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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Isochronous I/O functionality:4 * - Isochronous DMA context management5 * - Isochronous bus resource management (channels, bandwidth), client side6 *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 management29 */30 31int 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 56int 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 79int 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}94EXPORT_SYMBOL(fw_iso_buffer_init);95 96void 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}115EXPORT_SYMBOL(fw_iso_buffer_destroy);116 117/* Convert DMA address to offset into virtually contiguous buffer. */118size_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 134struct 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}159EXPORT_SYMBOL(fw_iso_context_create);160 161void 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}169EXPORT_SYMBOL(fw_iso_context_destroy);170 171int 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}180EXPORT_SYMBOL(fw_iso_context_start);181 182int 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 189int 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}200EXPORT_SYMBOL(fw_iso_context_queue);201 202void 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}210EXPORT_SYMBOL(fw_iso_context_queue_flush);211 212/**213 * fw_iso_context_flush_completions() - process isochronous context in current process context.214 * @ctx: the isochronous context215 *216 * Process the isochronous context in the current process context. The registered callback function217 * is called when a queued packet buffer with the interrupt flag is completed, either after218 * transmission in the IT context or after being filled in the IR context. Additionally, the219 * callback function is also called for the packet buffer completed at last. Furthermore, the220 * callback function is called as well when the header buffer in the context becomes full. If it is221 * required to process the context asynchronously, fw_iso_context_schedule_flush_completions() is222 * available instead.223 *224 * Context: Process context. May sleep due to disable_work_sync().225 */226int fw_iso_context_flush_completions(struct fw_iso_context *ctx)227{228 int err;229 230 trace_isoc_outbound_flush_completions(ctx);231 trace_isoc_inbound_single_flush_completions(ctx);232 trace_isoc_inbound_multiple_flush_completions(ctx);233 234 might_sleep();235 236 // Avoid dead lock due to programming mistake.237 if (WARN_ON_ONCE(current_work() == &ctx->work))238 return 0;239 240 disable_work_sync(&ctx->work);241 242 err = ctx->card->driver->flush_iso_completions(ctx);243 244 enable_work(&ctx->work);245 246 return err;247}248EXPORT_SYMBOL(fw_iso_context_flush_completions);249 250int fw_iso_context_stop(struct fw_iso_context *ctx)251{252 int err;253 254 trace_isoc_outbound_stop(ctx);255 trace_isoc_inbound_single_stop(ctx);256 trace_isoc_inbound_multiple_stop(ctx);257 258 might_sleep();259 260 // Avoid dead lock due to programming mistake.261 if (WARN_ON_ONCE(current_work() == &ctx->work))262 return 0;263 264 err = ctx->card->driver->stop_iso(ctx);265 266 cancel_work_sync(&ctx->work);267 268 return err;269}270EXPORT_SYMBOL(fw_iso_context_stop);271 272/*273 * Isochronous bus resource management (channels, bandwidth), client side274 */275 276static int manage_bandwidth(struct fw_card *card, int irm_id, int generation,277 int bandwidth, bool allocate)278{279 int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0;280 __be32 data[2];281 282 /*283 * On a 1394a IRM with low contention, try < 1 is enough.284 * On a 1394-1995 IRM, we need at least try < 2.285 * Let's just do try < 5.286 */287 for (try = 0; try < 5; try++) {288 new = allocate ? old - bandwidth : old + bandwidth;289 if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL)290 return -EBUSY;291 292 data[0] = cpu_to_be32(old);293 data[1] = cpu_to_be32(new);294 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,295 irm_id, generation, SCODE_100,296 CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE,297 data, 8)) {298 case RCODE_GENERATION:299 /* A generation change frees all bandwidth. */300 return allocate ? -EAGAIN : bandwidth;301 302 case RCODE_COMPLETE:303 if (be32_to_cpup(data) == old)304 return bandwidth;305 306 old = be32_to_cpup(data);307 /* Fall through. */308 }309 }310 311 return -EIO;312}313 314static int manage_channel(struct fw_card *card, int irm_id, int generation,315 u32 channels_mask, u64 offset, bool allocate)316{317 __be32 bit, all, old;318 __be32 data[2];319 int channel, ret = -EIO, retry = 5;320 321 old = all = allocate ? cpu_to_be32(~0) : 0;322 323 for (channel = 0; channel < 32; channel++) {324 if (!