include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-3.10.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/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/vmalloc.h>
32
33 #include <asm/byteorder.h>
34
35 #include "core.h"
36
37 /*
38  * Isochronous DMA context management
39  */
40
41 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
42                        int page_count, enum dma_data_direction direction)
43 {
44         int i, j;
45         dma_addr_t address;
46
47         buffer->page_count = page_count;
48         buffer->direction = direction;
49
50         buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
51                                 GFP_KERNEL);
52         if (buffer->pages == NULL)
53                 goto out;
54
55         for (i = 0; i < buffer->page_count; i++) {
56                 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
57                 if (buffer->pages[i] == NULL)
58                         goto out_pages;
59
60                 address = dma_map_page(card->device, buffer->pages[i],
61                                        0, PAGE_SIZE, direction);
62                 if (dma_mapping_error(card->device, address)) {
63                         __free_page(buffer->pages[i]);
64                         goto out_pages;
65                 }
66                 set_page_private(buffer->pages[i], address);
67         }
68
69         return 0;
70
71  out_pages:
72         for (j = 0; j < i; j++) {
73                 address = page_private(buffer->pages[j]);
74                 dma_unmap_page(card->device, address,
75                                PAGE_SIZE, direction);
76                 __free_page(buffer->pages[j]);
77         }
78         kfree(buffer->pages);
79  out:
80         buffer->pages = NULL;
81
82         return -ENOMEM;
83 }
84 EXPORT_SYMBOL(fw_iso_buffer_init);
85
86 int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
87 {
88         unsigned long uaddr;
89         int i, err;
90
91         uaddr = vma->vm_start;
92         for (i = 0; i < buffer->page_count; i++) {
93                 err = vm_insert_page(vma, uaddr, buffer->pages[i]);
94                 if (err)
95                         return err;
96
97                 uaddr += PAGE_SIZE;
98         }
99
100         return 0;
101 }
102
103 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
104                            struct fw_card *card)
105 {
106         int i;
107         dma_addr_t address;
108
109         for (i = 0; i < buffer->page_count; i++) {
110                 address = page_private(buffer->pages[i]);
111                 dma_unmap_page(card->device, address,
112                                PAGE_SIZE, buffer->direction);
113                 __free_page(buffer->pages[i]);
114         }
115
116         kfree(buffer->pages);
117         buffer->pages = NULL;
118 }
119 EXPORT_SYMBOL(fw_iso_buffer_destroy);
120
121 struct fw_iso_context *fw_iso_context_create(struct fw_card *card,
122                 int type, int channel, int speed, size_t header_size,
123                 fw_iso_callback_t callback, void *callback_data)
124 {
125         struct fw_iso_context *ctx;
126
127         ctx = card->driver->allocate_iso_context(card,
128                                                  type, channel, header_size);
129         if (IS_ERR(ctx))
130                 return ctx;
131
132         ctx->card = card;
133         ctx->type = type;
134         ctx->channel = channel;
135         ctx->speed = speed;
136         ctx->header_size = header_size;
137         ctx->callback = callback;
138         ctx->callback_data = callback_data;
139
140         return ctx;
141 }
142 EXPORT_SYMBOL(fw_iso_context_create);
143
144 void fw_iso_context_destroy(struct fw_iso_context *ctx)
145 {
146         struct fw_card *card = ctx->card;
147
148         card->driver->free_iso_context(ctx);
149 }
150 EXPORT_SYMBOL(fw_iso_context_destroy);
151
152 int fw_iso_context_start(struct fw_iso_context *ctx,
153                          int cycle, int sync, int tags)
154 {
155         return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
156 }
157 EXPORT_SYMBOL(fw_iso_context_start);
158
159 int fw_iso_context_queue(struct fw_iso_context *ctx,
160                          struct fw_iso_packet *packet,
161                          struct fw_iso_buffer *buffer,
162                          unsigned long payload)
163 {
164         struct fw_card *card = ctx->card;
165
166         return card->driver->queue_iso(ctx, packet, buffer, payload);
167 }
168 EXPORT_SYMBOL(fw_iso_context_queue);
169
170 int fw_iso_context_stop(struct fw_iso_context *ctx)
171 {
172         return ctx->card->driver->stop_iso(ctx);
173 }
174 EXPORT_SYMBOL(fw_iso_context_stop);
175
176 /*
177  * Isochronous bus resource management (channels, bandwidth), client side
178  */
179
180 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
181                             int bandwidth, bool allocate, __be32 data[2])
182 {
183         int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
184
185         /*
186          * On a 1394a IRM with low contention, try < 1 is enough.
187          * On a 1394-1995 IRM, we need at least try < 2.
188          * Let's just do try < 5.
