xref: /openbmc/linux/drivers/firewire/ohci.c (revision afc98d90)
1 /*
2  * Driver for OHCI 1394 controllers
3  *
4  * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 #include <linux/bitops.h>
22 #include <linux/bug.h>
23 #include <linux/compiler.h>
24 #include <linux/delay.h>
25 #include <linux/device.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/firewire.h>
28 #include <linux/firewire-constants.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/io.h>
32 #include <linux/kernel.h>
33 #include <linux/list.h>
34 #include <linux/mm.h>
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/mutex.h>
38 #include <linux/pci.h>
39 #include <linux/pci_ids.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/string.h>
43 #include <linux/time.h>
44 #include <linux/vmalloc.h>
45 #include <linux/workqueue.h>
46 
47 #include <asm/byteorder.h>
48 #include <asm/page.h>
49 
50 #ifdef CONFIG_PPC_PMAC
51 #include <asm/pmac_feature.h>
52 #endif
53 
54 #include "core.h"
55 #include "ohci.h"
56 
57 #define ohci_info(ohci, f, args...)	dev_info(ohci->card.device, f, ##args)
58 #define ohci_notice(ohci, f, args...)	dev_notice(ohci->card.device, f, ##args)
59 #define ohci_err(ohci, f, args...)	dev_err(ohci->card.device, f, ##args)
60 
61 #define DESCRIPTOR_OUTPUT_MORE		0
62 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
63 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
64 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
65 #define DESCRIPTOR_STATUS		(1 << 11)
66 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
67 #define DESCRIPTOR_PING			(1 << 7)
68 #define DESCRIPTOR_YY			(1 << 6)
69 #define DESCRIPTOR_NO_IRQ		(0 << 4)
70 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
71 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
72 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
73 #define DESCRIPTOR_WAIT			(3 << 0)
74 
75 #define DESCRIPTOR_CMD			(0xf << 12)
76 
77 struct descriptor {
78 	__le16 req_count;
79 	__le16 control;
80 	__le32 data_address;
81 	__le32 branch_address;
82 	__le16 res_count;
83 	__le16 transfer_status;
84 } __attribute__((aligned(16)));
85 
86 #define CONTROL_SET(regs)	(regs)
87 #define CONTROL_CLEAR(regs)	((regs) + 4)
88 #define COMMAND_PTR(regs)	((regs) + 12)
89 #define CONTEXT_MATCH(regs)	((regs) + 16)
90 
91 #define AR_BUFFER_SIZE	(32*1024)
92 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
93 /* we need at least two pages for proper list management */
94 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
95 
96 #define MAX_ASYNC_PAYLOAD	4096
97 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
98 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
99 
100 struct ar_context {
101 	struct fw_ohci *ohci;
102 	struct page *pages[AR_BUFFERS];
103 	void *buffer;
104 	struct descriptor *descriptors;
105 	dma_addr_t descriptors_bus;
106 	void *pointer;
107 	unsigned int last_buffer_index;
108 	u32 regs;
109 	struct tasklet_struct tasklet;
110 };
111 
112 struct context;
113 
114 typedef int (*descriptor_callback_t)(struct context *ctx,
115 				     struct descriptor *d,
116 				     struct descriptor *last);
117 
118 /*
119  * A buffer that contains a block of DMA-able coherent memory used for
120  * storing a portion of a DMA descriptor program.
121  */
122 struct descriptor_buffer {
123 	struct list_head list;
124 	dma_addr_t buffer_bus;
125 	size_t buffer_size;
126 	size_t used;
127 	struct descriptor buffer[0];
128 };
129 
130 struct context {
131 	struct fw_ohci *ohci;
132 	u32 regs;
133 	int total_allocation;
134 	u32 current_bus;
135 	bool running;
136 	bool flushing;
137 
138 	/*
139 	 * List of page-sized buffers for storing DMA descriptors.
140 	 * Head of list contains buffers in use and tail of list contains
141 	 * free buffers.
142 	 */
143 	struct list_head buffer_list;
144 
145 	/*
146 	 * Pointer to a buffer inside buffer_list that contains the tail
147 	 * end of the current DMA program.
148 	 */
149 	struct descriptor_buffer *buffer_tail;
150 
151 	/*
152 	 * The descriptor containing the branch address of the first
153 	 * descriptor that has not yet been filled by the device.
154 	 */
155 	struct descriptor *last;
156 
157 	/*
158 	 * The last descriptor block in the DMA program. It contains the branch
159 	 * address that must be updated upon appending a new descriptor.
160 	 */
161 	struct descriptor *prev;
162 	int prev_z;
163 
164 	descriptor_callback_t callback;
165 
166 	struct tasklet_struct tasklet;
167 };
168 
169 #define IT_HEADER_SY(v)          ((v) <<  0)
170 #define IT_HEADER_TCODE(v)       ((v) <<  4)
171 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
172 #define IT_HEADER_TAG(v)         ((v) << 14)
173 #define IT_HEADER_SPEED(v)       ((v) << 16)
174 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
175 
176 struct iso_context {
177 	struct fw_iso_context base;
178 	struct context context;
179 	void *header;
180 	size_t header_length;
181 	unsigned long flushing_completions;
182 	u32 mc_buffer_bus;
183 	u16 mc_completed;
184 	u16 last_timestamp;
185 	u8 sync;
186 	u8 tags;
187 };
188 
189 #define CONFIG_ROM_SIZE 1024
190 
191 struct fw_ohci {
192 	struct fw_card card;
193 
194 	__iomem char *registers;
195 	int node_id;
196 	int generation;
197 	int request_generation;	/* for timestamping incoming requests */
198 	unsigned quirks;
199 	unsigned int pri_req_max;
200 	u32 bus_time;
201 	bool bus_time_running;
202 	bool is_root;
203 	bool csr_state_setclear_abdicate;
204 	int n_ir;
205 	int n_it;
206 	/*
207 	 * Spinlock for accessing fw_ohci data.  Never call out of
208 	 * this driver with this lock held.
209 	 */
210 	spinlock_t lock;
211 
212 	struct mutex phy_reg_mutex;
213 
214 	void *misc_buffer;
215 	dma_addr_t misc_buffer_bus;
216 
217 	struct ar_context ar_request_ctx;
218 	struct ar_context ar_response_ctx;
219 	struct context at_request_ctx;
220 	struct context at_response_ctx;
221 
222 	u32 it_context_support;
223 	u32 it_context_mask;     /* unoccupied IT contexts */
224 	struct iso_context *it_context_list;
225 	u64 ir_context_channels; /* unoccupied channels */
226 	u32 ir_context_support;
227 	u32 ir_context_mask;     /* unoccupied IR contexts */
228 	struct iso_context *ir_context_list;
229 	u64 mc_channels; /* channels in use by the multichannel IR context */
230 	bool mc_allocated;
231 
232 	__be32    *config_rom;
233 	dma_addr_t config_rom_bus;
234 	__be32    *next_config_rom;
235 	dma_addr_t next_config_rom_bus;
236 	__be32     next_header;
237 
238 	__le32    *self_id;
239 	dma_addr_t self_id_bus;
240 	struct work_struct bus_reset_work;
241 
242 	u32 self_id_buffer[512];
243 };
244 
245 static struct workqueue_struct *selfid_workqueue;
246 
247 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
248 {
249 	return container_of(card, struct fw_ohci, card);
250 }
251 
252 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
253 #define IR_CONTEXT_BUFFER_FILL		0x80000000
254 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
255 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
256 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
257 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
258 
259 #define CONTEXT_RUN	0x8000
260 #define CONTEXT_WAKE	0x1000
261 #define CONTEXT_DEAD	0x0800
262 #define CONTEXT_ACTIVE	0x0400
263 
264 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
265 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
266 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
267 
268 #define OHCI1394_REGISTER_SIZE		0x800
269 #define OHCI1394_PCI_HCI_Control	0x40
270 #define SELF_ID_BUF_SIZE		0x800
271 #define OHCI_TCODE_PHY_PACKET		0x0e
272 #define OHCI_VERSION_1_1		0x010010
273 
274 static char ohci_driver_name[] = KBUILD_MODNAME;
275 
276 #define PCI_VENDOR_ID_PINNACLE_SYSTEMS	0x11bd
277 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
278 #define PCI_DEVICE_ID_CREATIVE_SB1394	0x4001
279 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
280 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
281 #define PCI_DEVICE_ID_TI_TSB12LV26	0x8020
282 #define PCI_DEVICE_ID_TI_TSB82AA2	0x8025
283 #define PCI_DEVICE_ID_VIA_VT630X	0x3044
284 #define PCI_REV_ID_VIA_VT6306		0x46
285 
286 #define QUIRK_CYCLE_TIMER		0x1
287 #define QUIRK_RESET_PACKET		0x2
288 #define QUIRK_BE_HEADERS		0x4
289 #define QUIRK_NO_1394A			0x8
290 #define QUIRK_NO_MSI			0x10
291 #define QUIRK_TI_SLLZ059		0x20
292 #define QUIRK_IR_WAKE			0x40
293 #define QUIRK_PHY_LCTRL_TIMEOUT		0x80
294 
295 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
296 static const struct {
297 	unsigned short vendor, device, revision, flags;
298 } ohci_quirks[] = {
299 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
300 		QUIRK_CYCLE_TIMER},
301 
302 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
303 		QUIRK_BE_HEADERS},
304 
305 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
306 		QUIRK_PHY_LCTRL_TIMEOUT | QUIRK_NO_MSI},
307 
308 	{PCI_VENDOR_ID_ATT, PCI_ANY_ID, PCI_ANY_ID,
309 		QUIRK_PHY_LCTRL_TIMEOUT},
310 
311 	{PCI_VENDOR_ID_CREATIVE, PCI_DEVICE_ID_CREATIVE_SB1394, PCI_ANY_ID,
312 		QUIRK_RESET_PACKET},
313 
314 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
315 		QUIRK_NO_MSI},
316 
317 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
318 		QUIRK_CYCLE_TIMER},
319 
320 	{PCI_VENDOR_ID_O2, PCI_ANY_ID, PCI_ANY_ID,
321 		QUIRK_NO_MSI},
322 
323 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
324 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
325 
326 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
327 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
328 
329 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV26, PCI_ANY_ID,
330 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
331 
332 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB82AA2, PCI_ANY_ID,
333 		QUIRK_RESET_PACKET | QUIRK_TI_SLLZ059},
334 
335 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
336 		QUIRK_RESET_PACKET},
337 
338 	{PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VT630X, PCI_REV_ID_VIA_VT6306,
339 		QUIRK_CYCLE_TIMER | QUIRK_IR_WAKE},
340 
341 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
342 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
343 };
344 
345 /* This overrides anything that was found in ohci_quirks[]. */
346 static int param_quirks;
347 module_param_named(quirks, param_quirks, int, 0644);
348 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
349 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
350 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
351 	", AR/selfID endianness = "	__stringify(QUIRK_BE_HEADERS)
352 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
353 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
354 	", TI SLLZ059 erratum = "	__stringify(QUIRK_TI_SLLZ059)
355 	", IR wake unreliable = "	__stringify(QUIRK_IR_WAKE)
356 	", phy LCtrl timeout = "	__stringify(QUIRK_PHY_LCTRL_TIMEOUT)
357 	")");
358 
359 #define OHCI_PARAM_DEBUG_AT_AR		1
360 #define OHCI_PARAM_DEBUG_SELFIDS	2
361 #define OHCI_PARAM_DEBUG_IRQS		4
362 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
363 
364 static int param_debug;
365 module_param_named(debug, param_debug, int, 0644);
366 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
367 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
368 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
369 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
370 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
371 	", or a combination, or all = -1)");
372 
373 static bool param_remote_dma;
374 module_param_named(remote_dma, param_remote_dma, bool, 0444);
375 MODULE_PARM_DESC(remote_dma, "Enable unfiltered remote DMA (default = N)");
376 
377 static void log_irqs(struct fw_ohci *ohci, u32 evt)
378 {
379 	if (likely(!(param_debug &
380 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
381 		return;
382 
383 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
384 	    !(evt & OHCI1394_busReset))
385 		return;
386 
387 	ohci_notice(ohci, "IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
388 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
389 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
390 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
391 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
392 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
393 	    evt & OHCI1394_isochRx		? " IR"			: "",
394 	    evt & OHCI1394_isochTx		? " IT"			: "",
395 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
396 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
397 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
398 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
399 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
400 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
401 	    evt & OHCI1394_busReset		? " busReset"		: "",
402 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
403 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
404 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
405 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
406 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
407 		    OHCI1394_cycleInconsistent |
408 		    OHCI1394_regAccessFail | OHCI1394_busReset)
409 						? " ?"			: "");
410 }
411 
412 static const char *speed[] = {
413 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
414 };
415 static const char *power[] = {
416 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
417 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
418 };
419 static const char port[] = { '.', '-', 'p', 'c', };
420 
421 static char _p(u32 *s, int shift)
422 {
423 	return port[*s >> shift & 3];
424 }
425 
426 static void log_selfids(struct fw_ohci *ohci, int generation, int self_id_count)
427 {
428 	u32 *s;
429 
430 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
431 		return;
432 
433 	ohci_notice(ohci, "%d selfIDs, generation %d, local node ID %04x\n",
434 		    self_id_count, generation, ohci->node_id);
435 
436 	for (s = ohci->self_id_buffer; self_id_count--; ++s)
437 		if ((*s & 1 << 23) == 0)
438 			ohci_notice(ohci,
439 			    "selfID 0: %08x, phy %d [%c%c%c] %s gc=%d %s %s%s%s\n",
440 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
441 			    speed[*s >> 14 & 3], *s >> 16 & 63,
442 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
443 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
444 		else
445 			ohci_notice(ohci,
446 			    "selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
447 			    *s, *s >> 24 & 63,
448 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
449 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
450 }
451 
452 static const char *evts[] = {
453 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
454 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
455 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
456 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
457 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
458 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
459 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
460 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
461 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
462 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
463 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
464 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
465 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
466 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
467 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
468 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
469 	[0x20] = "pending/cancelled",
470 };
471 static const char *tcodes[] = {
472 	[0x0] = "QW req",		[0x1] = "BW req",
473 	[0x2] = "W resp",		[0x3] = "-reserved-",
474 	[0x4] = "QR req",		[0x5] = "BR req",
475 	[0x6] = "QR resp",		[0x7] = "BR resp",
476 	[0x8] = "cycle start",		[0x9] = "Lk req",
477 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
478 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
479 	[0xe] = "link internal",	[0xf] = "-reserved-",
480 };
481 
482 static void log_ar_at_event(struct fw_ohci *ohci,
483 			    char dir, int speed, u32 *header, int evt)
484 {
485 	int tcode = header[0] >> 4 & 0xf;
486 	char specific[12];
487 
488 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
489 		return;
490 
491 	if (unlikely(evt >= ARRAY_SIZE(evts)))
492 			evt = 0x1f;
493 
494 	if (evt == OHCI1394_evt_bus_reset) {
495 		ohci_notice(ohci, "A%c evt_bus_reset, generation %d\n",
496 			    dir, (header[2] >> 16) & 0xff);
497 		return;
498 	}
499 
500 	switch (tcode) {
501 	case 0x0: case 0x6: case 0x8:
502 		snprintf(specific, sizeof(specific), " = %08x",
503 			 be32_to_cpu((__force __be32)header[3]));
504 		break;
505 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
506 		snprintf(specific, sizeof(specific), " %x,%x",
507 			 header[3] >> 16, header[3] & 0xffff);
508 		break;
509 	default:
510 		specific[0] = '\0';
511 	}
512 
513 	switch (tcode) {
514 	case 0xa:
515 		ohci_notice(ohci, "A%c %s, %s\n",
516 			    dir, evts[evt], tcodes[tcode]);
517 		break;
518 	case 0xe:
519 		ohci_notice(ohci, "A%c %s, PHY %08x %08x\n",
520 			    dir, evts[evt], header[1], header[2]);
521 		break;
522 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
523 		ohci_notice(ohci,
524 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s, %04x%08x%s\n",
525 			    dir, speed, header[0] >> 10 & 0x3f,
526 			    header[1] >> 16, header[0] >> 16, evts[evt],
527 			    tcodes[tcode], header[1] & 0xffff, header[2], specific);
528 		break;
529 	default:
530 		ohci_notice(ohci,
531 			    "A%c spd %x tl %02x, %04x -> %04x, %s, %s%s\n",
532 			    dir, speed, header[0] >> 10 & 0x3f,
533 			    header[1] >> 16, header[0] >> 16, evts[evt],
534 			    tcodes[tcode], specific);
535 	}
536 }
537 
538 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
539 {
540 	writel(data, ohci->registers + offset);
541 }
542 
543 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
544 {
545 	return readl(ohci->registers + offset);
546 }
547 
548 static inline void flush_writes(const struct fw_ohci *ohci)
549 {
550 	/* Do a dummy read to flush writes. */
551 	reg_read(ohci, OHCI1394_Version);
552 }
553 
554 /*
555  * Beware!  read_phy_reg(), write_phy_reg(), update_phy_reg(), and
556  * read_paged_phy_reg() require the caller to hold ohci->phy_reg_mutex.
