xref: /openbmc/linux/drivers/firewire/ohci.c (revision 565d76cb)
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_support;
212 	u32 it_context_mask;     /* unoccupied IT contexts */
213 	struct iso_context *it_context_list;
214 	u64 ir_context_channels; /* unoccupied channels */
215 	u32 ir_context_support;
216 	u32 ir_context_mask;     /* unoccupied IR contexts */
217 	struct iso_context *ir_context_list;
218 	u64 mc_channels; /* channels in use by the multichannel IR context */
219 	bool mc_allocated;
220 
221 	__be32    *config_rom;
222 	dma_addr_t config_rom_bus;
223 	__be32    *next_config_rom;
224 	dma_addr_t next_config_rom_bus;
225 	__be32     next_header;
226 
227 	__le32    *self_id_cpu;
228 	dma_addr_t self_id_bus;
229 	struct tasklet_struct bus_reset_tasklet;
230 
231 	u32 self_id_buffer[512];
232 };
233 
234 static inline struct fw_ohci *fw_ohci(struct fw_card *card)
235 {
236 	return container_of(card, struct fw_ohci, card);
237 }
238 
239 #define IT_CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
240 #define IR_CONTEXT_BUFFER_FILL		0x80000000
241 #define IR_CONTEXT_ISOCH_HEADER		0x40000000
242 #define IR_CONTEXT_CYCLE_MATCH_ENABLE	0x20000000
243 #define IR_CONTEXT_MULTI_CHANNEL_MODE	0x10000000
244 #define IR_CONTEXT_DUAL_BUFFER_MODE	0x08000000
245 
246 #define CONTEXT_RUN	0x8000
247 #define CONTEXT_WAKE	0x1000
248 #define CONTEXT_DEAD	0x0800
249 #define CONTEXT_ACTIVE	0x0400
250 
251 #define OHCI1394_MAX_AT_REQ_RETRIES	0xf
252 #define OHCI1394_MAX_AT_RESP_RETRIES	0x2
253 #define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
254 
255 #define OHCI1394_REGISTER_SIZE		0x800
256 #define OHCI_LOOP_COUNT			500
257 #define OHCI1394_PCI_HCI_Control	0x40
258 #define SELF_ID_BUF_SIZE		0x800
259 #define OHCI_TCODE_PHY_PACKET		0x0e
260 #define OHCI_VERSION_1_1		0x010010
261 
262 static char ohci_driver_name[] = KBUILD_MODNAME;
263 
264 #define PCI_DEVICE_ID_AGERE_FW643	0x5901
265 #define PCI_DEVICE_ID_JMICRON_JMB38X_FW	0x2380
266 #define PCI_DEVICE_ID_TI_TSB12LV22	0x8009
267 
268 #define QUIRK_CYCLE_TIMER		1
269 #define QUIRK_RESET_PACKET		2
270 #define QUIRK_BE_HEADERS		4
271 #define QUIRK_NO_1394A			8
272 #define QUIRK_NO_MSI			16
273 
274 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
275 static const struct {
276 	unsigned short vendor, device, revision, flags;
277 } ohci_quirks[] = {
278 	{PCI_VENDOR_ID_AL, PCI_ANY_ID, PCI_ANY_ID,
279 		QUIRK_CYCLE_TIMER},
280 
281 	{PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_UNI_N_FW, PCI_ANY_ID,
282 		QUIRK_BE_HEADERS},
283 
284 	{PCI_VENDOR_ID_ATT, PCI_DEVICE_ID_AGERE_FW643, 6,
285 		QUIRK_NO_MSI},
286 
287 	{PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB38X_FW, PCI_ANY_ID,
288 		QUIRK_NO_MSI},
289 
290 	{PCI_VENDOR_ID_NEC, PCI_ANY_ID, PCI_ANY_ID,
291 		QUIRK_CYCLE_TIMER},
292 
293 	{PCI_VENDOR_ID_RICOH, PCI_ANY_ID, PCI_ANY_ID,
294 		QUIRK_CYCLE_TIMER},
295 
296 	{PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_TSB12LV22, PCI_ANY_ID,
297 		QUIRK_CYCLE_TIMER | QUIRK_RESET_PACKET | QUIRK_NO_1394A},
298 
299 	{PCI_VENDOR_ID_TI, PCI_ANY_ID, PCI_ANY_ID,
300 		QUIRK_RESET_PACKET},
301 
302 	{PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_ANY_ID,
303 		QUIRK_CYCLE_TIMER | QUIRK_NO_MSI},
304 };
305 
306 /* This overrides anything that was found in ohci_quirks[]. */
307 static int param_quirks;
308 module_param_named(quirks, param_quirks, int, 0644);
309 MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
310 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
311 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
312 	", AR/selfID endianess = "	__stringify(QUIRK_BE_HEADERS)
313 	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
314 	", disable MSI = "		__stringify(QUIRK_NO_MSI)
315 	")");
316 
317 #define OHCI_PARAM_DEBUG_AT_AR		1
318 #define OHCI_PARAM_DEBUG_SELFIDS	2
319 #define OHCI_PARAM_DEBUG_IRQS		4
320 #define OHCI_PARAM_DEBUG_BUSRESETS	8 /* only effective before chip init */
321 
322 #ifdef CONFIG_FIREWIRE_OHCI_DEBUG
323 
324 static int param_debug;
325 module_param_named(debug, param_debug, int, 0644);
326 MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
327 	", AT/AR events = "	__stringify(OHCI_PARAM_DEBUG_AT_AR)
328 	", self-IDs = "		__stringify(OHCI_PARAM_DEBUG_SELFIDS)
329 	", IRQs = "		__stringify(OHCI_PARAM_DEBUG_IRQS)
330 	", busReset events = "	__stringify(OHCI_PARAM_DEBUG_BUSRESETS)
331 	", or a combination, or all = -1)");
332 
333 static void log_irqs(u32 evt)
334 {
335 	if (likely(!(param_debug &
336 			(OHCI_PARAM_DEBUG_IRQS | OHCI_PARAM_DEBUG_BUSRESETS))))
337 		return;
338 
339 	if (!(param_debug & OHCI_PARAM_DEBUG_IRQS) &&
340 	    !(evt & OHCI1394_busReset))
341 		return;
342 
343 	fw_notify("IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
344 	    evt & OHCI1394_selfIDComplete	? " selfID"		: "",
345 	    evt & OHCI1394_RQPkt		? " AR_req"		: "",
346 	    evt & OHCI1394_RSPkt		? " AR_resp"		: "",
347 	    evt & OHCI1394_reqTxComplete	? " AT_req"		: "",
348 	    evt & OHCI1394_respTxComplete	? " AT_resp"		: "",
349 	    evt & OHCI1394_isochRx		? " IR"			: "",
350 	    evt & OHCI1394_isochTx		? " IT"			: "",
351 	    evt & OHCI1394_postedWriteErr	? " postedWriteErr"	: "",
352 	    evt & OHCI1394_cycleTooLong		? " cycleTooLong"	: "",
353 	    evt & OHCI1394_cycle64Seconds	? " cycle64Seconds"	: "",
354 	    evt & OHCI1394_cycleInconsistent	? " cycleInconsistent"	: "",
355 	    evt & OHCI1394_regAccessFail	? " regAccessFail"	: "",
356 	    evt & OHCI1394_unrecoverableError	? " unrecoverableError"	: "",
357 	    evt & OHCI1394_busReset		? " busReset"		: "",
358 	    evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
359 		    OHCI1394_RSPkt | OHCI1394_reqTxComplete |
360 		    OHCI1394_respTxComplete | OHCI1394_isochRx |
361 		    OHCI1394_isochTx | OHCI1394_postedWriteErr |
362 		    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
363 		    OHCI1394_cycleInconsistent |
364 		    OHCI1394_regAccessFail | OHCI1394_busReset)
365 						? " ?"			: "");
366 }
367 
368 static const char *speed[] = {
369 	[0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
370 };
371 static const char *power[] = {
372 	[0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
373 	[4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
374 };
375 static const char port[] = { '.', '-', 'p', 'c', };
376 
377 static char _p(u32 *s, int shift)
378 {
379 	return port[*s >> shift & 3];
380 }
381 
382 static void log_selfids(int node_id, int generation, int self_id_count, u32 *s)
383 {
384 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
385 		return;
386 
387 	fw_notify("%d selfIDs, generation %d, local node ID %04x\n",
388 		  self_id_count, generation, node_id);
389 
390 	for (; self_id_count--; ++s)
391 		if ((*s & 1 << 23) == 0)
392 			fw_notify("selfID 0: %08x, phy %d [%c%c%c] "
393 			    "%s gc=%d %s %s%s%s\n",
394 			    *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
395 			    speed[*s >> 14 & 3], *s >> 16 & 63,
396 			    power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
397 			    *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
398 		else
399 			fw_notify("selfID n: %08x, phy %d [%c%c%c%c%c%c%c%c]\n",
400 			    *s, *s >> 24 & 63,
401 			    _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
402 			    _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
403 }
404 
405 static const char *evts[] = {
406 	[0x00] = "evt_no_status",	[0x01] = "-reserved-",
407 	[0x02] = "evt_long_packet",	[0x03] = "evt_missing_ack",
408 	[0x04] = "evt_underrun",	[0x05] = "evt_overrun",
409 	[0x06] = "evt_descriptor_read",	[0x07] = "evt_data_read",
410 	[0x08] = "evt_data_write",	[0x09] = "evt_bus_reset",
411 	[0x0a] = "evt_timeout",		[0x0b] = "evt_tcode_err",
412 	[0x0c] = "-reserved-",		[0x0d] = "-reserved-",
413 	[0x0e] = "evt_unknown",		[0x0f] = "evt_flushed",
414 	[0x10] = "-reserved-",		[0x11] = "ack_complete",
415 	[0x12] = "ack_pending ",	[0x13] = "-reserved-",
416 	[0x14] = "ack_busy_X",		[0x15] = "ack_busy_A",
417 	[0x16] = "ack_busy_B",		[0x17] = "-reserved-",
418 	[0x18] = "-reserved-",		[0x19] = "-reserved-",
419 	[0x1a] = "-reserved-",		[0x1b] = "ack_tardy",
420 	[0x1c] = "-reserved-",		[0x1d] = "ack_data_error",
421 	[0x1e] = "ack_type_error",	[0x1f] = "-reserved-",
422 	[0x20] = "pending/cancelled",
423 };
424 static const char *tcodes[] = {
425 	[0x0] = "QW req",		[0x1] = "BW req",
426 	[0x2] = "W resp",		[0x3] = "-reserved-",
427 	[0x4] = "QR req",		[0x5] = "BR req",
428 	[0x6] = "QR resp",		[0x7] = "BR resp",
429 	[0x8] = "cycle start",		[0x9] = "Lk req",
430 	[0xa] = "async stream packet",	[0xb] = "Lk resp",
431 	[0xc] = "-reserved-",		[0xd] = "-reserved-",
432 	[0xe] = "link internal",	[0xf] = "-reserved-",
433 };
434 
435 static void log_ar_at_event(char dir, int speed, u32 *header, int evt)
436 {
437 	int tcode = header[0] >> 4 & 0xf;
438 	char specific[12];
439 
440 	if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
441 		return;
442 
443 	if (unlikely(evt >= ARRAY_SIZE(evts)))
444 			evt = 0x1f;
445 
446 	if (evt == OHCI1394_evt_bus_reset) {
447 		fw_notify("A%c evt_bus_reset, generation %d\n",
448 		    dir, (header[2] >> 16) & 0xff);
449 		return;
450 	}
451 
452 	switch (tcode) {
453 	case 0x0: case 0x6: case 0x8:
454 		snprintf(specific, sizeof(specific), " = %08x",
455 			 be32_to_cpu((__force __be32)header[3]));
456 		break;
457 	case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
458 		snprintf(specific, sizeof(specific), " %x,%x",
459 			 header[3] >> 16, header[3] & 0xffff);
460 		break;
461 	default:
462 		specific[0] = '\0';
463 	}
464 
465 	switch (tcode) {
466 	case 0xa:
467 		fw_notify("A%c %s, %s\n", dir, evts[evt], tcodes[tcode]);
468 		break;
469 	case 0xe:
470 		fw_notify("A%c %s, PHY %08x %08x\n",
471 			  dir, evts[evt], header[1], header[2]);
472 		break;
473 	case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
474 		fw_notify("A%c spd %x tl %02x, "
475 		    "%04x -> %04x, %s, "
476 		    "%s, %04x%08x%s\n",
477 		    dir, speed, header[0] >> 10 & 0x3f,
478 		    header[1] >> 16, header[0] >> 16, evts[evt],
479 		    tcodes[tcode], header[1] & 0xffff, header[2], specific);
480 		break;
481 	default:
482 		fw_notify("A%c spd %x tl %02x, "
483 		    "%04x -> %04x, %s, "
484 		    "%s%s\n",
485 		    dir, speed, header[0] >> 10 & 0x3f,
486 		    header[1] >> 16, header[0] >> 16, evts[evt],
487 		    tcodes[tcode], specific);
488 	}
489 }
490 
491 #else
492 
493 #define param_debug 0
494 static inline void log_irqs(u32 evt) {}
495 static inline void log_selfids(int node_id, int generation, int self_id_count, u32 *s) {}
496 static inline void log_ar_at_event(char dir, int speed, u32 *header, int evt) {}
497 
498 #endif /* CONFIG_FIREWIRE_OHCI_DEBUG */
499 
500 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
501 {
502 	writel(data, ohci->registers + offset);
503 }
504 
505 static inline u32 reg_read(const struct fw_ohci *ohci, int offset)
506 {
507 	return readl(ohci->registers + offset);
508 }
509 
510 static inline void flush_writes(const struct fw_ohci *ohci)
511 {
512 	/* Do a dummy read to flush writes. */
513 	reg_read(ohci, OHCI1394_Version);
514 }
515 
516 static int read_phy_reg(struct fw_ohci *ohci, int addr)
517 {
518 	u32 val;
519 	int i;
520 
521 	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
522 	for (i = 0; i < 3 + 100; i++) {
523 		val = reg_read(ohci, OHCI1394_PhyControl);
524 		if (val & OHCI1394_PhyControl_ReadDone)
525 			return OHCI1394_PhyControl_ReadData(val);
526 
527 		/*
528 		 * Try a few times without waiting.  Sleeping is necessary
529 		 * only when the link/PHY interface is busy.
530 		 */
531 		if (i >= 3)
532 			msleep(1);
533 	}
534 	fw_error("failed to read phy reg\n");
535 
536 	return -EBUSY;
537 }
538 
539 static int write_phy_reg(const struct fw_ohci *ohci, int addr, u32 val)
540 {
541 	int i;
542 
543 	reg_write(ohci, OHCI1394_PhyControl,
544 		  OHCI1394_PhyControl_Write(addr, val));
545 	for (i = 0; i < 3 + 100; i++) {
546 		val = reg_read(ohci, OHCI1394_PhyControl);
547 		if (!(val & OHCI1394_PhyControl_WritePending))
548 			return 0;
549 
550 		if (i >= 3)
551 			msleep(1);
552 	}
553 	fw_error("failed to write phy reg\n");
554 
555 	return -EBUSY;
556 }
557 
558 static int update_phy_reg(struct fw_ohci *ohci, int addr,
559 			  int clear_bits, int set_bits)
560 {
561 	int ret = read_phy_reg(ohci, addr);
562 	if (ret < 0)
563 		return ret;
564 
565 	/*
566 	 * The interrupt status bits are cleared by writing a one bit.
567 	 * Avoid clearing them unless explicitly requested in set_bits.
