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-rw-r--r--drivers/firewire/core-iso.c329
1 files changed, 329 insertions, 0 deletions
diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c
new file mode 100644
index 00000000000..28076c892d7
--- /dev/null
+++ b/drivers/firewire/core-iso.c
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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/spinlock.h>
30#include <linux/vmalloc.h>
31
32#include <asm/byteorder.h>
33
34#include "core.h"
35
36/*
37 * Isochronous DMA context management
38 */
39
40int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
41 int page_count, enum dma_data_direction direction)
42{
43 int i, j;
44 dma_addr_t address;
45
46 buffer->page_count = page_count;
47 buffer->direction = direction;
48
49 buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
50 GFP_KERNEL);
51 if (buffer->pages == NULL)
52 goto out;
53
54 for (i = 0; i < buffer->page_count; i++) {
55 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
56 if (buffer->pages[i] == NULL)
57 goto out_pages;
58
59 address = dma_map_page(card->device, buffer->pages[i],
60 0, PAGE_SIZE, direction);
61 if (dma_mapping_error(card->device, address)) {
62 __free_page(buffer->pages[i]);
63 goto out_pages;
64 }
65 set_page_private(buffer->pages[i], address);
66 }
67
68 return 0;
69
70 out_pages:
71 for (j = 0; j < i; j++) {
72 address = page_private(buffer->pages[j]);
73 dma_unmap_page(card->device, address,
74 PAGE_SIZE, DMA_TO_DEVICE);
75 __free_page(buffer->pages[j]);
76 }
77 kfree(buffer->pages);
78 out:
79 buffer->pages = NULL;
80
81 return -ENOMEM;
82}
83
84int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
85{
86 unsigned long uaddr;
87 int i, err;
88
89 uaddr = vma->vm_start;
90 for (i = 0; i < buffer->page_count; i++) {
91 err = vm_insert_page(vma, uaddr, buffer->pages[i]);
92 if (err)
93 return err;
94
95 uaddr += PAGE_SIZE;
96 }
97
98 return 0;
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; i++) {
108 address = page_private(buffer->pages[i]);
109 dma_unmap_page(card->device, address,
110 PAGE_SIZE, DMA_TO_DEVICE);
111 __free_page(buffer->pages[i]);
112 }
113
114 kfree(buffer->pages);
115 buffer->pages = NULL;
116}
117
118struct fw_iso_context *fw_iso_context_create(struct fw_card *card,
119 int type, int channel, int speed, size_t header_size,
120 fw_iso_callback_t callback, void *callback_data)
121{
122 struct fw_iso_context *ctx;
123
124 ctx = card->driver->allocate_iso_context(card,
125 type, channel, header_size);
126 if (IS_ERR(ctx))
127 return ctx;
128
129 ctx->card = card;
130 ctx->type = type;
131 ctx->channel = channel;
132 ctx->speed = speed;
133 ctx->header_size = header_size;
134 ctx->callback = callback;
135 ctx->callback_data = callback_data;
136
137 return ctx;
138}
139
140void fw_iso_context_destroy(struct fw_iso_context *ctx)
141{
142 struct fw_card *card = ctx->card;
143
144 card->driver->free_iso_context(ctx);
145}
146
147int fw_iso_context_start(struct fw_iso_context *ctx,
148 int cycle, int sync, int tags)
149{
150 return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
151}
152
153int fw_iso_context_queue(struct fw_iso_context *ctx,
154 struct fw_iso_packet *packet,
155 struct fw_iso_buffer *buffer,
156 unsigned long payload)
157{
158 struct fw_card *card = ctx->card;
159
160 return card->driver->queue_iso(ctx, packet, buffer, payload);
161}
162
163int fw_iso_context_stop(struct fw_iso_context *ctx)
164{
165 return ctx->card->driver->stop_iso(ctx);
166}
167
168/*
169 * Isochronous bus resource management (channels, bandwidth), client side
170 */
171
172static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
173 int bandwidth, bool allocate)
174{
175 __be32 data[2];
176 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
177
178 /*
179 * On a 1394a IRM with low contention, try < 1 is enough.
180 * On a 1394-1995 IRM, we need at least try < 2.
181 * Let's just do try < 5.