557  * In other words, only use ohci_read_phy_reg() and ohci_update_phy_reg()
558  * directly.  Exceptions are intrinsically serialized contexts like pci_probe.
559  */
560 static int read_phy_reg(struct fw_ohci *ohci, int addr)
561 {
562 	u32 val;
563 	int i;
564 
565 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
566 	for (i = 0; i < 3 + 100; i++) {
567 		val = reg_read(ohci, OHCI1394_PhyControl);
568 		if (!~val)
569 			return -ENODEV; /* Card was ejected. */
570 
571 		if (val & OHCI1394_PhyControl_ReadDone)
572 			return OHCI1394_PhyControl_ReadData(val);
573 
574 		/*
575 		 * Try a few times without waiting.  Sleeping is necessary
576 		 * only when the link/PHY interface is busy.
577 		 */
578 		if (i >= 3)
579 			msleep(1);
580 	}
581 	ohci_err(ohci, "failed to read phy reg %d\n", addr);
582 	dump_stack();
583 
584 	return -EBUSY;
585 }
586 
587 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
588 {
589 	int i;
590 
591 	reg_write(ohci, OHCI1394_PhyControl,
592 		  OHCI1394_PhyControl_Write(addr, val));
593 	for (i = 0; i < 3 + 100; i++) {
594 		val = reg_read(ohci, OHCI1394_PhyControl);
595 		if (!~val)
596 			return -ENODEV; /* Card was ejected. */
597 
598 		if (!(val & OHCI1394_PhyControl_WritePending))
599 			return 0;
600 
601 		if (i >= 3)
602 			msleep(1);
603 	}
604 	ohci_err(ohci, "failed to write phy reg %d, val %u\n", addr, val);
605 	dump_stack();
606 
607 	return -EBUSY;
608 }
609 
610 static int update_phy_reg(struct fw_ohci *ohci, int addr,
611 			  int clear_bits, int set_bits)
612 {
613 	int ret = read_phy_reg(ohci, addr);
614 	if (ret < 0)
615 		return ret;
616 
617 	/*
618 	 * The interrupt status bits are cleared by writing a one bit.
619 	 * Avoid clearing them unless explicitly requested in set_bits.
620 	 */
621 	if (addr == 5)
622 		clear_bits |= PHY_INT_STATUS_BITS;
623 
624 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
625 }
626 
627 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
628 {
629 	int ret;
630 
631 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
632 	if (ret < 0)
633 		return ret;
634 
635 	return read_phy_reg(ohci, addr);
636 }
637 
638 static int ohci_read_phy_reg(struct fw_card *card, int addr)
639 {
640 	struct fw_ohci *ohci = fw_ohci(card);
641 	int ret;
642 
643 	mutex_lock(&ohci->phy_reg_mutex);
644 	ret = read_phy_reg(ohci, addr);
645 	mutex_unlock(&ohci->phy_reg_mutex);
646 
647 	return ret;
648 }
649 
650 static int ohci_update_phy_reg(struct fw_card *card, int addr,
651 			       int clear_bits, int set_bits)
652 {
653 	struct fw_ohci *ohci = fw_ohci(card);
654 	int ret;
655 
656 	mutex_lock(&ohci->phy_reg_mutex);
657 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
658 	mutex_unlock(&ohci->phy_reg_mutex);
659 
660 	return ret;
661 }
662 
663 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
664 {
665 	return page_private(ctx->pages[i]);
666 }
667 
668 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
669 {
670 	struct descriptor *d;
671 
672 	d = &ctx->descriptors[index];
673 	d->branch_address  &= cpu_to_le32(~0xf);
674 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
675 	d->transfer_status =  0;
676 
677 	wmb(); /* finish init of new descriptors before branch_address update */
678 	d = &ctx->descriptors[ctx->last_buffer_index];
679 	d->branch_address  |= cpu_to_le32(1);
680 
681 	ctx->last_buffer_index = index;
682 
683 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
684 }
685 
686 static void ar_context_release(struct ar_context *ctx)
687 {
688 	unsigned int i;
689 
690 	if (ctx->buffer)
691 		vm_unmap_ram(ctx->buffer, AR_BUFFERS + AR_WRAPAROUND_PAGES);
692 
693 	for (i = 0; i < AR_BUFFERS; i++)
694 		if (ctx->pages[i]) {
695 			dma_unmap_page(ctx->ohci->card.device,
696 				       ar_buffer_bus(ctx, i),
697 				       PAGE_SIZE, DMA_FROM_DEVICE);
698 			__free_page(ctx->pages[i]);
699 		}
700 }
701 
702 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
703 {
704 	struct fw_ohci *ohci = ctx->ohci;
705 
706 	if (reg_read(ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
707 		reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
708 		flush_writes(ohci);
709 
710 		ohci_err(ohci, "AR error: %s; DMA stopped\n", error_msg);
711 	}
712 	/* FIXME: restart? */
713 }
714 
715 static inline unsigned int ar_next_buffer_index(unsigned int index)
716 {
717 	return (index + 1) % AR_BUFFERS;
718 }
719 
720 static inline unsigned int ar_prev_buffer_index(unsigned int index)
721 {
722 	return (index - 1 + AR_BUFFERS) % AR_BUFFERS;
723 }
724 
725 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
726 {
727 	return ar_next_buffer_index(ctx->last_buffer_index);
728 }
729 
730 /*
731  * We search for the buffer that contains the last AR packet DMA data written
732  * by the controller.
733  */
734 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
735 						 unsigned int *buffer_offset)
736 {
737 	unsigned int i, next_i, last = ctx->last_buffer_index;
738 	__le16 res_count, next_res_count;
739 
740 	i = ar_first_buffer_index(ctx);
741 	res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
742 
743 	/* A buffer that is not yet completely filled must be the last one. */
744 	while (i != last && res_count == 0) {
745 
746 		/* Peek at the next descriptor. */
747 		next_i = ar_next_buffer_index(i);
748 		rmb(); /* read descriptors in order */
749 		next_res_count = ACCESS_ONCE(
750 				ctx->descriptors[next_i].res_count);
751 		/*
752 		 * If the next descriptor is still empty, we must stop at this
753 		 * descriptor.
754 		 */
755 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
756 			/*
757 			 * The exception is when the DMA data for one packet is
758 			 * split over three buffers; in this case, the middle
759 			 * buffer's descriptor might be never updated by the
760 			 * controller and look still empty, and we have to peek
761 			 * at the third one.
762 			 */
763 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
764 				next_i = ar_next_buffer_index(next_i);
765 				rmb();
766 				next_res_count = ACCESS_ONCE(
767 					ctx->descriptors[next_i].res_count);
768 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
769 					goto next_buffer_is_active;
770 			}
771 
772 			break;
773 		}
774 
775 next_buffer_is_active:
776 		i = next_i;
777 		res_count = next_res_count;
778 	}
779 
780 	rmb(); /* read res_count before the DMA data */
781 
782 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
783 	if (*buffer_offset > PAGE_SIZE) {
784 		*buffer_offset = 0;
785 		ar_context_abort(ctx, "corrupted descriptor");
786 	}
787 
788 	return i;
789 }
790 
791 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
792 				    unsigned int end_buffer_index,
793 				    unsigned int end_buffer_offset)
794 {
795 	unsigned int i;
796 
797 	i = ar_first_buffer_index(ctx);
798 	while (i != end_buffer_index) {
799 		dma_sync_single_for_cpu(ctx->ohci->card.device,
800 					ar_buffer_bus(ctx, i),
801 					PAGE_SIZE, DMA_FROM_DEVICE);
802 		i = ar_next_buffer_index(i);
803 	}
804 	if (end_buffer_offset > 0)
805 		dma_sync_single_for_cpu(ctx->ohci->card.device,
806 					ar_buffer_bus(ctx, i),
807 					end_buffer_offset, DMA_FROM_DEVICE);
808 }
809 
810 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
811 #define cond_le32_to_cpu(v) \
812 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
813 #else
814 #define cond_le32_to_cpu(v) le32_to_cpu(v)
815 #endif
816 
817 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
818 {
819 	struct fw_ohci *ohci = ctx->ohci;
820 	struct fw_packet p;
821 	u32 status, length, tcode;
822 	int evt;
823 
824 	p.header[0] = cond_le32_to_cpu(buffer[0]);
825 	p.header[1] = cond_le32_to_cpu(buffer[1]);
826 	p.header[2] = cond_le32_to_cpu(buffer[2]);
827 
828 	tcode = (p.header[0] >> 4) & 0x0f;
829 	switch (tcode) {
830 	case TCODE_WRITE_QUADLET_REQUEST:
831 	case TCODE_READ_QUADLET_RESPONSE:
832 		p.header[3] = (__force __u32) buffer[3];
833 		p.header_length = 16;
834 		p.payload_length = 0;
835 		break;
836 
837 	case TCODE_READ_BLOCK_REQUEST :
838 		p.header[3] = cond_le32_to_cpu(buffer[3]);
839 		p.header_length = 16;
840 		p.payload_length = 0;
841 		break;
842 
843 	case TCODE_WRITE_BLOCK_REQUEST:
844 	case TCODE_READ_BLOCK_RESPONSE:
845 	case TCODE_LOCK_REQUEST:
846 	case TCODE_LOCK_RESPONSE:
847 		p.header[3] = cond_le32_to_cpu(buffer[3]);
848 		p.header_length = 16;
849 		p.payload_length = p.header[3] >> 16;
850 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
851 			ar_context_abort(ctx, "invalid packet length");
852 			return NULL;
853 		}
854 		break;
855 
856 	case TCODE_WRITE_RESPONSE:
857 	case TCODE_READ_QUADLET_REQUEST:
858 	case OHCI_TCODE_PHY_PACKET:
859 		p.header_length = 12;
860 		p.payload_length = 0;
861 		break;
862 
863 	default:
864 		ar_context_abort(ctx, "invalid tcode");
865 		return NULL;
866 	}
867 
868 	p.payload = (void *) buffer + p.header_length;
869 
870 	/* FIXME: What to do about evt_* errors? */
871 	length = (p.header_length + p.payload_length + 3) / 4;
872 	status = cond_le32_to_cpu(buffer[length]);
873 	evt    = (status >> 16) & 0x1f;
874 
875 	p.ack        = evt - 16;
876 	p.speed      = (status >> 21) & 0x7;
877 	p.timestamp  = status & 0xffff;
878 	p.generation = ohci->request_generation;
879 
880 	log_ar_at_event(ohci, 'R', p.speed, p.header, evt);
881 
882 	/*
883 	 * Several controllers, notably from NEC and VIA, forget to
884 	 * write ack_complete status at PHY packet reception.
885 	 */
886 	if (evt == OHCI1394_evt_no_status &&
887 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
888 		p.ack = ACK_COMPLETE;
889 
890 	/*
891 	 * The OHCI bus reset handler synthesizes a PHY packet with
892 	 * the new generation number when a bus reset happens (see
893 	 * section 8.4.2.3).  This helps us determine when a request
894 	 * was received and make sure we send the response in the same
895 	 * generation.  We only need this for requests; for responses
896 	 * we use the unique tlabel for finding the matching
897 	 * request.
898 	 *
899 	 * Alas some chips sometimes emit bus reset packets with a
900 	 * wrong generation.  We set the correct generation for these
901 	 * at a slightly incorrect time (in bus_reset_work).
902 	 */
903 	if (evt == OHCI1394_evt_bus_reset) {
904 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
905 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
906 	} else if (ctx == &ohci->ar_request_ctx) {
907 		fw_core_handle_request(&ohci->card, &p);
908 	} else {
909 		fw_core_handle_response(&ohci->card, &p);
910 	}
911 
912 	return buffer + length + 1;
913 }
914 
915 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
916 {
917 	void *next;
918 
919 	while (p < end) {
920 		next = handle_ar_packet(ctx, p);
921 		if (!next)
922 			return p;
923 		p = next;
924 	}
925 
926 	return p;
927 }
928 
929 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
930 {
931 	unsigned int i;
932 
933 	i = ar_first_buffer_index(ctx);
934 	while (i != end_buffer) {
935 		dma_sync_single_for_device(ctx->ohci->card.device,
936 					   ar_buffer_bus(ctx, i),
937 					   PAGE_SIZE, DMA_FROM_DEVICE);
938 		ar_context_link_page(ctx, i);
939 		i = ar_next_buffer_index(i);
940 	}
941 }
942 
943 static void ar_context_tasklet(unsigned long data)
944 {
945 	struct ar_context *ctx = (struct ar_context *)data;
946 	unsigned int end_buffer_index, end_buffer_offset;
947 	void *p, *end;
948 
949 	p = ctx->pointer;
950 	if (!p)
951 		return;
952 
953 	end_buffer_index = ar_search_last_active_buffer(ctx,
954 							&end_buffer_offset);
955 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
956 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
957 
958 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
959 		/*
960 		 * The filled part of the overall buffer wraps around; handle
961 		 * all packets up to the buffer end here.  If the last packet
962 		 * wraps around, its tail will be visible after the buffer end
963 		 * because the buffer start pages are mapped there again.
964 		 */
965 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
966 		p = handle_ar_packets(ctx, p, buffer_end);
967 		if (p < buffer_end)
968 			goto error;
969 		/* adjust p to point back into the actual buffer */
970 		p -= AR_BUFFERS * PAGE_SIZE;
971 	}
972 
973 	p = handle_ar_packets(ctx, p, end);
974 	if (p != end) {
975 		if (p > end)
976 			ar_context_abort(ctx, "inconsistent descriptor");
977 		goto error;
978 	}
979 
980 	ctx->pointer = p;
981 	ar_recycle_buffers(ctx, end_buffer_index);
982 
983 	return;
984 
985 error:
986 	ctx->pointer = NULL;
987 }
988 
989 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
990 			   unsigned int descriptors_offset, u32 regs)
991 {
992 	unsigned int i;
993 	dma_addr_t dma_addr;
994 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
995 	struct descriptor *d;
996 
997 	ctx->regs        = regs;
998 	ctx->ohci        = ohci;
999 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
1000 
1001 	for (i = 0; i < AR_BUFFERS; i++) {
1002 		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
1003 		if (!ctx->pages[i])
1004 			goto out_of_memory;
1005 		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
1006 					0, PAGE_SIZE, DMA_FROM_DEVICE);
1007 		if (dma_mapping_error(ohci->card.device, dma_addr)) {
1008 			__free_page(ctx->pages[i]);
1009 			ctx->pages[i] = NULL;
1010 			goto out_of_memory;
1011 		}
1012 		set_page_private(ctx->pages[i], dma_addr);
1013 	}
1014 
1015 	for (i = 0; i < AR_BUFFERS; i++)
1016 		pages[i]              = ctx->pages[i];
1017 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
1018 		pages[AR_BUFFERS + i] = ctx->pages[i];
1019 	ctx->buffer = vm_map_ram(pages, AR_BUFFERS + AR_WRAPAROUND_PAGES,
1020 				 -1, PAGE_KERNEL);
1021 	if (!ctx->buffer)
1022 		goto out_of_memory;
1023 
1024 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
1025 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
1026 
1027 	for (i = 0; i < AR_BUFFERS; i++) {
1028 		d = &ctx->descriptors[i];
1029 		d->req_count      = cpu_to_le16(PAGE_SIZE);
1030 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
1031 						DESCRIPTOR_STATUS |
1032 						DESCRIPTOR_BRANCH_ALWAYS);
1033 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
1034 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
1035 			ar_next_buffer_index(i) * sizeof(struct descriptor));
1036 	}
1037 
1038 	return 0;
1039 
1040 out_of_memory:
1041 	ar_context_release(ctx);
1042 
1043 	return -ENOMEM;
1044 }
1045 
1046 static void ar_context_run(struct ar_context *ctx)
1047 {
1048 	unsigned int i;
1049 
1050 	for (i = 0; i < AR_BUFFERS; i++)
1051 		ar_context_link_page(ctx, i);
1052 
1053 	ctx->pointer = ctx->buffer;
1054 
1055 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1056 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1057 }
1058 
1059 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1060 {
1061 	__le16 branch;
1062 
1063 	branch = d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS);
1064 
1065 	/* figure out which descriptor the branch address goes in */
1066 	if (z == 2 && branch == cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
1067 		return d;
1068 	else
1069 		return d + z - 1;
1070 }
1071 
1072 static void context_tasklet(unsigned long data)
1073 {
1074 	struct context *ctx = (struct context *) data;
1075 	struct descriptor *d, *last;
1076 	u32 address;
1077 	int z;
1078 	struct descriptor_buffer *desc;
1079 
1080 	desc = list_entry(ctx->buffer_list.next,
1081 			struct descriptor_buffer, list);
1082 	last = ctx->last;
1083 	while (last->branch_address != 0) {
1084 		struct descriptor_buffer *old_desc = desc;
1085 		address = le32_to_cpu(last->branch_address);
1086 		z = address & 0xf;
1087 		address &= ~0xf;
1088 		ctx->current_bus = address;
1089 
1090 		/* If the branch address points to a buffer outside of the
1091 		 * current buffer, advance to the next buffer. */
1092 		if (address < desc->buffer_bus ||
1093 				address >= desc->buffer_bus + desc->used)
1094 			desc = list_entry(desc->list.next,
1095 					struct descriptor_buffer, list);
1096 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1097 		last = find_branch_descriptor(d, z);
1098 
1099 		if (!ctx->callback(ctx, d, last))
1100 			break;
1101 
1102 		if (old_desc != desc) {
1103 			/* If we've advanced to the next buffer, move the
1104 			 * previous buffer to the free list. */
1105 			unsigned long flags;
1106 			old_desc->used = 0;
1107 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1108 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1109 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1110 		}
1111 		ctx->last = last;
1112 	}
1113 }
1114 
1115 /*
1116  * Allocate a new buffer and add it to the list of free buffers for this
1117  * context.  Must be called with ohci->lock held.