568 	 */
569 	if (addr == 5)
570 		clear_bits |= PHY_INT_STATUS_BITS;
571 
572 	return write_phy_reg(ohci, addr, (ret & ~clear_bits) | set_bits);
573 }
574 
575 static int read_paged_phy_reg(struct fw_ohci *ohci, int page, int addr)
576 {
577 	int ret;
578 
579 	ret = update_phy_reg(ohci, 7, PHY_PAGE_SELECT, page << 5);
580 	if (ret < 0)
581 		return ret;
582 
583 	return read_phy_reg(ohci, addr);
584 }
585 
586 static int ohci_read_phy_reg(struct fw_card *card, int addr)
587 {
588 	struct fw_ohci *ohci = fw_ohci(card);
589 	int ret;
590 
591 	mutex_lock(&ohci->phy_reg_mutex);
592 	ret = read_phy_reg(ohci, addr);
593 	mutex_unlock(&ohci->phy_reg_mutex);
594 
595 	return ret;
596 }
597 
598 static int ohci_update_phy_reg(struct fw_card *card, int addr,
599 			       int clear_bits, int set_bits)
600 {
601 	struct fw_ohci *ohci = fw_ohci(card);
602 	int ret;
603 
604 	mutex_lock(&ohci->phy_reg_mutex);
605 	ret = update_phy_reg(ohci, addr, clear_bits, set_bits);
606 	mutex_unlock(&ohci->phy_reg_mutex);
607 
608 	return ret;
609 }
610 
611 static inline dma_addr_t ar_buffer_bus(struct ar_context *ctx, unsigned int i)
612 {
613 	return page_private(ctx->pages[i]);
614 }
615 
616 static void ar_context_link_page(struct ar_context *ctx, unsigned int index)
617 {
618 	struct descriptor *d;
619 
620 	d = &ctx->descriptors[index];
621 	d->branch_address  &= cpu_to_le32(~0xf);
622 	d->res_count       =  cpu_to_le16(PAGE_SIZE);
623 	d->transfer_status =  0;
624 
625 	wmb(); /* finish init of new descriptors before branch_address update */
626 	d = &ctx->descriptors[ctx->last_buffer_index];
627 	d->branch_address  |= cpu_to_le32(1);
628 
629 	ctx->last_buffer_index = index;
630 
631 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
632 	flush_writes(ctx->ohci);
633 }
634 
635 static void ar_context_release(struct ar_context *ctx)
636 {
637 	unsigned int i;
638 
639 	if (ctx->buffer)
640 		vm_unmap_ram(ctx->buffer, AR_BUFFERS + AR_WRAPAROUND_PAGES);
641 
642 	for (i = 0; i < AR_BUFFERS; i++)
643 		if (ctx->pages[i]) {
644 			dma_unmap_page(ctx->ohci->card.device,
645 				       ar_buffer_bus(ctx, i),
646 				       PAGE_SIZE, DMA_FROM_DEVICE);
647 			__free_page(ctx->pages[i]);
648 		}
649 }
650 
651 static void ar_context_abort(struct ar_context *ctx, const char *error_msg)
652 {
653 	if (reg_read(ctx->ohci, CONTROL_CLEAR(ctx->regs)) & CONTEXT_RUN) {
654 		reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
655 		flush_writes(ctx->ohci);
656 
657 		fw_error("AR error: %s; DMA stopped\n", error_msg);
658 	}
659 	/* FIXME: restart? */
660 }
661 
662 static inline unsigned int ar_next_buffer_index(unsigned int index)
663 {
664 	return (index + 1) % AR_BUFFERS;
665 }
666 
667 static inline unsigned int ar_prev_buffer_index(unsigned int index)
668 {
669 	return (index - 1 + AR_BUFFERS) % AR_BUFFERS;
670 }
671 
672 static inline unsigned int ar_first_buffer_index(struct ar_context *ctx)
673 {
674 	return ar_next_buffer_index(ctx->last_buffer_index);
675 }
676 
677 /*
678  * We search for the buffer that contains the last AR packet DMA data written
679  * by the controller.
680  */
681 static unsigned int ar_search_last_active_buffer(struct ar_context *ctx,
682 						 unsigned int *buffer_offset)
683 {
684 	unsigned int i, next_i, last = ctx->last_buffer_index;
685 	__le16 res_count, next_res_count;
686 
687 	i = ar_first_buffer_index(ctx);
688 	res_count = ACCESS_ONCE(ctx->descriptors[i].res_count);
689 
690 	/* A buffer that is not yet completely filled must be the last one. */
691 	while (i != last && res_count == 0) {
692 
693 		/* Peek at the next descriptor. */
694 		next_i = ar_next_buffer_index(i);
695 		rmb(); /* read descriptors in order */
696 		next_res_count = ACCESS_ONCE(
697 				ctx->descriptors[next_i].res_count);
698 		/*
699 		 * If the next descriptor is still empty, we must stop at this
700 		 * descriptor.
701 		 */
702 		if (next_res_count == cpu_to_le16(PAGE_SIZE)) {
703 			/*
704 			 * The exception is when the DMA data for one packet is
705 			 * split over three buffers; in this case, the middle
706 			 * buffer's descriptor might be never updated by the
707 			 * controller and look still empty, and we have to peek
708 			 * at the third one.
709 			 */
710 			if (MAX_AR_PACKET_SIZE > PAGE_SIZE && i != last) {
711 				next_i = ar_next_buffer_index(next_i);
712 				rmb();
713 				next_res_count = ACCESS_ONCE(
714 					ctx->descriptors[next_i].res_count);
715 				if (next_res_count != cpu_to_le16(PAGE_SIZE))
716 					goto next_buffer_is_active;
717 			}
718 
719 			break;
720 		}
721 
722 next_buffer_is_active:
723 		i = next_i;
724 		res_count = next_res_count;
725 	}
726 
727 	rmb(); /* read res_count before the DMA data */
728 
729 	*buffer_offset = PAGE_SIZE - le16_to_cpu(res_count);
730 	if (*buffer_offset > PAGE_SIZE) {
731 		*buffer_offset = 0;
732 		ar_context_abort(ctx, "corrupted descriptor");
733 	}
734 
735 	return i;
736 }
737 
738 static void ar_sync_buffers_for_cpu(struct ar_context *ctx,
739 				    unsigned int end_buffer_index,
740 				    unsigned int end_buffer_offset)
741 {
742 	unsigned int i;
743 
744 	i = ar_first_buffer_index(ctx);
745 	while (i != end_buffer_index) {
746 		dma_sync_single_for_cpu(ctx->ohci->card.device,
747 					ar_buffer_bus(ctx, i),
748 					PAGE_SIZE, DMA_FROM_DEVICE);
749 		i = ar_next_buffer_index(i);
750 	}
751 	if (end_buffer_offset > 0)
752 		dma_sync_single_for_cpu(ctx->ohci->card.device,
753 					ar_buffer_bus(ctx, i),
754 					end_buffer_offset, DMA_FROM_DEVICE);
755 }
756 
757 #if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
758 #define cond_le32_to_cpu(v) \
759 	(ohci->quirks & QUIRK_BE_HEADERS ? (__force __u32)(v) : le32_to_cpu(v))
760 #else
761 #define cond_le32_to_cpu(v) le32_to_cpu(v)
762 #endif
763 
764 static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
765 {
766 	struct fw_ohci *ohci = ctx->ohci;
767 	struct fw_packet p;
768 	u32 status, length, tcode;
769 	int evt;
770 
771 	p.header[0] = cond_le32_to_cpu(buffer[0]);
772 	p.header[1] = cond_le32_to_cpu(buffer[1]);
773 	p.header[2] = cond_le32_to_cpu(buffer[2]);
774 
775 	tcode = (p.header[0] >> 4) & 0x0f;
776 	switch (tcode) {
777 	case TCODE_WRITE_QUADLET_REQUEST:
778 	case TCODE_READ_QUADLET_RESPONSE:
779 		p.header[3] = (__force __u32) buffer[3];
780 		p.header_length = 16;
781 		p.payload_length = 0;
782 		break;
783 
784 	case TCODE_READ_BLOCK_REQUEST :
785 		p.header[3] = cond_le32_to_cpu(buffer[3]);
786 		p.header_length = 16;
787 		p.payload_length = 0;
788 		break;
789 
790 	case TCODE_WRITE_BLOCK_REQUEST:
791 	case TCODE_READ_BLOCK_RESPONSE:
792 	case TCODE_LOCK_REQUEST:
793 	case TCODE_LOCK_RESPONSE:
794 		p.header[3] = cond_le32_to_cpu(buffer[3]);
795 		p.header_length = 16;
796 		p.payload_length = p.header[3] >> 16;
797 		if (p.payload_length > MAX_ASYNC_PAYLOAD) {
798 			ar_context_abort(ctx, "invalid packet length");
799 			return NULL;
800 		}
801 		break;
802 
803 	case TCODE_WRITE_RESPONSE:
804 	case TCODE_READ_QUADLET_REQUEST:
805 	case OHCI_TCODE_PHY_PACKET:
806 		p.header_length = 12;
807 		p.payload_length = 0;
808 		break;
809 
810 	default:
811 		ar_context_abort(ctx, "invalid tcode");
812 		return NULL;
813 	}
814 
815 	p.payload = (void *) buffer + p.header_length;
816 
817 	/* FIXME: What to do about evt_* errors? */
818 	length = (p.header_length + p.payload_length + 3) / 4;
819 	status = cond_le32_to_cpu(buffer[length]);
820 	evt    = (status >> 16) & 0x1f;
821 
822 	p.ack        = evt - 16;
823 	p.speed      = (status >> 21) & 0x7;
824 	p.timestamp  = status & 0xffff;
825 	p.generation = ohci->request_generation;
826 
827 	log_ar_at_event('R', p.speed, p.header, evt);
828 
829 	/*
830 	 * Several controllers, notably from NEC and VIA, forget to
831 	 * write ack_complete status at PHY packet reception.
832 	 */
833 	if (evt == OHCI1394_evt_no_status &&
834 	    (p.header[0] & 0xff) == (OHCI1394_phy_tcode << 4))
835 		p.ack = ACK_COMPLETE;
836 
837 	/*
838 	 * The OHCI bus reset handler synthesizes a PHY packet with
839 	 * the new generation number when a bus reset happens (see
840 	 * section 8.4.2.3).  This helps us determine when a request
841 	 * was received and make sure we send the response in the same
842 	 * generation.  We only need this for requests; for responses
843 	 * we use the unique tlabel for finding the matching
844 	 * request.
845 	 *
846 	 * Alas some chips sometimes emit bus reset packets with a
847 	 * wrong generation.  We set the correct generation for these
848 	 * at a slightly incorrect time (in bus_reset_tasklet).
849 	 */
850 	if (evt == OHCI1394_evt_bus_reset) {
851 		if (!(ohci->quirks & QUIRK_RESET_PACKET))
852 			ohci->request_generation = (p.header[2] >> 16) & 0xff;
853 	} else if (ctx == &ohci->ar_request_ctx) {
854 		fw_core_handle_request(&ohci->card, &p);
855 	} else {
856 		fw_core_handle_response(&ohci->card, &p);
857 	}
858 
859 	return buffer + length + 1;
860 }
861 
862 static void *handle_ar_packets(struct ar_context *ctx, void *p, void *end)
863 {
864 	void *next;
865 
866 	while (p < end) {
867 		next = handle_ar_packet(ctx, p);
868 		if (!next)
869 			return p;
870 		p = next;
871 	}
872 
873 	return p;
874 }
875 
876 static void ar_recycle_buffers(struct ar_context *ctx, unsigned int end_buffer)
877 {
878 	unsigned int i;
879 
880 	i = ar_first_buffer_index(ctx);
881 	while (i != end_buffer) {
882 		dma_sync_single_for_device(ctx->ohci->card.device,
883 					   ar_buffer_bus(ctx, i),
884 					   PAGE_SIZE, DMA_FROM_DEVICE);
885 		ar_context_link_page(ctx, i);
886 		i = ar_next_buffer_index(i);
887 	}
888 }
889 
890 static void ar_context_tasklet(unsigned long data)
891 {
892 	struct ar_context *ctx = (struct ar_context *)data;
893 	unsigned int end_buffer_index, end_buffer_offset;
894 	void *p, *end;
895 
896 	p = ctx->pointer;
897 	if (!p)
898 		return;
899 
900 	end_buffer_index = ar_search_last_active_buffer(ctx,
901 							&end_buffer_offset);
902 	ar_sync_buffers_for_cpu(ctx, end_buffer_index, end_buffer_offset);
903 	end = ctx->buffer + end_buffer_index * PAGE_SIZE + end_buffer_offset;
904 
905 	if (end_buffer_index < ar_first_buffer_index(ctx)) {
906 		/*
907 		 * The filled part of the overall buffer wraps around; handle
908 		 * all packets up to the buffer end here.  If the last packet
909 		 * wraps around, its tail will be visible after the buffer end
910 		 * because the buffer start pages are mapped there again.
911 		 */
912 		void *buffer_end = ctx->buffer + AR_BUFFERS * PAGE_SIZE;
913 		p = handle_ar_packets(ctx, p, buffer_end);
914 		if (p < buffer_end)
915 			goto error;
916 		/* adjust p to point back into the actual buffer */
917 		p -= AR_BUFFERS * PAGE_SIZE;
918 	}
919 
920 	p = handle_ar_packets(ctx, p, end);
921 	if (p != end) {
922 		if (p > end)
923 			ar_context_abort(ctx, "inconsistent descriptor");
924 		goto error;
925 	}
926 
927 	ctx->pointer = p;
928 	ar_recycle_buffers(ctx, end_buffer_index);
929 
930 	return;
931 
932 error:
933 	ctx->pointer = NULL;
934 }
935 
936 static int ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci,
937 			   unsigned int descriptors_offset, u32 regs)
938 {
939 	unsigned int i;
940 	dma_addr_t dma_addr;
941 	struct page *pages[AR_BUFFERS + AR_WRAPAROUND_PAGES];
942 	struct descriptor *d;
943 
944 	ctx->regs        = regs;
945 	ctx->ohci        = ohci;
946 	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
947 
948 	for (i = 0; i < AR_BUFFERS; i++) {
949 		ctx->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32);
950 		if (!ctx->pages[i])
951 			goto out_of_memory;
952 		dma_addr = dma_map_page(ohci->card.device, ctx->pages[i],
953 					0, PAGE_SIZE, DMA_FROM_DEVICE);
954 		if (dma_mapping_error(ohci->card.device, dma_addr)) {
955 			__free_page(ctx->pages[i]);
956 			ctx->pages[i] = NULL;
957 			goto out_of_memory;
958 		}
959 		set_page_private(ctx->pages[i], dma_addr);
960 	}
961 
962 	for (i = 0; i < AR_BUFFERS; i++)
963 		pages[i]              = ctx->pages[i];
964 	for (i = 0; i < AR_WRAPAROUND_PAGES; i++)
965 		pages[AR_BUFFERS + i] = ctx->pages[i];
966 	ctx->buffer = vm_map_ram(pages, AR_BUFFERS + AR_WRAPAROUND_PAGES,
967 				 -1, PAGE_KERNEL);
968 	if (!ctx->buffer)
969 		goto out_of_memory;
970 
971 	ctx->descriptors     = ohci->misc_buffer     + descriptors_offset;
972 	ctx->descriptors_bus = ohci->misc_buffer_bus + descriptors_offset;
973 
974 	for (i = 0; i < AR_BUFFERS; i++) {
975 		d = &ctx->descriptors[i];
976 		d->req_count      = cpu_to_le16(PAGE_SIZE);
977 		d->control        = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
978 						DESCRIPTOR_STATUS |
979 						DESCRIPTOR_BRANCH_ALWAYS);
980 		d->data_address   = cpu_to_le32(ar_buffer_bus(ctx, i));
981 		d->branch_address = cpu_to_le32(ctx->descriptors_bus +
982 			ar_next_buffer_index(i) * sizeof(struct descriptor));
983 	}
984 
985 	return 0;
986 
987 out_of_memory:
988 	ar_context_release(ctx);
989 
990 	return -ENOMEM;
991 }
992 
993 static void ar_context_run(struct ar_context *ctx)
994 {
995 	unsigned int i;
996 
997 	for (i = 0; i < AR_BUFFERS; i++)
998 		ar_context_link_page(ctx, i);
999 
1000 	ctx->pointer = ctx->buffer;
1001 
1002 	reg_write(ctx->ohci, COMMAND_PTR(ctx->regs), ctx->descriptors_bus | 1);
1003 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN);
1004 	flush_writes(ctx->ohci);
1005 }
1006 
1007 static struct descriptor *find_branch_descriptor(struct descriptor *d, int z)
1008 {
1009 	int b, key;
1010 
1011 	b   = (le16_to_cpu(d->control) & DESCRIPTOR_BRANCH_ALWAYS) >> 2;
1012 	key = (le16_to_cpu(d->control) & DESCRIPTOR_KEY_IMMEDIATE) >> 8;
1013 
1014 	/* figure out which descriptor the branch address goes in */
1015 	if (z == 2 && (b == 3 || key == 2))
1016 		return d;
1017 	else
1018 		return d + z - 1;
1019 }
1020 
1021 static void context_tasklet(unsigned long data)
1022 {
1023 	struct context *ctx = (struct context *) data;
1024 	struct descriptor *d, *last;
1025 	u32 address;
1026 	int z;
1027 	struct descriptor_buffer *desc;
1028 
1029 	desc = list_entry(ctx->buffer_list.next,
1030 			struct descriptor_buffer, list);
1031 	last = ctx->last;
1032 	while (last->branch_address != 0) {
1033 		struct descriptor_buffer *old_desc = desc;
1034 		address = le32_to_cpu(last->branch_address);
1035 		z = address & 0xf;
1036 		address &= ~0xf;
1037 
1038 		/* If the branch address points to a buffer outside of the
1039 		 * current buffer, advance to the next buffer. */
1040 		if (address < desc->buffer_bus ||
1041 				address >= desc->buffer_bus + desc->used)
1042 			desc = list_entry(desc->list.next,
1043 					struct descriptor_buffer, list);
1044 		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
1045 		last = find_branch_descriptor(d, z);
1046 
1047 		if (!ctx->callback(ctx, d, last))
1048 			break;
1049 
1050 		if (old_desc != desc) {
1051 			/* If we've advanced to the next buffer, move the
1052 			 * previous buffer to the free list. */
1053 			unsigned long flags;
1054 			old_desc->used = 0;
1055 			spin_lock_irqsave(&ctx->ohci->lock, flags);
1056 			list_move_tail(&old_desc->list, &ctx->buffer_list);
1057 			spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1058 		}
1059 		ctx->last = last;
1060 	}
1061 }
1062 
1063 /*
1064  * Allocate a new buffer and add it to the list of free buffers for this
1065  * context.  Must be called with ohci->lock held.
