Loading...
1/*
2 * Isochronous I/O functionality:
3 * - Isochronous DMA context management
4 * - Isochronous bus resource management (channels, bandwidth), client side
5 *
6 * Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software Foundation,
20 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 */
22
23#include <linux/dma-mapping.h>
24#include <linux/errno.h>
25#include <linux/firewire.h>
26#include <linux/firewire-constants.h>
27#include <linux/kernel.h>
28#include <linux/mm.h>
29#include <linux/slab.h>
30#include <linux/spinlock.h>
31#include <linux/vmalloc.h>
32#include <linux/export.h>
33
34#include <asm/byteorder.h>
35
36#include "core.h"
37
38/*
39 * Isochronous DMA context management
40 */
41
42int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count)
43{
44 int i;
45
46 buffer->page_count = 0;
47 buffer->page_count_mapped = 0;
48 buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
49 GFP_KERNEL);
50 if (buffer->pages == NULL)
51 return -ENOMEM;
52
53 for (i = 0; i < page_count; i++) {
54 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
55 if (buffer->pages[i] == NULL)
56 break;
57 }
58 buffer->page_count = i;
59 if (i < page_count) {
60 fw_iso_buffer_destroy(buffer, NULL);
61 return -ENOMEM;
62 }
63
64 return 0;
65}
66
67int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card,
68 enum dma_data_direction direction)
69{
70 dma_addr_t address;
71 int i;
72
73 buffer->direction = direction;
74
75 for (i = 0; i < buffer->page_count; i++) {
76 address = dma_map_page(card->device, buffer->pages[i],
77 0, PAGE_SIZE, direction);
78 if (dma_mapping_error(card->device, address))
79 break;
80
81 set_page_private(buffer->pages[i], address);
82 }
83 buffer->page_count_mapped = i;
84 if (i < buffer->page_count)
85 return -ENOMEM;
86
87 return 0;
88}
89
90int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
91 int page_count, enum dma_data_direction direction)
92{
93 int ret;
94
95 ret = fw_iso_buffer_alloc(buffer, page_count);
96 if (ret < 0)
97 return ret;
98
99 ret = fw_iso_buffer_map_dma(buffer, card, direction);
100 if (ret < 0)
101 fw_iso_buffer_destroy(buffer, card);
102
103 return ret;
104}
105EXPORT_SYMBOL(fw_iso_buffer_init);
106
107int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer,
108 struct vm_area_struct *vma)
109{
110 unsigned long uaddr;
111 int i, err;
112
113 uaddr = vma->vm_start;
114 for (i = 0; i < buffer->page_count; i++) {
115 err = vm_insert_page(vma, uaddr, buffer->pages[i]);
116 if (err)
117 return err;
118
119 uaddr += PAGE_SIZE;
120 }
121
122 return 0;
123}
124
125void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
126 struct fw_card *card)
127{
128 int i;
129 dma_addr_t address;
130
131 for (i = 0; i < buffer->page_count_mapped; i++) {
132 address = page_private(buffer->pages[i]);
133 dma_unmap_page(card->device, address,
134 PAGE_SIZE, buffer->direction);
135 }
136 for (i = 0; i < buffer->page_count; i++)
137 __free_page(buffer->pages[i]);
138
139 kfree(buffer->pages);
140 buffer->pages = NULL;
141 buffer->page_count = 0;
142 buffer->page_count_mapped = 0;
143}
144EXPORT_SYMBOL(fw_iso_buffer_destroy);
145
146/* Convert DMA address to offset into virtually contiguous buffer. */
147size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed)
148{
149 int i;
150 dma_addr_t address;
151 ssize_t offset;
152
153 for (i = 0; i < buffer->page_count; i++) {
154 address = page_private(buffer->pages[i]);
155 offset = (ssize_t)completed - (ssize_t)address;
156 if (offset > 0 && offset <= PAGE_SIZE)
157 return (i << PAGE_SHIFT) + offset;
158 }
159
160 return 0;
161}
162
163struct fw_iso_context *fw_iso_context_create(struct fw_card *card,
164 int type, int channel, int speed, size_t header_size,
165 fw_iso_callback_t callback, void *callback_data)
166{
167 struct fw_iso_context *ctx;
168
169 ctx = card->driver->allocate_iso_context(card,
170 type, channel, header_size);
171 if (IS_ERR(ctx))
172 return ctx;
173
174 ctx->card = card;
175 ctx->type = type;
176 ctx->channel = channel;
177 ctx->speed = speed;
178 ctx->header_size = header_size;
179 ctx->callback.sc = callback;
180 ctx->callback_data = callback_data;
181
182 return ctx;
183}
184EXPORT_SYMBOL(fw_iso_context_create);
185
186void fw_iso_context_destroy(struct fw_iso_context *ctx)