1118  */
1119 static int context_add_buffer(struct context *ctx)
1120 {
1121 	struct descriptor_buffer *desc;
1122 	dma_addr_t uninitialized_var(bus_addr);
1123 	int offset;
1124 
1125 	/*
1126 	 * 16MB of descriptors should be far more than enough for any DMA
1127 	 * program.  This will catch run-away userspace or DoS attacks.
1128 	 */
1129 	if (ctx->total_allocation >= 16*1024*1024)
1130 		return -ENOMEM;
1131 
1132 	desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1133 			&bus_addr, GFP_ATOMIC);
1134 	if (!desc)
1135 		return -ENOMEM;
1136 
1137 	offset = (void *)&desc->buffer - (void *)desc;
1138 	desc->buffer_size = PAGE_SIZE - offset;
1139 	desc->buffer_bus = bus_addr + offset;
1140 	desc->used = 0;
1141 
1142 	list_add_tail(&desc->list, &ctx->buffer_list);
1143 	ctx->total_allocation += PAGE_SIZE;
1144 
1145 	return 0;
1146 }
1147 
1148 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1149 			u32 regs, descriptor_callback_t callback)
1150 {
1151 	ctx->ohci = ohci;
1152 	ctx->regs = regs;
1153 	ctx->total_allocation = 0;
1154 
1155 	INIT_LIST_HEAD(&ctx->buffer_list);
1156 	if (context_add_buffer(ctx) < 0)
1157 		return -ENOMEM;
1158 
1159 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1160 			struct descriptor_buffer, list);
1161 
1162 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1163 	ctx->callback = callback;
1164 
1165 	/*
1166 	 * We put a dummy descriptor in the buffer that has a NULL
1167 	 * branch address and looks like it's been sent.  That way we
1168 	 * have a descriptor to append DMA programs to.
1169 	 */
1170 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1171 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1172 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1173 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1174 	ctx->last = ctx->buffer_tail->buffer;
1175 	ctx->prev = ctx->buffer_tail->buffer;
1176 	ctx->prev_z = 1;
1177 
1178 	return 0;
1179 }
1180 
1181 static void context_release(struct context *ctx)
1182 {
1183 	struct fw_card *card = &ctx->ohci->card;
1184 	struct descriptor_buffer *desc, *tmp;
1185 
1186 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1187 		dma_free_coherent(card->device, PAGE_SIZE, desc,
1188 			desc->buffer_bus -
1189 			((void *)&desc->buffer - (void *)desc));
1190 }
1191 
1192 /* Must be called with ohci->lock held */
1193 static struct descriptor *context_get_descriptors(struct context *ctx,
1194 						  int z, dma_addr_t *d_bus)
1195 {
1196 	struct descriptor *d = NULL;
1197 	struct descriptor_buffer *desc = ctx->buffer_tail;
1198 
1199 	if (z * sizeof(*d) > desc->buffer_size)
1200 		return NULL;
1201 
1202 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1203 		/* No room for the descriptor in this buffer, so advance to the
1204 		 * next one. */
1205 
1206 		if (desc->list.next == &ctx->buffer_list) {
1207 			/* If there is no free buffer next in the list,
1208 			 * allocate one. */
1209 			if (context_add_buffer(ctx) < 0)
1210 				return NULL;
1211 		}
1212 		desc = list_entry(desc->list.next,
1213 				struct descriptor_buffer, list);
1214 		ctx->buffer_tail = desc;
1215 	}
1216 
1217 	d = desc->buffer + desc->used / sizeof(*d);
1218 	memset(d, 0, z * sizeof(*d));
1219 	*d_bus = desc->buffer_bus + desc->used;
1220 
1221 	return d;
1222 }
1223 
1224 static void context_run(struct context *ctx, u32 extra)
1225 {
1226 	struct fw_ohci *ohci = ctx->ohci;
1227 
1228 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1229 		  le32_to_cpu(ctx->last->branch_address));
1230 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1231 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1232 	ctx->running = true;
1233 	flush_writes(ohci);
1234 }
1235 
1236 static void context_append(struct context *ctx,
1237 			   struct descriptor *d, int z, int extra)
1238 {
1239 	dma_addr_t d_bus;
1240 	struct descriptor_buffer *desc = ctx->buffer_tail;
1241 	struct descriptor *d_branch;
1242 
1243 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1244 
1245 	desc->used += (z + extra) * sizeof(*d);
1246 
1247 	wmb(); /* finish init of new descriptors before branch_address update */
1248 
1249 	d_branch = find_branch_descriptor(ctx->prev, ctx->prev_z);
1250 	d_branch->branch_address = cpu_to_le32(d_bus | z);
1251 
1252 	/*
1253 	 * VT6306 incorrectly checks only the single descriptor at the
1254 	 * CommandPtr when the wake bit is written, so if it's a
1255 	 * multi-descriptor block starting with an INPUT_MORE, put a copy of
1256 	 * the branch address in the first descriptor.
1257 	 *
1258 	 * Not doing this for transmit contexts since not sure how it interacts
1259 	 * with skip addresses.
1260 	 */
1261 	if (unlikely(ctx->ohci->quirks & QUIRK_IR_WAKE) &&
1262 	    d_branch != ctx->prev &&
1263 	    (ctx->prev->control & cpu_to_le16(DESCRIPTOR_CMD)) ==
1264 	     cpu_to_le16(DESCRIPTOR_INPUT_MORE)) {
1265 		ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1266 	}
1267 
1268 	ctx->prev = d;
1269 	ctx->prev_z = z;
1270 }
1271 
1272 static void context_stop(struct context *ctx)
1273 {
1274 	struct fw_ohci *ohci = ctx->ohci;
1275 	u32 reg;
1276 	int i;
1277 
1278 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1279 	ctx->running = false;
1280 
1281 	for (i = 0; i < 1000; i++) {
1282 		reg = reg_read(ohci, CONTROL_SET(ctx->regs));
1283 		if ((reg & CONTEXT_ACTIVE) == 0)
1284 			return;
1285 
1286 		if (i)
1287 			udelay(10);
1288 	}
1289 	ohci_err(ohci, "DMA context still active (0x%08x)\n", reg);
1290 }
1291 
1292 struct driver_data {
1293 	u8 inline_data[8];
1294 	struct fw_packet *packet;
1295 };
1296 
1297 /*
1298  * This function apppends a packet to the DMA queue for transmission.
1299  * Must always be called with the ochi->lock held to ensure proper
1300  * generation handling and locking around packet queue manipulation.
1301  */
1302 static int at_context_queue_packet(struct context *ctx,
1303 				   struct fw_packet *packet)
1304 {
1305 	struct fw_ohci *ohci = ctx->ohci;
1306 	dma_addr_t d_bus, uninitialized_var(payload_bus);
1307 	struct driver_data *driver_data;
1308 	struct descriptor *d, *last;
1309 	__le32 *header;
1310 	int z, tcode;
1311 
1312 	d = context_get_descriptors(ctx, 4, &d_bus);
1313 	if (d == NULL) {
1314 		packet->ack = RCODE_SEND_ERROR;
1315 		return -1;
1316 	}
1317 
1318 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1319 	d[0].res_count = cpu_to_le16(packet->timestamp);
1320 
1321 	/*
1322 	 * The DMA format for asynchronous link packets is different
1323 	 * from the IEEE1394 layout, so shift the fields around
1324 	 * accordingly.
1325 	 */
1326 
1327 	tcode = (packet->header[0] >> 4) & 0x0f;
1328 	header = (__le32 *) &d[1];
1329 	switch (tcode) {
1330 	case TCODE_WRITE_QUADLET_REQUEST:
1331 	case TCODE_WRITE_BLOCK_REQUEST:
1332 	case TCODE_WRITE_RESPONSE:
1333 	case TCODE_READ_QUADLET_REQUEST:
1334 	case TCODE_READ_BLOCK_REQUEST:
1335 	case TCODE_READ_QUADLET_RESPONSE:
1336 	case TCODE_READ_BLOCK_RESPONSE:
1337 	case TCODE_LOCK_REQUEST:
1338 	case TCODE_LOCK_RESPONSE:
1339 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1340 					(packet->speed << 16));
1341 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1342 					(packet->header[0] & 0xffff0000));
1343 		header[2] = cpu_to_le32(packet->header[2]);
1344 
1345 		if (TCODE_IS_BLOCK_PACKET(tcode))
1346 			header[3] = cpu_to_le32(packet->header[3]);
1347 		else
1348 			header[3] = (__force __le32) packet->header[3];
1349 
1350 		d[0].req_count = cpu_to_le16(packet->header_length);
1351 		break;
1352 
1353 	case TCODE_LINK_INTERNAL:
1354 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1355 					(packet->speed << 16));
1356 		header[1] = cpu_to_le32(packet->header[1]);
1357 		header[2] = cpu_to_le32(packet->header[2]);
1358 		d[0].req_count = cpu_to_le16(12);
1359 
1360 		if (is_ping_packet(&packet->header[1]))
1361 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1362 		break;
1363 
1364 	case TCODE_STREAM_DATA:
1365 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1366 					(packet->speed << 16));
1367 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1368 		d[0].req_count = cpu_to_le16(8);
1369 		break;
1370 
1371 	default:
1372 		/* BUG(); */
1373 		packet->ack = RCODE_SEND_ERROR;
1374 		return -1;
1375 	}
1376 
1377 	BUILD_BUG_ON(sizeof(struct driver_data) > sizeof(struct descriptor));
1378 	driver_data = (struct driver_data *) &d[3];
1379 	driver_data->packet = packet;
1380 	packet->driver_data = driver_data;
1381 
1382 	if (packet->payload_length > 0) {
1383 		if (packet->payload_length > sizeof(driver_data->inline_data)) {
1384 			payload_bus = dma_map_single(ohci->card.device,
1385 						     packet->payload,
1386 						     packet->payload_length,
1387 						     DMA_TO_DEVICE);
1388 			if (dma_mapping_error(ohci->card.device, payload_bus)) {
1389 				packet->ack = RCODE_SEND_ERROR;
1390 				return -1;
1391 			}
1392 			packet->payload_bus	= payload_bus;
1393 			packet->payload_mapped	= true;
1394 		} else {
1395 			memcpy(driver_data->inline_data, packet->payload,
1396 			       packet->payload_length);
1397 			payload_bus = d_bus + 3 * sizeof(*d);
1398 		}
1399 
1400 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1401 		d[2].data_address = cpu_to_le32(payload_bus);
1402 		last = &d[2];
1403 		z = 3;
1404 	} else {
1405 		last = &d[0];
1406 		z = 2;
1407 	}
1408 
1409 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1410 				     DESCRIPTOR_IRQ_ALWAYS |
1411 				     DESCRIPTOR_BRANCH_ALWAYS);
1412 
1413 	/* FIXME: Document how the locking works. */
1414 	if (ohci->generation != packet->generation) {
1415 		if (packet->payload_mapped)
1416 			dma_unmap_single(ohci->card.device, payload_bus,
1417 					 packet->payload_length, DMA_TO_DEVICE);
1418 		packet->ack = RCODE_GENERATION;
1419 		return -1;
1420 	}
1421 
1422 	context_append(ctx, d, z, 4 - z);
1423 
1424 	if (ctx->running)
1425 		reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1426 	else
1427 		context_run(ctx, 0);
1428 
1429 	return 0;
1430 }
1431 
1432 static void at_context_flush(struct context *ctx)
1433 {
1434 	tasklet_disable(&ctx->tasklet);
1435 
1436 	ctx->flushing = true;
1437 	context_tasklet((unsigned long)ctx);
1438 	ctx->flushing = false;
1439 
1440 	tasklet_enable(&ctx->tasklet);
1441 }
1442 
1443 static int handle_at_packet(struct context *context,
1444 			    struct descriptor *d,
1445 			    struct descriptor *last)
1446 {
1447 	struct driver_data *driver_data;
1448 	struct fw_packet *packet;
1449 	struct fw_ohci *ohci = context->ohci;
1450 	int evt;
1451 
1452 	if (last->transfer_status == 0 && !context->flushing)
1453 		/* This descriptor isn't done yet, stop iteration. */
1454 		return 0;
1455 
1456 	driver_data = (struct driver_data *) &d[3];
1457 	packet = driver_data->packet;
1458 	if (packet == NULL)
1459 		/* This packet was cancelled, just continue. */
1460 		return 1;
1461 
1462 	if (packet->payload_mapped)
1463 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1464 				 packet->payload_length, DMA_TO_DEVICE);
1465 
1466 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1467 	packet->timestamp = le16_to_cpu(last->res_count);
1468 
1469 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, evt);
1470 
1471 	switch (evt) {
1472 	case OHCI1394_evt_timeout:
1473 		/* Async response transmit timed out. */
1474 		packet->ack = RCODE_CANCELLED;
1475 		break;
1476 
1477 	case OHCI1394_evt_flushed:
1478 		/*
1479 		 * The packet was flushed should give same error as
1480 		 * when we try to use a stale generation count.
1481 		 */
1482 		packet->ack = RCODE_GENERATION;
1483 		break;
1484 
1485 	case OHCI1394_evt_missing_ack:
1486 		if (context->flushing)
1487 			packet->ack = RCODE_GENERATION;
1488 		else {
1489 			/*
1490 			 * Using a valid (current) generation count, but the
1491 			 * node is not on the bus or not sending acks.
