Merge tag 'firewire-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee139...
[~shefty/rdma-dev.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 #include <linux/export.h>
33
34 #include <asm/byteorder.h>
35
36 #include "core.h"
37
38 /*
39  * Isochronous DMA context management
40  */
41
42 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
43                        int page_count, enum dma_data_direction direction)
44 {
45         int i, j;
46         dma_addr_t address;
47
48         buffer->page_count = page_count;
49         buffer->direction = direction;
50
51         buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
52                                 GFP_KERNEL);
53         if (buffer->pages == NULL)
54                 goto out;
55
56         for (i = 0; i < buffer->page_count; i++) {
57                 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO);
58                 if (buffer->pages[i] == NULL)
59                         goto out_pages;
60
61                 address = dma_map_page(card->device, buffer->pages[i],
62                                        0, PAGE_SIZE, direction);
63                 if (dma_mapping_error(card->device, address)) {
64                         __free_page(buffer->pages[i]);
65                         goto out_pages;
66                 }
67                 set_page_private(buffer->pages[i], address);
68         }
69
70         return 0;
71
72  out_pages:
73         for (j = 0; j < i; j++) {
74                 address = page_private(buffer->pages[j]);
75                 dma_unmap_page(card->device, address,
76                                PAGE_SIZE, direction);
77                 __free_page(buffer->pages[j]);
78         }
79         kfree(buffer->pages);
80  out:
81         buffer->pages = NULL;
82
83         return -ENOMEM;
84 }
85 EXPORT_SYMBOL(fw_iso_buffer_init);
86
87 int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
88 {
89         unsigned long uaddr;
90         int i, err;
91
92         uaddr = vma->vm_start;
93         for (i = 0; i < buffer->page_count; i++) {
94                 err = vm_insert_page(vma, uaddr, buffer->pages[i]);
95                 if (err)
96                         return err;
97
98                 uaddr += PAGE_SIZE;
99         }
100
101         return 0;
102 }
103
104 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
105                            struct fw_card *card)
106 {
107         int i;
108         dma_addr_t address;
109
110         for (i = 0; i < buffer->page_count; i++) {
111                 address = page_private(buffer->pages[i]);
112                 dma_unmap_page(card->device, address,
113                                PAGE_SIZE, buffer->direction);
114                 __free_page(buffer->pages[i]);
115         }
116
117         kfree(buffer->pages);
118         buffer->pages = NULL;
119 }
120 EXPORT_SYMBOL(fw_iso_buffer_destroy);
121
122 /* Convert DMA address to offset into virtually contiguous buffer. */
123 size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed)
124 {
125         int 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
139 struct 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 }
160 EXPORT_SYMBOL(fw_iso_context_create);
161
162 void fw_iso_context_destroy(struct fw_iso_context *ctx)
163 {
164         ctx->card->driver->free_iso_context(ctx);
165 }
166 EXPORT_SYMBOL(fw_iso_context_destroy);
167
168 int 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 }
173 EXPORT_SYMBOL(fw_iso_context_start);
174
175 int 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
180 int 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 }
187 EXPORT_SYMBOL(fw_iso_context_queue);
188
189 void fw_iso_context_queue_flush(struct fw_iso_context *ctx)
190 {
191         ctx->card->driver->flush_queue_iso(ctx);
192 }
193 EXPORT_SYMBOL(fw_iso_context_queue_flush);
194
195 int fw_iso_context_flush_completions(struct fw_iso_context *ctx)
196 {
197         return ctx->card->driver->flush_iso_completions(ctx);
198 }
199 EXPORT_SYMBOL(fw_iso_context_flush_completions);
200
201 int fw_iso_context_stop(struct fw_iso_context *ctx)
202 {
203         return ctx->card->driver->stop_iso(ctx);
204 }
205 EXPORT_SYMBOL(fw_iso_context_stop);
206
207 /*
208  * Isochronous bus resource management (channels, bandwidth), client side
209  */
210
211 static 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
249 static 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                         /* 1394-1995 IRM, fall through to retry. */
288                 default:
289                         if (retry) {
290                                 retry--;
291                                 channel--;
292                         } else {
293                                 ret = -EIO;
294                         }
295                 }
296         }
297
298         return ret;
299 }
300
301 static 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  *
317  * In parameters: card, generation, channels_mask, bandwidth, allocate
318  * Out parameters: channel, bandwidth
319  * This function blocks (sleeps) during communication with the IRM.
320  *
321  * Allocates or deallocates at most one channel out of channels_mask.
322  * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
323  * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
324  * channel 0 and LSB for channel 63.)
325  * Allocates or deallocates as many bandwidth allocation units as specified.
326  *
327  * Returns channel < 0 if no channel was allocated or deallocated.
328  * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
329  *
330  * If generation is stale, deallocations succeed but allocations fail with
331  * channel = -EAGAIN.
332  *
333  * If channel allocation fails, no bandwidth will be allocated either.
334  * If bandwidth allocation fails, no channel will be allocated either.
335  * But deallocations of channel and bandwidth are tried independently
336  * of each other's success.
337  */
338 void fw_iso_resource_manage(struct fw_card *card, int generation,
339                             u64 channels_mask, int *channel, int *bandwidth,
340                             bool allocate)
341 {
342         u32 channels_hi = channels_mask;        /* channels 31...0 */
343         u32 channels_lo = channels_mask >> 32;  /* channels 63...32 */
344         int irm_id, ret, c = -EINVAL;
345
346         spin_lock_irq(&card->lock);
347         irm_id = card->irm_node->node_id;
348         spin_unlock_irq(&card->lock);
349
350         if (channels_hi)
351                 c = manage_channel(card, irm_id, generation, channels_hi,
352                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
353                                 allocate);
354         if (channels_lo && c < 0) {
355                 c = manage_channel(card, irm_id, generation, channels_lo,
356                                 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
357                                 allocate);
358                 if (c >= 0)
359                         c += 32;
360         }
361         *channel = c;
362
363         if (allocate && channels_mask != 0 && c < 0)
364                 *bandwidth = 0;
365
366         if (*bandwidth == 0)
367                 return;
368
369         ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
370         if (ret < 0)
371                 *bandwidth = 0;
372
373         if (allocate && ret < 0) {
374                 if (c >= 0)
375                         deallocate_channel(card, irm_id, generation, c);
376                 *channel = ret;
377         }
378 }
379 EXPORT_SYMBOL(fw_iso_resource_manage);