1066  */
1067 static int context_add_buffer(struct context *ctx)
1068 {
1069 	struct descriptor_buffer *desc;
1070 	dma_addr_t uninitialized_var(bus_addr);
1071 	int offset;
1072 
1073 	/*
1074 	 * 16MB of descriptors should be far more than enough for any DMA
1075 	 * program.  This will catch run-away userspace or DoS attacks.
1076 	 */
1077 	if (ctx->total_allocation >= 16*1024*1024)
1078 		return -ENOMEM;
1079 
1080 	desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
1081 			&bus_addr, GFP_ATOMIC);
1082 	if (!desc)
1083 		return -ENOMEM;
1084 
1085 	offset = (void *)&desc->buffer - (void *)desc;
1086 	desc->buffer_size = PAGE_SIZE - offset;
1087 	desc->buffer_bus = bus_addr + offset;
1088 	desc->used = 0;
1089 
1090 	list_add_tail(&desc->list, &ctx->buffer_list);
1091 	ctx->total_allocation += PAGE_SIZE;
1092 
1093 	return 0;
1094 }
1095 
1096 static int context_init(struct context *ctx, struct fw_ohci *ohci,
1097 			u32 regs, descriptor_callback_t callback)
1098 {
1099 	ctx->ohci = ohci;
1100 	ctx->regs = regs;
1101 	ctx->total_allocation = 0;
1102 
1103 	INIT_LIST_HEAD(&ctx->buffer_list);
1104 	if (context_add_buffer(ctx) < 0)
1105 		return -ENOMEM;
1106 
1107 	ctx->buffer_tail = list_entry(ctx->buffer_list.next,
1108 			struct descriptor_buffer, list);
1109 
1110 	tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
1111 	ctx->callback = callback;
1112 
1113 	/*
1114 	 * We put a dummy descriptor in the buffer that has a NULL
1115 	 * branch address and looks like it's been sent.  That way we
1116 	 * have a descriptor to append DMA programs to.
1117 	 */
1118 	memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
1119 	ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
1120 	ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
1121 	ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
1122 	ctx->last = ctx->buffer_tail->buffer;
1123 	ctx->prev = ctx->buffer_tail->buffer;
1124 
1125 	return 0;
1126 }
1127 
1128 static void context_release(struct context *ctx)
1129 {
1130 	struct fw_card *card = &ctx->ohci->card;
1131 	struct descriptor_buffer *desc, *tmp;
1132 
1133 	list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
1134 		dma_free_coherent(card->device, PAGE_SIZE, desc,
1135 			desc->buffer_bus -
1136 			((void *)&desc->buffer - (void *)desc));
1137 }
1138 
1139 /* Must be called with ohci->lock held */
1140 static struct descriptor *context_get_descriptors(struct context *ctx,
1141 						  int z, dma_addr_t *d_bus)
1142 {
1143 	struct descriptor *d = NULL;
1144 	struct descriptor_buffer *desc = ctx->buffer_tail;
1145 
1146 	if (z * sizeof(*d) > desc->buffer_size)
1147 		return NULL;
1148 
1149 	if (z * sizeof(*d) > desc->buffer_size - desc->used) {
1150 		/* No room for the descriptor in this buffer, so advance to the
1151 		 * next one. */
1152 
1153 		if (desc->list.next == &ctx->buffer_list) {
1154 			/* If there is no free buffer next in the list,
1155 			 * allocate one. */
1156 			if (context_add_buffer(ctx) < 0)
1157 				return NULL;
1158 		}
1159 		desc = list_entry(desc->list.next,
1160 				struct descriptor_buffer, list);
1161 		ctx->buffer_tail = desc;
1162 	}
1163 
1164 	d = desc->buffer + desc->used / sizeof(*d);
1165 	memset(d, 0, z * sizeof(*d));
1166 	*d_bus = desc->buffer_bus + desc->used;
1167 
1168 	return d;
1169 }
1170 
1171 static void context_run(struct context *ctx, u32 extra)
1172 {
1173 	struct fw_ohci *ohci = ctx->ohci;
1174 
1175 	reg_write(ohci, COMMAND_PTR(ctx->regs),
1176 		  le32_to_cpu(ctx->last->branch_address));
1177 	reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
1178 	reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
1179 	ctx->running = true;
1180 	flush_writes(ohci);
1181 }
1182 
1183 static void context_append(struct context *ctx,
1184 			   struct descriptor *d, int z, int extra)
1185 {
1186 	dma_addr_t d_bus;
1187 	struct descriptor_buffer *desc = ctx->buffer_tail;
1188 
1189 	d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
1190 
1191 	desc->used += (z + extra) * sizeof(*d);
1192 
1193 	wmb(); /* finish init of new descriptors before branch_address update */
1194 	ctx->prev->branch_address = cpu_to_le32(d_bus | z);
1195 	ctx->prev = find_branch_descriptor(d, z);
1196 
1197 	reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
1198 	flush_writes(ctx->ohci);
1199 }
1200 
1201 static void context_stop(struct context *ctx)
1202 {
1203 	u32 reg;
1204 	int i;
1205 
1206 	reg_write(ctx->ohci, CONTROL_CLEAR(ctx->regs), CONTEXT_RUN);
1207 	ctx->running = false;
1208 	flush_writes(ctx->ohci);
1209 
1210 	for (i = 0; i < 10; i++) {
1211 		reg = reg_read(ctx->ohci, CONTROL_SET(ctx->regs));
1212 		if ((reg & CONTEXT_ACTIVE) == 0)
1213 			return;
1214 
1215 		mdelay(1);
1216 	}
1217 	fw_error("Error: DMA context still active (0x%08x)\n", reg);
1218 }
1219 
1220 struct driver_data {
1221 	struct fw_packet *packet;
1222 };
1223 
1224 /*
1225  * This function apppends a packet to the DMA queue for transmission.
1226  * Must always be called with the ochi->lock held to ensure proper
1227  * generation handling and locking around packet queue manipulation.
1228  */
1229 static int at_context_queue_packet(struct context *ctx,
1230 				   struct fw_packet *packet)
1231 {
1232 	struct fw_ohci *ohci = ctx->ohci;
1233 	dma_addr_t d_bus, uninitialized_var(payload_bus);
1234 	struct driver_data *driver_data;
1235 	struct descriptor *d, *last;
1236 	__le32 *header;
1237 	int z, tcode;
1238 
1239 	d = context_get_descriptors(ctx, 4, &d_bus);
1240 	if (d == NULL) {
1241 		packet->ack = RCODE_SEND_ERROR;
1242 		return -1;
1243 	}
1244 
1245 	d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
1246 	d[0].res_count = cpu_to_le16(packet->timestamp);
1247 
1248 	/*
1249 	 * The DMA format for asyncronous link packets is different
1250 	 * from the IEEE1394 layout, so shift the fields around
1251 	 * accordingly.
1252 	 */
1253 
1254 	tcode = (packet->header[0] >> 4) & 0x0f;
1255 	header = (__le32 *) &d[1];
1256 	switch (tcode) {
1257 	case TCODE_WRITE_QUADLET_REQUEST:
1258 	case TCODE_WRITE_BLOCK_REQUEST:
1259 	case TCODE_WRITE_RESPONSE:
1260 	case TCODE_READ_QUADLET_REQUEST:
1261 	case TCODE_READ_BLOCK_REQUEST:
1262 	case TCODE_READ_QUADLET_RESPONSE:
1263 	case TCODE_READ_BLOCK_RESPONSE:
1264 	case TCODE_LOCK_REQUEST:
1265 	case TCODE_LOCK_RESPONSE:
1266 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1267 					(packet->speed << 16));
1268 		header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
1269 					(packet->header[0] & 0xffff0000));
1270 		header[2] = cpu_to_le32(packet->header[2]);
1271 
1272 		if (TCODE_IS_BLOCK_PACKET(tcode))
1273 			header[3] = cpu_to_le32(packet->header[3]);
1274 		else
1275 			header[3] = (__force __le32) packet->header[3];
1276 
1277 		d[0].req_count = cpu_to_le16(packet->header_length);
1278 		break;
1279 
1280 	case TCODE_LINK_INTERNAL:
1281 		header[0] = cpu_to_le32((OHCI1394_phy_tcode << 4) |
1282 					(packet->speed << 16));
1283 		header[1] = cpu_to_le32(packet->header[1]);
1284 		header[2] = cpu_to_le32(packet->header[2]);
1285 		d[0].req_count = cpu_to_le16(12);
1286 
1287 		if (is_ping_packet(&packet->header[1]))
1288 			d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
1289 		break;
1290 
1291 	case TCODE_STREAM_DATA:
1292 		header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
1293 					(packet->speed << 16));
1294 		header[1] = cpu_to_le32(packet->header[0] & 0xffff0000);
1295 		d[0].req_count = cpu_to_le16(8);
1296 		break;
1297 
1298 	default:
1299 		/* BUG(); */
1300 		packet->ack = RCODE_SEND_ERROR;
1301 		return -1;
1302 	}
1303 
1304 	driver_data = (struct driver_data *) &d[3];
1305 	driver_data->packet = packet;
1306 	packet->driver_data = driver_data;
1307 
1308 	if (packet->payload_length > 0) {
1309 		payload_bus =
1310 			dma_map_single(ohci->card.device, packet->payload,
1311 				       packet->payload_length, DMA_TO_DEVICE);
1312 		if (dma_mapping_error(ohci->card.device, payload_bus)) {
1313 			packet->ack = RCODE_SEND_ERROR;
1314 			return -1;
1315 		}
1316 		packet->payload_bus	= payload_bus;
1317 		packet->payload_mapped	= true;
1318 
1319 		d[2].req_count    = cpu_to_le16(packet->payload_length);
1320 		d[2].data_address = cpu_to_le32(payload_bus);
1321 		last = &d[2];
1322 		z = 3;
1323 	} else {
1324 		last = &d[0];
1325 		z = 2;
1326 	}
1327 
1328 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
1329 				     DESCRIPTOR_IRQ_ALWAYS |
1330 				     DESCRIPTOR_BRANCH_ALWAYS);
1331 
1332 	/* FIXME: Document how the locking works. */
1333 	if (ohci->generation != packet->generation) {
1334 		if (packet->payload_mapped)
1335 			dma_unmap_single(ohci->card.device, payload_bus,
1336 					 packet->payload_length, DMA_TO_DEVICE);
1337 		packet->ack = RCODE_GENERATION;
1338 		return -1;
1339 	}
1340 
1341 	context_append(ctx, d, z, 4 - z);
1342 
1343 	if (!ctx->running)
1344 		context_run(ctx, 0);
1345 
1346 	return 0;
1347 }
1348 
1349 static void at_context_flush(struct context *ctx)
1350 {
1351 	tasklet_disable(&ctx->tasklet);
1352 
1353 	ctx->flushing = true;
1354 	context_tasklet((unsigned long)ctx);
1355 	ctx->flushing = false;
1356 
1357 	tasklet_enable(&ctx->tasklet);
1358 }
1359 
1360 static int handle_at_packet(struct context *context,
1361 			    struct descriptor *d,
1362 			    struct descriptor *last)
1363 {
1364 	struct driver_data *driver_data;
1365 	struct fw_packet *packet;
1366 	struct fw_ohci *ohci = context->ohci;
1367 	int evt;
1368 
1369 	if (last->transfer_status == 0 && !context->flushing)
1370 		/* This descriptor isn't done yet, stop iteration. */
1371 		return 0;
1372 
1373 	driver_data = (struct driver_data *) &d[3];
1374 	packet = driver_data->packet;
1375 	if (packet == NULL)
1376 		/* This packet was cancelled, just continue. */
1377 		return 1;
1378 
1379 	if (packet->payload_mapped)
1380 		dma_unmap_single(ohci->card.device, packet->payload_bus,
1381 				 packet->payload_length, DMA_TO_DEVICE);
1382 
1383 	evt = le16_to_cpu(last->transfer_status) & 0x1f;
1384 	packet->timestamp = le16_to_cpu(last->res_count);
1385 
1386 	log_ar_at_event('T', packet->speed, packet->header, evt);
1387 
1388 	switch (evt) {
1389 	case OHCI1394_evt_timeout:
1390 		/* Async response transmit timed out. */
1391 		packet->ack = RCODE_CANCELLED;
1392 		break;
1393 
1394 	case OHCI1394_evt_flushed:
1395 		/*
1396 		 * The packet was flushed should give same error as
1397 		 * when we try to use a stale generation count.
1398 		 */
1399 		packet->ack = RCODE_GENERATION;
1400 		break;
1401 
1402 	case OHCI1394_evt_missing_ack:
1403 		if (context->flushing)
1404 			packet->ack = RCODE_GENERATION;
1405 		else {
1406 			/*
1407 			 * Using a valid (current) generation count, but the
1408 			 * node is not on the bus or not sending acks.