187{
188 ctx->card->driver->free_iso_context(ctx);
189}
190EXPORT_SYMBOL(fw_iso_context_destroy);
191
192int fw_iso_context_start(struct fw_iso_context *ctx,
193 int cycle, int sync, int tags)
194{
195 return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
196}
197EXPORT_SYMBOL(fw_iso_context_start);
198
199int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels)
200{
201 return ctx->card->driver->set_iso_channels(ctx, channels);
202}
203
204int fw_iso_context_queue(struct fw_iso_context *ctx,
205 struct fw_iso_packet *packet,
206 struct fw_iso_buffer *buffer,
207 unsigned long payload)
208{
209 return ctx->card->driver->queue_iso(ctx, packet, buffer, payload);
210}
211EXPORT_SYMBOL(fw_iso_context_queue);
212
213void fw_iso_context_queue_flush(struct fw_iso_context *ctx)
214{
215 ctx->card->driver->flush_queue_iso(ctx);
216}
217EXPORT_SYMBOL(fw_iso_context_queue_flush);
218
219int fw_iso_context_flush_completions(struct fw_iso_context *ctx)
220{
221 return ctx->card->driver->flush_iso_completions(ctx);
222}
223EXPORT_SYMBOL(fw_iso_context_flush_completions);
224
225int fw_iso_context_stop(struct fw_iso_context *ctx)
226{
227 return ctx->card->driver->stop_iso(ctx);
228}
229EXPORT_SYMBOL(fw_iso_context_stop);
230
231/*
232 * Isochronous bus resource management (channels, bandwidth), client side
233 */
234
235static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
236 int bandwidth, bool allocate)
237{
238 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
239 __be32 data[2];
240
241 /*
242 * On a 1394a IRM with low contention, try < 1 is enough.
243 * On a 1394-1995 IRM, we need at least try < 2.
244 * Let's just do try < 5.
245 */
246 for (try = 0; try < 5; try++) {
247 new = allocate ? old - bandwidth : old + bandwidth;
248 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL)
249 return -EBUSY;
250
251 data[0] = cpu_to_be32(old);
252 data[1] = cpu_to_be32(new);
253 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
254 irm_id, generation, SCODE_100,
255 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
256 data, 8)) {
257 case RCODE_GENERATION:
258 /* A generation change frees all bandwidth. */
259 return allocate ? -EAGAIN : bandwidth;
260
261 case RCODE_COMPLETE:
262 if (be32_to_cpup(data) == old)
263 return bandwidth;
264
265 old = be32_to_cpup(data);
266 /* Fall through. */
267 }
268 }
269
270 return -EIO;
271}
272
273static int manage_channel(struct fw_card *card, int irm_id, int generation,
274 u32 channels_mask, u64 offset, bool allocate)
275{
276 __be32 bit, all, old;
277 __be32 data[2];
278 int channel, ret = -EIO, retry = 5;
279
280 old = all = allocate ? cpu_to_be32(~0) : 0;
281
282 for (channel = 0; channel < 32; channel++) {
283 if (!(channels_mask & 1 << channel))
284 continue;
285
286 ret = -EBUSY;
287
288 bit = cpu_to_be32(1 << (31 - channel));
289 if ((old & bit) != (all & bit))
290 continue;
291
292 data[0] = old;
293 data[1] = old ^ bit;
294 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
295 irm_id, generation, SCODE_100,
296 offset, data, 8)) {
297 case RCODE_GENERATION:
298 /* A generation change frees all channels. */
299 return allocate ? -EAGAIN : channel;
300
301 case RCODE_COMPLETE:
302 if (data[0] == old)
303 return channel;
304
305 old = data[0];
306
307 /* Is the IRM 1394a-2000 compliant? */
308 if ((data[0] & bit) == (data[1] & bit))
309 continue;
310
311 /* 1394-1995 IRM, fall through to retry. */
312 default:
313 if (retry) {
314 retry--;
315 channel--;
316 } else {
317 ret = -EIO;
318 }
319 }
320 }
321
322 return ret;
323}
324
325static void deallocate_channel(struct fw_card *card, int irm_id,
326 int generation, int channel)
327{
328 u32 mask;
329 u64 offset;
330
331 mask = channel < 32 ? 1 << channel : 1 << (channel - 32);
332 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
333 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
334
335 manage_channel(card, irm_id, generation, mask, offset, false);
336}
337
338/**
339 * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth
340 *
341 * In parameters: card, generation, channels_mask, bandwidth, allocate
342 * Out parameters: channel, bandwidth
343 * This function blocks (sleeps) during communication with the IRM.
