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_alloc(struct fw_iso_buffer *buffer, int page_count) 43 { 44 int i; 45 46 buffer->page_count = 0; 47 buffer->page_count_mapped = 0; 48 buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]), 49 GFP_KERNEL); 50 if (buffer->pages == NULL) 51 return -ENOMEM; 52 53 for (i = 0; i < page_count; i++) { 54 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO); 55 if (buffer->pages[i] == NULL) 56 break; 57 } 58 buffer->page_count = i; 59 if (i < page_count) { 60 fw_iso_buffer_destroy(buffer, NULL); 61 return -ENOMEM; 62 } 63 64 return 0; 65 } 66 67 int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card, 68 enum dma_data_direction direction) 69 { 70 dma_addr_t address; 71 int i; 72 73 buffer->direction = direction; 74 75 for (i = 0; i < buffer->page_count; i++) { 76 address = dma_map_page(card->device, buffer->pages[i], 77 0, PAGE_SIZE, direction); 78 if (dma_mapping_error(card->device, address)) 79 break; 80 81 set_page_private(buffer->pages[i], address); 82 } 83 buffer->page_count_mapped = i; 84 if (i < buffer->page_count) 85 return -ENOMEM; 86 87 return 0; 88 } 89 90 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, 91 int page_count, enum dma_data_direction direction) 92 { 93 int ret; 94 95 ret = fw_iso_buffer_alloc(buffer, page_count); 96 if (ret < 0) 97 return ret; 98 99 ret = fw_iso_buffer_map_dma(buffer, card, direction); 100 if (ret < 0) 101 fw_iso_buffer_destroy(buffer, card); 102 103 return ret; 104 } 105 EXPORT_SYMBOL(fw_iso_buffer_init); 106 107 int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer, 108 struct vm_area_struct *vma) 109 { 110 unsigned long uaddr; 111 int i, err; 112 113 uaddr = vma->vm_start; 114 for (i = 0; i < buffer->page_count; i++) { 115 err = vm_insert_page(vma, uaddr, buffer->pages[i]); 116 if (err) 117 return err; 118 119 uaddr += PAGE_SIZE; 120 } 121 122 return 0; 123 } 124 125 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, 126 struct fw_card *card) 127 { 128 int i; 129 dma_addr_t address; 130 131 for (i = 0; i < buffer->page_count_mapped; i++) { 132 address = page_private(buffer->pages[i]); 133 dma_unmap_page(card->device, address, 134 PAGE_SIZE, buffer->direction); 135 } 136 for (i = 0; i < buffer->page_count; i++) 137 __free_page(buffer->pages[i]); 138 139 kfree(buffer->pages); 140 buffer->pages = NULL; 141 buffer->page_count = 0; 142 buffer->page_count_mapped = 0; 143 } 144 EXPORT_SYMBOL(fw_iso_buffer_destroy); 145 146 /* Convert DMA address to offset into virtually contiguous buffer. */ 147 size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed) 148 { 149 size_t i; 150 dma_addr_t address; 151 ssize_t offset; 152 153 for (i = 0; i < buffer->page_count; i++) { 154 address = page_private(buffer->pages[i]); 155 offset = (ssize_t)completed - (ssize_t)address; 156 if (offset > 0 && offset <= PAGE_SIZE) 157 return (i << PAGE_SHIFT) + offset; 158 } 159 160 return 0; 161 } 162 163 struct fw_iso_context *fw_iso_context_create(struct fw_card *card, 164 int type, int channel, int speed, size_t header_size, 165 fw_iso_callback_t callback, void *callback_data) 166 { 167 struct fw_iso_context *ctx; 168 169 ctx = card->driver->allocate_iso_context(card, 170 type, channel, header_size); 171 if (IS_ERR(ctx)) 172 return ctx; 173 174 ctx->card = card; 175 ctx->type = type; 176 ctx->channel = channel; 177 ctx->speed = speed; 178 ctx->header_size = header_size; 179 ctx->callback.sc = callback; 180 ctx->callback_data = callback_data; 181 182 return ctx; 183 } 184 EXPORT_SYMBOL(fw_iso_context_create); 185 186 void fw_iso_context_destroy(struct fw_iso_context *ctx) 187 { 188 ctx->card->driver->free_iso_context(ctx); 189 } 190 EXPORT_SYMBOL(fw_iso_context_destroy); 191 192 int fw_iso_context_start(struct fw_iso_context *ctx, 193 int cycle, int sync, int tags) 194 { 195 return ctx->card->driver->start_iso(ctx, cycle, sync, tags); 196 } 197 EXPORT_SYMBOL(fw_iso_context_start); 198 199 int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels) 200 { 201 return ctx->card->driver->set_iso_channels(ctx, channels); 202 } 203 204 int fw_iso_context_queue(struct fw_iso_context *ctx, 205 struct fw_iso_packet *packet, 206 struct fw_iso_buffer *buffer, 207 unsigned long payload) 208 { 209 return ctx->card->driver->queue_iso(ctx, packet, buffer, payload); 210 } 211 EXPORT_SYMBOL(fw_iso_context_queue); 212 213 void fw_iso_context_queue_flush(struct fw_iso_context *ctx) 214 { 215 ctx->card->driver->flush_queue_iso(ctx); 216 } 217 EXPORT_SYMBOL(fw_iso_context_queue_flush); 218 219 int fw_iso_context_flush_completions(struct fw_iso_context *ctx) 220 { 221 return ctx->card->driver->flush_iso_completions(ctx); 222 } 223 EXPORT_SYMBOL(fw_iso_context_flush_completions); 224 225 int fw_iso_context_stop(struct fw_iso_context *ctx) 226 { 227 return ctx->card->driver->stop_iso(ctx); 228 } 229 EXPORT_SYMBOL(fw_iso_context_stop); 230 231 /* 232 * Isochronous bus resource management (channels, bandwidth), client side 233 */ 234 235 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation, 236 int bandwidth, bool allocate) 237 { 238 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0; 239 __be32 data[2]; 240 241 /* 242 * On a 1394a IRM with low contention, try < 1 is enough. 