--- /dev/null
+/*
+ * 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(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);
Code Review / kvmfornfv.git / blobdiff