xref: /openbmc/linux/drivers/firewire/ohci.c (revision d2168146)
1 /*
2  * Driver for OHCI 1394 controllers
3  *
4  * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 #include <linux/bitops.h>
22 #include <linux/bug.h>
23 #include <linux/compiler.h>
24 #include <linux/delay.h>
25 #include <linux/device.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/firewire.h>
28 #include <linux/firewire-constants.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/io.h>
32 #include <linux/kernel.h>
33 #include <linux/list.h>
34 #include <linux/mm.h>
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/mutex.h>
38 #include <linux/pci.h>
39 #include <linux/pci_ids.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/string.h>
43 #include <linux/time.h>
44 #include <linux/vmalloc.h>
45 #include <linux/workqueue.h>
46 
47 #include <asm/byteorder.h>
48 #include <asm/page.h>
49 
50 #ifdef CONFIG_PPC_PMAC
51 #include <asm/pmac_feature.h>
52 #endif
53 
54 #include "core.h"
55 #include "ohci.h"
56 
57 #define ohci_info(ohci, f, args...)	dev_info(ohci->card.device, f, ##args)
58 #define ohci_notice(ohci, f, args...)	dev_notice(ohci->card.device, f, ##args)
59 #define ohci_err(ohci, f, args...)	dev_err(ohci->card.device, f, ##args)
60 
61 #define DESCRIPTOR_OUTPUT_MORE		0
62 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
63 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
64 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
65 #define DESCRIPTOR_STATUS		(1 << 11)
66 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
67 #define DESCRIPTOR_PING			(1 << 7)
68 #define DESCRIPTOR_YY			(1 << 6)
69 #define DESCRIPTOR_NO_IRQ		(0 << 4)
70 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
71 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
72 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
73 #define DESCRIPTOR_WAIT			(3 << 0)
74 
75 #define DESCRIPTOR_CMD			(0xf << 12)
76 
77 struct descriptor {
78 	__le16 req_count;
79 	__le16 control;
80 	__le32 data_address;
81 	__le32 branch_address;
82 	__le16 res_count;
83 	__le16 transfer_status;
84 } __attribute__((aligned(16)));
85 
86 #define CONTROL_SET(regs)	(regs)
87 #define CONTROL_CLEAR(regs)	((regs) + 4)
88 #define COMMAND_PTR(regs)	((regs) + 12)
89 #define CONTEXT_MATCH(regs)	((regs) + 16)
90 
91 #define AR_BUFFER_SIZE	(32*1024)
92 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
93 /* we need at least two pages for proper list management */
94 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
95 
96 #define MAX_ASYNC_PAYLOAD	4096
97 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
98 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
99 
100 struct ar_context {
101 	struct fw_ohci *ohci;
102 	struct page *pages[AR_BUFFERS];
103 	void *buffer;
104 	struct descriptor *descriptors;
105 	dma_addr_t descriptors_bus;
106 	void *pointer;
107 	unsigned int last_buffer_index;
108 	u32 regs;
109 	struct tasklet_struct tasklet;
110 };
111 
112 struct context;
113 
114 typedef int (*descriptor_callback_t)(struct context *ctx,
115 				     struct descriptor *d,
116 				     struct descriptor *last);
117 
118 /*
119  * A buffer that contains a block of DMA-able coherent memory used for
120  * storing a portion of a DMA descriptor program.
121  */
122 struct descriptor_buffer {
123 	struct list_head list;
124 	dma_addr_t buffer_bus;
125 	size_t buffer_size;
126 	size_t used;
127 	struct descriptor buffer[0];
128 };
129 
130 struct context {
131 	struct fw_ohci *ohci;
132 	u32 regs;
133 	int total_allocation;
134 	u32 current_bus;
135 	bool running;
136 	bool flushing;
137 
138 	/*
139 	 * List of page-sized buffers for storing DMA descriptors.
140 	 * Head of list contains buffers in use and tail of list contains
141 	 * free buffers.
142 	 */
143 	struct list_head buffer_list;
144 
145 	/*
146 	 * Pointer to a buffer inside buffer_list that contains the tail
147 	 * end of the current DMA program.
148 	 */
149 	struct descriptor_buffer *buffer_tail;
150 
151 	/*
152 	 * The descriptor containing the branch address of the first
153 	 * descriptor that has not yet been filled by the device.
154 	 */
155 	struct descriptor *last;
156 
157 	/*
158 	 * The last descriptor block in the DMA program. It contains the branch
159 	 * address that must be updated upon appending a new descriptor.
160 	 */
161 	struct descriptor *prev;
162 	int prev_z;
163 
164 	descriptor_callback_t callback;
165 
166 	struct tasklet_struct tasklet;
167 };
168 
169 #define IT_HEADER_SY(v)          ((v) <<  0)
170 #define IT_HEADER_TCODE(v)       ((v) <<  4)
171 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
172 #define IT_HEADER_TAG(v)         ((v) << 14)
173 #define IT_HEADER_SPEED(v)       ((v) << 16)
174 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
175 
176 struct iso_context {
177 	struct fw_iso_context base;
178 	struct context context;
179 	void *header;
180 	size_t header_length;
181 	unsigned long flushing_completions;
182 	u32 mc_buffer_bus;
183 	u16 mc_completed;
184 	u16 last_timestamp;
185 	u8 sync;
186 	u8 tags;
187 };
188 
189 #define CONFIG_ROM_SIZE 1024
190 
191 struct fw_ohci {
192 	struct fw_card card;
193 
194 	__iomem char *registers;
195 	int node_id;
196 	int generation;
197 	int request_generation;	/* for timestamping incoming requests */
198 	unsigned quirks;
199 	unsigned int pri_req_max;
200 	u32 bus_time;
201 	bool bus_time_running;
202 	bool is_root;
203 	bool csr_state_setclear_abdicate;
204 	int n_ir;
205 	int n_it;
206 	/*
207 	 * Spinlock for accessing fw_ohci data.  Never call out of
208 	 * this driver with this lock held.
209 	 */
210 	spinlock_t lock;
211 
212 	struct mutex phy_reg_mutex;
213 
214 	void *misc_buffer;
215 	dma_addr_t misc_buffer_bus;
216 
217 	struct ar_context ar_request_ctx;
218 	struct ar_context ar_response_ctx;
219 	struct context at_request_ctx;
220 	struct context at_response_ctx;
221 
222 	u32 it_context_support;
223 	u32 it_context_mask;     /* unoccupied IT contexts */
224 	struct iso_context *it_context_list;
225 	u64 ir_context_channels; /* unoccupied channels */
226 	u32 ir_context_support;
227 	u32 ir_context_mask;     /* unoccupied IR contexts */
228 	struct iso_context *ir_context_list;
229 	u64 mc_channels; /* channels in use by the multichannel IR context */
230 	bool mc_allocated;
231 
232 	__be32    *config_rom;
233 	dma_addr_t config_rom_bus;
234 	__be32    *next_config_rom;
235 	dma_addr_t next_config_rom_bus;
236 	__be32     next_header;
237 
238 	__le32    *self_id;
239 	dma_addr_t self_id_bus;
240 	struct work_struct bus_reset_work;
241 
242 	u32 self_id_buffer[512];
243 };
244 
245 static struct workqueue_struct *selfid_workqueue;
246 
247 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
248 {
249 	return container_of(card, struct fw_ohci, card);
250 }
251 
252 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
253 #define IR_CONTEXT_BUFFER_FILL		0x80000000
254 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
255 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
256 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
257 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
258 
259 #define CONTEXT_RUN	0x8000
260 #define CONTEXT_WAKE	0x1000
261 #define CONTEXT_DEAD	0x0800
262 #define CONTEXT_ACTIVE	0x0400
263 
264 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
265 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
266 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
267 
268 #define OHCI1394_REGISTER_SIZE		0x800
269 #define OHCI1394_PCI_HCI_Control	0x40
270 #define SELF_ID_BUF_SIZE		0x800
271 #define OHCI_TCODE_PHY_PACKET		0x0e
272 #define OHCI_VERSION_1_1		0x010010
273 
274 static char ohci_driver_name[] = KBUILD_MODNAME;
275 
276 #define PCI_VENDOR_ID_PINNACLE_SYSTEMS	0x11bd
277 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
278 #define PCI_DEVICE_ID_CREATIVE_SB1394	0x4001
279 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
280 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
281 #define PCI_DEVICE_ID_TI_TSB12LV26	0x8020
282 #define PCI_DEVICE_ID_TI_TSB82AA2	0x8025
283 #define PCI_DEVICE_ID_VIA_VT630X	0x3044
284 #define PCI_REV_ID_VIA_VT6306		0x46
285 #define PCI_DEVICE_ID_VIA_VT6315	0x3403
286 
287 #define QUIRK_CYCLE_TIMER		0x1
288 #define QUIRK_RESET_PACKET		0x2
289 #define QUIRK_BE_HEADERS		0x4
290 #define QUIRK_NO_1394A			0x8
291 #define QUIRK_NO_MSI			0x10
292 #define QUIRK_TI_SLLZ059		0x20
293 #define QUIRK_IR_WAKE			0x40
294 
295 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
296 static const struct {
297 	unsigned short vendor, device, revision, flags;
298 } ohci_quirks[] = {
299 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
300 		QUIRK_CYCLE_TIMER},
301 
302 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
303 		QUIRK_BE_HEADERS},
304 
305 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
306 		QUIRK_NO_MSI},
307 
308 	{PCI_VENDOR_ID_CREATIVE, PCI_DEVICE_ID_CREATIVE_SB1394, PCI_ANY_ID,
309 		QUIRK_RESET_PACKET},
310 
311 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
312 		QUIRK_NO_MSI},
313 
314 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
315 		QUIRK_CYCLE_TIMER},
316 
317 	{PCI_VENDOR_ID_O2, PCI_ANY_ID, PCI_ANY_ID,
318 		QUIRK_NO_MSI},
319 
320 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
321 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
322 
323 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
324 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
325 
326 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV26, PCI_ANY_ID,
327 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
328 
329 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB82AA2, PCI_ANY_ID,
330 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
331 
332 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
333 		QUIRK_RESET_PACKET},
334 
335 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT630X, PCI_REV_ID_VIA_VT6306,
336 		QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE},
337 
338 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, 0,
339 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
340 
341 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, PCI_ANY_ID,
342 		0},
343 
344 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
345 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
346 };
347 
348 /* This overrides anything that was found in ohci_quirks[]. */
349 static int param_quirks;
350 module_param_named(quirks, param_quirks, int, 0644);
351 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
352 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
353 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
354 	", AR/selfID endianness = "	__stringify(QUIRK_BE_HEADERS)
355 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
356 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
357 	", TI SLLZ059 erratum = "	__stringify(QUIRK_TI_SLLZ059)
358 	", IR wake unreliable = "	__stringify(QUIRK_IR_WAKE)
359 	")");
360 
361 #define OHCI_PARAM_DEBUG_AT_AR		1
362 #define OHCI_PARAM_DEBUG_SELFIDS	2
363 #define OHCI_PARAM_DEBUG_IRQS		4
364 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
365 
366 static int param_debug;
367 module_param_named(debug, param_debug, int, 0644);
368 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
369 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
370 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
371 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
372 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
373 	", or a combination, or all = -1)");
374 
375 static bool param_remote_dma;
376 module_param_named(remote_dma, param_remote_dma, bool, 0444);
377 MODULE_PARM_DESC(remote_dma, "Enable unfiltered remote DMA (default = N)");
378 
379 static void log_irqs(struct fw_ohci *ohci, u32 evt)
380 {
381 	if (likely(!(param_debug &
382 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
383 		return;
384 
385 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
386 	    !(evt & OHCI1394_busReset))
387 		return;
388 
389 	ohci_notice(ohci, "IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
390 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
391 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
392 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
393 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
394 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
395 	    evt & OHCI1394_isochRx		? " IR"			: "",
396 	    evt & OHCI1394_isochTx		? " IT"			: "",
397 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
398 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
399 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
400 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
401 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
402 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
403 	    evt & OHCI1394_busReset		? " busReset"		: "",
404 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
405 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
406 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
407 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
408 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
409 		    OHCI1394_cycleInconsistent |
410 		    OHCI1394_regAccessFail | OHCI1394_busReset)
411 						? " ?"			: "");
412 }
413 
414 static const char *speed[] = {
415 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
416 };
417 static const char *power[] = {
418 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
419 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
420 };
421 static const char port[] = { '.', '-', 'p', 'c', };
422 
423 static char _p(u32 *s, int shift)
424 {
425 	return port[*s >> shift & 3];
426 }
427 
428 static void log_selfids(struct fw_ohci *ohci, int generation, int self_id_count)
429 {
430 	u32 *s;
431 
432 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
433 		return;
434 
435 	ohci_notice(ohci, "%d selfIDs, generation %d, local node ID %04x\n",
436 		    self_id_count, generation, ohci->node_id);
437 
438 	for (s = ohci->self_id_buffer; self_id_count--; ++s)
439 		if ((*s & 1 << 23) == 0)
440 			ohci_notice(ohci,
441 			    "selfID 0: %08x, phy %d [%c%c%c] %s gc=%d %s %s%s%s\n",
442 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
443 			    speed[*s >> 14 & 3], *s >> 16 & 63,
444 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
445 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
446 		else
447 			ohci_notice(ohci,
448 			    "selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
449 			    *s, *s >> 24 & 63,
450 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
451 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
452 }
453 
454 static const char *evts[] = {
455 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
456 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
457 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
458 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
459 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
460 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
461 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
462 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
463 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
464 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
465 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
466 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
467 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
468 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
469 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
470 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
471 	[0x20] = "pending/cancelled",
472 };
473 static const char *tcodes[] = {
474 	[0x0] = "QW req",		[0x1] = "BW req",
475 	[0x2] = "W resp",		[0x3] = "-reserved-",
476 	[0x4] = "QR req",		[0x5] = "BR req",
477 	[0x6] = "QR resp",		[0x7] = "BR resp",
478 	[0x8] = "cycle start",		[0x9] = "Lk req",
479 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
480 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
481 	[0xe] = "link internal",	[0xf] = "-reserved-",
482 };
483 
484 static void log_ar_at_event(struct fw_ohci *ohci,
485 			    char dir, int speed, u32 *header, int evt)
486 {
487 	int tcode = header[0] >> 4 & 0xf;
488 	char specific[12];
489 
490 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
491 		return;
492 
493 	if (unlikely(evt >= ARRAY_SIZE(evts)))
494 			evt = 0x1f;
495 
496 	if (evt == OHCI1394_evt_bus_reset) {
497 		ohci_notice(ohci, "A%c evt_bus_reset, generation %d\n",
498 			    dir, (header[2] >> 16) & 0xff);
499 		return;
500 	}
501 
502 	switch (tcode) {
503 	case 0x0: case 0x6: case 0x8:
504 		snprintf(specific, sizeof(specific), " = %08x",
505 			 be32_to_cpu((__force __be32)header[3]));
506 		break;
507 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
508 		snprintf(specific, sizeof(specific), " %x,%x",
509 			 header[3] >> 16, header[3] & 0xffff);
510 		break;
511 	default:
512 		specific[0] = '\0';
513 	}
514 
515 	switch (tcode) {
516 	case 0xa:
517 		ohci_notice(ohci, "A%c %s, %s\n",
518 			    dir, evts[evt], tcodes[tcode]);
519 		break;
520 	case 0xe:
521 		ohci_notice(ohci, "A%c %s, PHY %08x %08x\n",
522 			    dir, evts[evt], header[1], header[2]);
523 		break;
524 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
525 		ohci_notice(ohci,
526 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s, %04x%08x%s\n",
527 			    dir, speed, header[0] >> 10 & 0x3f,
528 			    header[1] >> 16, header[0] >> 16, evts[evt],
529 			    tcodes[tcode], header[1] & 0xffff, header[2], specific);
530 		break;
531 	default:
532 		ohci_notice(ohci,
533 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s%s\n",
534 			    dir, speed, header[0] >> 10 & 0x3f,
535 			    header[1] >> 16, header[0] >> 16, evts[evt],
536 			    tcodes[tcode], specific);
537 	}
538 }
539 
540 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
541 {
542 	writel(data, ohci->registers + offset);
543 }
544 
545 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
546 {
547 	return readl(ohci->registers + offset);
548 }
549 
550 static inline void flush_writes(const struct fw_ohci *ohci)
551 {
552 	/* Do a dummy read to flush writes. */
553 	reg_read(ohci, OHCI1394_Version);
554 }
555 
556 /*
557  * Beware!  read_phy_reg(), write_phy_reg(), update_phy_reg(), and
558  * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
559  * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
560  * directly.  Exceptions are intrinsically serialized contexts like pci_probe.