243 * On a 1394-1995 IRM, we need at least try < 2. 244 * Let's just do try < 5. 245 */ 246 for (try = 0; try < 5; try++) { 247 new = allocate ? old - bandwidth : old + bandwidth; 248 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL) 249 return -EBUSY; 250 251 data[0] = cpu_to_be32(old); 252 data[1] = cpu_to_be32(new); 253 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, 254 irm_id, generation, SCODE_100, 255 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE, 256 data, 8)) { 257 case RCODE_GENERATION: 258 /* A generation change frees all bandwidth. */ 259 return allocate ? -EAGAIN : bandwidth; 260 261 case RCODE_COMPLETE: 262 if (be32_to_cpup(data) == old) 263 return bandwidth; 264 265 old = be32_to_cpup(data); 266 /* Fall through. */ 267 } 268 } 269 270 return -EIO; 271 } 272 273 static int manage_channel(struct fw_card *card, int irm_id, int generation, 274 u32 channels_mask, u64 offset, bool allocate) 275 { 276 __be32 bit, all, old; 277 __be32 data[2]; 278 int channel, ret = -EIO, retry = 5; 279 280 old = all = allocate ? cpu_to_be32(~0) : 0; 281 282 for (channel = 0; channel < 32; channel++) { 283 if (!(channels_mask & 1 << channel)) 284 continue; 285 286 ret = -EBUSY; 287 288 bit = cpu_to_be32(1 << (31 - channel)); 289 if ((old & bit) != (all & bit)) 290 continue; 291 292 data[0] = old; 293 data[1] = old ^ bit; 294 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, 295 irm_id, generation, SCODE_100, 296 offset, data, 8)) { 297 case RCODE_GENERATION: 298 /* A generation change frees all channels. */ 299 return allocate ? -EAGAIN : channel; 300 301 case RCODE_COMPLETE: 302 if (data[0] == old) 303 return channel; 304 305 old = data[0]; 306 307 /* Is the IRM 1394a-2000 compliant? */ 308 if ((data[0] & bit) == (data[1] & bit)) 309 continue; 310 311 /* 1394-1995 IRM, fall through to retry. */ 312 default: 313 if (retry) { 314 retry--; 315 channel--; 316 } else { 317 ret = -EIO; 318 } 319 } 320 } 321 322 return ret; 323 } 324 325 static void deallocate_channel(struct fw_card *card, int irm_id, 326 int generation, int channel) 327 { 328 u32 mask; 329 u64 offset; 330 331 mask = channel < 32 ? 1 << channel : 1 << (channel - 32); 332 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI : 333 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO; 334 335 manage_channel(card, irm_id, generation, mask, offset, false); 336 } 337 338 /** 339 * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth 340 * 341 * In parameters: card, generation, channels_mask, bandwidth, allocate 342 * Out parameters: channel, bandwidth 343 * This function blocks (sleeps) during communication with the IRM. 344 * 345 * Allocates or deallocates at most one channel out of channels_mask. 346 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0. 347 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for 348 * channel 0 and LSB for channel 63.) 349 * Allocates or deallocates as many bandwidth allocation units as specified. 350 * 351 * Returns channel < 0 if no channel was allocated or deallocated. 352 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. 353 * 354 * If generation is stale, deallocations succeed but allocations fail with 355 * channel = -EAGAIN. 356 * 357 * If channel allocation fails, no bandwidth will be allocated either. 358 * If bandwidth allocation fails, no channel will be allocated either. 359 * But deallocations of channel and bandwidth are tried independently 360 * of each other's success. 361 */ 362 void fw_iso_resource_manage(struct fw_card *card, int generation, 363 u64 channels_mask, int *channel, int *bandwidth, 364 bool allocate) 365 { 366 u32 channels_hi = channels_mask; /* channels 31...0 */ 367 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */ 368 int irm_id, ret, c = -EINVAL; 369 370 spin_lock_irq(&card->lock); 371 irm_id = card->irm_node->node_id; 372 spin_unlock_irq(&card->lock); 373 374 if (channels_hi) 375 c = manage_channel(card, irm_id, generation, channels_hi, 376 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, 377 allocate); 378 if (channels_lo && c < 0) { 379 c = manage_channel(card, irm_id, generation, channels_lo, 380 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, 381 allocate); 382 if (c >= 0) 383 c += 32; 384 } 385 *channel = c; 386 387 if (allocate && channels_mask != 0 && c < 0) 388 *bandwidth = 0; 389 390 if (*bandwidth == 0) 391 return; 392 393 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate); 394 if (ret < 0) 395 *bandwidth = 0; 396 397 if (allocate && ret < 0) { 398 if (c >= 0) 399 deallocate_channel(card, irm_id, generation, c); 400 *channel = ret; 401 } 402 } 403 EXPORT_SYMBOL(fw_iso_resource_manage); 404