xref: /openbmc/linux/drivers/firewire/ohci.c (revision 6a108a14)
1 /*
2  * Driver for OHCI 1394 controllers
3  *
4  * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 #include <linux/bitops.h>
22 #include <linux/bug.h>
23 #include <linux/compiler.h>
24 #include <linux/delay.h>
25 #include <linux/device.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/firewire.h>
28 #include <linux/firewire-constants.h>
29 #include <linux/init.h>
30 #include <linux/interrupt.h>
31 #include <linux/io.h>
32 #include <linux/kernel.h>
33 #include <linux/list.h>
34 #include <linux/mm.h>
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/mutex.h>
38 #include <linux/pci.h>
39 #include <linux/pci_ids.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/string.h>
43 #include <linux/time.h>
44 #include <linux/vmalloc.h>
45 
46 #include <asm/byteorder.h>
47 #include <asm/page.h>
48 #include <asm/system.h>
49 
50 #ifdef CONFIG_PPC_PMAC
51 #include <asm/pmac_feature.h>
52 #endif
53 
54 #include "core.h"
55 #include "ohci.h"
56 
57 #define DESCRIPTOR_OUTPUT_MORE		0
58 #define DESCRIPTOR_OUTPUT_LAST		(1 << 12)
59 #define DESCRIPTOR_INPUT_MORE		(2 << 12)
60 #define DESCRIPTOR_INPUT_LAST		(3 << 12)
61 #define DESCRIPTOR_STATUS		(1 << 11)
62 #define DESCRIPTOR_KEY_IMMEDIATE	(2 << 8)
63 #define DESCRIPTOR_PING			(1 << 7)
64 #define DESCRIPTOR_YY			(1 << 6)
65 #define DESCRIPTOR_NO_IRQ		(0 << 4)
66 #define DESCRIPTOR_IRQ_ERROR		(1 << 4)
67 #define DESCRIPTOR_IRQ_ALWAYS		(3 << 4)
68 #define DESCRIPTOR_BRANCH_ALWAYS	(3 << 2)
69 #define DESCRIPTOR_WAIT			(3 << 0)
70 
71 struct descriptor {
72 	__le16 req_count;
73 	__le16 control;
74 	__le32 data_address;
75 	__le32 branch_address;
76 	__le16 res_count;
77 	__le16 transfer_status;
78 } __attribute__((aligned(16)));
79 
80 #define CONTROL_SET(regs)	(regs)
81 #define CONTROL_CLEAR(regs)	((regs) + 4)
82 #define COMMAND_PTR(regs)	((regs) + 12)
83 #define CONTEXT_MATCH(regs)	((regs) + 16)
84 
85 #define AR_BUFFER_SIZE	(32*1024)
86 #define AR_BUFFERS_MIN	DIV_ROUND_UP(AR_BUFFER_SIZE, PAGE_SIZE)
87 /* we need at least two pages for proper list management */
88 #define AR_BUFFERS	(AR_BUFFERS_MIN >= 2 ? AR_BUFFERS_MIN : 2)
89 
90 #define MAX_ASYNC_PAYLOAD	4096
91 #define MAX_AR_PACKET_SIZE	(16 + MAX_ASYNC_PAYLOAD + 4)
92 #define AR_WRAPAROUND_PAGES	DIV_ROUND_UP(MAX_AR_PACKET_SIZE, PAGE_SIZE)
93 
94 struct ar_context {
95 	struct fw_ohci *ohci;
96 	struct page *pages[AR_BUFFERS];
97 	void *buffer;
98 	struct descriptor *descriptors;
99 	dma_addr_t descriptors_bus;
100 	void *pointer;
101 	unsigned int last_buffer_index;
102 	u32 regs;
103 	struct tasklet_struct tasklet;
104 };
105 
106 struct context;
107 
108 typedef int (*descriptor_callback_t)(struct context *ctx,
109 				     struct descriptor *d,
110 				     struct descriptor *last);
111 
112 /*
113  * A buffer that contains a block of DMA-able coherent memory used for
114  * storing a portion of a DMA descriptor program.
115  */
116 struct descriptor_buffer {
117 	struct list_head list;
118 	dma_addr_t buffer_bus;
119 	size_t buffer_size;
120 	size_t used;
121 	struct descriptor buffer[0];
122 };
123 
124 struct context {
125 	struct fw_ohci *ohci;
126 	u32 regs;
127 	int total_allocation;
128 	bool running;
129 	bool flushing;
130 
131 	/*
132 	 * List of page-sized buffers for storing DMA descriptors.
133 	 * Head of list contains buffers in use and tail of list contains
134 	 * free buffers.
135 	 */
136 	struct list_head buffer_list;
137 
138 	/*
139 	 * Pointer to a buffer inside buffer_list that contains the tail
140 	 * end of the current DMA program.
141 	 */
142 	struct descriptor_buffer *buffer_tail;
143 
144 	/*
145 	 * The descriptor containing the branch address of the first
146 	 * descriptor that has not yet been filled by the device.
147 	 */
148 	struct descriptor *last;
149 
150 	/*
151 	 * The last descriptor in the DMA program.  It contains the branch
152 	 * address that must be updated upon appending a new descriptor.
153 	 */
154 	struct descriptor *prev;
155 
156 	descriptor_callback_t callback;
157 
158 	struct tasklet_struct tasklet;
159 };
160 
161 #define IT_HEADER_SY(v)          ((v) <<  0)
162 #define IT_HEADER_TCODE(v)       ((v) <<  4)
163 #define IT_HEADER_CHANNEL(v)     ((v) <<  8)
164 #define IT_HEADER_TAG(v)         ((v) << 14)
165 #define IT_HEADER_SPEED(v)       ((v) << 16)
166 #define IT_HEADER_DATA_LENGTH(v) ((v) << 16)
167 
168 struct iso_context {
169 	struct fw_iso_context base;
170 	struct context context;
171 	int excess_bytes;
172 	void *header;
173 	size_t header_length;
174 
175 	u8 sync;
176 	u8 tags;
177 };
178 
179 #define CONFIG_ROM_SIZE 1024
180 
181 struct fw_ohci {
182 	struct fw_card card;
183 
184 	__iomem char *registers;
185 	int node_id;
186 	int generation;
187 	int request_generation;	/* for timestamping incoming requests */
188 	unsigned quirks;
189 	unsigned int pri_req_max;
190 	u32 bus_time;
191 	bool is_root;
192 	bool csr_state_setclear_abdicate;
193 	int n_ir;
194 	int n_it;
195 	/*
196 	 * Spinlock for accessing fw_ohci data.  Never call out of
197 	 * this driver with this lock held.
198 	 */
199 	spinlock_t lock;
200 
201 	struct mutex phy_reg_mutex;
202 
203 	void *misc_buffer;
204 	dma_addr_t misc_buffer_bus;
205 
206 	struct ar_context ar_request_ctx;
207 	struct ar_context ar_response_ctx;
208 	struct context at_request_ctx;
209 	struct context at_response_ctx;
210 
211 	u32 it_context_mask;     /* unoccupied IT contexts */
212 	struct iso_context *it_context_list;
213 	u64 ir_context_channels; /* unoccupied channels */
214 	u32 ir_context_mask;     /* unoccupied IR contexts */
215 	struct iso_context *ir_context_list;
216 	u64 mc_channels; /* channels in use by the multichannel IR context */
217 	bool mc_allocated;
218 
219 	__be32    *config_rom;
220 	dma_addr_t config_rom_bus;
221 	__be32    *next_config_rom;
222 	dma_addr_t next_config_rom_bus;
223 	__be32     next_header;
224 
225 	__le32    *self_id_cpu;
226 	dma_addr_t self_id_bus;
227 	struct tasklet_struct bus_reset_tasklet;
228 
229 	u32 self_id_buffer[512];
230 };
231 
232 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
233 {
234 	return container_of(card, struct fw_ohci, card);
235 }
236 
237 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
238 #define IR_CONTEXT_BUFFER_FILL		0x80000000
239 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
240 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
241 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
242 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
243 
244 #define CONTEXT_RUN	0x8000
245 #define CONTEXT_WAKE	0x1000
246 #define CONTEXT_DEAD	0x0800
247 #define CONTEXT_ACTIVE	0x0400
248 
249 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
250 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
251 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
252 
253 #define OHCI1394_REGISTER_SIZE		0x800
254 #define OHCI_LOOP_COUNT			500
255 #define OHCI1394_PCI_HCI_Control	0x40
256 #define SELF_ID_BUF_SIZE		0x800
257 #define OHCI_TCODE_PHY_PACKET		0x0e
258 #define OHCI_VERSION_1_1		0x010010
259 
260 static char ohci_driver_name[] = KBUILD_MODNAME;
261 
262 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
263 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
264 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
265 
266 #define QUIRK_CYCLE_TIMER		1
267 #define QUIRK_RESET_PACKET		2
268 #define QUIRK_BE_HEADERS		4
269 #define QUIRK_NO_1394A			8
270 #define QUIRK_NO_MSI			16
271 
272 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
273 static const struct {
274 	unsigned short vendor, device, revision, flags;
275 } ohci_quirks[] = {
276 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
277 		QUIRK_CYCLE_TIMER},
278 
279 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
280 		QUIRK_BE_HEADERS},
281 
282 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
283 		QUIRK_NO_MSI},
284 
285 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
286 		QUIRK_NO_MSI},
287 
288 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
289 		QUIRK_CYCLE_TIMER},
290 
291 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
292 		QUIRK_CYCLE_TIMER},
293 
294 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
295 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
296 
297 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
298 		QUIRK_RESET_PACKET},
299 
300 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
301 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
302 };
303 
304 /* This overrides anything that was found in ohci_quirks[]. */
305 static int param_quirks;
306 module_param_named(quirks, param_quirks, int, 0644);
307 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
308 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
309 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
310 	", AR/selfID endianess = "	__stringify(QUIRK_BE_HEADERS)
311 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
312 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
313 	")");
314 
315 #define OHCI_PARAM_DEBUG_AT_AR		1
316 #define OHCI_PARAM_DEBUG_SELFIDS	2
317 #define OHCI_PARAM_DEBUG_IRQS		4
318 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
319 
320 #ifdef CONFIG_FIREWIRE_OHCI_DEBUG
321 
322 static int param_debug;
323 module_param_named(debug, param_debug, int, 0644);
324 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
325 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
326 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
327 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
328 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
329 	", or a combination, or all = -1)");
330 
331 static void log_irqs(u32 evt)
332 {
333 	if (likely(!(param_debug &
334 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
335 		return;
336 
337 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
338 	    !(evt & OHCI1394_busReset))
339 		return;
340 
341 	fw_notify("IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
342 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
343 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
344 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
345 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
346 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
347 	    evt & OHCI1394_isochRx		? " IR"			: "",
348 	    evt & OHCI1394_isochTx		? " IT"			: "",
349 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
350 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
351 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
352 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
353 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
354 	    evt & OHCI1394_busReset		? " busReset"		: "",
355 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
356 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
357 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
358 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
359 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
360 		    OHCI1394_cycleInconsistent |
361 		    OHCI1394_regAccessFail | OHCI1394_busReset)
362 						? " ?"			: "");
363 }
364 
365 static const char *speed[] = {
366 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
367 };
368 static const char *power[] = {
369 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
370 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
371 };
372 static const char port[] = { '.', '-', 'p', 'c', };
373 
374 static char _p(u32 *s, int shift)
375 {
376 	return port[*s >> shift & 3];
377 }
378 
379 static void log_selfids(int node_id, int generation, int self_id_count, u32 *s)
380 {
381 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
382 		return;
383 
384 	fw_notify("%d selfIDs, generation %d, local node ID %04x\n",
385 		  self_id_count, generation, node_id);
386 
387 	for (; self_id_count--; ++s)
388 		if ((*s & 1 << 23) == 0)
389 			fw_notify("selfID 0: %08x, phy %d [%c%c%c] "
390 			    "%s gc=%d %s %s%s%s\n",
391 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
392 			    speed[*s >> 14 & 3], *s >> 16 & 63,
393 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
394 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
395 		else
396 			fw_notify("selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
397 			    *s, *s >> 24 & 63,
398 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
399 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
400 }
401 
402 static const char *evts[] = {
403 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
404 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
405 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
406 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
407 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
408 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
409 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
410 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
411 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
412 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
413 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
414 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
415 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
416 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
417 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
418 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
419 	[0x20] = "pending/cancelled",
420 };
421 static const char *tcodes[] = {
422 	[0x0] = "QW req",		[0x1] = "BW req",
423 	[0x2] = "W resp",		[0x3] = "-reserved-",
424 	[0x4] = "QR req",		[0x5] = "BR req",
425 	[0x6] = "QR resp",		[0x7] = "BR resp",
426 	[0x8] = "cycle start",		[0x9] = "Lk req",
427 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
428 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
429 	[0xe] = "link internal",	[0xf] = "-reserved-",
430 };
431 
432 static void log_ar_at_event(char dir, int speed, u32 *header, int evt)
433 {
434 	int tcode = header[0] >> 4 & 0xf;
435 	char specific[12];
436 
437 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
438 		return;
439 
440 	if (unlikely(evt >= ARRAY_SIZE(evts)))
441 			evt = 0x1f;
442 
443 	if (evt == OHCI1394_evt_bus_reset) {
444 		fw_notify("A%c evt_bus_reset, generation %d\n",
445 		    dir, (header[2] >> 16) & 0xff);
446 		return;
447 	}
448 
449 	switch (tcode) {
450 	case 0x0: case 0x6: case 0x8:
451 		snprintf(specific, sizeof(specific), " = %08x",
452 			 be32_to_cpu((__force __be32)header[3]));
453 		break;
454 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
455 		snprintf(specific, sizeof(specific), " %x,%x",
456 			 header[3] >> 16, header[3] & 0xffff);
457 		break;
458 	default:
459 		specific[0] = '\0';
460 	}
461 
462 	switch (tcode) {
463 	case 0xa:
464 		fw_notify("A%c %s, %s\n", dir, evts[evt], tcodes[tcode]);
465 		break;
466 	case 0xe:
467 		fw_notify("A%c %s, PHY %08x %08x\n",
468 			  dir, evts[evt], header[1], header[2]);
469 		break;
470 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
471 		fw_notify("A%c spd %x tl %02x, "
472 		    "%04x -> %04x, %s, "
473 		    "%s, %04x%08x%s\n",
474 		    dir, speed, header[0] >> 10 & 0x3f,
475 		    header[1] >> 16, header[0] >> 16, evts[evt],
476 		    tcodes[tcode], header[1] & 0xffff, header[2], specific);
477 		break;
478 	default:
479 		fw_notify("A%c spd %x tl %02x, "
480 		    "%04x -> %04x, %s, "
481 		    "%s%s\n",
482 		    dir, speed, header[0] >> 10 & 0x3f,
483 		    header[1] >> 16, header[0] >> 16, evts[evt],
484 		    tcodes[tcode], specific);
485 	}
486 }
487 
488 #else
489 
490 #define param_debug 0
491 static inline void log_irqs(u32 evt) {}
492 static inline void log_selfids(int node_id, int generation, int self_id_count, u32 *s) {}
493 static inline void log_ar_at_event(char dir, int speed, u32 *header, int evt) {}
494 
495 #endif /* CONFIG_FIREWIRE_OHCI_DEBUG */
496 
497 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
498 {
499 	writel(data, ohci->registers + offset);
500 }
501 
502 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
503 {
504 	return readl(ohci->registers + offset);
505 }
506 
507 static inline void flush_writes(const struct fw_ohci *ohci)
508 {
509 	/* Do a dummy read to flush writes. */
510 	reg_read(ohci, OHCI1394_Version);
511 }
512 
513 static int read_phy_reg(struct fw_ohci *ohci, int addr)
514 {
515 	u32 val;
516 	int i;
517 
518 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
519 	for (i = 0; i < 3 + 100; i++) {
520 		val = reg_read(ohci, OHCI1394_PhyControl);
521 		if (val & OHCI1394_PhyControl_ReadDone)
522 			return OHCI1394_PhyControl_ReadData(val);
523 
524 		/*
525 		 * Try a few times without waiting.  Sleeping is necessary
526 		 * only when the link/PHY interface is busy.