1492 			 */
1493 			packet->ack = RCODE_NO_ACK;
1494 		}
1495 		break;
1496 
1497 	case ACK_COMPLETE + 0x10:
1498 	case ACK_PENDING + 0x10:
1499 	case ACK_BUSY_X + 0x10:
1500 	case ACK_BUSY_A + 0x10:
1501 	case ACK_BUSY_B + 0x10:
1502 	case ACK_DATA_ERROR + 0x10:
1503 	case ACK_TYPE_ERROR + 0x10:
1504 		packet->ack = evt - 0x10;
1505 		break;
1506 
1507 	case OHCI1394_evt_no_status:
1508 		if (context->flushing) {
1509 			packet->ack = RCODE_GENERATION;
1510 			break;
1511 		}
1512 		/* fall through */
1513 
1514 	default:
1515 		packet->ack = RCODE_SEND_ERROR;
1516 		break;
1517 	}
1518 
1519 	packet->callback(packet, &ohci->card, packet->ack);
1520 
1521 	return 1;
1522 }
1523 
1524 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1525 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1526 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1527 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1528 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
1529 
1530 static void handle_local_rom(struct fw_ohci *ohci,
1531 			     struct fw_packet *packet, u32 csr)
1532 {
1533 	struct fw_packet response;
1534 	int tcode, length, i;
1535 
1536 	tcode = HEADER_GET_TCODE(packet->header[0]);
1537 	if (TCODE_IS_BLOCK_PACKET(tcode))
1538 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1539 	else
1540 		length = 4;
1541 
1542 	i = csr - CSR_CONFIG_ROM;
1543 	if (i + length > CONFIG_ROM_SIZE) {
1544 		fw_fill_response(&response, packet->header,
1545 				 RCODE_ADDRESS_ERROR, NULL, 0);
1546 	} else if (!TCODE_IS_READ_REQUEST(tcode)) {
1547 		fw_fill_response(&response, packet->header,
1548 				 RCODE_TYPE_ERROR, NULL, 0);
1549 	} else {
1550 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1551 				 (void *) ohci->config_rom + i, length);
1552 	}
1553 
1554 	fw_core_handle_response(&ohci->card, &response);
1555 }
1556 
1557 static void handle_local_lock(struct fw_ohci *ohci,
1558 			      struct fw_packet *packet, u32 csr)
1559 {
1560 	struct fw_packet response;
1561 	int tcode, length, ext_tcode, sel, try;
1562 	__be32 *payload, lock_old;
1563 	u32 lock_arg, lock_data;
1564 
1565 	tcode = HEADER_GET_TCODE(packet->header[0]);
1566 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1567 	payload = packet->payload;
1568 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1569 
1570 	if (tcode == TCODE_LOCK_REQUEST &&
1571 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1572 		lock_arg = be32_to_cpu(payload[0]);
1573 		lock_data = be32_to_cpu(payload[1]);
1574 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1575 		lock_arg = 0;
1576 		lock_data = 0;
1577 	} else {
1578 		fw_fill_response(&response, packet->header,
1579 				 RCODE_TYPE_ERROR, NULL, 0);
1580 		goto out;
1581 	}
1582 
1583 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1584 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1585 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1586 	reg_write(ohci, OHCI1394_CSRControl, sel);
1587 
1588 	for (try = 0; try < 20; try++)
1589 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1590 			lock_old = cpu_to_be32(reg_read(ohci,
1591 							OHCI1394_CSRData));
1592 			fw_fill_response(&response, packet->header,
1593 					 RCODE_COMPLETE,
1594 					 &lock_old, sizeof(lock_old));
1595 			goto out;
1596 		}
1597 
1598 	ohci_err(ohci, "swap not done (CSR lock timeout)\n");
1599 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1600 
1601  out:
1602 	fw_core_handle_response(&ohci->card, &response);
1603 }
1604 
1605 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1606 {
1607 	u64 offset, csr;
1608 
1609 	if (ctx == &ctx->ohci->at_request_ctx) {
1610 		packet->ack = ACK_PENDING;
1611 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1612 	}
1613 
1614 	offset =
1615 		((unsigned long long)
1616 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1617 		packet->header[2];
1618 	csr = offset - CSR_REGISTER_BASE;
1619 
1620 	/* Handle config rom reads. */
1621 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1622 		handle_local_rom(ctx->ohci, packet, csr);
1623 	else switch (csr) {
1624 	case CSR_BUS_MANAGER_ID:
1625 	case CSR_BANDWIDTH_AVAILABLE:
1626 	case CSR_CHANNELS_AVAILABLE_HI:
1627 	case CSR_CHANNELS_AVAILABLE_LO:
1628 		handle_local_lock(ctx->ohci, packet, csr);
1629 		break;
1630 	default:
1631 		if (ctx == &ctx->ohci->at_request_ctx)
1632 			fw_core_handle_request(&ctx->ohci->card, packet);
1633 		else
1634 			fw_core_handle_response(&ctx->ohci->card, packet);
1635 		break;
1636 	}
1637 
1638 	if (ctx == &ctx->ohci->at_response_ctx) {
1639 		packet->ack = ACK_COMPLETE;
1640 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1641 	}
1642 }
1643 
1644 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1645 {
1646 	unsigned long flags;
1647 	int ret;
1648 
1649 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1650 
1651 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1652 	    ctx->ohci->generation == packet->generation) {
1653 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1654 		handle_local_request(ctx, packet);
1655 		return;
1656 	}
1657 
1658 	ret = at_context_queue_packet(ctx, packet);
1659 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1660 
1661 	if (ret < 0)
1662 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1663 
1664 }
1665 
1666 static void detect_dead_context(struct fw_ohci *ohci,
1667 				const char *name, unsigned int regs)
1668 {
1669 	u32 ctl;
1670 
1671 	ctl = reg_read(ohci, CONTROL_SET(regs));
1672 	if (ctl & CONTEXT_DEAD)
1673 		ohci_err(ohci, "DMA context %s has stopped, error code: %s\n",
1674 			name, evts[ctl & 0x1f]);
1675 }
1676 
1677 static void handle_dead_contexts(struct fw_ohci *ohci)
1678 {
1679 	unsigned int i;
1680 	char name[8];
1681 
1682 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1683 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1684 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1685 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1686 	for (i = 0; i < 32; ++i) {
1687 		if (!(ohci->it_context_support & (1 << i)))
1688 			continue;
1689 		sprintf(name, "IT%u", i);
1690 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1691 	}
1692 	for (i = 0; i < 32; ++i) {
1693 		if (!(ohci->ir_context_support & (1 << i)))
1694 			continue;
1695 		sprintf(name, "IR%u", i);
1696 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1697 	}
1698 	/* TODO: maybe try to flush and restart the dead contexts */
1699 }
1700 
1701 static u32 cycle_timer_ticks(u32 cycle_timer)
1702 {
1703 	u32 ticks;
1704 
1705 	ticks = cycle_timer & 0xfff;
1706 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1707 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1708 
1709 	return ticks;
1710 }
1711 
1712 /*
1713  * Some controllers exhibit one or more of the following bugs when updating the
1714  * iso cycle timer register:
1715  *  - When the lowest six bits are wrapping around to zero, a read that happens
1716  *    at the same time will return garbage in the lowest ten bits.
1717  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1718  *    not incremented for about 60 ns.
1719  *  - Occasionally, the entire register reads zero.
1720  *
1721  * To catch these, we read the register three times and ensure that the
1722  * difference between each two consecutive reads is approximately the same, i.e.
1723  * less than twice the other.  Furthermore, any negative difference indicates an
1724  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1725  * execute, so we have enough precision to compute the ratio of the differences.)
1726  */
1727 static u32 get_cycle_time(struct fw_ohci *ohci)
1728 {
1729 	u32 c0, c1, c2;
1730 	u32 t0, t1, t2;
1731 	s32 diff01, diff12;
1732 	int i;
1733 
1734 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1735 
1736 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1737 		i = 0;
1738 		c1 = c2;
1739 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1740 		do {
1741 			c0 = c1;
1742 			c1 = c2;
1743 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1744 			t0 = cycle_timer_ticks(c0);
1745 			t1 = cycle_timer_ticks(c1);
1746 			t2 = cycle_timer_ticks(c2);
1747 			diff01 = t1 - t0;
1748 			diff12 = t2 - t1;
1749 		} while ((diff01 <= 0 || diff12 <= 0 ||
1750 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1751 			 && i++ < 20);
1752 	}
1753 
1754 	return c2;
1755 }
1756 
1757 /*
1758  * This function has to be called at least every 64 seconds.  The bus_time
1759  * field stores not only the upper 25 bits of the BUS_TIME register but also
1760  * the most significant bit of the cycle timer in bit 6 so that we can detect
1761  * changes in this bit.
1762  */
1763 static u32 update_bus_time(struct fw_ohci *ohci)
1764 {
1765 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1766 
1767 	if (unlikely(!ohci->bus_time_running)) {
1768 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_cycle64Seconds);
1769 		ohci->bus_time = (lower_32_bits(get_seconds()) & ~0x7f) |
1770 		                 (cycle_time_seconds & 0x40);
1771 		ohci->bus_time_running = true;
1772 	}
1773 
1774 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1775 		ohci->bus_time += 0x40;
1776 
1777 	return ohci->bus_time | cycle_time_seconds;
1778 }
1779 
1780 static int get_status_for_port(struct fw_ohci *ohci, int port_index)
1781 {
1782 	int reg;
1783 
1784 	mutex_lock(&ohci->phy_reg_mutex);
1785 	reg = write_phy_reg(ohci, 7, port_index);
1786 	if (reg >= 0)
1787 		reg = read_phy_reg(ohci, 8);
1788 	mutex_unlock(&ohci->phy_reg_mutex);
1789 	if (reg < 0)
1790 		return reg;
1791 
1792 	switch (reg & 0x0f) {
1793 	case 0x06:
1794 		return 2;	/* is child node (connected to parent node) */
1795 	case 0x0e:
1796 		return 3;	/* is parent node (connected to child node) */
1797 	}
1798 	return 1;		/* not connected */
1799 }
1800 
1801 static int get_self_id_pos(struct fw_ohci *ohci, u32 self_id,
1802 	int self_id_count)
1803 {
1804 	int i;
1805 	u32 entry;
1806 
1807 	for (i = 0; i < self_id_count; i++) {
1808 		entry = ohci->self_id_buffer[i];
1809 		if ((self_id & 0xff000000) == (entry & 0xff000000))
1810 			return -1;
1811 		if ((self_id & 0xff000000) < (entry & 0xff000000))
1812 			return i;
1813 	}
1814 	return i;
1815 }
1816 
1817 static int initiated_reset(struct fw_ohci *ohci)
1818 {
1819 	int reg;
1820 	int ret = 0;
1821 
1822 	mutex_lock(&ohci->phy_reg_mutex);
1823 	reg = write_phy_reg(ohci, 7, 0xe0); /* Select page 7 */
1824 	if (reg >= 0) {
1825 		reg = read_phy_reg(ohci, 8);
1826 		reg |= 0x40;
1827 		reg = write_phy_reg(ohci, 8, reg); /* set PMODE bit */
1828 		if (reg >= 0) {
1829 			reg = read_phy_reg(ohci, 12); /* read register 12 */
1830 			if (reg >= 0) {
1831 				if ((reg & 0x08) == 0x08) {
1832 					/* bit 3 indicates "initiated reset" */
1833 					ret = 0x2;
1834 				}
1835 			}
1836 		}
1837 	}
1838 	mutex_unlock(&ohci->phy_reg_mutex);
1839 	return ret;
1840 }
1841 
1842 /*
1843  * TI TSB82AA2B and TSB12LV26 do not receive the selfID of a locally
1844  * attached TSB41BA3D phy; see http://www.ti.com/litv/pdf/sllz059.
1845  * Construct the selfID from phy register contents.
1846  */
1847 static int find_and_insert_self_id(struct fw_ohci *ohci, int self_id_count)
1848 {
1849 	int reg, i, pos, status;
1850 	/* link active 1, speed 3, bridge 0, contender 1, more packets 0 */
1851 	u32 self_id = 0x8040c800;
1852 
1853 	reg = reg_read(ohci, OHCI1394_NodeID);
1854 	if (!(reg & OHCI1394_NodeID_idValid)) {
1855 		ohci_notice(ohci,
1856 			    "node ID not valid, new bus reset in progress\n");
1857 		return -EBUSY;
1858 	}
1859 	self_id |= ((reg & 0x3f) << 24); /* phy ID */
1860 
1861 	reg = ohci_read_phy_reg(&ohci->card, 4);
1862 	if (reg < 0)
1863 		return reg;
1864 	self_id |= ((reg & 0x07) << 8); /* power class */
1865 
1866 	reg = ohci_read_phy_reg(&ohci->card, 1);
1867 	if (reg < 0)
1868 		return reg;
1869 	self_id |= ((reg & 0x3f) << 16); /* gap count */
1870 
1871 	for (i = 0; i < 3; i++) {
1872 		status = get_status_for_port(ohci, i);
1873 		if (status < 0)
1874 			return status;
1875 		self_id |= ((status & 0x3) << (6 - (i * 2)));
1876 	}
1877 
1878 	self_id |= initiated_reset(ohci);
1879 
1880 	pos = get_self_id_pos(ohci, self_id, self_id_count);
1881 	if (pos >= 0) {
1882 		memmove(&(ohci->self_id_buffer[pos+1]),
1883 			&(ohci->self_id_buffer[pos]),
1884 			(self_id_count - pos) * sizeof(*ohci->self_id_buffer));
1885 		ohci->self_id_buffer[pos] = self_id;
1886 		self_id_count++;
1887 	}
1888 	return self_id_count;
1889 }
1890 
1891 static void bus_reset_work(struct work_struct *work)
1892 {
1893 	struct fw_ohci *ohci =
1894 		container_of(work, struct fw_ohci, bus_reset_work);
1895 	int self_id_count, generation, new_generation, i, j;
1896 	u32 reg;
1897 	void *free_rom = NULL;
1898 	dma_addr_t free_rom_bus = 0;
1899 	bool is_new_root;
1900 
1901 	reg = reg_read(ohci, OHCI1394_NodeID);
1902 	if (!(reg & OHCI1394_NodeID_idValid)) {
1903 		ohci_notice(ohci,
1904 			    "node ID not valid, new bus reset in progress\n");
1905 		return;
1906 	}
1907 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1908 		ohci_notice(ohci, "malconfigured bus\n");
1909 		return;
1910 	}
1911 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1912 			       OHCI1394_NodeID_nodeNumber);
1913 
1914 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1915 	if (!(ohci->is_root && is_new_root))
1916 		reg_write(ohci, OHCI1394_LinkControlSet,
1917 			  OHCI1394_LinkControl_cycleMaster);
1918 	ohci->is_root = is_new_root;
1919 
1920 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1921 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1922 		ohci_notice(ohci, "self ID receive error\n");
1923 		return;
1924 	}
1925 	/*
1926 	 * The count in the SelfIDCount register is the number of
1927 	 * bytes in the self ID receive buffer.  Since we also receive
1928 	 * the inverted quadlets and a header quadlet, we shift one
1929 	 * bit extra to get the actual number of self IDs.
1930 	 */
1931 	self_id_count = (reg >> 3) & 0xff;
1932 
1933 	if (self_id_count > 252) {
1934 		ohci_notice(ohci, "bad selfIDSize (%08x)\n", reg);
1935 		return;
1936 	}
1937 
1938 	generation = (cond_le32_to_cpu(ohci->self_id[0]) >> 16) & 0xff;
1939 	rmb();
1940 
1941 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1942 		u32 id  = cond_le32_to_cpu(ohci->self_id[i]);
1943 		u32 id2 = cond_le32_to_cpu(ohci->self_id[i + 1]);
1944 
1945 		if (id != ~id2) {
1946 			/*
1947 			 * If the invalid data looks like a cycle start packet,
1948 			 * it's likely to be the result of the cycle master
1949 			 * having a wrong gap count.  In this case, the self IDs
1950 			 * so far are valid and should be processed so that the
1951 			 * bus manager can then correct the gap count.
1952 			 */
1953 			if (id == 0xffff008f) {
1954 				ohci_notice(ohci, "ignoring spurious self IDs\n");
1955 				self_id_count = j;
1956 				break;
1957 			}
1958 
1959 			ohci_notice(ohci, "bad self ID %d/%d (%08x != ~%08x)\n",
1960 				    j, self_id_count, id, id2);
1961 			return;
1962 		}
1963 		ohci->self_id_buffer[j] = id;
1964 	}
1965 
1966 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
1967 		self_id_count = find_and_insert_self_id(ohci, self_id_count);
1968 		if (self_id_count < 0) {
1969 			ohci_notice(ohci,
1970 				    "could not construct local self ID\n");
1971 			return;
1972 		}
1973 	}
1974 
1975 	if (self_id_count == 0) {
1976 		ohci_notice(ohci, "no self IDs\n");
1977 		return;
1978 	}
1979 	rmb();
1980 
1981 	/*
1982 	 * Check the consistency of the self IDs we just read.  The
1983 	 * problem we face is that a new bus reset can start while we
1984 	 * read out the self IDs from the DMA buffer. If this happens,
1985 	 * the DMA buffer will be overwritten with new self IDs and we
1986 	 * will read out inconsistent data.  The OHCI specification
1987 	 * (section 11.2) recommends a technique similar to
1988 	 * linux/seqlock.h, where we remember the generation of the
1989 	 * self IDs in the buffer before reading them out and compare
1990 	 * it to the current generation after reading them out.  If
1991 	 * the two generations match we know we have a consistent set
1992 	 * of self IDs.
