xref: /linux/drivers/firewire/ohci.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
1 /*
2  * Driver for OHCI 1394 controllers
3  *
4  * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 #include <linux/bitops.h>
22 #include <linux/bug.h>
23 #include <linux/compiler.h>
24 #include <linux/delay.h>
25 #include <linux/device.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/firewire.h>
28 #include <linux/firewire-constants.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/io.h>
32 #include <linux/kernel.h>
33 #include <linux/list.h>
34 #include <linux/mm.h>
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/mutex.h>
38 #include <linux/pci.h>
39 #include <linux/pci_ids.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/string.h>
43 #include <linux/time.h>
44 #include <linux/vmalloc.h>
45 #include <linux/workqueue.h>
46 
47 #include <asm/byteorder.h>
48 #include <asm/page.h>
49 
50 #ifdef CONFIG_PPC_PMAC
51 #include <asm/pmac_feature.h>
52 #endif
53 
54 #include "core.h"
55 #include "ohci.h"
56 
57 #define ohci_info(ohci, f, args...)	dev_info(ohci->card.device, f, ##args)
58 #define ohci_notice(ohci, f, args...)	dev_notice(ohci->card.device, f, ##args)
59 #define ohci_err(ohci, f, args...)	dev_err(ohci->card.device, f, ##args)
60 
61 #define DESCRIPTOR_OUTPUT_MORE		0
62 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
63 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
64 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
65 #define DESCRIPTOR_STATUS		(1 << 11)
66 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
67 #define DESCRIPTOR_PING			(1 << 7)
68 #define DESCRIPTOR_YY			(1 << 6)
69 #define DESCRIPTOR_NO_IRQ		(0 << 4)
70 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
71 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
72 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
73 #define DESCRIPTOR_WAIT			(3 << 0)
74 
75 #define DESCRIPTOR_CMD			(0xf << 12)
76 
77 struct descriptor {
78 	__le16 req_count;
79 	__le16 control;
80 	__le32 data_address;
81 	__le32 branch_address;
82 	__le16 res_count;
83 	__le16 transfer_status;
84 } __attribute__((aligned(16)));
85 
86 #define CONTROL_SET(regs)	(regs)
87 #define CONTROL_CLEAR(regs)	((regs) + 4)
88 #define COMMAND_PTR(regs)	((regs) + 12)
89 #define CONTEXT_MATCH(regs)	((regs) + 16)
90 
91 #define AR_BUFFER_SIZE	(32*1024)
92 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
93 /* we need at least two pages for proper list management */
94 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
95 
96 #define MAX_ASYNC_PAYLOAD	4096
97 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
98 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
99 
100 struct ar_context {
101 	struct fw_ohci *ohci;
102 	struct page *pages[AR_BUFFERS];
103 	void *buffer;
104 	struct descriptor *descriptors;
105 	dma_addr_t descriptors_bus;
106 	void *pointer;
107 	unsigned int last_buffer_index;
108 	u32 regs;
109 	struct tasklet_struct tasklet;
110 };
111 
112 struct context;
113 
114 typedef int (*descriptor_callback_t)(struct context *ctx,
115 				     struct descriptor *d,
116 				     struct descriptor *last);
117 
118 /*
119  * A buffer that contains a block of DMA-able coherent memory used for
120  * storing a portion of a DMA descriptor program.
121  */
122 struct descriptor_buffer {
123 	struct list_head list;
124 	dma_addr_t buffer_bus;
125 	size_t buffer_size;
126 	size_t used;
127 	struct descriptor buffer[0];
128 };
129 
130 struct context {
131 	struct fw_ohci *ohci;
132 	u32 regs;
133 	int total_allocation;
134 	u32 current_bus;
135 	bool running;
136 	bool flushing;
137 
138 	/*
139 	 * List of page-sized buffers for storing DMA descriptors.
140 	 * Head of list contains buffers in use and tail of list contains
141 	 * free buffers.
142 	 */
143 	struct list_head buffer_list;
144 
145 	/*
146 	 * Pointer to a buffer inside buffer_list that contains the tail
147 	 * end of the current DMA program.
148 	 */
149 	struct descriptor_buffer *buffer_tail;
150 
151 	/*
152 	 * The descriptor containing the branch address of the first
153 	 * descriptor that has not yet been filled by the device.
154 	 */
155 	struct descriptor *last;
156 
157 	/*
158 	 * The last descriptor block in the DMA program. It contains the branch
159 	 * address that must be updated upon appending a new descriptor.
160 	 */
161 	struct descriptor *prev;
162 	int prev_z;
163 
164 	descriptor_callback_t callback;
165 
166 	struct tasklet_struct tasklet;
167 };
168 
169 #define IT_HEADER_SY(v)          ((v) <<  0)
170 #define IT_HEADER_TCODE(v)       ((v) <<  4)
171 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
172 #define IT_HEADER_TAG(v)         ((v) << 14)
173 #define IT_HEADER_SPEED(v)       ((v) << 16)
174 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
175 
176 struct iso_context {
177 	struct fw_iso_context base;
178 	struct context context;
179 	void *header;
180 	size_t header_length;
181 	unsigned long flushing_completions;
182 	u32 mc_buffer_bus;
183 	u16 mc_completed;
184 	u16 last_timestamp;
185 	u8 sync;
186 	u8 tags;
187 };
188 
189 #define CONFIG_ROM_SIZE 1024
190 
191 struct fw_ohci {
192 	struct fw_card card;
193 
194 	__iomem char *registers;
195 	int node_id;
196 	int generation;
197 	int request_generation;	/* for timestamping incoming requests */
198 	unsigned quirks;
199 	unsigned int pri_req_max;
200 	u32 bus_time;
201 	bool bus_time_running;
202 	bool is_root;
203 	bool csr_state_setclear_abdicate;
204 	int n_ir;
205 	int n_it;
206 	/*
207 	 * Spinlock for accessing fw_ohci data.  Never call out of
208 	 * this driver with this lock held.
209 	 */
210 	spinlock_t lock;
211 
212 	struct mutex phy_reg_mutex;
213 
214 	void *misc_buffer;
215 	dma_addr_t misc_buffer_bus;
216 
217 	struct ar_context ar_request_ctx;
218 	struct ar_context ar_response_ctx;
219 	struct context at_request_ctx;
220 	struct context at_response_ctx;
221 
222 	u32 it_context_support;
223 	u32 it_context_mask;     /* unoccupied IT contexts */
224 	struct iso_context *it_context_list;
225 	u64 ir_context_channels; /* unoccupied channels */
226 	u32 ir_context_support;
227 	u32 ir_context_mask;     /* unoccupied IR contexts */
228 	struct iso_context *ir_context_list;
229 	u64 mc_channels; /* channels in use by the multichannel IR context */
230 	bool mc_allocated;
231 
232 	__be32    *config_rom;
233 	dma_addr_t config_rom_bus;
234 	__be32    *next_config_rom;
235 	dma_addr_t next_config_rom_bus;
236 	__be32     next_header;
237 
238 	__le32    *self_id;
239 	dma_addr_t self_id_bus;
240 	struct work_struct bus_reset_work;
241 
242 	u32 self_id_buffer[512];
243 };
244 
245 static struct workqueue_struct *selfid_workqueue;
246 
247 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
248 {
249 	return container_of(card, struct fw_ohci, card);
250 }
251 
252 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
253 #define IR_CONTEXT_BUFFER_FILL		0x80000000
254 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
255 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
256 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
257 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
258 
259 #define CONTEXT_RUN	0x8000
260 #define CONTEXT_WAKE	0x1000
261 #define CONTEXT_DEAD	0x0800
262 #define CONTEXT_ACTIVE	0x0400
263 
264 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
265 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
266 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
267 
268 #define OHCI1394_REGISTER_SIZE		0x800
269 #define OHCI1394_PCI_HCI_Control	0x40
270 #define SELF_ID_BUF_SIZE		0x800
271 #define OHCI_TCODE_PHY_PACKET		0x0e
272 #define OHCI_VERSION_1_1		0x010010
273 
274 static char ohci_driver_name[] = KBUILD_MODNAME;
275 
276 #define PCI_VENDOR_ID_PINNACLE_SYSTEMS	0x11bd
277 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
278 #define PCI_DEVICE_ID_CREATIVE_SB1394	0x4001
279 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
280 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
281 #define PCI_DEVICE_ID_TI_TSB12LV26	0x8020
282 #define PCI_DEVICE_ID_TI_TSB82AA2	0x8025
283 #define PCI_DEVICE_ID_VIA_VT630X	0x3044
284 #define PCI_REV_ID_VIA_VT6306		0x46
285 #define PCI_DEVICE_ID_VIA_VT6315	0x3403
286 
287 #define QUIRK_CYCLE_TIMER		0x1
288 #define QUIRK_RESET_PACKET		0x2
289 #define QUIRK_BE_HEADERS		0x4
290 #define QUIRK_NO_1394A			0x8
291 #define QUIRK_NO_MSI			0x10
292 #define QUIRK_TI_SLLZ059		0x20
293 #define QUIRK_IR_WAKE			0x40
294 
295 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
296 static const struct {
297 	unsigned short vendor, device, revision, flags;
298 } ohci_quirks[] = {
299 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
300 		QUIRK_CYCLE_TIMER},
301 
302 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
303 		QUIRK_BE_HEADERS},
304 
305 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
306 		QUIRK_NO_MSI},
307 
308 	{PCI_VENDOR_ID_CREATIVE, PCI_DEVICE_ID_CREATIVE_SB1394, PCI_ANY_ID,
309 		QUIRK_RESET_PACKET},
310 
311 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
312 		QUIRK_NO_MSI},
313 
314 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
315 		QUIRK_CYCLE_TIMER},
316 
317 	{PCI_VENDOR_ID_O2, PCI_ANY_ID, PCI_ANY_ID,
318 		QUIRK_NO_MSI},
319 
320 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
321 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
322 
323 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
324 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
325 
326 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV26, PCI_ANY_ID,
327 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
328 
329 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB82AA2, PCI_ANY_ID,
330 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
331 
332 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
333 		QUIRK_RESET_PACKET},
334 
335 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT630X, PCI_REV_ID_VIA_VT6306,
336 		QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE},
337 
338 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, 0,
339 		QUIRK_CYCLE_TIMER /* FIXME: necessary? */ | QUIRK_NO_MSI},
340 
341 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT6315, PCI_ANY_ID,
342 		QUIRK_NO_MSI},
343 
344 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
345 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
346 };
347 
348 /* This overrides anything that was found in ohci_quirks[]. */
349 static int param_quirks;
350 module_param_named(quirks, param_quirks, int, 0644);
351 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
352 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
353 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
354 	", AR/selfID endianness = "	__stringify(QUIRK_BE_HEADERS)
355 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
356 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
357 	", TI SLLZ059 erratum = "	__stringify(QUIRK_TI_SLLZ059)
358 	", IR wake unreliable = "	__stringify(QUIRK_IR_WAKE)
359 	")");
360 
361 #define OHCI_PARAM_DEBUG_AT_AR		1
362 #define OHCI_PARAM_DEBUG_SELFIDS	2
363 #define OHCI_PARAM_DEBUG_IRQS		4
364 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
365 
366 static int param_debug;
367 module_param_named(debug, param_debug, int, 0644);
368 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
369 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
370 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
371 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
372 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
373 	", or a combination, or all = -1)");
374 
375 static bool param_remote_dma;
376 module_param_named(remote_dma, param_remote_dma, bool, 0444);
377 MODULE_PARM_DESC(remote_dma, "Enable unfiltered remote DMA (default = N)");
378 
379 static void log_irqs(struct fw_ohci *ohci, u32 evt)
380 {
381 	if (likely(!(param_debug &
382 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
383 		return;
384 
385 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
386 	    !(evt & OHCI1394_busReset))
387 		return;
388 
389 	ohci_notice(ohci, "IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
390 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
391 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
392 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
393 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
394 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
395 	    evt & OHCI1394_isochRx		? " IR"			: "",
396 	    evt & OHCI1394_isochTx		? " IT"			: "",
397 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
398 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
399 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
400 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
401 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
402 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
403 	    evt & OHCI1394_busReset		? " busReset"		: "",
404 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
405 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
406 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
407 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
408 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
409 		    OHCI1394_cycleInconsistent |
410 		    OHCI1394_regAccessFail | OHCI1394_busReset)
411 						? " ?"			: "");
412 }
413 
414 static const char *speed[] = {
415 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
416 };
417 static const char *power[] = {
418 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
419 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
420 };
421 static const char port[] = { '.', '-', 'p', 'c', };
422 
423 static char _p(u32 *s, int shift)
424 {
425 	return port[*s >> shift & 3];
426 }
427 
428 static void log_selfids(struct fw_ohci *ohci, int generation, int self_id_count)
429 {
430 	u32 *s;
431 
432 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
433 		return;
434 
435 	ohci_notice(ohci, "%d selfIDs, generation %d, local node ID %04x\n",
436 		    self_id_count, generation, ohci->node_id);
437 
438 	for (s = ohci->self_id_buffer; self_id_count--; ++s)
439 		if ((*s & 1 << 23) == 0)
440 			ohci_notice(ohci,
441 			    "selfID 0: %08x, phy %d [%c%c%c] %s gc=%d %s %s%s%s\n",
442 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
443 			    speed[*s >> 14 & 3], *s >> 16 & 63,
444 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
445 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
446 		else
447 			ohci_notice(ohci,
448 			    "selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
449 			    *s, *s >> 24 & 63,
450 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
451 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
452 }
453 
454 static const char *evts[] = {
455 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
456 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
457 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
458 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
459 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
460 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
461 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
462 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
463 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
464 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
465 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
466 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
467 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
468 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
469 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
470 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
471 	[0x20] = "pending/cancelled",
472 };
473 static const char *tcodes[] = {
474 	[0x0] = "QW req",		[0x1] = "BW req",
475 	[0x2] = "W resp",		[0x3] = "-reserved-",
476 	[0x4] = "QR req",		[0x5] = "BR req",
477 	[0x6] = "QR resp",		[0x7] = "BR resp",
478 	[0x8] = "cycle start",		[0x9] = "Lk req",
479 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
480 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
481 	[0xe] = "link internal",	[0xf] = "-reserved-",
482 };
483 
484 static void log_ar_at_event(struct fw_ohci *ohci,
485 			    char dir, int speed, u32 *header, int evt)
486 {
487 	int tcode = header[0] >> 4 & 0xf;
488 	char specific[12];
489 
490 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
491 		return;
492 
493 	if (unlikely(evt >= ARRAY_SIZE(evts)))
494 			evt = 0x1f;
495 
496 	if (evt == OHCI1394_evt_bus_reset) {
497 		ohci_notice(ohci, "A%c evt_bus_reset, generation %d\n",
498 			    dir, (header[2] >> 16) & 0xff);
499 		return;
500 	}
501 
502 	switch (tcode) {
503 	case 0x0: case 0x6: case 0x8:
504 		snprintf(specific, sizeof(specific), " = %08x",
505 			 be32_to_cpu((__force __be32)header[3]));
506 		break;
507 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
508 		snprintf(specific, sizeof(specific), " %x,%x",
509 			 header[3] >> 16, header[3] & 0xffff);
510 		break;
511 	default:
512 		specific[0] = '\0';
513 	}
514 
515 	switch (tcode) {
516 	case 0xa:
517 		ohci_notice(ohci, "A%c %s, %s\n",
518 			    dir, evts[evt], tcodes[tcode]);
519 		break;
520 	case 0xe:
521 		ohci_notice(ohci, "A%c %s, PHY %08x %08x\n",
522 			    dir, evts[evt], header[1], header[2]);
523 		break;
524 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
525 		ohci_notice(ohci,
526 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s, %04x%08x%s\n",
527 			    dir, speed, header[0] >> 10 & 0x3f,
528 			    header[1] >> 16, header[0] >> 16, evts[evt],
529 			    tcodes[tcode], header[1] & 0xffff, header[2], specific);
530 		break;
531 	default:
532 		ohci_notice(ohci,
533 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s%s\n",
534 			    dir, speed, header[0] >> 10 & 0x3f,
535 			    header[1] >> 16, header[0] >> 16, evts[evt],
536 			    tcodes[tcode], specific);
537 	}
538 }
539 
540 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
541 {
542 	writel(data, ohci->registers + offset);
543 }
544 
545 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
546 {
547 	return readl(ohci->registers + offset);
548 }
549 
550 static inline void flush_writes(const struct fw_ohci *ohci)
551 {
552 	/* Do a dummy read to flush writes. */
553 	reg_read(ohci, OHCI1394_Version);
554 }
555 
556 /*
557  * Beware!  read_phy_reg(), write_phy_reg(), update_phy_reg(), and
558  * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
559  * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
560  * directly.  Exceptions are intrinsically serialized contexts like pci_probe.