527 		 */
528 		if (i >= 3)
529 			msleep(1);
530 	}
531 	fw_error("failed to read phy reg\n");
532 
533 	return -EBUSY;
534 }
535 
536 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
537 {
538 	int i;
539 
540 	reg_write(ohci, OHCI1394_PhyControl,
541 		  OHCI1394_PhyControl_Write(addr, val));
542 	for (i = 0; i < 3 + 100; i++) {
543 		val = reg_read(ohci, OHCI1394_PhyControl);
544 		if (!(val & OHCI1394_PhyControl_WritePending))
545 			return 0;
546 
547 		if (i >= 3)
548 			msleep(1);
549 	}
550 	fw_error("failed to write phy reg\n");
551 
552 	return -EBUSY;
553 }
554 
555 static int update_phy_reg(struct fw_ohci *ohci, int addr,
556 			  int clear_bits, int set_bits)
557 {
558 	int ret = read_phy_reg(ohci, addr);
559 	if (ret < 0)
560 		return ret;
561 
562 	/*
563 	 * The interrupt status bits are cleared by writing a one bit.
564 	 * Avoid clearing them unless explicitly requested in set_bits.
565 	 */
566 	if (addr == 5)
567 		clear_bits |= PHY_INT_STATUS_BITS;
568 
569 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
570 }
571 
572 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
573 {
574 	int ret;
575 
576 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
577 	if (ret < 0)
578 		return ret;
579 
580 	return read_phy_reg(ohci, addr);
581 }
582 
583 static int ohci_read_phy_reg(struct fw_card *card, int addr)
584 {
585 	struct fw_ohci *ohci = fw_ohci(card);
586 	int ret;
587 
588 	mutex_lock(&ohci->phy_reg_mutex);
589 	ret = read_phy_reg(ohci, addr);
590 	mutex_unlock(&ohci->phy_reg_mutex);
591 
592 	return ret;
593 }
594 
595 static int ohci_update_phy_reg(struct fw_card *card, int addr,
596 			       int clear_bits, int set_bits)
597 {
598 	struct fw_ohci *ohci = fw_ohci(card);
599 	int ret;
600 
601 	mutex_lock(&ohci->phy_reg_mutex);
602 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
603 	mutex_unlock(&ohci->phy_reg_mutex);
604 
605 	return ret;
606 }
607 
608 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
609 {
610 	return page_private(ctx->pages[i]);
611 }
612 
613 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
614 {
615 	struct descriptor *d;
616 
617 	d = &ctx->descriptors[index];
618 	d->branch_address  &= cpu_to_le32(~0xf);
619 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
620 	d->transfer_status =  0;
621 
622 	wmb(); /* finish init of new descriptors before branch_address update */
623 	d = &ctx->descriptors[ctx->last_buffer_index];
624 	d->branch_address  |= cpu_to_le32(1);
625 
626 	ctx->last_buffer_index = index;
627 
628 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
629 	flush_writes(ctx->ohci);
630 }
631 
632 static void ar_context_release(struct ar_context *ctx)
633 {
634 	unsigned int i;
635 
636 	if (ctx->buffer)
637 		vm_unmap_ram(ctx->buffer, AR_BUFFERS + AR_WRAPAROUND_PAGES);
638 
639 	for (i = 0; i < AR_BUFFERS; i++)
640 		if (ctx->pages[i]) {
641 			dma_unmap_page(ctx->ohci->card.device,
642 				       ar_buffer_bus(ctx, i),
643 				       PAGE_SIZE, DMA_FROM_DEVICE);
644 			__free_page(ctx->pages[i]);
645 		}
646 }
647 
648 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
649 {
650 	if (reg_read(ctx->ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
651 		reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
652 		flush_writes(ctx->ohci);
653 
654 		fw_error("AR error: %s; DMA stopped\n", error_msg);
655 	}
656 	/* FIXME: restart? */
657 }
658 
659 static inline unsigned int ar_next_buffer_index(unsigned int index)
660 {
661 	return (index + 1) % AR_BUFFERS;
662 }
663 
664 static inline unsigned int ar_prev_buffer_index(unsigned int index)
665 {
666 	return (index - 1 + AR_BUFFERS) % AR_BUFFERS;
667 }
668 
669 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
670 {
671 	return ar_next_buffer_index(ctx->last_buffer_index);
672 }
673 
674 /*
675  * We search for the buffer that contains the last AR packet DMA data written
676  * by the controller.
677  */
678 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
679 						 unsigned int *buffer_offset)
680 {
681 	unsigned int i, next_i, last = ctx->last_buffer_index;
682 	__le16 res_count, next_res_count;
683 
684 	i = ar_first_buffer_index(ctx);
685 	res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
686 
687 	/* A buffer that is not yet completely filled must be the last one. */
688 	while (i != last && res_count == 0) {
689 
690 		/* Peek at the next descriptor. */
691 		next_i = ar_next_buffer_index(i);
692 		rmb(); /* read descriptors in order */
693 		next_res_count = ACCESS_ONCE(
694 				ctx->descriptors[next_i].res_count);
695 		/*
696 		 * If the next descriptor is still empty, we must stop at this
697 		 * descriptor.
698 		 */
699 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
700 			/*
701 			 * The exception is when the DMA data for one packet is
702 			 * split over three buffers; in this case, the middle
703 			 * buffer's descriptor might be never updated by the
704 			 * controller and look still empty, and we have to peek
705 			 * at the third one.
706 			 */
707 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
708 				next_i = ar_next_buffer_index(next_i);
709 				rmb();
710 				next_res_count = ACCESS_ONCE(
711 					ctx->descriptors[next_i].res_count);
712 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
713 					goto next_buffer_is_active;
714 			}
715 
716 			break;
717 		}
718 
719 next_buffer_is_active:
720 		i = next_i;
721 		res_count = next_res_count;
722 	}
723 
724 	rmb(); /* read res_count before the DMA data */
725 
726 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
727 	if (*buffer_offset > PAGE_SIZE) {
728 		*buffer_offset = 0;
729 		ar_context_abort(ctx, "corrupted descriptor");
730 	}
731 
732 	return i;
733 }
734 
735 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
736 				    unsigned int end_buffer_index,
737 				    unsigned int end_buffer_offset)
738 {
739 	unsigned int i;
740 
741 	i = ar_first_buffer_index(ctx);
742 	while (i != end_buffer_index) {
743 		dma_sync_single_for_cpu(ctx->ohci->card.device,
744 					ar_buffer_bus(ctx, i),
745 					PAGE_SIZE, DMA_FROM_DEVICE);
746 		i = ar_next_buffer_index(i);
747 	}
748 	if (end_buffer_offset > 0)
749 		dma_sync_single_for_cpu(ctx->ohci->card.device,
750 					ar_buffer_bus(ctx, i),
751 					end_buffer_offset, DMA_FROM_DEVICE);
752 }
753 
754 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
755 #define cond_le32_to_cpu(v) \
756 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
757 #else
758 #define cond_le32_to_cpu(v) le32_to_cpu(v)
759 #endif
760 
761 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
762 {
763 	struct fw_ohci *ohci = ctx->ohci;
764 	struct fw_packet p;
765 	u32 status, length, tcode;
766 	int evt;
767 
768 	p.header[0] = cond_le32_to_cpu(buffer[0]);
769 	p.header[1] = cond_le32_to_cpu(buffer[1]);
770 	p.header[2] = cond_le32_to_cpu(buffer[2]);
771 
772 	tcode = (p.header[0] >> 4) & 0x0f;
773 	switch (tcode) {
774 	case TCODE_WRITE_QUADLET_REQUEST:
775 	case TCODE_READ_QUADLET_RESPONSE:
776 		p.header[3] = (__force __u32) buffer[3];
777 		p.header_length = 16;
778 		p.payload_length = 0;
779 		break;
780 
781 	case TCODE_READ_BLOCK_REQUEST :
782 		p.header[3] = cond_le32_to_cpu(buffer[3]);
783 		p.header_length = 16;
784 		p.payload_length = 0;
785 		break;
786 
787 	case TCODE_WRITE_BLOCK_REQUEST:
788 	case TCODE_READ_BLOCK_RESPONSE:
789 	case TCODE_LOCK_REQUEST:
790 	case TCODE_LOCK_RESPONSE:
791 		p.header[3] = cond_le32_to_cpu(buffer[3]);
792 		p.header_length = 16;
793 		p.payload_length = p.header[3] >> 16;
794 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
795 			ar_context_abort(ctx, "invalid packet length");
796 			return NULL;
797 		}
798 		break;
799 
800 	case TCODE_WRITE_RESPONSE:
801 	case TCODE_READ_QUADLET_REQUEST:
802 	case OHCI_TCODE_PHY_PACKET:
803 		p.header_length = 12;
804 		p.payload_length = 0;
805 		break;
806 
807 	default:
808 		ar_context_abort(ctx, "invalid tcode");
809 		return NULL;
810 	}
811 
812 	p.payload = (void *) buffer + p.header_length;
813 
814 	/* FIXME: What to do about evt_* errors? */
815 	length = (p.header_length + p.payload_length + 3) / 4;
816 	status = cond_le32_to_cpu(buffer[length]);
817 	evt    = (status >> 16) & 0x1f;
818 
819 	p.ack        = evt - 16;
820 	p.speed      = (status >> 21) & 0x7;
821 	p.timestamp  = status & 0xffff;
822 	p.generation = ohci->request_generation;
823 
824 	log_ar_at_event('R', p.speed, p.header, evt);
825 
826 	/*
827 	 * Several controllers, notably from NEC and VIA, forget to
828 	 * write ack_complete status at PHY packet reception.
829 	 */
830 	if (evt == OHCI1394_evt_no_status &&
831 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
832 		p.ack = ACK_COMPLETE;
833 
834 	/*
835 	 * The OHCI bus reset handler synthesizes a PHY packet with
836 	 * the new generation number when a bus reset happens (see
837 	 * section 8.4.2.3).  This helps us determine when a request
838 	 * was received and make sure we send the response in the same
839 	 * generation.  We only need this for requests; for responses
840 	 * we use the unique tlabel for finding the matching
841 	 * request.
842 	 *
843 	 * Alas some chips sometimes emit bus reset packets with a
844 	 * wrong generation.  We set the correct generation for these
845 	 * at a slightly incorrect time (in bus_reset_tasklet).
846 	 */
847 	if (evt == OHCI1394_evt_bus_reset) {
848 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
849 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
850 	} else if (ctx == &ohci->ar_request_ctx) {
851 		fw_core_handle_request(&ohci->card, &p);
852 	} else {
853 		fw_core_handle_response(&ohci->card, &p);
854 	}
855 
856 	return buffer + length + 1;
857 }
858 
859 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
860 {
861 	void *next;
862 
863 	while (p < end) {
864 		next = handle_ar_packet(ctx, p);
865 		if (!next)
866 			return p;
867 		p = next;
868 	}
869 
870 	return p;
871 }
872 
873 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
874 {
875 	unsigned int i;
876 
877 	i = ar_first_buffer_index(ctx);
878 	while (i != end_buffer) {
879 		dma_sync_single_for_device(ctx->ohci->card.device,
880 					   ar_buffer_bus(ctx, i),
881 					   PAGE_SIZE, DMA_FROM_DEVICE);
882 		ar_context_link_page(ctx, i);
883 		i = ar_next_buffer_index(i);
884 	}
885 }
886 
887 static void ar_context_tasklet(unsigned long data)
888 {
889 	struct ar_context *ctx = (struct ar_context *)data;
890 	unsigned int end_buffer_index, end_buffer_offset;
891 	void *p, *end;
892 
893 	p = ctx->pointer;
894 	if (!p)
895 		return;
896 
897 	end_buffer_index = ar_search_last_active_buffer(ctx,
898 							&end_buffer_offset);
899 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
900 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
901 
902 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
903 		/*
904 		 * The filled part of the overall buffer wraps around; handle
905 		 * all packets up to the buffer end here.  If the last packet
906 		 * wraps around, its tail will be visible after the buffer end
907 		 * because the buffer start pages are mapped there again.