561  */
562 static int read_phy_reg(struct fw_ohci *ohci, int addr)
563 {
564 	u32 val;
565 	int i;
566 
567 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
568 	for (i = 0; i < 3 + 100; i++) {
569 		val = reg_read(ohci, OHCI1394_PhyControl);
570 		if (!~val)
571 			return -ENODEV; /* Card was ejected. */
572 
573 		if (val & OHCI1394_PhyControl_ReadDone)
574 			return OHCI1394_PhyControl_ReadData(val);
575 
576 		/*
577 		 * Try a few times without waiting.  Sleeping is necessary
578 		 * only when the link/PHY interface is busy.
579 		 */
580 		if (i >= 3)
581 			msleep(1);
582 	}
583 	ohci_err(ohci, "failed to read phy reg %d\n", addr);
584 	dump_stack();
585 
586 	return -EBUSY;
587 }
588 
589 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
590 {
591 	int i;
592 
593 	reg_write(ohci, OHCI1394_PhyControl,
594 		  OHCI1394_PhyControl_Write(addr, val));
595 	for (i = 0; i < 3 + 100; i++) {
596 		val = reg_read(ohci, OHCI1394_PhyControl);
597 		if (!~val)
598 			return -ENODEV; /* Card was ejected. */
599 
600 		if (!(val & OHCI1394_PhyControl_WritePending))
601 			return 0;
602 
603 		if (i >= 3)
604 			msleep(1);
605 	}
606 	ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
607 	dump_stack();
608 
609 	return -EBUSY;
610 }
611 
612 static int update_phy_reg(struct fw_ohci *ohci, int addr,
613 			  int clear_bits, int set_bits)
614 {
615 	int ret = read_phy_reg(ohci, addr);
616 	if (ret < 0)
617 		return ret;
618 
619 	/*
620 	 * The interrupt status bits are cleared by writing a one bit.
621 	 * Avoid clearing them unless explicitly requested in set_bits.
622 	 */
623 	if (addr == 5)
624 		clear_bits |= PHY_INT_STATUS_BITS;
625 
626 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
627 }
628 
629 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
630 {
631 	int ret;
632 
633 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
634 	if (ret < 0)
635 		return ret;
636 
637 	return read_phy_reg(ohci, addr);
638 }
639 
640 static int ohci_read_phy_reg(struct fw_card *card, int addr)
641 {
642 	struct fw_ohci *ohci = fw_ohci(card);
643 	int ret;
644 
645 	mutex_lock(&ohci->phy_reg_mutex);
646 	ret = read_phy_reg(ohci, addr);
647 	mutex_unlock(&ohci->phy_reg_mutex);
648 
649 	return ret;
650 }
651 
652 static int ohci_update_phy_reg(struct fw_card *card, int addr,
653 			       int clear_bits, int set_bits)
654 {
655 	struct fw_ohci *ohci = fw_ohci(card);
656 	int ret;
657 
658 	mutex_lock(&ohci->phy_reg_mutex);
659 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
660 	mutex_unlock(&ohci->phy_reg_mutex);
661 
662 	return ret;
663 }
664 
665 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
666 {
667 	return page_private(ctx->pages[i]);
668 }
669 
670 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
671 {
672 	struct descriptor *d;
673 
674 	d = &ctx->descriptors[index];
675 	d->branch_address  &= cpu_to_le32(~0xf);
676 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
677 	d->transfer_status =  0;
678 
679 	wmb(); /* finish init of new descriptors before branch_address update */
680 	d = &ctx->descriptors[ctx->last_buffer_index];
681 	d->branch_address  |= cpu_to_le32(1);
682 
683 	ctx->last_buffer_index = index;
684 
685 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
686 }
687 
688 static void ar_context_release(struct ar_context *ctx)
689 {
690 	unsigned int i;
691 
692 	if (ctx->buffer)
693 		vm_unmap_ram(ctx->buffer, AR_BUFFERS + AR_WRAPAROUND_PAGES);
694 
695 	for (i = 0; i < AR_BUFFERS; i++)
696 		if (ctx->pages[i]) {
697 			dma_unmap_page(ctx->ohci->card.device,
698 				       ar_buffer_bus(ctx, i),
699 				       PAGE_SIZE, DMA_FROM_DEVICE);
700 			__free_page(ctx->pages[i]);
701 		}
702 }
703 
704 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
705 {
706 	struct fw_ohci *ohci = ctx->ohci;
707 
708 	if (reg_read(ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
709 		reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
710 		flush_writes(ohci);
711 
712 		ohci_err(ohci, "AR error: %s; DMA stopped\n", error_msg);
713 	}
714 	/* FIXME: restart? */
715 }
716 
717 static inline unsigned int ar_next_buffer_index(unsigned int index)
718 {
719 	return (index + 1) % AR_BUFFERS;
720 }
721 
722 static inline unsigned int ar_prev_buffer_index(unsigned int index)
723 {
724 	return (index - 1 + AR_BUFFERS) % AR_BUFFERS;
725 }
726 
727 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
728 {
729 	return ar_next_buffer_index(ctx->last_buffer_index);
730 }
731 
732 /*
733  * We search for the buffer that contains the last AR packet DMA data written
734  * by the controller.
735  */
736 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
737 						 unsigned int *buffer_offset)
738 {
739 	unsigned int i, next_i, last = ctx->last_buffer_index;
740 	__le16 res_count, next_res_count;
741 
742 	i = ar_first_buffer_index(ctx);
743 	res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
744 
745 	/* A buffer that is not yet completely filled must be the last one. */
746 	while (i != last && res_count == 0) {
747 
748 		/* Peek at the next descriptor. */
749 		next_i = ar_next_buffer_index(i);
750 		rmb(); /* read descriptors in order */
751 		next_res_count = ACCESS_ONCE(
752 				ctx->descriptors[next_i].res_count);
753 		/*
754 		 * If the next descriptor is still empty, we must stop at this
755 		 * descriptor.
756 		 */
757 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
758 			/*
759 			 * The exception is when the DMA data for one packet is
760 			 * split over three buffers; in this case, the middle
761 			 * buffer's descriptor might be never updated by the
762 			 * controller and look still empty, and we have to peek
763 			 * at the third one.
764 			 */
765 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
766 				next_i = ar_next_buffer_index(next_i);
767 				rmb();
768 				next_res_count = ACCESS_ONCE(
769 					ctx->descriptors[next_i].res_count);
770 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
771 					goto next_buffer_is_active;
772 			}
773 
774 			break;
775 		}
776 
777 next_buffer_is_active:
778 		i = next_i;
779 		res_count = next_res_count;
780 	}
781 
782 	rmb(); /* read res_count before the DMA data */
783 
784 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
785 	if (*buffer_offset > PAGE_SIZE) {
786 		*buffer_offset = 0;
787 		ar_context_abort(ctx, "corrupted descriptor");
788 	}
789 
790 	return i;
791 }
792 
793 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
794 				    unsigned int end_buffer_index,
795 				    unsigned int end_buffer_offset)
796 {
797 	unsigned int i;
798 
799 	i = ar_first_buffer_index(ctx);
800 	while (i != end_buffer_index) {
801 		dma_sync_single_for_cpu(ctx->ohci->card.device,
802 					ar_buffer_bus(ctx, i),
803 					PAGE_SIZE, DMA_FROM_DEVICE);
804 		i = ar_next_buffer_index(i);
805 	}
806 	if (end_buffer_offset > 0)
807 		dma_sync_single_for_cpu(ctx->ohci->card.device,
808 					ar_buffer_bus(ctx, i),
809 					end_buffer_offset, DMA_FROM_DEVICE);
810 }
811 
812 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
813 #define cond_le32_to_cpu(v) \
814 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
815 #else
816 #define cond_le32_to_cpu(v) le32_to_cpu(v)
817 #endif
818 
819 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
820 {
821 	struct fw_ohci *ohci = ctx->ohci;
822 	struct fw_packet p;
823 	u32 status, length, tcode;
824 	int evt;
825 
826 	p.header[0] = cond_le32_to_cpu(buffer[0]);
827 	p.header[1] = cond_le32_to_cpu(buffer[1]);
828 	p.header[2] = cond_le32_to_cpu(buffer[2]);
829 
830 	tcode = (p.header[0] >> 4) & 0x0f;
831 	switch (tcode) {
832 	case TCODE_WRITE_QUADLET_REQUEST:
833 	case TCODE_READ_QUADLET_RESPONSE:
834 		p.header[3] = (__force __u32) buffer[3];
835 		p.header_length = 16;
836 		p.payload_length = 0;
837 		break;
838 
839 	case TCODE_READ_BLOCK_REQUEST :
840 		p.header[3] = cond_le32_to_cpu(buffer[3]);
841 		p.header_length = 16;
842 		p.payload_length = 0;
843 		break;
844 
845 	case TCODE_WRITE_BLOCK_REQUEST:
846 	case TCODE_READ_BLOCK_RESPONSE:
847 	case TCODE_LOCK_REQUEST:
848 	case TCODE_LOCK_RESPONSE:
849 		p.header[3] = cond_le32_to_cpu(buffer[3]);
850 		p.header_length = 16;
851 		p.payload_length = p.header[3] >> 16;
852 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
853 			ar_context_abort(ctx, "invalid packet length");
854 			return NULL;
855 		}
856 		break;
857 
858 	case TCODE_WRITE_RESPONSE:
859 	case TCODE_READ_QUADLET_REQUEST:
860 	case OHCI_TCODE_PHY_PACKET:
861 		p.header_length = 12;
862 		p.payload_length = 0;
863 		break;
864 
865 	default:
866 		ar_context_abort(ctx, "invalid tcode");
867 		return NULL;
868 	}
869 
870 	p.payload = (void *) buffer + p.header_length;
871 
872 	/* FIXME: What to do about evt_* errors? */
873 	length = (p.header_length + p.payload_length + 3) / 4;
874 	status = cond_le32_to_cpu(buffer[length]);
875 	evt    = (status >> 16) & 0x1f;
876 
877 	p.ack        = evt - 16;
878 	p.speed      = (status >> 21) & 0x7;
879 	p.timestamp  = status & 0xffff;
880 	p.generation = ohci->request_generation;
881 
882 	log_ar_at_event(ohci, 'R', p.speed, p.header, evt);
883 
884 	/*
885 	 * Several controllers, notably from NEC and VIA, forget to
886 	 * write ack_complete status at PHY packet reception.
887 	 */
888 	if (evt == OHCI1394_evt_no_status &&
889 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
890 		p.ack = ACK_COMPLETE;
891 
892 	/*
893 	 * The OHCI bus reset handler synthesizes a PHY packet with
894 	 * the new generation number when a bus reset happens (see
895 	 * section 8.4.2.3).  This helps us determine when a request
896 	 * was received and make sure we send the response in the same
897 	 * generation.  We only need this for requests; for responses
898 	 * we use the unique tlabel for finding the matching
899 	 * request.
900 	 *
901 	 * Alas some chips sometimes emit bus reset packets with a
902 	 * wrong generation.  We set the correct generation for these
903 	 * at a slightly incorrect time (in bus_reset_work).
904 	 */
905 	if (evt == OHCI1394_evt_bus_reset) {
906 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
907 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
908 	} else if (ctx == &ohci->ar_request_ctx) {
909 		fw_core_handle_request(&ohci->card, &p);
910 	} else {
911 		fw_core_handle_response(&ohci->card, &p);
912 	}
913 
914 	return buffer + length + 1;
915 }
916 
917 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
918 {
919 	void *next;
920 
921 	while (p < end) {
922 		next = handle_ar_packet(ctx, p);
923 		if (!next)
924 			return p;
925 		p = next;
926 	}
927 
928 	return p;
929 }
930 
931 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
932 {
933 	unsigned int i;
934 
935 	i = ar_first_buffer_index(ctx);
936 	while (i != end_buffer) {
937 		dma_sync_single_for_device(ctx->ohci->card.device,
938 					   ar_buffer_bus(ctx, i),
939 					   PAGE_SIZE, DMA_FROM_DEVICE);
940 		ar_context_link_page(ctx, i);
941 		i = ar_next_buffer_index(i);
942 	}
943 }
944 
945 static void ar_context_tasklet(unsigned long data)
946 {
947 	struct ar_context *ctx = (struct ar_context *)data;
948 	unsigned int end_buffer_index, end_buffer_offset;
949 	void *p, *end;
950 
951 	p = ctx->pointer;
952 	if (!p)
953 		return;
954 
955 	end_buffer_index = ar_search_last_active_buffer(ctx,
956 							&end_buffer_offset);
957 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
958 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
959 
960 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
961 		/*
962 		 * The filled part of the overall buffer wraps around; handle
963 		 * all packets up to the buffer end here.  If the last packet
964 		 * wraps around, its tail will be visible after the buffer end
965 		 * because the buffer start pages are mapped there again.
