firewire: add isochronous multichannel reception
[linux-2.6.git] / drivers / firewire / core-iso.c
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
40 int 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, direction);
75                 __free_page(buffer->pages[j]);
76         }
77         kfree(buffer->pages);
78  out:
79         buffer->pages = NULL;
80
81         return -ENOMEM;
82 }
83 EXPORT_SYMBOL(fw_iso_buffer_init);
84
85 int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
86 {
87         unsigned long uaddr;
88         int i, err;
89
90         uaddr = vma->vm_start;
91         for (i = 0; i < buffer->page_count; i++) {
92                 err = vm_insert_page(vma, uaddr, buffer->pages[i]);
93                 if (err)
94                         return err;
95
96                 uaddr += PAGE_SIZE;
97         }
98
99         return 0;
100 }
101
102 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
103                            struct fw_card *card)
104 {
105         int i;
106         dma_addr_t address;
107
108         for (i = 0; i < buffer->page_count; i++) {
109                 address = page_private(buffer->pages[i]);
110                 dma_unmap_page(card->device, address,
111                                PAGE_SIZE, buffer->direction);
112                 __free_page(buffer->pages[i]);
113         }
114
115         kfree(buffer->pages);
116         buffer->pages = NULL;
117 }
118 EXPORT_SYMBOL(fw_iso_buffer_destroy);
119
120 /* Convert DMA address to offset into virtually contiguous buffer. */
121 size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed)
122 {
123         int i;
124         dma_addr_t address;
125         ssize_t offset;
126
127         for (i = 0; i < buffer->page_count; i++) {
128                 address = page_private(buffer->pages[i]);
129                 offset = (ssize_t)completed - (ssize_t)address;
130                 if (offset > 0 && offset <= PAGE_SIZE)
131                         return (i << PAGE_SHIFT) + offset;
132         }
133
134         return 0;
135 }
136
137 struct fw_iso_context *fw_iso_context_create(struct fw_card *card,
138                 int type, int channel, int speed, size_t header_size,
139                 fw_iso_callback_t callback, void *callback_data)
140 {
141         struct fw_iso_context *ctx;
142
143         ctx = card->driver->allocate_iso_context(card,
144                                                  type, channel, header_size);
145         if (IS_ERR(ctx))
146                 return ctx;
147
148         ctx->card = card;
149         ctx->type = type;
150         ctx->channel = channel;
151         ctx->speed = speed;
152         ctx->header_size = header_size;
153         ctx->callback.sc = callback;
154         ctx->callback_data = callback_data;
155
156         return ctx;
157 }
158 EXPORT_SYMBOL(fw_iso_context_create);
159
160 void fw_iso_context_destroy(struct fw_iso_context *ctx)
161 {
162         ctx->card->driver->free_iso_context(ctx);
163 }
164 EXPORT_SYMBOL(fw_iso_context_destroy);
165
166 int fw_iso_context_start(struct fw_iso_context *ctx,
167                          int cycle, int sync, int tags)
168 {
169         return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
170 }
171 EXPORT_SYMBOL(fw_iso_context_start);
172
173 int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels)
174 {
175         return ctx->card->driver->set_iso_channels(ctx, channels);
176 }
177
178 int fw_iso_context_queue(struct fw_iso_context *ctx,
179                          struct fw_iso_packet *packet,
180                          struct fw_iso_buffer *buffer,
181                          unsigned long payload)
182 {
183         return ctx->card->driver->queue_iso(ctx, packet, buffer, payload);
184 }
185 EXPORT_SYMBOL(fw_iso_context_queue);
186
187 int fw_iso_context_stop(struct fw_iso_context *ctx)
188 {
189         return ctx->card->driver->stop_iso(ctx);
190 }
191 EXPORT_SYMBOL(fw_iso_context_stop);
192
193 /*
194  * Isochronous bus resource management (channels, bandwidth), client side
195  */
196
197 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
198                             int bandwidth, bool allocate, __be32 data[2])
199 {
200         int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
201
202         /*
203          * On a 1394a IRM with low contention, try < 1 is enough.
204          * On a 1394-1995 IRM, we need at least try < 2.
205          * Let's just do try < 5.