182 */
183 for (try = 0; try < 5; try++) {
184 new = allocate ? old - bandwidth : old + bandwidth;
185 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL)
186 break;
187
188 data[0] = cpu_to_be32(old);
189 data[1] = cpu_to_be32(new);
190 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
191 irm_id, generation, SCODE_100,
192 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
193 data, sizeof(data))) {
194 case RCODE_GENERATION:
195 /* A generation change frees all bandwidth. */
196 return allocate ? -EAGAIN : bandwidth;
197
198 case RCODE_COMPLETE:
199 if (be32_to_cpup(data) == old)
200 return bandwidth;
201
202 old = be32_to_cpup(data);
203 /* Fall through. */
204 }
205 }
206
207 return -EIO;
208}
209
210static int manage_channel(struct fw_card *card, int irm_id, int generation,
211 u32 channels_mask, u64 offset, bool allocate)
212{
213 __be32 data[2], c, all, old;
214 int i, retry = 5;
215
216 old = all = allocate ? cpu_to_be32(~0) : 0;
217
218 for (i = 0; i < 32; i++) {
219 if (!(channels_mask & 1 << i))
220 continue;
221
222 c = cpu_to_be32(1 << (31 - i));
223 if ((old & c) != (all & c))
224 continue;
225
226 data[0] = old;
227 data[1] = old ^ c;
228 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
229 irm_id, generation, SCODE_100,
230 offset, data, sizeof(data))) {
231 case RCODE_GENERATION:
232 /* A generation change frees all channels. */
233 return allocate ? -EAGAIN : i;
234
235 case RCODE_COMPLETE:
236 if (data[0] == old)
237 return i;
238
239 old = data[0];
240
241 /* Is the IRM 1394a-2000 compliant? */
242 if ((data[0] & c) == (data[1] & c))
243 continue;
244
245 /* 1394-1995 IRM, fall through to retry. */
246 default:
247 if (retry--)
248 i--;
249 }
250 }
251
252 return -EIO;
253}
254
255static void deallocate_channel(struct fw_card *card, int irm_id,
256 int generation, int channel)
257{
258 u32 mask;
259 u64 offset;
260
261 mask = channel < 32 ? 1 << channel : 1 << (channel - 32);
262 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
263 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
264
265 manage_channel(card, irm_id, generation, mask, offset, false);
266}
267
268/**
269 * fw_iso_resource_manage - Allocate or deallocate a channel and/or bandwidth
270 *
271 * In parameters: card, generation, channels_mask, bandwidth, allocate
272 * Out parameters: channel, bandwidth
273 * This function blocks (sleeps) during communication with the IRM.
274 *
275 * Allocates or deallocates at most one channel out of channels_mask.
276 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
277 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
278 * channel 0 and LSB for channel 63.)
279 * Allocates or deallocates as many bandwidth allocation units as specified.
280 *
281 * Returns channel < 0 if no channel was allocated or deallocated.
282 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
283 *
284 * If generation is stale, deallocations succeed but allocations fail with
285 * channel = -EAGAIN.
286 *
287 * If channel allocation fails, no bandwidth will be allocated either.
288 * If bandwidth allocation fails, no channel will be allocated either.
289 * But deallocations of channel and bandwidth are tried independently
290 * of each other's success.
291 */
292void fw_iso_resource_manage(struct fw_card *card, int generation,
293 u64 channels_mask, int *channel, int *bandwidth,
294 bool allocate)
295{
296 u32 channels_hi = channels_mask; /* channels 31...0 */
297 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */
298 int irm_id, ret, c = -EINVAL;
299
300 spin_lock_irq(&card->lock);
301 irm_id = card->irm_node->node_id;
302 spin_unlock_irq(&card->lock);
303
304 if (channels_hi)
305 c = manage_channel(card, irm_id, generation, channels_hi,
306 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, allocate);
307 if (channels_lo && c < 0) {
308 c = manage_channel(card, irm_id, generation, channels_lo,
309 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, allocate);
310 if (c >= 0)
311 c += 32;
312 }
313 *channel = c;
314
315 if (allocate && channels_mask != 0 && c < 0)
316 *bandwidth = 0;
317
318 if (*bandwidth == 0)
319 return;
320
321 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
322 if (ret < 0)
323 *bandwidth = 0;
324
325 if (allocate && ret < 0 && c >= 0) {
326 deallocate_channel(card, irm_id, generation, c);
327 *channel = ret;
328 }
329}