966 		 */
967 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
968 		p = handle_ar_packets(ctx, p, buffer_end);
969 		if (p < buffer_end)
970 			goto error;
971 		/* adjust p to point back into the actual buffer */
972 		p -= AR_BUFFERS * PAGE_SIZE;
973 	}
974 
975 	p = handle_ar_packets(ctx, p, end);
976 	if (p != end) {
977 		if (p > end)
978 			ar_context_abort(ctx, "inconsistent descriptor");
979 		goto error;
980 	}
981 
982 	ctx->pointer = p;
983 	ar_recycle_buffers(ctx, end_buffer_index);
984 
985 	return;
986 
987 error:
988 	ctx->pointer = NULL;
989 }
990 
991 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
992 			   unsigned int descriptors_offset, u32 regs)
993 {
994 	unsigned int i;
995 	dma_addr_t dma_addr;
996 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
997 	struct descriptor *d;
998 
999 	ctx->regs        = regs;
1000 	ctx->ohci        = ohci;
1001 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
1002 
1003 	for (i = 0; i < AR_BUFFERS; i++) {
1004 		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
1005 		if (!ctx->pages[i])
1006 			goto out_of_memory;
1007 		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
1008 					0, PAGE_SIZE, DMA_FROM_DEVICE);
1009 		if (dma_mapping_error(ohci->card.device, dma_addr)) {
1010 			__free_page(ctx->pages[i]);
1011 			ctx->pages[i] = NULL;
1012 			goto out_of_memory;
1013 		}
1014 		set_page_private(ctx->pages[i], dma_addr);
1015 	}
1016 
1017 	for (i = 0; i < AR_BUFFERS; i++)
1018 		pages[i]              = ctx->pages[i];
1019 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
1020 		pages[AR_BUFFERS + i] = ctx->pages[i];
1021 	ctx->buffer = vm_map_ram(pages, AR_BUFFERS + AR_WRAPAROUND_PAGES,
1022 				 -1, PAGE_KERNEL);
1023 	if (!ctx->buffer)
1024 		goto out_of_memory;
1025 
1026 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
1027 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
1028 
1029 	for (i = 0; i < AR_BUFFERS; i++) {
1030 		d = &ctx->descriptors[i];
1031 		d->req_count      = cpu_to_le16(PAGE_SIZE);
1032 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
1033 						DESCRIPTOR_STATUS |
1034 						DESCRIPTOR_BRANCH_ALWAYS);
1035 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
1036 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
1037 			ar_next_buffer_index(i) * sizeof(struct descriptor));
1038 	}
1039 
1040 	return 0;
1041 
1042 out_of_memory:
1043 	ar_context_release(ctx);
1044 
1045 	return -ENOMEM;
1046 }
1047 
1048 static void ar_context_run(struct ar_context *ctx)
1049 {
1050 	unsigned int i;
1051 
1052 	for (i = 0; i < AR_BUFFERS; i++)
1053 		ar_context_link_page(ctx, i);
1054 
1055 	ctx->pointer = ctx->buffer;
1056 
1057 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1058 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1059 }
1060 
1061 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1062 {
1063 	__le16 branch;
1064 
1065 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1066 
1067 	/* figure out which descriptor the branch address goes in */
1068 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1069 		return d;
1070 	else
1071 		return d + z - 1;
1072 }
1073 
1074 static void context_tasklet(unsigned long data)
1075 {
1076 	struct context *ctx = (struct context *) data;
1077 	struct descriptor *d, *last;
1078 	u32 address;
1079 	int z;
1080 	struct descriptor_buffer *desc;
1081 
1082 	desc = list_entry(ctx->buffer_list.next,
1083 			struct descriptor_buffer, list);
1084 	last = ctx->last;
1085 	while (last->branch_address != 0) {
1086 		struct descriptor_buffer *old_desc = desc;
1087 		address = le32_to_cpu(last->branch_address);
1088 		z = address & 0xf;
1089 		address &= ~0xf;
1090 		ctx->current_bus = address;
1091 
1092 		/* If the branch address points to a buffer outside of the
1093 		 * current buffer, advance to the next buffer. */
1094 		if (address < desc->buffer_bus ||
1095 				address >= desc->buffer_bus + desc->used)
1096 			desc = list_entry(desc->list.next,
1097 					struct descriptor_buffer, list);
1098 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1099 		last = find_branch_descriptor(d, z);
1100 
1101 		if (!ctx->callback(ctx, d, last))
1102 			break;
1103 
1104 		if (old_desc != desc) {
1105 			/* If we've advanced to the next buffer, move the
1106 			 * previous buffer to the free list. */
1107 			unsigned long flags;
1108 			old_desc->used = 0;
1109 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1110 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1111 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1112 		}
1113 		ctx->last = last;
1114 	}
1115 }
1116 
1117 /*
1118  * Allocate a new buffer and add it to the list of free buffers for this
1119  * context.  Must be called with ohci->lock held.
1120  */
1121 static int context_add_buffer(struct context *ctx)
1122 {
1123 	struct descriptor_buffer *desc;
1124 	dma_addr_t uninitialized_var(bus_addr);
1125 	int offset;
1126 
1127 	/*
1128 	 * 16MB of descriptors should be far more than enough for any DMA
1129 	 * program.  This will catch run-away userspace or DoS attacks.
1130 	 */
1131 	if (ctx->total_allocation >= 16*1024*1024)
1132 		return -ENOMEM;
1133 
1134 	desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1135 			&bus_addr, GFP_ATOMIC);
1136 	if (!desc)
1137 		return -ENOMEM;
1138 
1139 	offset = (void *)&desc->buffer - (void *)desc;
1140 	desc->buffer_size = PAGE_SIZE - offset;
1141 	desc->buffer_bus = bus_addr + offset;
1142 	desc->used = 0;
1143 
1144 	list_add_tail(&desc->list, &ctx->buffer_list);
1145 	ctx->total_allocation += PAGE_SIZE;
1146 
1147 	return 0;
1148 }
1149 
1150 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1151 			u32 regs, descriptor_callback_t callback)
1152 {
1153 	ctx->ohci = ohci;
1154 	ctx->regs = regs;
1155 	ctx->total_allocation = 0;
1156 
1157 	INIT_LIST_HEAD(&ctx->buffer_list);
1158 	if (context_add_buffer(ctx) < 0)
1159 		return -ENOMEM;
1160 
1161 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1162 			struct descriptor_buffer, list);
1163 
1164 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1165 	ctx->callback = callback;
1166 
1167 	/*
1168 	 * We put a dummy descriptor in the buffer that has a NULL
1169 	 * branch address and looks like it's been sent.  That way we
1170 	 * have a descriptor to append DMA programs to.
1171 	 */
1172 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1173 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1174 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1175 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1176 	ctx->last = ctx->buffer_tail->buffer;
1177 	ctx->prev = ctx->buffer_tail->buffer;
1178 	ctx->prev_z = 1;
1179 
1180 	return 0;
1181 }
1182 
1183 static void context_release(struct context *ctx)
1184 {
1185 	struct fw_card *card = &ctx->ohci->card;
1186 	struct descriptor_buffer *desc, *tmp;
1187 
1188 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1189 		dma_free_coherent(card->device, PAGE_SIZE, desc,
1190 			desc->buffer_bus -
1191 			((void *)&desc->buffer - (void *)desc));
1192 }
1193 
1194 /* Must be called with ohci->lock held */
1195 static struct descriptor *context_get_descriptors(struct context *ctx,
1196 						  int z, dma_addr_t *d_bus)
1197 {
1198 	struct descriptor *d = NULL;
1199 	struct descriptor_buffer *desc = ctx->buffer_tail;
1200 
1201 	if (z * sizeof(*d) > desc->buffer_size)
1202 		return NULL;
1203 
1204 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1205 		/* No room for the descriptor in this buffer, so advance to the
1206 		 * next one. */
1207 
1208 		if (desc->list.next == &ctx->buffer_list) {
1209 			/* If there is no free buffer next in the list,
1210 			 * allocate one. */
1211 			if (context_add_buffer(ctx) < 0)
1212 				return NULL;
1213 		}
1214 		desc = list_entry(desc->list.next,
1215 				struct descriptor_buffer, list);
1216 		ctx->buffer_tail = desc;
1217 	}
1218 
1219 	d = desc->buffer + desc->used / sizeof(*d);
1220 	memset(d, 0, z * sizeof(*d));
1221 	*d_bus = desc->buffer_bus + desc->used;
1222 
1223 	return d;
1224 }
1225 
1226 static void context_run(struct context *ctx, u32 extra)
1227 {
1228 	struct fw_ohci *ohci = ctx->ohci;
1229 
1230 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1231 		  le32_to_cpu(ctx->last->branch_address));
1232 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1233 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1234 	ctx->running = true;
1235 	flush_writes(ohci);
1236 }
1237 
1238 static void context_append(struct context *ctx,
1239 			   struct descriptor *d, int z, int extra)
1240 {
1241 	dma_addr_t d_bus;
1242 	struct descriptor_buffer *desc = ctx->buffer_tail;
1243 	struct descriptor *d_branch;
1244 
1245 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1246 
1247 	desc->used += (z + extra) * sizeof(*d);
1248 
1249 	wmb(); /* finish init of new descriptors before branch_address update */
1250 
1251 	d_branch = find_branch_descriptor(ctx->prev, ctx->prev_z);
1252 	d_branch->branch_address = cpu_to_le32(d_bus | z);
1253 
1254 	/*
1255 	 * VT6306 incorrectly checks only the single descriptor at the
1256 	 * CommandPtr when the wake bit is written, so if it's a
1257 	 * multi-descriptor block starting with an INPUT_MORE, put a copy of
1258 	 * the branch address in the first descriptor.
1259 	 *
1260 	 * Not doing this for transmit contexts since not sure how it interacts
1261 	 * with skip addresses.
1262 	 */
1263 	if (unlikely(ctx->ohci->quirks & QUIRK_IR_WAKE) &&
1264 	    d_branch != ctx->prev &&
1265 	    (ctx->prev->control & cpu_to_le16(DESCRIPTOR_CMD)) ==
1266 	     cpu_to_le16(DESCRIPTOR_INPUT_MORE)) {
1267 		ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1268 	}
1269 
1270 	ctx->prev = d;
1271 	ctx->prev_z = z;
1272 }
1273 
1274 static void context_stop(struct context *ctx)
1275 {
1276 	struct fw_ohci *ohci = ctx->ohci;
1277 	u32 reg;
1278 	int i;
1279 
1280 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1281 	ctx->running = false;
1282 
1283 	for (i = 0; i < 1000; i++) {
1284 		reg = reg_read(ohci, CONTROL_SET(ctx->regs));
1285 		if ((reg & CONTEXT_ACTIVE) == 0)
1286 			return;
1287 
1288 		if (i)
1289 			udelay(10);
1290 	}
1291 	ohci_err(ohci, "DMA context still active (0x%08x)\n", reg);
1292 }
1293 
1294 struct driver_data {
1295 	u8 inline_data[8];
1296 	struct fw_packet *packet;
1297 };
1298 
1299 /*
1300  * This function apppends a packet to the DMA queue for transmission.
1301  * Must always be called with the ochi->lock held to ensure proper
1302  * generation handling and locking around packet queue manipulation.
1303  */
1304 static int at_context_queue_packet(struct context *ctx,
1305 				   struct fw_packet *packet)
1306 {
1307 	struct fw_ohci *ohci = ctx->ohci;
1308 	dma_addr_t d_bus, uninitialized_var(payload_bus);
1309 	struct driver_data *driver_data;
1310 	struct descriptor *d, *last;
1311 	__le32 *header;
1312 	int z, tcode;
1313 
1314 	d = context_get_descriptors(ctx, 4, &d_bus);
1315 	if (d == NULL) {
1316 		packet->ack = RCODE_SEND_ERROR;
1317 		return -1;
1318 	}
1319 
1320 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1321 	d[0].res_count = cpu_to_le16(packet->timestamp);
1322 
1323 	/*
1324 	 * The DMA format for asynchronous link packets is different
1325 	 * from the IEEE1394 layout, so shift the fields around
1326 	 * accordingly.