561  */
562 static int read_phy_reg(struct fw_ohci *ohci, int addr)
563 {
564 	u32 val;
565 	int i;
566 
567 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
568 	for (i = 0; i < 3 + 100; i++) {
569 		val = reg_read(ohci, OHCI1394_PhyControl);
570 		if (!~val)
571 			return -ENODEV; /* Card was ejected. */
572 
573 		if (val & OHCI1394_PhyControl_ReadDone)
574 			return OHCI1394_PhyControl_ReadData(val);
575 
576 		/*
577 		 * Try a few times without waiting.  Sleeping is necessary
578 		 * only when the link/PHY interface is busy.
579 		 */
580 		if (i >= 3)
581 			msleep(1);
582 	}
583 	ohci_err(ohci, "failed to read phy reg %d\n", addr);
584 	dump_stack();
585 
586 	return -EBUSY;
587 }
588 
589 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
590 {
591 	int i;
592 
593 	reg_write(ohci, OHCI1394_PhyControl,
594 		  OHCI1394_PhyControl_Write(addr, val));
595 	for (i = 0; i < 3 + 100; i++) {
596 		val = reg_read(ohci, OHCI1394_PhyControl);
597 		if (!~val)
598 			return -ENODEV; /* Card was ejected. */
599 
600 		if (!(val & OHCI1394_PhyControl_WritePending))
601 			return 0;
602 
603 		if (i >= 3)
604 			msleep(1);
605 	}
606 	ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
607 	dump_stack();
608 
609 	return -EBUSY;
610 }
611 
612 static int update_phy_reg(struct fw_ohci *ohci, int addr,
613 			  int clear_bits, int set_bits)
614 {
615 	int ret = read_phy_reg(ohci, addr);
616 	if (ret < 0)
617 		return ret;
618 
619 	/*
620 	 * The interrupt status bits are cleared by writing a one bit.
621 	 * Avoid clearing them unless explicitly requested in set_bits.
622 	 */
623 	if (addr == 5)
624 		clear_bits |= PHY_INT_STATUS_BITS;
625 
626 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
627 }
628 
629 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
630 {
631 	int ret;
632 
633 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
634 	if (ret < 0)
635 		return ret;
636 
637 	return read_phy_reg(ohci, addr);
638 }
639 
640 static int ohci_read_phy_reg(struct fw_card *card, int addr)
641 {
642 	struct fw_ohci *ohci = fw_ohci(card);
643 	int ret;
644 
645 	mutex_lock(&ohci->phy_reg_mutex);
646 	ret = read_phy_reg(ohci, addr);
647 	mutex_unlock(&ohci->phy_reg_mutex);
648 
649 	return ret;
650 }
651 
652 static int ohci_update_phy_reg(struct fw_card *card, int addr,
653 			       int clear_bits, int set_bits)
654 {
655 	struct fw_ohci *ohci = fw_ohci(card);
656 	int ret;
657 
658 	mutex_lock(&ohci->phy_reg_mutex);
659 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
660 	mutex_unlock(&ohci->phy_reg_mutex);
661 
662 	return ret;
663 }
664 
665 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
666 {
667 	return page_private(ctx->pages[i]);
668 }
669 
670 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
671 {
672 	struct descriptor *d;
673 
674 	d = &ctx->descriptors[index];
675 	d->branch_address  &= cpu_to_le32(~0xf);
676 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
677 	d->transfer_status =  0;
678 
679 	wmb(); /* finish init of new descriptors before branch_address update */
680 	d = &ctx->descriptors[ctx->last_buffer_index];
681 	d->branch_address  |= cpu_to_le32(1);
682 
683 	ctx->last_buffer_index = index;
684 
685 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
686 }
687 
688 static void ar_context_release(struct ar_context *ctx)
689 {
690 	unsigned int i;
691 
692 	vunmap(ctx->buffer);
693 
694 	for (i = 0; i < AR_BUFFERS; i++)
695 		if (ctx->pages[i]) {
696 			dma_unmap_page(ctx->ohci->card.device,
697 				       ar_buffer_bus(ctx, i),
698 				       PAGE_SIZE, DMA_FROM_DEVICE);
699 			__free_page(ctx->pages[i]);
700 		}
701 }
702 
703 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
704 {
705 	struct fw_ohci *ohci = ctx->ohci;
706 
707 	if (reg_read(ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
708 		reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
709 		flush_writes(ohci);
710 
711 		ohci_err(ohci, "AR error: %s; DMA stopped\n", error_msg);
712 	}
713 	/* FIXME: restart? */
714 }
715 
716 static inline unsigned int ar_next_buffer_index(unsigned int index)
717 {
718 	return (index + 1) % AR_BUFFERS;
719 }
720 
721 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
722 {
723 	return ar_next_buffer_index(ctx->last_buffer_index);
724 }
725 
726 /*
727  * We search for the buffer that contains the last AR packet DMA data written
728  * by the controller.
729  */
730 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
731 						 unsigned int *buffer_offset)
732 {
733 	unsigned int i, next_i, last = ctx->last_buffer_index;
734 	__le16 res_count, next_res_count;
735 
736 	i = ar_first_buffer_index(ctx);
737 	res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
738 
739 	/* A buffer that is not yet completely filled must be the last one. */
740 	while (i != last && res_count == 0) {
741 
742 		/* Peek at the next descriptor. */
743 		next_i = ar_next_buffer_index(i);
744 		rmb(); /* read descriptors in order */
745 		next_res_count = ACCESS_ONCE(
746 				ctx->descriptors[next_i].res_count);
747 		/*
748 		 * If the next descriptor is still empty, we must stop at this
749 		 * descriptor.
750 		 */
751 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
752 			/*
753 			 * The exception is when the DMA data for one packet is
754 			 * split over three buffers; in this case, the middle
755 			 * buffer's descriptor might be never updated by the
756 			 * controller and look still empty, and we have to peek
757 			 * at the third one.
758 			 */
759 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
760 				next_i = ar_next_buffer_index(next_i);
761 				rmb();
762 				next_res_count = ACCESS_ONCE(
763 					ctx->descriptors[next_i].res_count);
764 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
765 					goto next_buffer_is_active;
766 			}
767 
768 			break;
769 		}
770 
771 next_buffer_is_active:
772 		i = next_i;
773 		res_count = next_res_count;
774 	}
775 
776 	rmb(); /* read res_count before the DMA data */
777 
778 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
779 	if (*buffer_offset > PAGE_SIZE) {
780 		*buffer_offset = 0;
781 		ar_context_abort(ctx, "corrupted descriptor");
782 	}
783 
784 	return i;
785 }
786 
787 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
788 				    unsigned int end_buffer_index,
789 				    unsigned int end_buffer_offset)
790 {
791 	unsigned int i;
792 
793 	i = ar_first_buffer_index(ctx);
794 	while (i != end_buffer_index) {
795 		dma_sync_single_for_cpu(ctx->ohci->card.device,
796 					ar_buffer_bus(ctx, i),
797 					PAGE_SIZE, DMA_FROM_DEVICE);
798 		i = ar_next_buffer_index(i);
799 	}
800 	if (end_buffer_offset > 0)
801 		dma_sync_single_for_cpu(ctx->ohci->card.device,
802 					ar_buffer_bus(ctx, i),
803 					end_buffer_offset, DMA_FROM_DEVICE);
804 }
805 
806 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
807 #define cond_le32_to_cpu(v) \
808 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
809 #else
810 #define cond_le32_to_cpu(v) le32_to_cpu(v)
811 #endif
812 
813 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
814 {
815 	struct fw_ohci *ohci = ctx->ohci;
816 	struct fw_packet p;
817 	u32 status, length, tcode;
818 	int evt;
819 
820 	p.header[0] = cond_le32_to_cpu(buffer[0]);
821 	p.header[1] = cond_le32_to_cpu(buffer[1]);
822 	p.header[2] = cond_le32_to_cpu(buffer[2]);
823 
824 	tcode = (p.header[0] >> 4) & 0x0f;
825 	switch (tcode) {
826 	case TCODE_WRITE_QUADLET_REQUEST:
827 	case TCODE_READ_QUADLET_RESPONSE:
828 		p.header[3] = (__force __u32) buffer[3];
829 		p.header_length = 16;
830 		p.payload_length = 0;
831 		break;
832 
833 	case TCODE_READ_BLOCK_REQUEST :
834 		p.header[3] = cond_le32_to_cpu(buffer[3]);
835 		p.header_length = 16;
836 		p.payload_length = 0;
837 		break;
838 
839 	case TCODE_WRITE_BLOCK_REQUEST:
840 	case TCODE_READ_BLOCK_RESPONSE:
841 	case TCODE_LOCK_REQUEST:
842 	case TCODE_LOCK_RESPONSE:
843 		p.header[3] = cond_le32_to_cpu(buffer[3]);
844 		p.header_length = 16;
845 		p.payload_length = p.header[3] >> 16;
846 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
847 			ar_context_abort(ctx, "invalid packet length");
848 			return NULL;
849 		}
850 		break;
851 
852 	case TCODE_WRITE_RESPONSE:
853 	case TCODE_READ_QUADLET_REQUEST:
854 	case OHCI_TCODE_PHY_PACKET:
855 		p.header_length = 12;
856 		p.payload_length = 0;
857 		break;
858 
859 	default:
860 		ar_context_abort(ctx, "invalid tcode");
861 		return NULL;
862 	}
863 
864 	p.payload = (void *) buffer + p.header_length;
865 
866 	/* FIXME: What to do about evt_* errors? */
867 	length = (p.header_length + p.payload_length + 3) / 4;
868 	status = cond_le32_to_cpu(buffer[length]);
869 	evt    = (status >> 16) & 0x1f;
870 
871 	p.ack        = evt - 16;
872 	p.speed      = (status >> 21) & 0x7;
873 	p.timestamp  = status & 0xffff;
874 	p.generation = ohci->request_generation;
875 
876 	log_ar_at_event(ohci, 'R', p.speed, p.header, evt);
877 
878 	/*
879 	 * Several controllers, notably from NEC and VIA, forget to
880 	 * write ack_complete status at PHY packet reception.
881 	 */
882 	if (evt == OHCI1394_evt_no_status &&
883 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
884 		p.ack = ACK_COMPLETE;
885 
886 	/*
887 	 * The OHCI bus reset handler synthesizes a PHY packet with
888 	 * the new generation number when a bus reset happens (see
889 	 * section 8.4.2.3).  This helps us determine when a request
890 	 * was received and make sure we send the response in the same
891 	 * generation.  We only need this for requests; for responses
892 	 * we use the unique tlabel for finding the matching
893 	 * request.
894 	 *
895 	 * Alas some chips sometimes emit bus reset packets with a
896 	 * wrong generation.  We set the correct generation for these
897 	 * at a slightly incorrect time (in bus_reset_work).
898 	 */
899 	if (evt == OHCI1394_evt_bus_reset) {
900 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
901 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
902 	} else if (ctx == &ohci->ar_request_ctx) {
903 		fw_core_handle_request(&ohci->card, &p);
904 	} else {
905 		fw_core_handle_response(&ohci->card, &p);
906 	}
907 
908 	return buffer + length + 1;
909 }
910 
911 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
912 {
913 	void *next;
914 
915 	while (p < end) {
916 		next = handle_ar_packet(ctx, p);
917 		if (!next)
918 			return p;
919 		p = next;
920 	}
921 
922 	return p;
923 }
924 
925 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
926 {
927 	unsigned int i;
928 
929 	i = ar_first_buffer_index(ctx);
930 	while (i != end_buffer) {
931 		dma_sync_single_for_device(ctx->ohci->card.device,
932 					   ar_buffer_bus(ctx, i),
933 					   PAGE_SIZE, DMA_FROM_DEVICE);
934 		ar_context_link_page(ctx, i);
935 		i = ar_next_buffer_index(i);
936 	}
937 }
938 
939 static void ar_context_tasklet(unsigned long data)
940 {
941 	struct ar_context *ctx = (struct ar_context *)data;
942 	unsigned int end_buffer_index, end_buffer_offset;
943 	void *p, *end;
944 
945 	p = ctx->pointer;
946 	if (!p)
947 		return;
948 
949 	end_buffer_index = ar_search_last_active_buffer(ctx,
950 							&end_buffer_offset);
951 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
952 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
953 
954 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
955 		/*
956 		 * The filled part of the overall buffer wraps around; handle
957 		 * all packets up to the buffer end here.  If the last packet
958 		 * wraps around, its tail will be visible after the buffer end
959 		 * because the buffer start pages are mapped there again.
960 		 */
961 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
962 		p = handle_ar_packets(ctx, p, buffer_end);
963 		if (p < buffer_end)
964 			goto error;
965 		/* adjust p to point back into the actual buffer */
966 		p -= AR_BUFFERS * PAGE_SIZE;
967 	}
968 
969 	p = handle_ar_packets(ctx, p, end);
970 	if (p != end) {
971 		if (p > end)
972 			ar_context_abort(ctx, "inconsistent descriptor");
973 		goto error;
974 	}
975 
976 	ctx->pointer = p;
977 	ar_recycle_buffers(ctx, end_buffer_index);
978 
979 	return;
980 
981 error:
982 	ctx->pointer = NULL;
983 }
984 
985 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
986 			   unsigned int descriptors_offset, u32 regs)
987 {
988 	unsigned int i;
989 	dma_addr_t dma_addr;
990 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
991 	struct descriptor *d;
992 
993 	ctx->regs        = regs;
994 	ctx->ohci        = ohci;
995 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
996 
997 	for (i = 0; i < AR_BUFFERS; i++) {
998 		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
999 		if (!ctx->pages[i])
1000 			goto out_of_memory;
1001 		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
1002 					0, PAGE_SIZE, DMA_FROM_DEVICE);
1003 		if (dma_mapping_error(ohci->card.device, dma_addr)) {
1004 			__free_page(ctx->pages[i]);
1005 			ctx->pages[i] = NULL;
1006 			goto out_of_memory;
1007 		}
1008 		set_page_private(ctx->pages[i], dma_addr);
1009 	}
1010 
1011 	for (i = 0; i < AR_BUFFERS; i++)
1012 		pages[i]              = ctx->pages[i];
1013 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
1014 		pages[AR_BUFFERS + i] = ctx->pages[i];
1015 	ctx->buffer = vmap(pages, ARRAY_SIZE(pages), VM_MAP, PAGE_KERNEL);
1016 	if (!ctx->buffer)
1017 		goto out_of_memory;
1018 
1019 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
1020 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
1021 
1022 	for (i = 0; i < AR_BUFFERS; i++) {
1023 		d = &ctx->descriptors[i];
1024 		d->req_count      = cpu_to_le16(PAGE_SIZE);
1025 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
1026 						DESCRIPTOR_STATUS |
1027 						DESCRIPTOR_BRANCH_ALWAYS);
1028 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
1029 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
1030 			ar_next_buffer_index(i) * sizeof(struct descriptor));
1031 	}
1032 
1033 	return 0;
1034 
1035 out_of_memory:
1036 	ar_context_release(ctx);
1037 
1038 	return -ENOMEM;
1039 }
1040 
1041 static void ar_context_run(struct ar_context *ctx)
1042 {
1043 	unsigned int i;
1044 
1045 	for (i = 0; i < AR_BUFFERS; i++)
1046 		ar_context_link_page(ctx, i);
1047 
1048 	ctx->pointer = ctx->buffer;
1049 
1050 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1051 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1052 }
1053 
1054 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1055 {
1056 	__le16 branch;
1057 
1058 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1059 
1060 	/* figure out which descriptor the branch address goes in */
1061 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1062 		return d;
1063 	else
1064 		return d + z - 1;
1065 }
1066 
1067 static void context_tasklet(unsigned long data)
1068 {
1069 	struct context *ctx = (struct context *) data;
1070 	struct descriptor *d, *last;
1071 	u32 address;
1072 	int z;
1073 	struct descriptor_buffer *desc;
1074 
1075 	desc = list_entry(ctx->buffer_list.next,
1076 			struct descriptor_buffer, list);
1077 	last = ctx->last;
1078 	while (last->branch_address != 0) {
1079 		struct descriptor_buffer *old_desc = desc;
1080 		address = le32_to_cpu(last->branch_address);
1081 		z = address & 0xf;
1082 		address &= ~0xf;
1083 		ctx->current_bus = address;
1084 
1085 		/* If the branch address points to a buffer outside of the
1086 		 * current buffer, advance to the next buffer. */
1087 		if (address < desc->buffer_bus ||
1088 				address >= desc->buffer_bus + desc->used)
1089 			desc = list_entry(desc->list.next,
1090 					struct descriptor_buffer, list);
1091 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1092 		last = find_branch_descriptor(d, z);
1093 
1094 		if (!ctx->callback(ctx, d, last))
1095 			break;
1096 
1097 		if (old_desc != desc) {
1098 			/* If we've advanced to the next buffer, move the
1099 			 * previous buffer to the free list. */
1100 			unsigned long flags;
1101 			old_desc->used = 0;
1102 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1103 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1104 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1105 		}
1106 		ctx->last = last;
1107 	}
1108 }
1109 
1110 /*
1111  * Allocate a new buffer and add it to the list of free buffers for this
1112  * context.  Must be called with ohci->lock held.