908 		 */
909 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
910 		p = handle_ar_packets(ctx, p, buffer_end);
911 		if (p < buffer_end)
912 			goto error;
913 		/* adjust p to point back into the actual buffer */
914 		p -= AR_BUFFERS * PAGE_SIZE;
915 	}
916 
917 	p = handle_ar_packets(ctx, p, end);
918 	if (p != end) {
919 		if (p > end)
920 			ar_context_abort(ctx, "inconsistent descriptor");
921 		goto error;
922 	}
923 
924 	ctx->pointer = p;
925 	ar_recycle_buffers(ctx, end_buffer_index);
926 
927 	return;
928 
929 error:
930 	ctx->pointer = NULL;
931 }
932 
933 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
934 			   unsigned int descriptors_offset, u32 regs)
935 {
936 	unsigned int i;
937 	dma_addr_t dma_addr;
938 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
939 	struct descriptor *d;
940 
941 	ctx->regs        = regs;
942 	ctx->ohci        = ohci;
943 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
944 
945 	for (i = 0; i < AR_BUFFERS; i++) {
946 		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
947 		if (!ctx->pages[i])
948 			goto out_of_memory;
949 		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
950 					0, PAGE_SIZE, DMA_FROM_DEVICE);
951 		if (dma_mapping_error(ohci->card.device, dma_addr)) {
952 			__free_page(ctx->pages[i]);
953 			ctx->pages[i] = NULL;
954 			goto out_of_memory;
955 		}
956 		set_page_private(ctx->pages[i], dma_addr);
957 	}
958 
959 	for (i = 0; i < AR_BUFFERS; i++)
960 		pages[i]              = ctx->pages[i];
961 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
962 		pages[AR_BUFFERS + i] = ctx->pages[i];
963 	ctx->buffer = vm_map_ram(pages, AR_BUFFERS + AR_WRAPAROUND_PAGES,
964 				 -1, PAGE_KERNEL);
965 	if (!ctx->buffer)
966 		goto out_of_memory;
967 
968 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
969 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
970 
971 	for (i = 0; i < AR_BUFFERS; i++) {
972 		d = &ctx->descriptors[i];
973 		d->req_count      = cpu_to_le16(PAGE_SIZE);
974 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
975 						DESCRIPTOR_STATUS |
976 						DESCRIPTOR_BRANCH_ALWAYS);
977 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
978 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
979 			ar_next_buffer_index(i) * sizeof(struct descriptor));
980 	}
981 
982 	return 0;
983 
984 out_of_memory:
985 	ar_context_release(ctx);
986 
987 	return -ENOMEM;
988 }
989 
990 static void ar_context_run(struct ar_context *ctx)
991 {
992 	unsigned int i;
993 
994 	for (i = 0; i < AR_BUFFERS; i++)
995 		ar_context_link_page(ctx, i);
996 
997 	ctx->pointer = ctx->buffer;
998 
999 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1000 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1001 	flush_writes(ctx->ohci);
1002 }
1003 
1004 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1005 {
1006 	int b, key;
1007 
1008 	b   = (le16_to_cpu(d->control) & DESCRIPTOR_BRANCH_ALWAYS) >> 2;
1009 	key = (le16_to_cpu(d->control) & DESCRIPTOR_KEY_IMMEDIATE) >> 8;
1010 
1011 	/* figure out which descriptor the branch address goes in */
1012 	if (z == 2 && (b == 3 || key == 2))
1013 		return d;
1014 	else
1015 		return d + z - 1;
1016 }
1017 
1018 static void context_tasklet(unsigned long data)
1019 {
1020 	struct context *ctx = (struct context *) data;
1021 	struct descriptor *d, *last;
1022 	u32 address;
1023 	int z;
1024 	struct descriptor_buffer *desc;
1025 
1026 	desc = list_entry(ctx->buffer_list.next,
1027 			struct descriptor_buffer, list);
1028 	last = ctx->last;
1029 	while (last->branch_address != 0) {
1030 		struct descriptor_buffer *old_desc = desc;
1031 		address = le32_to_cpu(last->branch_address);
1032 		z = address & 0xf;
1033 		address &= ~0xf;
1034 
1035 		/* If the branch address points to a buffer outside of the
1036 		 * current buffer, advance to the next buffer. */
1037 		if (address < desc->buffer_bus ||
1038 				address >= desc->buffer_bus + desc->used)
1039 			desc = list_entry(desc->list.next,
1040 					struct descriptor_buffer, list);
1041 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1042 		last = find_branch_descriptor(d, z);
1043 
1044 		if (!ctx->callback(ctx, d, last))
1045 			break;
1046 
1047 		if (old_desc != desc) {
1048 			/* If we've advanced to the next buffer, move the
1049 			 * previous buffer to the free list. */
1050 			unsigned long flags;
1051 			old_desc->used = 0;
1052 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1053 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1054 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1055 		}
1056 		ctx->last = last;
1057 	}
1058 }
1059 
1060 /*
1061  * Allocate a new buffer and add it to the list of free buffers for this
1062  * context.  Must be called with ohci->lock held.
1063  */
1064 static int context_add_buffer(struct context *ctx)
1065 {
1066 	struct descriptor_buffer *desc;
1067 	dma_addr_t uninitialized_var(bus_addr);
1068 	int offset;
1069 
1070 	/*
1071 	 * 16MB of descriptors should be far more than enough for any DMA
1072 	 * program.  This will catch run-away userspace or DoS attacks.
1073 	 */
1074 	if (ctx->total_allocation >= 16*1024*1024)
1075 		return -ENOMEM;
1076 
1077 	desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1078 			&bus_addr, GFP_ATOMIC);
1079 	if (!desc)
1080 		return -ENOMEM;
1081 
1082 	offset = (void *)&desc->buffer - (void *)desc;
1083 	desc->buffer_size = PAGE_SIZE - offset;
1084 	desc->buffer_bus = bus_addr + offset;
1085 	desc->used = 0;
1086 
1087 	list_add_tail(&desc->list, &ctx->buffer_list);
1088 	ctx->total_allocation += PAGE_SIZE;
1089 
1090 	return 0;
1091 }
1092 
1093 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1094 			u32 regs, descriptor_callback_t callback)
1095 {
1096 	ctx->ohci = ohci;
1097 	ctx->regs = regs;
1098 	ctx->total_allocation = 0;
1099 
1100 	INIT_LIST_HEAD(&ctx->buffer_list);
1101 	if (context_add_buffer(ctx) < 0)
1102 		return -ENOMEM;
1103 
1104 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1105 			struct descriptor_buffer, list);
1106 
1107 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1108 	ctx->callback = callback;
1109 
1110 	/*
1111 	 * We put a dummy descriptor in the buffer that has a NULL
1112 	 * branch address and looks like it's been sent.  That way we
1113 	 * have a descriptor to append DMA programs to.
1114 	 */
1115 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1116 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1117 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1118 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1119 	ctx->last = ctx->buffer_tail->buffer;
1120 	ctx->prev = ctx->buffer_tail->buffer;
1121 
1122 	return 0;
1123 }
1124 
1125 static void context_release(struct context *ctx)
1126 {
1127 	struct fw_card *card = &ctx->ohci->card;
1128 	struct descriptor_buffer *desc, *tmp;
1129 
1130 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1131 		dma_free_coherent(card->device, PAGE_SIZE, desc,
1132 			desc->buffer_bus -
1133 			((void *)&desc->buffer - (void *)desc));
1134 }
1135 
1136 /* Must be called with ohci->lock held */
1137 static struct descriptor *context_get_descriptors(struct context *ctx,
1138 						  int z, dma_addr_t *d_bus)
1139 {
1140 	struct descriptor *d = NULL;
1141 	struct descriptor_buffer *desc = ctx->buffer_tail;
1142 
1143 	if (z * sizeof(*d) > desc->buffer_size)
1144 		return NULL;
1145 
1146 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1147 		/* No room for the descriptor in this buffer, so advance to the
1148 		 * next one. */
1149 
1150 		if (desc->list.next == &ctx->buffer_list) {
1151 			/* If there is no free buffer next in the list,
1152 			 * allocate one. */
1153 			if (context_add_buffer(ctx) < 0)
1154 				return NULL;
1155 		}
1156 		desc = list_entry(desc->list.next,
1157 				struct descriptor_buffer, list);
1158 		ctx->buffer_tail = desc;
1159 	}
1160 
1161 	d = desc->buffer + desc->used / sizeof(*d);
1162 	memset(d, 0, z * sizeof(*d));
1163 	*d_bus = desc->buffer_bus + desc->used;
1164 
1165 	return d;
1166 }
1167 
1168 static void context_run(struct context *ctx, u32 extra)
1169 {
1170 	struct fw_ohci *ohci = ctx->ohci;
1171 
1172 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1173 		  le32_to_cpu(ctx->last->branch_address));
1174 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1175 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1176 	ctx->running = true;
1177 	flush_writes(ohci);
1178 }
1179 
1180 static void context_append(struct context *ctx,
1181 			   struct descriptor *d, int z, int extra)
1182 {
1183 	dma_addr_t d_bus;
1184 	struct descriptor_buffer *desc = ctx->buffer_tail;
1185 
1186 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1187 
1188 	desc->used += (z + extra) * sizeof(*d);
1189 
1190 	wmb(); /* finish init of new descriptors before branch_address update */
1191 	ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1192 	ctx->prev = find_branch_descriptor(d, z);
1193 
1194 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1195 	flush_writes(ctx->ohci);
1196 }
1197 
1198 static void context_stop(struct context *ctx)
1199 {
1200 	u32 reg;
1201 	int i;
1202 
1203 	reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1204 	ctx->running = false;
1205 	flush_writes(ctx->ohci);
1206 
1207 	for (i = 0; i < 10; i++) {
1208 		reg = reg_read(ctx->ohci, CONTROL_SET(ctx->regs));
1209 		if ((reg & CONTEXT_ACTIVE) == 0)
1210 			return;
1211 
1212 		mdelay(1);
1213 	}
1214 	fw_error("Error: DMA context still active (0x%08x)\n", reg);
1215 }
1216 
1217 struct driver_data {
1218 	struct fw_packet *packet;
1219 };
1220 
1221 /*
1222  * This function apppends a packet to the DMA queue for transmission.
1223  * Must always be called with the ochi->lock held to ensure proper
1224  * generation handling and locking around packet queue manipulation.
1225  */
1226 static int at_context_queue_packet(struct context *ctx,
1227 				   struct fw_packet *packet)
1228 {
1229 	struct fw_ohci *ohci = ctx->ohci;
1230 	dma_addr_t d_bus, uninitialized_var(payload_bus);
1231 	struct driver_data *driver_data;
1232 	struct descriptor *d, *last;
1233 	__le32 *header;
1234 	int z, tcode;
1235 
1236 	d = context_get_descriptors(ctx, 4, &d_bus);
1237 	if (d == NULL) {
1238 		packet->ack = RCODE_SEND_ERROR;
1239 		return -1;
1240 	}
1241 
1242 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1243 	d[0].res_count = cpu_to_le16(packet->timestamp);
1244 
1245 	/*
1246 	 * The DMA format for asyncronous link packets is different
1247 	 * from the IEEE1394 layout, so shift the fields around
1248 	 * accordingly.
1249 	 */
1250 
1251 	tcode = (packet->header[0] >> 4) & 0x0f;
1252 	header = (__le32 *) &d[1];
1253 	switch (tcode) {
1254 	case TCODE_WRITE_QUADLET_REQUEST:
1255 	case TCODE_WRITE_BLOCK_REQUEST:
1256 	case TCODE_WRITE_RESPONSE:
1257 	case TCODE_READ_QUADLET_REQUEST:
1258 	case TCODE_READ_BLOCK_REQUEST:
1259 	case TCODE_READ_QUADLET_RESPONSE:
1260 	case TCODE_READ_BLOCK_RESPONSE:
1261 	case TCODE_LOCK_REQUEST:
1262 	case TCODE_LOCK_RESPONSE:
1263 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1264 					(packet->speed << 16));
1265 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1266 					(packet->header[0] & 0xffff0000));
1267 		header[2] = cpu_to_le32(packet->header[2]);
1268 
1269 		if (TCODE_IS_BLOCK_PACKET(tcode))
1270 			header[3] = cpu_to_le32(packet->header[3]);
1271 		else
1272 			header[3] = (__force __le32) packet->header[3];
1273 
1274 		d[0].req_count = cpu_to_le16(packet->header_length);
1275 		break;
1276 
1277 	case TCODE_LINK_INTERNAL:
1278 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1279 					(packet->speed << 16));
1280 		header[1] = cpu_to_le32(packet->header[1]);
1281 		header[2] = cpu_to_le32(packet->header[2]);
1282 		d[0].req_count = cpu_to_le16(12);
1283 
1284 		if (is_ping_packet(&packet->header[1]))
1285 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1286 		break;
1287 
1288 	case TCODE_STREAM_DATA:
1289 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1290 					(packet->speed << 16));
1291 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1292 		d[0].req_count = cpu_to_le16(8);
1293 		break;
1294 
1295 	default:
1296 		/* BUG(); */
1297 		packet->ack = RCODE_SEND_ERROR;
1298 		return -1;
1299 	}
1300 
1301 	driver_data = (struct driver_data *) &d[3];
1302 	driver_data->packet = packet;
1303 	packet->driver_data = driver_data;
1304 
1305 	if (packet->payload_length > 0) {
1306 		payload_bus =
1307 			dma_map_single(ohci->card.device, packet->payload,
1308 				       packet->payload_length, DMA_TO_DEVICE);
1309 		if (dma_mapping_error(ohci->card.device, payload_bus)) {
1310 			packet->ack = RCODE_SEND_ERROR;
1311 			return -1;
1312 		}
1313 		packet->payload_bus	= payload_bus;
1314 		packet->payload_mapped	= true;
1315 
1316 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1317 		d[2].data_address = cpu_to_le32(payload_bus);
1318 		last = &d[2];
1319 		z = 3;
1320 	} else {
1321 		last = &d[0];
1322 		z = 2;
1323 	}
1324 
1325 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1326 				     DESCRIPTOR_IRQ_ALWAYS |
1327 				     DESCRIPTOR_BRANCH_ALWAYS);
1328 
1329 	/*
1330 	 * If the controller and packet generations don't match, we need to
1331 	 * bail out and try again.  If IntEvent.busReset is set, the AT context
1332 	 * is halted, so appending to the context and trying to run it is
1333 	 * futile.  Most controllers do the right thing and just flush the AT
1334 	 * queue (per section 7.2.3.2 of the OHCI 1.1 specification), but
1335 	 * some controllers (like a JMicron JMB381 PCI-e) misbehave and wind
1336 	 * up stalling out.  So we just bail out in software and try again
1337 	 * later, and everyone is happy.
