typedef int (*descriptor_callback_t)(struct context *ctx,
struct descriptor *d,
struct descriptor *last);
+
+/*
+ * A buffer that contains a block of DMA-able coherent memory used for
+ * storing a portion of a DMA descriptor program.
+ */
+struct descriptor_buffer {
+ struct list_head list;
+ dma_addr_t buffer_bus;
+ size_t buffer_size;
+ size_t used;
+ struct descriptor buffer[0];
+};
+
struct context {
struct fw_ohci *ohci;
u32 regs;
+ int total_allocation;
- struct descriptor *buffer;
- dma_addr_t buffer_bus;
- size_t buffer_size;
- struct descriptor *head_descriptor;
- struct descriptor *tail_descriptor;
- struct descriptor *tail_descriptor_last;
- struct descriptor *prev_descriptor;
+ /*
+ * List of page-sized buffers for storing DMA descriptors.
+ * Head of list contains buffers in use and tail of list contains
+ * free buffers.
+ */
+ struct list_head buffer_list;
+
+ /*
+ * Pointer to a buffer inside buffer_list that contains the tail
+ * end of the current DMA program.
+ */
+ struct descriptor_buffer *buffer_tail;
+
+ /*
+ * The descriptor containing the branch address of the first
+ * descriptor that has not yet been filled by the device.
+ */
+ struct descriptor *last;
+
+ /*
+ * The last descriptor in the DMA program. It contains the branch
+ * address that must be updated upon appending a new descriptor.
+ */
+ struct descriptor *prev;
descriptor_callback_t callback;
#define SELF_ID_BUF_SIZE 0x800
#define OHCI_TCODE_PHY_PACKET 0x0e
#define OHCI_VERSION_1_1 0x010010
-#define ISO_BUFFER_SIZE (64 * 1024)
-#define AT_BUFFER_SIZE 4096
static char ohci_driver_name[] = KBUILD_MODNAME;
static void context_tasklet(unsigned long data)
{
struct context *ctx = (struct context *) data;
- struct fw_ohci *ohci = ctx->ohci;
struct descriptor *d, *last;
u32 address;
int z;
+ struct descriptor_buffer *desc;
- dma_sync_single_for_cpu(ohci->card.device, ctx->buffer_bus,
- ctx->buffer_size, DMA_TO_DEVICE);
-
- d = ctx->tail_descriptor;
- last = ctx->tail_descriptor_last;
-
+ desc = list_entry(ctx->buffer_list.next,
+ struct descriptor_buffer, list);
+ last = ctx->last;
while (last->branch_address != 0) {
+ struct descriptor_buffer *old_desc = desc;
address = le32_to_cpu(last->branch_address);
z = address & 0xf;
- d = ctx->buffer + (address - ctx->buffer_bus) / sizeof(*d);
+ address &= ~0xf;
+
+ /* If the branch address points to a buffer outside of the
+ * current buffer, advance to the next buffer. */
+ if (address < desc->buffer_bus ||
+ address >= desc->buffer_bus + desc->used)
+ desc = list_entry(desc->list.next,
+ struct descriptor_buffer, list);
+ d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
last = find_branch_descriptor(d, z);
if (!ctx->callback(ctx, d, last))
break;
- ctx->tail_descriptor = d;
- ctx->tail_descriptor_last = last;
+ if (old_desc != desc) {
+ /* If we've advanced to the next buffer, move the
+ * previous buffer to the free list. */
+ unsigned long flags;
+ old_desc->used = 0;
+ spin_lock_irqsave(&ctx->ohci->lock, flags);
+ list_move_tail(&old_desc->list, &ctx->buffer_list);
+ spin_unlock_irqrestore(&ctx->ohci->lock, flags);
+ }
+ ctx->last = last;
}
}
+/*
+ * Allocate a new buffer and add it to the list of free buffers for this
+ * context. Must be called with ohci->lock held.
+ */
+static int
+context_add_buffer(struct context *ctx)
+{
+ struct descriptor_buffer *desc;
+ dma_addr_t bus_addr;
+ int offset;
+
+ /*
+ * 16MB of descriptors should be far more than enough for any DMA
+ * program. This will catch run-away userspace or DoS attacks.
