| /* |
| * Isochronous I/O functionality: |
| * - Isochronous DMA context management |
| * - Isochronous bus resource management (channels, bandwidth), client side |
| * |
| * Copyright (C) 2006 Kristian Hoegsberg <krh@bitplanet.net> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software Foundation, |
| * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| #include <linux/dma-mapping.h> |
| #include <linux/errno.h> |
| #include <linux/firewire.h> |
| #include <linux/firewire-constants.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/vmalloc.h> |
| #include <linux/export.h> |
| |
| #include <asm/byteorder.h> |
| |
| #include "core.h" |
| |
| /* |
| * Isochronous DMA context management |
| */ |
| |
| int fw_iso_buffer_alloc(struct fw_iso_buffer *buffer, int page_count) |
| { |
| int i; |
| |
| buffer->page_count = 0; |
| buffer->page_count_mapped = 0; |
| buffer->pages = kmalloc_array(page_count, sizeof(buffer->pages[0]), |
| GFP_KERNEL); |
| if (buffer->pages == NULL) |
| return -ENOMEM; |
| |
| for (i = 0; i < page_count; i++) { |
| buffer->pages[i] = alloc_page(GFP_KERNEL | GFP_DMA32 | __GFP_ZERO); |
| if (buffer->pages[i] == NULL) |
| break; |
| } |
| buffer->page_count = i; |
| if (i < page_count) { |
| fw_iso_buffer_destroy(buffer, NULL); |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| int fw_iso_buffer_map_dma(struct fw_iso_buffer *buffer, struct fw_card *card, |
| enum dma_data_direction direction) |
| { |
| dma_addr_t address; |
| int i; |
| |
| buffer->direction = direction; |
| |
| for (i = 0; i < buffer->page_count; i++) { |
| address = dma_map_page(card->device, buffer->pages[i], |
| 0, PAGE_SIZE, direction); |
| if (dma_mapping_error(card->device, address)) |
| break; |
| |
| set_page_private(buffer->pages[i], address); |
| } |
| buffer->page_count_mapped = i; |
| if (i < buffer->page_count) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| int fw_iso_buffer_init(struct fw_iso_buffer *buffer, struct fw_card *card, |
| int page_count, enum dma_data_direction direction) |
| { |
| int ret; |
| |
| ret = fw_iso_buffer_alloc(buffer, page_count); |
| if (ret < 0) |
| return ret; |
| |
| ret = fw_iso_buffer_map_dma(buffer, card, direction); |
| if (ret < 0) |
| fw_iso_buffer_destroy(buffer, card); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(fw_iso_buffer_init); |
| |
| int fw_iso_buffer_map_vma(struct fw_iso_buffer *buffer, |
| struct vm_area_struct *vma) |
| { |
| unsigned long uaddr; |
| int i, err; |
| |
| uaddr = vma->vm_start; |
| for (i = 0; i < buffer->page_count; i++) { |
| err = vm_insert_page(vma, uaddr, buffer->pages[i]); |
| if (err) |
| return err; |
| |
| uaddr += PAGE_SIZE; |
| } |
| |
| return 0; |
| } |
| |
| void fw_iso_buffer_destroy(struct fw_iso_buffer *buffer, |
| struct fw_card *card) |
| { |
| int i; |
| dma_addr_t address; |
| |
| for (i = 0; i < buffer->page_count_mapped; i++) { |
| address = page_private(buffer->pages[i]); |
| dma_unmap_page(card->device, address, |
| PAGE_SIZE, buffer->direction); |
| } |
| for (i = 0; i < buffer->page_count; i++) |
| __free_page(buffer->pages[i]); |
| |
| kfree(buffer->pages); |
| buffer->pages = NULL; |
| buffer->page_count = 0; |
| buffer->page_count_mapped = 0; |
| } |
| EXPORT_SYMBOL(fw_iso_buffer_destroy); |
| |
| /* Convert DMA address to offset into virtually contiguous buffer. */ |
| size_t fw_iso_buffer_lookup(struct fw_iso_buffer *buffer, dma_addr_t completed) |
| { |
| size_t i; |
| dma_addr_t address; |
| ssize_t offset; |
| |
| for (i = 0; i < buffer->page_count; i++) { |
| address = page_private(buffer->pages[i]); |
| offset = (ssize_t)completed - (ssize_t)address; |