1327 	 */
1328 
1329 	tcode = (packet->header[0] >> 4) & 0x0f;
1330 	header = (__le32 *) &d[1];
1331 	switch (tcode) {
1332 	case TCODE_WRITE_QUADLET_REQUEST:
1333 	case TCODE_WRITE_BLOCK_REQUEST:
1334 	case TCODE_WRITE_RESPONSE:
1335 	case TCODE_READ_QUADLET_REQUEST:
1336 	case TCODE_READ_BLOCK_REQUEST:
1337 	case TCODE_READ_QUADLET_RESPONSE:
1338 	case TCODE_READ_BLOCK_RESPONSE:
1339 	case TCODE_LOCK_REQUEST:
1340 	case TCODE_LOCK_RESPONSE:
1341 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1342 					(packet->speed << 16));
1343 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1344 					(packet->header[0] & 0xffff0000));
1345 		header[2] = cpu_to_le32(packet->header[2]);
1346 
1347 		if (TCODE_IS_BLOCK_PACKET(tcode))
1348 			header[3] = cpu_to_le32(packet->header[3]);
1349 		else
1350 			header[3] = (__force __le32) packet->header[3];
1351 
1352 		d[0].req_count = cpu_to_le16(packet->header_length);
1353 		break;
1354 
1355 	case TCODE_LINK_INTERNAL:
1356 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1357 					(packet->speed << 16));
1358 		header[1] = cpu_to_le32(packet->header[1]);
1359 		header[2] = cpu_to_le32(packet->header[2]);
1360 		d[0].req_count = cpu_to_le16(12);
1361 
1362 		if (is_ping_packet(&packet->header[1]))
1363 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1364 		break;
1365 
1366 	case TCODE_STREAM_DATA:
1367 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1368 					(packet->speed << 16));
1369 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1370 		d[0].req_count = cpu_to_le16(8);
1371 		break;
1372 
1373 	default:
1374 		/* BUG(); */
1375 		packet->ack = RCODE_SEND_ERROR;
1376 		return -1;
1377 	}
1378 
1379 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1380 	driver_data = (struct driver_data *) &d[3];
1381 	driver_data->packet = packet;
1382 	packet->driver_data = driver_data;
1383 
1384 	if (packet->payload_length > 0) {
1385 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1386 			payload_bus = dma_map_single(ohci->card.device,
1387 						     packet->payload,
1388 						     packet->payload_length,
1389 						     DMA_TO_DEVICE);
1390 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1391 				packet->ack = RCODE_SEND_ERROR;
1392 				return -1;
1393 			}
1394 			packet->payload_bus	= payload_bus;
1395 			packet->payload_mapped	= true;
1396 		} else {
1397 			memcpy(driver_data->inline_data, packet->payload,
1398 			       packet->payload_length);
1399 			payload_bus = d_bus + 3 * sizeof(*d);
1400 		}
1401 
1402 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1403 		d[2].data_address = cpu_to_le32(payload_bus);
1404 		last = &d[2];
1405 		z = 3;
1406 	} else {
1407 		last = &d[0];
1408 		z = 2;
1409 	}
1410 
1411 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1412 				     DESCRIPTOR_IRQ_ALWAYS |
1413 				     DESCRIPTOR_BRANCH_ALWAYS);
1414 
1415 	/* FIXME: Document how the locking works. */
1416 	if (ohci->generation != packet->generation) {
1417 		if (packet->payload_mapped)
1418 			dma_unmap_single(ohci->card.device, payload_bus,
1419 					 packet->payload_length, DMA_TO_DEVICE);
1420 		packet->ack = RCODE_GENERATION;
1421 		return -1;
1422 	}
1423 
1424 	context_append(ctx, d, z, 4 - z);
1425 
1426 	if (ctx->running)
1427 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1428 	else
1429 		context_run(ctx, 0);
1430 
1431 	return 0;
1432 }
1433 
1434 static void at_context_flush(struct context *ctx)
1435 {
1436 	tasklet_disable(&ctx->tasklet);
1437 
1438 	ctx->flushing = true;
1439 	context_tasklet((unsigned long)ctx);
1440 	ctx->flushing = false;
1441 
1442 	tasklet_enable(&ctx->tasklet);
1443 }
1444 
1445 static int handle_at_packet(struct context *context,
1446 			    struct descriptor *d,
1447 			    struct descriptor *last)
1448 {
1449 	struct driver_data *driver_data;
1450 	struct fw_packet *packet;
1451 	struct fw_ohci *ohci = context->ohci;
1452 	int evt;
1453 
1454 	if (last->transfer_status == 0 && !context->flushing)
1455 		/* This descriptor isn't done yet, stop iteration. */
1456 		return 0;
1457 
1458 	driver_data = (struct driver_data *) &d[3];
1459 	packet = driver_data->packet;
1460 	if (packet == NULL)
1461 		/* This packet was cancelled, just continue. */
1462 		return 1;
1463 
1464 	if (packet->payload_mapped)
1465 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1466 				 packet->payload_length, DMA_TO_DEVICE);
1467 
1468 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1469 	packet->timestamp = le16_to_cpu(last->res_count);
1470 
1471 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, evt);
1472 
1473 	switch (evt) {
1474 	case OHCI1394_evt_timeout:
1475 		/* Async response transmit timed out. */
1476 		packet->ack = RCODE_CANCELLED;
1477 		break;
1478 
1479 	case OHCI1394_evt_flushed:
1480 		/*
1481 		 * The packet was flushed should give same error as
1482 		 * when we try to use a stale generation count.
1483 		 */
1484 		packet->ack = RCODE_GENERATION;
1485 		break;
1486 
1487 	case OHCI1394_evt_missing_ack:
1488 		if (context->flushing)
1489 			packet->ack = RCODE_GENERATION;
1490 		else {
1491 			/*
1492 			 * Using a valid (current) generation count, but the
1493 			 * node is not on the bus or not sending acks.
1494 			 */
1495 			packet->ack = RCODE_NO_ACK;
1496 		}
1497 		break;
1498 
1499 	case ACK_COMPLETE + 0x10:
1500 	case ACK_PENDING + 0x10:
1501 	case ACK_BUSY_X + 0x10:
1502 	case ACK_BUSY_A + 0x10:
1503 	case ACK_BUSY_B + 0x10:
1504 	case ACK_DATA_ERROR + 0x10:
1505 	case ACK_TYPE_ERROR + 0x10:
1506 		packet->ack = evt - 0x10;
1507 		break;
1508 
1509 	case OHCI1394_evt_no_status:
1510 		if (context->flushing) {
1511 			packet->ack = RCODE_GENERATION;
1512 			break;
1513 		}
1514 		/* fall through */
1515 
1516 	default:
1517 		packet->ack = RCODE_SEND_ERROR;
1518 		break;
1519 	}
1520 
1521 	packet->callback(packet, &ohci->card, packet->ack);
1522 
1523 	return 1;
1524 }
1525 
1526 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1527 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1528 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1529 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1530 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
1531 
1532 static void handle_local_rom(struct fw_ohci *ohci,
1533 			     struct fw_packet *packet, u32 csr)
1534 {
1535 	struct fw_packet response;
1536 	int tcode, length, i;
1537 
1538 	tcode = HEADER_GET_TCODE(packet->header[0]);
1539 	if (TCODE_IS_BLOCK_PACKET(tcode))
1540 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1541 	else
1542 		length = 4;
1543 
1544 	i = csr - CSR_CONFIG_ROM;
1545 	if (i + length > CONFIG_ROM_SIZE) {
1546 		fw_fill_response(&response, packet->header,
1547 				 RCODE_ADDRESS_ERROR, NULL, 0);
1548 	} else if (!TCODE_IS_READ_REQUEST(tcode)) {
1549 		fw_fill_response(&response, packet->header,
1550 				 RCODE_TYPE_ERROR, NULL, 0);
1551 	} else {
1552 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1553 				 (void *) ohci->config_rom + i, length);
1554 	}
1555 
1556 	fw_core_handle_response(&ohci->card, &response);
1557 }
1558 
1559 static void handle_local_lock(struct fw_ohci *ohci,
1560 			      struct fw_packet *packet, u32 csr)
1561 {
1562 	struct fw_packet response;
1563 	int tcode, length, ext_tcode, sel, try;
1564 	__be32 *payload, lock_old;
1565 	u32 lock_arg, lock_data;
1566 
1567 	tcode = HEADER_GET_TCODE(packet->header[0]);
1568 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1569 	payload = packet->payload;
1570 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1571 
1572 	if (tcode == TCODE_LOCK_REQUEST &&
1573 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1574 		lock_arg = be32_to_cpu(payload[0]);
1575 		lock_data = be32_to_cpu(payload[1]);
1576 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1577 		lock_arg = 0;
1578 		lock_data = 0;
1579 	} else {
1580 		fw_fill_response(&response, packet->header,
1581 				 RCODE_TYPE_ERROR, NULL, 0);
1582 		goto out;
1583 	}
1584 
1585 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1586 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1587 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1588 	reg_write(ohci, OHCI1394_CSRControl, sel);
1589 
1590 	for (try = 0; try < 20; try++)
1591 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1592 			lock_old = cpu_to_be32(reg_read(ohci,
1593 							OHCI1394_CSRData));
1594 			fw_fill_response(&response, packet->header,
1595 					 RCODE_COMPLETE,
1596 					 &lock_old, sizeof(lock_old));
1597 			goto out;
1598 		}
1599 
1600 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
1601 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1602 
1603  out:
1604 	fw_core_handle_response(&ohci->card, &response);
1605 }
1606 
1607 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1608 {
1609 	u64 offset, csr;
1610 
1611 	if (ctx == &ctx->ohci->at_request_ctx) {
1612 		packet->ack = ACK_PENDING;
1613 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1614 	}
1615 
1616 	offset =
1617 		((unsigned long long)
1618 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1619 		packet->header[2];
1620 	csr = offset - CSR_REGISTER_BASE;
1621 
1622 	/* Handle config rom reads. */
1623 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1624 		handle_local_rom(ctx->ohci, packet, csr);
1625 	else switch (csr) {
1626 	case CSR_BUS_MANAGER_ID:
1627 	case CSR_BANDWIDTH_AVAILABLE:
1628 	case CSR_CHANNELS_AVAILABLE_HI:
1629 	case CSR_CHANNELS_AVAILABLE_LO:
1630 		handle_local_lock(ctx->ohci, packet, csr);
1631 		break;
1632 	default:
1633 		if (ctx == &ctx->ohci->at_request_ctx)
1634 			fw_core_handle_request(&ctx->ohci->card, packet);
1635 		else
1636 			fw_core_handle_response(&ctx->ohci->card, packet);
1637 		break;
1638 	}
1639 
1640 	if (ctx == &ctx->ohci->at_response_ctx) {
1641 		packet->ack = ACK_COMPLETE;
1642 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1643 	}
1644 }
1645 
1646 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1647 {
1648 	unsigned long flags;
1649 	int ret;
1650 
1651 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1652 
1653 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1654 	    ctx->ohci->generation == packet->generation) {
1655 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1656 		handle_local_request(ctx, packet);
1657 		return;
1658 	}
1659 
1660 	ret = at_context_queue_packet(ctx, packet);
1661 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1662 
1663 	if (ret < 0)
1664 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1665 
1666 }
1667 
1668 static void detect_dead_context(struct fw_ohci *ohci,
1669 				const char *name, unsigned int regs)
1670 {
1671 	u32 ctl;
1672 
1673 	ctl = reg_read(ohci, CONTROL_SET(regs));
1674 	if (ctl & CONTEXT_DEAD)
1675 		ohci_err(ohci, "DMA context %s has stopped, error code: %s\n",
1676 			name, evts[ctl & 0x1f]);
1677 }
1678 
1679 static void handle_dead_contexts(struct fw_ohci *ohci)
1680 {
1681 	unsigned int i;
1682 	char name[8];
1683 
1684 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1685 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1686 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1687 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1688 	for (i = 0; i < 32; ++i) {
1689 		if (!(ohci->it_context_support & (1 << i)))
1690 			continue;
1691 		sprintf(name, "IT%u", i);
1692 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1693 	}
1694 	for (i = 0; i < 32; ++i) {
1695 		if (!(ohci->ir_context_support & (1 << i)))
1696 			continue;
1697 		sprintf(name, "IR%u", i);
1698 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1699 	}
1700 	/* TODO: maybe try to flush and restart the dead contexts */
1701 }
1702 
1703 static u32 cycle_timer_ticks(u32 cycle_timer)
1704 {
1705 	u32 ticks;
1706 
1707 	ticks = cycle_timer & 0xfff;
1708 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1709 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1710 
1711 	return ticks;
1712 }
1713 
1714 /*
1715  * Some controllers exhibit one or more of the following bugs when updating the
1716  * iso cycle timer register:
1717  *  - When the lowest six bits are wrapping around to zero, a read that happens
1718  *    at the same time will return garbage in the lowest ten bits.
1719  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1720  *    not incremented for about 60 ns.
1721  *  - Occasionally, the entire register reads zero.
1722  *
1723  * To catch these, we read the register three times and ensure that the
1724  * difference between each two consecutive reads is approximately the same, i.e.
1725  * less than twice the other.  Furthermore, any negative difference indicates an
1726  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1727  * execute, so we have enough precision to compute the ratio of the differences.)
1728  */
1729 static u32 get_cycle_time(struct fw_ohci *ohci)
1730 {
1731 	u32 c0, c1, c2;
1732 	u32 t0, t1, t2;
1733 	s32 diff01, diff12;
1734 	int i;
1735 
1736 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1737 
1738 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1739 		i = 0;
1740 		c1 = c2;
1741 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1742 		do {
1743 			c0 = c1;
1744 			c1 = c2;
1745 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1746 			t0 = cycle_timer_ticks(c0);
1747 			t1 = cycle_timer_ticks(c1);
1748 			t2 = cycle_timer_ticks(c2);
1749 			diff01 = t1 - t0;
1750 			diff12 = t2 - t1;
1751 		} while ((diff01 <= 0 || diff12 <= 0 ||
1752 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1753 			 && i++ < 20);
1754 	}
1755 
1756 	return c2;
1757 }
1758 
1759 /*
1760  * This function has to be called at least every 64 seconds.  The bus_time
1761  * field stores not only the upper 25 bits of the BUS_TIME register but also
1762  * the most significant bit of the cycle timer in bit 6 so that we can detect
1763  * changes in this bit.
1764  */
1765 static u32 update_bus_time(struct fw_ohci *ohci)
1766 {
1767 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1768 
1769 	if (unlikely(!ohci->bus_time_running)) {
1770 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds);
1771 		ohci->bus_time = (lower_32_bits(get_seconds()) & ~0x7f) |
1772 		                 (cycle_time_seconds & 0x40);
1773 		ohci->bus_time_running = true;
1774 	}
1775 
1776 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1777 		ohci->bus_time += 0x40;
1778 
1779 	return ohci->bus_time | cycle_time_seconds;
1780 }
1781 
1782 static int get_status_for_port(struct fw_ohci *ohci, int port_index)
1783 {
1784 	int reg;
1785 
1786 	mutex_lock(&ohci->phy_reg_mutex);
1787 	reg = write_phy_reg(ohci, 7, port_index);
1788 	if (reg >= 0)
1789 		reg = read_phy_reg(ohci, 8);
1790 	mutex_unlock(&ohci->phy_reg_mutex);
1791 	if (reg < 0)
1792 		return reg;
1793 
1794 	switch (reg & 0x0f) {
1795 	case 0x06:
1796 		return 2;	/* is child node (connected to parent node) */
1797 	case 0x0e:
1798 		return 3;	/* is parent node (connected to child node) */
1799 	}
1800 	return 1;		/* not connected */
1801 }
1802 
1803 static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
1804 	int self_id_count)
1805 {
1806 	int i;
1807 	u32 entry;
1808 
1809 	for (i = 0; i < self_id_count; i++) {
1810 		entry = ohci->self_id_buffer[i];
1811 		if ((self_id & 0xff000000) == (entry & 0xff000000))
1812 			return -1;
1813 		if ((self_id & 0xff000000) < (entry & 0xff000000))
1814 			return i;
1815 	}
1816 	return i;
1817 }
1818 
1819 static int initiated_reset(struct fw_ohci *ohci)
1820 {
1821 	int reg;
1822 	int ret = 0;
1823 
1824 	mutex_lock(&ohci->phy_reg_mutex);
1825 	reg = write_phy_reg(ohci, 7, 0xe0); /* Select page 7 */
1826 	if (reg >= 0) {
1827 		reg = read_phy_reg(ohci, 8);
1828 		reg |= 0x40;
1829 		reg = write_phy_reg(ohci, 8, reg); /* set PMODE bit */
1830 		if (reg >= 0) {
1831 			reg = read_phy_reg(ohci, 12); /* read register 12 */
1832 			if (reg >= 0) {
1833 				if ((reg & 0x08) == 0x08) {
1834 					/* bit 3 indicates "initiated reset" */
1835 					ret = 0x2;
1836 				}
1837 			}
1838 		}
1839 	}
1840 	mutex_unlock(&ohci->phy_reg_mutex);
1841 	return ret;
1842 }
1843 
1844 /*
1845  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
1846  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
1847  * Construct the selfID from phy register contents.