1338 	 * FIXME: Test of IntEvent.busReset may no longer be necessary since we
1339 	 *        flush AT queues in bus_reset_tasklet.
1340 	 * FIXME: Document how the locking works.
1341 	 */
1342 	if (ohci->generation != packet->generation ||
1343 	    reg_read(ohci, OHCI1394_IntEventSet) & OHCI1394_busReset) {
1344 		if (packet->payload_mapped)
1345 			dma_unmap_single(ohci->card.device, payload_bus,
1346 					 packet->payload_length, DMA_TO_DEVICE);
1347 		packet->ack = RCODE_GENERATION;
1348 		return -1;
1349 	}
1350 
1351 	context_append(ctx, d, z, 4 - z);
1352 
1353 	if (!ctx->running)
1354 		context_run(ctx, 0);
1355 
1356 	return 0;
1357 }
1358 
1359 static void at_context_flush(struct context *ctx)
1360 {
1361 	tasklet_disable(&ctx->tasklet);
1362 
1363 	ctx->flushing = true;
1364 	context_tasklet((unsigned long)ctx);
1365 	ctx->flushing = false;
1366 
1367 	tasklet_enable(&ctx->tasklet);
1368 }
1369 
1370 static int handle_at_packet(struct context *context,
1371 			    struct descriptor *d,
1372 			    struct descriptor *last)
1373 {
1374 	struct driver_data *driver_data;
1375 	struct fw_packet *packet;
1376 	struct fw_ohci *ohci = context->ohci;
1377 	int evt;
1378 
1379 	if (last->transfer_status == 0 && !context->flushing)
1380 		/* This descriptor isn't done yet, stop iteration. */
1381 		return 0;
1382 
1383 	driver_data = (struct driver_data *) &d[3];
1384 	packet = driver_data->packet;
1385 	if (packet == NULL)
1386 		/* This packet was cancelled, just continue. */
1387 		return 1;
1388 
1389 	if (packet->payload_mapped)
1390 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1391 				 packet->payload_length, DMA_TO_DEVICE);
1392 
1393 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1394 	packet->timestamp = le16_to_cpu(last->res_count);
1395 
1396 	log_ar_at_event('T', packet->speed, packet->header, evt);
1397 
1398 	switch (evt) {
1399 	case OHCI1394_evt_timeout:
1400 		/* Async response transmit timed out. */
1401 		packet->ack = RCODE_CANCELLED;
1402 		break;
1403 
1404 	case OHCI1394_evt_flushed:
1405 		/*
1406 		 * The packet was flushed should give same error as
1407 		 * when we try to use a stale generation count.
1408 		 */
1409 		packet->ack = RCODE_GENERATION;
1410 		break;
1411 
1412 	case OHCI1394_evt_missing_ack:
1413 		if (context->flushing)
1414 			packet->ack = RCODE_GENERATION;
1415 		else {
1416 			/*
1417 			 * Using a valid (current) generation count, but the
1418 			 * node is not on the bus or not sending acks.
1419 			 */
1420 			packet->ack = RCODE_NO_ACK;
1421 		}
1422 		break;
1423 
1424 	case ACK_COMPLETE + 0x10:
1425 	case ACK_PENDING + 0x10:
1426 	case ACK_BUSY_X + 0x10:
1427 	case ACK_BUSY_A + 0x10:
1428 	case ACK_BUSY_B + 0x10:
1429 	case ACK_DATA_ERROR + 0x10:
1430 	case ACK_TYPE_ERROR + 0x10:
1431 		packet->ack = evt - 0x10;
1432 		break;
1433 
1434 	case OHCI1394_evt_no_status:
1435 		if (context->flushing) {
1436 			packet->ack = RCODE_GENERATION;
1437 			break;
1438 		}
1439 		/* fall through */
1440 
1441 	default:
1442 		packet->ack = RCODE_SEND_ERROR;
1443 		break;
1444 	}
1445 
1446 	packet->callback(packet, &ohci->card, packet->ack);
1447 
1448 	return 1;
1449 }
1450 
1451 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1452 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1453 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1454 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1455 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
1456 
1457 static void handle_local_rom(struct fw_ohci *ohci,
1458 			     struct fw_packet *packet, u32 csr)
1459 {
1460 	struct fw_packet response;
1461 	int tcode, length, i;
1462 
1463 	tcode = HEADER_GET_TCODE(packet->header[0]);
1464 	if (TCODE_IS_BLOCK_PACKET(tcode))
1465 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1466 	else
1467 		length = 4;
1468 
1469 	i = csr - CSR_CONFIG_ROM;
1470 	if (i + length > CONFIG_ROM_SIZE) {
1471 		fw_fill_response(&response, packet->header,
1472 				 RCODE_ADDRESS_ERROR, NULL, 0);
1473 	} else if (!TCODE_IS_READ_REQUEST(tcode)) {
1474 		fw_fill_response(&response, packet->header,
1475 				 RCODE_TYPE_ERROR, NULL, 0);
1476 	} else {
1477 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1478 				 (void *) ohci->config_rom + i, length);
1479 	}
1480 
1481 	fw_core_handle_response(&ohci->card, &response);
1482 }
1483 
1484 static void handle_local_lock(struct fw_ohci *ohci,
1485 			      struct fw_packet *packet, u32 csr)
1486 {
1487 	struct fw_packet response;
1488 	int tcode, length, ext_tcode, sel, try;
1489 	__be32 *payload, lock_old;
1490 	u32 lock_arg, lock_data;
1491 
1492 	tcode = HEADER_GET_TCODE(packet->header[0]);
1493 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1494 	payload = packet->payload;
1495 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1496 
1497 	if (tcode == TCODE_LOCK_REQUEST &&
1498 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1499 		lock_arg = be32_to_cpu(payload[0]);
1500 		lock_data = be32_to_cpu(payload[1]);
1501 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1502 		lock_arg = 0;
1503 		lock_data = 0;
1504 	} else {
1505 		fw_fill_response(&response, packet->header,
1506 				 RCODE_TYPE_ERROR, NULL, 0);
1507 		goto out;
1508 	}
1509 
1510 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1511 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1512 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1513 	reg_write(ohci, OHCI1394_CSRControl, sel);
1514 
1515 	for (try = 0; try < 20; try++)
1516 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1517 			lock_old = cpu_to_be32(reg_read(ohci,
1518 							OHCI1394_CSRData));
1519 			fw_fill_response(&response, packet->header,
1520 					 RCODE_COMPLETE,
1521 					 &lock_old, sizeof(lock_old));
1522 			goto out;
1523 		}
1524 
1525 	fw_error("swap not done (CSR lock timeout)\n");
1526 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1527 
1528  out:
1529 	fw_core_handle_response(&ohci->card, &response);
1530 }
1531 
1532 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1533 {
1534 	u64 offset, csr;
1535 
1536 	if (ctx == &ctx->ohci->at_request_ctx) {
1537 		packet->ack = ACK_PENDING;
1538 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1539 	}
1540 
1541 	offset =
1542 		((unsigned long long)
1543 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1544 		packet->header[2];
1545 	csr = offset - CSR_REGISTER_BASE;
1546 
1547 	/* Handle config rom reads. */
1548 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1549 		handle_local_rom(ctx->ohci, packet, csr);
1550 	else switch (csr) {
1551 	case CSR_BUS_MANAGER_ID:
1552 	case CSR_BANDWIDTH_AVAILABLE:
1553 	case CSR_CHANNELS_AVAILABLE_HI:
1554 	case CSR_CHANNELS_AVAILABLE_LO:
1555 		handle_local_lock(ctx->ohci, packet, csr);
1556 		break;
1557 	default:
1558 		if (ctx == &ctx->ohci->at_request_ctx)
1559 			fw_core_handle_request(&ctx->ohci->card, packet);
1560 		else
1561 			fw_core_handle_response(&ctx->ohci->card, packet);
1562 		break;
1563 	}
1564 
1565 	if (ctx == &ctx->ohci->at_response_ctx) {
1566 		packet->ack = ACK_COMPLETE;
1567 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1568 	}
1569 }
1570 
1571 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1572 {
1573 	unsigned long flags;
1574 	int ret;
1575 
1576 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1577 
1578 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1579 	    ctx->ohci->generation == packet->generation) {
1580 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1581 		handle_local_request(ctx, packet);
1582 		return;
1583 	}
1584 
1585 	ret = at_context_queue_packet(ctx, packet);
1586 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1587 
1588 	if (ret < 0)
1589 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1590 
1591 }
1592 
1593 static u32 cycle_timer_ticks(u32 cycle_timer)
1594 {
1595 	u32 ticks;
1596 
1597 	ticks = cycle_timer & 0xfff;
1598 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1599 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1600 
1601 	return ticks;
1602 }
1603 
1604 /*
1605  * Some controllers exhibit one or more of the following bugs when updating the
1606  * iso cycle timer register:
1607  *  - When the lowest six bits are wrapping around to zero, a read that happens
1608  *    at the same time will return garbage in the lowest ten bits.
1609  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1610  *    not incremented for about 60 ns.
1611  *  - Occasionally, the entire register reads zero.
1612  *
1613  * To catch these, we read the register three times and ensure that the
1614  * difference between each two consecutive reads is approximately the same, i.e.
1615  * less than twice the other.  Furthermore, any negative difference indicates an
1616  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1617  * execute, so we have enough precision to compute the ratio of the differences.)
1618  */
1619 static u32 get_cycle_time(struct fw_ohci *ohci)
1620 {
1621 	u32 c0, c1, c2;
1622 	u32 t0, t1, t2;
1623 	s32 diff01, diff12;
1624 	int i;
1625 
1626 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1627 
1628 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1629 		i = 0;
1630 		c1 = c2;
1631 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1632 		do {
1633 			c0 = c1;
1634 			c1 = c2;
1635 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1636 			t0 = cycle_timer_ticks(c0);
1637 			t1 = cycle_timer_ticks(c1);
1638 			t2 = cycle_timer_ticks(c2);
1639 			diff01 = t1 - t0;
1640 			diff12 = t2 - t1;
1641 		} while ((diff01 <= 0 || diff12 <= 0 ||
1642 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1643 			 && i++ < 20);
1644 	}
1645 
1646 	return c2;
1647 }
1648 
1649 /*
1650  * This function has to be called at least every 64 seconds.  The bus_time
1651  * field stores not only the upper 25 bits of the BUS_TIME register but also
1652  * the most significant bit of the cycle timer in bit 6 so that we can detect
1653  * changes in this bit.
1654  */
1655 static u32 update_bus_time(struct fw_ohci *ohci)
1656 {
1657 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1658 
1659 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1660 		ohci->bus_time += 0x40;
1661 
1662 	return ohci->bus_time | cycle_time_seconds;
1663 }
1664 
1665 static void bus_reset_tasklet(unsigned long data)
1666 {
1667 	struct fw_ohci *ohci = (struct fw_ohci *)data;
1668 	int self_id_count, i, j, reg;
1669 	int generation, new_generation;
1670 	unsigned long flags;
1671 	void *free_rom = NULL;
1672 	dma_addr_t free_rom_bus = 0;
1673 	bool is_new_root;
1674 
1675 	reg = reg_read(ohci, OHCI1394_NodeID);
1676 	if (!(reg & OHCI1394_NodeID_idValid)) {
1677 		fw_notify("node ID not valid, new bus reset in progress\n");
1678 		return;
1679 	}
1680 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1681 		fw_notify("malconfigured bus\n");
1682 		return;
1683 	}
1684 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1685 			       OHCI1394_NodeID_nodeNumber);
1686 
1687 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1688 	if (!(ohci->is_root && is_new_root))
1689 		reg_write(ohci, OHCI1394_LinkControlSet,
1690 			  OHCI1394_LinkControl_cycleMaster);
1691 	ohci->is_root = is_new_root;
1692 
1693 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1694 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1695 		fw_notify("inconsistent self IDs\n");
1696 		return;
1697 	}
1698 	/*
1699 	 * The count in the SelfIDCount register is the number of
1700 	 * bytes in the self ID receive buffer.  Since we also receive
1701 	 * the inverted quadlets and a header quadlet, we shift one
1702 	 * bit extra to get the actual number of self IDs.
1703 	 */
1704 	self_id_count = (reg >> 3) & 0xff;
1705 	if (self_id_count == 0 || self_id_count > 252) {
1706 		fw_notify("inconsistent self IDs\n");
1707 		return;
1708 	}
1709 	generation = (cond_le32_to_cpu(ohci->self_id_cpu[0]) >> 16) & 0xff;
1710 	rmb();
1711 
1712 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1713 		if (ohci->self_id_cpu[i] != ~ohci->self_id_cpu[i + 1]) {
1714 			fw_notify("inconsistent self IDs\n");
1715 			return;
1716 		}
1717 		ohci->self_id_buffer[j] =
1718 				cond_le32_to_cpu(ohci->self_id_cpu[i]);
1719 	}
1720 	rmb();
1721 
1722 	/*
1723 	 * Check the consistency of the self IDs we just read.  The
1724 	 * problem we face is that a new bus reset can start while we
1725 	 * read out the self IDs from the DMA buffer. If this happens,
1726 	 * the DMA buffer will be overwritten with new self IDs and we
1727 	 * will read out inconsistent data.  The OHCI specification
1728 	 * (section 11.2) recommends a technique similar to
1729 	 * linux/seqlock.h, where we remember the generation of the
1730 	 * self IDs in the buffer before reading them out and compare
1731 	 * it to the current generation after reading them out.  If
1732 	 * the two generations match we know we have a consistent set
1733 	 * of self IDs.