189          */
190         for (try = 0; try < 5; try++) {
191                 new = allocate ? old - bandwidth : old + bandwidth;
192                 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL)
193                         break;
194
195                 data[0] = cpu_to_be32(old);
196                 data[1] = cpu_to_be32(new);
197                 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
198                                 irm_id, generation, SCODE_100,
199                                 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
200                                 data, 8)) {
201                 case RCODE_GENERATION:
202                         /* A generation change frees all bandwidth. */
203                         return allocate ? -EAGAIN : bandwidth;
204
205                 case RCODE_COMPLETE:
206                         if (be32_to_cpup(data) == old)
207                                 return bandwidth;
208
209                         old = be32_to_cpup(data);
210                         /* Fall through. */
211                 }
212         }
213
214         return -EIO;
215 }
216
217 static int manage_channel(struct fw_card *card, int irm_id, int generation,
218                 u32 channels_mask, u64 offset, bool allocate, __be32 data[2])
219 {
220         __be32 c, all, old;
221         int i, retry = 5;
222
223         old = all = allocate ? cpu_to_be32(~0) : 0;
224
225         for (i = 0; i < 32; i++) {
226                 if (!(channels_mask & 1 << i))
227                         continue;
228
229                 c = cpu_to_be32(1 << (31 - i));
230                 if ((old & c) != (all & c))
231                         continue;
232
233                 data[0] = old;
234                 data[1] = old ^ c;
235                 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
236                                            irm_id, generation, SCODE_100,
237                                            offset, data, 8)) {
238                 case RCODE_GENERATION:
239                         /* A generation change frees all channels. */
240                         return allocate ? -EAGAIN : i;
241
242                 case RCODE_COMPLETE:
243                         if (data[0] == old)
244                                 return i;
245
246                         old = data[0];
247
248                         /* Is the IRM 1394a-2000 compliant? */
249                         if ((data[0] & c) == (data[1] & c))
250                                 continue;
251
252                         /* 1394-1995 IRM, fall through to retry. */
253                 default:
254                         if (retry--)
255                                 i--;
256                 }
257         }
258
259         return -EIO;
260 }
261
262 static void deallocate_channel(struct fw_card *card, int irm_id,
263                                int generation, int channel, __be32 buffer[2])
264 {
265         u32 mask;
266         u64 offset;
267
268         mask = channel < 32 ? 1 << channel : 1 << (channel - 32);
269         offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
270                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
271
272         manage_channel(card, irm_id, generation, mask, offset, false, buffer);
273 }
274
275 /**
276  * fw_iso_resource_manage - Allocate or deallocate a channel and/or bandwidth
277  *
278  * In parameters: card, generation, channels_mask, bandwidth, allocate
279  * Out parameters: channel, bandwidth
280  * This function blocks (sleeps) during communication with the IRM.
281  *
282  * Allocates or deallocates at most one channel out of channels_mask.
283  * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
284  * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
285  * channel 0 and LSB for channel 63.)
286  * Allocates or deallocates as many bandwidth allocation units as specified.
287  *
288  * Returns channel < 0 if no channel was allocated or deallocated.
289  * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
290  *
291  * If generation is stale, deallocations succeed but allocations fail with
292  * channel = -EAGAIN.
293  *
294  * If channel allocation fails, no bandwidth will be allocated either.
295  * If bandwidth allocation fails, no channel will be allocated either.
296  * But deallocations of channel and bandwidth are tried independently
297  * of each other's success.
298  */
299 void fw_iso_resource_manage(struct fw_card *card, int generation,
300                             u64 channels_mask, int *channel, int *bandwidth,
301                             bool allocate, __be32 buffer[2])
302 {
303         u32 channels_hi = channels_mask;        /* channels 31...0 */
304         u32 channels_lo = channels_mask >> 32;  /* channels 63...32 */
305         int irm_id, ret, c = -EINVAL;
306
307         spin_lock_irq(&card->lock);
308         irm_id = card->irm_node->node_id;
309         spin_unlock_irq(&card->lock);
310
311         if (channels_hi)
312                 c = manage_channel(card, irm_id, generation, channels_hi,
313                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
314                                 allocate, buffer);
315         if (channels_lo && c < 0) {
316                 c = manage_channel(card, irm_id, generation, channels_lo,
317                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
318                                 allocate, buffer);
319                 if (c >= 0)
320                         c += 32;
321         }
322         *channel = c;
323
324         if (allocate && channels_mask != 0 && c < 0)
325                 *bandwidth = 0;
326
327         if (*bandwidth == 0)
328                 return;
329
330         ret = manage_bandwidth(card, irm_id, generation, *bandwidth,
331                                allocate, buffer);
332         if (ret < 0)
333                 *bandwidth = 0;
334
335         if (allocate && ret < 0) {
336                 if (c >= 0)
337                         deallocate_channel(card, irm_id, generation, c, buffer);
338                 *channel = ret;
339         }
340 }