1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Isochronous I/O functionality: 4 * - Isochronous DMA context management 5 * - Isochronous bus resource management (channels, bandwidth), client side 6 * 7 * Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net> 8 */ 9 10 #include <linux/dma-mapping.h> 11 #include <linux/errno.h> 12 #include <linux/firewire.h> 13 #include <linux/firewire-constants.h> 14 #include <linux/kernel.h> 15 #include <linux/mm.h> 16 #include <linux/slab.h> 17 #include <linux/spinlock.h> 18 #include <linux/vmalloc.h> 19 #include <linux/export.h> 20 21 #include <asm/byteorder.h> 22 23 #include "core.h" 24 25 #include <trace/events/firewire.h> 26 27 /* 28 * Isochronous DMA context management 29 */ 30 31 int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count) 32 { 33 int i; 34 35 buffer->page_count = 0; 36 buffer->page_count_mapped = 0; 37 buffer->pages = kmalloc_array(page_count, sizeof(buffer->pages[0]), 38 GFP_KERNEL); 39 if (buffer->pages == NULL) 40 return -ENOMEM; 41 42 for (i = 0; i < page_count; i++) { 43 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO); 44 if (buffer->pages[i] == NULL) 45 break; 46 } 47 buffer->page_count = i; 48 if (i < page_count) { 49 fw_iso_buffer_destroy(buffer, NULL); 50 return -ENOMEM; 51 } 52 53 return 0; 54 } 55 56 int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card, 57 enum dma_data_direction direction) 58 { 59 dma_addr_t address; 60 int i; 61 62 buffer->direction = direction; 63 64 for (i = 0; i < buffer->page_count; i++) { 65 address = dma_map_page(card->device, buffer->pages[i], 66 0, PAGE_SIZE, direction); 67 if (dma_mapping_error(card->device, address)) 68 break; 69 70 set_page_private(buffer->pages[i], address); 71 } 72 buffer->page_count_mapped = i; 73 if (i < buffer->page_count) 74 return -ENOMEM; 75 76 return 0; 77 } 78 79 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, 80 int page_count, enum dma_data_direction direction) 81 { 82 int ret; 83 84 ret = fw_iso_buffer_alloc(buffer, page_count); 85 if (ret < 0) 86 return ret; 87 88 ret = fw_iso_buffer_map_dma(buffer, card, direction); 89 if (ret < 0) 90 fw_iso_buffer_destroy(buffer, card); 91 92 return ret; 93 } 94 EXPORT_SYMBOL(fw_iso_buffer_init); 95 96 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, 97 struct fw_card *card) 98 { 99 int i; 100 dma_addr_t address; 101 102 for (i = 0; i < buffer->page_count_mapped; i++) { 103 address = page_private(buffer->pages[i]); 104 dma_unmap_page(card->device, address, 105 PAGE_SIZE, buffer->direction); 106 } 107 for (i = 0; i < buffer->page_count; i++) 108 __free_page(buffer->pages[i]); 109 110 kfree(buffer->pages); 111 buffer->pages = NULL; 112 buffer->page_count = 0; 113 buffer->page_count_mapped = 0; 114 } 115 EXPORT_SYMBOL(fw_iso_buffer_destroy); 116 117 /* Convert DMA address to offset into virtually contiguous buffer. */ 118 size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed) 119 { 120 size_t i; 121 dma_addr_t address; 122 ssize_t offset; 123 124 for (i = 0; i < buffer->page_count; i++) { 125 address = page_private(buffer->pages[i]); 126 offset = (ssize_t)completed - (ssize_t)address; 127 if (offset > 0 && offset <= PAGE_SIZE) 128 return (i << PAGE_SHIFT) + offset; 129 } 130 131 return 0; 132 } 133 134 struct fw_iso_context *fw_iso_context_create(struct fw_card *card, 135 int type, int channel, int speed, size_t header_size, 136 fw_iso_callback_t callback, void *callback_data) 137 { 138 struct fw_iso_context *ctx; 139 140 ctx = card->driver->allocate_iso_context(card, 141 type, channel, header_size); 142 if (IS_ERR(ctx)) 143 return ctx; 144 145 ctx->card = card; 146 ctx->type = type; 147 ctx->channel = channel; 148 ctx->speed = speed; 149 ctx->header_size = header_size; 150 ctx->callback.sc = callback; 151 ctx->callback_data = callback_data; 152 153 trace_isoc_outbound_allocate(ctx, channel, speed); 154 trace_isoc_inbound_single_allocate(ctx, channel, header_size); 155 trace_isoc_inbound_multiple_allocate(ctx); 156 157 