1409 			 */
1410 			packet->ack = RCODE_NO_ACK;
1411 		}
1412 		break;
1413 
1414 	case ACK_COMPLETE + 0x10:
1415 	case ACK_PENDING + 0x10:
1416 	case ACK_BUSY_X + 0x10:
1417 	case ACK_BUSY_A + 0x10:
1418 	case ACK_BUSY_B + 0x10:
1419 	case ACK_DATA_ERROR + 0x10:
1420 	case ACK_TYPE_ERROR + 0x10:
1421 		packet->ack = evt - 0x10;
1422 		break;
1423 
1424 	case OHCI1394_evt_no_status:
1425 		if (context->flushing) {
1426 			packet->ack = RCODE_GENERATION;
1427 			break;
1428 		}
1429 		/* fall through */
1430 
1431 	default:
1432 		packet->ack = RCODE_SEND_ERROR;
1433 		break;
1434 	}
1435 
1436 	packet->callback(packet, &ohci->card, packet->ack);
1437 
1438 	return 1;
1439 }
1440 
1441 #define HEADER_GET_DESTINATION(q)	(((q) >> 16) & 0xffff)
1442 #define HEADER_GET_TCODE(q)		(((q) >> 4) & 0x0f)
1443 #define HEADER_GET_OFFSET_HIGH(q)	(((q) >> 0) & 0xffff)
1444 #define HEADER_GET_DATA_LENGTH(q)	(((q) >> 16) & 0xffff)
1445 #define HEADER_GET_EXTENDED_TCODE(q)	(((q) >> 0) & 0xffff)
1446 
1447 static void handle_local_rom(struct fw_ohci *ohci,
1448 			     struct fw_packet *packet, u32 csr)
1449 {
1450 	struct fw_packet response;
1451 	int tcode, length, i;
1452 
1453 	tcode = HEADER_GET_TCODE(packet->header[0]);
1454 	if (TCODE_IS_BLOCK_PACKET(tcode))
1455 		length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1456 	else
1457 		length = 4;
1458 
1459 	i = csr - CSR_CONFIG_ROM;
1460 	if (i + length > CONFIG_ROM_SIZE) {
1461 		fw_fill_response(&response, packet->header,
1462 				 RCODE_ADDRESS_ERROR, NULL, 0);
1463 	} else if (!TCODE_IS_READ_REQUEST(tcode)) {
1464 		fw_fill_response(&response, packet->header,
1465 				 RCODE_TYPE_ERROR, NULL, 0);
1466 	} else {
1467 		fw_fill_response(&response, packet->header, RCODE_COMPLETE,
1468 				 (void *) ohci->config_rom + i, length);
1469 	}
1470 
1471 	fw_core_handle_response(&ohci->card, &response);
1472 }
1473 
1474 static void handle_local_lock(struct fw_ohci *ohci,
1475 			      struct fw_packet *packet, u32 csr)
1476 {
1477 	struct fw_packet response;
1478 	int tcode, length, ext_tcode, sel, try;
1479 	__be32 *payload, lock_old;
1480 	u32 lock_arg, lock_data;
1481 
1482 	tcode = HEADER_GET_TCODE(packet->header[0]);
1483 	length = HEADER_GET_DATA_LENGTH(packet->header[3]);
1484 	payload = packet->payload;
1485 	ext_tcode = HEADER_GET_EXTENDED_TCODE(packet->header[3]);
1486 
1487 	if (tcode == TCODE_LOCK_REQUEST &&
1488 	    ext_tcode == EXTCODE_COMPARE_SWAP && length == 8) {
1489 		lock_arg = be32_to_cpu(payload[0]);
1490 		lock_data = be32_to_cpu(payload[1]);
1491 	} else if (tcode == TCODE_READ_QUADLET_REQUEST) {
1492 		lock_arg = 0;
1493 		lock_data = 0;
1494 	} else {
1495 		fw_fill_response(&response, packet->header,
1496 				 RCODE_TYPE_ERROR, NULL, 0);
1497 		goto out;
1498 	}
1499 
1500 	sel = (csr - CSR_BUS_MANAGER_ID) / 4;
1501 	reg_write(ohci, OHCI1394_CSRData, lock_data);
1502 	reg_write(ohci, OHCI1394_CSRCompareData, lock_arg);
1503 	reg_write(ohci, OHCI1394_CSRControl, sel);
1504 
1505 	for (try = 0; try < 20; try++)
1506 		if (reg_read(ohci, OHCI1394_CSRControl) & 0x80000000) {
1507 			lock_old = cpu_to_be32(reg_read(ohci,
1508 							OHCI1394_CSRData));
1509 			fw_fill_response(&response, packet->header,
1510 					 RCODE_COMPLETE,
1511 					 &lock_old, sizeof(lock_old));
1512 			goto out;
1513 		}
1514 
1515 	fw_error("swap not done (CSR lock timeout)\n");
1516 	fw_fill_response(&response, packet->header, RCODE_BUSY, NULL, 0);
1517 
1518  out:
1519 	fw_core_handle_response(&ohci->card, &response);
1520 }
1521 
1522 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
1523 {
1524 	u64 offset, csr;
1525 
1526 	if (ctx == &ctx->ohci->at_request_ctx) {
1527 		packet->ack = ACK_PENDING;
1528 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1529 	}
1530 
1531 	offset =
1532 		((unsigned long long)
1533 		 HEADER_GET_OFFSET_HIGH(packet->header[1]) << 32) |
1534 		packet->header[2];
1535 	csr = offset - CSR_REGISTER_BASE;
1536 
1537 	/* Handle config rom reads. */
1538 	if (csr >= CSR_CONFIG_ROM && csr < CSR_CONFIG_ROM_END)
1539 		handle_local_rom(ctx->ohci, packet, csr);
1540 	else switch (csr) {
1541 	case CSR_BUS_MANAGER_ID:
1542 	case CSR_BANDWIDTH_AVAILABLE:
1543 	case CSR_CHANNELS_AVAILABLE_HI:
1544 	case CSR_CHANNELS_AVAILABLE_LO:
1545 		handle_local_lock(ctx->ohci, packet, csr);
1546 		break;
1547 	default:
1548 		if (ctx == &ctx->ohci->at_request_ctx)
1549 			fw_core_handle_request(&ctx->ohci->card, packet);
1550 		else
1551 			fw_core_handle_response(&ctx->ohci->card, packet);
1552 		break;
1553 	}
1554 
1555 	if (ctx == &ctx->ohci->at_response_ctx) {
1556 		packet->ack = ACK_COMPLETE;
1557 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1558 	}
1559 }
1560 
1561 static void at_context_transmit(struct context *ctx, struct fw_packet *packet)
1562 {
1563 	unsigned long flags;
1564 	int ret;
1565 
1566 	spin_lock_irqsave(&ctx->ohci->lock, flags);
1567 
1568 	if (HEADER_GET_DESTINATION(packet->header[0]) == ctx->ohci->node_id &&
1569 	    ctx->ohci->generation == packet->generation) {
1570 		spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1571 		handle_local_request(ctx, packet);
1572 		return;
1573 	}
1574 
1575 	ret = at_context_queue_packet(ctx, packet);
1576 	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
1577 
1578 	if (ret < 0)
1579 		packet->callback(packet, &ctx->ohci->card, packet->ack);
1580 
1581 }
1582 
1583 static void detect_dead_context(struct fw_ohci *ohci,
1584 				const char *name, unsigned int regs)
1585 {
1586 	u32 ctl;
1587 
1588 	ctl = reg_read(ohci, CONTROL_SET(regs));
1589 	if (ctl & CONTEXT_DEAD) {
1590 #ifdef CONFIG_FIREWIRE_OHCI_DEBUG
1591 		fw_error("DMA context %s has stopped, error code: %s\n",
1592 			 name, evts[ctl & 0x1f]);
1593 #else
1594 		fw_error("DMA context %s has stopped, error code: %#x\n",
1595 			 name, ctl & 0x1f);
1596 #endif
1597 	}
1598 }
1599 
1600 static void handle_dead_contexts(struct fw_ohci *ohci)
1601 {
1602 	unsigned int i;
1603 	char name[8];
1604 
1605 	detect_dead_context(ohci, "ATReq", OHCI1394_AsReqTrContextBase);
1606 	detect_dead_context(ohci, "ATRsp", OHCI1394_AsRspTrContextBase);
1607 	detect_dead_context(ohci, "ARReq", OHCI1394_AsReqRcvContextBase);
1608 	detect_dead_context(ohci, "ARRsp", OHCI1394_AsRspRcvContextBase);
1609 	for (i = 0; i < 32; ++i) {
1610 		if (!(ohci->it_context_support & (1 << i)))
1611 			continue;
1612 		sprintf(name, "IT%u", i);
1613 		detect_dead_context(ohci, name, OHCI1394_IsoXmitContextBase(i));
1614 	}
1615 	for (i = 0; i < 32; ++i) {
1616 		if (!(ohci->ir_context_support & (1 << i)))
1617 			continue;
1618 		sprintf(name, "IR%u", i);
1619 		detect_dead_context(ohci, name, OHCI1394_IsoRcvContextBase(i));
1620 	}
1621 	/* TODO: maybe try to flush and restart the dead contexts */
1622 }
1623 
1624 static u32 cycle_timer_ticks(u32 cycle_timer)
1625 {
1626 	u32 ticks;
1627 
1628 	ticks = cycle_timer & 0xfff;
1629 	ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
1630 	ticks += (3072 * 8000) * (cycle_timer >> 25);
1631 
1632 	return ticks;
1633 }
1634 
1635 /*
1636  * Some controllers exhibit one or more of the following bugs when updating the
1637  * iso cycle timer register:
1638  *  - When the lowest six bits are wrapping around to zero, a read that happens
1639  *    at the same time will return garbage in the lowest ten bits.
1640  *  - When the cycleOffset field wraps around to zero, the cycleCount field is
1641  *    not incremented for about 60 ns.
1642  *  - Occasionally, the entire register reads zero.
1643  *
1644  * To catch these, we read the register three times and ensure that the
1645  * difference between each two consecutive reads is approximately the same, i.e.
1646  * less than twice the other.  Furthermore, any negative difference indicates an
1647  * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
1648  * execute, so we have enough precision to compute the ratio of the differences.)
1649  */
1650 static u32 get_cycle_time(struct fw_ohci *ohci)
1651 {
1652 	u32 c0, c1, c2;
1653 	u32 t0, t1, t2;
1654 	s32 diff01, diff12;
1655 	int i;
1656 
1657 	c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1658 
1659 	if (ohci->quirks & QUIRK_CYCLE_TIMER) {
1660 		i = 0;
1661 		c1 = c2;
1662 		c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1663 		do {
1664 			c0 = c1;
1665 			c1 = c2;
1666 			c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
1667 			t0 = cycle_timer_ticks(c0);
1668 			t1 = cycle_timer_ticks(c1);
1669 			t2 = cycle_timer_ticks(c2);
1670 			diff01 = t1 - t0;
1671 			diff12 = t2 - t1;
1672 		} while ((diff01 <= 0 || diff12 <= 0 ||
1673 			  diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
1674 			 && i++ < 20);
1675 	}
1676 
1677 	return c2;
1678 }
1679 
1680 /*
1681  * This function has to be called at least every 64 seconds.  The bus_time
1682  * field stores not only the upper 25 bits of the BUS_TIME register but also
1683  * the most significant bit of the cycle timer in bit 6 so that we can detect
1684  * changes in this bit.
1685  */
1686 static u32 update_bus_time(struct fw_ohci *ohci)
1687 {
1688 	u32 cycle_time_seconds = get_cycle_time(ohci) >> 25;
1689 
1690 	if ((ohci->bus_time & 0x40) != (cycle_time_seconds & 0x40))
1691 		ohci->bus_time += 0x40;
1692 
1693 	return ohci->bus_time | cycle_time_seconds;
1694 }
1695 
1696 static void bus_reset_tasklet(unsigned long data)
1697 {
1698 	struct fw_ohci *ohci = (struct fw_ohci *)data;
1699 	int self_id_count, i, j, reg;
1700 	int generation, new_generation;
1701 	unsigned long flags;
1702 	void *free_rom = NULL;
1703 	dma_addr_t free_rom_bus = 0;
1704 	bool is_new_root;
1705 
1706 	reg = reg_read(ohci, OHCI1394_NodeID);
1707 	if (!(reg & OHCI1394_NodeID_idValid)) {
1708 		fw_notify("node ID not valid, new bus reset in progress\n");
1709 		return;
1710 	}
1711 	if ((reg & OHCI1394_NodeID_nodeNumber) == 63) {
1712 		fw_notify("malconfigured bus\n");
1713 		return;
1714 	}
1715 	ohci->node_id = reg & (OHCI1394_NodeID_busNumber |
1716 			       OHCI1394_NodeID_nodeNumber);
1717 
1718 	is_new_root = (reg & OHCI1394_NodeID_root) != 0;
1719 	if (!(ohci->is_root && is_new_root))
1720 		reg_write(ohci, OHCI1394_LinkControlSet,
1721 			  OHCI1394_LinkControl_cycleMaster);
1722 	ohci->is_root = is_new_root;
1723 
1724 	reg = reg_read(ohci, OHCI1394_SelfIDCount);
1725 	if (reg & OHCI1394_SelfIDCount_selfIDError) {
1726 		fw_notify("inconsistent self IDs\n");
1727 		return;
1728 	}
1729 	/*
1730 	 * The count in the SelfIDCount register is the number of
1731 	 * bytes in the self ID receive buffer.  Since we also receive
1732 	 * the inverted quadlets and a header quadlet, we shift one
1733 	 * bit extra to get the actual number of self IDs.
1734 	 */
1735 	self_id_count = (reg >> 3) & 0xff;
1736 	if (self_id_count == 0 || self_id_count > 252) {
1737 		fw_notify("inconsistent self IDs\n");
1738 		return;
1739 	}
1740 	generation = (cond_le32_to_cpu(ohci->self_id_cpu[0]) >> 16) & 0xff;
1741 	rmb();
1742 
1743 	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
1744 		if (ohci->self_id_cpu[i] != ~ohci->self_id_cpu[i + 1]) {
1745 			fw_notify("inconsistent self IDs\n");
1746 			return;
1747 		}
1748 		ohci->self_id_buffer[j] =
1749 				cond_le32_to_cpu(ohci->self_id_cpu[i]);
1750 	}
1751 	rmb();
1752 
1753 	/*
1754 	 * Check the consistency of the self IDs we just read.  The
1755 	 * problem we face is that a new bus reset can start while we
1756 	 * read out the self IDs from the DMA buffer. If this happens,
1757 	 * the DMA buffer will be overwritten with new self IDs and we
1758 	 * will read out inconsistent data.  The OHCI specification
1759 	 * (section 11.2) recommends a technique similar to
1760 	 * linux/seqlock.h, where we remember the generation of the
1761 	 * self IDs in the buffer before reading them out and compare
1762 	 * it to the current generation after reading them out.  If
1763 	 * the two generations match we know we have a consistent set
1764 	 * of self IDs.
1765 	 */
1766 
1767 	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
1768 	if (new_generation != generation) {
1769 		fw_notify("recursive bus reset detected, "
1770 			  "discarding self ids\n");
1771 		return;
1772 	}
1773 
1774 	/* FIXME: Document how the locking works. */
1775 	spin_lock_irqsave(&ohci->lock, flags);
1776 
1777 	ohci->generation = -1; /* prevent AT packet queueing */
1778 	context_stop(&ohci->at_request_ctx);
1779 	context_stop(&ohci->at_response_ctx);
1780 
1781 	spin_unlock_irqrestore(&ohci->lock, flags);
1782 
1783 	/*
1784 	 * Per OHCI 1.2 draft, clause 7.2.3.3, hardware may leave unsent
1785 	 * packets in the AT queues and software needs to drain them.
1786 	 * Some OHCI 1.1 controllers (JMicron) apparently require this too.
1787 	 */
1788 	at_context_flush(&ohci->at_request_ctx);
1789 	at_context_flush(&ohci->at_response_ctx);
1790 
1791 	spin_lock_irqsave(&ohci->lock, flags);
1792 
1793 	ohci->generation = generation;
1794 	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
1795 
1796 	if (ohci->quirks & QUIRK_RESET_PACKET)
1797 		ohci->request_generation = generation;
1798 
1799 	/*
1800 	 * This next bit is unrelated to the AT context stuff but we
1801 	 * have to do it under the spinlock also.  If a new config rom
1802 	 * was set up before this reset, the old one is now no longer
1803 	 * in use and we can free it. Update the config rom pointers
1804 	 * to point to the current config rom and clear the
1805 	 * next_config_rom pointer so a new update can take place.
1806 	 */
1807 
1808 	if (ohci->next_config_rom != NULL) {
1809 		if (ohci->next_config_rom != ohci->config_rom) {
1810 			free_rom      = ohci->config_rom;
1811 			free_rom_bus  = ohci->config_rom_bus;
1812 		}
1813 		ohci->config_rom      = ohci->next_config_rom;
1814 		ohci->config_rom_bus  = ohci->next_config_rom_bus;
1815 		ohci->next_config_rom = NULL;
1816 
1817 		/*
1818 		 * Restore config_rom image and manually update
1819 		 * config_rom registers.  Writing the header quadlet
1820 		 * will indicate that the config rom is ready, so we
1821 		 * do that last.