1993 	 */
1994 
1995 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1996 	if (new_generation != generation) {
1997 		ohci_notice(ohci, "new bus reset, discarding self ids\n");
1998 		return;
1999 	}
2000 
2001 	/* FIXME: Document how the locking works. */
2002 	spin_lock_irq(&ohci->lock);
2003 
2004 	ohci->generation = -1; /* prevent AT packet queueing */
2005 	context_stop(&ohci->at_request_ctx);
2006 	context_stop(&ohci->at_response_ctx);
2007 
2008 	spin_unlock_irq(&ohci->lock);
2009 
2010 	/*
2011 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
2012 	 * packets in the AT queues and software needs to drain them.
2013 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
2014 	 */
2015 	at_context_flush(&ohci->at_request_ctx);
2016 	at_context_flush(&ohci->at_response_ctx);
2017 
2018 	spin_lock_irq(&ohci->lock);
2019 
2020 	ohci->generation = generation;
2021 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
2022 
2023 	if (ohci->quirks & QUIRK_RESET_PACKET)
2024 		ohci->request_generation = generation;
2025 
2026 	/*
2027 	 * This next bit is unrelated to the AT context stuff but we
2028 	 * have to do it under the spinlock also.  If a new config rom
2029 	 * was set up before this reset, the old one is now no longer
2030 	 * in use and we can free it. Update the config rom pointers
2031 	 * to point to the current config rom and clear the
2032 	 * next_config_rom pointer so a new update can take place.
2033 	 */
2034 
2035 	if (ohci->next_config_rom != NULL) {
2036 		if (ohci->next_config_rom != ohci->config_rom) {
2037 			free_rom      = ohci->config_rom;
2038 			free_rom_bus  = ohci->config_rom_bus;
2039 		}
2040 		ohci->config_rom      = ohci->next_config_rom;
2041 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
2042 		ohci->next_config_rom = NULL;
2043 
2044 		/*
2045 		 * Restore config_rom image and manually update
2046 		 * config_rom registers.  Writing the header quadlet
2047 		 * will indicate that the config rom is ready, so we
2048 		 * do that last.
2049 		 */
2050 		reg_write(ohci, OHCI1394_BusOptions,
2051 			  be32_to_cpu(ohci->config_rom[2]));
2052 		ohci->config_rom[0] = ohci->next_header;
2053 		reg_write(ohci, OHCI1394_ConfigROMhdr,
2054 			  be32_to_cpu(ohci->next_header));
2055 	}
2056 
2057 	if (param_remote_dma) {
2058 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
2059 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
2060 	}
2061 
2062 	spin_unlock_irq(&ohci->lock);
2063 
2064 	if (free_rom)
2065 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2066 				  free_rom, free_rom_bus);
2067 
2068 	log_selfids(ohci, generation, self_id_count);
2069 
2070 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
2071 				 self_id_count, ohci->self_id_buffer,
2072 				 ohci->csr_state_setclear_abdicate);
2073 	ohci->csr_state_setclear_abdicate = false;
2074 }
2075 
2076 static irqreturn_t irq_handler(int irq, void *data)
2077 {
2078 	struct fw_ohci *ohci = data;
2079 	u32 event, iso_event;
2080 	int i;
2081 
2082 	event = reg_read(ohci, OHCI1394_IntEventClear);
2083 
2084 	if (!event || !~event)
2085 		return IRQ_NONE;
2086 
2087 	/*
2088 	 * busReset and postedWriteErr must not be cleared yet
2089 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
2090 	 */
2091 	reg_write(ohci, OHCI1394_IntEventClear,
2092 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
2093 	log_irqs(ohci, event);
2094 
2095 	if (event & OHCI1394_selfIDComplete)
2096 		queue_work(selfid_workqueue, &ohci->bus_reset_work);
2097 
2098 	if (event & OHCI1394_RQPkt)
2099 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
2100 
2101 	if (event & OHCI1394_RSPkt)
2102 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
2103 
2104 	if (event & OHCI1394_reqTxComplete)
2105 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
2106 
2107 	if (event & OHCI1394_respTxComplete)
2108 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
2109 
2110 	if (event & OHCI1394_isochRx) {
2111 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
2112 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
2113 
2114 		while (iso_event) {
2115 			i = ffs(iso_event) - 1;
2116 			tasklet_schedule(
2117 				&ohci->ir_context_list[i].context.tasklet);
2118 			iso_event &= ~(1 << i);
2119 		}
2120 	}
2121 
2122 	if (event & OHCI1394_isochTx) {
2123 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
2124 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
2125 
2126 		while (iso_event) {
2127 			i = ffs(iso_event) - 1;
2128 			tasklet_schedule(
2129 				&ohci->it_context_list[i].context.tasklet);
2130 			iso_event &= ~(1 << i);
2131 		}
2132 	}
2133 
2134 	if (unlikely(event & OHCI1394_regAccessFail))
2135 		ohci_err(ohci, "register access failure\n");
2136 
2137 	if (unlikely(event & OHCI1394_postedWriteErr)) {
2138 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
2139 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
2140 		reg_write(ohci, OHCI1394_IntEventClear,
2141 			  OHCI1394_postedWriteErr);
2142 		if (printk_ratelimit())
2143 			ohci_err(ohci, "PCI posted write error\n");
2144 	}
2145 
2146 	if (unlikely(event & OHCI1394_cycleTooLong)) {
2147 		if (printk_ratelimit())
2148 			ohci_notice(ohci, "isochronous cycle too long\n");
2149 		reg_write(ohci, OHCI1394_LinkControlSet,
2150 			  OHCI1394_LinkControl_cycleMaster);
2151 	}
2152 
2153 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
2154 		/*
2155 		 * We need to clear this event bit in order to make
2156 		 * cycleMatch isochronous I/O work.  In theory we should
2157 		 * stop active cycleMatch iso contexts now and restart
2158 		 * them at least two cycles later.  (FIXME?)
2159 		 */
2160 		if (printk_ratelimit())
2161 			ohci_notice(ohci, "isochronous cycle inconsistent\n");
2162 	}
2163 
2164 	if (unlikely(event & OHCI1394_unrecoverableError))
2165 		handle_dead_contexts(ohci);
2166 
2167 	if (event & OHCI1394_cycle64Seconds) {
2168 		spin_lock(&ohci->lock);
2169 		update_bus_time(ohci);
2170 		spin_unlock(&ohci->lock);
2171 	} else
2172 		flush_writes(ohci);
2173 
2174 	return IRQ_HANDLED;
2175 }
2176 
2177 static int software_reset(struct fw_ohci *ohci)
2178 {
2179 	u32 val;
2180 	int i;
2181 
2182 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
2183 	for (i = 0; i < 500; i++) {
2184 		val = reg_read(ohci, OHCI1394_HCControlSet);
2185 		if (!~val)
2186 			return -ENODEV; /* Card was ejected. */
2187 
2188 		if (!(val & OHCI1394_HCControl_softReset))
2189 			return 0;
2190 
2191 		msleep(1);
2192 	}
2193 
2194 	return -EBUSY;
2195 }
2196 
2197 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
2198 {
2199 	size_t size = length * 4;
2200 
2201 	memcpy(dest, src, size);
2202 	if (size < CONFIG_ROM_SIZE)
2203 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
2204 }
2205 
2206 static int configure_1394a_enhancements(struct fw_ohci *ohci)
2207 {
2208 	bool enable_1394a;
2209 	int ret, clear, set, offset;
2210 
2211 	/* Check if the driver should configure link and PHY. */
2212 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
2213 	      OHCI1394_HCControl_programPhyEnable))
2214 		return 0;
2215 
2216 	/* Paranoia: check whether the PHY supports 1394a, too. */
2217 	enable_1394a = false;
2218 	ret = read_phy_reg(ohci, 2);
2219 	if (ret < 0)
2220 		return ret;
2221 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
2222 		ret = read_paged_phy_reg(ohci, 1, 8);
2223 		if (ret < 0)
2224 			return ret;
2225 		if (ret >= 1)
2226 			enable_1394a = true;
2227 	}
2228 
2229 	if (ohci->quirks & QUIRK_NO_1394A)
2230 		enable_1394a = false;
2231 
2232 	/* Configure PHY and link consistently. */
2233 	if (enable_1394a) {
2234 		clear = 0;
2235 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2236 	} else {
2237 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2238 		set = 0;
2239 	}
2240 	ret = update_phy_reg(ohci, 5, clear, set);
2241 	if (ret < 0)
2242 		return ret;
2243 
2244 	if (enable_1394a)
2245 		offset = OHCI1394_HCControlSet;
2246 	else
2247 		offset = OHCI1394_HCControlClear;
2248 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2249 
2250 	/* Clean up: configuration has been taken care of. */
2251 	reg_write(ohci, OHCI1394_HCControlClear,
2252 		  OHCI1394_HCControl_programPhyEnable);
2253 
2254 	return 0;
2255 }
2256 
2257 static int probe_tsb41ba3d(struct fw_ohci *ohci)
2258 {
2259 	/* TI vendor ID = 0x080028, TSB41BA3D product ID = 0x833005 (sic) */
2260 	static const u8 id[] = { 0x08, 0x00, 0x28, 0x83, 0x30, 0x05, };
2261 	int reg, i;
2262 
2263 	reg = read_phy_reg(ohci, 2);
2264 	if (reg < 0)
2265 		return reg;
2266 	if ((reg & PHY_EXTENDED_REGISTERS) != PHY_EXTENDED_REGISTERS)
2267 		return 0;
2268 
2269 	for (i = ARRAY_SIZE(id) - 1; i >= 0; i--) {
2270 		reg = read_paged_phy_reg(ohci, 1, i + 10);
2271 		if (reg < 0)
2272 			return reg;
2273 		if (reg != id[i])
2274 			return 0;
2275 	}
2276 	return 1;
2277 }
2278 
2279 static int ohci_enable(struct fw_card *card,
2280 		       const __be32 *config_rom, size_t length)
2281 {
2282 	struct fw_ohci *ohci = fw_ohci(card);
2283 	u32 lps, version, irqs;
2284 	int i, ret;
2285 
2286 	if (software_reset(ohci)) {
2287 		ohci_err(ohci, "failed to reset ohci card\n");
2288 		return -EBUSY;
2289 	}
2290 
2291 	/*
2292 	 * Now enable LPS, which we need in order to start accessing
2293 	 * most of the registers.  In fact, on some cards (ALI M5251),
2294 	 * accessing registers in the SClk domain without LPS enabled
2295 	 * will lock up the machine.  Wait 50msec to make sure we have
2296 	 * full link enabled.  However, with some cards (well, at least
2297 	 * a JMicron PCIe card), we have to try again sometimes.
2298 	 *
2299 	 * TI TSB82AA2 + TSB81BA3(A) cards signal LPS enabled early but
2300 	 * cannot actually use the phy at that time.  These need tens of
2301 	 * millisecods pause between LPS write and first phy access too.
2302 	 *
2303 	 * But do not wait for 50msec on Agere/LSI cards.  Their phy
2304 	 * arbitration state machine may time out during such a long wait.
2305 	 */
2306 
2307 	reg_write(ohci, OHCI1394_HCControlSet,
2308 		  OHCI1394_HCControl_LPS |
2309 		  OHCI1394_HCControl_postedWriteEnable);
2310 	flush_writes(ohci);
2311 
2312 	if (!(ohci->quirks & QUIRK_PHY_LCTRL_TIMEOUT))
2313 		msleep(50);
2314 
2315 	for (lps = 0, i = 0; !lps && i < 150; i++) {
2316 		msleep(1);
2317 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2318 		      OHCI1394_HCControl_LPS;
2319 	}
2320 
2321 	if (!lps) {
2322 		ohci_err(ohci, "failed to set Link Power Status\n");
2323 		return -EIO;
2324 	}
2325 
2326 	if (ohci->quirks & QUIRK_TI_SLLZ059) {
2327 		ret = probe_tsb41ba3d(ohci);
2328 		if (ret < 0)
2329 			return ret;
2330 		if (ret)
2331 			ohci_notice(ohci, "local TSB41BA3D phy\n");
2332 		else
2333 			ohci->quirks &= ~QUIRK_TI_SLLZ059;
2334 	}
2335 
2336 	reg_write(ohci, OHCI1394_HCControlClear,
2337 		  OHCI1394_HCControl_noByteSwapData);
2338 
2339 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2340 	reg_write(ohci, OHCI1394_LinkControlSet,
2341 		  OHCI1394_LinkControl_cycleTimerEnable |
2342 		  OHCI1394_LinkControl_cycleMaster);
2343 
2344 	reg_write(ohci, OHCI1394_ATRetries,
2345 		  OHCI1394_MAX_AT_REQ_RETRIES |
2346 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2347 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2348 		  (200 << 16));
2349 
2350 	ohci->bus_time_running = false;
2351 
2352 	for (i = 0; i < 32; i++)
2353 		if (ohci->ir_context_support & (1 << i))
2354 			reg_write(ohci, OHCI1394_IsoRcvContextControlClear(i),
2355 				  IR_CONTEXT_MULTI_CHANNEL_MODE);
2356 
2357 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2358 	if (version >= OHCI_VERSION_1_1) {
2359 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2360 			  0xfffffffe);
2361 		card->broadcast_channel_auto_allocated = true;
2362 	}
2363 
2364 	/* Get implemented bits of the priority arbitration request counter. */
2365 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2366 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2367 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2368 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2369 
2370 	reg_write(ohci, OHCI1394_PhyUpperBound, FW_MAX_PHYSICAL_RANGE >> 16);
2371 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2372 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2373 
2374 	ret = configure_1394a_enhancements(ohci);
2375 	if (ret < 0)
2376 		return ret;
2377 
2378 	/* Activate link_on bit and contender bit in our self ID packets.*/
2379 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2380 	if (ret < 0)
2381 		return ret;
2382 
2383 	/*
2384 	 * When the link is not yet enabled, the atomic config rom
2385 	 * update mechanism described below in ohci_set_config_rom()
2386 	 * is not active.  We have to update ConfigRomHeader and
2387 	 * BusOptions manually, and the write to ConfigROMmap takes
2388 	 * effect immediately.  We tie this to the enabling of the
2389 	 * link, so we have a valid config rom before enabling - the
2390 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2391 	 * values before enabling.
2392 	 *
2393 	 * However, when the ConfigROMmap is written, some controllers
2394 	 * always read back quadlets 0 and 2 from the config rom to
2395 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2396 	 * They shouldn't do that in this initial case where the link
2397 	 * isn't enabled.  This means we have to use the same
2398 	 * workaround here, setting the bus header to 0 and then write
2399 	 * the right values in the bus reset tasklet.
2400 	 */
2401 
2402 	if (config_rom) {
2403 		ohci->next_config_rom =
2404 			dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2405 					   &ohci->next_config_rom_bus,
2406 					   GFP_KERNEL);
2407 		if (ohci->next_config_rom == NULL)
2408 			return -ENOMEM;
2409 
2410 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2411 	} else {
2412 		/*
2413 		 * In the suspend case, config_rom is NULL, which
2414 		 * means that we just reuse the old config rom.