1848  */
1849 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
1850 {
1851 	int reg, i, pos, status;
1852 	/* link active 1, speed 3, bridge 0, contender 1, more packets 0 */
1853 	u32 self_id = 0x8040c800;
1854 
1855 	reg = reg_read(ohci, OHCI1394_NodeID);
1856 	if (!(reg & OHCI1394_NodeID_idValid)) {
1857 		ohci_notice(ohci,
1858 			    "node ID not valid, new bus reset in progress\n");
1859 		return -EBUSY;
1860 	}
1861 	self_id |= ((reg & 0x3f) << 24); /* phy ID */
1862 
1863 	reg = ohci_read_phy_reg(&ohci->card, 4);
1864 	if (reg < 0)
1865 		return reg;
1866 	self_id |= ((reg & 0x07) << 8); /* power class */
1867 
1868 	reg = ohci_read_phy_reg(&ohci->card, 1);
1869 	if (reg < 0)
1870 		return reg;
1871 	self_id |= ((reg & 0x3f) << 16); /* gap count */
1872 
1873 	for (i = 0; i < 3; i++) {
1874 		status = get_status_for_port(ohci, i);
1875 		if (status < 0)
1876 			return status;
1877 		self_id |= ((status & 0x3) << (6 - (i * 2)));
1878 	}
1879 
1880 	self_id |= initiated_reset(ohci);
1881 
1882 	pos = get_self_id_pos(ohci, self_id, self_id_count);
1883 	if (pos >= 0) {
1884 		memmove(&(ohci->self_id_buffer[pos+1]),
1885 			&(ohci->self_id_buffer[pos]),
1886 			(self_id_count - pos) * sizeof(*ohci->self_id_buffer));
1887 		ohci->self_id_buffer[pos] = self_id;
1888 		self_id_count++;
1889 	}
1890 	return self_id_count;
1891 }
1892 
1893 static void bus_reset_work(struct work_struct *work)
1894 {
1895 	struct fw_ohci *ohci =
1896 		container_of(work, struct fw_ohci, bus_reset_work);
1897 	int self_id_count, generation, new_generation, i, j;
1898 	u32 reg;
1899 	void *free_rom = NULL;
1900 	dma_addr_t free_rom_bus = 0;
1901 	bool is_new_root;
1902 
1903 	reg = reg_read(ohci, OHCI1394_NodeID);
1904 	if (!(reg & OHCI1394_NodeID_idValid)) {
1905 		ohci_notice(ohci,
1906 			    "node ID not valid, new bus reset in progress\n");
1907 		return;
1908 	}
1909 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1910 		ohci_notice(ohci, "malconfigured bus\n");
1911 		return;
1912 	}
1913 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1914 			       OHCI1394_NodeID_nodeNumber);
1915 
1916 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1917 	if (!(ohci->is_root && is_new_root))
1918 		reg_write(ohci, OHCI1394_LinkControlSet,
1919 			  OHCI1394_LinkControl_cycleMaster);
1920 	ohci->is_root = is_new_root;
1921 
1922 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1923 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1924 		ohci_notice(ohci, "self ID receive error\n");
1925 		return;
1926 	}
1927 	/*
1928 	 * The count in the SelfIDCount register is the number of
1929 	 * bytes in the self ID receive buffer.  Since we also receive
1930 	 * the inverted quadlets and a header quadlet, we shift one
1931 	 * bit extra to get the actual number of self IDs.
1932 	 */
1933 	self_id_count = (reg >> 3) & 0xff;
1934 
1935 	if (self_id_count > 252) {
1936 		ohci_notice(ohci, "bad selfIDSize (%08x)\n", reg);
1937 		return;
1938 	}
1939 
1940 	generation = (cond_le32_to_cpu(ohci->self_id[0]) >> 16) & 0xff;
1941 	rmb();
1942 
1943 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1944 		u32 id  = cond_le32_to_cpu(ohci->self_id[i]);
1945 		u32 id2 = cond_le32_to_cpu(ohci->self_id[i + 1]);
1946 
1947 		if (id != ~id2) {
1948 			/*
1949 			 * If the invalid data looks like a cycle start packet,
1950 			 * it's likely to be the result of the cycle master
1951 			 * having a wrong gap count.  In this case, the self IDs
1952 			 * so far are valid and should be processed so that the
1953 			 * bus manager can then correct the gap count.
1954 			 */
1955 			if (id == 0xffff008f) {
1956 				ohci_notice(ohci, "ignoring spurious self IDs\n");
1957 				self_id_count = j;
1958 				break;
1959 			}
1960 
1961 			ohci_notice(ohci, "bad self ID %d/%d (%08x != ~%08x)\n",
1962 				    j, self_id_count, id, id2);
1963 			return;
1964 		}
1965 		ohci->self_id_buffer[j] = id;
1966 	}
1967 
1968 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
1969 		self_id_count = find_and_insert_self_id(ohci, self_id_count);
1970 		if (self_id_count < 0) {
1971 			ohci_notice(ohci,
1972 				    "could not construct local self ID\n");
1973 			return;
1974 		}
1975 	}
1976 
1977 	if (self_id_count == 0) {
1978 		ohci_notice(ohci, "no self IDs\n");
1979 		return;
1980 	}
1981 	rmb();
1982 
1983 	/*
1984 	 * Check the consistency of the self IDs we just read.  The
1985 	 * problem we face is that a new bus reset can start while we
1986 	 * read out the self IDs from the DMA buffer. If this happens,
1987 	 * the DMA buffer will be overwritten with new self IDs and we
1988 	 * will read out inconsistent data.  The OHCI specification
1989 	 * (section 11.2) recommends a technique similar to
1990 	 * linux/seqlock.h, where we remember the generation of the
1991 	 * self IDs in the buffer before reading them out and compare
1992 	 * it to the current generation after reading them out.  If
1993 	 * the two generations match we know we have a consistent set
1994 	 * of self IDs.
1995 	 */
1996 
1997 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1998 	if (new_generation != generation) {
1999 		ohci_notice(ohci, "new bus reset, discarding self ids\n");
2000 		return;
2001 	}
2002 
2003 	/* FIXME: Document how the locking works. */
2004 	spin_lock_irq(&ohci->lock);
2005 
2006 	ohci->generation = -1; /* prevent AT packet queueing */
2007 	context_stop(&ohci->at_request_ctx);
2008 	context_stop(&ohci->at_response_ctx);
2009 
2010 	spin_unlock_irq(&ohci->lock);
2011 
2012 	/*
2013 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
2014 	 * packets in the AT queues and software needs to drain them.
2015 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
2016 	 */
2017 	at_context_flush(&ohci->at_request_ctx);
2018 	at_context_flush(&ohci->at_response_ctx);
2019 
2020 	spin_lock_irq(&ohci->lock);
2021 
2022 	ohci->generation = generation;
2023 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
2024 
2025 	if (ohci->quirks & QUIRK_RESET_PACKET)
2026 		ohci->request_generation = generation;
2027 
2028 	/*
2029 	 * This next bit is unrelated to the AT context stuff but we
2030 	 * have to do it under the spinlock also.  If a new config rom
2031 	 * was set up before this reset, the old one is now no longer
2032 	 * in use and we can free it. Update the config rom pointers
2033 	 * to point to the current config rom and clear the
2034 	 * next_config_rom pointer so a new update can take place.
2035 	 */
2036 
2037 	if (ohci->next_config_rom != NULL) {
2038 		if (ohci->next_config_rom != ohci->config_rom) {
2039 			free_rom      = ohci->config_rom;
2040 			free_rom_bus  = ohci->config_rom_bus;
2041 		}
2042 		ohci->config_rom      = ohci->next_config_rom;
2043 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
2044 		ohci->next_config_rom = NULL;
2045 
2046 		/*
2047 		 * Restore config_rom image and manually update
2048 		 * config_rom registers.  Writing the header quadlet
2049 		 * will indicate that the config rom is ready, so we
2050 		 * do that last.
2051 		 */
2052 		reg_write(ohci, OHCI1394_BusOptions,
2053 			  be32_to_cpu(ohci->config_rom[2]));
2054 		ohci->config_rom[0] = ohci->next_header;
2055 		reg_write(ohci, OHCI1394_ConfigROMhdr,
2056 			  be32_to_cpu(ohci->next_header));
2057 	}
2058 
2059 	if (param_remote_dma) {
2060 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
2061 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
2062 	}
2063 
2064 	spin_unlock_irq(&ohci->lock);
2065 
2066 	if (free_rom)
2067 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2068 				  free_rom, free_rom_bus);
2069 
2070 	log_selfids(ohci, generation, self_id_count);
2071 
2072 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
2073 				 self_id_count, ohci->self_id_buffer,
2074 				 ohci->csr_state_setclear_abdicate);
2075 	ohci->csr_state_setclear_abdicate = false;
2076 }
2077 
2078 static irqreturn_t irq_handler(int irq, void *data)
2079 {
2080 	struct fw_ohci *ohci = data;
2081 	u32 event, iso_event;
2082 	int i;
2083 
2084 	event = reg_read(ohci, OHCI1394_IntEventClear);
2085 
2086 	if (!event || !~event)
2087 		return IRQ_NONE;
2088 
2089 	/*
2090 	 * busReset and postedWriteErr must not be cleared yet
2091 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
2092 	 */
2093 	reg_write(ohci, OHCI1394_IntEventClear,
2094 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
2095 	log_irqs(ohci, event);
2096 
2097 	if (event & OHCI1394_selfIDComplete)
2098 		queue_work(selfid_workqueue, &ohci->bus_reset_work);
2099 
2100 	if (event & OHCI1394_RQPkt)
2101 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
2102 
2103 	if (event & OHCI1394_RSPkt)
2104 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
2105 
2106 	if (event & OHCI1394_reqTxComplete)
2107 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
2108 
2109 	if (event & OHCI1394_respTxComplete)
2110 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
2111 
2112 	if (event & OHCI1394_isochRx) {
2113 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
2114 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
2115 
2116 		while (iso_event) {
2117 			i = ffs(iso_event) - 1;
2118 			tasklet_schedule(
2119 				&ohci->ir_context_list[i].context.tasklet);
2120 			iso_event &= ~(1 << i);
2121 		}
2122 	}
2123 
2124 	if (event & OHCI1394_isochTx) {
2125 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
2126 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
2127 
2128 		while (iso_event) {
2129 			i = ffs(iso_event) - 1;
2130 			tasklet_schedule(
2131 				&ohci->it_context_list[i].context.tasklet);
2132 			iso_event &= ~(1 << i);
2133 		}
2134 	}
2135 
2136 	if (unlikely(event & OHCI1394_regAccessFail))
2137 		ohci_err(ohci, "register access failure\n");
2138 
2139 	if (unlikely(event & OHCI1394_postedWriteErr)) {
2140 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
2141 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
2142 		reg_write(ohci, OHCI1394_IntEventClear,
2143 			  OHCI1394_postedWriteErr);
2144 		if (printk_ratelimit())
2145 			ohci_err(ohci, "PCI posted write error\n");
2146 	}
2147 
2148 	if (unlikely(event & OHCI1394_cycleTooLong)) {
2149 		if (printk_ratelimit())
2150 			ohci_notice(ohci, "isochronous cycle too long\n");
2151 		reg_write(ohci, OHCI1394_LinkControlSet,
2152 			  OHCI1394_LinkControl_cycleMaster);
2153 	}
2154 
2155 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
2156 		/*
2157 		 * We need to clear this event bit in order to make
2158 		 * cycleMatch isochronous I/O work.  In theory we should
2159 		 * stop active cycleMatch iso contexts now and restart
2160 		 * them at least two cycles later.  (FIXME?)
2161 		 */
2162 		if (printk_ratelimit())
2163 			ohci_notice(ohci, "isochronous cycle inconsistent\n");
2164 	}
2165 
2166 	if (unlikely(event & OHCI1394_unrecoverableError))
2167 		handle_dead_contexts(ohci);
2168 
2169 	if (event & OHCI1394_cycle64Seconds) {
2170 		spin_lock(&ohci->lock);
2171 		update_bus_time(ohci);
2172 		spin_unlock(&ohci->lock);
2173 	} else
2174 		flush_writes(ohci);
2175 
2176 	return IRQ_HANDLED;
2177 }
2178 
2179 static int software_reset(struct fw_ohci *ohci)
2180 {
2181 	u32 val;
2182 	int i;
2183 
2184 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
2185 	for (i = 0; i < 500; i++) {
2186 		val = reg_read(ohci, OHCI1394_HCControlSet);
2187 		if (!~val)
2188 			return -ENODEV; /* Card was ejected. */
2189 
2190 		if (!(val & OHCI1394_HCControl_softReset))
2191 			return 0;
2192 
2193 		msleep(1);
2194 	}
2195 
2196 	return -EBUSY;
2197 }
2198 
2199 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
2200 {
2201 	size_t size = length * 4;
2202 
2203 	memcpy(dest, src, size);
2204 	if (size < CONFIG_ROM_SIZE)
2205 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
2206 }
2207 
2208 static int configure_1394a_enhancements(struct fw_ohci *ohci)
2209 {
2210 	bool enable_1394a;
2211 	int ret, clear, set, offset;
2212 
2213 	/* Check if the driver should configure link and PHY. */
2214 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
2215 	      OHCI1394_HCControl_programPhyEnable))
2216 		return 0;
2217 
2218 	/* Paranoia: check whether the PHY supports 1394a, too. */
2219 	enable_1394a = false;
2220 	ret = read_phy_reg(ohci, 2);
2221 	if (ret < 0)
2222 		return ret;
2223 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2224 		ret = read_paged_phy_reg(ohci, 1, 8);
2225 		if (ret < 0)
2226 			return ret;
2227 		if (ret >= 1)
2228 			enable_1394a = true;
2229 	}
2230 
2231 	if (ohci->quirks & QUIRK_NO_1394A)
2232 		enable_1394a = false;
2233 
2234 	/* Configure PHY and link consistently. */
2235 	if (enable_1394a) {
2236 		clear = 0;
2237 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2238 	} else {
2239 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2240 		set = 0;
2241 	}
2242 	ret = update_phy_reg(ohci, 5, clear, set);
2243 	if (ret < 0)
2244 		return ret;
2245 
2246 	if (enable_1394a)
2247 		offset = OHCI1394_HCControlSet;
2248 	else
2249 		offset = OHCI1394_HCControlClear;
2250 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2251 
2252 	/* Clean up: configuration has been taken care of. */
2253 	reg_write(ohci, OHCI1394_HCControlClear,
2254 		  OHCI1394_HCControl_programPhyEnable);
2255 
2256 	return 0;
2257 }
2258 
2259 static int probe_tsb41ba3d(struct fw_ohci *ohci)
2260 {
2261 	/* TI vendor ID = 0x080028, TSB41BA3D product ID = 0x833005 (sic) */
2262 	static const u8 id[] = { 0x08, 0x00, 0x28, 0x83, 0x30, 0x05, };
2263 	int reg, i;
2264 
2265 	reg = read_phy_reg(ohci, 2);
2266 	if (reg < 0)
2267 		return reg;
2268 	if ((reg & PHY_EXTENDED_REGISTERS) != PHY_EXTENDED_REGISTERS)
2269 		return 0;
2270 
2271 	for (i = ARRAY_SIZE(id) - 1; i >= 0; i--) {
2272 		reg = read_paged_phy_reg(ohci, 1, i + 10);
2273 		if (reg < 0)
2274 			return reg;
2275 		if (reg != id[i])
2276 			return 0;
2277 	}
2278 	return 1;
2279 }
2280 
2281 static int ohci_enable(struct fw_card *card,
2282 		       const __be32 *config_rom, size_t length)
2283 {
2284 	struct fw_ohci *ohci = fw_ohci(card);
2285 	u32 lps, version, irqs;
2286 	int i, ret;
2287 
2288 	if (software_reset(ohci)) {
2289 		ohci_err(ohci, "failed to reset ohci card\n");
2290 		return -EBUSY;
2291 	}
2292 
2293 	/*
2294 	 * Now enable LPS, which we need in order to start accessing
2295 	 * most of the registers.  In fact, on some cards (ALI M5251),
2296 	 * accessing registers in the SClk domain without LPS enabled
2297 	 * will lock up the machine.  Wait 50msec to make sure we have
2298 	 * full link enabled.  However, with some cards (well, at least
2299 	 * a JMicron PCIe card), we have to try again sometimes.