| if (offset > 0 && offset <= PAGE_SIZE) |
| return (i << PAGE_SHIFT) + offset; |
| } |
| |
| return 0; |
| } |
| |
| struct fw_iso_context *fw_iso_context_create(struct fw_card *card, |
| int type, int channel, int speed, size_t header_size, |
| fw_iso_callback_t callback, void *callback_data) |
| { |
| struct fw_iso_context *ctx; |
| |
| ctx = card->driver->allocate_iso_context(card, |
| type, channel, header_size); |
| if (IS_ERR(ctx)) |
| return ctx; |
| |
| ctx->card = card; |
| ctx->type = type; |
| ctx->channel = channel; |
| ctx->speed = speed; |
| ctx->header_size = header_size; |
| ctx->callback.sc = callback; |
| ctx->callback_data = callback_data; |
| |
| return ctx; |
| } |
| EXPORT_SYMBOL(fw_iso_context_create); |
| |
| void fw_iso_context_destroy(struct fw_iso_context *ctx) |
| { |
| ctx->card->driver->free_iso_context(ctx); |
| } |
| EXPORT_SYMBOL(fw_iso_context_destroy); |
| |
| int fw_iso_context_start(struct fw_iso_context *ctx, |
| int cycle, int sync, int tags) |
| { |
| return ctx->card->driver->start_iso(ctx, cycle, sync, tags); |
| } |
| EXPORT_SYMBOL(fw_iso_context_start); |
| |
| int fw_iso_context_set_channels(struct fw_iso_context *ctx, u64 *channels) |
| { |
| return ctx->card->driver->set_iso_channels(ctx, channels); |
| } |
| |
| int fw_iso_context_queue(struct fw_iso_context *ctx, |
| struct fw_iso_packet *packet, |
| struct fw_iso_buffer *buffer, |
| unsigned long payload) |
| { |
| return ctx->card->driver->queue_iso(ctx, packet, buffer, payload); |
| } |
| EXPORT_SYMBOL(fw_iso_context_queue); |
| |
| void fw_iso_context_queue_flush(struct fw_iso_context *ctx) |
| { |
| ctx->card->driver->flush_queue_iso(ctx); |
| } |
| EXPORT_SYMBOL(fw_iso_context_queue_flush); |
| |
| int fw_iso_context_flush_completions(struct fw_iso_context *ctx) |
| { |
| return ctx->card->driver->flush_iso_completions(ctx); |
| } |
| EXPORT_SYMBOL(fw_iso_context_flush_completions); |
| |
| int fw_iso_context_stop(struct fw_iso_context *ctx) |
| { |
| return ctx->card->driver->stop_iso(ctx); |
| } |
| EXPORT_SYMBOL(fw_iso_context_stop); |
| |
| /* |
| * Isochronous bus resource management (channels, bandwidth), client side |
| */ |
| |
| static int manage_bandwidth(struct fw_card *card, int irm_id, int generation, |
| int bandwidth, bool allocate) |
| { |
| int try, new, old = allocate ? BANDWIDTH_AVAILABLE_INITIAL : 0; |
| __be32 data[2]; |
| |
| /* |
| * On a 1394a IRM with low contention, try < 1 is enough. |
| * On a 1394-1995 IRM, we need at least try < 2. |
| * Let's just do try < 5. |
| */ |
| for (try = 0; try < 5; try++) { |
| new = allocate ? old - bandwidth : old + bandwidth; |
| if (new < 0 || new > BANDWIDTH_AVAILABLE_INITIAL) |
| return -EBUSY; |
| |
| data[0] = cpu_to_be32(old); |
| data[1] = cpu_to_be32(new); |
| switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, |
| irm_id, generation, SCODE_100, |
| CSR_REGISTER_BASE + CSR_BANDWIDTH_AVAILABLE, |
| data, 8)) { |
| case RCODE_GENERATION: |
| /* A generation change frees all bandwidth. */ |
| return allocate ? -EAGAIN : bandwidth; |
| |
| case RCODE_COMPLETE: |
| if (be32_to_cpup(data) == old) |
| return bandwidth; |
| |
| old = be32_to_cpup(data); |
| /* Fall through. */ |
| } |
| } |
| |
| return -EIO; |
| } |
| |
| static int manage_channel(struct fw_card *card, int irm_id, int generation, |
| u32 channels_mask, u64 offset, bool allocate) |
| { |
| __be32 bit, all, old; |
| __be32 data[2]; |
| int channel, ret = -EIO, retry = 5; |
| |
| old = all = allocate ? cpu_to_be32(~0) : 0; |
| |
| for (channel = 0; channel < 32; channel++) { |
| if (!(channels_mask & 1 << channel)) |
