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 33 #include <asm/byteorder.h> 34 35 #include "core.h" 36 37 /* 38 * Isochronous DMA context management 39 */ 40 41 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, 42 int page_count, enum dma_data_direction direction) 43 { 44 int i, j; 45 dma_addr_t address; 46 47 buffer->page_count = page_count; 48 buffer->direction = direction; 49 50 buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]), 51 GFP_KERNEL); 52 if (buffer->pages == NULL) 53 goto out; 54 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) 58 goto out_pages; 59 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]); 64 goto out_pages; 65 } 66 set_page_private(buffer->pages[i], address); 67 } 68 69 return 0; 70 71 out_pages: 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]); 77 } 78 kfree(buffer->pages); 79 out: 80 buffer->pages = NULL; 81 82 return -ENOMEM; 83 } 84 EXPORT_SYMBOL(fw_iso_buffer_init); 85 86 int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma) 87 { 88 unsigned long uaddr; 89 int i, err; 90 91 uaddr = vma->vm_start; 92 for (i = 0; i < buffer->page_count; i++) { 93 err = vm_insert_page(vma, uaddr, buffer->pages[i]); 94 if (err) 95 return err; 96 97 uaddr += PAGE_SIZE; 98 } 99 100 return 0; 101 } 102 103 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, 104 struct fw_card *card) 105 { 106 int i; 107 dma_addr_t address; 108 109 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]); 114 } 115 116 kfree(buffer->pages); 117 buffer->pages = NULL; 118 } 119 EXPORT_SYMBOL(fw_iso_buffer_destroy); 120 121 struct fw_iso_context *fw_iso_context_create(struct fw_card *card, 122 int type, int channel, int speed, size_t header_size, 123 fw_iso_callback_t callback, void *callback_data) 124 { 125 struct fw_iso_context *ctx; 126 127 ctx = card->driver->allocate_iso_context(card, 128 type, channel, header_size); 129 if (IS_ERR(ctx)) 130 return ctx; 131 132 ctx->card = card; 133 ctx->type = type; 134 ctx->channel = channel; 135 ctx->speed = speed; 136 ctx->header_size = header_size; 137 ctx->callback = callback; 138 ctx->callback_data = callback_data; 139 140 return ctx; 141 } 142 EXPORT_SYMBOL(fw_iso_context_create); 143 144 void fw_iso_context_destroy(struct fw_iso_context *ctx) 145 { 146 struct fw_card *card = ctx->card; 147 148 card->driver->free_iso_context(ctx); 149 } 150 EXPORT_SYMBOL(fw_iso_context_destroy); 151 152 int fw_iso_context_start(struct fw_iso_context *ctx, 153 int cycle, int sync, int tags) 154 { 155 return ctx->card->driver->start_iso(ctx, cycle, sync, tags); 156 } 157 EXPORT_SYMBOL(fw_iso_context_start); 158 159 int fw_iso_context_queue(struct fw_iso_context *ctx, 160 struct fw_iso_packet *packet, 161 struct fw_iso_buffer *buffer, 162 unsigned long payload) 163 { 164 struct fw_card *card = ctx->card; 165 166 return card->driver->queue_iso(ctx, packet, buffer, payload); 167 } 168 EXPORT_SYMBOL(fw_iso_context_queue); 169 170 int fw_iso_context_stop(struct fw_iso_context *ctx) 171 { 172 return ctx->card->driver->stop_iso(ctx); 173 } 174 EXPORT_SYMBOL(fw_iso_context_stop); 175 176 /* 177 * Isochronous bus resource management (channels, bandwidth), client side 178 */ 179 180 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation, 181 int bandwidth, bool allocate, __be32 data[2]) 182 { 183 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0; 184 185 /* 186 * On a 1394a IRM with low contention, try < 1 is enough. 187 * On a 1394-1995 IRM, we need at least try < 2. 188 * Let's just do try < 5. 189 */ 190 for (try = 0; try < 5; try++) { 191 new = allocate ? old - bandwidth : old + bandwidth; 192 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL) 193 return -EBUSY; 194 195 data[0] = cpu_to_be32(old); 196 data[1] = cpu_to_be32(new); 197 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, 198 irm_id, generation, SCODE_100, 199 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE, 200 data, 8)) { 201 case RCODE_GENERATION: 202 /* A generation change frees all bandwidth. */ 203 return allocate ? -EAGAIN : bandwidth; 204 205 case RCODE_COMPLETE: 206 if (be32_to_cpup(data) == old) 207 return bandwidth; 208 209 old = be32_to_cpup(data); 210 /* Fall through. */ 211 } 212 } 213 214 return -EIO; 215 } 216 217 static int manage_channel(struct fw_card *card, int irm_id, int generation, 218 u32 channels_mask, u64 offset, bool allocate, __be32 data[2]) 219 { 220 __be32 c, all, old; 221 int i, ret = -EIO, retry = 5; 222 223 old = all = allocate ? cpu_to_be32(~0) : 0; 224 225 for (i = 0; i < 32; i++) { 226 if (!