2300 	 *
2301 	 * TI TSB82AA2 + TSB81BA3(A) cards signal LPS enabled early but
2302 	 * cannot actually use the phy at that time.  These need tens of
2303 	 * millisecods pause between LPS write and first phy access too.
2304 	 */
2305 
2306 	reg_write(ohci, OHCI1394_HCControlSet,
2307 		  OHCI1394_HCControl_LPS |
2308 		  OHCI1394_HCControl_postedWriteEnable);
2309 	flush_writes(ohci);
2310 
2311 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2312 		msleep(50);
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, FW_MAX_PHYSICAL_RANGE >> 16);
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 	struct fw_ohci *ohci = fw_ohci(card);
2591 	unsigned long flags;
2592 	int n, ret = 0;
2593 
2594 	if (param_remote_dma)
2595 		return 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 }
2626 
2627 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2628 {
2629 	struct fw_ohci *ohci = fw_ohci(card);
2630 	unsigned long flags;
2631 	u32 value;
2632 
2633 	switch (csr_offset) {
2634 	case CSR_STATE_CLEAR:
2635 	case CSR_STATE_SET:
2636 		if (ohci->is_root &&
2637 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2638 		     OHCI1394_LinkControl_cycleMaster))
2639 			value = CSR_STATE_BIT_CMSTR;
2640 		else
2641 			value = 0;
2642 		if (ohci->csr_state_setclear_abdicate)
2643 			value |= CSR_STATE_BIT_ABDICATE;
2644 
2645 		return value;
2646 
2647 	case CSR_NODE_IDS:
2648 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2649 
2650 	case CSR_CYCLE_TIME:
2651 		return get_cycle_time(ohci);
2652 
2653 	case CSR_BUS_TIME:
2654 		/*
2655 		 * We might be called just after the cycle timer has wrapped
2656 		 * around but just before the cycle64Seconds handler, so we
2657 		 * better check here, too, if the bus time needs to be updated.
2658 		 */
2659 		spin_lock_irqsave(&ohci->lock, flags);
2660 		value = update_bus_time(ohci);
2661 		spin_unlock_irqrestore(&ohci->lock, flags);
2662 		return value;
2663 
2664 	case CSR_BUSY_TIMEOUT:
2665 		value = reg_read(ohci, OHCI1394_ATRetries);
2666 		return (value >> 4) & 0x0ffff00f;
2667 
2668 	case CSR_PRIORITY_BUDGET:
2669 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2670 			(ohci->pri_req_max << 8);
2671 
2672 	default:
2673 		WARN_ON(1);
2674 		return 0;
2675 	}
2676 }
2677 
2678 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2679 {
2680 	struct fw_ohci *ohci = fw_ohci(card);
2681 	unsigned long flags;
2682 
2683 	switch (csr_offset) {
2684 	case CSR_STATE_CLEAR:
2685 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2686 			reg_write(ohci, OHCI1394_LinkControlClear,
2687 				  OHCI1394_LinkControl_cycleMaster);
2688 			flush_writes(ohci);
2689 		}
2690 		if (value & CSR_STATE_BIT_ABDICATE)
2691 			ohci->csr_state_setclear_abdicate = false;
2692 		break;
2693 
2694 	case CSR_STATE_SET:
2695 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2696 			reg_write(ohci, OHCI1394_LinkControlSet,
2697 				  OHCI1394_LinkControl_cycleMaster);
2698 			flush_writes(ohci);
2699 		}
2700 		if (value & CSR_STATE_BIT_ABDICATE)
2701 			ohci->csr_state_setclear_abdicate = true;
2702 		break;
2703 
2704 	case CSR_NODE_IDS:
2705 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2706 		flush_writes(ohci);
2707 		break;
2708 
2709 	case CSR_CYCLE_TIME:
2710 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2711 		reg_write(ohci, OHCI1394_IntEventSet,
2712 			  OHCI1394_cycleInconsistent);
2713 		flush_writes(ohci);
2714 		break;
2715 
2716 	case CSR_BUS_TIME:
2717 		spin_lock_irqsave(&ohci->lock, flags);
2718 		ohci->bus_time = (update_bus_time(ohci) & 0x40) |
2719 		                 (value & ~0x7f);
2720 		spin_unlock_irqrestore(&ohci->lock, flags);
2721 		break;
2722 
2723 	case CSR_BUSY_TIMEOUT:
2724 		value = (value & 0xf) | ((value & 0xf) << 4) |
2725 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2726 		reg_write(ohci, OHCI1394_ATRetries, value);
2727 		flush_writes(ohci);
2728 		break;
2729 
2730 	case CSR_PRIORITY_BUDGET:
2731 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2732 		flush_writes(ohci);
2733 		break;
2734 
2735 	default:
2736 		WARN_ON(1);
2737 		break;
2738 	}
2739 }
2740 
2741 static void flush_iso_completions(struct iso_context *ctx)
2742 {
2743 	ctx->base.callback.sc(&ctx->base, ctx->last_timestamp,
2744 			      ctx->header_length, ctx->header,
2745 			      ctx->base.callback_data);
2746 	ctx->header_length = 0;
2747 }
2748 
2749 static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
2750 {
2751 	u32 *ctx_hdr;
2752 
2753 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
2754 		if (ctx->base.drop_overflow_headers)
2755 			return;
2756 		flush_iso_completions(ctx);
2757 	}
2758 
2759 	ctx_hdr = ctx->header + ctx->header_length;
2760 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
2761 
2762 	/*
2763 	 * The two iso header quadlets are byteswapped to little
2764 	 * endian by the controller, but we want to present them
2765 	 * as big endian for consistency with the bus endianness.
2766 	 */
2767 	if (ctx->base.header_size > 0)
2768 		ctx_hdr[0] = swab32(dma_hdr[1]); /* iso packet header */
2769 	if (ctx->base.header_size > 4)
2770 		ctx_hdr[1] = swab32(dma_hdr[0]); /* timestamp */
2771 	if (ctx->base.header_size > 8)
2772 		memcpy(&ctx_hdr[2], &dma_hdr[2], ctx->base.header_size - 8);
2773 	ctx->header_length += ctx->base.header_size;
2774 }
2775 
2776 static int handle_ir_packet_per_buffer(struct context *context,
2777 				       struct descriptor *d,
2778 				       struct descriptor *last)
2779 {
2780 	struct iso_context *ctx =
2781 		container_of(context, struct iso_context, context);
2782 	struct descriptor *pd;
2783 	u32 buffer_dma;
2784 
2785 	for (pd = d; pd <= last; pd++)
2786 		if (pd->transfer_status)
2787 			break;
2788 	if (pd > last)
2789 		/* Descriptor(s) not done yet, stop iteration */
2790 		return 0;
2791 
2792 	while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
2793 		d++;
2794 		buffer_dma = le32_to_cpu(d->data_address);
2795 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2796 					      buffer_dma & PAGE_MASK,
2797 					      buffer_dma & ~PAGE_MASK,
2798 					      le16_to_cpu(d->req_count),
2799 					      DMA_FROM_DEVICE);
2800 	}
2801 
2802 	copy_iso_headers(ctx, (u32 *) (last + 1));
2803 
2804 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2805 		flush_iso_completions(ctx);
2806 
2807 	return 1;
2808 }
2809 
2810 /* d == last because each descriptor block is only a single descriptor. */
2811 static int handle_ir_buffer_fill(struct context *context,
2812 				 struct descriptor *d,
2813 				 struct descriptor *last)
2814 {
2815 	struct iso_context *ctx =
2816 		container_of(context, struct iso_context, context);
2817 	unsigned int req_count, res_count, completed;
2818 	u32 buffer_dma;
2819 
2820 	req_count = le16_to_cpu(last->req_count);
2821 	res_count = le16_to_cpu(ACCESS_ONCE(last->res_count));
2822 	completed = req_count - res_count;
2823 	buffer_dma = le32_to_cpu(last->data_address);
2824 
2825 	if (completed > 0) {
2826 		ctx->mc_buffer_bus = buffer_dma;
2827 		ctx->mc_completed = completed;
2828 	}
2829 
2830 	if (res_count != 0)
2831 		/* Descriptor(s) not done yet, stop iteration */
2832 		return 0;
2833 
2834 	dma_sync_single_range_for_cpu(context->ohci->card.device,
2835 				      buffer_dma & PAGE_MASK,
2836 				      buffer_dma & ~PAGE_MASK,
2837 				      completed, DMA_FROM_DEVICE);
2838 
2839 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) {
2840 		ctx->base.callback.mc(&ctx->base,
2841 				      buffer_dma + completed,
2842 				      ctx->base.callback_data);
2843 		ctx->mc_completed = 0;
2844 	}
2845 
2846 	return 1;
2847 }
2848 
2849 static void flush_ir_buffer_fill(struct iso_context *ctx)
2850 {
2851 	dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
2852 				      ctx->mc_buffer_bus & PAGE_MASK,
2853 				      ctx->mc_buffer_bus & ~PAGE_MASK,
2854 				      ctx->mc_completed, DMA_FROM_DEVICE);
2855 
2856 	ctx->base.callback.mc(&ctx->base,
2857 			      ctx->mc_buffer_bus + ctx->mc_completed,
2858 			      ctx->base.callback_data);
2859 	ctx->mc_completed = 0;
2860 }
2861 
2862 static inline void sync_it_packet_for_cpu(struct context *context,
2863 					  struct descriptor *pd)
2864 {
2865 	__le16 control;
2866 	u32 buffer_dma;
2867 
2868 	/* only packets beginning with OUTPUT_MORE* have data buffers */
2869 	if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2870 		return;
2871 
2872 	/* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
2873 	pd += 2;
2874 
2875 	/*
2876 	 * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
2877 	 * data buffer is in the context program's coherent page and must not
2878 	 * be synced.