344 *
345 * Allocates or deallocates at most one channel out of channels_mask.
346 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
347 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
348 * channel 0 and LSB for channel 63.)
349 * Allocates or deallocates as many bandwidth allocation units as specified.
350 *
351 * Returns channel < 0 if no channel was allocated or deallocated.
352 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
353 *
354 * If generation is stale, deallocations succeed but allocations fail with
355 * channel = -EAGAIN.
356 *
357 * If channel allocation fails, no bandwidth will be allocated either.
358 * If bandwidth allocation fails, no channel will be allocated either.
359 * But deallocations of channel and bandwidth are tried independently
360 * of each other's success.
361 */
362void fw_iso_resource_manage(struct fw_card *card, int generation,
363 u64 channels_mask, int *channel, int *bandwidth,
364 bool allocate)
365{
366 u32 channels_hi = channels_mask; /* channels 31...0 */
367 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */
368 int irm_id, ret, c = -EINVAL;
369
370 spin_lock_irq(&card->lock);
371 irm_id = card->irm_node->node_id;
372 spin_unlock_irq(&card->lock);
373
374 if (channels_hi)
375 c = manage_channel(card, irm_id, generation, channels_hi,
376 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
377 allocate);
378 if (channels_lo && c < 0) {
379 c = manage_channel(card, irm_id, generation, channels_lo,
380 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
381 allocate);
382 if (c >= 0)
383 c += 32;
384 }
385 *channel = c;
386
387 if (allocate && channels_mask != 0 && c < 0)
388 *bandwidth = 0;
389
390 if (*bandwidth == 0)
391 return;
392
393 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
394 if (ret < 0)
395 *bandwidth = 0;
396
397 if (allocate && ret < 0) {
398 if (c >= 0)
399 deallocate_channel(card, irm_id, generation, c);
400 *channel = ret;
401 }
402}
403EXPORT_SYMBOL(fw_iso_resource_manage);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Isochronous I/O functionality:
4 * - Isochronous DMA context management
5 * - Isochronous bus resource management (channels, bandwidth), client side
6 *
7 * Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net>
8 */
9
10#include <linux/dma-mapping.h>
11#include <linux/errno.h>
12#include <linux/firewire.h>
13#include <linux/firewire-constants.h>
14#include <linux/kernel.h>
15#include <linux/mm.h>
16#include <linux/slab.h>
17#include <linux/spinlock.h>
18#include <linux/vmalloc.h>
19#include <linux/export.h>
20
21#include <asm/byteorder.h>
22
23#include "core.h"
24
25/*
26 * Isochronous DMA context management
27 */
28
29int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count)
30{
31 int i;
32
33 buffer->page_count = 0;
34 buffer->page_count_mapped = 0;
35 buffer->pages = kmalloc_array(page_count, sizeof(buffer->pages[0]),
36 GFP_KERNEL);
37 if (buffer->pages == NULL)
38 return -ENOMEM;
39
40 for (i = 0; i < page_count; i++) {
41 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
42 if (buffer->pages[i] == NULL)
43 break;
44 }
45 buffer->page_count = i;
46 if (i < page_count) {
47 fw_iso_buffer_destroy(buffer, NULL);
48 return -ENOMEM;
49 }
50
51 return 0;
52}
53
54int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card,
55 enum dma_data_direction direction)
56{
57 dma_addr_t address;
58 int i;
59
60 buffer->direction = direction;
61
62 for (i = 0; i < buffer->page_count; i++) {
63 address = dma_map_page(card->device, buffer->pages[i],
64 0, PAGE_SIZE, direction);
65 if (dma_mapping_error(card->device, address))
66 break;
67
68 set_page_private(buffer->pages[i], address);
69 }
70 buffer->page_count_mapped = i;
71 if (i < buffer->page_count)
72 return -ENOMEM;
73
74 return 0;
75}
76
77int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