(channels_mask & 1 << i)) 227 continue; 228 229 ret = -EBUSY; 230 231 c = cpu_to_be32(1 << (31 - i)); 232 if ((old & c) != (all & c)) 233 continue; 234 235 data[0] = old; 236 data[1] = old ^ c; 237 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, 238 irm_id, generation, SCODE_100, 239 offset, data, 8)) { 240 case RCODE_GENERATION: 241 /* A generation change frees all channels. */ 242 return allocate ? -EAGAIN : i; 243 244 case RCODE_COMPLETE: 245 if (data[0] == old) 246 return i; 247 248 old = data[0]; 249 250 /* Is the IRM 1394a-2000 compliant? */ 251 if ((data[0] & c) == (data[1] & c)) 252 continue; 253 254 /* 1394-1995 IRM, fall through to retry. */ 255 default: 256 if (retry) { 257 retry--; 258 i--; 259 } else { 260 ret = -EIO; 261 } 262 } 263 } 264 265 return ret; 266 } 267 268 static void deallocate_channel(struct fw_card *card, int irm_id, 269 int generation, int channel, __be32 buffer[2]) 270 { 271 u32 mask; 272 u64 offset; 273 274 mask = channel < 32 ? 1 << channel : 1 << (channel - 32); 275 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI : 276 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO; 277 278 manage_channel(card, irm_id, generation, mask, offset, false, buffer); 279 } 280 281 /** 282 * fw_iso_resource_manage - Allocate or deallocate a channel and/or bandwidth 283 * 284 * In parameters: card, generation, channels_mask, bandwidth, allocate 285 * Out parameters: channel, bandwidth 286 * This function blocks (sleeps) during communication with the IRM. 287 * 288 * Allocates or deallocates at most one channel out of channels_mask. 289 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0. 290 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for 291 * channel 0 and LSB for channel 63.) 292 * Allocates or deallocates as many bandwidth allocation units as specified. 293 * 294 * Returns channel < 0 if no channel was allocated or deallocated. 295 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. 296 * 297 * If generation is stale, deallocations succeed but allocations fail with 298 * channel = -EAGAIN. 299 * 300 * If channel allocation fails, no bandwidth will be allocated either. 301 * If bandwidth allocation fails, no channel will be allocated either. 302 * But deallocations of channel and bandwidth are tried independently 303 * of each other's success. 304 */ 305 void fw_iso_resource_manage(struct fw_card *card, int generation, 306 u64 channels_mask, int *channel, int *bandwidth, 307 bool allocate, __be32 buffer[2]) 308 { 309 u32 channels_hi = channels_mask; /* channels 31...0 */ 310 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */ 311 int irm_id, ret, c = -EINVAL; 312 313 spin_lock_irq(&card->lock); 314 irm_id = card->irm_node->node_id; 315 spin_unlock_irq(&card->lock); 316 317 if (channels_hi) 318 c = manage_channel(card, irm_id, generation, channels_hi, 319 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, 320 allocate, buffer); 321 if (channels_lo && c < 0) { 322 c = manage_channel(card, irm_id, generation, channels_lo, 323 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, 324 allocate, buffer); 325 if (c >= 0) 326 c += 32; 327 } 328 *channel = c; 329 330 if (allocate && channels_mask != 0 && c < 0) 331 *bandwidth = 0; 332 333 if (*bandwidth == 0) 334 return; 335 336 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, 337 allocate, buffer); 338 if (ret < 0) 339 *bandwidth = 0; 340 341 if (allocate && ret < 0) { 342 if (c >= 0) 343 deallocate_channel(card, irm_id, generation, c, buffer); 344 *channel = ret; 345 } 346 } 347