2879 	 */
2880 	if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
2881 	    (context->current_bus          & PAGE_MASK)) {
2882 		if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2883 			return;
2884 		pd++;
2885 	}
2886 
2887 	do {
2888 		buffer_dma = le32_to_cpu(pd->data_address);
2889 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2890 					      buffer_dma & PAGE_MASK,
2891 					      buffer_dma & ~PAGE_MASK,
2892 					      le16_to_cpu(pd->req_count),
2893 					      DMA_TO_DEVICE);
2894 		control = pd->control;
2895 		pd++;
2896 	} while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
2897 }
2898 
2899 static int handle_it_packet(struct context *context,
2900 			    struct descriptor *d,
2901 			    struct descriptor *last)
2902 {
2903 	struct iso_context *ctx =
2904 		container_of(context, struct iso_context, context);
2905 	struct descriptor *pd;
2906 	__be32 *ctx_hdr;
2907 
2908 	for (pd = d; pd <= last; pd++)
2909 		if (pd->transfer_status)
2910 			break;
2911 	if (pd > last)
2912 		/* Descriptor(s) not done yet, stop iteration */
2913 		return 0;
2914 
2915 	sync_it_packet_for_cpu(context, d);
2916 
2917 	if (ctx->header_length + 4 > PAGE_SIZE) {
2918 		if (ctx->base.drop_overflow_headers)
2919 			return 1;
2920 		flush_iso_completions(ctx);
2921 	}
2922 
2923 	ctx_hdr = ctx->header + ctx->header_length;
2924 	ctx->last_timestamp = le16_to_cpu(last->res_count);
2925 	/* Present this value as big-endian to match the receive code */
2926 	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
2927 			       le16_to_cpu(pd->res_count));
2928 	ctx->header_length += 4;
2929 
2930 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2931 		flush_iso_completions(ctx);
2932 
2933 	return 1;
2934 }
2935 
2936 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2937 {
2938 	u32 hi = channels >> 32, lo = channels;
2939 
2940 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2941 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2942 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2943 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2944 	mmiowb();
2945 	ohci->mc_channels = channels;
2946 }
2947 
2948 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2949 				int type, int channel, size_t header_size)
2950 {
2951 	struct fw_ohci *ohci = fw_ohci(card);
2952 	struct iso_context *uninitialized_var(ctx);
2953 	descriptor_callback_t uninitialized_var(callback);
2954 	u64 *uninitialized_var(channels);
2955 	u32 *uninitialized_var(mask), uninitialized_var(regs);
2956 	int index, ret = -EBUSY;
2957 
2958 	spin_lock_irq(&ohci->lock);
2959 
2960 	switch (type) {
2961 	case FW_ISO_CONTEXT_TRANSMIT:
2962 		mask     = &ohci->it_context_mask;
2963 		callback = handle_it_packet;
2964 		index    = ffs(*mask) - 1;
2965 		if (index >= 0) {
2966 			*mask &= ~(1 << index);
2967 			regs = OHCI1394_IsoXmitContextBase(index);
2968 			ctx  = &ohci->it_context_list[index];
2969 		}
2970 		break;
2971 
2972 	case FW_ISO_CONTEXT_RECEIVE:
2973 		channels = &ohci->ir_context_channels;
2974 		mask     = &ohci->ir_context_mask;
2975 		callback = handle_ir_packet_per_buffer;
2976 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2977 		if (index >= 0) {
2978 			*channels &= ~(1ULL << channel);
2979 			*mask     &= ~(1 << index);
2980 			regs = OHCI1394_IsoRcvContextBase(index);
2981 			ctx  = &ohci->ir_context_list[index];
2982 		}
2983 		break;
2984 
2985 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2986 		mask     = &ohci->ir_context_mask;
2987 		callback = handle_ir_buffer_fill;
2988 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2989 		if (index >= 0) {
2990 			ohci->mc_allocated = true;
2991 			*mask &= ~(1 << index);
2992 			regs = OHCI1394_IsoRcvContextBase(index);
2993 			ctx  = &ohci->ir_context_list[index];
2994 		}
2995 		break;
2996 
2997 	default:
2998 		index = -1;
2999 		ret = -ENOSYS;
3000 	}
3001 
3002 	spin_unlock_irq(&ohci->lock);
3003 
3004 	if (index < 0)
3005 		return ERR_PTR(ret);
3006 
3007 	memset(ctx, 0, sizeof(*ctx));
3008 	ctx->header_length = 0;
3009 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
3010 	if (ctx->header == NULL) {
3011 		ret = -ENOMEM;
3012 		goto out;
3013 	}
3014 	ret = context_init(&ctx->context, ohci, regs, callback);
3015 	if (ret < 0)
3016 		goto out_with_header;
3017 
3018 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
3019 		set_multichannel_mask(ohci, 0);
3020 		ctx->mc_completed = 0;
3021 	}
3022 
3023 	return &ctx->base;
3024 
3025  out_with_header:
3026 	free_page((unsigned long)ctx->header);
3027  out:
3028 	spin_lock_irq(&ohci->lock);
3029 
3030 	switch (type) {
3031 	case FW_ISO_CONTEXT_RECEIVE:
3032 		*channels |= 1ULL << channel;
3033 		break;
3034 
3035 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3036 		ohci->mc_allocated = false;
3037 		break;
3038 	}
3039 	*mask |= 1 << index;
3040 
3041 	spin_unlock_irq(&ohci->lock);
3042 
3043 	return ERR_PTR(ret);
3044 }
3045 
3046 static int ohci_start_iso(struct fw_iso_context *base,
3047 			  s32 cycle, u32 sync, u32 tags)
3048 {
3049 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3050 	struct fw_ohci *ohci = ctx->context.ohci;
3051 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
3052 	int index;
3053 
3054 	/* the controller cannot start without any queued packets */
3055 	if (ctx->context.last->branch_address == 0)
3056 		return -ENODATA;
3057 
3058 	switch (ctx->base.type) {
3059 	case FW_ISO_CONTEXT_TRANSMIT:
3060 		index = ctx - ohci->it_context_list;
3061 		match = 0;
3062 		if (cycle >= 0)
3063 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
3064 				(cycle & 0x7fff) << 16;
3065 
3066 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
3067 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
3068 		context_run(&ctx->context, match);
3069 		break;
3070 
3071 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3072 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
3073 		/* fall through */
3074 	case FW_ISO_CONTEXT_RECEIVE:
3075 		index = ctx - ohci->ir_context_list;
3076 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
3077 		if (cycle >= 0) {
3078 			match |= (cycle & 0x07fff) << 12;
3079 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
3080 		}
3081 
3082 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
3083 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
3084 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
3085 		context_run(&ctx->context, control);
3086 
3087 		ctx->sync = sync;
3088 		ctx->tags = tags;
3089 
3090 		break;
3091 	}
3092 
3093 	return 0;
3094 }
3095 
3096 static int ohci_stop_iso(struct fw_iso_context *base)
3097 {
3098 	struct fw_ohci *ohci = fw_ohci(base->card);
3099 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3100 	int index;
3101 
3102 	switch (ctx->base.type) {
3103 	case FW_ISO_CONTEXT_TRANSMIT:
3104 		index = ctx - ohci->it_context_list;
3105 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
3106 		break;
3107 
3108 	case FW_ISO_CONTEXT_RECEIVE:
3109 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3110 		index = ctx - ohci->ir_context_list;
3111 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
3112 		break;
3113 	}
3114 	flush_writes(ohci);
3115 	context_stop(&ctx->context);
3116 	tasklet_kill(&ctx->context.tasklet);
3117 
3118 	return 0;
3119 }
3120 
3121 static void ohci_free_iso_context(struct fw_iso_context *base)
3122 {
3123 	struct fw_ohci *ohci = fw_ohci(base->card);
3124 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3125 	unsigned long flags;
3126 	int index;
3127 
3128 	ohci_stop_iso(base);
3129 	context_release(&ctx->context);
3130 	free_page((unsigned long)ctx->header);
3131 
3132 	spin_lock_irqsave(&ohci->lock, flags);
3133 
3134 	switch (base->type) {
3135 	case FW_ISO_CONTEXT_TRANSMIT:
3136 		index = ctx - ohci->it_context_list;
3137 		ohci->it_context_mask |= 1 << index;
3138 		break;
3139 
3140 	case FW_ISO_CONTEXT_RECEIVE:
3141 		index = ctx - ohci->ir_context_list;
3142 		ohci->ir_context_mask |= 1 << index;
3143 		ohci->ir_context_channels |= 1ULL << base->channel;
3144 		break;
3145 
3146 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3147 		index = ctx - ohci->ir_context_list;
3148 		ohci->ir_context_mask |= 1 << index;
3149 		ohci->ir_context_channels |= ohci->mc_channels;
3150 		ohci->mc_channels = 0;
3151 		ohci->mc_allocated = false;
3152 		break;
3153 	}
3154 
3155 	spin_unlock_irqrestore(&ohci->lock, flags);
3156 }
3157 
3158 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
3159 {
3160 	struct fw_ohci *ohci = fw_ohci(base->card);
3161 	unsigned long flags;
3162 	int ret;
3163 
3164 	switch (base->type) {
3165 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3166 
3167 		spin_lock_irqsave(&ohci->lock, flags);
3168 
3169 		/* Don't allow multichannel to grab other contexts' channels. */
3170 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
3171 			*channels = ohci->ir_context_channels;
3172 			ret = -EBUSY;
3173 		} else {
3174 			set_multichannel_mask(ohci, *channels);
3175 			ret = 0;
3176 		}
3177 
3178 		spin_unlock_irqrestore(&ohci->lock, flags);
3179 
3180 		break;
3181 	default:
3182 		ret = -EINVAL;
3183 	}
3184 
3185 	return ret;
3186 }
3187 
3188 #ifdef CONFIG_PM
3189 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
3190 {
3191 	int i;
3192 	struct iso_context *ctx;
3193 
3194 	for (i = 0 ; i < ohci->n_ir ; i++) {
3195 		ctx = &ohci->ir_context_list[i];
3196 		if (ctx->context.running)
3197 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3198 	}
3199 
3200 	for (i = 0 ; i < ohci->n_it ; i++) {
3201 		ctx = &ohci->it_context_list[i];
3202 		if (ctx->context.running)
3203 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3204 	}
3205 }
3206 #endif
3207 
3208 static int queue_iso_transmit(struct iso_context *ctx,
3209 			      struct fw_iso_packet *packet,
3210 			      struct fw_iso_buffer *buffer,
3211 			      unsigned long payload)
3212 {
3213 	struct descriptor *d, *last, *pd;
3214 	struct fw_iso_packet *p;
3215 	__le32 *header;
3216 	dma_addr_t d_bus, page_bus;
3217 	u32 z, header_z, payload_z, irq;
3218 	u32 payload_index, payload_end_index, next_page_index;
3219 	int page, end_page, i, length, offset;
3220 
3221 	p = packet;
3222 	payload_index = payload;
3223 
3224 	if (p->skip)
3225 		z = 1;
3226 	else
3227 		z = 2;
3228 	if (p->header_length > 0)
3229 		z++;
3230 
3231 	/* Determine the first page the payload isn't contained in. */
3232 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
3233 	if (p->payload_length > 0)
3234 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
3235 	else
3236 		payload_z = 0;
3237 
3238 	z += payload_z;
3239 
3240 	/* Get header size in number of descriptors. */
3241 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
3242 
3243 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
3244 	if (d == NULL)
3245 		return -ENOMEM;
3246 
3247 	if (!p->skip) {
3248 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
3249 		d[0].req_count = cpu_to_le16(8);
3250 		/*
3251 		 * Link the skip address to this descriptor itself.  This causes
3252 		 * a context to skip a cycle whenever lost cycles or FIFO
3253 		 * overruns occur, without dropping the data.  The application
3254 		 * should then decide whether this is an error condition or not.
3255 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
3256 		 */
3257 		d[0].branch_address = cpu_to_le32(d_bus | z);
3258 
3259 		header = (__le32 *) &d[1];
3260 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
3261 					IT_HEADER_TAG(p->tag) |
3262 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
3263 					IT_HEADER_CHANNEL(ctx->base.channel) |
3264 					IT_HEADER_SPEED(ctx->base.speed));
3265 		header[1] =
3266 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
3267 							  p->payload_length));
3268 	}
3269 
3270 	if (p->header_length > 0) {
3271 		d[2].req_count    = cpu_to_le16(p->header_length);
3272 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
3273 		memcpy(&d[z], p->header, p->header_length);
3274 	}
3275 
3276 	pd = d + z - payload_z;
3277 	payload_end_index = payload_index + p->payload_length;
3278 	for (i = 0; i < payload_z; i++) {
3279 		page               = payload_index >> PAGE_SHIFT;
3280 		offset             = payload_index & ~PAGE_MASK;
3281 		next_page_index    = (page + 1) << PAGE_SHIFT;
3282 		length             =
3283 			min(next_page_index, payload_end_index) - payload_index;
3284 		pd[i].req_count    = cpu_to_le16(length);
3285 
3286 		page_bus = page_private(buffer->pages[page]);
3287 		pd[i].data_address = cpu_to_le32(page_bus + offset);
3288 
3289 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3290 						 page_bus, offset, length,
3291 						 DMA_TO_DEVICE);
3292 
3293 		payload_index += length;
3294 	}
3295 
3296 	if (p->interrupt)
3297 		irq = DESCRIPTOR_IRQ_ALWAYS;
3298 	else
3299 		irq = DESCRIPTOR_NO_IRQ;
3300 
3301 	last = z == 2 ? d : d + z - 1;
3302 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
3303 				     DESCRIPTOR_STATUS |
3304 				     DESCRIPTOR_BRANCH_ALWAYS |
3305 				     irq);
3306 
3307 	context_append(&ctx->context, d, z, header_z);
3308 
3309 	return 0;
3310 }
3311 
3312 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
3313 				       struct fw_iso_packet *packet,
3314 				       struct fw_iso_buffer *buffer,
3315 				       unsigned long payload)
3316 {
3317 	struct device *device = ctx->context.ohci->card.device;
3318 	struct descriptor *d, *pd;
3319 	dma_addr_t d_bus, page_bus;
3320 	u32 z, header_z, rest;
3321 	int i, j, length;
3322 	int page, offset, packet_count, header_size, payload_per_buffer;
3323 
3324 	/*
3325 	 * The OHCI controller puts the isochronous header and trailer in the
3326 	 * buffer, so we need at least 8 bytes.
