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