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 /* 26 * Isochronous DMA context management 27 */ 28 29 int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count) 30 { 31 int i; 32 33 buffer->page_count = 0; 34 buffer->page_count_mapped = 0; 35 buffer->pages = kmalloc_array(page_count, sizeof(buffer->pages[0]), 36 GFP_KERNEL); 37 if (buffer->pages == NULL) 38 return -ENOMEM; 39 40 for (i = 0; i < page_count; i++) { 41 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO); 42 if (buffer->pages[i] == NULL) 43 break; 44 } 45 buffer->page_count = i; 46 if (i < page_count) { 47 fw_iso_buffer_destroy(buffer, NULL); 48 return -ENOMEM; 49 } 50 51 return 0; 52 } 53 54 int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card, 55 enum dma_data_direction direction) 56 { 57 dma_addr_t address; 58 int i; 59 60 buffer->direction = direction; 61 62 for (i = 0; i < buffer->page_count; i++) { 63 address = dma_map_page(card->device, buffer->pages[i], 64 0, PAGE_SIZE, direction); 65 if (dma_mapping_error(card->device, address)) 66 break; 67 68 set_page_private(buffer->pages[i], address); 69 } 70 buffer->page_count_mapped = i; 71 if (i < buffer->page_count) 72 return -ENOMEM; 73 74 return 0; 75 } 76 77 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, 78 int page_count, enum dma_data_direction direction) 79 { 80 int ret; 81 82 ret = fw_iso_buffer_alloc(buffer, page_count); 83 if (ret < 0) 84 return ret; 85 86 ret = fw_iso_buffer_map_dma(buffer, card, direction); 87 if (ret < 0) 88 fw_iso_buffer_destroy(buffer, card); 89 90 return ret; 91 } 92 EXPORT_SYMBOL(fw_iso_buffer_init); 93 94 int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer, 95 struct vm_area_struct *vma) 96 { 97 return vm_map_pages_zero(vma, buffer->pages, 98 buffer->page_count); 99 } 100 101 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, 102 struct fw_card *card) 103 { 104 int i; 105 dma_addr_t address; 106 107 for (i = 0; i < buffer->page_count_mapped; i++) { 108 address = page_private(buffer->pages[i]); 109 dma_unmap_page(card->device, address, 110 PAGE_SIZE, buffer->direction); 111 } 112 for (i = 0; i < buffer->page_count; i++) 113 __free_page(buffer->pages[i]); 114 115 kfree(buffer->pages); 116 buffer->pages = NULL; 117 buffer->page_count = 0; 118 buffer->page_count_mapped = 0; 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 size_t 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 /* fall through - It's a 1394-1995 IRM, 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 * @card: card interface for this action 317 * @generation: bus generation 318 * @channels_mask: bitmask for channel allocation 319 * @channel: pointer for returning channel allocation result 320 * @bandwidth: pointer for returning bandwidth allocation result 321 * @allocate: whether to allocate (true) or deallocate (false) 322 * 323 * In parameters: card, generation, channels_mask, bandwidth, allocate 324 * Out parameters: channel, bandwidth 325 * 326 * This function blocks (sleeps) during communication with the IRM. 327 * 328 * Allocates or deallocates at most one channel out of channels_mask. 329 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0. 330 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for 331 * channel 0 and LSB for channel 63.) 332 * Allocates or deallocates as many bandwidth allocation units as specified. 333 * 334 * Returns channel < 0 if no channel was allocated or deallocated. 335 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. 336 * 337 * If generation is stale, deallocations succeed but allocations fail with 338 * channel = -EAGAIN. 339 * 340 * If channel allocation fails, no bandwidth will be allocated either. 341 * If bandwidth allocation fails, no channel will be allocated either. 342 * But deallocations of channel and bandwidth are tried independently 343 * of each other's success. 344 */ 345 void fw_iso_resource_manage(struct fw_card *card, int generation, 346 u64 channels_mask, int *channel, int *bandwidth, 347 bool allocate) 348 { 349 u32 channels_hi = channels_mask; /* channels 31...0 */ 350 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */ 351 int irm_id, ret, c = -EINVAL; 352 353 spin_lock_irq(&card->lock); 354 irm_id = card->irm_node->node_id; 355 spin_unlock_irq(&card->lock); 356 357 if (channels_hi) 358 c = manage_channel(card, irm_id, generation, channels_hi, 359 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, 360 allocate); 361 if (channels_lo && c < 0) { 362 c = manage_channel(card, irm_id, generation, channels_lo, 363 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, 364 allocate); 365 if (c >= 0) 366 c += 32; 367 } 368 *channel = c; 369 370 if (allocate && channels_mask != 0 && c < 0) 371 *bandwidth = 0; 372 373 if (*bandwidth == 0) 374 return; 375 376 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate); 377 if (ret < 0) 378 *bandwidth = 0; 379 380 if (allocate && ret < 0) { 381 if (c >= 0) 382 deallocate_channel(card, irm_id, generation, c); 383 *channel = ret; 384 } 385 } 386 EXPORT_SYMBOL(fw_iso_resource_manage); 387