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/spinlock.h> 30 #include <linux/vmalloc.h> 31 32 #include <asm/byteorder.h> 33 34 #include "core.h" 35 36 /* 37 * Isochronous DMA context management 38 */ 39 40 int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, 41 int page_count, enum dma_data_direction direction) 42 { 43 int i, j; 44 dma_addr_t address; 45 46 buffer->page_count = page_count; 47 buffer->direction = direction; 48 49 buffer->pages = kmalloc(page_count * sizeof(buffer->pages[0]), 50 GFP_KERNEL); 51 if (buffer->pages == NULL) 52 goto out; 53 54 for (i = 0; i < buffer->page_count; i++) { 55 buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO); 56 if (buffer->pages[i] == NULL) 57 goto out_pages; 58 59 address = dma_map_page(card->device, buffer->pages[i], 60 0, PAGE_SIZE, direction); 61 if (dma_mapping_error(card->device, address)) { 62 __free_page(buffer->pages[i]); 63 goto out_pages; 64 } 65 set_page_private(buffer->pages[i], address); 66 } 67 68 return 0; 69 70 out_pages: 71 for (j = 0; j < i; j++) { 72 address = page_private(buffer->pages[j]); 73 dma_unmap_page(card->device, address, 74 PAGE_SIZE, direction); 75 __free_page(buffer->pages[j]); 76 } 77 kfree(buffer->pages); 78 out: 79 buffer->pages = NULL; 80 81 return -ENOMEM; 82 } 83 EXPORT_SYMBOL(fw_iso_buffer_init); 84 85 int fw_iso_buffer_map(struct fw_iso_buffer *buffer, struct vm_area_struct *vma) 86 { 87 unsigned long uaddr; 88 int i, err; 89 90 uaddr = vma->vm_start; 91 for (i = 0; i < buffer->page_count; i++) { 92 err = vm_insert_page(vma, uaddr, buffer->pages[i]); 93 if (err) 94 return err; 95 96 uaddr += PAGE_SIZE; 97 } 98 99 return 0; 100 } 101 102 void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, 103 struct fw_card *card) 104 { 105 int i; 106 dma_addr_t address; 107 108 for (i = 0; i < buffer->page_count; i++) { 109 address = page_private(buffer->pages[i]); 110 dma_unmap_page(card->device, address, 111 PAGE_SIZE, buffer->direction); 112 __free_page(buffer->pages[i]); 113 } 114 115 kfree(buffer->pages); 116 buffer->pages = NULL; 117 } 118 EXPORT_SYMBOL(fw_iso_buffer_destroy); 119 120 struct fw_iso_context *fw_iso_context_create(struct fw_card *card, 121 int type, int channel, int speed, size_t header_size, 122 fw_iso_callback_t callback, void *callback_data) 123 { 124 struct fw_iso_context *ctx; 125 126 ctx = card->driver->allocate_iso_context(card, 127 type, channel, header_size); 128 if (IS_ERR(ctx)) 129 return ctx; 130 131 ctx->card = card; 132 ctx->type = type; 133 ctx->channel = channel; 134 ctx->speed = speed; 135 ctx->header_size = header_size; 136 ctx->callback = callback; 137 ctx->callback_data = callback_data; 138 139 return ctx; 140 } 141 EXPORT_SYMBOL(fw_iso_context_create); 142 143 void fw_iso_context_destroy(struct fw_iso_context *ctx) 144 { 145 struct fw_card *card = ctx->card; 146 147 card->driver->free_iso_context(ctx); 148 } 149 EXPORT_SYMBOL(fw_iso_context_destroy); 150 151 int fw_iso_context_start(struct fw_iso_context *ctx, 152 int cycle, int sync, int tags) 153 { 154 return ctx->card->driver->start_iso(ctx, cycle, sync, tags); 155 } 156 EXPORT_SYMBOL(fw_iso_context_start); 157 158 int fw_iso_context_queue(struct fw_iso_context *ctx, 159 struct fw_iso_packet *packet, 160 struct fw_iso_buffer *buffer, 161 unsigned long payload) 162 { 163 struct fw_card *card = ctx->card; 164 165 return card->driver->queue_iso(ctx, packet, buffer, payload); 166 } 167 EXPORT_SYMBOL(fw_iso_context_queue); 168 169 int fw_iso_context_stop(struct fw_iso_context *ctx) 170 { 171 return ctx->card->driver->stop_iso(ctx); 172 } 173 EXPORT_SYMBOL(fw_iso_context_stop); 174 175 /* 176 * Isochronous bus resource management (channels, bandwidth), client side 177 */ 178 179 static int manage_bandwidth(struct fw_card *card, int irm_id, int generation, 180 int bandwidth, bool allocate, __be32 data[2]) 181 { 182 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0; 183 184 /* 185 * On a 1394a IRM with low contention, try < 1 is enough. 186 * On a 1394-1995 IRM, we need at least try < 2. 187 * Let's just do try < 5. 