(channels_mask & 1 << channel))325 continue;326 327 ret = -EBUSY;328 329 bit = cpu_to_be32(1 << (31 - channel));330 if ((old & bit) != (all & bit))331 continue;332 333 data[0] = old;334 data[1] = old ^ bit;335 switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP,336 irm_id, generation, SCODE_100,337 offset, data, 8)) {338 case RCODE_GENERATION:339 /* A generation change frees all channels. */340 return allocate ? -EAGAIN : channel;341 342 case RCODE_COMPLETE:343 if (data[0] == old)344 return channel;345 346 old = data[0];347 348 /* Is the IRM 1394a-2000 compliant? */349 if ((data[0] & bit) == (data[1] & bit))350 continue;351 352 fallthrough; /* It's a 1394-1995 IRM, retry */353 default:354 if (retry) {355 retry--;356 channel--;357 } else {358 ret = -EIO;359 }360 }361 }362 363 return ret;364}365 366static void deallocate_channel(struct fw_card *card, int irm_id,367 int generation, int channel)368{369 u32 mask;370 u64 offset;371 372 mask = channel < 32 ? 1 << channel : 1 << (channel - 32);373 offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI :374 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO;375 376 manage_channel(card, irm_id, generation, mask, offset, false);377}378 379/**380 * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth381 * @card: card interface for this action382 * @generation: bus generation383 * @channels_mask: bitmask for channel allocation384 * @channel: pointer for returning channel allocation result385 * @bandwidth: pointer for returning bandwidth allocation result386 * @allocate: whether to allocate (true) or deallocate (false)387 *388 * In parameters: card, generation, channels_mask, bandwidth, allocate389 * Out parameters: channel, bandwidth390 *391 * This function blocks (sleeps) during communication with the IRM.392 *393 * Allocates or deallocates at most one channel out of channels_mask.394 * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0.395 * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for396 * channel 0 and LSB for channel 63.)397 * Allocates or deallocates as many bandwidth allocation units as specified.398 *399 * Returns channel < 0 if no channel was allocated or deallocated.400 * Returns bandwidth = 0 if no bandwidth was allocated or deallocated.401 *402 * If generation is stale, deallocations succeed but allocations fail with403 * channel = -EAGAIN.404 *405 * If channel allocation fails, no bandwidth will be allocated either.406 * If bandwidth allocation fails, no channel will be allocated either.407 * But deallocations of channel and bandwidth are tried independently408 * of each other's success.409 */410void fw_iso_resource_manage(struct fw_card *card, int generation,411 u64 channels_mask, int *channel, int *bandwidth,412 bool allocate)413{414 u32 channels_hi = channels_mask; /* channels 31...0 */415 u32 channels_lo = channels_mask >> 32; /* channels 63...32 */416 int irm_id, ret, c = -EINVAL;417 418 scoped_guard(spinlock_irq, &card->lock)419 irm_id = card->irm_node->node_id;420 421 if (channels_hi)422 c = manage_channel(card, irm_id, generation, channels_hi,423 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI,424 allocate);425 if (channels_lo && c < 0) {426 c = manage_channel(card, irm_id, generation, channels_lo,427 CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO,428 allocate);429 if (c >= 0)430 c += 32;431 }432 *channel = c;433 434 if (allocate && channels_mask != 0 && c < 0)435 *bandwidth = 0;436 437 if (*bandwidth == 0)438 return;439 440 ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate);441 if (ret < 0)442 *bandwidth = 0;443 444 if (allocate && ret < 0) {445 if (c >= 0)446 deallocate_channel(card, irm_id, generation, c);447 *channel = ret;448 }449}450EXPORT_SYMBOL(fw_iso_resource_manage);451