3327 	 */
3328 	packet_count = packet->header_length / ctx->base.header_size;
3329 	header_size  = max(ctx->base.header_size, (size_t)8);
3330 
3331 	/* Get header size in number of descriptors. */
3332 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
3333 	page     = payload >> PAGE_SHIFT;
3334 	offset   = payload & ~PAGE_MASK;
3335 	payload_per_buffer = packet->payload_length / packet_count;
3336 
3337 	for (i = 0; i < packet_count; i++) {
3338 		/* d points to the header descriptor */
3339 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
3340 		d = context_get_descriptors(&ctx->context,
3341 				z + header_z, &d_bus);
3342 		if (d == NULL)
3343 			return -ENOMEM;
3344 
3345 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3346 					      DESCRIPTOR_INPUT_MORE);
3347 		if (packet->skip && i == 0)
3348 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3349 		d->req_count    = cpu_to_le16(header_size);
3350 		d->res_count    = d->req_count;
3351 		d->transfer_status = 0;
3352 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3353 
3354 		rest = payload_per_buffer;
3355 		pd = d;
3356 		for (j = 1; j < z; j++) {
3357 			pd++;
3358 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3359 						  DESCRIPTOR_INPUT_MORE);
3360 
3361 			if (offset + rest < PAGE_SIZE)
3362 				length = rest;
3363 			else
3364 				length = PAGE_SIZE - offset;
3365 			pd->req_count = cpu_to_le16(length);
3366 			pd->res_count = pd->req_count;
3367 			pd->transfer_status = 0;
3368 
3369 			page_bus = page_private(buffer->pages[page]);
3370 			pd->data_address = cpu_to_le32(page_bus + offset);
3371 
3372 			dma_sync_single_range_for_device(device, page_bus,
3373 							 offset, length,
3374 							 DMA_FROM_DEVICE);
3375 
3376 			offset = (offset + length) & ~PAGE_MASK;
3377 			rest -= length;
3378 			if (offset == 0)
3379 				page++;
3380 		}
3381 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3382 					  DESCRIPTOR_INPUT_LAST |
3383 					  DESCRIPTOR_BRANCH_ALWAYS);
3384 		if (packet->interrupt && i == packet_count - 1)
3385 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3386 
3387 		context_append(&ctx->context, d, z, header_z);
3388 	}
3389 
3390 	return 0;
3391 }
3392 
3393 static int queue_iso_buffer_fill(struct iso_context *ctx,
3394 				 struct fw_iso_packet *packet,
3395 				 struct fw_iso_buffer *buffer,
3396 				 unsigned long payload)
3397 {
3398 	struct descriptor *d;
3399 	dma_addr_t d_bus, page_bus;
3400 	int page, offset, rest, z, i, length;
3401 
3402 	page   = payload >> PAGE_SHIFT;
3403 	offset = payload & ~PAGE_MASK;
3404 	rest   = packet->payload_length;
3405 
3406 	/* We need one descriptor for each page in the buffer. */
3407 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3408 
3409 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3410 		return -EFAULT;
3411 
3412 	for (i = 0; i < z; i++) {
3413 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3414 		if (d == NULL)
3415 			return -ENOMEM;
3416 
3417 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3418 					 DESCRIPTOR_BRANCH_ALWAYS);
3419 		if (packet->skip && i == 0)
3420 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3421 		if (packet->interrupt && i == z - 1)
3422 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3423 
3424 		if (offset + rest < PAGE_SIZE)
3425 			length = rest;
3426 		else
3427 			length = PAGE_SIZE - offset;
3428 		d->req_count = cpu_to_le16(length);
3429 		d->res_count = d->req_count;
3430 		d->transfer_status = 0;
3431 
3432 		page_bus = page_private(buffer->pages[page]);
3433 		d->data_address = cpu_to_le32(page_bus + offset);
3434 
3435 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3436 						 page_bus, offset, length,
3437 						 DMA_FROM_DEVICE);
3438 
3439 		rest -= length;
3440 		offset = 0;
3441 		page++;
3442 
3443 		context_append(&ctx->context, d, 1, 0);
3444 	}
3445 
3446 	return 0;
3447 }
3448 
3449 static int ohci_queue_iso(struct fw_iso_context *base,
3450 			  struct fw_iso_packet *packet,
3451 			  struct fw_iso_buffer *buffer,
3452 			  unsigned long payload)
3453 {
3454 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3455 	unsigned long flags;
3456 	int ret = -ENOSYS;
3457 
3458 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3459 	switch (base->type) {
3460 	case FW_ISO_CONTEXT_TRANSMIT:
3461 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3462 		break;
3463 	case FW_ISO_CONTEXT_RECEIVE:
3464 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3465 		break;
3466 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3467 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3468 		break;
3469 	}
3470 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3471 
3472 	return ret;
3473 }
3474 
3475 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3476 {
3477 	struct context *ctx =
3478 			&container_of(base, struct iso_context, base)->context;
3479 
3480 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3481 }
3482 
3483 static int ohci_flush_iso_completions(struct fw_iso_context *base)
3484 {
3485 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3486 	int ret = 0;
3487 
3488 	tasklet_disable(&ctx->context.tasklet);
3489 
3490 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
3491 		context_tasklet((unsigned long)&ctx->context);
3492 
3493 		switch (base->type) {
3494 		case FW_ISO_CONTEXT_TRANSMIT:
3495 		case FW_ISO_CONTEXT_RECEIVE:
3496 			if (ctx->header_length != 0)
3497 				flush_iso_completions(ctx);
3498 			break;
3499 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3500 			if (ctx->mc_completed != 0)
3501 				flush_ir_buffer_fill(ctx);
3502 			break;
3503 		default:
3504 			ret = -ENOSYS;
3505 		}
3506 
3507 		clear_bit_unlock(0, &ctx->flushing_completions);
3508 		smp_mb__after_atomic();
3509 	}
3510 
3511 	tasklet_enable(&ctx->context.tasklet);
3512 
3513 	return ret;
3514 }
3515 
3516 static const struct fw_card_driver ohci_driver = {
3517 	.enable			= ohci_enable,
3518 	.read_phy_reg		= ohci_read_phy_reg,
3519 	.update_phy_reg		= ohci_update_phy_reg,
3520 	.set_config_rom		= ohci_set_config_rom,
3521 	.send_request		= ohci_send_request,
3522 	.send_response		= ohci_send_response,
3523 	.cancel_packet		= ohci_cancel_packet,
3524 	.enable_phys_dma	= ohci_enable_phys_dma,
3525 	.read_csr		= ohci_read_csr,
3526 	.write_csr		= ohci_write_csr,
3527 
3528 	.allocate_iso_context	= ohci_allocate_iso_context,
3529 	.free_iso_context	= ohci_free_iso_context,
3530 	.set_iso_channels	= ohci_set_iso_channels,
3531 	.queue_iso		= ohci_queue_iso,
3532 	.flush_queue_iso	= ohci_flush_queue_iso,
3533 	.flush_iso_completions	= ohci_flush_iso_completions,
3534 	.start_iso		= ohci_start_iso,
3535 	.stop_iso		= ohci_stop_iso,
3536 };
3537 
3538 #ifdef CONFIG_PPC_PMAC
3539 static void pmac_ohci_on(struct pci_dev *dev)
3540 {
3541 	if (machine_is(powermac)) {
3542 		struct device_node *ofn = pci_device_to_OF_node(dev);
3543 
3544 		if (ofn) {
3545 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3546 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3547 		}
3548 	}
3549 }
3550 
3551 static void pmac_ohci_off(struct pci_dev *dev)
3552 {
3553 	if (machine_is(powermac)) {
3554 		struct device_node *ofn = pci_device_to_OF_node(dev);
3555 
3556 		if (ofn) {
3557 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3558 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3559 		}
3560 	}
3561 }
3562 #else
3563 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3564 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3565 #endif /* CONFIG_PPC_PMAC */
3566 
3567 static int pci_probe(struct pci_dev *dev,
3568 			       const struct pci_device_id *ent)
3569 {
3570 	struct fw_ohci *ohci;
3571 	u32 bus_options, max_receive, link_speed, version;
3572 	u64 guid;
3573 	int i, err;
3574 	size_t size;
3575 
3576 	if (dev->vendor == PCI_VENDOR_ID_PINNACLE_SYSTEMS) {
3577 		dev_err(&dev->dev, "Pinnacle MovieBoard is not yet supported\n");
3578 		return -ENOSYS;
3579 	}
3580 
3581 	ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3582 	if (ohci == NULL) {
3583 		err = -ENOMEM;
3584 		goto fail;
3585 	}
3586 
3587 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3588 
3589 	pmac_ohci_on(dev);
3590 
3591 	err = pci_enable_device(dev);
3592 	if (err) {
3593 		dev_err(&dev->dev, "failed to enable OHCI hardware\n");
3594 		goto fail_free;
3595 	}
3596 
3597 	pci_set_master(dev);
3598 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3599 	pci_set_drvdata(dev, ohci);
3600 
3601 	spin_lock_init(&ohci->lock);
3602 	mutex_init(&ohci->phy_reg_mutex);
3603 
3604 	INIT_WORK(&ohci->bus_reset_work, bus_reset_work);
3605 
3606 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM) ||
3607 	    pci_resource_len(dev, 0) < OHCI1394_REGISTER_SIZE) {
3608 		ohci_err(ohci, "invalid MMIO resource\n");
3609 		err = -ENXIO;
3610 		goto fail_disable;
3611 	}
3612 
3613 	err = pci_request_region(dev, 0, ohci_driver_name);
3614 	if (err) {
3615 		ohci_err(ohci, "MMIO resource unavailable\n");
3616 		goto fail_disable;
3617 	}
3618 
3619 	ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3620 	if (ohci->registers == NULL) {
3621 		ohci_err(ohci, "failed to remap registers\n");
3622 		err = -ENXIO;
3623 		goto fail_iomem;
3624 	}
3625 
3626 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3627 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3628 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3629 		     ohci_quirks[i].device == dev->device) &&
3630 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3631 		     ohci_quirks[i].revision >= dev->revision)) {
3632 			ohci->quirks = ohci_quirks[i].flags;
3633 			break;
3634 		}
3635 	if (param_quirks)
3636 		ohci->quirks = param_quirks;
3637 
3638 	/*
3639 	 * Because dma_alloc_coherent() allocates at least one page,
3640 	 * we save space by using a common buffer for the AR request/
3641 	 * response descriptors and the self IDs buffer.
3642 	 */
3643 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3644 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3645 	ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3646 					       PAGE_SIZE,
3647 					       &ohci->misc_buffer_bus,
3648 					       GFP_KERNEL);
3649 	if (!ohci->misc_buffer) {
3650 		err = -ENOMEM;
3651 		goto fail_iounmap;
3652 	}
3653 
3654 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3655 			      OHCI1394_AsReqRcvContextControlSet);
3656 	if (err < 0)
3657 		goto fail_misc_buf;
3658 
3659 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3660 			      OHCI1394_AsRspRcvContextControlSet);
3661 	if (err < 0)
3662 		goto fail_arreq_ctx;
3663 
3664 	err = context_init(&ohci->at_request_ctx, ohci,
3665 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3666 	if (err < 0)
3667 		goto fail_arrsp_ctx;
3668 
3669 	err = context_init(&ohci->at_response_ctx, ohci,
3670 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3671 	if (err < 0)
3672 		goto fail_atreq_ctx;
3673 
3674 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3675 	ohci->ir_context_channels = ~0ULL;
3676 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3677 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3678 	ohci->ir_context_mask = ohci->ir_context_support;
3679 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3680 	size = sizeof(struct iso_context) * ohci->n_ir;
3681 	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3682 
3683 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3684 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3685 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3686 	ohci->it_context_mask = ohci->it_context_support;
3687 	ohci->n_it = hweight32(ohci->it_context_mask);
3688 	size = sizeof(struct iso_context) * ohci->n_it;
3689 	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3690 
3691 	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3692 		err = -ENOMEM;
3693 		goto fail_contexts;
3694 	}
3695 
3696 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
3697 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3698 
3699 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3700 	max_receive = (bus_options >> 12) & 0xf;
3701 	link_speed = bus_options & 0x7;
3702 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3703 		reg_read(ohci, OHCI1394_GUIDLo);
3704 
3705 	if (!(ohci->quirks & QUIRK_NO_MSI))
3706 		pci_enable_msi(dev);
3707 	if (request_irq(dev->irq, irq_handler,
3708 			pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
3709 			ohci_driver_name, ohci)) {
3710 		ohci_err(ohci, "failed to allocate interrupt %d\n", dev->irq);
3711 		err = -EIO;
3712 		goto fail_msi;
3713 	}
3714 
3715 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3716 	if (err)
3717 		goto fail_irq;
3718 
3719 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3720 	ohci_notice(ohci,
3721 		    "added OHCI v%x.%x device as card %d, "
3722 		    "%d IR + %d IT contexts, quirks 0x%x%s\n",
3723 		    version >> 16, version & 0xff, ohci->card.index,
3724 		    ohci->n_ir, ohci->n_it, ohci->quirks,
3725 		    reg_read(ohci, OHCI1394_PhyUpperBound) ?
3726 			", physUB" : "");
3727 
3728 	return 0;
3729 
3730  fail_irq:
3731 	free_irq(dev->irq, ohci);
3732  fail_msi:
3733 	pci_disable_msi(dev);
3734  fail_contexts:
3735 	kfree(ohci->ir_context_list);
3736 	kfree(ohci->it_context_list);
3737 	context_release(&ohci->at_response_ctx);
3738  fail_atreq_ctx:
3739 	context_release(&ohci->at_request_ctx);
3740  fail_arrsp_ctx:
3741 	ar_context_release(&ohci->ar_response_ctx);
3742  fail_arreq_ctx:
3743 	ar_context_release(&ohci->ar_request_ctx);
3744  fail_misc_buf:
3745 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3746 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3747  fail_iounmap:
3748 	pci_iounmap(dev, ohci->registers);
3749  fail_iomem:
3750 	pci_release_region(dev, 0);
3751  fail_disable:
3752 	pci_disable_device(dev);
3753  fail_free:
3754 	kfree(ohci);
3755 	pmac_ohci_off(dev);
3756  fail:
3757 	return err;
3758 }
3759 
3760 static void pci_remove(struct pci_dev *dev)
3761 {
3762 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3763 
3764 	/*
3765 	 * If the removal is happening from the suspend state, LPS won't be
3766 	 * enabled and host registers (eg., IntMaskClear) won't be accessible.
3767 	 */
3768 	if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) {
3769 		reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3770 		flush_writes(ohci);
3771 	}
3772 	cancel_work_sync(&ohci->bus_reset_work);
3773 	fw_core_remove_card(&ohci->card);
3774 
3775 	/*
3776 	 * FIXME: Fail all pending packets here, now that the upper
3777 	 * layers can't queue any more.
3778 	 */
3779 
3780 	software_reset(ohci);
3781 	free_irq(dev->irq, ohci);
3782 
3783 	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3784 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3785 				  ohci->next_config_rom, ohci->next_config_rom_bus);
3786 	if (ohci->config_rom)
3787 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3788 				  ohci->config_rom, ohci->config_rom_bus);
3789 	ar_context_release(&ohci->ar_request_ctx);
3790 	ar_context_release(&ohci->ar_response_ctx);
3791 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3792 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3793 	context_release(&ohci->at_request_ctx);
3794 	context_release(&ohci->at_response_ctx);
3795 	kfree(ohci->it_context_list);
3796 	kfree(ohci->ir_context_list);
3797 	pci_disable_msi(dev);
3798 	pci_iounmap(dev, ohci->registers);
3799 	pci_release_region(dev, 0);
3800 	pci_disable_device(dev);
3801 	kfree(ohci);
3802 	pmac_ohci_off(dev);
3803 
3804 	dev_notice(&dev->dev, "removed fw-ohci device\n");
3805 }
3806 
3807 #ifdef CONFIG_PM
3808 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3809 {
3810 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3811 	int err;
3812 
3813 	software_reset(ohci);
3814 	err = pci_save_state(dev);
3815 	if (err) {
3816 		ohci_err(ohci, "pci_save_state failed\n");
3817 		return err;
3818 	}
3819 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3820 	if (err)
3821 		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
3822 	pmac_ohci_off(dev);
3823 
3824 	return 0;
3825 }
3826 
3827 static int pci_resume(struct pci_dev *dev)
3828 {
3829 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3830 	int err;
3831 
3832 	pmac_ohci_on(dev);
3833 	pci_set_power_state(dev, PCI_D0);
3834 	pci_restore_state(dev);
3835 	err = pci_enable_device(dev);
3836 	if (err) {
3837 		ohci_err(ohci, "pci_enable_device failed\n");
3838 		return err;
3839 	}
3840 
3841 	/* Some systems don't setup GUID register on resume from ram  */
3842 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3843 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3844 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3845 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3846 	}
3847 
3848 	err = ohci_enable(&ohci->card, NULL, 0);
3849 	if (err)
3850 		return err;
3851 
3852 	ohci_resume_iso_dma(ohci);
3853 
3854 	return 0;
3855 }
3856 #endif
3857 
3858 static const struct pci_device_id pci_table[] = {
3859 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3860 	{ }
3861 };
3862 
3863 MODULE_DEVICE_TABLE(pci, pci_table);
3864 
3865 static struct pci_driver fw_ohci_pci_driver = {
3866 	.name		= ohci_driver_name,
3867 	.id_table	= pci_table,
3868 	.probe		= pci_probe,
3869 	.remove		= pci_remove,
3870 #ifdef CONFIG_PM
3871 	.resume		= pci_resume,
3872 	.suspend	= pci_suspend,
3873 #endif
3874 };
3875 
3876 static int __init fw_ohci_init(void)
3877 {
3878 	selfid_workqueue = alloc_workqueue(KBUILD_MODNAME, WQ_MEM_RECLAIM, 0);
3879 	if (!selfid_workqueue)
3880 		return -ENOMEM;
3881 
3882 	return pci_register_driver(&fw_ohci_pci_driver);
3883 }
3884 
3885 static void __exit fw_ohci_cleanup(void)
3886 {
3887 	pci_unregister_driver(&fw_ohci_pci_driver);
3888 	destroy_workqueue(selfid_workqueue);
3889 }
3890 
3891 module_init(fw_ohci_init);
3892 module_exit(fw_ohci_cleanup);
3893 
3894 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3895 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3896 MODULE_LICENSE("GPL");
3897 
3898 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3899 MODULE_ALIAS("ohci1394");
3900