2415 		 */
2416 		ohci->next_config_rom = ohci->config_rom;
2417 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2418 	}
2419 
2420 	ohci->next_header = ohci->next_config_rom[0];
2421 	ohci->next_config_rom[0] = 0;
2422 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2423 	reg_write(ohci, OHCI1394_BusOptions,
2424 		  be32_to_cpu(ohci->next_config_rom[2]));
2425 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2426 
2427 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2428 
2429 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2430 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2431 		OHCI1394_isochTx | OHCI1394_isochRx |
2432 		OHCI1394_postedWriteErr |
2433 		OHCI1394_selfIDComplete |
2434 		OHCI1394_regAccessFail |
2435 		OHCI1394_cycleInconsistent |
2436 		OHCI1394_unrecoverableError |
2437 		OHCI1394_cycleTooLong |
2438 		OHCI1394_masterIntEnable;
2439 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2440 		irqs |= OHCI1394_busReset;
2441 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2442 
2443 	reg_write(ohci, OHCI1394_HCControlSet,
2444 		  OHCI1394_HCControl_linkEnable |
2445 		  OHCI1394_HCControl_BIBimageValid);
2446 
2447 	reg_write(ohci, OHCI1394_LinkControlSet,
2448 		  OHCI1394_LinkControl_rcvSelfID |
2449 		  OHCI1394_LinkControl_rcvPhyPkt);
2450 
2451 	ar_context_run(&ohci->ar_request_ctx);
2452 	ar_context_run(&ohci->ar_response_ctx);
2453 
2454 	flush_writes(ohci);
2455 
2456 	/* We are ready to go, reset bus to finish initialization. */
2457 	fw_schedule_bus_reset(&ohci->card, false, true);
2458 
2459 	return 0;
2460 }
2461 
2462 static int ohci_set_config_rom(struct fw_card *card,
2463 			       const __be32 *config_rom, size_t length)
2464 {
2465 	struct fw_ohci *ohci;
2466 	__be32 *next_config_rom;
2467 	dma_addr_t uninitialized_var(next_config_rom_bus);
2468 
2469 	ohci = fw_ohci(card);
2470 
2471 	/*
2472 	 * When the OHCI controller is enabled, the config rom update
2473 	 * mechanism is a bit tricky, but easy enough to use.  See
2474 	 * section 5.5.6 in the OHCI specification.
2475 	 *
2476 	 * The OHCI controller caches the new config rom address in a
2477 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2478 	 * for the changes to take place.  When the bus reset is
2479 	 * detected, the controller loads the new values for the
2480 	 * ConfigRomHeader and BusOptions registers from the specified
2481 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2482 	 * shadow register. All automatically and atomically.
2483 	 *
2484 	 * Now, there's a twist to this story.  The automatic load of
2485 	 * ConfigRomHeader and BusOptions doesn't honor the
2486 	 * noByteSwapData bit, so with a be32 config rom, the
2487 	 * controller will load be32 values in to these registers
2488 	 * during the atomic update, even on litte endian
2489 	 * architectures.  The workaround we use is to put a 0 in the
2490 	 * header quadlet; 0 is endian agnostic and means that the
2491 	 * config rom isn't ready yet.  In the bus reset tasklet we
2492 	 * then set up the real values for the two registers.
2493 	 *
2494 	 * We use ohci->lock to avoid racing with the code that sets
2495 	 * ohci->next_config_rom to NULL (see bus_reset_work).
2496 	 */
2497 
2498 	next_config_rom =
2499 		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2500 				   &next_config_rom_bus, GFP_KERNEL);
2501 	if (next_config_rom == NULL)
2502 		return -ENOMEM;
2503 
2504 	spin_lock_irq(&ohci->lock);
2505 
2506 	/*
2507 	 * If there is not an already pending config_rom update,
2508 	 * push our new allocation into the ohci->next_config_rom
2509 	 * and then mark the local variable as null so that we
2510 	 * won't deallocate the new buffer.
2511 	 *
2512 	 * OTOH, if there is a pending config_rom update, just
2513 	 * use that buffer with the new config_rom data, and
2514 	 * let this routine free the unused DMA allocation.
2515 	 */
2516 
2517 	if (ohci->next_config_rom == NULL) {
2518 		ohci->next_config_rom = next_config_rom;
2519 		ohci->next_config_rom_bus = next_config_rom_bus;
2520 		next_config_rom = NULL;
2521 	}
2522 
2523 	copy_config_rom(ohci->next_config_rom, config_rom, length);
2524 
2525 	ohci->next_header = config_rom[0];
2526 	ohci->next_config_rom[0] = 0;
2527 
2528 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2529 
2530 	spin_unlock_irq(&ohci->lock);
2531 
2532 	/* If we didn't use the DMA allocation, delete it. */
2533 	if (next_config_rom != NULL)
2534 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2535 				  next_config_rom, next_config_rom_bus);
2536 
2537 	/*
2538 	 * Now initiate a bus reset to have the changes take
2539 	 * effect. We clean up the old config rom memory and DMA
2540 	 * mappings in the bus reset tasklet, since the OHCI
2541 	 * controller could need to access it before the bus reset
2542 	 * takes effect.
2543 	 */
2544 
2545 	fw_schedule_bus_reset(&ohci->card, true, true);
2546 
2547 	return 0;
2548 }
2549 
2550 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2551 {
2552 	struct fw_ohci *ohci = fw_ohci(card);
2553 
2554 	at_context_transmit(&ohci->at_request_ctx, packet);
2555 }
2556 
2557 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2558 {
2559 	struct fw_ohci *ohci = fw_ohci(card);
2560 
2561 	at_context_transmit(&ohci->at_response_ctx, packet);
2562 }
2563 
2564 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2565 {
2566 	struct fw_ohci *ohci = fw_ohci(card);
2567 	struct context *ctx = &ohci->at_request_ctx;
2568 	struct driver_data *driver_data = packet->driver_data;
2569 	int ret = -ENOENT;
2570 
2571 	tasklet_disable(&ctx->tasklet);
2572 
2573 	if (packet->ack != 0)
2574 		goto out;
2575 
2576 	if (packet->payload_mapped)
2577 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2578 				 packet->payload_length, DMA_TO_DEVICE);
2579 
2580 	log_ar_at_event(ohci, 'T', packet->speed, packet->header, 0x20);
2581 	driver_data->packet = NULL;
2582 	packet->ack = RCODE_CANCELLED;
2583 	packet->callback(packet, &ohci->card, packet->ack);
2584 	ret = 0;
2585  out:
2586 	tasklet_enable(&ctx->tasklet);
2587 
2588 	return ret;
2589 }
2590 
2591 static int ohci_enable_phys_dma(struct fw_card *card,
2592 				int node_id, int generation)
2593 {
2594 	struct fw_ohci *ohci = fw_ohci(card);
2595 	unsigned long flags;
2596 	int n, ret = 0;
2597 
2598 	if (param_remote_dma)
2599 		return 0;
2600 
2601 	/*
2602 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2603 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2604 	 */
2605 
2606 	spin_lock_irqsave(&ohci->lock, flags);
2607 
2608 	if (ohci->generation != generation) {
2609 		ret = -ESTALE;
2610 		goto out;
2611 	}
2612 
2613 	/*
2614 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2615 	 * enabled for _all_ nodes on remote buses.
2616 	 */
2617 
2618 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2619 	if (n < 32)
2620 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2621 	else
2622 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2623 
2624 	flush_writes(ohci);
2625  out:
2626 	spin_unlock_irqrestore(&ohci->lock, flags);
2627 
2628 	return ret;
2629 }
2630 
2631 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2632 {
2633 	struct fw_ohci *ohci = fw_ohci(card);
2634 	unsigned long flags;
2635 	u32 value;
2636 
2637 	switch (csr_offset) {
2638 	case CSR_STATE_CLEAR:
2639 	case CSR_STATE_SET:
2640 		if (ohci->is_root &&
2641 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2642 		     OHCI1394_LinkControl_cycleMaster))
2643 			value = CSR_STATE_BIT_CMSTR;
2644 		else
2645 			value = 0;
2646 		if (ohci->csr_state_setclear_abdicate)
2647 			value |= CSR_STATE_BIT_ABDICATE;
2648 
2649 		return value;
2650 
2651 	case CSR_NODE_IDS:
2652 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2653 
2654 	case CSR_CYCLE_TIME:
2655 		return get_cycle_time(ohci);
2656 
2657 	case CSR_BUS_TIME:
2658 		/*
2659 		 * We might be called just after the cycle timer has wrapped
2660 		 * around but just before the cycle64Seconds handler, so we
2661 		 * better check here, too, if the bus time needs to be updated.
2662 		 */
2663 		spin_lock_irqsave(&ohci->lock, flags);
2664 		value = update_bus_time(ohci);
2665 		spin_unlock_irqrestore(&ohci->lock, flags);
2666 		return value;
2667 
2668 	case CSR_BUSY_TIMEOUT:
2669 		value = reg_read(ohci, OHCI1394_ATRetries);
2670 		return (value >> 4) & 0x0ffff00f;
2671 
2672 	case CSR_PRIORITY_BUDGET:
2673 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2674 			(ohci->pri_req_max << 8);
2675 
2676 	default:
2677 		WARN_ON(1);
2678 		return 0;
2679 	}
2680 }
2681 
2682 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2683 {
2684 	struct fw_ohci *ohci = fw_ohci(card);
2685 	unsigned long flags;
2686 
2687 	switch (csr_offset) {
2688 	case CSR_STATE_CLEAR:
2689 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2690 			reg_write(ohci, OHCI1394_LinkControlClear,
2691 				  OHCI1394_LinkControl_cycleMaster);
2692 			flush_writes(ohci);
2693 		}
2694 		if (value & CSR_STATE_BIT_ABDICATE)
2695 			ohci->csr_state_setclear_abdicate = false;
2696 		break;
2697 
2698 	case CSR_STATE_SET:
2699 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2700 			reg_write(ohci, OHCI1394_LinkControlSet,
2701 				  OHCI1394_LinkControl_cycleMaster);
2702 			flush_writes(ohci);
2703 		}
2704 		if (value & CSR_STATE_BIT_ABDICATE)
2705 			ohci->csr_state_setclear_abdicate = true;
2706 		break;
2707 
2708 	case CSR_NODE_IDS:
2709 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2710 		flush_writes(ohci);
2711 		break;
2712 
2713 	case CSR_CYCLE_TIME:
2714 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2715 		reg_write(ohci, OHCI1394_IntEventSet,
2716 			  OHCI1394_cycleInconsistent);
2717 		flush_writes(ohci);
2718 		break;
2719 
2720 	case CSR_BUS_TIME:
2721 		spin_lock_irqsave(&ohci->lock, flags);
2722 		ohci->bus_time = (update_bus_time(ohci) & 0x40) |
2723 		                 (value & ~0x7f);
2724 		spin_unlock_irqrestore(&ohci->lock, flags);
2725 		break;
2726 
2727 	case CSR_BUSY_TIMEOUT:
2728 		value = (value & 0xf) | ((value & 0xf) << 4) |
2729 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2730 		reg_write(ohci, OHCI1394_ATRetries, value);
2731 		flush_writes(ohci);
2732 		break;
2733 
2734 	case CSR_PRIORITY_BUDGET:
2735 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2736 		flush_writes(ohci);
2737 		break;
2738 
2739 	default:
2740 		WARN_ON(1);
2741 		break;
2742 	}
2743 }
2744 
2745 static void flush_iso_completions(struct iso_context *ctx)
2746 {
2747 	ctx->base.callback.sc(&ctx->base, ctx->last_timestamp,
2748 			      ctx->header_length, ctx->header,
2749 			      ctx->base.callback_data);
2750 	ctx->header_length = 0;
2751 }
2752 
2753 static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr)
2754 {
2755 	u32 *ctx_hdr;
2756 
2757 	if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
2758 		if (ctx->base.drop_overflow_headers)
2759 			return;
2760 		flush_iso_completions(ctx);
2761 	}
2762 
2763 	ctx_hdr = ctx->header + ctx->header_length;
2764 	ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
2765 
2766 	/*
2767 	 * The two iso header quadlets are byteswapped to little
2768 	 * endian by the controller, but we want to present them
2769 	 * as big endian for consistency with the bus endianness.
2770 	 */
2771 	if (ctx->base.header_size > 0)
2772 		ctx_hdr[0] = swab32(dma_hdr[1]); /* iso packet header */
2773 	if (ctx->base.header_size > 4)
2774 		ctx_hdr[1] = swab32(dma_hdr[0]); /* timestamp */
2775 	if (ctx->base.header_size > 8)
2776 		memcpy(&ctx_hdr[2], &dma_hdr[2], ctx->base.header_size - 8);
2777 	ctx->header_length += ctx->base.header_size;
2778 }
2779 
2780 static int handle_ir_packet_per_buffer(struct context *context,
2781 				       struct descriptor *d,
2782 				       struct descriptor *last)
2783 {
2784 	struct iso_context *ctx =
2785 		container_of(context, struct iso_context, context);
2786 	struct descriptor *pd;
2787 	u32 buffer_dma;
2788 
2789 	for (pd = d; pd <= last; pd++)
2790 		if (pd->transfer_status)
2791 			break;
2792 	if (pd > last)
2793 		/* Descriptor(s) not done yet, stop iteration */
2794 		return 0;
2795 
2796 	while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
2797 		d++;
2798 		buffer_dma = le32_to_cpu(d->data_address);
2799 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2800 					      buffer_dma & PAGE_MASK,
2801 					      buffer_dma & ~PAGE_MASK,
2802 					      le16_to_cpu(d->req_count),
2803 					      DMA_FROM_DEVICE);
2804 	}
2805 
2806 	copy_iso_headers(ctx, (u32 *) (last + 1));
2807 
2808 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2809 		flush_iso_completions(ctx);
2810 
2811 	return 1;
2812 }
2813 
2814 /* d == last because each descriptor block is only a single descriptor. */
2815 static int handle_ir_buffer_fill(struct context *context,
2816 				 struct descriptor *d,
2817 				 struct descriptor *last)
2818 {
2819 	struct iso_context *ctx =
2820 		container_of(context, struct iso_context, context);
2821 	unsigned int req_count, res_count, completed;
2822 	u32 buffer_dma;
2823 
2824 	req_count = le16_to_cpu(last->req_count);
2825 	res_count = le16_to_cpu(ACCESS_ONCE(last->res_count));
2826 	completed = req_count - res_count;
2827 	buffer_dma = le32_to_cpu(last->data_address);
2828 
2829 	if (completed > 0) {
2830 		ctx->mc_buffer_bus = buffer_dma;
2831 		ctx->mc_completed = completed;
2832 	}
2833 
2834 	if (res_count != 0)
2835 		/* Descriptor(s) not done yet, stop iteration */
2836 		return 0;
2837 
2838 	dma_sync_single_range_for_cpu(context->ohci->card.device,
2839 				      buffer_dma & PAGE_MASK,
2840 				      buffer_dma & ~PAGE_MASK,
2841 				      completed, DMA_FROM_DEVICE);
2842 
2843 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) {
2844 		ctx->base.callback.mc(&ctx->base,
2845 				      buffer_dma + completed,
2846 				      ctx->base.callback_data);
2847 		ctx->mc_completed = 0;
2848 	}
2849 
2850 	return 1;
2851 }
2852 
2853 static void flush_ir_buffer_fill(struct iso_context *ctx)
2854 {
2855 	dma_sync_single_range_for_cpu(ctx->context.ohci->card.device,
2856 				      ctx->mc_buffer_bus & PAGE_MASK,
2857 				      ctx->mc_buffer_bus & ~PAGE_MASK,
2858 				      ctx->mc_completed, DMA_FROM_DEVICE);
2859 
2860 	ctx->base.callback.mc(&ctx->base,
2861 			      ctx->mc_buffer_bus + ctx->mc_completed,
2862 			      ctx->base.callback_data);
2863 	ctx->mc_completed = 0;
2864 }
2865 
2866 static inline void sync_it_packet_for_cpu(struct context *context,
2867 					  struct descriptor *pd)
2868 {
2869 	__le16 control;
2870 	u32 buffer_dma;
2871 
2872 	/* only packets beginning with OUTPUT_MORE* have data buffers */
2873 	if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2874 		return;
2875 
2876 	/* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
2877 	pd += 2;
2878 
2879 	/*
2880 	 * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
2881 	 * data buffer is in the context program's coherent page and must not
2882 	 * be synced.