1113  */
1114 static int context_add_buffer(struct context *ctx)
1115 {
1116 	struct descriptor_buffer *desc;
1117 	dma_addr_t uninitialized_var(bus_addr);
1118 	int offset;
1119 
1120 	/*
1121 	 * 16MB of descriptors should be far more than enough for any DMA
1122 	 * program.  This will catch run-away userspace or DoS attacks.
1123 	 */
1124 	if (ctx->total_allocation >= 16*1024*1024)
1125 		return -ENOMEM;
1126 
1127 	desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1128 			&bus_addr, GFP_ATOMIC);
1129 	if (!desc)
1130 		return -ENOMEM;
1131 
1132 	offset = (void *)&desc->buffer - (void *)desc;
1133 	desc->buffer_size = PAGE_SIZE - offset;
1134 	desc->buffer_bus = bus_addr + offset;
1135 	desc->used = 0;
1136 
1137 	list_add_tail(&desc->list, &ctx->buffer_list);
1138 	ctx->total_allocation += PAGE_SIZE;
1139 
1140 	return 0;
1141 }
1142 
1143 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1144 			u32 regs, descriptor_callback_t callback)
1145 {
1146 	ctx->ohci = ohci;
1147 	ctx->regs = regs;
1148 	ctx->total_allocation = 0;
1149 
1150 	INIT_LIST_HEAD(&ctx->buffer_list);
1151 	if (context_add_buffer(ctx) < 0)
1152 		return -ENOMEM;
1153 
1154 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1155 			struct descriptor_buffer, list);
1156 
1157 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1158 	ctx->callback = callback;
1159 
1160 	/*
1161 	 * We put a dummy descriptor in the buffer that has a NULL
1162 	 * branch address and looks like it's been sent.  That way we
1163 	 * have a descriptor to append DMA programs to.
1164 	 */
1165 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1166 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1167 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1168 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1169 	ctx->last = ctx->buffer_tail->buffer;
1170 	ctx->prev = ctx->buffer_tail->buffer;
1171 	ctx->prev_z = 1;
1172 
1173 	return 0;
1174 }
1175 
1176 static void context_release(struct context *ctx)
1177 {
1178 	struct fw_card *card = &ctx->ohci->card;
1179 	struct descriptor_buffer *desc, *tmp;
1180 
1181 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1182 		dma_free_coherent(card->device, PAGE_SIZE, desc,
1183 			desc->buffer_bus -
1184 			((void *)&desc->buffer - (void *)desc));
1185 }
1186 
1187 /* Must be called with ohci->lock held */
1188 static struct descriptor *context_get_descriptors(struct context *ctx,
1189 						  int z, dma_addr_t *d_bus)
1190 {
1191 	struct descriptor *d = NULL;
1192 	struct descriptor_buffer *desc = ctx->buffer_tail;
1193 
1194 	if (z * sizeof(*d) > desc->buffer_size)
1195 		return NULL;
1196 
1197 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1198 		/* No room for the descriptor in this buffer, so advance to the
1199 		 * next one. */
1200 
1201 		if (desc->list.next == &ctx->buffer_list) {
1202 			/* If there is no free buffer next in the list,
1203 			 * allocate one. */
1204 			if (context_add_buffer(ctx) < 0)
1205 				return NULL;
1206 		}
1207 		desc = list_entry(desc->list.next,
1208 				struct descriptor_buffer, list);
1209 		ctx->buffer_tail = desc;
1210 	}
1211 
1212 	d = desc->buffer + desc->used / sizeof(*d);
1213 	memset(d, 0, z * sizeof(*d));
1214 	*d_bus = desc->buffer_bus + desc->used;
1215 
1216 	return d;
1217 }
1218 
1219 static void context_run(struct context *ctx, u32 extra)
1220 {
1221 	struct fw_ohci *ohci = ctx->ohci;
1222 
1223 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1224 		  le32_to_cpu(ctx->last->branch_address));
1225 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1226 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1227 	ctx->running = true;
1228 	flush_writes(ohci);
1229 }
1230 
1231 static void context_append(struct context *ctx,
1232 			   struct descriptor *d, int z, int extra)
1233 {
1234 	dma_addr_t d_bus;
1235 	struct descriptor_buffer *desc = ctx->buffer_tail;
1236 	struct descriptor *d_branch;
1237 
1238 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1239 
1240 	desc->used += (z + extra) * sizeof(*d);
1241 
1242 	wmb(); /* finish init of new descriptors before branch_address update */
1243 
1244 	d_branch = find_branch_descriptor(ctx->prev, ctx->prev_z);
1245 	d_branch->branch_address = cpu_to_le32(d_bus | z);
1246 
1247 	/*
1248 	 * VT6306 incorrectly checks only the single descriptor at the
1249 	 * CommandPtr when the wake bit is written, so if it's a
1250 	 * multi-descriptor block starting with an INPUT_MORE, put a copy of
1251 	 * the branch address in the first descriptor.
1252 	 *
1253 	 * Not doing this for transmit contexts since not sure how it interacts
1254 	 * with skip addresses.
1255 	 */
1256 	if (unlikely(ctx->ohci->quirks & QUIRK_IR_WAKE) &&
1257 	    d_branch != ctx->prev &&
1258 	    (ctx->prev->control & cpu_to_le16(DESCRIPTOR_CMD)) ==
1259 	     cpu_to_le16(DESCRIPTOR_INPUT_MORE)) {
1260 		ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1261 	}
1262 
1263 	ctx->prev = d;
1264 	ctx->prev_z = z;
1265 }
1266 
1267 static void context_stop(struct context *ctx)
1268 {
1269 	struct fw_ohci *ohci = ctx->ohci;
1270 	u32 reg;
1271 	int i;
1272 
1273 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1274 	ctx->running = false;
1275 
1276 	for (i = 0; i < 1000; i++) {
1277 		reg = reg_read(ohci, CONTROL_SET(ctx->regs));
1278 		if ((reg & CONTEXT_ACTIVE) == 0)
1279 			return;
1280 
1281 		if (i)
1282 			udelay(10);
1283 	}
1284 	ohci_err(ohci, "DMA context still active (0x%08x)\n", reg);
1285 }
1286 
1287 struct driver_data {
1288 	u8 inline_data[8];
1289 	struct fw_packet *packet;
1290 };
1291 
1292 /*
1293  * This function apppends a packet to the DMA queue for transmission.
1294  * Must always be called with the ochi->lock held to ensure proper
1295  * generation handling and locking around packet queue manipulation.
1296  */
1297 static int at_context_queue_packet(struct context *ctx,
1298 				   struct fw_packet *packet)
1299 {
1300 	struct fw_ohci *ohci = ctx->ohci;
1301 	dma_addr_t d_bus, uninitialized_var(payload_bus);
1302 	struct driver_data *driver_data;
1303 	struct descriptor *d, *last;
1304 	__le32 *header;
1305 	int z, tcode;
1306 
1307 	d = context_get_descriptors(ctx, 4, &d_bus);
1308 	if (d == NULL) {
1309 		packet->ack = RCODE_SEND_ERROR;
1310 		return -1;
1311 	}
1312 
1313 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1314 	d[0].res_count = cpu_to_le16(packet->timestamp);
1315 
1316 	/*
1317 	 * The DMA format for asynchronous link packets is different
1318 	 * from the IEEE1394 layout, so shift the fields around
1319 	 * accordingly.
1320 	 */
1321 
1322 	tcode = (packet->header[0] >> 4) & 0x0f;
1323 	header = (__le32 *) &d[1];
1324 	switch (tcode) {
1325 	case TCODE_WRITE_QUADLET_REQUEST:
1326 	case TCODE_WRITE_BLOCK_REQUEST:
1327 	case TCODE_WRITE_RESPONSE:
1328 	case TCODE_READ_QUADLET_REQUEST:
1329 	case TCODE_READ_BLOCK_REQUEST:
1330 	case TCODE_READ_QUADLET_RESPONSE:
1331 	case TCODE_READ_BLOCK_RESPONSE:
1332 	case TCODE_LOCK_REQUEST:
1333 	case TCODE_LOCK_RESPONSE:
1334 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1335 					(packet->speed << 16));
1336 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1337 					(packet->header[0] & 0xffff0000));
1338 		header[2] = cpu_to_le32(packet->header[2]);
1339 
1340 		if (TCODE_IS_BLOCK_PACKET(tcode))
1341 			header[3] = cpu_to_le32(packet->header[3]);
1342 		else
1343 			header[3] = (__force __le32) packet->header[3];
1344 
1345 		d[0].req_count = cpu_to_le16(packet->header_length);
1346 		break;
1347 
1348 	case TCODE_LINK_INTERNAL:
1349 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1350 					(packet->speed << 16));
1351 		header[1] = cpu_to_le32(packet->header[1]);
1352 		header[2] = cpu_to_le32(packet->header[2]);
1353 		d[0].req_count = cpu_to_le16(12);
1354 
1355 		if (is_ping_packet(&packet->header[1]))
1356 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1357 		break;
1358 
1359 	case TCODE_STREAM_DATA:
1360 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1361 					(packet->speed << 16));
1362 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1363 		d[0].req_count = cpu_to_le16(8);
1364 		break;
1365 
1366 	default:
1367 		/* BUG(); */
1368 		packet->ack = RCODE_SEND_ERROR;
1369 		return -1;
1370 	}
1371 
1372 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1373 	driver_data = (struct driver_data *) &d[3];
1374 	driver_data->packet = packet;
1375 	packet->driver_data = driver_data;
1376 
1377 	if (packet->payload_length > 0) {
1378 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1379 			payload_bus = dma_map_single(ohci->card.device,
1380 						     packet->payload,
1381 						     packet->payload_length,
1382 						     DMA_TO_DEVICE);
1383 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1384 				packet->ack = RCODE_SEND_ERROR;
1385 				return -1;
1386 			}
1387 			packet->payload_bus	= payload_bus;
1388 			packet->payload_mapped	= true;
1389 		} else {
1390 			memcpy(driver_data->inline_data, packet->payload,
1391 			       packet->payload_length);
1392 			payload_bus = d_bus + 3 * sizeof(*d);
1393 		}
1394 
1395 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1396 		d[2].data_address = cpu_to_le32(payload_bus);
1397 		last = &d[2];
1398 		z = 3;
1399 	} else {
1400 		last = &d[0];
1401 		z = 2;
1402 	}
1403 
1404 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1405 				     DESCRIPTOR_IRQ_ALWAYS |
1406 				     DESCRIPTOR_BRANCH_ALWAYS);
1407 
1408 	/* FIXME: Document how the locking works. */
1409 	if (ohci->generation != packet->generation) {
1410 		if (packet->payload_mapped)
1411 			dma_unmap_single(ohci->card.device, payload_bus,
1412 					 packet->payload_length, DMA_TO_DEVICE);
1413 		packet->ack = RCODE_GENERATION;
1414 		return -1;
1415 	}
1416 
1417 	context_append(ctx, d, z, 4 - z);
1418 
1419 	if (ctx->running)
1420 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1421 	else
1422 		context_run(ctx, 0);
1423 
1424 	return 0;
1425 }
1426 
1427 static void at_context_flush(struct context *ctx)
1428 {
1429 	tasklet_disable(&ctx->tasklet);
1430 
1431 	ctx->flushing = true;
1432 	context_tasklet((unsigned long)ctx);
1433 	ctx->flushing = false;
1434 
1435 	tasklet_enable(&ctx->tasklet);
1436 }
1437 
1438 static int handle_at_packet(struct context *context,
1439 			    struct descriptor *d,
1440 			    struct descriptor *last)
1441 {
1442 	struct driver_data *driver_data;
1443 	struct fw_packet *packet;
1444 	struct fw_ohci *ohci = context->ohci;
1445 	int evt;
1446 
1447 	if (last->transfer_status == 0 && !context->flushing)
1448 		/* This descriptor isn't done yet, stop iteration. */
1449 		return 0;
1450 
1451 	driver_data = (struct driver_data *) &d[3];
1452 	packet = driver_data->packet;
1453 	if (packet == NULL)
1454 		/* This packet was cancelled, just continue. */
1455 		return 1;
1456 
1457 	if (packet->payload_mapped)
1458 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1459 				 packet->payload_length, DMA_TO_DEVICE);
1460 
1461 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1462 	packet->timestamp = le16_to_cpu(last->res_count);
1463 
1464 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, evt);
1465 
1466 	switch (evt) {
1467 	case OHCI1394_evt_timeout:
1468 		/* Async response transmit timed out. */
1469 		packet->ack = RCODE_CANCELLED;
1470 		break;
1471 
1472 	case OHCI1394_evt_flushed:
1473 		/*
1474 		 * The packet was flushed should give same error as
1475 		 * when we try to use a stale generation count.
1476 		 */
1477 		packet->ack = RCODE_GENERATION;
1478 		break;
1479 
1480 	case OHCI1394_evt_missing_ack:
1481 		if (context->flushing)
1482 			packet->ack = RCODE_GENERATION;
1483 		else {
1484 			/*
1485 			 * Using a valid (current) generation count, but the
1486 			 * node is not on the bus or not sending acks.