return ctx; 158 } 159 EXPORT_SYMBOL(fw_iso_context_create); 160 161 void fw_iso_context_destroy(struct fw_iso_context *ctx) 162 { 163 trace_isoc_outbound_destroy(ctx); 164 trace_isoc_inbound_single_destroy(ctx); 165 trace_isoc_inbound_multiple_destroy(ctx); 166 167 ctx->card->driver->free_iso_context(ctx); 168 } 169 EXPORT_SYMBOL(fw_iso_context_destroy); 170 171 int fw_iso_context_start(struct fw_iso_context *ctx, 172 int cycle, int sync, int tags) 173 { 174 trace_isoc_outbound_start(ctx, cycle); 175 trace_isoc_inbound_single_start(ctx, cycle, sync, tags); 176 trace_isoc_inbound_multiple_start(ctx, cycle, sync, tags); 177 178 return ctx->card->driver->start_iso(ctx, cycle, sync, tags); 179 } 180 EXPORT_SYMBOL(fw_iso_context_start); 181 182 int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels) 183 { 184 trace_isoc_inbound_multiple_channels(ctx, *channels); 185 186 return ctx->card->driver->set_iso_channels(ctx, channels); 187 } 188 189 int fw_iso_context_queue(struct fw_iso_context *ctx, 190 struct fw_iso_packet *packet, 191 struct fw_iso_buffer *buffer, 192 unsigned long payload) 193 { 194 trace_isoc_outbound_queue(ctx, payload, packet); 195 trace_isoc_inbound_single_queue(ctx, payload, packet); 196 trace_isoc_inbound_multiple_queue(ctx, payload, packet); 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 trace_isoc_outbound_flush(ctx); 205 trace_isoc_inbound_single_flush(ctx); 206 trace_isoc_inbound_multiple_flush(ctx); 207 208 ctx->card->driver->flush_queue_iso(ctx); 209 } 210 EXPORT_SYMBOL(fw_iso_context_queue_flush); 211 212 int fw_iso_context_flush_completions(struct fw_iso_context *ctx) 213 { 214 int err; 215 216 trace_isoc_outbound_flush_completions(ctx); 217 trace_isoc_inbound_single_flush_completions(ctx); 218 trace_isoc_inbound_multiple_flush_completions(ctx); 219 220 might_sleep(); 221 222 // Avoid dead lock due to programming mistake. 223 if (WARN_ON(current_work() == &ctx->work)) 224 return 0; 225 226 disable_work_sync(&ctx->work); 227 228 err = ctx->card->driver->flush_iso_completions(ctx); 229 230 enable_work(&ctx->work); 231 232 return err; 233 } 234 EXPORT_SYMBOL(fw_iso_context_flush_completions); 235 236 int fw_iso_context_stop(struct fw_iso_context *ctx) 237 { 238 int err; 239 240 trace_isoc_outbound_stop(ctx); 241 trace_isoc_inbound_single_stop(ctx); 242 trace_isoc_inbound_multiple_stop(ctx); 243 244 might_sleep(); 245 246 // Avoid dead lock due to programming mistake. 247 if (WARN_ON(current_work() == &ctx->work)) 248 return 0; 249 250 err = ctx->card->driver->stop_iso(ctx); 251 252 cancel_work_sync(&ctx->work); 253 254 return err; 255 } 256 EXPORT_SYMBOL(fw_iso_context_stop); 257 258 /* 259 * Isochronous bus resource management (channels, bandwidth), client side 260 */ 261 262 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation, 263 int bandwidth, bool allocate) 264 { 265 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0; 266 __be32 data[2]; 267 268 /* 269 * On a 1394a IRM with low contention, try < 1 is enough. 270 * On a 1394-1995 IRM, we need at least try < 2. 271 * Let's just do try < 5. 272 */ 273 for (try = 0; try < 5; try++) { 274 new = allocate ? old - bandwidth : old + bandwidth; 275 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL) 276 return -EBUSY; 277 278 data[0] = cpu_to_be32(old); 279 data[1] = cpu_to_be32(new); 280 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, 281 irm_id, generation, SCODE_100, 282 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE, 283 data, 8)) { 284 case RCODE_GENERATION: 285 /* A generation change frees all bandwidth. */ 286 return allocate ? -EAGAIN : bandwidth; 287 288 case RCODE_COMPLETE: 289 if (be32_to_cpup(data) == old) 290 return bandwidth; 291 292 old = be32_to_cpup(data); 293 /* Fall through. */ 294 } 295 } 296 297 return -EIO; 298 } 299 300 static int manage_channel(struct fw_card *card, int irm_id, int generation, 301 u32 channels_mask, u64 offset, bool allocate) 302 { 303 __be32 bit, all, old; 304 __be32 data[2]; 305 int channel, ret = -EIO, retry = 5; 306 307 old = all = allocate ? cpu_to_be32(~0) : 0; 308 309 for (channel = 0; channel < 32; channel++) { 310 if (!