1822 		 */
1823 		reg_write(ohci, OHCI1394_BusOptions,
1824 			  be32_to_cpu(ohci->config_rom[2]));
1825 		ohci->config_rom[0] = ohci->next_header;
1826 		reg_write(ohci, OHCI1394_ConfigROMhdr,
1827 			  be32_to_cpu(ohci->next_header));
1828 	}
1829 
1830 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
1831 	reg_write(ohci, OHCI1394_PhyReqFilterHiSet, ~0);
1832 	reg_write(ohci, OHCI1394_PhyReqFilterLoSet, ~0);
1833 #endif
1834 
1835 	spin_unlock_irqrestore(&ohci->lock, flags);
1836 
1837 	if (free_rom)
1838 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
1839 				  free_rom, free_rom_bus);
1840 
1841 	log_selfids(ohci->node_id, generation,
1842 		    self_id_count, ohci->self_id_buffer);
1843 
1844 	fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
1845 				 self_id_count, ohci->self_id_buffer,
1846 				 ohci->csr_state_setclear_abdicate);
1847 	ohci->csr_state_setclear_abdicate = false;
1848 }
1849 
1850 static irqreturn_t irq_handler(int irq, void *data)
1851 {
1852 	struct fw_ohci *ohci = data;
1853 	u32 event, iso_event;
1854 	int i;
1855 
1856 	event = reg_read(ohci, OHCI1394_IntEventClear);
1857 
1858 	if (!event || !~event)
1859 		return IRQ_NONE;
1860 
1861 	/*
1862 	 * busReset and postedWriteErr must not be cleared yet
1863 	 * (OHCI 1.1 clauses 7.2.3.2 and 13.2.8.1)
1864 	 */
1865 	reg_write(ohci, OHCI1394_IntEventClear,
1866 		  event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
1867 	log_irqs(event);
1868 
1869 	if (event & OHCI1394_selfIDComplete)
1870 		tasklet_schedule(&ohci->bus_reset_tasklet);
1871 
1872 	if (event & OHCI1394_RQPkt)
1873 		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
1874 
1875 	if (event & OHCI1394_RSPkt)
1876 		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
1877 
1878 	if (event & OHCI1394_reqTxComplete)
1879 		tasklet_schedule(&ohci->at_request_ctx.tasklet);
1880 
1881 	if (event & OHCI1394_respTxComplete)
1882 		tasklet_schedule(&ohci->at_response_ctx.tasklet);
1883 
1884 	if (event & OHCI1394_isochRx) {
1885 		iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventClear);
1886 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
1887 
1888 		while (iso_event) {
1889 			i = ffs(iso_event) - 1;
1890 			tasklet_schedule(
1891 				&ohci->ir_context_list[i].context.tasklet);
1892 			iso_event &= ~(1 << i);
1893 		}
1894 	}
1895 
1896 	if (event & OHCI1394_isochTx) {
1897 		iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventClear);
1898 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
1899 
1900 		while (iso_event) {
1901 			i = ffs(iso_event) - 1;
1902 			tasklet_schedule(
1903 				&ohci->it_context_list[i].context.tasklet);
1904 			iso_event &= ~(1 << i);
1905 		}
1906 	}
1907 
1908 	if (unlikely(event & OHCI1394_regAccessFail))
1909 		fw_error("Register access failure - "
1910 			 "please notify linux1394-devel@lists.sf.net\n");
1911 
1912 	if (unlikely(event & OHCI1394_postedWriteErr)) {
1913 		reg_read(ohci, OHCI1394_PostedWriteAddressHi);
1914 		reg_read(ohci, OHCI1394_PostedWriteAddressLo);
1915 		reg_write(ohci, OHCI1394_IntEventClear,
1916 			  OHCI1394_postedWriteErr);
1917 		fw_error("PCI posted write error\n");
1918 	}
1919 
1920 	if (unlikely(event & OHCI1394_cycleTooLong)) {
1921 		if (printk_ratelimit())
1922 			fw_notify("isochronous cycle too long\n");
1923 		reg_write(ohci, OHCI1394_LinkControlSet,
1924 			  OHCI1394_LinkControl_cycleMaster);
1925 	}
1926 
1927 	if (unlikely(event & OHCI1394_cycleInconsistent)) {
1928 		/*
1929 		 * We need to clear this event bit in order to make
1930 		 * cycleMatch isochronous I/O work.  In theory we should
1931 		 * stop active cycleMatch iso contexts now and restart
1932 		 * them at least two cycles later.  (FIXME?)
1933 		 */
1934 		if (printk_ratelimit())
1935 			fw_notify("isochronous cycle inconsistent\n");
1936 	}
1937 
1938 	if (unlikely(event & OHCI1394_unrecoverableError))
1939 		handle_dead_contexts(ohci);
1940 
1941 	if (event & OHCI1394_cycle64Seconds) {
1942 		spin_lock(&ohci->lock);
1943 		update_bus_time(ohci);
1944 		spin_unlock(&ohci->lock);
1945 	} else
1946 		flush_writes(ohci);
1947 
1948 	return IRQ_HANDLED;
1949 }
1950 
1951 static int software_reset(struct fw_ohci *ohci)
1952 {
1953 	int i;
1954 
1955 	reg_write(ohci, OHCI1394_HCControlSet, OHCI1394_HCControl_softReset);
1956 
1957 	for (i = 0; i < OHCI_LOOP_COUNT; i++) {
1958 		if ((reg_read(ohci, OHCI1394_HCControlSet) &
1959 		     OHCI1394_HCControl_softReset) == 0)
1960 			return 0;
1961 		msleep(1);
1962 	}
1963 
1964 	return -EBUSY;
1965 }
1966 
1967 static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
1968 {
1969 	size_t size = length * 4;
1970 
1971 	memcpy(dest, src, size);
1972 	if (size < CONFIG_ROM_SIZE)
1973 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
1974 }
1975 
1976 static int configure_1394a_enhancements(struct fw_ohci *ohci)
1977 {
1978 	bool enable_1394a;
1979 	int ret, clear, set, offset;
1980 
1981 	/* Check if the driver should configure link and PHY. */
1982 	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
1983 	      OHCI1394_HCControl_programPhyEnable))
1984 		return 0;
1985 
1986 	/* Paranoia: check whether the PHY supports 1394a, too. */
1987 	enable_1394a = false;
1988 	ret = read_phy_reg(ohci, 2);
1989 	if (ret < 0)
1990 		return ret;
1991 	if ((ret & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
1992 		ret = read_paged_phy_reg(ohci, 1, 8);
1993 		if (ret < 0)
1994 			return ret;
1995 		if (ret >= 1)
1996 			enable_1394a = true;
1997 	}
1998 
1999 	if (ohci->quirks & QUIRK_NO_1394A)
2000 		enable_1394a = false;
2001 
2002 	/* Configure PHY and link consistently. */
2003 	if (enable_1394a) {
2004 		clear = 0;
2005 		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2006 	} else {
2007 		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
2008 		set = 0;
2009 	}
2010 	ret = update_phy_reg(ohci, 5, clear, set);
2011 	if (ret < 0)
2012 		return ret;
2013 
2014 	if (enable_1394a)
2015 		offset = OHCI1394_HCControlSet;
2016 	else
2017 		offset = OHCI1394_HCControlClear;
2018 	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
2019 
2020 	/* Clean up: configuration has been taken care of. */
2021 	reg_write(ohci, OHCI1394_HCControlClear,
2022 		  OHCI1394_HCControl_programPhyEnable);
2023 
2024 	return 0;
2025 }
2026 
2027 static int ohci_enable(struct fw_card *card,
2028 		       const __be32 *config_rom, size_t length)
2029 {
2030 	struct fw_ohci *ohci = fw_ohci(card);
2031 	struct pci_dev *dev = to_pci_dev(card->device);
2032 	u32 lps, seconds, version, irqs;
2033 	int i, ret;
2034 
2035 	if (software_reset(ohci)) {
2036 		fw_error("Failed to reset ohci card.\n");
2037 		return -EBUSY;
2038 	}
2039 
2040 	/*
2041 	 * Now enable LPS, which we need in order to start accessing
2042 	 * most of the registers.  In fact, on some cards (ALI M5251),
2043 	 * accessing registers in the SClk domain without LPS enabled
2044 	 * will lock up the machine.  Wait 50msec to make sure we have
2045 	 * full link enabled.  However, with some cards (well, at least
2046 	 * a JMicron PCIe card), we have to try again sometimes.
2047 	 */
2048 	reg_write(ohci, OHCI1394_HCControlSet,
2049 		  OHCI1394_HCControl_LPS |
2050 		  OHCI1394_HCControl_postedWriteEnable);
2051 	flush_writes(ohci);
2052 
2053 	for (lps = 0, i = 0; !lps && i < 3; i++) {
2054 		msleep(50);
2055 		lps = reg_read(ohci, OHCI1394_HCControlSet) &
2056 		      OHCI1394_HCControl_LPS;
2057 	}
2058 
2059 	if (!lps) {
2060 		fw_error("Failed to set Link Power Status\n");
2061 		return -EIO;
2062 	}
2063 
2064 	reg_write(ohci, OHCI1394_HCControlClear,
2065 		  OHCI1394_HCControl_noByteSwapData);
2066 
2067 	reg_write(ohci, OHCI1394_SelfIDBuffer, ohci->self_id_bus);
2068 	reg_write(ohci, OHCI1394_LinkControlSet,
2069 		  OHCI1394_LinkControl_rcvSelfID |
2070 		  OHCI1394_LinkControl_rcvPhyPkt |
2071 		  OHCI1394_LinkControl_cycleTimerEnable |
2072 		  OHCI1394_LinkControl_cycleMaster);
2073 
2074 	reg_write(ohci, OHCI1394_ATRetries,
2075 		  OHCI1394_MAX_AT_REQ_RETRIES |
2076 		  (OHCI1394_MAX_AT_RESP_RETRIES << 4) |
2077 		  (OHCI1394_MAX_PHYS_RESP_RETRIES << 8) |
2078 		  (200 << 16));
2079 
2080 	seconds = lower_32_bits(get_seconds());
2081 	reg_write(ohci, OHCI1394_IsochronousCycleTimer, seconds << 25);
2082 	ohci->bus_time = seconds & ~0x3f;
2083 
2084 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
2085 	if (version >= OHCI_VERSION_1_1) {
2086 		reg_write(ohci, OHCI1394_InitialChannelsAvailableHi,
2087 			  0xfffffffe);
2088 		card->broadcast_channel_auto_allocated = true;
2089 	}
2090 
2091 	/* Get implemented bits of the priority arbitration request counter. */
2092 	reg_write(ohci, OHCI1394_FairnessControl, 0x3f);
2093 	ohci->pri_req_max = reg_read(ohci, OHCI1394_FairnessControl) & 0x3f;
2094 	reg_write(ohci, OHCI1394_FairnessControl, 0);
2095 	card->priority_budget_implemented = ohci->pri_req_max != 0;
2096 
2097 	ar_context_run(&ohci->ar_request_ctx);
2098 	ar_context_run(&ohci->ar_response_ctx);
2099 
2100 	reg_write(ohci, OHCI1394_PhyUpperBound, 0x00010000);
2101 	reg_write(ohci, OHCI1394_IntEventClear, ~0);
2102 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
2103 
2104 	ret = configure_1394a_enhancements(ohci);
2105 	if (ret < 0)
2106 		return ret;
2107 
2108 	/* Activate link_on bit and contender bit in our self ID packets.*/
2109 	ret = ohci_update_phy_reg(card, 4, 0, PHY_LINK_ACTIVE | PHY_CONTENDER);
2110 	if (ret < 0)
2111 		return ret;
2112 
2113 	/*
2114 	 * When the link is not yet enabled, the atomic config rom
2115 	 * update mechanism described below in ohci_set_config_rom()
2116 	 * is not active.  We have to update ConfigRomHeader and
2117 	 * BusOptions manually, and the write to ConfigROMmap takes
2118 	 * effect immediately.  We tie this to the enabling of the
2119 	 * link, so we have a valid config rom before enabling - the
2120 	 * OHCI requires that ConfigROMhdr and BusOptions have valid
2121 	 * values before enabling.
2122 	 *
2123 	 * However, when the ConfigROMmap is written, some controllers
2124 	 * always read back quadlets 0 and 2 from the config rom to
2125 	 * the ConfigRomHeader and BusOptions registers on bus reset.
2126 	 * They shouldn't do that in this initial case where the link
2127 	 * isn't enabled.  This means we have to use the same
2128 	 * workaround here, setting the bus header to 0 and then write
2129 	 * the right values in the bus reset tasklet.
2130 	 */
2131 
2132 	if (config_rom) {
2133 		ohci->next_config_rom =
2134 			dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2135 					   &ohci->next_config_rom_bus,
2136 					   GFP_KERNEL);
2137 		if (ohci->next_config_rom == NULL)
2138 			return -ENOMEM;
2139 
2140 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2141 	} else {
2142 		/*
2143 		 * In the suspend case, config_rom is NULL, which
2144 		 * means that we just reuse the old config rom.
2145 		 */
2146 		ohci->next_config_rom = ohci->config_rom;
2147 		ohci->next_config_rom_bus = ohci->config_rom_bus;
2148 	}
2149 
2150 	ohci->next_header = ohci->next_config_rom[0];
2151 	ohci->next_config_rom[0] = 0;
2152 	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
2153 	reg_write(ohci, OHCI1394_BusOptions,
2154 		  be32_to_cpu(ohci->next_config_rom[2]));
2155 	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
2156 
2157 	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
2158 
2159 	if (!(ohci->quirks & QUIRK_NO_MSI))
2160 		pci_enable_msi(dev);
2161 	if (request_irq(dev->irq, irq_handler,
2162 			pci_dev_msi_enabled(dev) ? 0 : IRQF_SHARED,
2163 			ohci_driver_name, ohci)) {
2164 		fw_error("Failed to allocate interrupt %d.\n", dev->irq);
2165 		pci_disable_msi(dev);
2166 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2167 				  ohci->config_rom, ohci->config_rom_bus);
2168 		return -EIO;
2169 	}
2170 
2171 	irqs =	OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
2172 		OHCI1394_RQPkt | OHCI1394_RSPkt |
2173 		OHCI1394_isochTx | OHCI1394_isochRx |
2174 		OHCI1394_postedWriteErr |
2175 		OHCI1394_selfIDComplete |
2176 		OHCI1394_regAccessFail |
2177 		OHCI1394_cycle64Seconds |
2178 		OHCI1394_cycleInconsistent |
2179 		OHCI1394_unrecoverableError |
2180 		OHCI1394_cycleTooLong |
2181 		OHCI1394_masterIntEnable;
2182 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
2183 		irqs |= OHCI1394_busReset;
2184 	reg_write(ohci, OHCI1394_IntMaskSet, irqs);
2185 
2186 	reg_write(ohci, OHCI1394_HCControlSet,
2187 		  OHCI1394_HCControl_linkEnable |
2188 		  OHCI1394_HCControl_BIBimageValid);
2189 	flush_writes(ohci);
2190 
2191 	/* We are ready to go, reset bus to finish initialization. */
2192 	fw_schedule_bus_reset(&ohci->card, false, true);
2193 
2194 	return 0;
2195 }
2196 
2197 static int ohci_set_config_rom(struct fw_card *card,
2198 			       const __be32 *config_rom, size_t length)
2199 {
2200 	struct fw_ohci *ohci;
2201 	unsigned long flags;
2202 	int ret = -EBUSY;
2203 	__be32 *next_config_rom;
2204 	dma_addr_t uninitialized_var(next_config_rom_bus);
2205 
2206 	ohci = fw_ohci(card);
2207 
2208 	/*
2209 	 * When the OHCI controller is enabled, the config rom update
2210 	 * mechanism is a bit tricky, but easy enough to use.  See
2211 	 * section 5.5.6 in the OHCI specification.
2212 	 *
2213 	 * The OHCI controller caches the new config rom address in a
2214 	 * shadow register (ConfigROMmapNext) and needs a bus reset
2215 	 * for the changes to take place.  When the bus reset is
2216 	 * detected, the controller loads the new values for the
2217 	 * ConfigRomHeader and BusOptions registers from the specified
2218 	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
2219 	 * shadow register. All automatically and atomically.
2220 	 *
2221 	 * Now, there's a twist to this story.  The automatic load of
2222 	 * ConfigRomHeader and BusOptions doesn't honor the
2223 	 * noByteSwapData bit, so with a be32 config rom, the
2224 	 * controller will load be32 values in to these registers
2225 	 * during the atomic update, even on litte endian
2226 	 * architectures.  The workaround we use is to put a 0 in the
2227 	 * header quadlet; 0 is endian agnostic and means that the
2228 	 * config rom isn't ready yet.  In the bus reset tasklet we
2229 	 * then set up the real values for the two registers.