1487 			 */
1488 			packet->ack = RCODE_NO_ACK;
1489 		}
1490 		break;
1491 
1492 	case ACK_COMPLETE + 0x10:
1493 	case ACK_PENDING + 0x10:
1494 	case ACK_BUSY_X + 0x10:
1495 	case ACK_BUSY_A + 0x10:
1496 	case ACK_BUSY_B + 0x10:
1497 	case ACK_DATA_ERROR + 0x10:
1498 	case ACK_TYPE_ERROR + 0x10:
1499 		packet->ack = evt - 0x10;
1500 		break;
1501 
1502 	case OHCI1394_evt_no_status:
1503 		if (context->flushing) {
1504 			packet->ack = RCODE_GENERATION;
1505 			break;
1506 		}
1507 		/* fall through */
1508 
1509 	default:
1510 		packet->ack = RCODE_SEND_ERROR;
1511 		break;
1512 	}
1513 
1514 	packet->callback(packet, &ohci->card, packet->ack);
1515 
1516 	return 1;
1517 }
1518 
1519 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1520 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1521 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1522 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1523 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
1524 
1525 static void handle_local_rom(struct fw_ohci *ohci,
1526 			     struct fw_packet *packet, u32 csr)
1527 {
1528 	struct fw_packet response;
1529 	int tcode, length, i;
1530 
1531 	tcode = HEADER_GET_TCODE(packet->header[0]);
1532 	if (TCODE_IS_BLOCK_PACKET(tcode))
1533 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1534 	else
1535 		length = 4;
1536 
1537 	i = csr - CSR_CONFIG_ROM;
1538 	if (i + length > CONFIG_ROM_SIZE) {
1539 		fw_fill_response(&response, packet->header,
1540 				 RCODE_ADDRESS_ERROR, NULL, 0);
1541 	} else if (!TCODE_IS_READ_REQUEST(tcode)) {
1542 		fw_fill_response(&response, packet->header,
1543 				 RCODE_TYPE_ERROR, NULL, 0);
1544 	} else {
1545 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1546 				 (void *) ohci->config_rom + i, length);
1547 	}
1548 
1549 	fw_core_handle_response(&ohci->card, &response);
1550 }
1551 
1552 static void handle_local_lock(struct fw_ohci *ohci,
1553 			      struct fw_packet *packet, u32 csr)
1554 {
1555 	struct fw_packet response;
1556 	int tcode, length, ext_tcode, sel, try;
1557 	__be32 *payload, lock_old;
1558 	u32 lock_arg, lock_data;
1559 
1560 	tcode = HEADER_GET_TCODE(packet->header[0]);
1561 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1562 	payload = packet->payload;
1563 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1564 
1565 	if (tcode == TCODE_LOCK_REQUEST &&
1566 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1567 		lock_arg = be32_to_cpu(payload[0]);
1568 		lock_data = be32_to_cpu(payload[1]);
1569 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1570 		lock_arg = 0;
1571 		lock_data = 0;
1572 	} else {
1573 		fw_fill_response(&response, packet->header,
1574 				 RCODE_TYPE_ERROR, NULL, 0);
1575 		goto out;
1576 	}
1577 
1578 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1579 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1580 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1581 	reg_write(ohci, OHCI1394_CSRControl, sel);
1582 
1583 	for (try = 0; try < 20; try++)
1584 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1585 			lock_old = cpu_to_be32(reg_read(ohci,
1586 							OHCI1394_CSRData));
1587 			fw_fill_response(&response, packet->header,
1588 					 RCODE_COMPLETE,
1589 					 &lock_old, sizeof(lock_old));
1590 			goto out;
1591 		}
1592 
1593 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
1594 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1595 
1596  out:
1597 	fw_core_handle_response(&ohci->card, &response);
1598 }
1599 
1600 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1601 {
1602 	u64 offset, csr;
1603 
1604 	if (ctx == &ctx->ohci->at_request_ctx) {
1605 		packet->ack = ACK_PENDING;
1606 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1607 	}
1608 
1609 	offset =
1610 		((unsigned long long)
1611 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1612 		packet->header[2];
1613 	csr = offset - CSR_REGISTER_BASE;
1614 
1615 	/* Handle config rom reads. */
1616 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1617 		handle_local_rom(ctx->ohci, packet, csr);
1618 	else switch (csr) {
1619 	case CSR_BUS_MANAGER_ID:
1620 	case CSR_BANDWIDTH_AVAILABLE:
1621 	case CSR_CHANNELS_AVAILABLE_HI:
1622 	case CSR_CHANNELS_AVAILABLE_LO:
1623 		handle_local_lock(ctx->ohci, packet, csr);
1624 		break;
1625 	default:
1626 		if (ctx == &ctx->ohci->at_request_ctx)
1627 			fw_core_handle_request(&ctx->ohci->card, packet);
1628 		else
1629 			fw_core_handle_response(&ctx->ohci->card, packet);
1630 		break;
1631 	}
1632 
1633 	if (ctx == &ctx->ohci->at_response_ctx) {
1634 		packet->ack = ACK_COMPLETE;
1635 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1636 	}
1637 }
1638 
1639 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1640 {
1641 	unsigned long flags;
1642 	int ret;
1643 
1644 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1645 
1646 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1647 	    ctx->ohci->generation == packet->generation) {
1648 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1649 		handle_local_request(ctx, packet);
1650 		return;
1651 	}
1652 
1653 	ret = at_context_queue_packet(ctx, packet);
1654 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1655 
1656 	if (ret < 0)
1657 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1658 
1659 }
1660 
1661 static void detect_dead_context(struct fw_ohci *ohci,
1662 				const char *name, unsigned int regs)
1663 {
1664 	u32 ctl;
1665 
1666 	ctl = reg_read(ohci, CONTROL_SET(regs));
1667 	if (ctl & CONTEXT_DEAD)
1668 		ohci_err(ohci, "DMA context %s has stopped, error code: %s\n",
1669 			name, evts[ctl & 0x1f]);
1670 }
1671 
1672 static void handle_dead_contexts(struct fw_ohci *ohci)
1673 {
1674 	unsigned int i;
1675 	char name[8];
1676 
1677 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1678 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1679 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1680 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1681 	for (i = 0; i < 32; ++i) {
1682 		if (!(ohci->it_context_support & (1 << i)))
1683 			continue;
1684 		sprintf(name, "IT%u", i);
1685 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1686 	}
1687 	for (i = 0; i < 32; ++i) {
1688 		if (!(ohci->ir_context_support & (1 << i)))
1689 			continue;
1690 		sprintf(name, "IR%u", i);
1691 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1692 	}
1693 	/* TODO: maybe try to flush and restart the dead contexts */
1694 }
1695 
1696 static u32 cycle_timer_ticks(u32 cycle_timer)
1697 {
1698 	u32 ticks;
1699 
1700 	ticks = cycle_timer & 0xfff;
1701 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1702 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1703 
1704 	return ticks;
1705 }
1706 
1707 /*
1708  * Some controllers exhibit one or more of the following bugs when updating the
1709  * iso cycle timer register:
1710  *  - When the lowest six bits are wrapping around to zero, a read that happens
1711  *    at the same time will return garbage in the lowest ten bits.
1712  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1713  *    not incremented for about 60 ns.
1714  *  - Occasionally, the entire register reads zero.
1715  *
1716  * To catch these, we read the register three times and ensure that the
1717  * difference between each two consecutive reads is approximately the same, i.e.
1718  * less than twice the other.  Furthermore, any negative difference indicates an
1719  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1720  * execute, so we have enough precision to compute the ratio of the differences.)
1721  */
1722 static u32 get_cycle_time(struct fw_ohci *ohci)
1723 {
1724 	u32 c0, c1, c2;
1725 	u32 t0, t1, t2;
1726 	s32 diff01, diff12;
1727 	int i;
1728 
1729 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1730 
1731 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1732 		i = 0;
1733 		c1 = c2;
1734 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1735 		do {
1736 			c0 = c1;
1737 			c1 = c2;
1738 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1739 			t0 = cycle_timer_ticks(c0);
1740 			t1 = cycle_timer_ticks(c1);
1741 			t2 = cycle_timer_ticks(c2);
1742 			diff01 = t1 - t0;
1743 			diff12 = t2 - t1;
1744 		} while ((diff01 <= 0 || diff12 <= 0 ||
1745 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1746 			 && i++ < 20);
1747 	}
1748 
1749 	return c2;
1750 }
1751 
1752 /*
1753  * This function has to be called at least every 64 seconds.  The bus_time
1754  * field stores not only the upper 25 bits of the BUS_TIME register but also
1755  * the most significant bit of the cycle timer in bit 6 so that we can detect
1756  * changes in this bit.
1757  */
1758 static u32 update_bus_time(struct fw_ohci *ohci)
1759 {
1760 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1761 
1762 	if (unlikely(!ohci->bus_time_running)) {
1763 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds);
1764 		ohci->bus_time = (lower_32_bits(get_seconds()) & ~0x7f) |
1765 		                 (cycle_time_seconds & 0x40);
1766 		ohci->bus_time_running = true;
1767 	}
1768 
1769 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1770 		ohci->bus_time += 0x40;
1771 
1772 	return ohci->bus_time | cycle_time_seconds;
1773 }
1774 
1775 static int get_status_for_port(struct fw_ohci *ohci, int port_index)
1776 {
1777 	int reg;
1778 
1779 	mutex_lock(&ohci->phy_reg_mutex);
1780 	reg = write_phy_reg(ohci, 7, port_index);
1781 	if (reg >= 0)
1782 		reg = read_phy_reg(ohci, 8);
1783 	mutex_unlock(&ohci->phy_reg_mutex);
1784 	if (reg < 0)
1785 		return reg;
1786 
1787 	switch (reg & 0x0f) {
1788 	case 0x06:
1789 		return 2;	/* is child node (connected to parent node) */
1790 	case 0x0e:
1791 		return 3;	/* is parent node (connected to child node) */
1792 	}
1793 	return 1;		/* not connected */
1794 }
1795 
1796 static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
1797 	int self_id_count)
1798 {
1799 	int i;
1800 	u32 entry;
1801 
1802 	for (i = 0; i < self_id_count; i++) {
1803 		entry = ohci->self_id_buffer[i];
1804 		if ((self_id & 0xff000000) == (entry & 0xff000000))
1805 			return -1;
1806 		if ((self_id & 0xff000000) < (entry & 0xff000000))
1807 			return i;
1808 	}
1809 	return i;
1810 }
1811 
1812 static int initiated_reset(struct fw_ohci *ohci)
1813 {
1814 	int reg;
1815 	int ret = 0;
1816 
1817 	mutex_lock(&ohci->phy_reg_mutex);
1818 	reg = write_phy_reg(ohci, 7, 0xe0); /* Select page 7 */
1819 	if (reg >= 0) {
1820 		reg = read_phy_reg(ohci, 8);
1821 		reg |= 0x40;
1822 		reg = write_phy_reg(ohci, 8, reg); /* set PMODE bit */
1823 		if (reg >= 0) {
1824 			reg = read_phy_reg(ohci, 12); /* read register 12 */
1825 			if (reg >= 0) {
1826 				if ((reg & 0x08) == 0x08) {
1827 					/* bit 3 indicates "initiated reset" */
1828 					ret = 0x2;
1829 				}
1830 			}
1831 		}
1832 	}
1833 	mutex_unlock(&ohci->phy_reg_mutex);
1834 	return ret;
1835 }
1836 
1837 /*
1838  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
1839  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
1840  * Construct the selfID from phy register contents.
1841  */
1842 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
1843 {
1844 	int reg, i, pos, status;
1845 	/* link active 1, speed 3, bridge 0, contender 1, more packets 0 */
1846 	u32 self_id = 0x8040c800;
1847 
1848 	reg = reg_read(ohci, OHCI1394_NodeID);
1849 	if (!(reg & OHCI1394_NodeID_idValid)) {
1850 		ohci_notice(ohci,
1851 			    "node ID not valid, new bus reset in progress\n");
1852 		return -EBUSY;
1853 	}
1854 	self_id |= ((reg & 0x3f) << 24); /* phy ID */
1855 
1856 	reg = ohci_read_phy_reg(&ohci->card, 4);
1857 	if (reg < 0)
1858 		return reg;
1859 	self_id |= ((reg & 0x07) << 8); /* power class */
1860 
1861 	reg = ohci_read_phy_reg(&ohci->card, 1);
1862 	if (reg < 0)
1863 		return reg;
1864 	self_id |= ((reg & 0x3f) << 16); /* gap count */
1865 
1866 	for (i = 0; i < 3; i++) {
1867 		status = get_status_for_port(ohci, i);
1868 		if (status < 0)
1869 			return status;
1870 		self_id |= ((status & 0x3) << (6 - (i * 2)));
1871 	}
1872 
1873 	self_id |= initiated_reset(ohci);
1874 
1875 	pos = get_self_id_pos(ohci, self_id, self_id_count);
1876 	if (pos >= 0) {
1877 		memmove(&(ohci->self_id_buffer[pos+1]),
1878 			&(ohci->self_id_buffer[pos]),
1879 			(self_id_count - pos) * sizeof(*ohci->self_id_buffer));
1880 		ohci->self_id_buffer[pos] = self_id;
1881 		self_id_count++;
1882 	}
1883 	return self_id_count;
1884 }
1885 
1886 static void bus_reset_work(struct work_struct *work)
1887 {
1888 	struct fw_ohci *ohci =
1889 		container_of(work, struct fw_ohci, bus_reset_work);
1890 	int self_id_count, generation, new_generation, i, j;
1891 	u32 reg;
1892 	void *free_rom = NULL;
1893 	dma_addr_t free_rom_bus = 0;
1894 	bool is_new_root;
1895 
1896 	reg = reg_read(ohci, OHCI1394_NodeID);
1897 	if (!(reg & OHCI1394_NodeID_idValid)) {
1898 		ohci_notice(ohci,
1899 			    "node ID not valid, new bus reset in progress\n");
1900 		return;
1901 	}
1902 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1903 		ohci_notice(ohci, "malconfigured bus\n");
1904 		return;
1905 	}
1906 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1907 			       OHCI1394_NodeID_nodeNumber);
1908 
1909 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1910 	if (!(ohci->is_root && is_new_root))
1911 		reg_write(ohci, OHCI1394_LinkControlSet,
1912 			  OHCI1394_LinkControl_cycleMaster);
1913 	ohci->is_root = is_new_root;
1914 
1915 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1916 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1917 		ohci_notice(ohci, "self ID receive error\n");
1918 		return;
1919 	}
1920 	/*
1921 	 * The count in the SelfIDCount register is the number of
1922 	 * bytes in the self ID receive buffer.  Since we also receive
1923 	 * the inverted quadlets and a header quadlet, we shift one
1924 	 * bit extra to get the actual number of self IDs.
1925 	 */
1926 	self_id_count = (reg >> 3) & 0xff;
1927 
1928 	if (self_id_count > 252) {
1929 		ohci_notice(ohci, "bad selfIDSize (%08x)\n", reg);
1930 		return;
1931 	}
1932 
1933 	generation = (cond_le32_to_cpu(ohci->self_id[0]) >> 16) & 0xff;
1934 	rmb();
1935 
1936 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1937 		u32 id  = cond_le32_to_cpu(ohci->self_id[i]);
1938 		u32 id2 = cond_le32_to_cpu(ohci->self_id[i + 1]);
1939 
1940 		if (id != ~id2) {
1941 			/*
1942 			 * If the invalid data looks like a cycle start packet,
1943 			 * it's likely to be the result of the cycle master
1944 			 * having a wrong gap count.  In this case, the self IDs
1945 			 * so far are valid and should be processed so that the
1946 			 * bus manager can then correct the gap count.
1947 			 */
1948 			if (id == 0xffff008f) {
1949 				ohci_notice(ohci, "ignoring spurious self IDs\n");
1950 				self_id_count = j;
1951 				break;
1952 			}
1953 
1954 			ohci_notice(ohci, "bad self ID %d/%d (%08x != ~%08x)\n",
1955 				    j, self_id_count, id, id2);
1956 			return;
1957 		}
1958 		ohci->self_id_buffer[j] = id;
1959 	}
1960 
1961 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
1962 		self_id_count = find_and_insert_self_id(ohci, self_id_count);
1963 		if (self_id_count < 0) {
1964 			ohci_notice(ohci,
1965 				    "could not construct local self ID\n");
1966 			return;
1967 		}
1968 	}
1969 
1970 	if (self_id_count == 0) {
1971 		ohci_notice(ohci, "no self IDs\n");
1972 		return;
1973 	}
1974 	rmb();
1975 
1976 	/*
1977 	 * Check the consistency of the self IDs we just read.  The
1978 	 * problem we face is that a new bus reset can start while we
1979 	 * read out the self IDs from the DMA buffer. If this happens,
1980 	 * the DMA buffer will be overwritten with new self IDs and we
1981 	 * will read out inconsistent data.  The OHCI specification
1982 	 * (section 11.2) recommends a technique similar to
1983 	 * linux/seqlock.h, where we remember the generation of the
1984 	 * self IDs in the buffer before reading them out and compare
1985 	 * it to the current generation after reading them out.  If
1986 	 * the two generations match we know we have a consistent set
1987 	 * of self IDs.