1734 	 */
1735 
1736 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1737 	if (new_generation != generation) {
1738 		fw_notify("recursive bus reset detected, "
1739 			  "discarding self ids\n");
1740 		return;
1741 	}
1742 
1743 	/* FIXME: Document how the locking works. */
1744 	spin_lock_irqsave(&ohci->lock, flags);
1745 
1746 	ohci->generation = -1; /* prevent AT packet queueing */
1747 	context_stop(&ohci->at_request_ctx);
1748 	context_stop(&ohci->at_response_ctx);
1749 
1750 	spin_unlock_irqrestore(&ohci->lock, flags);
1751 
1752 	/*
1753 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
1754 	 * packets in the AT queues and software needs to drain them.
1755 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
1756 	 */
1757 	at_context_flush(&ohci->at_request_ctx);
1758 	at_context_flush(&ohci->at_response_ctx);
1759 
1760 	spin_lock_irqsave(&ohci->lock, flags);
1761 
1762 	ohci->generation = generation;
1763 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
1764 
1765 	if (ohci->quirks & QUIRK_RESET_PACKET)
1766 		ohci->request_generation = generation;
1767 
1768 	/*
1769 	 * This next bit is unrelated to the AT context stuff but we
1770 	 * have to do it under the spinlock also.  If a new config rom
1771 	 * was set up before this reset, the old one is now no longer
1772 	 * in use and we can free it. Update the config rom pointers
1773 	 * to point to the current config rom and clear the
1774 	 * next_config_rom pointer so a new update can take place.
1775 	 */
1776 
1777 	if (ohci->next_config_rom != NULL) {
1778 		if (ohci->next_config_rom != ohci->config_rom) {
1779 			free_rom      = ohci->config_rom;
1780 			free_rom_bus  = ohci->config_rom_bus;
1781 		}
1782 		ohci->config_rom      = ohci->next_config_rom;
1783 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
1784 		ohci->next_config_rom = NULL;
1785 
1786 		/*
1787 		 * Restore config_rom image and manually update
1788 		 * config_rom registers.  Writing the header quadlet
1789 		 * will indicate that the config rom is ready, so we
1790 		 * do that last.
1791 		 */
1792 		reg_write(ohci, OHCI1394_BusOptions,
1793 			  be32_to_cpu(ohci->config_rom[2]));
1794 		ohci->config_rom[0] = ohci->next_header;
1795 		reg_write(ohci, OHCI1394_ConfigROMhdr,
1796 			  be32_to_cpu(ohci->next_header));
1797 	}
1798 
1799 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
1800 	reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
1801 	reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
1802 #endif
1803 
1804 	spin_unlock_irqrestore(&ohci->lock, flags);
1805 
1806 	if (free_rom)
1807 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
1808 				  free_rom, free_rom_bus);
1809 
1810 	log_selfids(ohci->node_id, generation,
1811 		    self_id_count, ohci->self_id_buffer);
1812 
1813 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
1814 				 self_id_count, ohci->self_id_buffer,
1815 				 ohci->csr_state_setclear_abdicate);
1816 	ohci->csr_state_setclear_abdicate = false;
1817 }
1818 
1819 static irqreturn_t irq_handler(int irq, void *data)
1820 {
1821 	struct fw_ohci *ohci = data;
1822 	u32 event, iso_event;
1823 	int i;
1824 
1825 	event = reg_read(ohci, OHCI1394_IntEventClear);
1826 
1827 	if (!event || !~event)
1828 		return IRQ_NONE;
1829 
1830 	/*
1831 	 * busReset and postedWriteErr must not be cleared yet
1832 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
1833 	 */
1834 	reg_write(ohci, OHCI1394_IntEventClear,
1835 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
1836 	log_irqs(event);
1837 
1838 	if (event & OHCI1394_selfIDComplete)
1839 		tasklet_schedule(&ohci->bus_reset_tasklet);
1840 
1841 	if (event & OHCI1394_RQPkt)
1842 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
1843 
1844 	if (event & OHCI1394_RSPkt)
1845 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
1846 
1847 	if (event & OHCI1394_reqTxComplete)
1848 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
1849 
1850 	if (event & OHCI1394_respTxComplete)
1851 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
1852 
1853 	if (event & OHCI1394_isochRx) {
1854 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
1855 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
1856 
1857 		while (iso_event) {
1858 			i = ffs(iso_event) - 1;
1859 			tasklet_schedule(
1860 				&ohci->ir_context_list[i].context.tasklet);
1861 			iso_event &= ~(1 << i);
1862 		}
1863 	}
1864 
1865 	if (event & OHCI1394_isochTx) {
1866 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
1867 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
1868 
1869 		while (iso_event) {
1870 			i = ffs(iso_event) - 1;
1871 			tasklet_schedule(
1872 				&ohci->it_context_list[i].context.tasklet);
1873 			iso_event &= ~(1 << i);
1874 		}
1875 	}
1876 
1877 	if (unlikely(event & OHCI1394_regAccessFail))
1878 		fw_error("Register access failure - "
1879 			 "please notify linux1394-devel@lists.sf.net\n");
1880 
1881 	if (unlikely(event & OHCI1394_postedWriteErr)) {
1882 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
1883 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
1884 		reg_write(ohci, OHCI1394_IntEventClear,
1885 			  OHCI1394_postedWriteErr);
1886 		fw_error("PCI posted write error\n");
1887 	}
1888 
1889 	if (unlikely(event & OHCI1394_cycleTooLong)) {
1890 		if (printk_ratelimit())
1891 			fw_notify("isochronous cycle too long\n");
1892 		reg_write(ohci, OHCI1394_LinkControlSet,
1893 			  OHCI1394_LinkControl_cycleMaster);
1894 	}
1895 
1896 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
1897 		/*
1898 		 * We need to clear this event bit in order to make
1899 		 * cycleMatch isochronous I/O work.  In theory we should
1900 		 * stop active cycleMatch iso contexts now and restart
1901 		 * them at least two cycles later.  (FIXME?)
1902 		 */
1903 		if (printk_ratelimit())
1904 			fw_notify("isochronous cycle inconsistent\n");
1905 	}
1906 
1907 	if (event & OHCI1394_cycle64Seconds) {
1908 		spin_lock(&ohci->lock);
1909 		update_bus_time(ohci);
1910 		spin_unlock(&ohci->lock);
1911 	} else
1912 		flush_writes(ohci);
1913 
1914 	return IRQ_HANDLED;
1915 }
1916 
1917 static int software_reset(struct fw_ohci *ohci)
1918 {
1919 	int i;
1920 
1921 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
1922 
1923 	for (i = 0; i < OHCI_LOOP_COUNT; i++) {
1924 		if ((reg_read(ohci, OHCI1394_HCControlSet) &
1925 		     OHCI1394_HCControl_softReset) == 0)
1926 			return 0;
1927 		msleep(1);
1928 	}
1929 
1930 	return -EBUSY;
1931 }
1932 
1933 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
1934 {
1935 	size_t size = length * 4;
1936 
1937 	memcpy(dest, src, size);
1938 	if (size < CONFIG_ROM_SIZE)
1939 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
1940 }
1941 
1942 static int configure_1394a_enhancements(struct fw_ohci *ohci)
1943 {
1944 	bool enable_1394a;
1945 	int ret, clear, set, offset;
1946 
1947 	/* Check if the driver should configure link and PHY. */
1948 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
1949 	      OHCI1394_HCControl_programPhyEnable))
1950 		return 0;
1951 
1952 	/* Paranoia: check whether the PHY supports 1394a, too. */
1953 	enable_1394a = false;
1954 	ret = read_phy_reg(ohci, 2);
1955 	if (ret < 0)
1956 		return ret;
1957 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
1958 		ret = read_paged_phy_reg(ohci, 1, 8);
1959 		if (ret < 0)
1960 			return ret;
1961 		if (ret >= 1)
1962 			enable_1394a = true;
1963 	}
1964 
1965 	if (ohci->quirks & QUIRK_NO_1394A)
1966 		enable_1394a = false;
1967 
1968 	/* Configure PHY and link consistently. */
1969 	if (enable_1394a) {
1970 		clear = 0;
1971 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
1972 	} else {
1973 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
1974 		set = 0;
1975 	}
1976 	ret = update_phy_reg(ohci, 5, clear, set);
1977 	if (ret < 0)
1978 		return ret;
1979 
1980 	if (enable_1394a)
1981 		offset = OHCI1394_HCControlSet;
1982 	else
1983 		offset = OHCI1394_HCControlClear;
1984 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
1985 
1986 	/* Clean up: configuration has been taken care of. */
1987 	reg_write(ohci, OHCI1394_HCControlClear,
1988 		  OHCI1394_HCControl_programPhyEnable);
1989 
1990 	return 0;
1991 }
1992 
1993 static int ohci_enable(struct fw_card *card,
1994 		       const __be32 *config_rom, size_t length)
1995 {
1996 	struct fw_ohci *ohci = fw_ohci(card);
1997 	struct pci_dev *dev = to_pci_dev(card->device);
1998 	u32 lps, seconds, version, irqs;
1999 	int i, ret;
2000 
2001 	if (software_reset(ohci)) {
2002 		fw_error("Failed to reset ohci card.\n");
2003 		return -EBUSY;
2004 	}
2005 
2006 	/*
2007 	 * Now enable LPS, which we need in order to start accessing
2008 	 * most of the registers.  In fact, on some cards (ALI M5251),
2009 	 * accessing registers in the SClk domain without LPS enabled
2010 	 * will lock up the machine.  Wait 50msec to make sure we have
2011 	 * full link enabled.  However, with some cards (well, at least
2012 	 * a JMicron PCIe card), we have to try again sometimes.
2013 	 */
2014 	reg_write(ohci, OHCI1394_HCControlSet,
2015 		  OHCI1394_HCControl_LPS |
2016 		  OHCI1394_HCControl_postedWriteEnable);
2017 	flush_writes(ohci);
2018 
2019 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2020 		msleep(50);
2021 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2022 		      OHCI1394_HCControl_LPS;
2023 	}
2024 
2025 	if (!lps) {
2026 		fw_error("Failed to set Link Power Status\n");
2027 		return -EIO;
2028 	}
2029 
2030 	reg_write(ohci, OHCI1394_HCControlClear,
2031 		  OHCI1394_HCControl_noByteSwapData);
2032 
2033 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2034 	reg_write(ohci, OHCI1394_LinkControlSet,
2035 		  OHCI1394_LinkControl_rcvSelfID |
2036 		  OHCI1394_LinkControl_rcvPhyPkt |
2037 		  OHCI1394_LinkControl_cycleTimerEnable |
2038 		  OHCI1394_LinkControl_cycleMaster);
2039 
2040 	reg_write(ohci, OHCI1394_ATRetries,
2041 		  OHCI1394_MAX_AT_REQ_RETRIES |
2042 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2043 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2044 		  (200 << 16));
2045 
2046 	seconds = lower_32_bits(get_seconds());
2047 	reg_write(ohci, OHCI1394_IsochronousCycleTimer, seconds << 25);
2048 	ohci->bus_time = seconds & ~0x3f;
2049 
2050 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2051 	if (version >= OHCI_VERSION_1_1) {
2052 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2053 			  0xfffffffe);
2054 		card->broadcast_channel_auto_allocated = true;
2055 	}
2056 
2057 	/* Get implemented bits of the priority arbitration request counter. */
2058 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2059 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2060 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2061 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2062 
2063 	ar_context_run(&ohci->ar_request_ctx);
2064 	ar_context_run(&ohci->ar_response_ctx);
2065 
2066 	reg_write(ohci, OHCI1394_PhyUpperBound, 0x00010000);
2067 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2068 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2069 
2070 	ret = configure_1394a_enhancements(ohci);
2071 	if (ret < 0)
2072 		return ret;
2073 
2074 	/* Activate link_on bit and contender bit in our self ID packets.*/
2075 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2076 	if (ret < 0)
2077 		return ret;
2078 
2079 	/*
2080 	 * When the link is not yet enabled, the atomic config rom
2081 	 * update mechanism described below in ohci_set_config_rom()
2082 	 * is not active.  We have to update ConfigRomHeader and
2083 	 * BusOptions manually, and the write to ConfigROMmap takes
2084 	 * effect immediately.  We tie this to the enabling of the
2085 	 * link, so we have a valid config rom before enabling - the
2086 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2087 	 * values before enabling.
2088 	 *
2089 	 * However, when the ConfigROMmap is written, some controllers
2090 	 * always read back quadlets 0 and 2 from the config rom to
2091 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2092 	 * They shouldn't do that in this initial case where the link
2093 	 * isn't enabled.  This means we have to use the same
2094 	 * workaround here, setting the bus header to 0 and then write
2095 	 * the right values in the bus reset tasklet.
2096 	 */
2097 
2098 	if (config_rom) {
2099 		ohci->next_config_rom =
2100 			dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2101 					   &ohci->next_config_rom_bus,
2102 					   GFP_KERNEL);
2103 		if (ohci->next_config_rom == NULL)
2104 			return -ENOMEM;
2105 
2106 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2107 	} else {
2108 		/*
2109 		 * In the suspend case, config_rom is NULL, which
2110 		 * means that we just reuse the old config rom.