78 int page_count, enum dma_data_direction direction)
79{
80 int ret;
81
82 ret = fw_iso_buffer_alloc(buffer, page_count);
83 if (ret < 0)
84 return ret;
85
86 ret = fw_iso_buffer_map_dma(buffer, card, direction);
87 if (ret < 0)
88 fw_iso_buffer_destroy(buffer, card);
89
90 return ret;
91}
92EXPORT_SYMBOL(fw_iso_buffer_init);
93
94int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer,
95 struct vm_area_struct *vma)
96{
97 return vm_map_pages_zero(vma, buffer->pages,
98 buffer->page_count);
99}
100
101void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
102 struct fw_card *card)
103{
104 int i;
105 dma_addr_t address;
106
107 for (i = 0; i < buffer->page_count_mapped; i++) {
108 address = page_private(buffer->pages[i]);
109 dma_unmap_page(card->device, address,
110 PAGE_SIZE, buffer->direction);
111 }
112 for (i = 0; i < buffer->page_count; i++)
113 __free_page(buffer->pages[i]);
114
115 kfree(buffer->pages);
116 buffer->pages = NULL;
117 buffer->page_count = 0;
118 buffer->page_count_mapped = 0;
119}
120EXPORT_SYMBOL(fw_iso_buffer_destroy);
121
122/* Convert DMA address to offset into virtually contiguous buffer. */
123size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed)
124{
125 size_t i;
126 dma_addr_t address;
127 ssize_t offset;
128
129 for (i = 0; i < buffer->page_count; i++) {
130 address = page_private(buffer->pages[i]);
131 offset = (ssize_t)completed - (ssize_t)address;
132 if (offset > 0 && offset <= PAGE_SIZE)
133 return (i << PAGE_SHIFT) + offset;
134 }
135
136 return 0;
137}
138
139struct fw_iso_context *fw_iso_context_create(struct fw_card *card,
140 int type, int channel, int speed, size_t header_size,
141 fw_iso_callback_t callback, void *callback_data)
142{
143 struct fw_iso_context *ctx;
144
145 ctx = card->driver->allocate_iso_context(card,
146 type, channel, header_size);
147 if (IS_ERR(ctx))
148 return ctx;
149
150 ctx->card = card;
151 ctx->type = type;
152 ctx->channel = channel;
153 ctx->speed = speed;
154 ctx->header_size = header_size;
155 ctx->callback.sc = callback;
156 ctx->callback_data = callback_data;
157
158 return ctx;
159}
160EXPORT_SYMBOL(fw_iso_context_create);
161
162void fw_iso_context_destroy(struct fw_iso_context *ctx)
163{
164 ctx->card->driver->free_iso_context(ctx);
165}
166EXPORT_SYMBOL(fw_iso_context_destroy);
167
168int fw_iso_context_start(struct fw_iso_context *ctx,
169 int cycle, int sync, int tags)
170{
171 return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
172}
173EXPORT_SYMBOL(fw_iso_context_start);
174
175int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels)
176{
177 return ctx->card->driver->set_iso_channels(ctx, channels);
178}
179
180int fw_iso_context_queue(struct fw_iso_context *ctx,
181 struct fw_iso_packet *packet,
182 struct fw_iso_buffer *buffer,
183 unsigned long payload)
184{
185 return ctx->card->driver->queue_iso(ctx, packet, buffer, payload);
186}
187EXPORT_SYMBOL(fw_iso_context_queue);
188
189void fw_iso_context_queue_flush(struct fw_iso_context *ctx)
190{
191 ctx->card->driver->flush_queue_iso(ctx);
192}
193EXPORT_SYMBOL(fw_iso_context_queue_flush);
194
195int fw_iso_context_flush_completions(struct fw_iso_context *ctx)
196{
197 return ctx->card->driver->flush_iso_completions(ctx);
198}
199EXPORT_SYMBOL(fw_iso_context_flush_completions);
200
201int fw_iso_context_stop(struct fw_iso_context *ctx)
202{
203 return ctx->card->driver->stop_iso(ctx);
204}
205EXPORT_SYMBOL(fw_iso_context_stop);
206
207/*
208 * Isochronous bus resource management (channels, bandwidth), client side
209 */
210
211static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
212 int bandwidth, bool allocate)
213{
214 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
215 __be32 data[2];
216
217 /*
218 * On a 1394a IRM with low contention, try < 1 is enough.
219 * On a 1394-1995 IRM, we need at least try < 2.
220 * Let's just do try < 5.