1988 	 */
1989 
1990 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1991 	if (new_generation != generation) {
1992 		ohci_notice(ohci, "new bus reset, discarding self ids\n");
1993 		return;
1994 	}
1995 
1996 	/* FIXME: Document how the locking works. */
1997 	spin_lock_irq(&ohci->lock);
1998 
1999 	ohci->generation = -1; /* prevent AT packet queueing */
2000 	context_stop(&ohci->at_request_ctx);
2001 	context_stop(&ohci->at_response_ctx);
2002 
2003 	spin_unlock_irq(&ohci->lock);
2004 
2005 	/*
2006 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
2007 	 * packets in the AT queues and software needs to drain them.
2008 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
2009 	 */
2010 	at_context_flush(&ohci->at_request_ctx);
2011 	at_context_flush(&ohci->at_response_ctx);
2012 
2013 	spin_lock_irq(&ohci->lock);
2014 
2015 	ohci->generation = generation;
2016 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
2017 
2018 	if (ohci->quirks & QUIRK_RESET_PACKET)
2019 		ohci->request_generation = generation;
2020 
2021 	/*
2022 	 * This next bit is unrelated to the AT context stuff but we
2023 	 * have to do it under the spinlock also.  If a new config rom
2024 	 * was set up before this reset, the old one is now no longer
2025 	 * in use and we can free it. Update the config rom pointers
2026 	 * to point to the current config rom and clear the
2027 	 * next_config_rom pointer so a new update can take place.
2028 	 */
2029 
2030 	if (ohci->next_config_rom != NULL) {
2031 		if (ohci->next_config_rom != ohci->config_rom) {
2032 			free_rom      = ohci->config_rom;
2033 			free_rom_bus  = ohci->config_rom_bus;
2034 		}
2035 		ohci->config_rom      = ohci->next_config_rom;
2036 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
2037 		ohci->next_config_rom = NULL;
2038 
2039 		/*
2040 		 * Restore config_rom image and manually update
2041 		 * config_rom registers.  Writing the header quadlet
2042 		 * will indicate that the config rom is ready, so we
2043 		 * do that last.
2044 		 */
2045 		reg_write(ohci, OHCI1394_BusOptions,
2046 			  be32_to_cpu(ohci->config_rom[2]));
2047 		ohci->config_rom[0] = ohci->next_header;
2048 		reg_write(ohci, OHCI1394_ConfigROMhdr,
2049 			  be32_to_cpu(ohci->next_header));
2050 	}
2051 
2052 	if (param_remote_dma) {
2053 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
2054 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
2055 	}
2056 
2057 	spin_unlock_irq(&ohci->lock);
2058 
2059 	if (free_rom)
2060 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2061 				  free_rom, free_rom_bus);
2062 
2063 	log_selfids(ohci, generation, self_id_count);
2064 
2065 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
2066 				 self_id_count, ohci->self_id_buffer,
2067 				 ohci->csr_state_setclear_abdicate);
2068 	ohci->csr_state_setclear_abdicate = false;
2069 }
2070 
2071 static irqreturn_t irq_handler(int irq, void *data)
2072 {
2073 	struct fw_ohci *ohci = data;
2074 	u32 event, iso_event;
2075 	int i;
2076 
2077 	event = reg_read(ohci, OHCI1394_IntEventClear);
2078 
2079 	if (!event || !~event)
2080 		return IRQ_NONE;
2081 
2082 	/*
2083 	 * busReset and postedWriteErr must not be cleared yet
2084 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
2085 	 */
2086 	reg_write(ohci, OHCI1394_IntEventClear,
2087 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
2088 	log_irqs(ohci, event);
2089 
2090 	if (event & OHCI1394_selfIDComplete)
2091 		queue_work(selfid_workqueue, &ohci->bus_reset_work);
2092 
2093 	if (event & OHCI1394_RQPkt)
2094 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
2095 
2096 	if (event & OHCI1394_RSPkt)
2097 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
2098 
2099 	if (event & OHCI1394_reqTxComplete)
2100 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
2101 
2102 	if (event & OHCI1394_respTxComplete)
2103 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
2104 
2105 	if (event & OHCI1394_isochRx) {
2106 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
2107 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
2108 
2109 		while (iso_event) {
2110 			i = ffs(iso_event) - 1;
2111 			tasklet_schedule(
2112 				&ohci->ir_context_list[i].context.tasklet);
2113 			iso_event &= ~(1 << i);
2114 		}
2115 	}
2116 
2117 	if (event & OHCI1394_isochTx) {
2118 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
2119 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
2120 
2121 		while (iso_event) {
2122 			i = ffs(iso_event) - 1;
2123 			tasklet_schedule(
2124 				&ohci->it_context_list[i].context.tasklet);
2125 			iso_event &= ~(1 << i);
2126 		}
2127 	}
2128 
2129 	if (unlikely(event & OHCI1394_regAccessFail))
2130 		ohci_err(ohci, "register access failure\n");
2131 
2132 	if (unlikely(event & OHCI1394_postedWriteErr)) {
2133 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
2134 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
2135 		reg_write(ohci, OHCI1394_IntEventClear,
2136 			  OHCI1394_postedWriteErr);
2137 		if (printk_ratelimit())
2138 			ohci_err(ohci, "PCI posted write error\n");
2139 	}
2140 
2141 	if (unlikely(event & OHCI1394_cycleTooLong)) {
2142 		if (printk_ratelimit())
2143 			ohci_notice(ohci, "isochronous cycle too long\n");
2144 		reg_write(ohci, OHCI1394_LinkControlSet,
2145 			  OHCI1394_LinkControl_cycleMaster);
2146 	}
2147 
2148 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
2149 		/*
2150 		 * We need to clear this event bit in order to make
2151 		 * cycleMatch isochronous I/O work.  In theory we should
2152 		 * stop active cycleMatch iso contexts now and restart
2153 		 * them at least two cycles later.  (FIXME?)
2154 		 */
2155 		if (printk_ratelimit())
2156 			ohci_notice(ohci, "isochronous cycle inconsistent\n");
2157 	}
2158 
2159 	if (unlikely(event & OHCI1394_unrecoverableError))
2160 		handle_dead_contexts(ohci);
2161 
2162 	if (event & OHCI1394_cycle64Seconds) {
2163 		spin_lock(&ohci->lock);
2164 		update_bus_time(ohci);
2165 		spin_unlock(&ohci->lock);
2166 	} else
2167 		flush_writes(ohci);
2168 
2169 	return IRQ_HANDLED;
2170 }
2171 
2172 static int software_reset(struct fw_ohci *ohci)
2173 {
2174 	u32 val;
2175 	int i;
2176 
2177 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
2178 	for (i = 0; i < 500; i++) {
2179 		val = reg_read(ohci, OHCI1394_HCControlSet);
2180 		if (!~val)
2181 			return -ENODEV; /* Card was ejected. */
2182 
2183 		if (!(val & OHCI1394_HCControl_softReset))
2184 			return 0;
2185 
2186 		msleep(1);
2187 	}
2188 
2189 	return -EBUSY;
2190 }
2191 
2192 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
2193 {
2194 	size_t size = length * 4;
2195 
2196 	memcpy(dest, src, size);
2197 	if (size < CONFIG_ROM_SIZE)
2198 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
2199 }
2200 
2201 static int configure_1394a_enhancements(struct fw_ohci *ohci)
2202 {
2203 	bool enable_1394a;
2204 	int ret, clear, set, offset;
2205 
2206 	/* Check if the driver should configure link and PHY. */
2207 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
2208 	      OHCI1394_HCControl_programPhyEnable))
2209 		return 0;
2210 
2211 	/* Paranoia: check whether the PHY supports 1394a, too. */
2212 	enable_1394a = false;
2213 	ret = read_phy_reg(ohci, 2);
2214 	if (ret < 0)
2215 		return ret;
2216 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2217 		ret = read_paged_phy_reg(ohci, 1, 8);
2218 		if (ret < 0)
2219 			return ret;
2220 		if (ret >= 1)
2221 			enable_1394a = true;
2222 	}
2223 
2224 	if (ohci->quirks & QUIRK_NO_1394A)
2225 		enable_1394a = false;
2226 
2227 	/* Configure PHY and link consistently. */
2228 	if (enable_1394a) {
2229 		clear = 0;
2230 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2231 	} else {
2232 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2233 		set = 0;
2234 	}
2235 	ret = update_phy_reg(ohci, 5, clear, set);
2236 	if (ret < 0)
2237 		return ret;
2238 
2239 	if (enable_1394a)
2240 		offset = OHCI1394_HCControlSet;
2241 	else
2242 		offset = OHCI1394_HCControlClear;
2243 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2244 
2245 	/* Clean up: configuration has been taken care of. */
2246 	reg_write(ohci, OHCI1394_HCControlClear,
2247 		  OHCI1394_HCControl_programPhyEnable);
2248 
2249 	return 0;
2250 }
2251 
2252 static int probe_tsb41ba3d(struct fw_ohci *ohci)
2253 {
2254 	/* TI vendor ID = 0x080028, TSB41BA3D product ID = 0x833005 (sic) */
2255 	static const u8 id[] = { 0x08, 0x00, 0x28, 0x83, 0x30, 0x05, };
2256 	int reg, i;
2257 
2258 	reg = read_phy_reg(ohci, 2);
2259 	if (reg < 0)
2260 		return reg;
2261 	if ((reg & PHY_EXTENDED_REGISTERS) != PHY_EXTENDED_REGISTERS)
2262 		return 0;
2263 
2264 	for (i = ARRAY_SIZE(id) - 1; i >= 0; i--) {
2265 		reg = read_paged_phy_reg(ohci, 1, i + 10);
2266 		if (reg < 0)
2267 			return reg;
2268 		if (reg != id[i])
2269 			return 0;
2270 	}
2271 	return 1;
2272 }
2273 
2274 static int ohci_enable(struct fw_card *card,
2275 		       const __be32 *config_rom, size_t length)
2276 {
2277 	struct fw_ohci *ohci = fw_ohci(card);
2278 	u32 lps, version, irqs;
2279 	int i, ret;
2280 
2281 	if (software_reset(ohci)) {
2282 		ohci_err(ohci, "failed to reset ohci card\n");
2283 		return -EBUSY;
2284 	}
2285 
2286 	/*
2287 	 * Now enable LPS, which we need in order to start accessing
2288 	 * most of the registers.  In fact, on some cards (ALI M5251),
2289 	 * accessing registers in the SClk domain without LPS enabled
2290 	 * will lock up the machine.  Wait 50msec to make sure we have
2291 	 * full link enabled.  However, with some cards (well, at least
2292 	 * a JMicron PCIe card), we have to try again sometimes.
2293 	 *
2294 	 * TI TSB82AA2 + TSB81BA3(A) cards signal LPS enabled early but
2295 	 * cannot actually use the phy at that time.  These need tens of
2296 	 * millisecods pause between LPS write and first phy access too.
2297 	 */
2298 
2299 	reg_write(ohci, OHCI1394_HCControlSet,
2300 		  OHCI1394_HCControl_LPS |
2301 		  OHCI1394_HCControl_postedWriteEnable);
2302 	flush_writes(ohci);
2303 
2304 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2305 		msleep(50);
2306 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2307 		      OHCI1394_HCControl_LPS;
2308 	}
2309 
2310 	if (!lps) {
2311 		ohci_err(ohci, "failed to set Link Power Status\n");
2312 		return -EIO;
2313 	}
2314 
2315 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2316 		ret = probe_tsb41ba3d(ohci);
2317 		if (ret < 0)
2318 			return ret;
2319 		if (ret)
2320 			ohci_notice(ohci, "local TSB41BA3D phy\n");
2321 		else
2322 			ohci->quirks &= ~QUIRK_TI_SLLZ059;
2323 	}
2324 
2325 	reg_write(ohci, OHCI1394_HCControlClear,
2326 		  OHCI1394_HCControl_noByteSwapData);
2327 
2328 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2329 	reg_write(ohci, OHCI1394_LinkControlSet,
2330 		  OHCI1394_LinkControl_cycleTimerEnable |
2331 		  OHCI1394_LinkControl_cycleMaster);
2332 
2333 	reg_write(ohci, OHCI1394_ATRetries,
2334 		  OHCI1394_MAX_AT_REQ_RETRIES |
2335 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2336 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2337 		  (200 << 16));
2338 
2339 	ohci->bus_time_running = false;
2340 
2341 	for (i = 0; i < 32; i++)
2342 		if (ohci->ir_context_support & (1 << i))
2343 			reg_write(ohci, OHCI1394_IsoRcvContextControlClear(i),
2344 				  IR_CONTEXT_MULTI_CHANNEL_MODE);
2345 
2346 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2347 	if (version >= OHCI_VERSION_1_1) {
2348 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2349 			  0xfffffffe);
2350 		card->broadcast_channel_auto_allocated = true;
2351 	}
2352 
2353 	/* Get implemented bits of the priority arbitration request counter. */
2354 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2355 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2356 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2357 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2358 
2359 	reg_write(ohci, OHCI1394_PhyUpperBound, FW_MAX_PHYSICAL_RANGE >> 16);
2360 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2361 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2362 
2363 	ret = configure_1394a_enhancements(ohci);
2364 	if (ret < 0)
2365 		return ret;
2366 
2367 	/* Activate link_on bit and contender bit in our self ID packets.*/
2368 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2369 	if (ret < 0)
2370 		return ret;
2371 
2372 	/*
2373 	 * When the link is not yet enabled, the atomic config rom
2374 	 * update mechanism described below in ohci_set_config_rom()
2375 	 * is not active.  We have to update ConfigRomHeader and
2376 	 * BusOptions manually, and the write to ConfigROMmap takes
2377 	 * effect immediately.  We tie this to the enabling of the
2378 	 * link, so we have a valid config rom before enabling - the
2379 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2380 	 * values before enabling.
2381 	 *
2382 	 * However, when the ConfigROMmap is written, some controllers
2383 	 * always read back quadlets 0 and 2 from the config rom to
2384 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2385 	 * They shouldn't do that in this initial case where the link
2386 	 * isn't enabled.  This means we have to use the same
2387 	 * workaround here, setting the bus header to 0 and then write
2388 	 * the right values in the bus reset tasklet.
2389 	 */
2390 
2391 	if (config_rom) {
2392 		ohci->next_config_rom =
2393 			dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2394 					   &ohci->next_config_rom_bus,
2395 					   GFP_KERNEL);
2396 		if (ohci->next_config_rom == NULL)
2397 			return -ENOMEM;
2398 
2399 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2400 	} else {
2401 		/*
2402 		 * In the suspend case, config_rom is NULL, which
2403 		 * means that we just reuse the old config rom.
2404 		 */
2405 		ohci->next_config_rom = ohci->config_rom;
2406 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2407 	}
2408 
2409 	ohci->next_header = ohci->next_config_rom[0];
2410 	ohci->next_config_rom[0] = 0;
2411 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2412 	reg_write(ohci, OHCI1394_BusOptions,
2413 		  be32_to_cpu(ohci->next_config_rom[2]));
2414 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2415 
2416 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2417 
2418 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2419 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2420 		OHCI1394_isochTx | OHCI1394_isochRx |
2421 		OHCI1394_postedWriteErr |
2422 		OHCI1394_selfIDComplete |
2423 		OHCI1394_regAccessFail |
2424 		OHCI1394_cycleInconsistent |
2425 		OHCI1394_unrecoverableError |
2426 		OHCI1394_cycleTooLong |
2427 		OHCI1394_masterIntEnable;
2428 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2429 		irqs |= OHCI1394_busReset;
2430 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2431 
2432 	reg_write(ohci, OHCI1394_HCControlSet,
2433 		  OHCI1394_HCControl_linkEnable |
2434 		  OHCI1394_HCControl_BIBimageValid);
2435 
2436 	reg_write(ohci, OHCI1394_LinkControlSet,
2437 		  OHCI1394_LinkControl_rcvSelfID |
2438 		  OHCI1394_LinkControl_rcvPhyPkt);
2439 
2440 	ar_context_run(&ohci->ar_request_ctx);
2441 	ar_context_run(&ohci->ar_response_ctx);
2442 
2443 	flush_writes(ohci);
2444 
2445 	/* We are ready to go, reset bus to finish initialization. */
2446 	fw_schedule_bus_reset(&ohci->card, false, true);
2447 
2448 	return 0;
2449 }
2450 
2451 static int ohci_set_config_rom(struct fw_card *card,
2452 			       const __be32 *config_rom, size_t length)
2453 {
2454 	struct fw_ohci *ohci;
2455 	__be32 *next_config_rom;
2456 	dma_addr_t uninitialized_var(next_config_rom_bus);
2457 
2458 	ohci = fw_ohci(card);
2459 
2460 	/*
2461 	 * When the OHCI controller is enabled, the config rom update
2462 	 * mechanism is a bit tricky, but easy enough to use.  See
2463 	 * section 5.5.6 in the OHCI specification.