2111 		 */
2112 		ohci->next_config_rom = ohci->config_rom;
2113 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2114 	}
2115 
2116 	ohci->next_header = ohci->next_config_rom[0];
2117 	ohci->next_config_rom[0] = 0;
2118 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2119 	reg_write(ohci, OHCI1394_BusOptions,
2120 		  be32_to_cpu(ohci->next_config_rom[2]));
2121 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2122 
2123 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2124 
2125 	if (!(ohci->quirks & QUIRK_NO_MSI))
2126 		pci_enable_msi(dev);
2127 	if (request_irq(dev->irq, irq_handler,
2128 			pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
2129 			ohci_driver_name, ohci)) {
2130 		fw_error("Failed to allocate interrupt %d.\n", dev->irq);
2131 		pci_disable_msi(dev);
2132 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2133 				  ohci->config_rom, ohci->config_rom_bus);
2134 		return -EIO;
2135 	}
2136 
2137 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2138 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2139 		OHCI1394_isochTx | OHCI1394_isochRx |
2140 		OHCI1394_postedWriteErr |
2141 		OHCI1394_selfIDComplete |
2142 		OHCI1394_regAccessFail |
2143 		OHCI1394_cycle64Seconds |
2144 		OHCI1394_cycleInconsistent | OHCI1394_cycleTooLong |
2145 		OHCI1394_masterIntEnable;
2146 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2147 		irqs |= OHCI1394_busReset;
2148 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2149 
2150 	reg_write(ohci, OHCI1394_HCControlSet,
2151 		  OHCI1394_HCControl_linkEnable |
2152 		  OHCI1394_HCControl_BIBimageValid);
2153 	flush_writes(ohci);
2154 
2155 	/* We are ready to go, reset bus to finish initialization. */
2156 	fw_schedule_bus_reset(&ohci->card, false, true);
2157 
2158 	return 0;
2159 }
2160 
2161 static int ohci_set_config_rom(struct fw_card *card,
2162 			       const __be32 *config_rom, size_t length)
2163 {
2164 	struct fw_ohci *ohci;
2165 	unsigned long flags;
2166 	int ret = -EBUSY;
2167 	__be32 *next_config_rom;
2168 	dma_addr_t uninitialized_var(next_config_rom_bus);
2169 
2170 	ohci = fw_ohci(card);
2171 
2172 	/*
2173 	 * When the OHCI controller is enabled, the config rom update
2174 	 * mechanism is a bit tricky, but easy enough to use.  See
2175 	 * section 5.5.6 in the OHCI specification.
2176 	 *
2177 	 * The OHCI controller caches the new config rom address in a
2178 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2179 	 * for the changes to take place.  When the bus reset is
2180 	 * detected, the controller loads the new values for the
2181 	 * ConfigRomHeader and BusOptions registers from the specified
2182 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2183 	 * shadow register. All automatically and atomically.
2184 	 *
2185 	 * Now, there's a twist to this story.  The automatic load of
2186 	 * ConfigRomHeader and BusOptions doesn't honor the
2187 	 * noByteSwapData bit, so with a be32 config rom, the
2188 	 * controller will load be32 values in to these registers
2189 	 * during the atomic update, even on litte endian
2190 	 * architectures.  The workaround we use is to put a 0 in the
2191 	 * header quadlet; 0 is endian agnostic and means that the
2192 	 * config rom isn't ready yet.  In the bus reset tasklet we
2193 	 * then set up the real values for the two registers.
2194 	 *
2195 	 * We use ohci->lock to avoid racing with the code that sets
2196 	 * ohci->next_config_rom to NULL (see bus_reset_tasklet).
2197 	 */
2198 
2199 	next_config_rom =
2200 		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2201 				   &next_config_rom_bus, GFP_KERNEL);
2202 	if (next_config_rom == NULL)
2203 		return -ENOMEM;
2204 
2205 	spin_lock_irqsave(&ohci->lock, flags);
2206 
2207 	if (ohci->next_config_rom == NULL) {
2208 		ohci->next_config_rom = next_config_rom;
2209 		ohci->next_config_rom_bus = next_config_rom_bus;
2210 
2211 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2212 
2213 		ohci->next_header = config_rom[0];
2214 		ohci->next_config_rom[0] = 0;
2215 
2216 		reg_write(ohci, OHCI1394_ConfigROMmap,
2217 			  ohci->next_config_rom_bus);
2218 		ret = 0;
2219 	}
2220 
2221 	spin_unlock_irqrestore(&ohci->lock, flags);
2222 
2223 	/*
2224 	 * Now initiate a bus reset to have the changes take
2225 	 * effect. We clean up the old config rom memory and DMA
2226 	 * mappings in the bus reset tasklet, since the OHCI
2227 	 * controller could need to access it before the bus reset
2228 	 * takes effect.
2229 	 */
2230 	if (ret == 0)
2231 		fw_schedule_bus_reset(&ohci->card, true, true);
2232 	else
2233 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2234 				  next_config_rom, next_config_rom_bus);
2235 
2236 	return ret;
2237 }
2238 
2239 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2240 {
2241 	struct fw_ohci *ohci = fw_ohci(card);
2242 
2243 	at_context_transmit(&ohci->at_request_ctx, packet);
2244 }
2245 
2246 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2247 {
2248 	struct fw_ohci *ohci = fw_ohci(card);
2249 
2250 	at_context_transmit(&ohci->at_response_ctx, packet);
2251 }
2252 
2253 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2254 {
2255 	struct fw_ohci *ohci = fw_ohci(card);
2256 	struct context *ctx = &ohci->at_request_ctx;
2257 	struct driver_data *driver_data = packet->driver_data;
2258 	int ret = -ENOENT;
2259 
2260 	tasklet_disable(&ctx->tasklet);
2261 
2262 	if (packet->ack != 0)
2263 		goto out;
2264 
2265 	if (packet->payload_mapped)
2266 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2267 				 packet->payload_length, DMA_TO_DEVICE);
2268 
2269 	log_ar_at_event('T', packet->speed, packet->header, 0x20);
2270 	driver_data->packet = NULL;
2271 	packet->ack = RCODE_CANCELLED;
2272 	packet->callback(packet, &ohci->card, packet->ack);
2273 	ret = 0;
2274  out:
2275 	tasklet_enable(&ctx->tasklet);
2276 
2277 	return ret;
2278 }
2279 
2280 static int ohci_enable_phys_dma(struct fw_card *card,
2281 				int node_id, int generation)
2282 {
2283 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
2284 	return 0;
2285 #else
2286 	struct fw_ohci *ohci = fw_ohci(card);
2287 	unsigned long flags;
2288 	int n, ret = 0;
2289 
2290 	/*
2291 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2292 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2293 	 */
2294 
2295 	spin_lock_irqsave(&ohci->lock, flags);
2296 
2297 	if (ohci->generation != generation) {
2298 		ret = -ESTALE;
2299 		goto out;
2300 	}
2301 
2302 	/*
2303 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2304 	 * enabled for _all_ nodes on remote buses.
2305 	 */
2306 
2307 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2308 	if (n < 32)
2309 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2310 	else
2311 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2312 
2313 	flush_writes(ohci);
2314  out:
2315 	spin_unlock_irqrestore(&ohci->lock, flags);
2316 
2317 	return ret;
2318 #endif /* CONFIG_FIREWIRE_OHCI_REMOTE_DMA */
2319 }
2320 
2321 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2322 {
2323 	struct fw_ohci *ohci = fw_ohci(card);
2324 	unsigned long flags;
2325 	u32 value;
2326 
2327 	switch (csr_offset) {
2328 	case CSR_STATE_CLEAR:
2329 	case CSR_STATE_SET:
2330 		if (ohci->is_root &&
2331 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2332 		     OHCI1394_LinkControl_cycleMaster))
2333 			value = CSR_STATE_BIT_CMSTR;
2334 		else
2335 			value = 0;
2336 		if (ohci->csr_state_setclear_abdicate)
2337 			value |= CSR_STATE_BIT_ABDICATE;
2338 
2339 		return value;
2340 
2341 	case CSR_NODE_IDS:
2342 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2343 
2344 	case CSR_CYCLE_TIME:
2345 		return get_cycle_time(ohci);
2346 
2347 	case CSR_BUS_TIME:
2348 		/*
2349 		 * We might be called just after the cycle timer has wrapped
2350 		 * around but just before the cycle64Seconds handler, so we
2351 		 * better check here, too, if the bus time needs to be updated.
2352 		 */
2353 		spin_lock_irqsave(&ohci->lock, flags);
2354 		value = update_bus_time(ohci);
2355 		spin_unlock_irqrestore(&ohci->lock, flags);
2356 		return value;
2357 
2358 	case CSR_BUSY_TIMEOUT:
2359 		value = reg_read(ohci, OHCI1394_ATRetries);
2360 		return (value >> 4) & 0x0ffff00f;
2361 
2362 	case CSR_PRIORITY_BUDGET:
2363 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2364 			(ohci->pri_req_max << 8);
2365 
2366 	default:
2367 		WARN_ON(1);
2368 		return 0;
2369 	}
2370 }
2371 
2372 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2373 {
2374 	struct fw_ohci *ohci = fw_ohci(card);
2375 	unsigned long flags;
2376 
2377 	switch (csr_offset) {
2378 	case CSR_STATE_CLEAR:
2379 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2380 			reg_write(ohci, OHCI1394_LinkControlClear,
2381 				  OHCI1394_LinkControl_cycleMaster);
2382 			flush_writes(ohci);
2383 		}
2384 		if (value & CSR_STATE_BIT_ABDICATE)
2385 			ohci->csr_state_setclear_abdicate = false;
2386 		break;
2387 
2388 	case CSR_STATE_SET:
2389 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2390 			reg_write(ohci, OHCI1394_LinkControlSet,
2391 				  OHCI1394_LinkControl_cycleMaster);
2392 			flush_writes(ohci);
2393 		}
2394 		if (value & CSR_STATE_BIT_ABDICATE)
2395 			ohci->csr_state_setclear_abdicate = true;
2396 		break;
2397 
2398 	case CSR_NODE_IDS:
2399 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2400 		flush_writes(ohci);
2401 		break;
2402 
2403 	case CSR_CYCLE_TIME:
2404 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2405 		reg_write(ohci, OHCI1394_IntEventSet,
2406 			  OHCI1394_cycleInconsistent);
2407 		flush_writes(ohci);
2408 		break;
2409 
2410 	case CSR_BUS_TIME:
2411 		spin_lock_irqsave(&ohci->lock, flags);
2412 		ohci->bus_time = (ohci->bus_time & 0x7f) | (value & ~0x7f);
2413 		spin_unlock_irqrestore(&ohci->lock, flags);
2414 		break;
2415 
2416 	case CSR_BUSY_TIMEOUT:
2417 		value = (value & 0xf) | ((value & 0xf) << 4) |
2418 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2419 		reg_write(ohci, OHCI1394_ATRetries, value);
2420 		flush_writes(ohci);
2421 		break;
2422 
2423 	case CSR_PRIORITY_BUDGET:
2424 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2425 		flush_writes(ohci);
2426 		break;
2427 
2428 	default:
2429 		WARN_ON(1);
2430 		break;
2431 	}
2432 }
2433 
2434 static void copy_iso_headers(struct iso_context *ctx, void *p)
2435 {
2436 	int i = ctx->header_length;
2437 
2438 	if (i + ctx->base.header_size > PAGE_SIZE)
2439 		return;
2440 
2441 	/*
2442 	 * The iso header is byteswapped to little endian by
2443 	 * the controller, but the remaining header quadlets
2444 	 * are big endian.  We want to present all the headers
2445 	 * as big endian, so we have to swap the first quadlet.