2230 	 *
2231 	 * We use ohci->lock to avoid racing with the code that sets
2232 	 * ohci->next_config_rom to NULL (see bus_reset_tasklet).
2233 	 */
2234 
2235 	next_config_rom =
2236 		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2237 				   &next_config_rom_bus, GFP_KERNEL);
2238 	if (next_config_rom == NULL)
2239 		return -ENOMEM;
2240 
2241 	spin_lock_irqsave(&ohci->lock, flags);
2242 
2243 	if (ohci->next_config_rom == NULL) {
2244 		ohci->next_config_rom = next_config_rom;
2245 		ohci->next_config_rom_bus = next_config_rom_bus;
2246 
2247 		copy_config_rom(ohci->next_config_rom, config_rom, length);
2248 
2249 		ohci->next_header = config_rom[0];
2250 		ohci->next_config_rom[0] = 0;
2251 
2252 		reg_write(ohci, OHCI1394_ConfigROMmap,
2253 			  ohci->next_config_rom_bus);
2254 		ret = 0;
2255 	}
2256 
2257 	spin_unlock_irqrestore(&ohci->lock, flags);
2258 
2259 	/*
2260 	 * Now initiate a bus reset to have the changes take
2261 	 * effect. We clean up the old config rom memory and DMA
2262 	 * mappings in the bus reset tasklet, since the OHCI
2263 	 * controller could need to access it before the bus reset
2264 	 * takes effect.
2265 	 */
2266 	if (ret == 0)
2267 		fw_schedule_bus_reset(&ohci->card, true, true);
2268 	else
2269 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
2270 				  next_config_rom, next_config_rom_bus);
2271 
2272 	return ret;
2273 }
2274 
2275 static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
2276 {
2277 	struct fw_ohci *ohci = fw_ohci(card);
2278 
2279 	at_context_transmit(&ohci->at_request_ctx, packet);
2280 }
2281 
2282 static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
2283 {
2284 	struct fw_ohci *ohci = fw_ohci(card);
2285 
2286 	at_context_transmit(&ohci->at_response_ctx, packet);
2287 }
2288 
2289 static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
2290 {
2291 	struct fw_ohci *ohci = fw_ohci(card);
2292 	struct context *ctx = &ohci->at_request_ctx;
2293 	struct driver_data *driver_data = packet->driver_data;
2294 	int ret = -ENOENT;
2295 
2296 	tasklet_disable(&ctx->tasklet);
2297 
2298 	if (packet->ack != 0)
2299 		goto out;
2300 
2301 	if (packet->payload_mapped)
2302 		dma_unmap_single(ohci->card.device, packet->payload_bus,
2303 				 packet->payload_length, DMA_TO_DEVICE);
2304 
2305 	log_ar_at_event('T', packet->speed, packet->header, 0x20);
2306 	driver_data->packet = NULL;
2307 	packet->ack = RCODE_CANCELLED;
2308 	packet->callback(packet, &ohci->card, packet->ack);
2309 	ret = 0;
2310  out:
2311 	tasklet_enable(&ctx->tasklet);
2312 
2313 	return ret;
2314 }
2315 
2316 static int ohci_enable_phys_dma(struct fw_card *card,
2317 				int node_id, int generation)
2318 {
2319 #ifdef CONFIG_FIREWIRE_OHCI_REMOTE_DMA
2320 	return 0;
2321 #else
2322 	struct fw_ohci *ohci = fw_ohci(card);
2323 	unsigned long flags;
2324 	int n, ret = 0;
2325 
2326 	/*
2327 	 * FIXME:  Make sure this bitmask is cleared when we clear the busReset
2328 	 * interrupt bit.  Clear physReqResourceAllBuses on bus reset.
2329 	 */
2330 
2331 	spin_lock_irqsave(&ohci->lock, flags);
2332 
2333 	if (ohci->generation != generation) {
2334 		ret = -ESTALE;
2335 		goto out;
2336 	}
2337 
2338 	/*
2339 	 * Note, if the node ID contains a non-local bus ID, physical DMA is
2340 	 * enabled for _all_ nodes on remote buses.
2341 	 */
2342 
2343 	n = (node_id & 0xffc0) == LOCAL_BUS ? node_id & 0x3f : 63;
2344 	if (n < 32)
2345 		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << n);
2346 	else
2347 		reg_write(ohci, OHCI1394_PhyReqFilterHiSet, 1 << (n - 32));
2348 
2349 	flush_writes(ohci);
2350  out:
2351 	spin_unlock_irqrestore(&ohci->lock, flags);
2352 
2353 	return ret;
2354 #endif /* CONFIG_FIREWIRE_OHCI_REMOTE_DMA */
2355 }
2356 
2357 static u32 ohci_read_csr(struct fw_card *card, int csr_offset)
2358 {
2359 	struct fw_ohci *ohci = fw_ohci(card);
2360 	unsigned long flags;
2361 	u32 value;
2362 
2363 	switch (csr_offset) {
2364 	case CSR_STATE_CLEAR:
2365 	case CSR_STATE_SET:
2366 		if (ohci->is_root &&
2367 		    (reg_read(ohci, OHCI1394_LinkControlSet) &
2368 		     OHCI1394_LinkControl_cycleMaster))
2369 			value = CSR_STATE_BIT_CMSTR;
2370 		else
2371 			value = 0;
2372 		if (ohci->csr_state_setclear_abdicate)
2373 			value |= CSR_STATE_BIT_ABDICATE;
2374 
2375 		return value;
2376 
2377 	case CSR_NODE_IDS:
2378 		return reg_read(ohci, OHCI1394_NodeID) << 16;
2379 
2380 	case CSR_CYCLE_TIME:
2381 		return get_cycle_time(ohci);
2382 
2383 	case CSR_BUS_TIME:
2384 		/*
2385 		 * We might be called just after the cycle timer has wrapped
2386 		 * around but just before the cycle64Seconds handler, so we
2387 		 * better check here, too, if the bus time needs to be updated.
2388 		 */
2389 		spin_lock_irqsave(&ohci->lock, flags);
2390 		value = update_bus_time(ohci);
2391 		spin_unlock_irqrestore(&ohci->lock, flags);
2392 		return value;
2393 
2394 	case CSR_BUSY_TIMEOUT:
2395 		value = reg_read(ohci, OHCI1394_ATRetries);
2396 		return (value >> 4) & 0x0ffff00f;
2397 
2398 	case CSR_PRIORITY_BUDGET:
2399 		return (reg_read(ohci, OHCI1394_FairnessControl) & 0x3f) |
2400 			(ohci->pri_req_max << 8);
2401 
2402 	default:
2403 		WARN_ON(1);
2404 		return 0;
2405 	}
2406 }
2407 
2408 static void ohci_write_csr(struct fw_card *card, int csr_offset, u32 value)
2409 {
2410 	struct fw_ohci *ohci = fw_ohci(card);
2411 	unsigned long flags;
2412 
2413 	switch (csr_offset) {
2414 	case CSR_STATE_CLEAR:
2415 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2416 			reg_write(ohci, OHCI1394_LinkControlClear,
2417 				  OHCI1394_LinkControl_cycleMaster);
2418 			flush_writes(ohci);
2419 		}
2420 		if (value & CSR_STATE_BIT_ABDICATE)
2421 			ohci->csr_state_setclear_abdicate = false;
2422 		break;
2423 
2424 	case CSR_STATE_SET:
2425 		if ((value & CSR_STATE_BIT_CMSTR) && ohci->is_root) {
2426 			reg_write(ohci, OHCI1394_LinkControlSet,
2427 				  OHCI1394_LinkControl_cycleMaster);
2428 			flush_writes(ohci);
2429 		}
2430 		if (value & CSR_STATE_BIT_ABDICATE)
2431 			ohci->csr_state_setclear_abdicate = true;
2432 		break;
2433 
2434 	case CSR_NODE_IDS:
2435 		reg_write(ohci, OHCI1394_NodeID, value >> 16);
2436 		flush_writes(ohci);
2437 		break;
2438 
2439 	case CSR_CYCLE_TIME:
2440 		reg_write(ohci, OHCI1394_IsochronousCycleTimer, value);
2441 		reg_write(ohci, OHCI1394_IntEventSet,
2442 			  OHCI1394_cycleInconsistent);
2443 		flush_writes(ohci);
2444 		break;
2445 
2446 	case CSR_BUS_TIME:
2447 		spin_lock_irqsave(&ohci->lock, flags);
2448 		ohci->bus_time = (ohci->bus_time & 0x7f) | (value & ~0x7f);
2449 		spin_unlock_irqrestore(&ohci->lock, flags);
2450 		break;
2451 
2452 	case CSR_BUSY_TIMEOUT:
2453 		value = (value & 0xf) | ((value & 0xf) << 4) |
2454 			((value & 0xf) << 8) | ((value & 0x0ffff000) << 4);
2455 		reg_write(ohci, OHCI1394_ATRetries, value);
2456 		flush_writes(ohci);
2457 		break;
2458 
2459 	case CSR_PRIORITY_BUDGET:
2460 		reg_write(ohci, OHCI1394_FairnessControl, value & 0x3f);
2461 		flush_writes(ohci);
2462 		break;
2463 
2464 	default:
2465 		WARN_ON(1);
2466 		break;
2467 	}
2468 }
2469 
2470 static void copy_iso_headers(struct iso_context *ctx, void *p)
2471 {
2472 	int i = ctx->header_length;
2473 
2474 	if (i + ctx->base.header_size > PAGE_SIZE)
2475 		return;
2476 
2477 	/*
2478 	 * The iso header is byteswapped to little endian by
2479 	 * the controller, but the remaining header quadlets
2480 	 * are big endian.  We want to present all the headers
2481 	 * as big endian, so we have to swap the first quadlet.
2482 	 */
2483 	if (ctx->base.header_size > 0)
2484 		*(u32 *) (ctx->header + i) = __swab32(*(u32 *) (p + 4));
2485 	if (ctx->base.header_size > 4)
2486 		*(u32 *) (ctx->header + i + 4) = __swab32(*(u32 *) p);
2487 	if (ctx->base.header_size > 8)
2488 		memcpy(ctx->header + i + 8, p + 8, ctx->base.header_size - 8);
2489 	ctx->header_length += ctx->base.header_size;
2490 }
2491 
2492 static int handle_ir_packet_per_buffer(struct context *context,
2493 				       struct descriptor *d,
2494 				       struct descriptor *last)
2495 {
2496 	struct iso_context *ctx =
2497 		container_of(context, struct iso_context, context);
2498 	struct descriptor *pd;
2499 	__le32 *ir_header;
2500 	void *p;
2501 
2502 	for (pd = d; pd <= last; pd++)
2503 		if (pd->transfer_status)
2504 			break;
2505 	if (pd > last)
2506 		/* Descriptor(s) not done yet, stop iteration */
2507 		return 0;
2508 
2509 	p = last + 1;
2510 	copy_iso_headers(ctx, p);
2511 
2512 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
2513 		ir_header = (__le32 *) p;
2514 		ctx->base.callback.sc(&ctx->base,
2515 				      le32_to_cpu(ir_header[0]) & 0xffff,
2516 				      ctx->header_length, ctx->header,
2517 				      ctx->base.callback_data);
2518 		ctx->header_length = 0;
2519 	}
2520 
2521 	return 1;
2522 }
2523 
2524 /* d == last because each descriptor block is only a single descriptor. */
2525 static int handle_ir_buffer_fill(struct context *context,
2526 				 struct descriptor *d,
2527 				 struct descriptor *last)
2528 {
2529 	struct iso_context *ctx =
2530 		container_of(context, struct iso_context, context);
2531 
2532 	if (!last->transfer_status)
2533 		/* Descriptor(s) not done yet, stop iteration */
2534 		return 0;
2535 
2536 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS)
2537 		ctx->base.callback.mc(&ctx->base,
2538 				      le32_to_cpu(last->data_address) +
2539 				      le16_to_cpu(last->req_count) -
2540 				      le16_to_cpu(last->res_count),
2541 				      ctx->base.callback_data);
2542 
2543 	return 1;
2544 }
2545 
2546 static int handle_it_packet(struct context *context,
2547 			    struct descriptor *d,
2548 			    struct descriptor *last)
2549 {
2550 	struct iso_context *ctx =
2551 		container_of(context, struct iso_context, context);
2552 	int i;
2553 	struct descriptor *pd;
2554 
2555 	for (pd = d; pd <= last; pd++)
2556 		if (pd->transfer_status)
2557 			break;
2558 	if (pd > last)
2559 		/* Descriptor(s) not done yet, stop iteration */
2560 		return 0;
2561 
2562 	i = ctx->header_length;
2563 	if (i + 4 < PAGE_SIZE) {
2564 		/* Present this value as big-endian to match the receive code */
2565 		*(__be32 *)(ctx->header + i) = cpu_to_be32(
2566 				((u32)le16_to_cpu(pd->transfer_status) << 16) |
2567 				le16_to_cpu(pd->res_count));
2568 		ctx->header_length += 4;
2569 	}
2570 	if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
2571 		ctx->base.callback.sc(&ctx->base, le16_to_cpu(last->res_count),
2572 				      ctx->header_length, ctx->header,
2573 				      ctx->base.callback_data);
2574 		ctx->header_length = 0;
2575 	}
2576 	return 1;
2577 }
2578 
2579 static void set_multichannel_mask(struct fw_ohci *ohci, u64 channels)
2580 {
2581 	u32 hi = channels >> 32, lo = channels;
2582 
2583 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiClear, ~hi);
2584 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoClear, ~lo);
2585 	reg_write(ohci, OHCI1394_IRMultiChanMaskHiSet, hi);
2586 	reg_write(ohci, OHCI1394_IRMultiChanMaskLoSet, lo);
2587 	mmiowb();
2588 	ohci->mc_channels = channels;
2589 }
2590 
2591 static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
2592 				int type, int channel, size_t header_size)
2593 {
2594 	struct fw_ohci *ohci = fw_ohci(card);
2595 	struct iso_context *uninitialized_var(ctx);
2596 	descriptor_callback_t uninitialized_var(callback);