(channels_mask & 1 << channel)) 311 continue; 312 313 ret = -EBUSY; 314 315 bit = cpu_to_be32(1 << (31 - channel)); 316 if ((old & bit) != (all & bit)) 317 continue; 318 319 data[0] = old; 320 data[1] = old ^ bit; 321 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, 322 irm_id, generation, SCODE_100, 323 offset, data, 8)) { 324 case RCODE_GENERATION: 325 /* A generation change frees all channels. */ 326 return allocate ? -EAGAIN : channel; 327 328 case RCODE_COMPLETE: 329 if (data[0] == old) 330 return channel; 331 332 old = data[0]; 333 334 /* Is the IRM 1394a-2000 compliant? */ 335 if ((data[0] & bit) == (data[1] & bit)) 336 continue; 337 338 fallthrough; /* It's a 1394-1995 IRM, retry */ 339 default: 340 if (retry) { 341 retry--; 342 channel--; 343 } else { 344 ret = -EIO; 345 } 346 } 347 } 348 349 return ret; 350 } 351 352 static void deallocate_channel(struct fw_card *card, int irm_id, 353 int generation, int channel) 354 { 355 u32 mask; 356 u64 offset; 357 358 mask = channel < 32 ? 1 << channel : 1 << (channel - 32); 359 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI : 360 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO; 361 362 manage_channel(card, irm_id, generation, mask, offset, false); 363 } 364 365 /** 366 * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth 367 * @card: card interface for this action 368 * @generation: bus generation 369 * @channels_mask: bitmask for channel allocation 370 * @channel: pointer for returning channel allocation result 371 * @bandwidth: pointer for returning bandwidth allocation result 372 * @allocate: whether to allocate (true) or deallocate (false) 373 * 374 * In parameters: card, generation, channels_mask, bandwidth, allocate 375 * Out parameters: channel, bandwidth 376 * 377 * This function blocks (sleeps) during communication with the IRM. 378 * 379 * Allocates or deallocates at most one channel out of channels_mask. 380 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0. 381 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for 382 * channel 0 and LSB for channel 63.) 383 * Allocates or deallocates as many bandwidth allocation units as specified. 384 * 385 * Returns channel < 0 if no channel was allocated or deallocated. 386 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. 387 * 388 * If generation is stale, deallocations succeed but allocations fail with 389 * channel = -EAGAIN. 390 * 391 * If channel allocation fails, no bandwidth will be allocated either. 392 * If bandwidth allocation fails, no channel will be allocated either. 393 * But deallocations of channel and bandwidth are tried independently 394 * of each other's success. 395 */ 396 void fw_iso_resource_manage(struct fw_card *card, int generation, 397 u64 channels_mask, int *channel, int *bandwidth, 398 bool allocate) 399 { 400 u32 channels_hi = channels_mask; /* channels 31...0 */ 401 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */ 402 int irm_id, ret, c = -EINVAL; 403 404 scoped_guard(spinlock_irq, &card->lock) 405 irm_id = card->irm_node->node_id; 406 407 if (channels_hi) 408 c = manage_channel(card, irm_id, generation, channels_hi, 409 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, 410 allocate); 411 if (channels_lo && c < 0) { 412 c = manage_channel(card, irm_id, generation, channels_lo, 413 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, 414 allocate); 415 if (c >= 0) 416 c += 32; 417 } 418 *channel = c; 419 420 if (allocate && channels_mask != 0 && c < 0) 421 *bandwidth = 0; 422 423 if (*bandwidth == 0) 424 return; 425 426 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate); 427 if (ret < 0) 428 *bandwidth = 0; 429 430 if (allocate && ret < 0) { 431 if (c >= 0) 432 deallocate_channel(card, irm_id, generation, c); 433 *channel = ret; 434 } 435 } 436 EXPORT_SYMBOL(fw_iso_resource_manage); 437