2464 	 *
2465 	 * The OHCI controller caches the new config rom address in a
2466 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2467 	 * for the changes to take place.  When the bus reset is
2468 	 * detected, the controller loads the new values for the
2469 	 * ConfigRomHeader and BusOptions registers from the specified
2470 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2471 	 * shadow register. All automatically and atomically.
2472 	 *
2473 	 * Now, there's a twist to this story.  The automatic load of
2474 	 * ConfigRomHeader and BusOptions doesn't honor the
2475 	 * noByteSwapData bit, so with a be32 config rom, the
2476 	 * controller will load be32 values in to these registers
2477 	 * during the atomic update, even on litte endian
2478 	 * architectures.  The workaround we use is to put a 0 in the
2479 	 * header quadlet; 0 is endian agnostic and means that the
2480 	 * config rom isn't ready yet.  In the bus reset tasklet we
2481 	 * then set up the real values for the two registers.
2482 	 *
2483 	 * We use ohci->lock to avoid racing with the code that sets
2484 	 * ohci->next_config_rom to NULL (see bus_reset_work).
2485 	 */
2486 
2487 	next_config_rom =
2488 		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2489 				   &next_config_rom_bus, GFP_KERNEL);
2490 	if (next_config_rom == NULL)
2491 		return -ENOMEM;
2492 
2493 	spin_lock_irq(&ohci->lock);
2494 
2495 	/*
2496 	 * If there is not an already pending config_rom update,
2497 	 * push our new allocation into the ohci->next_config_rom
2498 	 * and then mark the local variable as null so that we
2499 	 * won't deallocate the new buffer.
2500 	 *
2501 	 * OTOH, if there is a pending config_rom update, just
2502 	 * use that buffer with the new config_rom data, and
2503 	 * let this routine free the unused DMA allocation.
2504 	 */
2505 
2506 	if (ohci->next_config_rom == NULL) {
2507 		ohci->next_config_rom = next_config_rom;
2508 		ohci->next_config_rom_bus = next_config_rom_bus;
2509 		next_config_rom = NULL;
2510 	}
2511 
2512 	copy_config_rom(ohci->next_config_rom, config_rom, length);
2513 
2514 	ohci->next_header = config_rom[0];
2515 	ohci->next_config_rom[0] = 0;
2516 
2517 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2518 
2519 	spin_unlock_irq(&ohci->lock);
2520 
2521 	/* If we didn't use the DMA allocation, delete it. */
2522 	if (next_config_rom != NULL)
2523 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2524 				  next_config_rom, next_config_rom_bus);
2525 
2526 	/*
2527 	 * Now initiate a bus reset to have the changes take
2528 	 * effect. We clean up the old config rom memory and DMA
2529 	 * mappings in the bus reset tasklet, since the OHCI
2530 	 * controller could need to access it before the bus reset
2531 	 * takes effect.
2532 	 */
2533 
2534 	fw_schedule_bus_reset(&ohci->card, true, true);
2535 
2536 	return 0;
2537 }
2538 
2539 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2540 {
2541 	struct fw_ohci *ohci = fw_ohci(card);
2542 
2543 	at_context_transmit(&ohci->at_request_ctx, packet);
2544 }
2545 
2546 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2547 {
2548 	struct fw_ohci *ohci = fw_ohci(card);
2549 
2550 	at_context_transmit(&ohci->at_response_ctx, packet);
2551 }
2552 
2553 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2554 {
2555 	struct fw_ohci *ohci = fw_ohci(card);
2556 	struct context *ctx = &ohci->at_request_ctx;
2557 	struct driver_data *driver_data = packet->driver_data;
2558 	int ret = -ENOENT;
2559 
2560 	tasklet_disable(&ctx->tasklet);
2561 
2562 	if (packet->ack != 0)
2563 		goto out;
2564 
2565 	if (packet->payload_mapped)
2566 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2567 				 packet->payload_length, DMA_TO_DEVICE);
2568 
2569 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, 0x20);
2570 	driver_data->packet = NULL;
2571 	packet->ack = RCODE_CANCELLED;
2572 	packet->callback(packet, &ohci->card, packet->ack);
2573 	ret = 0;
2574  out:
2575 	tasklet_enable(&ctx->tasklet);
2576 
2577 	return ret;
2578 }
2579 
2580 static int ohci_enable_phys_dma(struct fw_card *card,
2581 				int node_id, int generation)
2582 {
2583 	struct fw_ohci *ohci = fw_ohci(card);
2584 	unsigned long flags;
2585 	int n, ret = 0;
2586 
2587 	if (param_remote_dma)
2588 		return 0;
2589 
2590 	/*
2591 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2592 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2593 	 */
2594 
2595 	spin_lock_irqsave(&ohci->lock, flags);
2596 
2597 	if (ohci->generation != generation) {
2598 		ret = -ESTALE;
2599 		goto out;
2600 	}
2601 
2602 	/*
2603 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2604 	 * enabled for _all_ nodes on remote buses.
2605 	 */
2606 
2607 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2608 	if (n < 32)
2609 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2610 	else
2611 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2612 
2613 	flush_writes(ohci);
2614  out:
2615 	spin_unlock_irqrestore(&ohci->lock, flags);
2616 
2617 	return ret;
2618 }
2619 
2620 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2621 {
2622 	struct fw_ohci *ohci = fw_ohci(card);
2623 	unsigned long flags;
2624 	u32 value;
2625 
2626 	switch (csr_offset) {
2627 	case CSR_STATE_CLEAR:
2628 	case CSR_STATE_SET:
2629 		if (ohci->is_root &&
2630 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2631 		     OHCI1394_LinkControl_cycleMaster))
2632 			value = CSR_STATE_BIT_CMSTR;
2633 		else
2634 			value = 0;
2635 		if (ohci->csr_state_setclear_abdicate)
2636 			value |= CSR_STATE_BIT_ABDICATE;
2637 
2638 		return value;
2639 
2640 	case CSR_NODE_IDS:
2641 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2642 
2643 	case CSR_CYCLE_TIME:
2644 		return get_cycle_time(ohci);
2645 
2646 	case CSR_BUS_TIME:
2647 		/*
2648 		 * We might be called just after the cycle timer has wrapped
2649 		 * around but just before the cycle64Seconds handler, so we
2650 		 * better check here, too, if the bus time needs to be updated.
2651 		 */
2652 		spin_lock_irqsave(&ohci->lock, flags);
2653 		value = update_bus_time(ohci);
2654 		spin_unlock_irqrestore(&ohci->lock, flags);
2655 		return value;
2656 
2657 	case CSR_BUSY_TIMEOUT:
2658 		value = reg_read(ohci, OHCI1394_ATRetries);
2659 		return (value >> 4) & 0x0ffff00f;
2660 
2661 	case CSR_PRIORITY_BUDGET:
2662 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2663 			(ohci->pri_req_max << 8);
2664 
2665 	default:
2666 		WARN_ON(1);
2667 		return 0;
2668 	}
2669 }
2670 
2671 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2672 {
2673 	struct fw_ohci *ohci = fw_ohci(card);
2674 	unsigned long flags;
2675 
2676 	switch (csr_offset) {
2677 	case CSR_STATE_CLEAR:
2678 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2679 			reg_write(ohci, OHCI1394_LinkControlClear,
2680 				  OHCI1394_LinkControl_cycleMaster);
2681 			flush_writes(ohci);
2682 		}
2683 		if (value & CSR_STATE_BIT_ABDICATE)
2684 			ohci->csr_state_setclear_abdicate = false;
2685 		break;
2686 
2687 	case CSR_STATE_SET:
2688 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2689 			reg_write(ohci, OHCI1394_LinkControlSet,
2690 				  OHCI1394_LinkControl_cycleMaster);
2691 			flush_writes(ohci);
2692 		}
2693 		if (value & CSR_STATE_BIT_ABDICATE)
2694 			ohci->csr_state_setclear_abdicate = true;
2695 		break;
2696 
2697 	case CSR_NODE_IDS:
2698 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2699 		flush_writes(ohci);
2700 		break;
2701 
2702 	case CSR_CYCLE_TIME:
2703 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2704 		reg_write(ohci, OHCI1394_IntEventSet,
2705 			  OHCI1394_cycleInconsistent);
2706 		flush_writes(ohci);
2707 		break;
2708 
2709 	case CSR_BUS_TIME:
2710 		spin_lock_irqsave(&ohci->lock, flags);
2711 		ohci->bus_time = (update_bus_time(ohci) & 0x40) |
2712 		                 (value & ~0x7f);
2713 		spin_unlock_irqrestore(&ohci->lock, flags);
2714 		break;
2715 
2716 	case CSR_BUSY_TIMEOUT:
2717 		value = (value & 0xf) | ((value & 0xf) << 4) |
2718 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2719 		reg_write(ohci, OHCI1394_ATRetries, value);
2720 		flush_writes(ohci);
2721 		break;
2722 
2723 	case CSR_PRIORITY_BUDGET:
2724 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2725 		flush_writes(ohci);
2726 		break;
2727 
2728 	default:
2729 		WARN_ON(1);
2730 		break;
2731 	}
2732 }
2733 
2734 static void flush_iso_completions(struct iso_context *ctx)
2735 {
2736 	ctx->base.callback.sc(&ctx->base, ctx->last_timestamp,
2737 			      ctx->header_length, ctx->header,
2738 			      ctx->base.callback_data);
2739 	ctx->header_length = 0;
2740 }
2741 
2742 static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
2743 {
2744 	u32 *ctx_hdr;
2745 
2746 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
2747 		if (ctx->base.drop_overflow_headers)
2748 			return;
2749 		flush_iso_completions(ctx);
2750 	}
2751 
2752 	ctx_hdr = ctx->header + ctx->header_length;
2753 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
2754 
2755 	/*
2756 	 * The two iso header quadlets are byteswapped to little
2757 	 * endian by the controller, but we want to present them
2758 	 * as big endian for consistency with the bus endianness.
2759 	 */
2760 	if (ctx->base.header_size > 0)
2761 		ctx_hdr[0] = swab32(dma_hdr[1]); /* iso packet header */
2762 	if (ctx->base.header_size > 4)
2763 		ctx_hdr[1] = swab32(dma_hdr[0]); /* timestamp */
2764 	if (ctx->base.header_size > 8)
2765 		memcpy(&ctx_hdr[2], &dma_hdr[2], ctx->base.header_size - 8);
2766 	ctx->header_length += ctx->base.header_size;
2767 }
2768 
2769 static int handle_ir_packet_per_buffer(struct context *context,
2770 				       struct descriptor *d,
2771 				       struct descriptor *last)
2772 {
2773 	struct iso_context *ctx =
2774 		container_of(context, struct iso_context, context);
2775 	struct descriptor *pd;
2776 	u32 buffer_dma;
2777 
2778 	for (pd = d; pd <= last; pd++)
2779 		if (pd->transfer_status)
2780 			break;
2781 	if (pd > last)
2782 		/* Descriptor(s) not done yet, stop iteration */
2783 		return 0;
2784 
2785 	while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
2786 		d++;
2787 		buffer_dma = le32_to_cpu(d->data_address);
2788 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2789 					      buffer_dma & PAGE_MASK,
2790 					      buffer_dma & ~PAGE_MASK,
2791 					      le16_to_cpu(d->req_count),
2792 					      DMA_FROM_DEVICE);
2793 	}
2794 
2795 	copy_iso_headers(ctx, (u32 *) (last + 1));
2796 
2797 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2798 		flush_iso_completions(ctx);
2799 
2800 	return 1;
2801 }
2802 
2803 /* d == last because each descriptor block is only a single descriptor. */
2804 static int handle_ir_buffer_fill(struct context *context,
2805 				 struct descriptor *d,
2806 				 struct descriptor *last)
2807 {
2808 	struct iso_context *ctx =
2809 		container_of(context, struct iso_context, context);
2810 	unsigned int req_count, res_count, completed;
2811 	u32 buffer_dma;
2812 
2813 	req_count = le16_to_cpu(last->req_count);
2814 	res_count = le16_to_cpu(ACCESS_ONCE(last->res_count));
2815 	completed = req_count - res_count;
2816 	buffer_dma = le32_to_cpu(last->data_address);
2817 
2818 	if (completed > 0) {
2819 		ctx->mc_buffer_bus = buffer_dma;
2820 		ctx->mc_completed = completed;
2821 	}
2822 
2823 	if (res_count != 0)
2824 		/* Descriptor(s) not done yet, stop iteration */
2825 		return 0;
2826 
2827 	dma_sync_single_range_for_cpu(context->ohci->card.device,
2828 				      buffer_dma & PAGE_MASK,
2829 				      buffer_dma & ~PAGE_MASK,
2830 				      completed, DMA_FROM_DEVICE);
2831 
2832 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) {
2833 		ctx->base.callback.mc(&ctx->base,
2834 				      buffer_dma + completed,
2835 				      ctx->base.callback_data);
2836 		ctx->mc_completed = 0;
2837 	}
2838 
2839 	return 1;
2840 }
2841 
2842 static void flush_ir_buffer_fill(struct iso_context *ctx)
2843 {
2844 	dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
2845 				      ctx->mc_buffer_bus & PAGE_MASK,
2846 				      ctx->mc_buffer_bus & ~PAGE_MASK,
2847 				      ctx->mc_completed, DMA_FROM_DEVICE);
2848 
2849 	ctx->base.callback.mc(&ctx->base,
2850 			      ctx->mc_buffer_bus + ctx->mc_completed,
2851 			      ctx->base.callback_data);
2852 	ctx->mc_completed = 0;
2853 }
2854 
2855 static inline void sync_it_packet_for_cpu(struct context *context,
2856 					  struct descriptor *pd)
2857 {
2858 	__le16 control;
2859 	u32 buffer_dma;
2860 
2861 	/* only packets beginning with OUTPUT_MORE* have data buffers */
2862 	if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2863 		return;
2864 
2865 	/* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
2866 	pd += 2;
2867 
2868 	/*
2869 	 * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
2870 	 * data buffer is in the context program's coherent page and must not
2871 	 * be synced.