2597 	u64 *uninitialized_var(channels);
2598 	u32 *uninitialized_var(mask), uninitialized_var(regs);
2599 	unsigned long flags;
2600 	int index, ret = -EBUSY;
2601 
2602 	spin_lock_irqsave(&ohci->lock, flags);
2603 
2604 	switch (type) {
2605 	case FW_ISO_CONTEXT_TRANSMIT:
2606 		mask     = &ohci->it_context_mask;
2607 		callback = handle_it_packet;
2608 		index    = ffs(*mask) - 1;
2609 		if (index >= 0) {
2610 			*mask &= ~(1 << index);
2611 			regs = OHCI1394_IsoXmitContextBase(index);
2612 			ctx  = &ohci->it_context_list[index];
2613 		}
2614 		break;
2615 
2616 	case FW_ISO_CONTEXT_RECEIVE:
2617 		channels = &ohci->ir_context_channels;
2618 		mask     = &ohci->ir_context_mask;
2619 		callback = handle_ir_packet_per_buffer;
2620 		index    = *channels & 1ULL << channel ? ffs(*mask) - 1 : -1;
2621 		if (index >= 0) {
2622 			*channels &= ~(1ULL << channel);
2623 			*mask     &= ~(1 << index);
2624 			regs = OHCI1394_IsoRcvContextBase(index);
2625 			ctx  = &ohci->ir_context_list[index];
2626 		}
2627 		break;
2628 
2629 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2630 		mask     = &ohci->ir_context_mask;
2631 		callback = handle_ir_buffer_fill;
2632 		index    = !ohci->mc_allocated ? ffs(*mask) - 1 : -1;
2633 		if (index >= 0) {
2634 			ohci->mc_allocated = true;
2635 			*mask &= ~(1 << index);
2636 			regs = OHCI1394_IsoRcvContextBase(index);
2637 			ctx  = &ohci->ir_context_list[index];
2638 		}
2639 		break;
2640 
2641 	default:
2642 		index = -1;
2643 		ret = -ENOSYS;
2644 	}
2645 
2646 	spin_unlock_irqrestore(&ohci->lock, flags);
2647 
2648 	if (index < 0)
2649 		return ERR_PTR(ret);
2650 
2651 	memset(ctx, 0, sizeof(*ctx));
2652 	ctx->header_length = 0;
2653 	ctx->header = (void *) __get_free_page(GFP_KERNEL);
2654 	if (ctx->header == NULL) {
2655 		ret = -ENOMEM;
2656 		goto out;
2657 	}
2658 	ret = context_init(&ctx->context, ohci, regs, callback);
2659 	if (ret < 0)
2660 		goto out_with_header;
2661 
2662 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL)
2663 		set_multichannel_mask(ohci, 0);
2664 
2665 	return &ctx->base;
2666 
2667  out_with_header:
2668 	free_page((unsigned long)ctx->header);
2669  out:
2670 	spin_lock_irqsave(&ohci->lock, flags);
2671 
2672 	switch (type) {
2673 	case FW_ISO_CONTEXT_RECEIVE:
2674 		*channels |= 1ULL << channel;
2675 		break;
2676 
2677 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2678 		ohci->mc_allocated = false;
2679 		break;
2680 	}
2681 	*mask |= 1 << index;
2682 
2683 	spin_unlock_irqrestore(&ohci->lock, flags);
2684 
2685 	return ERR_PTR(ret);
2686 }
2687 
2688 static int ohci_start_iso(struct fw_iso_context *base,
2689 			  s32 cycle, u32 sync, u32 tags)
2690 {
2691 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2692 	struct fw_ohci *ohci = ctx->context.ohci;
2693 	u32 control = IR_CONTEXT_ISOCH_HEADER, match;
2694 	int index;
2695 
2696 	/* the controller cannot start without any queued packets */
2697 	if (ctx->context.last->branch_address == 0)
2698 		return -ENODATA;
2699 
2700 	switch (ctx->base.type) {
2701 	case FW_ISO_CONTEXT_TRANSMIT:
2702 		index = ctx - ohci->it_context_list;
2703 		match = 0;
2704 		if (cycle >= 0)
2705 			match = IT_CONTEXT_CYCLE_MATCH_ENABLE |
2706 				(cycle & 0x7fff) << 16;
2707 
2708 		reg_write(ohci, OHCI1394_IsoXmitIntEventClear, 1 << index);
2709 		reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
2710 		context_run(&ctx->context, match);
2711 		break;
2712 
2713 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2714 		control |= IR_CONTEXT_BUFFER_FILL|IR_CONTEXT_MULTI_CHANNEL_MODE;
2715 		/* fall through */
2716 	case FW_ISO_CONTEXT_RECEIVE:
2717 		index = ctx - ohci->ir_context_list;
2718 		match = (tags << 28) | (sync << 8) | ctx->base.channel;
2719 		if (cycle >= 0) {
2720 			match |= (cycle & 0x07fff) << 12;
2721 			control |= IR_CONTEXT_CYCLE_MATCH_ENABLE;
2722 		}
2723 
2724 		reg_write(ohci, OHCI1394_IsoRecvIntEventClear, 1 << index);
2725 		reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, 1 << index);
2726 		reg_write(ohci, CONTEXT_MATCH(ctx->context.regs), match);
2727 		context_run(&ctx->context, control);
2728 
2729 		ctx->sync = sync;
2730 		ctx->tags = tags;
2731 
2732 		break;
2733 	}
2734 
2735 	return 0;
2736 }
2737 
2738 static int ohci_stop_iso(struct fw_iso_context *base)
2739 {
2740 	struct fw_ohci *ohci = fw_ohci(base->card);
2741 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2742 	int index;
2743 
2744 	switch (ctx->base.type) {
2745 	case FW_ISO_CONTEXT_TRANSMIT:
2746 		index = ctx - ohci->it_context_list;
2747 		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
2748 		break;
2749 
2750 	case FW_ISO_CONTEXT_RECEIVE:
2751 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2752 		index = ctx - ohci->ir_context_list;
2753 		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
2754 		break;
2755 	}
2756 	flush_writes(ohci);
2757 	context_stop(&ctx->context);
2758 	tasklet_kill(&ctx->context.tasklet);
2759 
2760 	return 0;
2761 }
2762 
2763 static void ohci_free_iso_context(struct fw_iso_context *base)
2764 {
2765 	struct fw_ohci *ohci = fw_ohci(base->card);
2766 	struct iso_context *ctx = container_of(base, struct iso_context, base);
2767 	unsigned long flags;
2768 	int index;
2769 
2770 	ohci_stop_iso(base);
2771 	context_release(&ctx->context);
2772 	free_page((unsigned long)ctx->header);
2773 
2774 	spin_lock_irqsave(&ohci->lock, flags);
2775 
2776 	switch (base->type) {
2777 	case FW_ISO_CONTEXT_TRANSMIT:
2778 		index = ctx - ohci->it_context_list;
2779 		ohci->it_context_mask |= 1 << index;
2780 		break;
2781 
2782 	case FW_ISO_CONTEXT_RECEIVE:
2783 		index = ctx - ohci->ir_context_list;
2784 		ohci->ir_context_mask |= 1 << index;
2785 		ohci->ir_context_channels |= 1ULL << base->channel;
2786 		break;
2787 
2788 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2789 		index = ctx - ohci->ir_context_list;
2790 		ohci->ir_context_mask |= 1 << index;
2791 		ohci->ir_context_channels |= ohci->mc_channels;
2792 		ohci->mc_channels = 0;
2793 		ohci->mc_allocated = false;
2794 		break;
2795 	}
2796 
2797 	spin_unlock_irqrestore(&ohci->lock, flags);
2798 }
2799 
2800 static int ohci_set_iso_channels(struct fw_iso_context *base, u64 *channels)
2801 {
2802 	struct fw_ohci *ohci = fw_ohci(base->card);
2803 	unsigned long flags;
2804 	int ret;
2805 
2806 	switch (base->type) {
2807 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
2808 
2809 		spin_lock_irqsave(&ohci->lock, flags);
2810 
2811 		/* Don't allow multichannel to grab other contexts' channels. */
2812 		if (~ohci->ir_context_channels & ~ohci->mc_channels & *channels) {
2813 			*channels = ohci->ir_context_channels;
2814 			ret = -EBUSY;
2815 		} else {
2816 			set_multichannel_mask(ohci, *channels);
2817 			ret = 0;
2818 		}
2819 
2820 		spin_unlock_irqrestore(&ohci->lock, flags);
2821 
2822 		break;
2823 	default:
2824 		ret = -EINVAL;
2825 	}
2826 
2827 	return ret;
2828 }
2829 
2830 #ifdef CONFIG_PM
2831 static void ohci_resume_iso_dma(struct fw_ohci *ohci)
2832 {
2833 	int i;
2834 	struct iso_context *ctx;
2835 
2836 	for (i = 0 ; i < ohci->n_ir ; i++) {
2837 		ctx = &ohci->ir_context_list[i];
2838 		if (ctx->context.running)
2839 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
2840 	}
2841 
2842 	for (i = 0 ; i < ohci->n_it ; i++) {
2843 		ctx = &ohci->it_context_list[i];
2844 		if (ctx->context.running)
2845 			ohci_start_iso(&ctx->base, 0, ctx->sync, ctx->tags);
2846 	}
2847 }
2848 #endif
2849 
2850 static int queue_iso_transmit(struct iso_context *ctx,
2851 			      struct fw_iso_packet *packet,
2852 			      struct fw_iso_buffer *buffer,
2853 			      unsigned long payload)
2854 {
2855 	struct descriptor *d, *last, *pd;
2856 	struct fw_iso_packet *p;
2857 	__le32 *header;
2858 	dma_addr_t d_bus, page_bus;
2859 	u32 z, header_z, payload_z, irq;
2860 	u32 payload_index, payload_end_index, next_page_index;
2861 	int page, end_page, i, length, offset;
2862 
2863 	p = packet;
2864 	payload_index = payload;
2865 
2866 	if (p->skip)
2867 		z = 1;
2868 	else
2869 		z = 2;
2870 	if (p->header_length > 0)
2871 		z++;
2872 
2873 	/* Determine the first page the payload isn't contained in. */
2874 	end_page = PAGE_ALIGN(payload_index + p->payload_length) >> PAGE_SHIFT;
2875 	if (p->payload_length > 0)
2876 		payload_z = end_page - (payload_index >> PAGE_SHIFT);
2877 	else
2878 		payload_z = 0;
2879 
2880 	z += payload_z;
2881 
2882 	/* Get header size in number of descriptors. */
2883 	header_z = DIV_ROUND_UP(p->header_length, sizeof(*d));
2884 
2885 	d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
2886 	if (d == NULL)
2887 		return -ENOMEM;
2888 
2889 	if (!p->skip) {
2890 		d[0].control   = cpu_to_le16(DESCRIPTOR_KEY_IMMEDIATE);
2891 		d[0].req_count = cpu_to_le16(8);
2892 		/*
2893 		 * Link the skip address to this descriptor itself.  This causes
2894 		 * a context to skip a cycle whenever lost cycles or FIFO
2895 		 * overruns occur, without dropping the data.  The application
2896 		 * should then decide whether this is an error condition or not.
2897 		 * FIXME:  Make the context's cycle-lost behaviour configurable?
2898 		 */
2899 		d[0].branch_address = cpu_to_le32(d_bus | z);
2900 
2901 		header = (__le32 *) &d[1];
2902 		header[0] = cpu_to_le32(IT_HEADER_SY(p->sy) |
2903 					IT_HEADER_TAG(p->tag) |
2904 					IT_HEADER_TCODE(TCODE_STREAM_DATA) |
2905 					IT_HEADER_CHANNEL(ctx->base.channel) |
2906 					IT_HEADER_SPEED(ctx->base.speed));
2907 		header[1] =
2908 			cpu_to_le32(IT_HEADER_DATA_LENGTH(p->header_length +
2909 							  p->payload_length));
2910 	}
2911 
2912 	if (p->header_length > 0) {
2913 		d[2].req_count    = cpu_to_le16(p->header_length);
2914 		d[2].data_address = cpu_to_le32(d_bus + z * sizeof(*d));
2915 		memcpy(&d[z], p->header, p->header_length);
2916 	}
2917 
2918 	pd = d + z - payload_z;
2919 	payload_end_index = payload_index + p->payload_length;
2920 	for (i = 0; i < payload_z; i++) {
2921 		page               = payload_index >> PAGE_SHIFT;
2922 		offset             = payload_index & ~PAGE_MASK;
2923 		next_page_index    = (page + 1) << PAGE_SHIFT;
2924 		length             =
2925 			min(next_page_index, payload_end_index) - payload_index;
2926 		pd[i].req_count    = cpu_to_le16(length);
2927 
2928 		page_bus = page_private(buffer->pages[page]);
2929 		pd[i].data_address = cpu_to_le32(page_bus + offset);
2930 
2931 		payload_index += length;
2932 	}
2933 
2934 	if (p->interrupt)
2935 		irq = DESCRIPTOR_IRQ_ALWAYS;
2936 	else
2937 		irq = DESCRIPTOR_NO_IRQ;
2938 
2939 	last = z == 2 ? d : d + z - 1;
2940 	last->control |= cpu_to_le16(DESCRIPTOR_OUTPUT_LAST |
2941 				     DESCRIPTOR_STATUS |
2942 				     DESCRIPTOR_BRANCH_ALWAYS |
2943 				     irq);
2944 
2945 	context_append(&ctx->context, d, z, header_z);
2946 
2947 	return 0;
2948 }
2949 
2950 static int queue_iso_packet_per_buffer(struct iso_context *ctx,
2951 				       struct fw_iso_packet *packet,
2952 				       struct fw_iso_buffer *buffer,
2953 				       unsigned long payload)
2954 {
2955 	struct descriptor *d, *pd;
2956 	dma_addr_t d_bus, page_bus;
2957 	u32 z, header_z, rest;
2958 	int i, j, length;
2959 	int page, offset, packet_count, header_size, payload_per_buffer;
2960 
2961 	/*
2962 	 * The OHCI controller puts the isochronous header and trailer in the
2963 	 * buffer, so we need at least 8 bytes.
