2 * Isochronous I/O functionality:
3 * - Isochronous DMA context management
4 * - Isochronous bus resource management (channels, bandwidth), client side
6 * Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net>
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.
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.
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.
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>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/vmalloc.h>
33 #include <asm/byteorder.h>
38 * Isochronous DMA context management
41 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card,
42 int page_count, enum dma_data_direction direction)
47 buffer->page_count = page_count;
48 buffer->direction = direction;
50 buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]),
52 if (buffer->pages == NULL)
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)
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]);
66 set_page_private(buffer->pages[i], address);
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]);
84 EXPORT_SYMBOL(fw_iso_buffer_init);
86 int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma)
91 uaddr = vma->vm_start;
92 for (i = 0; i < buffer->page_count; i++) {
93 err = vm_insert_page(vma, uaddr, buffer->pages[i]);
103 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer,
104 struct fw_card *card)
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]);
116 kfree(buffer->pages);
117 buffer->pages = NULL;
119 EXPORT_SYMBOL(fw_iso_buffer_destroy);
121 /* Convert DMA address to offset into virtually contiguous buffer. */
122 size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed)
128 for (i = 0; i < buffer->page_count; i++) {
129 address = page_private(buffer->pages[i]);
130 offset = (ssize_t)completed - (ssize_t)address;
131 if (offset > 0 && offset <= PAGE_SIZE)
132 return (i << PAGE_SHIFT) + offset;
138 struct fw_iso_context *fw_iso_context_create(struct fw_card *card,
139 int type, int channel, int speed, size_t header_size,
140 fw_iso_callback_t callback, void *callback_data)
142 struct fw_iso_context *ctx;
144 ctx = card->driver->allocate_iso_context(card,
145 type, channel, header_size);
151 ctx->channel = channel;
153 ctx->header_size = header_size;
154 ctx->callback.sc = callback;
155 ctx->callback_data = callback_data;
159 EXPORT_SYMBOL(fw_iso_context_create);
161 void fw_iso_context_destroy(struct fw_iso_context *ctx)
163 ctx->card->driver->free_iso_context(ctx);
165 EXPORT_SYMBOL(fw_iso_context_destroy);
167 int fw_iso_context_start(struct fw_iso_context *ctx,
168 int cycle, int sync, int tags)
170 return ctx->card->driver->start_iso(ctx, cycle, sync, tags);
172 EXPORT_SYMBOL(fw_iso_context_start);
174 int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels)
176 return ctx->card->driver->set_iso_channels(ctx, channels);
179 int fw_iso_context_queue(struct fw_iso_context *ctx,
180 struct fw_iso_packet *packet,
181 struct fw_iso_buffer *buffer,
182 unsigned long payload)
184 return ctx->card->driver->queue_iso(ctx, packet, buffer, payload);
186 EXPORT_SYMBOL(fw_iso_context_queue);
188 int fw_iso_context_stop(struct fw_iso_context *ctx)
190 return ctx->card->driver->stop_iso(ctx);
192 EXPORT_SYMBOL(fw_iso_context_stop);
195 * Isochronous bus resource management (channels, bandwidth), client side
198 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,
199 int bandwidth, bool allocate)
201 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;
205 * On a 1394a IRM with low contention, try < 1 is enough.
206 * On a 1394-1995 IRM, we need at least try < 2.
207 * Let's just do try < 5.
209 for (try = 0; try < 5; try++) {
210 new = allocate ? old - bandwidth : old + bandwidth;
211 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL)
214 data[0] = cpu_to_be32(old);
215 data[1] = cpu_to_be32(new);
216 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
217 irm_id, generation, SCODE_100,
218 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,
220 case RCODE_GENERATION:
221 /* A generation change frees all bandwidth. */
222 return allocate ? -EAGAIN : bandwidth;
225 if (be32_to_cpup(data) == old)
228 old = be32_to_cpup(data);
236 static int manage_channel(struct fw_card *card, int irm_id, int generation,
237 u32 channels_mask, u64 offset, bool allocate)
239 __be32 bit, all, old;
241 int channel, ret = -EIO, retry = 5;
243 old = all = allocate ? cpu_to_be32(~0) : 0;
245 for (channel = 0; channel < 32; channel++) {
246 if (!(channels_mask & 1 << channel))
251 bit = cpu_to_be32(1 << (31 - channel));
252 if ((old & bit) != (all & bit))
257 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,
258 irm_id, generation, SCODE_100,
260 case RCODE_GENERATION:
261 /* A generation change frees all channels. */
262 return allocate ? -EAGAIN : channel;
270 /* Is the IRM 1394a-2000 compliant? */
271 if ((data[0] & bit) == (data[1] & bit))
274 /* 1394-1995 IRM, fall through to retry. */
288 static void deallocate_channel(struct fw_card *card, int irm_id,
289 int generation, int channel)
294 mask = channel < 32 ? 1 << channel : 1 << (channel - 32);
295 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :
296 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;
298 manage_channel(card, irm_id, generation, mask, offset, false);
302 * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth
304 * In parameters: card, generation, channels_mask, bandwidth, allocate
305 * Out parameters: channel, bandwidth
306 * This function blocks (sleeps) during communication with the IRM.
308 * Allocates or deallocates at most one channel out of channels_mask.
309 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.
310 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for
311 * channel 0 and LSB for channel 63.)
312 * Allocates or deallocates as many bandwidth allocation units as specified.
314 * Returns channel < 0 if no channel was allocated or deallocated.
315 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.
317 * If generation is stale, deallocations succeed but allocations fail with
320 * If channel allocation fails, no bandwidth will be allocated either.
321 * If bandwidth allocation fails, no channel will be allocated either.
322 * But deallocations of channel and bandwidth are tried independently
323 * of each other's success.
325 void fw_iso_resource_manage(struct fw_card *card, int generation,
326 u64 channels_mask, int *channel, int *bandwidth,
329 u32 channels_hi = channels_mask; /* channels 31...0 */
330 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */
331 int irm_id, ret, c = -EINVAL;
333 spin_lock_irq(&card->lock);
334 irm_id = card->irm_node->node_id;
335 spin_unlock_irq(&card->lock);
338 c = manage_channel(card, irm_id, generation, channels_hi,
339 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,
341 if (channels_lo && c < 0) {
342 c = manage_channel(card, irm_id, generation, channels_lo,
343 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,
350 if (allocate && channels_mask != 0 && c < 0)
356 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);
360 if (allocate && ret < 0) {
362 deallocate_channel(card, irm_id, generation, c);
366 EXPORT_SYMBOL(fw_iso_resource_manage);