2883 	 */
2884 	if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
2885 	    (context->current_bus          & PAGE_MASK)) {
2886 		if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
2887 			return;
2888 		pd++;
2889 	}
2890 
2891 	do {
2892 		buffer_dma = le32_to_cpu(pd->data_address);
2893 		dma_sync_single_range_for_cpu(context->ohci->card.device,
2894 					      buffer_dma & PAGE_MASK,
2895 					      buffer_dma & ~PAGE_MASK,
2896 					      le16_to_cpu(pd->req_count),
2897 					      DMA_TO_DEVICE);
2898 		control = pd->control;
2899 		pd++;
2900 	} while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
2901 }
2902 
2903 static int handle_it_packet(struct context *context,
2904 			    struct descriptor *d,
2905 			    struct descriptor *last)
2906 {
2907 	struct iso_context *ctx =
2908 		container_of(context, struct iso_context, context);
2909 	struct descriptor *pd;
2910 	__be32 *ctx_hdr;
2911 
2912 	for (pd = d; pd <= last; pd++)
2913 		if (pd->transfer_status)
2914 			break;
2915 	if (pd > last)
2916 		/* Descriptor(s) not done yet, stop iteration */
2917 		return 0;
2918 
2919 	sync_it_packet_for_cpu(context, d);
2920 
2921 	if (ctx->header_length + 4 > PAGE_SIZE) {
2922 		if (ctx->base.drop_overflow_headers)
2923 			return 1;
2924 		flush_iso_completions(ctx);
2925 	}
2926 
2927 	ctx_hdr = ctx->header + ctx->header_length;
2928 	ctx->last_timestamp = le16_to_cpu(last->res_count);
2929 	/* Present this value as big-endian to match the receive code */
2930 	*ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) |
2931 			       le16_to_cpu(pd->res_count));
2932 	ctx->header_length += 4;
2933 
2934 	if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS))
2935 		flush_iso_completions(ctx);
2936 
2937 	return 1;
2938 }
2939 
2940 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2941 {
2942 	u32 hi = channels >> 32, lo = channels;
2943 
2944 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2945 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2946 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2947 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2948 	mmiowb();
2949 	ohci->mc_channels = channels;
2950 }
2951 
2952 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2953 				int type, int channel, size_t header_size)
2954 {
2955 	struct fw_ohci *ohci = fw_ohci(card);
2956 	struct iso_context *uninitialized_var(ctx);
2957 	descriptor_callback_t uninitialized_var(callback);
2958 	u64 *uninitialized_var(channels);
2959 	u32 *uninitialized_var(mask), uninitialized_var(regs);
2960 	int index, ret = -EBUSY;
2961 
2962 	spin_lock_irq(&ohci->lock);
2963 
2964 	switch (type) {
2965 	case FW_ISO_CONTEXT_TRANSMIT:
2966 		mask     = &ohci->it_context_mask;
2967 		callback = handle_it_packet;
2968 		index    = ffs(*mask) - 1;
2969 		if (index >= 0) {
2970 			*mask &= ~(1 << index);
2971 			regs = OHCI1394_IsoXmitContextBase(index);
2972 			ctx  = &ohci->it_context_list[index];
2973 		}
2974 		break;
2975 
2976 	case FW_ISO_CONTEXT_RECEIVE:
2977 		channels = &ohci->ir_context_channels;
2978 		mask     = &ohci->ir_context_mask;
2979 		callback = handle_ir_packet_per_buffer;
2980 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2981 		if (index >= 0) {
2982 			*channels &= ~(1ULL << channel);
2983 			*mask     &= ~(1 << index);
2984 			regs = OHCI1394_IsoRcvContextBase(index);
2985 			ctx  = &ohci->ir_context_list[index];
2986 		}
2987 		break;
2988 
2989 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2990 		mask     = &ohci->ir_context_mask;
2991 		callback = handle_ir_buffer_fill;
2992 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2993 		if (index >= 0) {
2994 			ohci->mc_allocated = true;
2995 			*mask &= ~(1 << index);
2996 			regs = OHCI1394_IsoRcvContextBase(index);
2997 			ctx  = &ohci->ir_context_list[index];
2998 		}
2999 		break;
3000 
3001 	default:
3002 		index = -1;
3003 		ret = -ENOSYS;
3004 	}
3005 
3006 	spin_unlock_irq(&ohci->lock);
3007 
3008 	if (index < 0)
3009 		return ERR_PTR(ret);
3010 
3011 	memset(ctx, 0, sizeof(*ctx));
3012 	ctx->header_length = 0;
3013 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
3014 	if (ctx->header == NULL) {
3015 		ret = -ENOMEM;
3016 		goto out;
3017 	}
3018 	ret = context_init(&ctx->context, ohci, regs, callback);
3019 	if (ret < 0)
3020 		goto out_with_header;
3021 
3022 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
3023 		set_multichannel_mask(ohci, 0);
3024 		ctx->mc_completed = 0;
3025 	}
3026 
3027 	return &ctx->base;
3028 
3029  out_with_header:
3030 	free_page((unsigned long)ctx->header);
3031  out:
3032 	spin_lock_irq(&ohci->lock);
3033 
3034 	switch (type) {
3035 	case FW_ISO_CONTEXT_RECEIVE:
3036 		*channels |= 1ULL << channel;
3037 		break;
3038 
3039 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3040 		ohci->mc_allocated = false;
3041 		break;
3042 	}
3043 	*mask |= 1 << index;
3044 
3045 	spin_unlock_irq(&ohci->lock);
3046 
3047 	return ERR_PTR(ret);
3048 }
3049 
3050 static int ohci_start_iso(struct fw_iso_context *base,
3051 			  s32 cycle, u32 sync, u32 tags)
3052 {
3053 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3054 	struct fw_ohci *ohci = ctx->context.ohci;
3055 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
3056 	int index;
3057 
3058 	/* the controller cannot start without any queued packets */
3059 	if (ctx->context.last->branch_address == 0)
3060 		return -ENODATA;
3061 
3062 	switch (ctx->base.type) {
3063 	case FW_ISO_CONTEXT_TRANSMIT:
3064 		index = ctx - ohci->it_context_list;
3065 		match = 0;
3066 		if (cycle >= 0)
3067 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
3068 				(cycle & 0x7fff) << 16;
3069 
3070 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
3071 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
3072 		context_run(&ctx->context, match);
3073 		break;
3074 
3075 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3076 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
3077 		/* fall through */
3078 	case FW_ISO_CONTEXT_RECEIVE:
3079 		index = ctx - ohci->ir_context_list;
3080 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
3081 		if (cycle >= 0) {
3082 			match |= (cycle & 0x07fff) << 12;
3083 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
3084 		}
3085 
3086 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
3087 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
3088 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
3089 		context_run(&ctx->context, control);
3090 
3091 		ctx->sync = sync;
3092 		ctx->tags = tags;
3093 
3094 		break;
3095 	}
3096 
3097 	return 0;
3098 }
3099 
3100 static int ohci_stop_iso(struct fw_iso_context *base)
3101 {
3102 	struct fw_ohci *ohci = fw_ohci(base->card);
3103 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3104 	int index;
3105 
3106 	switch (ctx->base.type) {
3107 	case FW_ISO_CONTEXT_TRANSMIT:
3108 		index = ctx - ohci->it_context_list;
3109 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
3110 		break;
3111 
3112 	case FW_ISO_CONTEXT_RECEIVE:
3113 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3114 		index = ctx - ohci->ir_context_list;
3115 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
3116 		break;
3117 	}
3118 	flush_writes(ohci);
3119 	context_stop(&ctx->context);
3120 	tasklet_kill(&ctx->context.tasklet);
3121 
3122 	return 0;
3123 }
3124 
3125 static void ohci_free_iso_context(struct fw_iso_context *base)
3126 {
3127 	struct fw_ohci *ohci = fw_ohci(base->card);
3128 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3129 	unsigned long flags;
3130 	int index;
3131 
3132 	ohci_stop_iso(base);
3133 	context_release(&ctx->context);
3134 	free_page((unsigned long)ctx->header);
3135 
3136 	spin_lock_irqsave(&ohci->lock, flags);
3137 
3138 	switch (base->type) {
3139 	case FW_ISO_CONTEXT_TRANSMIT:
3140 		index = ctx - ohci->it_context_list;
3141 		ohci->it_context_mask |= 1 << index;
3142 		break;
3143 
3144 	case FW_ISO_CONTEXT_RECEIVE:
3145 		index = ctx - ohci->ir_context_list;
3146 		ohci->ir_context_mask |= 1 << index;
3147 		ohci->ir_context_channels |= 1ULL << base->channel;
3148 		break;
3149 
3150 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3151 		index = ctx - ohci->ir_context_list;
3152 		ohci->ir_context_mask |= 1 << index;
3153 		ohci->ir_context_channels |= ohci->mc_channels;
3154 		ohci->mc_channels = 0;
3155 		ohci->mc_allocated = false;
3156 		break;
3157 	}
3158 
3159 	spin_unlock_irqrestore(&ohci->lock, flags);
3160 }
3161 
3162 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
3163 {
3164 	struct fw_ohci *ohci = fw_ohci(base->card);
3165 	unsigned long flags;
3166 	int ret;
3167 
3168 	switch (base->type) {
3169 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3170 
3171 		spin_lock_irqsave(&ohci->lock, flags);
3172 
3173 		/* Don't allow multichannel to grab other contexts' channels. */
3174 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
3175 			*channels = ohci->ir_context_channels;
3176 			ret = -EBUSY;
3177 		} else {
3178 			set_multichannel_mask(ohci, *channels);
3179 			ret = 0;
3180 		}
3181 
3182 		spin_unlock_irqrestore(&ohci->lock, flags);
3183 
3184 		break;
3185 	default:
3186 		ret = -EINVAL;
3187 	}
3188 
3189 	return ret;
3190 }
3191 
3192 #ifdef CONFIG_PM
3193 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
3194 {
3195 	int i;
3196 	struct iso_context *ctx;
3197 
3198 	for (i = 0 ; i < ohci->n_ir ; i++) {
3199 		ctx = &ohci->ir_context_list[i];
3200 		if (ctx->context.running)
3201 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3202 	}
3203 
3204 	for (i = 0 ; i < ohci->n_it ; i++) {
3205 		ctx = &ohci->it_context_list[i];
3206 		if (ctx->context.running)
3207 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
3208 	}
3209 }
3210 #endif
3211 
3212 static int queue_iso_transmit(struct iso_context *ctx,
3213 			      struct fw_iso_packet *packet,
3214 			      struct fw_iso_buffer *buffer,
3215 			      unsigned long payload)
3216 {
3217 	struct descriptor *d, *last, *pd;
3218 	struct fw_iso_packet *p;
3219 	__le32 *header;
3220 	dma_addr_t d_bus, page_bus;
3221 	u32 z, header_z, payload_z, irq;
3222 	u32 payload_index, payload_end_index, next_page_index;
3223 	int page, end_page, i, length, offset;
3224 
3225 	p = packet;
3226 	payload_index = payload;
3227 
3228 	if (p->skip)
3229 		z = 1;
3230 	else
3231 		z = 2;
3232 	if (p->header_length > 0)
3233 		z++;
3234 
3235 	/* Determine the first page the payload isn't contained in. */
3236 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
3237 	if (p->payload_length > 0)
3238 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
3239 	else
3240 		payload_z = 0;
3241 
3242 	z += payload_z;
3243 
3244 	/* Get header size in number of descriptors. */
3245 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
3246 
3247 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
3248 	if (d == NULL)
3249 		return -ENOMEM;
3250 
3251 	if (!p->skip) {
3252 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
3253 		d[0].req_count = cpu_to_le16(8);
3254 		/*
3255 		 * Link the skip address to this descriptor itself.  This causes
3256 		 * a context to skip a cycle whenever lost cycles or FIFO
3257 		 * overruns occur, without dropping the data.  The application
3258 		 * should then decide whether this is an error condition or not.
3259 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
3260 		 */
3261 		d[0].branch_address = cpu_to_le32(d_bus | z);
3262 
3263 		header = (__le32 *) &d[1];
3264 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
3265 					IT_HEADER_TAG(p->tag) |
3266 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
3267 					IT_HEADER_CHANNEL(ctx->base.channel) |
3268 					IT_HEADER_SPEED(ctx->base.speed));
3269 		header[1] =
3270 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
3271 							  p->payload_length));
3272 	}
3273 
3274 	if (p->header_length > 0) {
3275 		d[2].req_count    = cpu_to_le16(p->header_length);
3276 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
3277 		memcpy(&d[z], p->header, p->header_length);
3278 	}
3279 
3280 	pd = d + z - payload_z;
3281 	payload_end_index = payload_index + p->payload_length;
3282 	for (i = 0; i < payload_z; i++) {
3283 		page               = payload_index >> PAGE_SHIFT;
3284 		offset             = payload_index & ~PAGE_MASK;
3285 		next_page_index    = (page + 1) << PAGE_SHIFT;
3286 		length             =
3287 			min(next_page_index, payload_end_index) - payload_index;
3288 		pd[i].req_count    = cpu_to_le16(length);
3289 
3290 		page_bus = page_private(buffer->pages[page]);
3291 		pd[i].data_address = cpu_to_le32(page_bus + offset);
3292 
3293 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3294 						 page_bus, offset, length,
3295 						 DMA_TO_DEVICE);
3296 
3297 		payload_index += length;
3298 	}
3299 
3300 	if (p->interrupt)
3301 		irq = DESCRIPTOR_IRQ_ALWAYS;
3302 	else
3303 		irq = DESCRIPTOR_NO_IRQ;
3304 
3305 	last = z == 2 ? d : d + z - 1;
3306 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
3307 				     DESCRIPTOR_STATUS |
3308 				     DESCRIPTOR_BRANCH_ALWAYS |
3309 				     irq);
3310 
3311 	context_append(&ctx->context, d, z, header_z);
3312 
3313 	return 0;
3314 }
3315 
3316 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
3317 				       struct fw_iso_packet *packet,
3318 				       struct fw_iso_buffer *buffer,
3319 				       unsigned long payload)
3320 {
3321 	struct device *device = ctx->context.ohci->card.device;
3322 	struct descriptor *d, *pd;
3323 	dma_addr_t d_bus, page_bus;
3324 	u32 z, header_z, rest;
3325 	int i, j, length;
3326 	int page, offset, packet_count, header_size, payload_per_buffer;
3327 
3328 	/*
3329 	 * The OHCI controller puts the isochronous header and trailer in the
3330 	 * buffer, so we need at least 8 bytes.