2872 	 */
2873 	if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
2874 	    (context->current_bus          & PAGE_MASK)) {
2875 		if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2876 			return;
2877 		pd++;
2878 	}
2879 
2880 	do {
2881 		buffer_dma = le32_to_cpu(pd->data_address);
2882 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2883 					      buffer_dma & PAGE_MASK,
2884 					      buffer_dma & ~PAGE_MASK,
2885 					      le16_to_cpu(pd->req_count),
2886 					      DMA_TO_DEVICE);
2887 		control = pd->control;
2888 		pd++;
2889 	} while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
2890 }
2891 
2892 static int handle_it_packet(struct context *context,
2893 			    struct descriptor *d,
2894 			    struct descriptor *last)
2895 {
2896 	struct iso_context *ctx =
2897 		container_of(context, struct iso_context, context);
2898 	struct descriptor *pd;
2899 	__be32 *ctx_hdr;
2900 
2901 	for (pd = d; pd <= last; pd++)
2902 		if (pd->transfer_status)
2903 			break;
2904 	if (pd > last)
2905 		/* Descriptor(s) not done yet, stop iteration */
2906 		return 0;
2907 
2908 	sync_it_packet_for_cpu(context, d);
2909 
2910 	if (ctx->header_length + 4 > PAGE_SIZE) {
2911 		if (ctx->base.drop_overflow_headers)
2912 			return 1;
2913 		flush_iso_completions(ctx);
2914 	}
2915 
2916 	ctx_hdr = ctx->header + ctx->header_length;
2917 	ctx->last_timestamp = le16_to_cpu(last->res_count);
2918 	/* Present this value as big-endian to match the receive code */
2919 	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
2920 			       le16_to_cpu(pd->res_count));
2921 	ctx->header_length += 4;
2922 
2923 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2924 		flush_iso_completions(ctx);
2925 
2926 	return 1;
2927 }
2928 
2929 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2930 {
2931 	u32 hi = channels >> 32, lo = channels;
2932 
2933 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2934 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2935 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2936 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2937 	mmiowb();
2938 	ohci->mc_channels = channels;
2939 }
2940 
2941 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2942 				int type, int channel, size_t header_size)
2943 {
2944 	struct fw_ohci *ohci = fw_ohci(card);
2945 	struct iso_context *uninitialized_var(ctx);
2946 	descriptor_callback_t uninitialized_var(callback);
2947 	u64 *uninitialized_var(channels);
2948 	u32 *uninitialized_var(mask), uninitialized_var(regs);
2949 	int index, ret = -EBUSY;
2950 
2951 	spin_lock_irq(&ohci->lock);
2952 
2953 	switch (type) {
2954 	case FW_ISO_CONTEXT_TRANSMIT:
2955 		mask     = &ohci->it_context_mask;
2956 		callback = handle_it_packet;
2957 		index    = ffs(*mask) - 1;
2958 		if (index >= 0) {
2959 			*mask &= ~(1 << index);
2960 			regs = OHCI1394_IsoXmitContextBase(index);
2961 			ctx  = &ohci->it_context_list[index];
2962 		}
2963 		break;
2964 
2965 	case FW_ISO_CONTEXT_RECEIVE:
2966 		channels = &ohci->ir_context_channels;
2967 		mask     = &ohci->ir_context_mask;
2968 		callback = handle_ir_packet_per_buffer;
2969 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2970 		if (index >= 0) {
2971 			*channels &= ~(1ULL << channel);
2972 			*mask     &= ~(1 << index);
2973 			regs = OHCI1394_IsoRcvContextBase(index);
2974 			ctx  = &ohci->ir_context_list[index];
2975 		}
2976 		break;
2977 
2978 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2979 		mask     = &ohci->ir_context_mask;
2980 		callback = handle_ir_buffer_fill;
2981 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2982 		if (index >= 0) {
2983 			ohci->mc_allocated = true;
2984 			*mask &= ~(1 << index);
2985 			regs = OHCI1394_IsoRcvContextBase(index);
2986 			ctx  = &ohci->ir_context_list[index];
2987 		}
2988 		break;
2989 
2990 	default:
2991 		index = -1;
2992 		ret = -ENOSYS;
2993 	}
2994 
2995 	spin_unlock_irq(&ohci->lock);
2996 
2997 	if (index < 0)
2998 		return ERR_PTR(ret);
2999 
3000 	memset(ctx, 0, sizeof(*ctx));
3001 	ctx->header_length = 0;
3002 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
3003 	if (ctx->header == NULL) {
3004 		ret = -ENOMEM;
3005 		goto out;
3006 	}
3007 	ret = context_init(&ctx->context, ohci, regs, callback);
3008 	if (ret < 0)
3009 		goto out_with_header;
3010 
3011 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
3012 		set_multichannel_mask(ohci, 0);
3013 		ctx->mc_completed = 0;
3014 	}
3015 
3016 	return &ctx->base;
3017 
3018  out_with_header:
3019 	free_page((unsigned long)ctx->header);
3020  out:
3021 	spin_lock_irq(&ohci->lock);
3022 
3023 	switch (type) {
3024 	case FW_ISO_CONTEXT_RECEIVE:
3025 		*channels |= 1ULL << channel;
3026 		break;
3027 
3028 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3029 		ohci->mc_allocated = false;
3030 		break;
3031 	}
3032 	*mask |= 1 << index;
3033 
3034 	spin_unlock_irq(&ohci->lock);
3035 
3036 	return ERR_PTR(ret);
3037 }
3038 
3039 static int ohci_start_iso(struct fw_iso_context *base,
3040 			  s32 cycle, u32 sync, u32 tags)
3041 {
3042 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3043 	struct fw_ohci *ohci = ctx->context.ohci;
3044 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
3045 	int index;
3046 
3047 	/* the controller cannot start without any queued packets */
3048 	if (ctx->context.last->branch_address == 0)
3049 		return -ENODATA;
3050 
3051 	switch (ctx->base.type) {
3052 	case FW_ISO_CONTEXT_TRANSMIT:
3053 		index = ctx - ohci->it_context_list;
3054 		match = 0;
3055 		if (cycle >= 0)
3056 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
3057 				(cycle & 0x7fff) << 16;
3058 
3059 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
3060 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
3061 		context_run(&ctx->context, match);
3062 		break;
3063 
3064 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3065 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
3066 		/* fall through */
3067 	case FW_ISO_CONTEXT_RECEIVE:
3068 		index = ctx - ohci->ir_context_list;
3069 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
3070 		if (cycle >= 0) {
3071 			match |= (cycle & 0x07fff) << 12;
3072 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
3073 		}
3074 
3075 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
3076 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
3077 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
3078 		context_run(&ctx->context, control);
3079 
3080 		ctx->sync = sync;
3081 		ctx->tags = tags;
3082 
3083 		break;
3084 	}
3085 
3086 	return 0;
3087 }
3088 
3089 static int ohci_stop_iso(struct fw_iso_context *base)
3090 {
3091 	struct fw_ohci *ohci = fw_ohci(base->card);
3092 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3093 	int index;
3094 
3095 	switch (ctx->base.type) {
3096 	case FW_ISO_CONTEXT_TRANSMIT:
3097 		index = ctx - ohci->it_context_list;
3098 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
3099 		break;
3100 
3101 	case FW_ISO_CONTEXT_RECEIVE:
3102 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3103 		index = ctx - ohci->ir_context_list;
3104 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
3105 		break;
3106 	}
3107 	flush_writes(ohci);
3108 	context_stop(&ctx->context);
3109 	tasklet_kill(&ctx->context.tasklet);
3110 
3111 	return 0;
3112 }
3113 
3114 static void ohci_free_iso_context(struct fw_iso_context *base)
3115 {
3116 	struct fw_ohci *ohci = fw_ohci(base->card);
3117 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3118 	unsigned long flags;
3119 	int index;
3120 
3121 	ohci_stop_iso(base);
3122 	context_release(&ctx->context);
3123 	free_page((unsigned long)ctx->header);
3124 
3125 	spin_lock_irqsave(&ohci->lock, flags);
3126 
3127 	switch (base->type) {
3128 	case FW_ISO_CONTEXT_TRANSMIT:
3129 		index = ctx - ohci->it_context_list;
3130 		ohci->it_context_mask |= 1 << index;
3131 		break;
3132 
3133 	case FW_ISO_CONTEXT_RECEIVE:
3134 		index = ctx - ohci->ir_context_list;
3135 		ohci->ir_context_mask |= 1 << index;
3136 		ohci->ir_context_channels |= 1ULL << base->channel;
3137 		break;
3138 
3139 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3140 		index = ctx - ohci->ir_context_list;
3141 		ohci->ir_context_mask |= 1 << index;
3142 		ohci->ir_context_channels |= ohci->mc_channels;
3143 		ohci->mc_channels = 0;
3144 		ohci->mc_allocated = false;
3145 		break;
3146 	}
3147 
3148 	spin_unlock_irqrestore(&ohci->lock, flags);
3149 }
3150 
3151 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
3152 {
3153 	struct fw_ohci *ohci = fw_ohci(base->card);
3154 	unsigned long flags;
3155 	int ret;
3156 
3157 	switch (base->type) {
3158 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3159 
3160 		spin_lock_irqsave(&ohci->lock, flags);
3161 
3162 		/* Don't allow multichannel to grab other contexts' channels. */
3163 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
3164 			*channels = ohci->ir_context_channels;
3165 			ret = -EBUSY;
3166 		} else {
3167 			set_multichannel_mask(ohci, *channels);
3168 			ret = 0;
3169 		}
3170 
3171 		spin_unlock_irqrestore(&ohci->lock, flags);
3172 
3173 		break;
3174 	default:
3175 		ret = -EINVAL;
3176 	}
3177 
3178 	return ret;
3179 }
3180 
3181 #ifdef CONFIG_PM
3182 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
3183 {
3184 	int i;
3185 	struct iso_context *ctx;
3186 
3187 	for (i = 0 ; i < ohci->n_ir ; i++) {
3188 		ctx = &ohci->ir_context_list[i];
3189 		if (ctx->context.running)
3190 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3191 	}
3192 
3193 	for (i = 0 ; i < ohci->n_it ; i++) {
3194 		ctx = &ohci->it_context_list[i];
3195 		if (ctx->context.running)
3196 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3197 	}
3198 }
3199 #endif
3200 
3201 static int queue_iso_transmit(struct iso_context *ctx,
3202 			      struct fw_iso_packet *packet,
3203 			      struct fw_iso_buffer *buffer,
3204 			      unsigned long payload)
3205 {
3206 	struct descriptor *d, *last, *pd;
3207 	struct fw_iso_packet *p;
3208 	__le32 *header;
3209 	dma_addr_t d_bus, page_bus;
3210 	u32 z, header_z, payload_z, irq;
3211 	u32 payload_index, payload_end_index, next_page_index;
3212 	int page, end_page, i, length, offset;
3213 
3214 	p = packet;
3215 	payload_index = payload;
3216 
3217 	if (p->skip)
3218 		z = 1;
3219 	else
3220 		z = 2;
3221 	if (p->header_length > 0)
3222 		z++;
3223 
3224 	/* Determine the first page the payload isn't contained in. */
3225 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
3226 	if (p->payload_length > 0)
3227 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
3228 	else
3229 		payload_z = 0;
3230 
3231 	z += payload_z;
3232 
3233 	/* Get header size in number of descriptors. */
3234 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
3235 
3236 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
3237 	if (d == NULL)
3238 		return -ENOMEM;
3239 
3240 	if (!p->skip) {
3241 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
3242 		d[0].req_count = cpu_to_le16(8);
3243 		/*
3244 		 * Link the skip address to this descriptor itself.  This causes
3245 		 * a context to skip a cycle whenever lost cycles or FIFO
3246 		 * overruns occur, without dropping the data.  The application
3247 		 * should then decide whether this is an error condition or not.
3248 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
3249 		 */
3250 		d[0].branch_address = cpu_to_le32(d_bus | z);
3251 
3252 		header = (__le32 *) &d[1];
3253 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
3254 					IT_HEADER_TAG(p->tag) |
3255 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
3256 					IT_HEADER_CHANNEL(ctx->base.channel) |
3257 					IT_HEADER_SPEED(ctx->base.speed));
3258 		header[1] =
3259 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
3260 							  p->payload_length));
3261 	}
3262 
3263 	if (p->header_length > 0) {
3264 		d[2].req_count    = cpu_to_le16(p->header_length);
3265 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
3266 		memcpy(&d[z], p->header, p->header_length);
3267 	}
3268 
3269 	pd = d + z - payload_z;
3270 	payload_end_index = payload_index + p->payload_length;
3271 	for (i = 0; i < payload_z; i++) {
3272 		page               = payload_index >> PAGE_SHIFT;
3273 		offset             = payload_index & ~PAGE_MASK;
3274 		next_page_index    = (page + 1) << PAGE_SHIFT;
3275 		length             =
3276 			min(next_page_index, payload_end_index) - payload_index;
3277 		pd[i].req_count    = cpu_to_le16(length);
3278 
3279 		page_bus = page_private(buffer->pages[page]);
3280 		pd[i].data_address = cpu_to_le32(page_bus + offset);
3281 
3282 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3283 						 page_bus, offset, length,
3284 						 DMA_TO_DEVICE);
3285 
3286 		payload_index += length;
3287 	}
3288 
3289 	if (p->interrupt)
3290 		irq = DESCRIPTOR_IRQ_ALWAYS;
3291 	else
3292 		irq = DESCRIPTOR_NO_IRQ;
3293 
3294 	last = z == 2 ? d : d + z - 1;
3295 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
3296 				     DESCRIPTOR_STATUS |
3297 				     DESCRIPTOR_BRANCH_ALWAYS |
3298 				     irq);
3299 
3300 	context_append(&ctx->context, d, z, header_z);
3301 
3302 	return 0;
3303 }
3304 
3305 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
3306 				       struct fw_iso_packet *packet,
3307 				       struct fw_iso_buffer *buffer,
3308 				       unsigned long payload)
3309 {
3310 	struct device *device = ctx->context.ohci->card.device;
3311 	struct descriptor *d, *pd;
3312 	dma_addr_t d_bus, page_bus;
3313 	u32 z, header_z, rest;
3314 	int i, j, length;
3315 	int page, offset, packet_count, header_size, payload_per_buffer;
3316 
3317 	/*
3318 	 * The OHCI controller puts the isochronous header and trailer in the
3319 	 * buffer, so we need at least 8 bytes.
