652 		goto fail_iounmap;
3653 	}
3654 
3655 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3656 			      OHCI1394_AsReqRcvContextControlSet);
3657 	if (err < 0)
3658 		goto fail_misc_buf;
3659 
3660 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3661 			      OHCI1394_AsRspRcvContextControlSet);
3662 	if (err < 0)
3663 		goto fail_arreq_ctx;
3664 
3665 	err = context_init(&ohci->at_request_ctx, ohci,
3666 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3667 	if (err < 0)
3668 		goto fail_arrsp_ctx;
3669 
3670 	err = context_init(&ohci->at_response_ctx, ohci,
3671 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3672 	if (err < 0)
3673 		goto fail_atreq_ctx;
3674 
3675 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3676 	ohci->ir_context_channels = ~0ULL;
3677 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3678 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3679 	ohci->ir_context_mask = ohci->ir_context_support;
3680 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3681 	size = sizeof(struct iso_context) * ohci->n_ir;
3682 	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3683 
3684 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3685 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3686 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3687 	ohci->it_context_mask = ohci->it_context_support;
3688 	ohci->n_it = hweight32(ohci->it_context_mask);
3689 	size = sizeof(struct iso_context) * ohci->n_it;
3690 	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3691 
3692 	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3693 		err = -ENOMEM;
3694 		goto fail_contexts;
3695 	}
3696 
3697 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
3698 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3699 
3700 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3701 	max_receive = (bus_options >> 12) & 0xf;
3702 	link_speed = bus_options & 0x7;
3703 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3704 		reg_read(ohci, OHCI1394_GUIDLo);
3705 
3706 	if (!(ohci->quirks & QUIRK_NO_MSI))
3707 		pci_enable_msi(dev);
3708 	if (request_irq(dev->irq, irq_handler,
3709 			pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
3710 			ohci_driver_name, ohci)) {
3711 		ohci_err(ohci, "failed to allocate interrupt %d\n", dev->irq);
3712 		err = -EIO;
3713 		goto fail_msi;
3714 	}
3715 
3716 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3717 	if (err)
3718 		goto fail_irq;
3719 
3720 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3721 	ohci_notice(ohci,
3722 		    "added OHCI v%x.%x device as card %d, "
3723 		    "%d IR + %d IT contexts, quirks 0x%x\n",
3724 		    version >> 16, version & 0xff, ohci->card.index,
3725 		    ohci->n_ir, ohci->n_it, ohci->quirks);
3726 
3727 	return 0;
3728 
3729  fail_irq:
3730 	free_irq(dev->irq, ohci);
3731  fail_msi:
3732 	pci_disable_msi(dev);
3733  fail_contexts:
3734 	kfree(ohci->ir_context_list);
3735 	kfree(ohci->it_context_list);
3736 	context_release(&ohci->at_response_ctx);
3737  fail_atreq_ctx:
3738 	context_release(&ohci->at_request_ctx);
3739  fail_arrsp_ctx:
3740 	ar_context_release(&ohci->ar_response_ctx);
3741  fail_arreq_ctx:
3742 	ar_context_release(&ohci->ar_request_ctx);
3743  fail_misc_buf:
3744 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3745 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3746  fail_iounmap:
3747 	pci_iounmap(dev, ohci->registers);
3748  fail_iomem:
3749 	pci_release_region(dev, 0);
3750  fail_disable:
3751 	pci_disable_device(dev);
3752  fail_free:
3753 	kfree(ohci);
3754 	pmac_ohci_off(dev);
3755  fail:
3756 	return err;
3757 }
3758 
3759 static void pci_remove(struct pci_dev *dev)
3760 {
3761 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3762 
3763 	/*
3764 	 * If the removal is happening from the suspend state, LPS won't be
3765 	 * enabled and host registers (eg., IntMaskClear) won't be accessible.