| continue; |
| |
| ret = -EBUSY; |
| |
| bit = cpu_to_be32(1 << (31 - channel)); |
| if ((old & bit) != (all & bit)) |
| continue; |
| |
| data[0] = old; |
| data[1] = old ^ bit; |
| switch (fw_run_transaction(card, TCODE_LOCK_COMPARE_SWAP, |
| irm_id, generation, SCODE_100, |
| offset, data, 8)) { |
| case RCODE_GENERATION: |
| /* A generation change frees all channels. */ |
| return allocate ? -EAGAIN : channel; |
| |
| case RCODE_COMPLETE: |
| if (data[0] == old) |
| return channel; |
| |
| old = data[0]; |
| |
| /* Is the IRM 1394a-2000 compliant? */ |
| if ((data[0] & bit) == (data[1] & bit)) |
| continue; |
| |
| /* 1394-1995 IRM, fall through to retry. */ |
| default: |
| if (retry) { |
| retry--; |
| channel--; |
| } else { |
| ret = -EIO; |
| } |
| } |
| } |
| |
| return ret; |
| } |
| |
| static void deallocate_channel(struct fw_card *card, int irm_id, |
| int generation, int channel) |
| { |
| u32 mask; |
| u64 offset; |
| |
| mask = channel < 32 ? 1 << channel : 1 << (channel - 32); |
| offset = channel < 32 ? CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI : |
| CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO; |
| |
| manage_channel(card, irm_id, generation, mask, offset, false); |
| } |
| |
| /** |
| * fw_iso_resource_manage() - Allocate or deallocate a channel and/or bandwidth |
| * |
| * In parameters: card, generation, channels_mask, bandwidth, allocate |
| * Out parameters: channel, bandwidth |
| * This function blocks (sleeps) during communication with the IRM. |
| * |
| * Allocates or deallocates at most one channel out of channels_mask. |
| * channels_mask is a bitfield with MSB for channel 63 and LSB for channel 0. |
| * (Note, the IRM's CHANNELS_AVAILABLE is a big-endian bitfield with MSB for |
| * channel 0 and LSB for channel 63.) |
| * Allocates or deallocates as many bandwidth allocation units as specified. |
| * |
| * Returns channel < 0 if no channel was allocated or deallocated. |
| * Returns bandwidth = 0 if no bandwidth was allocated or deallocated. |
| * |
| * If generation is stale, deallocations succeed but allocations fail with |
| * channel = -EAGAIN. |
| * |
| * If channel allocation fails, no bandwidth will be allocated either. |
| * If bandwidth allocation fails, no channel will be allocated either. |
| * But deallocations of channel and bandwidth are tried independently |
| * of each other's success. |
| */ |
| void fw_iso_resource_manage(struct fw_card *card, int generation, |
| u64 channels_mask, int *channel, int *bandwidth, |
| bool allocate) |
| { |
| u32 channels_hi = channels_mask; /* channels 31...0 */ |
| u32 channels_lo = channels_mask >> 32; /* channels 63...32 */ |
| int irm_id, ret, c = -EINVAL; |
| |
| spin_lock_irq(&card->lock); |
| irm_id = card->irm_node->node_id; |
| spin_unlock_irq(&card->lock); |
| |
| if (channels_hi) |
| c = manage_channel(card, irm_id, generation, channels_hi, |
| CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_HI, |
| allocate); |
| if (channels_lo && c < 0) { |
| c = manage_channel(card, irm_id, generation, channels_lo, |
| CSR_REGISTER_BASE + CSR_CHANNELS_AVAILABLE_LO, |
| allocate); |
| if (c >= 0) |
| c += 32; |
| } |
| *channel = c; |
| |
| if (allocate && channels_mask != 0 && c < 0) |
| *bandwidth = 0; |
| |
| if (*bandwidth == 0) |
| return; |
| |
| ret = manage_bandwidth(card, irm_id, generation, *bandwidth, allocate); |
| if (ret < 0) |
| *bandwidth = 0; |
| |
| if (allocate && ret < 0) { |
| if (c >= 0) |
| deallocate_channel(card, irm_id, generation, c); |
| *channel = ret; |
| } |
| } |
| EXPORT_SYMBOL(fw_iso_resource_manage); |