3320 	 */
3321 	packet_count = packet->header_length / ctx->base.header_size;
3322 	header_size  = max(ctx->base.header_size, (size_t)8);
3323 
3324 	/* Get header size in number of descriptors. */
3325 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
3326 	page     = payload >> PAGE_SHIFT;
3327 	offset   = payload & ~PAGE_MASK;
3328 	payload_per_buffer = packet->payload_length / packet_count;
3329 
3330 	for (i = 0; i < packet_count; i++) {
3331 		/* d points to the header descriptor */
3332 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
3333 		d = context_get_descriptors(&ctx->context,
3334 				z + header_z, &d_bus);
3335 		if (d == NULL)
3336 			return -ENOMEM;
3337 
3338 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3339 					      DESCRIPTOR_INPUT_MORE);
3340 		if (packet->skip && i == 0)
3341 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3342 		d->req_count    = cpu_to_le16(header_size);
3343 		d->res_count    = d->req_count;
3344 		d->transfer_status = 0;
3345 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3346 
3347 		rest = payload_per_buffer;
3348 		pd = d;
3349 		for (j = 1; j < z; j++) {
3350 			pd++;
3351 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3352 						  DESCRIPTOR_INPUT_MORE);
3353 
3354 			if (offset + rest < PAGE_SIZE)
3355 				length = rest;
3356 			else
3357 				length = PAGE_SIZE - offset;
3358 			pd->req_count = cpu_to_le16(length);
3359 			pd->res_count = pd->req_count;
3360 			pd->transfer_status = 0;
3361 
3362 			page_bus = page_private(buffer->pages[page]);
3363 			pd->data_address = cpu_to_le32(page_bus + offset);
3364 
3365 			dma_sync_single_range_for_device(device, page_bus,
3366 							 offset, length,
3367 							 DMA_FROM_DEVICE);
3368 
3369 			offset = (offset + length) & ~PAGE_MASK;
3370 			rest -= length;
3371 			if (offset == 0)
3372 				page++;
3373 		}
3374 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3375 					  DESCRIPTOR_INPUT_LAST |
3376 					  DESCRIPTOR_BRANCH_ALWAYS);
3377 		if (packet->interrupt && i == packet_count - 1)
3378 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3379 
3380 		context_append(&ctx->context, d, z, header_z);
3381 	}
3382 
3383 	return 0;
3384 }
3385 
3386 static int queue_iso_buffer_fill(struct iso_context *ctx,
3387 				 struct fw_iso_packet *packet,
3388 				 struct fw_iso_buffer *buffer,
3389 				 unsigned long payload)
3390 {
3391 	struct descriptor *d;
3392 	dma_addr_t d_bus, page_bus;
3393 	int page, offset, rest, z, i, length;
3394 
3395 	page   = payload >> PAGE_SHIFT;
3396 	offset = payload & ~PAGE_MASK;
3397 	rest   = packet->payload_length;
3398 
3399 	/* We need one descriptor for each page in the buffer. */
3400 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3401 
3402 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3403 		return -EFAULT;
3404 
3405 	for (i = 0; i < z; i++) {
3406 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3407 		if (d == NULL)
3408 			return -ENOMEM;
3409 
3410 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3411 					 DESCRIPTOR_BRANCH_ALWAYS);
3412 		if (packet->skip && i == 0)
3413 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3414 		if (packet->interrupt && i == z - 1)
3415 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3416 
3417 		if (offset + rest < PAGE_SIZE)
3418 			length = rest;
3419 		else
3420 			length = PAGE_SIZE - offset;
3421 		d->req_count = cpu_to_le16(length);
3422 		d->res_count = d->req_count;
3423 		d->transfer_status = 0;
3424 
3425 		page_bus = page_private(buffer->pages[page]);
3426 		d->data_address = cpu_to_le32(page_bus + offset);
3427 
3428 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3429 						 page_bus, offset, length,
3430 						 DMA_FROM_DEVICE);
3431 
3432 		rest -= length;
3433 		offset = 0;
3434 		page++;
3435 
3436 		context_append(&ctx->context, d, 1, 0);
3437 	}
3438 
3439 	return 0;
3440 }
3441 
3442 static int ohci_queue_iso(struct fw_iso_context *base,
3443 			  struct fw_iso_packet *packet,
3444 			  struct fw_iso_buffer *buffer,
3445 			  unsigned long payload)
3446 {
3447 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3448 	unsigned long flags;
3449 	int ret = -ENOSYS;
3450 
3451 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3452 	switch (base->type) {
3453 	case FW_ISO_CONTEXT_TRANSMIT:
3454 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3455 		break;
3456 	case FW_ISO_CONTEXT_RECEIVE:
3457 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3458 		break;
3459 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3460 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3461 		break;
3462 	}
3463 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3464 
3465 	return ret;
3466 }
3467 
3468 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3469 {
3470 	struct context *ctx =
3471 			&container_of(base, struct iso_context, base)->context;
3472 
3473 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3474 }
3475 
3476 static int ohci_flush_iso_completions(struct fw_iso_context *base)
3477 {
3478 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3479 	int ret = 0;
3480 
3481 	tasklet_disable(&ctx->context.tasklet);
3482 
3483 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
3484 		context_tasklet((unsigned long)&ctx->context);
3485 
3486 		switch (base->type) {
3487 		case FW_ISO_CONTEXT_TRANSMIT:
3488 		case FW_ISO_CONTEXT_RECEIVE:
3489 			if (ctx->header_length != 0)
3490 				flush_iso_completions(ctx);
3491 			break;
3492 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3493 			if (ctx->mc_completed != 0)
3494 				flush_ir_buffer_fill(ctx);
3495 			break;
3496 		default:
3497 			ret = -ENOSYS;
3498 		}
3499 
3500 		clear_bit_unlock(0, &ctx->flushing_completions);
3501 		smp_mb__after_atomic();
3502 	}
3503 
3504 	tasklet_enable(&ctx->context.tasklet);
3505 
3506 	return ret;
3507 }
3508 
3509 static const struct fw_card_driver ohci_driver = {
3510 	.enable			= ohci_enable,
3511 	.read_phy_reg		= ohci_read_phy_reg,
3512 	.update_phy_reg		= ohci_update_phy_reg,
3513 	.set_config_rom		= ohci_set_config_rom,
3514 	.send_request		= ohci_send_request,
3515 	.send_response		= ohci_send_response,
3516 	.cancel_packet		= ohci_cancel_packet,
3517 	.enable_phys_dma	= ohci_enable_phys_dma,
3518 	.read_csr		= ohci_read_csr,
3519 	.write_csr		= ohci_write_csr,
3520 
3521 	.allocate_iso_context	= ohci_allocate_iso_context,
3522 	.free_iso_context	= ohci_free_iso_context,
3523 	.set_iso_channels	= ohci_set_iso_channels,
3524 	.queue_iso		= ohci_queue_iso,
3525 	.flush_queue_iso	= ohci_flush_queue_iso,
3526 	.flush_iso_completions	= ohci_flush_iso_completions,
3527 	.start_iso		= ohci_start_iso,
3528 	.stop_iso		= ohci_stop_iso,
3529 };
3530 
3531 #ifdef CONFIG_PPC_PMAC
3532 static void pmac_ohci_on(struct pci_dev *dev)
3533 {
3534 	if (machine_is(powermac)) {
3535 		struct device_node *ofn = pci_device_to_OF_node(dev);
3536 
3537 		if (ofn) {
3538 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3539 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3540 		}
3541 	}
3542 }
3543 
3544 static void pmac_ohci_off(struct pci_dev *dev)
3545 {
3546 	if (machine_is(powermac)) {
3547 		struct device_node *ofn = pci_device_to_OF_node(dev);
3548 
3549 		if (ofn) {
3550 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3551 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3552 		}
3553 	}
3554 }
3555 #else
3556 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3557 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3558 #endif /* CONFIG_PPC_PMAC */
3559 
3560 static int pci_probe(struct pci_dev *dev,
3561 			       const struct pci_device_id *ent)
3562 {
3563 	struct fw_ohci *ohci;
3564 	u32 bus_options, max_receive, link_speed, version;
3565 	u64 guid;
3566 	int i, err;
3567 	size_t size;
3568 
3569 	if (dev->vendor == PCI_VENDOR_ID_PINNACLE_SYSTEMS) {
3570 		dev_err(&dev->dev, "Pinnacle MovieBoard is not yet supported\n");
3571 		return -ENOSYS;
3572 	}
3573 
3574 	ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3575 	if (ohci == NULL) {
3576 		err = -ENOMEM;
3577 		goto fail;
3578 	}
3579 
3580 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3581 
3582 	pmac_ohci_on(dev);
3583 
3584 	err = pci_enable_device(dev);
3585 	if (err) {
3586 		dev_err(&dev->dev, "failed to enable OHCI hardware\n");
3587 		goto fail_free;
3588 	}
3589 
3590 	pci_set_master(dev);
3591 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3592 	pci_set_drvdata(dev, ohci);
3593 
3594 	spin_lock_init(&ohci->lock);
3595 	mutex_init(&ohci->phy_reg_mutex);
3596 
3597 	INIT_WORK(&ohci->bus_reset_work, bus_reset_work);
3598 
3599 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM) ||
3600 	    pci_resource_len(dev, 0) < OHCI1394_REGISTER_SIZE) {
3601 		ohci_err(ohci, "invalid MMIO resource\n");
3602 		err = -ENXIO;
3603 		goto fail_disable;
3604 	}
3605 
3606 	err = pci_request_region(dev, 0, ohci_driver_name);
3607 	if (err) {
3608 		ohci_err(ohci, "MMIO resource unavailable\n");
3609 		goto fail_disable;
3610 	}
3611 
3612 	ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3613 	if (ohci->registers == NULL) {
3614 		ohci_err(ohci, "failed to remap registers\n");
3615 		err = -ENXIO;
3616 		goto fail_iomem;
3617 	}
3618 
3619 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3620 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3621 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3622 		     ohci_quirks[i].device == dev->device) &&
3623 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3624 		     ohci_quirks[i].revision >= dev->revision)) {
3625 			ohci->quirks = ohci_quirks[i].flags;
3626 			break;
3627 		}
3628 	if (param_quirks)
3629 		ohci->quirks = param_quirks;
3630 
3631 	/*
3632 	 * Because dma_alloc_coherent() allocates at least one page,
3633 	 * we save space by using a common buffer for the AR request/
3634 	 * response descriptors and the self IDs buffer.
3635 	 */
3636 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3637 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3638 	ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3639 					       PAGE_SIZE,
3640 					       &ohci->misc_buffer_bus,
3641 					       GFP_KERNEL);
3642 	if (!ohci->misc_buffer) {
3643 		err = -ENOMEM;
3644 		goto fail_iounmap;
3645 	}
3646 
3647 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3648 			      OHCI1394_AsReqRcvContextControlSet);
3649 	if (err < 0)
3650 		goto fail_misc_buf;
3651 
3652 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3653 			      OHCI1394_AsRspRcvContextControlSet);
3654 	if (err < 0)
3655 		goto fail_arreq_ctx;
3656 
3657 	err = context_init(&ohci->at_request_ctx, ohci,
3658 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3659 	if (err < 0)
3660 		goto fail_arrsp_ctx;
3661 
3662 	err = context_init(&ohci->at_response_ctx, ohci,
3663 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3664 	if (err < 0)
3665 		goto fail_atreq_ctx;
3666 
3667 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3668 	ohci->ir_context_channels = ~0ULL;
3669 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3670 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3671 	ohci->ir_context_mask = ohci->ir_context_support;
3672 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3673 	size = sizeof(struct iso_context) * ohci->n_ir;
3674 	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3675 
3676 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3677 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3678 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3679 	ohci->it_context_mask = ohci->it_context_support;
3680 	ohci->n_it = hweight32(ohci->it_context_mask);
3681 	size = sizeof(struct iso_context) * ohci->n_it;
3682 	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3683 
3684 	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3685 		err = -ENOMEM;
3686 		goto fail_contexts;
3687 	}
3688 
3689 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
3690 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3691 
3692 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3693 	max_receive = (bus_options >> 12) & 0xf;
3694 	link_speed = bus_options & 0x7;
3695 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3696 		reg_read(ohci, OHCI1394_GUIDLo);
3697 
3698 	if (!(ohci->quirks & QUIRK_NO_MSI))
3699 		pci_enable_msi(dev);
3700 	if (request_irq(dev->irq, irq_handler,
3701 			pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
3702 			ohci_driver_name, ohci)) {
3703 		ohci_err(ohci, "failed to allocate interrupt %d\n", dev->irq);
3704 		err = -EIO;
3705 		goto fail_msi;
3706 	}
3707 
3708 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3709 	if (err)
3710 		goto fail_irq;
3711 
3712 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3713 	ohci_notice(ohci,
3714 		    "added OHCI v%x.%x device as card %d, "
3715 		    "%d IR + %d IT contexts, quirks 0x%x%s\n",
3716 		    version >> 16, version & 0xff, ohci->card.index,
3717 		    ohci->n_ir, ohci->n_it, ohci->quirks,
3718 		    reg_read(ohci, OHCI1394_PhyUpperBound) ?
3719 			", physUB" : "");
3720 
3721 	return 0;
3722 
3723  fail_irq:
3724 	free_irq(dev->irq, ohci);
3725  fail_msi:
3726 	pci_disable_msi(dev);
3727  fail_contexts:
3728 	kfree(ohci->ir_context_list);
3729 	kfree(ohci->it_context_list);
3730 	context_release(&ohci->at_response_ctx);
3731  fail_atreq_ctx:
3732 	context_release(&ohci->at_request_ctx);
3733  fail_arrsp_ctx:
3734 	ar_context_release(&ohci->ar_response_ctx);
3735  fail_arreq_ctx:
3736 	ar_context_release(&ohci->ar_request_ctx);
3737  fail_misc_buf:
3738 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3739 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3740  fail_iounmap:
3741 	pci_iounmap(dev, ohci->registers);
3742  fail_iomem:
3743 	pci_release_region(dev, 0);
3744  fail_disable:
3745 	pci_disable_device(dev);
3746  fail_free:
3747 	kfree(ohci);
3748 	pmac_ohci_off(dev);
3749  fail:
3750 	return err;
3751 }
3752 
3753 static void pci_remove(struct pci_dev *dev)
3754 {
3755 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3756 
3757 	/*
3758 	 * If the removal is happening from the suspend state, LPS won't be
3759 	 * enabled and host registers (eg., IntMaskClear) won't be accessible.
3760 	 */
3761 	if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) {
3762 		reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3763 		flush_writes(ohci);
3764 	}
3765 	cancel_work_sync(&ohci->bus_reset_work);
3766 	fw_core_remove_card(&ohci->card);
3767 
3768 	/*
3769 	 * FIXME: Fail all pending packets here, now that the upper
3770 	 * layers can't queue any more.
3771 	 */
3772 
3773 	software_reset(ohci);
3774 	free_irq(dev->irq, ohci);
3775 
3776 	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3777 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3778 				  ohci->next_config_rom, ohci->next_config_rom_bus);
3779 	if (ohci->config_rom)
3780 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3781 				  ohci->config_rom, ohci->config_rom_bus);
3782 	ar_context_release(&ohci->ar_request_ctx);
3783 	ar_context_release(&ohci->ar_response_ctx);
3784 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3785 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3786 	context_release(&ohci->at_request_ctx);
3787 	context_release(&ohci->at_response_ctx);
3788 	kfree(ohci->it_context_list);
3789 	kfree(ohci->ir_context_list);
3790 	pci_disable_msi(dev);
3791 	pci_iounmap(dev, ohci->registers);
3792 	pci_release_region(dev, 0);
3793 	pci_disable_device(dev);
3794 	kfree(ohci);
3795 	pmac_ohci_off(dev);
3796 
3797 	dev_notice(&dev->dev, "removed fw-ohci device\n");
3798 }
3799 
3800 #ifdef CONFIG_PM
3801 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3802 {
3803 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3804 	int err;
3805 
3806 	software_reset(ohci);
3807 	err = pci_save_state(dev);
3808 	if (err) {
3809 		ohci_err(ohci, "pci_save_state failed\n");
3810 		return err;
3811 	}
3812 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3813 	if (err)
3814 		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
3815 	pmac_ohci_off(dev);
3816 
3817 	return 0;
3818 }
3819 
3820 static int pci_resume(struct pci_dev *dev)
3821 {
3822 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3823 	int err;
3824 
3825 	pmac_ohci_on(dev);
3826 	pci_set_power_state(dev, PCI_D0);
3827 	pci_restore_state(dev);
3828 	err = pci_enable_device(dev);
3829 	if (err) {
3830 		ohci_err(ohci, "pci_enable_device failed\n");
3831 		return err;
3832 	}
3833 
3834 	/* Some systems don't setup GUID register on resume from ram  */
3835 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3836 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3837 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3838 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3839 	}
3840 
3841 	err = ohci_enable(&ohci->card, NULL, 0);
3842 	if (err)
3843 		return err;
3844 
3845 	ohci_resume_iso_dma(ohci);
3846 
3847 	return 0;
3848 }
3849 #endif
3850 
3851 static const struct pci_device_id pci_table[] = {
3852 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3853 	{ }
3854 };
3855 
3856 MODULE_DEVICE_TABLE(pci, pci_table);
3857 
3858 static struct pci_driver fw_ohci_pci_driver = {
3859 	.name		= ohci_driver_name,
3860 	.id_table	= pci_table,
3861 	.probe		= pci_probe,
3862 	.remove		= pci_remove,
3863 #ifdef CONFIG_PM
3864 	.resume		= pci_resume,
3865 	.suspend	= pci_suspend,
3866 #endif
3867 };
3868 
3869 static int __init fw_ohci_init(void)
3870 {
3871 	selfid_workqueue = alloc_workqueue(KBUILD_MODNAME, WQ_MEM_RECLAIM, 0);
3872 	if (!selfid_workqueue)
3873 		return -ENOMEM;
3874 
3875 	return pci_register_driver(&fw_ohci_pci_driver);
3876 }
3877 
3878 static void __exit fw_ohci_cleanup(void)
3879 {
3880 	pci_unregister_driver(&fw_ohci_pci_driver);
3881 	destroy_workqueue(selfid_workqueue);
3882 }
3883 
3884 module_init(fw_ohci_init);
3885 module_exit(fw_ohci_cleanup);
3886 
3887 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3888 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3889 MODULE_LICENSE("GPL");
3890 
3891 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3892 MODULE_ALIAS("ohci1394");
3893