188 */ 189 for (try = 0; try < 5; try++) { 190 new = allocate ? old - bandwidth : old + bandwidth; 191 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL) 192 break; 193 194 data[0] = cpu_to_be32(old); 195 data[1] = cpu_to_be32(new); 196 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, 197 irm_id, generation, SCODE_100, 198 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE, 199 data, 8)) { 200 case RCODE_GENERATION: 201 /* A generation change frees all bandwidth. */ 202 return allocate ? -EAGAIN : bandwidth; 203 204 case RCODE_COMPLETE: 205 if (be32_to_cpup(data) == old) 206 return bandwidth; 207 208 old = be32_to_cpup(data); 209 /* Fall through. */ 210 } 211 } 212 213 return -EIO; 214 } 215 216 static int manage_channel(struct fw_card *card, int irm_id, int generation, 217 u32 channels_mask, u64 offset, bool allocate, __be32 data[2]) 218 { 219 __be32 c, all, old; 220 int i, retry = 5; 221 222 old = all = allocate ? cpu_to_be32(~0) : 0; 223 224 for (i = 0; i < 32; i++) { 225 if (!(channels_mask & 1 << i)) 226 continue; 227 228 c = cpu_to_be32(1 << (31 - i)); 229 if ((old & c) != (all & c)) 230 continue; 231 232 data[0] = old; 233 data[1] = old ^ c; 234 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, 235 irm_id, generation, SCODE_100, 236 offset, data, 8)) { 237 case RCODE_GENERATION: 238 /* A generation change frees all channels. */ 239 return allocate ? -EAGAIN : i; 240 241 case RCODE_COMPLETE: 242 if (data[0] == old) 243 return i; 244 245 old = data[0]; 246 247 /* Is the IRM 1394a-2000 compliant? */ 248 if ((data[0] & c) == (data[1] & c)) 249 continue; 250 251 /* 1394-1995 IRM, fall through to retry. */ 252 default: 253 if (retry--) 254 i--; 255 } 256 } 257 258 return -EIO; 259 } 260 261 static void deallocate_channel(struct fw_card *card, int irm_id, 262 int generation, int channel, __be32 buffer[2]) 263 { 264 u32 mask; 265 u64 offset; 266 267 mask = channel < 32 ? 1 << channel : 1 << (channel - 32); 268 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI : 269 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO; 270 271 manage_channel(card, irm_id, generation, mask, offset, false, buffer); 272 } 273 274 /** 275 * fw_iso_resource_manage - Allocate or deallocate a channel and/or bandwidth 276 * 277 * In parameters: card, generation, channels_mask, bandwidth, allocate 278 * Out parameters: channel, bandwidth 279 * This function blocks (sleeps) during communication with the IRM. 280 * 281 * Allocates or deallocates at most one channel out of channels_mask. 282 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0. 283 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for 284 * channel 0 and LSB for channel 63.) 285 * Allocates or deallocates as many bandwidth allocation units as specified. 286 * 287 * Returns channel < 0 if no channel was allocated or deallocated. 288 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. 289 * 290 * If generation is stale, deallocations succeed but allocations fail with 291 * channel = -EAGAIN. 292 * 293 * If channel allocation fails, no bandwidth will be allocated either. 294 * If bandwidth allocation fails, no channel will be allocated either. 295 * But deallocations of channel and bandwidth are tried independently 296 * of each other's success. 297 */ 298 void fw_iso_resource_manage(struct fw_card *card, int generation, 299 u64 channels_mask, int *channel, int *bandwidth, 300 bool allocate, __be32 buffer[2]) 301 { 302 u32 channels_hi = channels_mask; /* channels 31...0 */ 303 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */ 304 int irm_id, ret, c = -EINVAL; 305 306 spin_lock_irq(&card->lock); 307 irm_id = card->irm_node->node_id; 308 spin_unlock_irq(&card->lock); 309 310 if (channels_hi) 311 c = manage_channel(card, irm_id, generation, channels_hi, 312 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, 313 allocate, buffer); 314 if (channels_lo && c < 0) { 315 c = manage_channel(card, irm_id, generation, channels_lo, 316 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, 317 allocate, buffer); 318 if (c >= 0) 319 c += 32; 320 } 321 *channel = c; 322 323 if (allocate && channels_mask != 0 && c < 0) 324 *bandwidth = 0; 325 326 if (*bandwidth == 0) 327 return; 328 329 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, 330 allocate, buffer); 331 if (ret < 0) 332 *bandwidth = 0; 333 334 if (allocate && ret < 0 && c >= 0) { 335 deallocate_channel(card, irm_id, generation, c, buffer); 336 *channel = ret; 337 } 338 } 339