3331 	 */
3332 	packet_count = packet->header_length / ctx->base.header_size;
3333 	header_size  = max(ctx->base.header_size, (size_t)8);
3334 
3335 	/* Get header size in number of descriptors. */
3336 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
3337 	page     = payload >> PAGE_SHIFT;
3338 	offset   = payload & ~PAGE_MASK;
3339 	payload_per_buffer = packet->payload_length / packet_count;
3340 
3341 	for (i = 0; i < packet_count; i++) {
3342 		/* d points to the header descriptor */
3343 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
3344 		d = context_get_descriptors(&ctx->context,
3345 				z + header_z, &d_bus);
3346 		if (d == NULL)
3347 			return -ENOMEM;
3348 
3349 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
3350 					      DESCRIPTOR_INPUT_MORE);
3351 		if (packet->skip && i == 0)
3352 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3353 		d->req_count    = cpu_to_le16(header_size);
3354 		d->res_count    = d->req_count;
3355 		d->transfer_status = 0;
3356 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
3357 
3358 		rest = payload_per_buffer;
3359 		pd = d;
3360 		for (j = 1; j < z; j++) {
3361 			pd++;
3362 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3363 						  DESCRIPTOR_INPUT_MORE);
3364 
3365 			if (offset + rest < PAGE_SIZE)
3366 				length = rest;
3367 			else
3368 				length = PAGE_SIZE - offset;
3369 			pd->req_count = cpu_to_le16(length);
3370 			pd->res_count = pd->req_count;
3371 			pd->transfer_status = 0;
3372 
3373 			page_bus = page_private(buffer->pages[page]);
3374 			pd->data_address = cpu_to_le32(page_bus + offset);
3375 
3376 			dma_sync_single_range_for_device(device, page_bus,
3377 							 offset, length,
3378 							 DMA_FROM_DEVICE);
3379 
3380 			offset = (offset + length) & ~PAGE_MASK;
3381 			rest -= length;
3382 			if (offset == 0)
3383 				page++;
3384 		}
3385 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3386 					  DESCRIPTOR_INPUT_LAST |
3387 					  DESCRIPTOR_BRANCH_ALWAYS);
3388 		if (packet->interrupt && i == packet_count - 1)
3389 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3390 
3391 		context_append(&ctx->context, d, z, header_z);
3392 	}
3393 
3394 	return 0;
3395 }
3396 
3397 static int queue_iso_buffer_fill(struct iso_context *ctx,
3398 				 struct fw_iso_packet *packet,
3399 				 struct fw_iso_buffer *buffer,
3400 				 unsigned long payload)
3401 {
3402 	struct descriptor *d;
3403 	dma_addr_t d_bus, page_bus;
3404 	int page, offset, rest, z, i, length;
3405 
3406 	page   = payload >> PAGE_SHIFT;
3407 	offset = payload & ~PAGE_MASK;
3408 	rest   = packet->payload_length;
3409 
3410 	/* We need one descriptor for each page in the buffer. */
3411 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3412 
3413 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3414 		return -EFAULT;
3415 
3416 	for (i = 0; i < z; i++) {
3417 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3418 		if (d == NULL)
3419 			return -ENOMEM;
3420 
3421 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3422 					 DESCRIPTOR_BRANCH_ALWAYS);
3423 		if (packet->skip && i == 0)
3424 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3425 		if (packet->interrupt && i == z - 1)
3426 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3427 
3428 		if (offset + rest < PAGE_SIZE)
3429 			length = rest;
3430 		else
3431 			length = PAGE_SIZE - offset;
3432 		d->req_count = cpu_to_le16(length);
3433 		d->res_count = d->req_count;
3434 		d->transfer_status = 0;
3435 
3436 		page_bus = page_private(buffer->pages[page]);
3437 		d->data_address = cpu_to_le32(page_bus + offset);
3438 
3439 		dma_sync_single_range_for_device(ctx->context.ohci->card.device,
3440 						 page_bus, offset, length,
3441 						 DMA_FROM_DEVICE);
3442 
3443 		rest -= length;
3444 		offset = 0;
3445 		page++;
3446 
3447 		context_append(&ctx->context, d, 1, 0);
3448 	}
3449 
3450 	return 0;
3451 }
3452 
3453 static int ohci_queue_iso(struct fw_iso_context *base,
3454 			  struct fw_iso_packet *packet,
3455 			  struct fw_iso_buffer *buffer,
3456 			  unsigned long payload)
3457 {
3458 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3459 	unsigned long flags;
3460 	int ret = -ENOSYS;
3461 
3462 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3463 	switch (base->type) {
3464 	case FW_ISO_CONTEXT_TRANSMIT:
3465 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3466 		break;
3467 	case FW_ISO_CONTEXT_RECEIVE:
3468 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3469 		break;
3470 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3471 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3472 		break;
3473 	}
3474 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3475 
3476 	return ret;
3477 }
3478 
3479 static void ohci_flush_queue_iso(struct fw_iso_context *base)
3480 {
3481 	struct context *ctx =
3482 			&container_of(base, struct iso_context, base)->context;
3483 
3484 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
3485 }
3486 
3487 static int ohci_flush_iso_completions(struct fw_iso_context *base)
3488 {
3489 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3490 	int ret = 0;
3491 
3492 	tasklet_disable(&ctx->context.tasklet);
3493 
3494 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
3495 		context_tasklet((unsigned long)&ctx->context);
3496 
3497 		switch (base->type) {
3498 		case FW_ISO_CONTEXT_TRANSMIT:
3499 		case FW_ISO_CONTEXT_RECEIVE:
3500 			if (ctx->header_length != 0)
3501 				flush_iso_completions(ctx);
3502 			break;
3503 		case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3504 			if (ctx->mc_completed != 0)
3505 				flush_ir_buffer_fill(ctx);
3506 			break;
3507 		default:
3508 			ret = -ENOSYS;
3509 		}
3510 
3511 		clear_bit_unlock(0, &ctx->flushing_completions);
3512 		smp_mb__after_clear_bit();
3513 	}
3514 
3515 	tasklet_enable(&ctx->context.tasklet);
3516 
3517 	return ret;
3518 }
3519 
3520 static const struct fw_card_driver ohci_driver = {
3521 	.enable			= ohci_enable,
3522 	.read_phy_reg		= ohci_read_phy_reg,
3523 	.update_phy_reg		= ohci_update_phy_reg,
3524 	.set_config_rom		= ohci_set_config_rom,
3525 	.send_request		= ohci_send_request,
3526 	.send_response		= ohci_send_response,
3527 	.cancel_packet		= ohci_cancel_packet,
3528 	.enable_phys_dma	= ohci_enable_phys_dma,
3529 	.read_csr		= ohci_read_csr,
3530 	.write_csr		= ohci_write_csr,
3531 
3532 	.allocate_iso_context	= ohci_allocate_iso_context,
3533 	.free_iso_context	= ohci_free_iso_context,
3534 	.set_iso_channels	= ohci_set_iso_channels,
3535 	.queue_iso		= ohci_queue_iso,
3536 	.flush_queue_iso	= ohci_flush_queue_iso,
3537 	.flush_iso_completions	= ohci_flush_iso_completions,
3538 	.start_iso		= ohci_start_iso,
3539 	.stop_iso		= ohci_stop_iso,
3540 };
3541 
3542 #ifdef CONFIG_PPC_PMAC
3543 static void pmac_ohci_on(struct pci_dev *dev)
3544 {
3545 	if (machine_is(powermac)) {
3546 		struct device_node *ofn = pci_device_to_OF_node(dev);
3547 
3548 		if (ofn) {
3549 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3550 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3551 		}
3552 	}
3553 }
3554 
3555 static void pmac_ohci_off(struct pci_dev *dev)
3556 {
3557 	if (machine_is(powermac)) {
3558 		struct device_node *ofn = pci_device_to_OF_node(dev);
3559 
3560 		if (ofn) {
3561 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3562 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3563 		}
3564 	}
3565 }
3566 #else
3567 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3568 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3569 #endif /* CONFIG_PPC_PMAC */
3570 
3571 static int pci_probe(struct pci_dev *dev,
3572 			       const struct pci_device_id *ent)
3573 {
3574 	struct fw_ohci *ohci;
3575 	u32 bus_options, max_receive, link_speed, version;
3576 	u64 guid;
3577 	int i, err;
3578 	size_t size;
3579 
3580 	if (dev->vendor == PCI_VENDOR_ID_PINNACLE_SYSTEMS) {
3581 		dev_err(&dev->dev, "Pinnacle MovieBoard is not yet supported\n");
3582 		return -ENOSYS;
3583 	}
3584 
3585 	ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3586 	if (ohci == NULL) {
3587 		err = -ENOMEM;
3588 		goto fail;
3589 	}
3590 
3591 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3592 
3593 	pmac_ohci_on(dev);
3594 
3595 	err = pci_enable_device(dev);
3596 	if (err) {
3597 		dev_err(&dev->dev, "failed to enable OHCI hardware\n");
3598 		goto fail_free;
3599 	}
3600 
3601 	pci_set_master(dev);
3602 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3603 	pci_set_drvdata(dev, ohci);
3604 
3605 	spin_lock_init(&ohci->lock);
3606 	mutex_init(&ohci->phy_reg_mutex);
3607 
3608 	INIT_WORK(&ohci->bus_reset_work, bus_reset_work);
3609 
3610 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_MEM) ||
3611 	    pci_resource_len(dev, 0) < OHCI1394_REGISTER_SIZE) {
3612 		ohci_err(ohci, "invalid MMIO resource\n");
3613 		err = -ENXIO;
3614 		goto fail_disable;
3615 	}
3616 
3617 	err = pci_request_region(dev, 0, ohci_driver_name);
3618 	if (err) {
3619 		ohci_err(ohci, "MMIO resource unavailable\n");
3620 		goto fail_disable;
3621 	}
3622 
3623 	ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3624 	if (ohci->registers == NULL) {
3625 		ohci_err(ohci, "failed to remap registers\n");
3626 		err = -ENXIO;
3627 		goto fail_iomem;
3628 	}
3629 
3630 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3631 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3632 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3633 		     ohci_quirks[i].device == dev->device) &&
3634 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3635 		     ohci_quirks[i].revision >= dev->revision)) {
3636 			ohci->quirks = ohci_quirks[i].flags;
3637 			break;
3638 		}
3639 	if (param_quirks)
3640 		ohci->quirks = param_quirks;
3641 
3642 	/*
3643 	 * Because dma_alloc_coherent() allocates at least one page,
3644 	 * we save space by using a common buffer for the AR request/
3645 	 * response descriptors and the self IDs buffer.
3646 	 */
3647 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3648 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3649 	ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3650 					       PAGE_SIZE,
3651 					       &ohci->misc_buffer_bus,
3652 					       GFP_KERNEL);
3653 	if (!ohci->misc_buffer) {
3654 		err = -ENOMEM;
3655 		goto fail_iounmap;
3656 	}
3657 
3658 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3659 			      OHCI1394_AsReqRcvContextControlSet);
3660 	if (err < 0)
3661 		goto fail_misc_buf;
3662 
3663 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3664 			      OHCI1394_AsRspRcvContextControlSet);
3665 	if (err < 0)
3666 		goto fail_arreq_ctx;
3667 
3668 	err = context_init(&ohci->at_request_ctx, ohci,
3669 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3670 	if (err < 0)
3671 		goto fail_arrsp_ctx;
3672 
3673 	err = context_init(&ohci->at_response_ctx, ohci,
3674 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3675 	if (err < 0)
3676 		goto fail_atreq_ctx;
3677 
3678 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3679 	ohci->ir_context_channels = ~0ULL;
3680 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3681 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3682 	ohci->ir_context_mask = ohci->ir_context_support;
3683 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3684 	size = sizeof(struct iso_context) * ohci->n_ir;
3685 	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3686 
3687 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3688 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3689 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3690 	ohci->it_context_mask = ohci->it_context_support;
3691 	ohci->n_it = hweight32(ohci->it_context_mask);
3692 	size = sizeof(struct iso_context) * ohci->n_it;
3693 	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3694 
3695 	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3696 		err = -ENOMEM;
3697 		goto fail_contexts;
3698 	}
3699 
3700 	ohci->self_id     = ohci->misc_buffer     + PAGE_SIZE/2;
3701 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3702 
3703 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3704 	max_receive = (bus_options >> 12) & 0xf;
3705 	link_speed = bus_options & 0x7;
3706 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3707 		reg_read(ohci, OHCI1394_GUIDLo);
3708 
3709 	if (!(ohci->quirks & QUIRK_NO_MSI))
3710 		pci_enable_msi(dev);
3711 	if (request_irq(dev->irq, irq_handler,
3712 			pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
3713 			ohci_driver_name, ohci)) {
3714 		ohci_err(ohci, "failed to allocate interrupt %d\n", dev->irq);
3715 		err = -EIO;
3716 		goto fail_msi;
3717 	}
3718 
3719 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3720 	if (err)
3721 		goto fail_irq;
3722 
3723 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3724 	ohci_notice(ohci,
3725 		    "added OHCI v%x.%x device as card %d, "
3726 		    "%d IR + %d IT contexts, quirks 0x%x%s\n",
3727 		    version >> 16, version & 0xff, ohci->card.index,
3728 		    ohci->n_ir, ohci->n_it, ohci->quirks,
3729 		    reg_read(ohci, OHCI1394_PhyUpperBound) ?
3730 			", >4 GB phys DMA" : "");
3731 
3732 	return 0;
3733 
3734  fail_irq:
3735 	free_irq(dev->irq, ohci);
3736  fail_msi:
3737 	pci_disable_msi(dev);
3738  fail_contexts:
3739 	kfree(ohci->ir_context_list);
3740 	kfree(ohci->it_context_list);
3741 	context_release(&ohci->at_response_ctx);
3742  fail_atreq_ctx:
3743 	context_release(&ohci->at_request_ctx);
3744  fail_arrsp_ctx:
3745 	ar_context_release(&ohci->ar_response_ctx);
3746  fail_arreq_ctx:
3747 	ar_context_release(&ohci->ar_request_ctx);
3748  fail_misc_buf:
3749 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3750 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3751  fail_iounmap:
3752 	pci_iounmap(dev, ohci->registers);
3753  fail_iomem:
3754 	pci_release_region(dev, 0);
3755  fail_disable:
3756 	pci_disable_device(dev);
3757  fail_free:
3758 	kfree(ohci);
3759 	pmac_ohci_off(dev);
3760  fail:
3761 	return err;
3762 }
3763 
3764 static void pci_remove(struct pci_dev *dev)
3765 {
3766 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3767 
3768 	/*
3769 	 * If the removal is happening from the suspend state, LPS won't be
3770 	 * enabled and host registers (eg., IntMaskClear) won't be accessible.
3771 	 */
3772 	if (reg_read(ohci, OHCI1394_HCControlSet) & OHCI1394_HCControl_LPS) {
3773 		reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3774 		flush_writes(ohci);
3775 	}
3776 	cancel_work_sync(&ohci->bus_reset_work);
3777 	fw_core_remove_card(&ohci->card);
3778 
3779 	/*
3780 	 * FIXME: Fail all pending packets here, now that the upper
3781 	 * layers can't queue any more.
3782 	 */
3783 
3784 	software_reset(ohci);
3785 	free_irq(dev->irq, ohci);
3786 
3787 	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3788 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3789 				  ohci->next_config_rom, ohci->next_config_rom_bus);
3790 	if (ohci->config_rom)
3791 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3792 				  ohci->config_rom, ohci->config_rom_bus);
3793 	ar_context_release(&ohci->ar_request_ctx);
3794 	ar_context_release(&ohci->ar_response_ctx);
3795 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3796 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3797 	context_release(&ohci->at_request_ctx);
3798 	context_release(&ohci->at_response_ctx);
3799 	kfree(ohci->it_context_list);
3800 	kfree(ohci->ir_context_list);
3801 	pci_disable_msi(dev);
3802 	pci_iounmap(dev, ohci->registers);
3803 	pci_release_region(dev, 0);
3804 	pci_disable_device(dev);
3805 	kfree(ohci);
3806 	pmac_ohci_off(dev);
3807 
3808 	dev_notice(&dev->dev, "removed fw-ohci device\n");
3809 }
3810 
3811 #ifdef CONFIG_PM
3812 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3813 {
3814 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3815 	int err;
3816 
3817 	software_reset(ohci);
3818 	err = pci_save_state(dev);
3819 	if (err) {
3820 		ohci_err(ohci, "pci_save_state failed\n");
3821 		return err;
3822 	}
3823 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3824 	if (err)
3825 		ohci_err(ohci, "pci_set_power_state failed with %d\n", err);
3826 	pmac_ohci_off(dev);
3827 
3828 	return 0;
3829 }
3830 
3831 static int pci_resume(struct pci_dev *dev)
3832 {
3833 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3834 	int err;
3835 
3836 	pmac_ohci_on(dev);
3837 	pci_set_power_state(dev, PCI_D0);
3838 	pci_restore_state(dev);
3839 	err = pci_enable_device(dev);
3840 	if (err) {
3841 		ohci_err(ohci, "pci_enable_device failed\n");
3842 		return err;
3843 	}
3844 
3845 	/* Some systems don't setup GUID register on resume from ram  */
3846 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3847 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3848 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3849 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3850 	}
3851 
3852 	err = ohci_enable(&ohci->card, NULL, 0);
3853 	if (err)
3854 		return err;
3855 
3856 	ohci_resume_iso_dma(ohci);
3857 
3858 	return 0;
3859 }
3860 #endif
3861 
3862 static const struct pci_device_id pci_table[] = {
3863 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3864 	{ }
3865 };
3866 
3867 MODULE_DEVICE_TABLE(pci, pci_table);
3868 
3869 static struct pci_driver fw_ohci_pci_driver = {
3870 	.name		= ohci_driver_name,
3871 	.id_table	= pci_table,
3872 	.probe		= pci_probe,
3873 	.remove		= pci_remove,
3874 #ifdef CONFIG_PM
3875 	.resume		= pci_resume,
3876 	.suspend	= pci_suspend,
3877 #endif
3878 };
3879 
3880 static int __init fw_ohci_init(void)
3881 {
3882 	selfid_workqueue = alloc_workqueue(KBUILD_MODNAME, WQ_MEM_RECLAIM, 0);
3883 	if (!selfid_workqueue)
3884 		return -ENOMEM;
3885 
3886 	return pci_register_driver(&fw_ohci_pci_driver);
3887 }
3888 
3889 static void __exit fw_ohci_cleanup(void)
3890 {
3891 	pci_unregister_driver(&fw_ohci_pci_driver);
3892 	destroy_workqueue(selfid_workqueue);
3893 }
3894 
3895 module_init(fw_ohci_init);
3896 module_exit(fw_ohci_cleanup);
3897 
3898 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3899 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3900 MODULE_LICENSE("GPL");
3901 
3902 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3903 MODULE_ALIAS("ohci1394");
3904