221 */
222 for (try = 0; try < 5; try++) {
223 new = allocate ? old - bandwidth : old + bandwidth;
224 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL)
225 return -EBUSY;
226
227 data[0] = cpu_to_be32(old);
228 data[1] = cpu_to_be32(new);
229 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
230 irm_id, generation, SCODE_100,
231 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
232 data, 8)) {
233 case RCODE_GENERATION:
234 /* A generation change frees all bandwidth. */
235 return allocate ? -EAGAIN : bandwidth;
236
237 case RCODE_COMPLETE:
238 if (be32_to_cpup(data) == old)
239 return bandwidth;
240
241 old = be32_to_cpup(data);
242 /* Fall through. */
243 }
244 }
245
246 return -EIO;
247}
248
249static int manage_channel(struct fw_card *card, int irm_id, int generation,
250 u32 channels_mask, u64 offset, bool allocate)
251{
252 __be32 bit, all, old;
253 __be32 data[2];
254 int channel, ret = -EIO, retry = 5;
255
256 old = all = allocate ? cpu_to_be32(~0) : 0;
257
258 for (channel = 0; channel < 32; channel++) {
259 if (!(channels_mask & 1 << channel))
260 continue;
261
262 ret = -EBUSY;
263
264 bit = cpu_to_be32(1 << (31 - channel));
265 if ((old & bit) != (all & bit))
266 continue;
267
268 data[0] = old;
269 data[1] = old ^ bit;
270 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
271 irm_id, generation, SCODE_100,
272 offset, data, 8)) {
273 case RCODE_GENERATION:
274 /* A generation change frees all channels. */
275 return allocate ? -EAGAIN : channel;
276
277 case RCODE_COMPLETE:
278 if (data[0] == old)
279 return channel;
280
281 old = data[0];
282
283 /* Is the IRM 1394a-2000 compliant? */
284 if ((data[0] & bit) == (data[1] & bit))
285 continue;
286
287 /* fall through - It's a 1394-1995 IRM, retry. */
288 default:
289 if (retry) {
290 retry--;
291 channel--;
292 } else {
293 ret = -EIO;
294 }
295 }
296 }
297
298 return ret;
299}
300
301static void deallocate_channel(struct fw_card *card, int irm_id,
302 int generation, int channel)
303{
304 u32 mask;
305 u64 offset;
306
307 mask = channel < 32 ? 1 << channel : 1 << (channel - 32);
308 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
309 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
310
311 manage_channel(card, irm_id, generation, mask, offset, false);
312}
313
314/**
315 * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth
316 * @card: card interface for this action
317 * @generation: bus generation
318 * @channels_mask: bitmask for channel allocation
319 * @channel: pointer for returning channel allocation result
320 * @bandwidth: pointer for returning bandwidth allocation result
321 * @allocate: whether to allocate (true) or deallocate (false)
322 *
323 * In parameters: card, generation, channels_mask, bandwidth, allocate
324 * Out parameters: channel, bandwidth
325 *
326 * This function blocks (sleeps) during communication with the IRM.
327 *
328 * Allocates or deallocates at most one channel out of channels_mask.
329 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
330 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
331 * channel 0 and LSB for channel 63.)
332 * Allocates or deallocates as many bandwidth allocation units as specified.
333 *
334 * Returns channel < 0 if no channel was allocated or deallocated.
335 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
336 *
337 * If generation is stale, deallocations succeed but allocations fail with
338 * channel = -EAGAIN.
339 *
340 * If channel allocation fails, no bandwidth will be allocated either.
341 * If bandwidth allocation fails, no channel will be allocated either.
342 * But deallocations of channel and bandwidth are tried independently
343 * of each other's success.
344 */
345void fw_iso_resource_manage(struct fw_card *card, int generation,
346 u64 channels_mask, int *channel, int *bandwidth,
347 bool allocate)
348{
349 u32 channels_hi = channels_mask; /* channels 31...0 */
350 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */
351 int irm_id, ret, c = -EINVAL;
352
353 spin_lock_irq(&card->lock);
354 irm_id = card->irm_node->node_id;
355 spin_unlock_irq(&card->lock);
356
357 if (channels_hi)
358 c = manage_channel(card, irm_id, generation, channels_hi,
359 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
360 allocate);
361 if (channels_lo && c < 0) {
362 c = manage_channel(card, irm_id, generation, channels_lo,
363 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
364 allocate);
365 if (c >= 0)
366 c += 32;
367 }
368 *channel = c;
369
370 if (allocate && channels_mask != 0 && c < 0)
371 *bandwidth = 0;
372
373 if (*bandwidth == 0)
374 return;
375
376 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
377 if (ret < 0)
378 *bandwidth = 0;
379
380 if (allocate && ret < 0) {
381 if (c >= 0)
382 deallocate_channel(card, irm_id, generation, c);
383 *channel = ret;
384 }
385}
386EXPORT_SYMBOL(fw_iso_resource_manage);