206          */
207         for (try = 0; try < 5; try++) {
208                 new = allocate ? old - bandwidth : old + bandwidth;
209                 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL)
210                         break;
211
212                 data[0] = cpu_to_be32(old);
213                 data[1] = cpu_to_be32(new);
214                 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
215                                 irm_id, generation, SCODE_100,
216                                 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
217                                 data, 8)) {
218                 case RCODE_GENERATION:
219                         /* A generation change frees all bandwidth. */
220                         return allocate ? -EAGAIN : bandwidth;
221
222                 case RCODE_COMPLETE:
223                         if (be32_to_cpup(data) == old)
224                                 return bandwidth;
225
226                         old = be32_to_cpup(data);
227                         /* Fall through. */
228                 }
229         }
230
231         return -EIO;
232 }
233
234 static int manage_channel(struct fw_card *card, int irm_id, int generation,
235                 u32 channels_mask, u64 offset, bool allocate, __be32 data[2])
236 {
237         __be32 c, all, old;
238         int i, retry = 5;
239
240         old = all = allocate ? cpu_to_be32(~0) : 0;
241
242         for (i = 0; i < 32; i++) {
243                 if (!(channels_mask & 1 << i))
244                         continue;
245
246                 c = cpu_to_be32(1 << (31 - i));
247                 if ((old & c) != (all & c))
248                         continue;
249
250                 data[0] = old;
251                 data[1] = old ^ c;
252                 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
253                                            irm_id, generation, SCODE_100,
254                                            offset, data, 8)) {
255                 case RCODE_GENERATION:
256                         /* A generation change frees all channels. */
257                         return allocate ? -EAGAIN : i;
258
259                 case RCODE_COMPLETE:
260                         if (data[0] == old)
261                                 return i;
262
263                         old = data[0];
264
265                         /* Is the IRM 1394a-2000 compliant? */
266                         if ((data[0] & c) == (data[1] & c))
267                                 continue;
268
269                         /* 1394-1995 IRM, fall through to retry. */
270                 default:
271                         if (retry--)
272                                 i--;
273                 }
274         }
275
276         return -EIO;
277 }
278
279 static void deallocate_channel(struct fw_card *card, int irm_id,
280                                int generation, int channel, __be32 buffer[2])
281 {
282         u32 mask;
283         u64 offset;
284
285         mask = channel < 32 ? 1 << channel : 1 << (channel - 32);
286         offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
287                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
288
289         manage_channel(card, irm_id, generation, mask, offset, false, buffer);
290 }
291
292 /**
293  * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth
294  *
295  * In parameters: card, generation, channels_mask, bandwidth, allocate
296  * Out parameters: channel, bandwidth
297  * This function blocks (sleeps) during communication with the IRM.
298  *
299  * Allocates or deallocates at most one channel out of channels_mask.
300  * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
301  * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
302  * channel 0 and LSB for channel 63.)
303  * Allocates or deallocates as many bandwidth allocation units as specified.
304  *
305  * Returns channel < 0 if no channel was allocated or deallocated.
306  * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
307  *
308  * If generation is stale, deallocations succeed but allocations fail with
309  * channel = -EAGAIN.
310  *
311  * If channel allocation fails, no bandwidth will be allocated either.
312  * If bandwidth allocation fails, no channel will be allocated either.
313  * But deallocations of channel and bandwidth are tried independently
314  * of each other's success.
315  */
316 void fw_iso_resource_manage(struct fw_card *card, int generation,
317                             u64 channels_mask, int *channel, int *bandwidth,
318                             bool allocate, __be32 buffer[2])
319 {
320         u32 channels_hi = channels_mask;        /* channels 31...0 */
321         u32 channels_lo = channels_mask >> 32;  /* channels 63...32 */
322         int irm_id, ret, c = -EINVAL;
323
324         spin_lock_irq(&card->lock);
325         irm_id = card->irm_node->node_id;
326         spin_unlock_irq(&card->lock);
327
328         if (channels_hi)
329                 c = manage_channel(card, irm_id, generation, channels_hi,
330                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
331                                 allocate, buffer);
332         if (channels_lo && c < 0) {
333                 c = manage_channel(card, irm_id, generation, channels_lo,
334                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
335                                 allocate, buffer);
336                 if (c >= 0)
337                         c += 32;
338         }
339         *channel = c;
340
341         if (allocate && channels_mask != 0 && c < 0)
342                 *bandwidth = 0;
343
344         if (*bandwidth == 0)
345                 return;
346
347         ret = manage_bandwidth(card, irm_id, generation, *bandwidth,
348                                allocate, buffer);
349         if (ret < 0)
350                 *bandwidth = 0;
351
352         if (allocate && ret < 0) {
353                 if (c >= 0)
354                         deallocate_channel(card, irm_id, generation, c, buffer);
355                 *channel = ret;
356         }
357 }