2446 	 */
2447 	if (ctx->base.header_size > 0)
2448 		*(u32 *) (ctx->header + i) = __swab32(*(u32 *) (p + 4));
2449 	if (ctx->base.header_size > 4)
2450 		*(u32 *) (ctx->header + i + 4) = __swab32(*(u32 *) p);
2451 	if (ctx->base.header_size > 8)
2452 		memcpy(ctx->header + i + 8, p + 8, ctx->base.header_size - 8);
2453 	ctx->header_length += ctx->base.header_size;
2454 }
2455 
2456 static int handle_ir_packet_per_buffer(struct context *context,
2457 				       struct descriptor *d,
2458 				       struct descriptor *last)
2459 {
2460 	struct iso_context *ctx =
2461 		container_of(context, struct iso_context, context);
2462 	struct descriptor *pd;
2463 	__le32 *ir_header;
2464 	void *p;
2465 
2466 	for (pd = d; pd <= last; pd++)
2467 		if (pd->transfer_status)
2468 			break;
2469 	if (pd > last)
2470 		/* Descriptor(s) not done yet, stop iteration */
2471 		return 0;
2472 
2473 	p = last + 1;
2474 	copy_iso_headers(ctx, p);
2475 
2476 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
2477 		ir_header = (__le32 *) p;
2478 		ctx->base.callback.sc(&ctx->base,
2479 				      le32_to_cpu(ir_header[0]) & 0xffff,
2480 				      ctx->header_length, ctx->header,
2481 				      ctx->base.callback_data);
2482 		ctx->header_length = 0;
2483 	}
2484 
2485 	return 1;
2486 }
2487 
2488 /* d == last because each descriptor block is only a single descriptor. */
2489 static int handle_ir_buffer_fill(struct context *context,
2490 				 struct descriptor *d,
2491 				 struct descriptor *last)
2492 {
2493 	struct iso_context *ctx =
2494 		container_of(context, struct iso_context, context);
2495 
2496 	if (!last->transfer_status)
2497 		/* Descriptor(s) not done yet, stop iteration */
2498 		return 0;
2499 
2500 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS)
2501 		ctx->base.callback.mc(&ctx->base,
2502 				      le32_to_cpu(last->data_address) +
2503 				      le16_to_cpu(last->req_count) -
2504 				      le16_to_cpu(last->res_count),
2505 				      ctx->base.callback_data);
2506 
2507 	return 1;
2508 }
2509 
2510 static int handle_it_packet(struct context *context,
2511 			    struct descriptor *d,
2512 			    struct descriptor *last)
2513 {
2514 	struct iso_context *ctx =
2515 		container_of(context, struct iso_context, context);
2516 	int i;
2517 	struct descriptor *pd;
2518 
2519 	for (pd = d; pd <= last; pd++)
2520 		if (pd->transfer_status)
2521 			break;
2522 	if (pd > last)
2523 		/* Descriptor(s) not done yet, stop iteration */
2524 		return 0;
2525 
2526 	i = ctx->header_length;
2527 	if (i + 4 < PAGE_SIZE) {
2528 		/* Present this value as big-endian to match the receive code */
2529 		*(__be32 *)(ctx->header + i) = cpu_to_be32(
2530 				((u32)le16_to_cpu(pd->transfer_status) << 16) |
2531 				le16_to_cpu(pd->res_count));
2532 		ctx->header_length += 4;
2533 	}
2534 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
2535 		ctx->base.callback.sc(&ctx->base, le16_to_cpu(last->res_count),
2536 				      ctx->header_length, ctx->header,
2537 				      ctx->base.callback_data);
2538 		ctx->header_length = 0;
2539 	}
2540 	return 1;
2541 }
2542 
2543 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2544 {
2545 	u32 hi = channels >> 32, lo = channels;
2546 
2547 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2548 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2549 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2550 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2551 	mmiowb();
2552 	ohci->mc_channels = channels;
2553 }
2554 
2555 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2556 				int type, int channel, size_t header_size)
2557 {
2558 	struct fw_ohci *ohci = fw_ohci(card);
2559 	struct iso_context *uninitialized_var(ctx);
2560 	descriptor_callback_t uninitialized_var(callback);
2561 	u64 *uninitialized_var(channels);
2562 	u32 *uninitialized_var(mask), uninitialized_var(regs);
2563 	unsigned long flags;
2564 	int index, ret = -EBUSY;
2565 
2566 	spin_lock_irqsave(&ohci->lock, flags);
2567 
2568 	switch (type) {
2569 	case FW_ISO_CONTEXT_TRANSMIT:
2570 		mask     = &ohci->it_context_mask;
2571 		callback = handle_it_packet;
2572 		index    = ffs(*mask) - 1;
2573 		if (index >= 0) {
2574 			*mask &= ~(1 << index);
2575 			regs = OHCI1394_IsoXmitContextBase(index);
2576 			ctx  = &ohci->it_context_list[index];
2577 		}
2578 		break;
2579 
2580 	case FW_ISO_CONTEXT_RECEIVE:
2581 		channels = &ohci->ir_context_channels;
2582 		mask     = &ohci->ir_context_mask;
2583 		callback = handle_ir_packet_per_buffer;
2584 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2585 		if (index >= 0) {
2586 			*channels &= ~(1ULL << channel);
2587 			*mask     &= ~(1 << index);
2588 			regs = OHCI1394_IsoRcvContextBase(index);
2589 			ctx  = &ohci->ir_context_list[index];
2590 		}
2591 		break;
2592 
2593 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2594 		mask     = &ohci->ir_context_mask;
2595 		callback = handle_ir_buffer_fill;
2596 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2597 		if (index >= 0) {
2598 			ohci->mc_allocated = true;
2599 			*mask &= ~(1 << index);
2600 			regs = OHCI1394_IsoRcvContextBase(index);
2601 			ctx  = &ohci->ir_context_list[index];
2602 		}
2603 		break;
2604 
2605 	default:
2606 		index = -1;
2607 		ret = -ENOSYS;
2608 	}
2609 
2610 	spin_unlock_irqrestore(&ohci->lock, flags);
2611 
2612 	if (index < 0)
2613 		return ERR_PTR(ret);
2614 
2615 	memset(ctx, 0, sizeof(*ctx));
2616 	ctx->header_length = 0;
2617 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
2618 	if (ctx->header == NULL) {
2619 		ret = -ENOMEM;
2620 		goto out;
2621 	}
2622 	ret = context_init(&ctx->context, ohci, regs, callback);
2623 	if (ret < 0)
2624 		goto out_with_header;
2625 
2626 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL)
2627 		set_multichannel_mask(ohci, 0);
2628 
2629 	return &ctx->base;
2630 
2631  out_with_header:
2632 	free_page((unsigned long)ctx->header);
2633  out:
2634 	spin_lock_irqsave(&ohci->lock, flags);
2635 
2636 	switch (type) {
2637 	case FW_ISO_CONTEXT_RECEIVE:
2638 		*channels |= 1ULL << channel;
2639 		break;
2640 
2641 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2642 		ohci->mc_allocated = false;
2643 		break;
2644 	}
2645 	*mask |= 1 << index;
2646 
2647 	spin_unlock_irqrestore(&ohci->lock, flags);
2648 
2649 	return ERR_PTR(ret);
2650 }
2651 
2652 static int ohci_start_iso(struct fw_iso_context *base,
2653 			  s32 cycle, u32 sync, u32 tags)
2654 {
2655 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2656 	struct fw_ohci *ohci = ctx->context.ohci;
2657 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
2658 	int index;
2659 
2660 	switch (ctx->base.type) {
2661 	case FW_ISO_CONTEXT_TRANSMIT:
2662 		index = ctx - ohci->it_context_list;
2663 		match = 0;
2664 		if (cycle >= 0)
2665 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
2666 				(cycle & 0x7fff) << 16;
2667 
2668 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
2669 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
2670 		context_run(&ctx->context, match);
2671 		break;
2672 
2673 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2674 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
2675 		/* fall through */
2676 	case FW_ISO_CONTEXT_RECEIVE:
2677 		index = ctx - ohci->ir_context_list;
2678 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
2679 		if (cycle >= 0) {
2680 			match |= (cycle & 0x07fff) << 12;
2681 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
2682 		}
2683 
2684 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
2685 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
2686 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
2687 		context_run(&ctx->context, control);
2688 
2689 		ctx->sync = sync;
2690 		ctx->tags = tags;
2691 
2692 		break;
2693 	}
2694 
2695 	return 0;
2696 }
2697 
2698 static int ohci_stop_iso(struct fw_iso_context *base)
2699 {
2700 	struct fw_ohci *ohci = fw_ohci(base->card);
2701 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2702 	int index;
2703 
2704 	switch (ctx->base.type) {
2705 	case FW_ISO_CONTEXT_TRANSMIT:
2706 		index = ctx - ohci->it_context_list;
2707 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
2708 		break;
2709 
2710 	case FW_ISO_CONTEXT_RECEIVE:
2711 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2712 		index = ctx - ohci->ir_context_list;
2713 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
2714 		break;
2715 	}
2716 	flush_writes(ohci);
2717 	context_stop(&ctx->context);
2718 
2719 	return 0;
2720 }
2721 
2722 static void ohci_free_iso_context(struct fw_iso_context *base)
2723 {
2724 	struct fw_ohci *ohci = fw_ohci(base->card);
2725 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2726 	unsigned long flags;
2727 	int index;
2728 
2729 	ohci_stop_iso(base);
2730 	context_release(&ctx->context);
2731 	free_page((unsigned long)ctx->header);
2732 
2733 	spin_lock_irqsave(&ohci->lock, flags);
2734 
2735 	switch (base->type) {
2736 	case FW_ISO_CONTEXT_TRANSMIT:
2737 		index = ctx - ohci->it_context_list;
2738 		ohci->it_context_mask |= 1 << index;
2739 		break;
2740 
2741 	case FW_ISO_CONTEXT_RECEIVE:
2742 		index = ctx - ohci->ir_context_list;
2743 		ohci->ir_context_mask |= 1 << index;
2744 		ohci->ir_context_channels |= 1ULL << base->channel;
2745 		break;
2746 
2747 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2748 		index = ctx - ohci->ir_context_list;
2749 		ohci->ir_context_mask |= 1 << index;
2750 		ohci->ir_context_channels |= ohci->mc_channels;
2751 		ohci->mc_channels = 0;
2752 		ohci->mc_allocated = false;
2753 		break;
2754 	}
2755 
2756 	spin_unlock_irqrestore(&ohci->lock, flags);
2757 }
2758 
2759 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
2760 {
2761 	struct fw_ohci *ohci = fw_ohci(base->card);
2762 	unsigned long flags;
2763 	int ret;
2764 
2765 	switch (base->type) {
2766 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2767 
2768 		spin_lock_irqsave(&ohci->lock, flags);
2769 
2770 		/* Don't allow multichannel to grab other contexts' channels. */
2771 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
2772 			*channels = ohci->ir_context_channels;
2773 			ret = -EBUSY;
2774 		} else {
2775 			set_multichannel_mask(ohci, *channels);
2776 			ret = 0;
2777 		}
2778 
2779 		spin_unlock_irqrestore(&ohci->lock, flags);
2780 
2781 		break;
2782 	default:
2783 		ret = -EINVAL;
2784 	}
2785 
2786 	return ret;
2787 }
2788 
2789 #ifdef CONFIG_PM
2790 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
2791 {
2792 	int i;
2793 	struct iso_context *ctx;
2794 
2795 	for (i = 0 ; i < ohci->n_ir ; i++) {
2796 		ctx = &ohci->ir_context_list[i];
2797 		if (ctx->context.running)
2798 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
2799 	}
2800 
2801 	for (i = 0 ; i < ohci->n_it ; i++) {
2802 		ctx = &ohci->it_context_list[i];
2803 		if (ctx->context.running)
2804 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
2805 	}
2806 }
2807 #endif
2808 
2809 static int queue_iso_transmit(struct iso_context *ctx,
2810 			      struct fw_iso_packet *packet,
2811 			      struct fw_iso_buffer *buffer,
2812 			      unsigned long payload)
2813 {
2814 	struct descriptor *d, *last, *pd;
2815 	struct fw_iso_packet *p;
2816 	__le32 *header;
2817 	dma_addr_t d_bus, page_bus;
2818 	u32 z, header_z, payload_z, irq;
2819 	u32 payload_index, payload_end_index, next_page_index;
2820 	int page, end_page, i, length, offset;
2821 
2822 	p = packet;
2823 	payload_index = payload;
2824 
2825 	if (p->skip)
2826 		z = 1;
2827 	else
2828 		z = 2;
2829 	if (p->header_length > 0)
2830 		z++;
2831 
2832 	/* Determine the first page the payload isn't contained in. */
2833 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
2834 	if (p->payload_length > 0)
2835 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
2836 	else
2837 		payload_z = 0;
2838 
2839 	z += payload_z;
2840 
2841 	/* Get header size in number of descriptors. */
2842 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
2843 
2844 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
2845 	if (d == NULL)
2846 		return -ENOMEM;
2847 
2848 	if (!p->skip) {
2849 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
2850 		d[0].req_count = cpu_to_le16(8);
2851 		/*
2852 		 * Link the skip address to this descriptor itself.  This causes
2853 		 * a context to skip a cycle whenever lost cycles or FIFO
2854 		 * overruns occur, without dropping the data.  The application
2855 		 * should then decide whether this is an error condition or not.
2856 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
2857 		 */
2858 		d[0].branch_address = cpu_to_le32(d_bus | z);
2859 
2860 		header = (__le32 *) &d[1];
2861 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
2862 					IT_HEADER_TAG(p->tag) |
2863 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
2864 					IT_HEADER_CHANNEL(ctx->base.channel) |
2865 					IT_HEADER_SPEED(ctx->base.speed));
2866 		header[1] =
2867 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
2868 							  p->payload_length));
2869 	}
2870 
2871 	if (p->header_length > 0) {
2872 		d[2].req_count    = cpu_to_le16(p->header_length);
2873 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
2874 		memcpy(&d[z], p->header, p->header_length);
2875 	}
2876 
2877 	pd = d + z - payload_z;
2878 	payload_end_index = payload_index + p->payload_length;
2879 	for (i = 0; i < payload_z; i++) {
2880 		page               = payload_index >> PAGE_SHIFT;
2881 		offset             = payload_index & ~PAGE_MASK;
2882 		next_page_index    = (page + 1) << PAGE_SHIFT;
2883 		length             =
2884 			min(next_page_index, payload_end_index) - payload_index;
2885 		pd[i].req_count    = cpu_to_le16(length);
2886 
2887 		page_bus = page_private(buffer->pages[page]);
2888 		pd[i].data_address = cpu_to_le32(page_bus + offset);
2889 
2890 		payload_index += length;
2891 	}
2892 
2893 	if (p->interrupt)
2894 		irq = DESCRIPTOR_IRQ_ALWAYS;
2895 	else
2896 		irq = DESCRIPTOR_NO_IRQ;
2897 
2898 	last = z == 2 ? d : d + z - 1;
2899 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
2900 				     DESCRIPTOR_STATUS |
2901 				     DESCRIPTOR_BRANCH_ALWAYS |
2902 				     irq);
2903 
2904 	context_append(&ctx->context, d, z, header_z);
2905 
2906 	return 0;
2907 }
2908 
2909 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
2910 				       struct fw_iso_packet *packet,
2911 				       struct fw_iso_buffer *buffer,
2912 				       unsigned long payload)
2913 {
2914 	struct descriptor *d, *pd;
2915 	dma_addr_t d_bus, page_bus;
2916 	u32 z, header_z, rest;
2917 	int i, j, length;
2918 	int page, offset, packet_count, header_size, payload_per_buffer;
2919 
2920 	/*
2921 	 * The OHCI controller puts the isochronous header and trailer in the
2922 	 * buffer, so we need at least 8 bytes.