2964 	 */
2965 	packet_count = packet->header_length / ctx->base.header_size;
2966 	header_size  = max(ctx->base.header_size, (size_t)8);
2967 
2968 	/* Get header size in number of descriptors. */
2969 	header_z = DIV_ROUND_UP(header_size, sizeof(*d));
2970 	page     = payload >> PAGE_SHIFT;
2971 	offset   = payload & ~PAGE_MASK;
2972 	payload_per_buffer = packet->payload_length / packet_count;
2973 
2974 	for (i = 0; i < packet_count; i++) {
2975 		/* d points to the header descriptor */
2976 		z = DIV_ROUND_UP(payload_per_buffer + offset, PAGE_SIZE) + 1;
2977 		d = context_get_descriptors(&ctx->context,
2978 				z + header_z, &d_bus);
2979 		if (d == NULL)
2980 			return -ENOMEM;
2981 
2982 		d->control      = cpu_to_le16(DESCRIPTOR_STATUS |
2983 					      DESCRIPTOR_INPUT_MORE);
2984 		if (packet->skip && i == 0)
2985 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
2986 		d->req_count    = cpu_to_le16(header_size);
2987 		d->res_count    = d->req_count;
2988 		d->transfer_status = 0;
2989 		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));
2990 
2991 		rest = payload_per_buffer;
2992 		pd = d;
2993 		for (j = 1; j < z; j++) {
2994 			pd++;
2995 			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
2996 						  DESCRIPTOR_INPUT_MORE);
2997 
2998 			if (offset + rest < PAGE_SIZE)
2999 				length = rest;
3000 			else
3001 				length = PAGE_SIZE - offset;
3002 			pd->req_count = cpu_to_le16(length);
3003 			pd->res_count = pd->req_count;
3004 			pd->transfer_status = 0;
3005 
3006 			page_bus = page_private(buffer->pages[page]);
3007 			pd->data_address = cpu_to_le32(page_bus + offset);
3008 
3009 			offset = (offset + length) & ~PAGE_MASK;
3010 			rest -= length;
3011 			if (offset == 0)
3012 				page++;
3013 		}
3014 		pd->control = cpu_to_le16(DESCRIPTOR_STATUS |
3015 					  DESCRIPTOR_INPUT_LAST |
3016 					  DESCRIPTOR_BRANCH_ALWAYS);
3017 		if (packet->interrupt && i == packet_count - 1)
3018 			pd->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3019 
3020 		context_append(&ctx->context, d, z, header_z);
3021 	}
3022 
3023 	return 0;
3024 }
3025 
3026 static int queue_iso_buffer_fill(struct iso_context *ctx,
3027 				 struct fw_iso_packet *packet,
3028 				 struct fw_iso_buffer *buffer,
3029 				 unsigned long payload)
3030 {
3031 	struct descriptor *d;
3032 	dma_addr_t d_bus, page_bus;
3033 	int page, offset, rest, z, i, length;
3034 
3035 	page   = payload >> PAGE_SHIFT;
3036 	offset = payload & ~PAGE_MASK;
3037 	rest   = packet->payload_length;
3038 
3039 	/* We need one descriptor for each page in the buffer. */
3040 	z = DIV_ROUND_UP(offset + rest, PAGE_SIZE);
3041 
3042 	if (WARN_ON(offset & 3 || rest & 3 || page + z > buffer->page_count))
3043 		return -EFAULT;
3044 
3045 	for (i = 0; i < z; i++) {
3046 		d = context_get_descriptors(&ctx->context, 1, &d_bus);
3047 		if (d == NULL)
3048 			return -ENOMEM;
3049 
3050 		d->control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
3051 					 DESCRIPTOR_BRANCH_ALWAYS);
3052 		if (packet->skip && i == 0)
3053 			d->control |= cpu_to_le16(DESCRIPTOR_WAIT);
3054 		if (packet->interrupt && i == z - 1)
3055 			d->control |= cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS);
3056 
3057 		if (offset + rest < PAGE_SIZE)
3058 			length = rest;
3059 		else
3060 			length = PAGE_SIZE - offset;
3061 		d->req_count = cpu_to_le16(length);
3062 		d->res_count = d->req_count;
3063 		d->transfer_status = 0;
3064 
3065 		page_bus = page_private(buffer->pages[page]);
3066 		d->data_address = cpu_to_le32(page_bus + offset);
3067 
3068 		rest -= length;
3069 		offset = 0;
3070 		page++;
3071 
3072 		context_append(&ctx->context, d, 1, 0);
3073 	}
3074 
3075 	return 0;
3076 }
3077 
3078 static int ohci_queue_iso(struct fw_iso_context *base,
3079 			  struct fw_iso_packet *packet,
3080 			  struct fw_iso_buffer *buffer,
3081 			  unsigned long payload)
3082 {
3083 	struct iso_context *ctx = container_of(base, struct iso_context, base);
3084 	unsigned long flags;
3085 	int ret = -ENOSYS;
3086 
3087 	spin_lock_irqsave(&ctx->context.ohci->lock, flags);
3088 	switch (base->type) {
3089 	case FW_ISO_CONTEXT_TRANSMIT:
3090 		ret = queue_iso_transmit(ctx, packet, buffer, payload);
3091 		break;
3092 	case FW_ISO_CONTEXT_RECEIVE:
3093 		ret = queue_iso_packet_per_buffer(ctx, packet, buffer, payload);
3094 		break;
3095 	case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL:
3096 		ret = queue_iso_buffer_fill(ctx, packet, buffer, payload);
3097 		break;
3098 	}
3099 	spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
3100 
3101 	return ret;
3102 }
3103 
3104 static const struct fw_card_driver ohci_driver = {
3105 	.enable			= ohci_enable,
3106 	.read_phy_reg		= ohci_read_phy_reg,
3107 	.update_phy_reg		= ohci_update_phy_reg,
3108 	.set_config_rom		= ohci_set_config_rom,
3109 	.send_request		= ohci_send_request,
3110 	.send_response		= ohci_send_response,
3111 	.cancel_packet		= ohci_cancel_packet,
3112 	.enable_phys_dma	= ohci_enable_phys_dma,
3113 	.read_csr		= ohci_read_csr,
3114 	.write_csr		= ohci_write_csr,
3115 
3116 	.allocate_iso_context	= ohci_allocate_iso_context,
3117 	.free_iso_context	= ohci_free_iso_context,
3118 	.set_iso_channels	= ohci_set_iso_channels,
3119 	.queue_iso		= ohci_queue_iso,
3120 	.start_iso		= ohci_start_iso,
3121 	.stop_iso		= ohci_stop_iso,
3122 };
3123 
3124 #ifdef CONFIG_PPC_PMAC
3125 static void pmac_ohci_on(struct pci_dev *dev)
3126 {
3127 	if (machine_is(powermac)) {
3128 		struct device_node *ofn = pci_device_to_OF_node(dev);
3129 
3130 		if (ofn) {
3131 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 1);
3132 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 1);
3133 		}
3134 	}
3135 }
3136 
3137 static void pmac_ohci_off(struct pci_dev *dev)
3138 {
3139 	if (machine_is(powermac)) {
3140 		struct device_node *ofn = pci_device_to_OF_node(dev);
3141 
3142 		if (ofn) {
3143 			pmac_call_feature(PMAC_FTR_1394_ENABLE, ofn, 0, 0);
3144 			pmac_call_feature(PMAC_FTR_1394_CABLE_POWER, ofn, 0, 0);
3145 		}
3146 	}
3147 }
3148 #else
3149 static inline void pmac_ohci_on(struct pci_dev *dev) {}
3150 static inline void pmac_ohci_off(struct pci_dev *dev) {}
3151 #endif /* CONFIG_PPC_PMAC */
3152 
3153 static int __devinit pci_probe(struct pci_dev *dev,
3154 			       const struct pci_device_id *ent)
3155 {
3156 	struct fw_ohci *ohci;
3157 	u32 bus_options, max_receive, link_speed, version;
3158 	u64 guid;
3159 	int i, err;
3160 	size_t size;
3161 
3162 	ohci = kzalloc(sizeof(*ohci), GFP_KERNEL);
3163 	if (ohci == NULL) {
3164 		err = -ENOMEM;
3165 		goto fail;
3166 	}
3167 
3168 	fw_card_initialize(&ohci->card, &ohci_driver, &dev->dev);
3169 
3170 	pmac_ohci_on(dev);
3171 
3172 	err = pci_enable_device(dev);
3173 	if (err) {
3174 		fw_error("Failed to enable OHCI hardware\n");
3175 		goto fail_free;
3176 	}
3177 
3178 	pci_set_master(dev);
3179 	pci_write_config_dword(dev, OHCI1394_PCI_HCI_Control, 0);
3180 	pci_set_drvdata(dev, ohci);
3181 
3182 	spin_lock_init(&ohci->lock);
3183 	mutex_init(&ohci->phy_reg_mutex);
3184 
3185 	tasklet_init(&ohci->bus_reset_tasklet,
3186 		     bus_reset_tasklet, (unsigned long)ohci);
3187 
3188 	err = pci_request_region(dev, 0, ohci_driver_name);
3189 	if (err) {
3190 		fw_error("MMIO resource unavailable\n");
3191 		goto fail_disable;
3192 	}
3193 
3194 	ohci->registers = pci_iomap(dev, 0, OHCI1394_REGISTER_SIZE);
3195 	if (ohci->registers == NULL) {
3196 		fw_error("Failed to remap registers\n");
3197 		err = -ENXIO;
3198 		goto fail_iomem;
3199 	}
3200 
3201 	for (i = 0; i < ARRAY_SIZE(ohci_quirks); i++)
3202 		if ((ohci_quirks[i].vendor == dev->vendor) &&
3203 		    (ohci_quirks[i].device == (unsigned short)PCI_ANY_ID ||
3204 		     ohci_quirks[i].device == dev->device) &&
3205 		    (ohci_quirks[i].revision == (unsigned short)PCI_ANY_ID ||
3206 		     ohci_quirks[i].revision >= dev->revision)) {
3207 			ohci->quirks = ohci_quirks[i].flags;
3208 			break;
3209 		}
3210 	if (param_quirks)
3211 		ohci->quirks = param_quirks;
3212 
3213 	/*
3214 	 * Because dma_alloc_coherent() allocates at least one page,
3215 	 * we save space by using a common buffer for the AR request/
3216 	 * response descriptors and the self IDs buffer.
3217 	 */
3218 	BUILD_BUG_ON(AR_BUFFERS * sizeof(struct descriptor) > PAGE_SIZE/4);
3219 	BUILD_BUG_ON(SELF_ID_BUF_SIZE > PAGE_SIZE/2);
3220 	ohci->misc_buffer = dma_alloc_coherent(ohci->card.device,
3221 					       PAGE_SIZE,
3222 					       &ohci->misc_buffer_bus,
3223 					       GFP_KERNEL);
3224 	if (!ohci->misc_buffer) {
3225 		err = -ENOMEM;
3226 		goto fail_iounmap;
3227 	}
3228 
3229 	err = ar_context_init(&ohci->ar_request_ctx, ohci, 0,
3230 			      OHCI1394_AsReqRcvContextControlSet);
3231 	if (err < 0)
3232 		goto fail_misc_buf;
3233 
3234 	err = ar_context_init(&ohci->ar_response_ctx, ohci, PAGE_SIZE/4,
3235 			      OHCI1394_AsRspRcvContextControlSet);
3236 	if (err < 0)
3237 		goto fail_arreq_ctx;
3238 
3239 	err = context_init(&ohci->at_request_ctx, ohci,
3240 			   OHCI1394_AsReqTrContextControlSet, handle_at_packet);
3241 	if (err < 0)
3242 		goto fail_arrsp_ctx;
3243 
3244 	err = context_init(&ohci->at_response_ctx, ohci,
3245 			   OHCI1394_AsRspTrContextControlSet, handle_at_packet);
3246 	if (err < 0)
3247 		goto fail_atreq_ctx;
3248 
3249 	reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
3250 	ohci->ir_context_channels = ~0ULL;
3251 	ohci->ir_context_support = reg_read(ohci, OHCI1394_IsoRecvIntMaskSet);
3252 	reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, ~0);
3253 	ohci->ir_context_mask = ohci->ir_context_support;
3254 	ohci->n_ir = hweight32(ohci->ir_context_mask);
3255 	size = sizeof(struct iso_context) * ohci->n_ir;
3256 	ohci->ir_context_list = kzalloc(size, GFP_KERNEL);
3257 
3258 	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, ~0);
3259 	ohci->it_context_support = reg_read(ohci, OHCI1394_IsoXmitIntMaskSet);
3260 	reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, ~0);
3261 	ohci->it_context_mask = ohci->it_context_support;
3262 	ohci->n_it = hweight32(ohci->it_context_mask);
3263 	size = sizeof(struct iso_context) * ohci->n_it;
3264 	ohci->it_context_list = kzalloc(size, GFP_KERNEL);
3265 
3266 	if (ohci->it_context_list == NULL || ohci->ir_context_list == NULL) {
3267 		err = -ENOMEM;
3268 		goto fail_contexts;
3269 	}
3270 
3271 	ohci->self_id_cpu = ohci->misc_buffer     + PAGE_SIZE/2;
3272 	ohci->self_id_bus = ohci->misc_buffer_bus + PAGE_SIZE/2;
3273 
3274 	bus_options = reg_read(ohci, OHCI1394_BusOptions);
3275 	max_receive = (bus_options >> 12) & 0xf;
3276 	link_speed = bus_options & 0x7;
3277 	guid = ((u64) reg_read(ohci, OHCI1394_GUIDHi) << 32) |
3278 		reg_read(ohci, OHCI1394_GUIDLo);
3279 
3280 	err = fw_card_add(&ohci->card, max_receive, link_speed, guid);
3281 	if (err)
3282 		goto fail_contexts;
3283 
3284 	version = reg_read(ohci, OHCI1394_Version) & 0x00ff00ff;
3285 	fw_notify("Added fw-ohci device %s, OHCI v%x.%x, "
3286 		  "%d IR + %d IT contexts, quirks 0x%x\n",
3287 		  dev_name(&dev->dev), version >> 16, version & 0xff,
3288 		  ohci->n_ir, ohci->n_it, ohci->quirks);
3289 
3290 	return 0;
3291 
3292  fail_contexts:
3293 	kfree(ohci->ir_context_list);
3294 	kfree(ohci->it_context_list);
3295 	context_release(&ohci->at_response_ctx);
3296  fail_atreq_ctx:
3297 	context_release(&ohci->at_request_ctx);
3298  fail_arrsp_ctx:
3299 	ar_context_release(&ohci->ar_response_ctx);
3300  fail_arreq_ctx:
3301 	ar_context_release(&ohci->ar_request_ctx);
3302  fail_misc_buf:
3303 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3304 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3305  fail_iounmap:
3306 	pci_iounmap(dev, ohci->registers);
3307  fail_iomem:
3308 	pci_release_region(dev, 0);
3309  fail_disable:
3310 	pci_disable_device(dev);
3311  fail_free:
3312 	kfree(ohci);
3313 	pmac_ohci_off(dev);
3314  fail:
3315 	if (err == -ENOMEM)
3316 		fw_error("Out of memory\n");
3317 
3318 	return err;
3319 }
3320 
3321 static void pci_remove(struct pci_dev *dev)
3322 {
3323 	struct fw_ohci *ohci;
3324 
3325 	ohci = pci_get_drvdata(dev);
3326 	reg_write(ohci, OHCI1394_IntMaskClear, ~0);
3327 	flush_writes(ohci);
3328 	fw_core_remove_card(&ohci->card);
3329 
3330 	/*
3331 	 * FIXME: Fail all pending packets here, now that the upper
3332 	 * layers can't queue any more.
3333 	 */
3334 
3335 	software_reset(ohci);
3336 	free_irq(dev->irq, ohci);
3337 
3338 	if (ohci->next_config_rom && ohci->next_config_rom != ohci->config_rom)
3339 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3340 				  ohci->next_config_rom, ohci->next_config_rom_bus);
3341 	if (ohci->config_rom)
3342 		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
3343 				  ohci->config_rom, ohci->config_rom_bus);
3344 	ar_context_release(&ohci->ar_request_ctx);
3345 	ar_context_release(&ohci->ar_response_ctx);
3346 	dma_free_coherent(ohci->card.device, PAGE_SIZE,
3347 			  ohci->misc_buffer, ohci->misc_buffer_bus);
3348 	context_release(&ohci->at_request_ctx);
3349 	context_release(&ohci->at_response_ctx);
3350 	kfree(ohci->it_context_list);
3351 	kfree(ohci->ir_context_list);
3352 	pci_disable_msi(dev);
3353 	pci_iounmap(dev, ohci->registers);
3354 	pci_release_region(dev, 0);
3355 	pci_disable_device(dev);
3356 	kfree(ohci);
3357 	pmac_ohci_off(dev);
3358 
3359 	fw_notify("Removed fw-ohci device.\n");
3360 }
3361 
3362 #ifdef CONFIG_PM
3363 static int pci_suspend(struct pci_dev *dev, pm_message_t state)
3364 {
3365 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3366 	int err;
3367 
3368 	software_reset(ohci);
3369 	free_irq(dev->irq, ohci);
3370 	pci_disable_msi(dev);
3371 	err = pci_save_state(dev);
3372 	if (err) {
3373 		fw_error("pci_save_state failed\n");
3374 		return err;
3375 	}
3376 	err = pci_set_power_state(dev, pci_choose_state(dev, state));
3377 	if (err)
3378 		fw_error("pci_set_power_state failed with %d\n", err);
3379 	pmac_ohci_off(dev);
3380 
3381 	return 0;
3382 }
3383 
3384 static int pci_resume(struct pci_dev *dev)
3385 {
3386 	struct fw_ohci *ohci = pci_get_drvdata(dev);
3387 	int err;
3388 
3389 	pmac_ohci_on(dev);
3390 	pci_set_power_state(dev, PCI_D0);
3391 	pci_restore_state(dev);
3392 	err = pci_enable_device(dev);
3393 	if (err) {
3394 		fw_error("pci_enable_device failed\n");
3395 		return err;
3396 	}
3397 
3398 	/* Some systems don't setup GUID register on resume from ram  */
3399 	if (!reg_read(ohci, OHCI1394_GUIDLo) &&
3400 					!reg_read(ohci, OHCI1394_GUIDHi)) {
3401 		reg_write(ohci, OHCI1394_GUIDLo, (u32)ohci->card.guid);
3402 		reg_write(ohci, OHCI1394_GUIDHi, (u32)(ohci->card.guid >> 32));
3403 	}
3404 
3405 	err = ohci_enable(&ohci->card, NULL, 0);
3406 	if (err)
3407 		return err;
3408 
3409 	ohci_resume_iso_dma(ohci);
3410 
3411 	return 0;
3412 }
3413 #endif
3414 
3415 static const struct pci_device_id pci_table[] = {
3416 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
3417 	{ }
3418 };
3419 
3420 MODULE_DEVICE_TABLE(pci, pci_table);
3421 
3422 static struct pci_driver fw_ohci_pci_driver = {
3423 	.name		= ohci_driver_name,
3424 	.id_table	= pci_table,
3425 	.probe		= pci_probe,
3426 	.remove		= pci_remove,
3427 #ifdef CONFIG_PM
3428 	.resume		= pci_resume,
3429 	.suspend	= pci_suspend,
3430 #endif
3431 };
3432 
3433 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
3434 MODULE_DESCRIPTION("Driver for PCI OHCI IEEE1394 controllers");
3435 MODULE_LICENSE("GPL");
3436 
3437 /* Provide a module alias so root-on-sbp2 initrds don't break. */
3438 #ifndef CONFIG_IEEE1394_OHCI1394_MODULE
3439 MODULE_ALIAS("ohci1394");
3440 #endif
3441 
3442 static int __init fw_ohci_init(void)
3443 {
3444 	return pci_register_driver(&fw_ohci_pci_driver);
3445 }
3446 
3447 static void __exit fw_ohci_cleanup(void)
3448 {
3449 	pci_unregister_driver(&fw_ohci_pci_driver);
3450 }
3451 
3452 module_init(fw_ohci_init);
3453 module_exit(fw_ohci_cleanup);
3454