3766 	 */
3767 	if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) {
3768 		reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3769 		flush_writes(ohci);
3770 	}
3771 	cancel_work_sync(&ohci->bus_reset_work);
3772 	fw_core_remove_card(&ohci->card);
3773 
3774 	/*
3775 	 * FIXME: Fail all pending packets here, now that the upper
3776 	 * layers can't queue any more.
3777 	 */
3778 
3779 	software_reset(ohci);
3780 	free_irq(dev->irq, ohci);
3781 
3782 	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3783 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3784 				  ohci->next_config_rom, ohci->next_config_rom_bus);
3785 	if (ohci->config_rom)
3786 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3787 				  ohci->config_rom, ohci->config_rom_bus);
3788 	ar_context_release(&ohci->ar_request_ctx);
3789 	ar_context_release(&ohci->ar_response_ctx);
3790 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3791 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3792 	context_release(&ohci->at_request_ctx);
3793 	context_release(&ohci->at_response_ctx);
3794 	kfree(ohci->it_context_list);
3795 	kfree(ohci->ir_context_list);
3796 	pci_disable_msi(dev);
3797 	pci_iounmap(dev, ohci->registers);
3798 	pci_release_region(dev, 0);
3799 	pci_disable_device(dev);
3800 	kfree(ohci);
3801 	pmac_ohci_off(dev);
3802 
3803 	dev_notice(&dev->dev, "removed fw-ohci device\n");
3804 }
3805 
3806 #ifdef CONFIG_PM
3807 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3808 {
3809 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3810 	int err;
3811 
3812 	software_reset(ohci);
3813 	err = pci_save_state(dev);
3814 	if (err) {
3815 		ohci_err(ohci, "pci_save_state failed\n");
3816 		return err;
3817 	}
3818 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3819 	if (err)
3820 		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
3821 	pmac_ohci_off(dev);
3822 
3823 	return 0;
3824 }
3825 
3826 static int pci_resume(struct pci_dev *dev)
3827 {
3828 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3829 	int err;
3830 
3831 	pmac_ohci_on(dev);
3832 	pci_set_power_state(dev, PCI_D0);
3833 	pci_restore_state(dev);
3834 	err = pci_enable_device(dev);
3835 	if (err) {
3836 		ohci_err(ohci, "pci_enable_device failed\n");
3837 		return err;
3838 	}
3839 
3840 	/* Some systems don't setup GUID register on resume from ram  */
3841 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3842 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3843 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3844 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3845 	}
3846 
3847 	err = ohci_enable(&ohci->card, NULL, 0);
3848 	if (err)
3849 		return err;
3850 
3851 	ohci_resume_iso_dma(ohci);
3852 
3853 	return 0;
3854 }
3855 #endif
3856 
3857 static const struct pci_device_id pci_table[] = {
3858 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3859 	{ }
3860 };
3861 
3862 MODULE_DEVICE_TABLE(pci, pci_table);
3863 
3864 static struct pci_driver fw_ohci_pci_driver = {
3865 	.name		= ohci_driver_name,
3866 	.id_table	= pci_table,
3867 	.probe		= pci_probe,
3868 	.remove		= pci_remove,
3869 #ifdef CONFIG_PM
3870 	.resume		= pci_resume,
3871 	.suspend	= pci_suspend,
3872 #endif
3873 };
3874 
3875 static int __init fw_ohci_init(void)
3876 {
3877 	selfid_workqueue = alloc_workqueue(KBUILD_MODNAME, WQ_MEM_RECLAIM, 0);
3878 	if (!selfid_workqueue)
3879 		return -ENOMEM;
3880 
3881 	return pci_register_driver(&fw_ohci_pci_driver);
3882 }
3883 
3884 static void __exit fw_ohci_cleanup(void)
3885 {
3886 	pci_unregister_driver(&fw_ohci_pci_driver);
3887 	destroy_workqueue(selfid_workqueue);
3888 }
3889 
3890 module_init(fw_ohci_init);
3891 module_exit(fw_ohci_cleanup);
3892 
3893 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3894 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3895 MODULE_LICENSE("GPL");
3896 
3897 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3898 MODULE_ALIAS("ohci1394");
3899