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