2923 	 */
2924 	packet_count = packet->header_length / ctx->base.header_size;
2925 	header_size  = max(ctx->base.header_size, (size_t)8);
2926 
2927 	/* Get header size in number of descriptors. */
2928 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
2929 	page     = payload >> PAGE_SHIFT;
2930 	offset   = payload & ~PAGE_MASK;
2931 	payload_per_buffer = packet->payload_length / packet_count;
2932 
2933 	for (i = 0; i < packet_count; i++) {
2934 		/* d points to the header descriptor */
2935 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
2936 		d = context_get_descriptors(&ctx->context,
2937 				z + header_z, &d_bus);
2938 		if (d == NULL)
2939 			return -ENOMEM;
2940 
2941 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
2942 					      DESCRIPTOR_INPUT_MORE);
2943 		if (packet->skip && i == 0)
2944 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
2945 		d->req_count    = cpu_to_le16(header_size);
2946 		d->res_count    = d->req_count;
2947 		d->transfer_status = 0;
2948 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
2949 
2950 		rest = payload_per_buffer;
2951 		pd = d;
2952 		for (j = 1; j < z; j++) {
2953 			pd++;
2954 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
2955 						  DESCRIPTOR_INPUT_MORE);
2956 
2957 			if (offset + rest < PAGE_SIZE)
2958 				length = rest;
2959 			else
2960 				length = PAGE_SIZE - offset;
2961 			pd->req_count = cpu_to_le16(length);
2962 			pd->res_count = pd->req_count;
2963 			pd->transfer_status = 0;
2964 
2965 			page_bus = page_private(buffer->pages[page]);
2966 			pd->data_address = cpu_to_le32(page_bus + offset);
2967 
2968 			offset = (offset + length) & ~PAGE_MASK;
2969 			rest -= length;
2970 			if (offset == 0)
2971 				page++;
2972 		}
2973 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
2974 					  DESCRIPTOR_INPUT_LAST |
2975 					  DESCRIPTOR_BRANCH_ALWAYS);
2976 		if (packet->interrupt && i == packet_count - 1)
2977 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
2978 
2979 		context_append(&ctx->context, d, z, header_z);
2980 	}
2981 
2982 	return 0;
2983 }
2984 
2985 static int queue_iso_buffer_fill(struct iso_context *ctx,
2986 				 struct fw_iso_packet *packet,
2987 				 struct fw_iso_buffer *buffer,
2988 				 unsigned long payload)
2989 {
2990 	struct descriptor *d;
2991 	dma_addr_t d_bus, page_bus;
2992 	int page, offset, rest, z, i, length;
2993 
2994 	page   = payload >> PAGE_SHIFT;
2995 	offset = payload & ~PAGE_MASK;
2996 	rest   = packet->payload_length;
2997 
2998 	/* We need one descriptor for each page in the buffer. */
2999 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3000 
3001 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3002 		return -EFAULT;
3003 
3004 	for (i = 0; i < z; i++) {
3005 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3006 		if (d == NULL)
3007 			return -ENOMEM;
3008 
3009 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3010 					 DESCRIPTOR_BRANCH_ALWAYS);
3011 		if (packet->skip && i == 0)
3012 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3013 		if (packet->interrupt && i == z - 1)
3014 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3015 
3016 		if (offset + rest < PAGE_SIZE)
3017 			length = rest;
3018 		else
3019 			length = PAGE_SIZE - offset;
3020 		d->req_count = cpu_to_le16(length);
3021 		d->res_count = d->req_count;
3022 		d->transfer_status = 0;
3023 
3024 		page_bus = page_private(buffer->pages[page]);
3025 		d->data_address = cpu_to_le32(page_bus + offset);
3026 
3027 		rest -= length;
3028 		offset = 0;
3029 		page++;
3030 
3031 		context_append(&ctx->context, d, 1, 0);
3032 	}
3033 
3034 	return 0;
3035 }
3036 
3037 static int ohci_queue_iso(struct fw_iso_context *base,
3038 			  struct fw_iso_packet *packet,
3039 			  struct fw_iso_buffer *buffer,
3040 			  unsigned long payload)
3041 {
3042 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3043 	unsigned long flags;
3044 	int ret = -ENOSYS;
3045 
3046 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3047 	switch (base->type) {
3048 	case FW_ISO_CONTEXT_TRANSMIT:
3049 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3050 		break;
3051 	case FW_ISO_CONTEXT_RECEIVE:
3052 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3053 		break;
3054 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3055 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3056 		break;
3057 	}
3058 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3059 
3060 	return ret;
3061 }
3062 
3063 static const struct fw_card_driver ohci_driver = {
3064 	.enable			= ohci_enable,
3065 	.read_phy_reg		= ohci_read_phy_reg,
3066 	.update_phy_reg		= ohci_update_phy_reg,
3067 	.set_config_rom		= ohci_set_config_rom,
3068 	.send_request		= ohci_send_request,
3069 	.send_response		= ohci_send_response,
3070 	.cancel_packet		= ohci_cancel_packet,
3071 	.enable_phys_dma	= ohci_enable_phys_dma,
3072 	.read_csr		= ohci_read_csr,
3073 	.write_csr		= ohci_write_csr,
3074 
3075 	.allocate_iso_context	= ohci_allocate_iso_context,
3076 	.free_iso_context	= ohci_free_iso_context,
3077 	.set_iso_channels	= ohci_set_iso_channels,
3078 	.queue_iso		= ohci_queue_iso,
3079 	.start_iso		= ohci_start_iso,
3080 	.stop_iso		= ohci_stop_iso,
3081 };
3082 
3083 #ifdef CONFIG_PPC_PMAC
3084 static void pmac_ohci_on(struct pci_dev *dev)
3085 {
3086 	if (machine_is(powermac)) {
3087 		struct device_node *ofn = pci_device_to_OF_node(dev);
3088 
3089 		if (ofn) {
3090 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3091 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3092 		}
3093 	}
3094 }
3095 
3096 static void pmac_ohci_off(struct pci_dev *dev)
3097 {
3098 	if (machine_is(powermac)) {
3099 		struct device_node *ofn = pci_device_to_OF_node(dev);
3100 
3101 		if (ofn) {
3102 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3103 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3104 		}
3105 	}
3106 }
3107 #else
3108 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3109 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3110 #endif /* CONFIG_PPC_PMAC */
3111 
3112 static int __devinit pci_probe(struct pci_dev *dev,
3113 			       const struct pci_device_id *ent)
3114 {
3115 	struct fw_ohci *ohci;
3116 	u32 bus_options, max_receive, link_speed, version;
3117 	u64 guid;
3118 	int i, err;
3119 	size_t size;
3120 
3121 	ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3122 	if (ohci == NULL) {
3123 		err = -ENOMEM;
3124 		goto fail;
3125 	}
3126 
3127 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3128 
3129 	pmac_ohci_on(dev);
3130 
3131 	err = pci_enable_device(dev);
3132 	if (err) {
3133 		fw_error("Failed to enable OHCI hardware\n");
3134 		goto fail_free;
3135 	}
3136 
3137 	pci_set_master(dev);
3138 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3139 	pci_set_drvdata(dev, ohci);
3140 
3141 	spin_lock_init(&ohci->lock);
3142 	mutex_init(&ohci->phy_reg_mutex);
3143 
3144 	tasklet_init(&ohci->bus_reset_tasklet,
3145 		     bus_reset_tasklet, (unsigned long)ohci);
3146 
3147 	err = pci_request_region(dev, 0, ohci_driver_name);
3148 	if (err) {
3149 		fw_error("MMIO resource unavailable\n");
3150 		goto fail_disable;
3151 	}
3152 
3153 	ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3154 	if (ohci->registers == NULL) {
3155 		fw_error("Failed to remap registers\n");
3156 		err = -ENXIO;
3157 		goto fail_iomem;
3158 	}
3159 
3160 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3161 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3162 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3163 		     ohci_quirks[i].device == dev->device) &&
3164 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3165 		     ohci_quirks[i].revision >= dev->revision)) {
3166 			ohci->quirks = ohci_quirks[i].flags;
3167 			break;
3168 		}
3169 	if (param_quirks)
3170 		ohci->quirks = param_quirks;
3171 
3172 	/*
3173 	 * Because dma_alloc_coherent() allocates at least one page,
3174 	 * we save space by using a common buffer for the AR request/
3175 	 * response descriptors and the self IDs buffer.
3176 	 */
3177 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3178 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3179 	ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3180 					       PAGE_SIZE,
3181 					       &ohci->misc_buffer_bus,
3182 					       GFP_KERNEL);
3183 	if (!ohci->misc_buffer) {
3184 		err = -ENOMEM;
3185 		goto fail_iounmap;
3186 	}
3187 
3188 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3189 			      OHCI1394_AsReqRcvContextControlSet);
3190 	if (err < 0)
3191 		goto fail_misc_buf;
3192 
3193 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3194 			      OHCI1394_AsRspRcvContextControlSet);
3195 	if (err < 0)
3196 		goto fail_arreq_ctx;
3197 
3198 	err = context_init(&ohci->at_request_ctx, ohci,
3199 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3200 	if (err < 0)
3201 		goto fail_arrsp_ctx;
3202 
3203 	err = context_init(&ohci->at_response_ctx, ohci,
3204 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3205 	if (err < 0)
3206 		goto fail_atreq_ctx;
3207 
3208 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3209 	ohci->ir_context_channels = ~0ULL;
3210 	ohci->ir_context_mask = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3211 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3212 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3213 	size = sizeof(struct iso_context) * ohci->n_ir;
3214 	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3215 
3216 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3217 	ohci->it_context_mask = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3218 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3219 	ohci->n_it = hweight32(ohci->it_context_mask);
3220 	size = sizeof(struct iso_context) * ohci->n_it;
3221 	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3222 
3223 	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3224 		err = -ENOMEM;
3225 		goto fail_contexts;
3226 	}
3227 
3228 	ohci->self_id_cpu = ohci->misc_buffer     + PAGE_SIZE/2;
3229 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3230 
3231 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3232 	max_receive = (bus_options >> 12) & 0xf;
3233 	link_speed = bus_options & 0x7;
3234 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3235 		reg_read(ohci, OHCI1394_GUIDLo);
3236 
3237 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3238 	if (err)
3239 		goto fail_contexts;
3240 
3241 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3242 	fw_notify("Added fw-ohci device %s, OHCI v%x.%x, "
3243 		  "%d IR + %d IT contexts, quirks 0x%x\n",
3244 		  dev_name(&dev->dev), version >> 16, version & 0xff,
3245 		  ohci->n_ir, ohci->n_it, ohci->quirks);
3246 
3247 	return 0;
3248 
3249  fail_contexts:
3250 	kfree(ohci->ir_context_list);
3251 	kfree(ohci->it_context_list);
3252 	context_release(&ohci->at_response_ctx);
3253  fail_atreq_ctx:
3254 	context_release(&ohci->at_request_ctx);
3255  fail_arrsp_ctx:
3256 	ar_context_release(&ohci->ar_response_ctx);
3257  fail_arreq_ctx:
3258 	ar_context_release(&ohci->ar_request_ctx);
3259  fail_misc_buf:
3260 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3261 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3262  fail_iounmap:
3263 	pci_iounmap(dev, ohci->registers);
3264  fail_iomem:
3265 	pci_release_region(dev, 0);
3266  fail_disable:
3267 	pci_disable_device(dev);
3268  fail_free:
3269 	kfree(&ohci->card);
3270 	pmac_ohci_off(dev);
3271  fail:
3272 	if (err == -ENOMEM)
3273 		fw_error("Out of memory\n");
3274 
3275 	return err;
3276 }
3277 
3278 static void pci_remove(struct pci_dev *dev)
3279 {
3280 	struct fw_ohci *ohci;
3281 
3282 	ohci = pci_get_drvdata(dev);
3283 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3284 	flush_writes(ohci);
3285 	fw_core_remove_card(&ohci->card);
3286 
3287 	/*
3288 	 * FIXME: Fail all pending packets here, now that the upper
3289 	 * layers can't queue any more.
3290 	 */
3291 
3292 	software_reset(ohci);
3293 	free_irq(dev->irq, ohci);
3294 
3295 	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3296 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3297 				  ohci->next_config_rom, ohci->next_config_rom_bus);
3298 	if (ohci->config_rom)
3299 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3300 				  ohci->config_rom, ohci->config_rom_bus);
3301 	ar_context_release(&ohci->ar_request_ctx);
3302 	ar_context_release(&ohci->ar_response_ctx);
3303 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3304 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3305 	context_release(&ohci->at_request_ctx);
3306 	context_release(&ohci->at_response_ctx);
3307 	kfree(ohci->it_context_list);
3308 	kfree(ohci->ir_context_list);
3309 	pci_disable_msi(dev);
3310 	pci_iounmap(dev, ohci->registers);
3311 	pci_release_region(dev, 0);
3312 	pci_disable_device(dev);
3313 	kfree(&ohci->card);
3314 	pmac_ohci_off(dev);
3315 
3316 	fw_notify("Removed fw-ohci device.\n");
3317 }
3318 
3319 #ifdef CONFIG_PM
3320 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3321 {
3322 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3323 	int err;
3324 
3325 	software_reset(ohci);
3326 	free_irq(dev->irq, ohci);
3327 	pci_disable_msi(dev);
3328 	err = pci_save_state(dev);
3329 	if (err) {
3330 		fw_error("pci_save_state failed\n");
3331 		return err;
3332 	}
3333 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3334 	if (err)
3335 		fw_error("pci_set_power_state failed with %d\n", err);
3336 	pmac_ohci_off(dev);
3337 
3338 	return 0;
3339 }
3340 
3341 static int pci_resume(struct pci_dev *dev)
3342 {
3343 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3344 	int err;
3345 
3346 	pmac_ohci_on(dev);
3347 	pci_set_power_state(dev, PCI_D0);
3348 	pci_restore_state(dev);
3349 	err = pci_enable_device(dev);
3350 	if (err) {
3351 		fw_error("pci_enable_device failed\n");
3352 		return err;
3353 	}
3354 
3355 	/* Some systems don't setup GUID register on resume from ram  */
3356 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3357 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3358 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3359 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3360 	}
3361 
3362 	err = ohci_enable(&ohci->card, NULL, 0);
3363 	if (err)
3364 		return err;
3365 
3366 	ohci_resume_iso_dma(ohci);
3367 
3368 	return 0;
3369 }
3370 #endif
3371 
3372 static const struct pci_device_id pci_table[] = {
3373 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3374 	{ }
3375 };
3376 
3377 MODULE_DEVICE_TABLE(pci, pci_table);
3378 
3379 static struct pci_driver fw_ohci_pci_driver = {
3380 	.name		= ohci_driver_name,
3381 	.id_table	= pci_table,
3382 	.probe		= pci_probe,
3383 	.remove		= pci_remove,
3384 #ifdef CONFIG_PM
3385 	.resume		= pci_resume,
3386 	.suspend	= pci_suspend,
3387 #endif
3388 };
3389 
3390 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3391 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3392 MODULE_LICENSE("GPL");
3393 
3394 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3395 #ifndef CONFIG_IEEE1394_OHCI1394_MODULE
3396 MODULE_ALIAS("ohci1394");
3397 #endif
3398 
3399 static int __init fw_ohci_init(void)
3400 {
3401 	return pci_register_driver(&fw_ohci_pci_driver);
3402 }
3403 
3404 static void __exit fw_ohci_cleanup(void)
3405 {
3406 	pci_unregister_driver(&fw_ohci_pci_driver);
3407 }
3408 
3409 module_init(fw_ohci_init);
3410 module_exit(fw_ohci_cleanup);
3411