+ */
+ if (ctx->total_allocation >= 16*1024*1024)
+ return -ENOMEM;
+
+ desc = dma_alloc_coherent(ctx->ohci->card.device, PAGE_SIZE,
+ &bus_addr, GFP_ATOMIC);
+ if (!desc)
+ return -ENOMEM;
+
+ offset = (void *)&desc->buffer - (void *)desc;
+ desc->buffer_size = PAGE_SIZE - offset;
+ desc->buffer_bus = bus_addr + offset;
+ desc->used = 0;
+
+ list_add_tail(&desc->list, &ctx->buffer_list);
+ ctx->total_allocation += PAGE_SIZE;
+
+ return 0;
+}
+
static int
context_init(struct context *ctx, struct fw_ohci *ohci,
- size_t buffer_size, u32 regs,
- descriptor_callback_t callback)
+ u32 regs, descriptor_callback_t callback)
{
ctx->ohci = ohci;
ctx->regs = regs;
- ctx->buffer_size = buffer_size;
- ctx->buffer = kmalloc(buffer_size, GFP_KERNEL);
- if (ctx->buffer == NULL)
+ ctx->total_allocation = 0;
+
+ INIT_LIST_HEAD(&ctx->buffer_list);
+ if (context_add_buffer(ctx) < 0)
return -ENOMEM;
+ ctx->buffer_tail = list_entry(ctx->buffer_list.next,
+ struct descriptor_buffer, list);
+
tasklet_init(&ctx->tasklet, context_tasklet, (unsigned long)ctx);
ctx->callback = callback;
- ctx->buffer_bus =
- dma_map_single(ohci->card.device, ctx->buffer,
- buffer_size, DMA_TO_DEVICE);
- if (dma_mapping_error(ctx->buffer_bus)) {
- kfree(ctx->buffer);
- return -ENOMEM;
- }
-
- ctx->head_descriptor = ctx->buffer;
- ctx->prev_descriptor = ctx->buffer;
- ctx->tail_descriptor = ctx->buffer;
- ctx->tail_descriptor_last = ctx->buffer;
-
/*
* We put a dummy descriptor in the buffer that has a NULL
* branch address and looks like it's been sent. That way we
- * have a descriptor to append DMA programs to. Also, the
- * ring buffer invariant is that it always has at least one
- * element so that head == tail means buffer full.
+ * have a descriptor to append DMA programs to.
*/
-
- memset(ctx->head_descriptor, 0, sizeof(*ctx->head_descriptor));
- ctx->head_descriptor->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
- ctx->head_descriptor->transfer_status = cpu_to_le16(0x8011);
- ctx->head_descriptor++;
+ memset(ctx->buffer_tail->buffer, 0, sizeof(*ctx->buffer_tail->buffer));
+ ctx->buffer_tail->buffer->control = cpu_to_le16(DESCRIPTOR_OUTPUT_LAST);
+ ctx->buffer_tail->buffer->transfer_status = cpu_to_le16(0x8011);
+ ctx->buffer_tail->used += sizeof(*ctx->buffer_tail->buffer);
+ ctx->last = ctx->buffer_tail->buffer;
+ ctx->prev = ctx->buffer_tail->buffer;
return 0;
}
context_release(struct context *ctx)
{
struct fw_card *card = &ctx->ohci->card;
+ struct descriptor_buffer *desc, *tmp;
- dma_unmap_single(card->device, ctx->buffer_bus,
- ctx->buffer_size, DMA_TO_DEVICE);
- kfree(ctx->buffer);
+ list_for_each_entry_safe(desc, tmp, &ctx->buffer_list, list)
+ dma_free_coherent(card->device, PAGE_SIZE, desc,
+ desc->buffer_bus -
+ ((void *)&desc->buffer - (void *)desc));
}
+/* Must be called with ohci->lock held */
static struct descriptor *
context_get_descriptors(struct context *ctx, int z, dma_addr_t *d_bus)
{
- struct descriptor *d, *tail, *end;
-
- d = ctx->head_descriptor;
- tail = ctx->tail_descriptor;
- end = ctx->buffer + ctx->buffer_size / sizeof(*d);
-
- if (d + z <= tail) {
- goto has_space;
- } else if (d > tail && d + z <= end) {
- goto has_space;
- } else if (d > tail && ctx->buffer + z <= tail) {
- d = ctx->buffer;
- goto has_space;
- }
+ struct descriptor *d = NULL;
+ struct descriptor_buffer *desc = ctx->buffer_tail;
+
+ if (z * sizeof(*d) > desc->buffer_size)
+ return NULL;
+
+ if (z * sizeof(*d) > desc->buffer_size - desc->used) {
+ /* No room for the descriptor in this buffer, so advance to the
+ * next one. */
- return NULL;
+ if (desc->list.next == &ctx->buffer_list) {
+ /* If there is no free buffer next in the list,
+ * allocate one. */
+ if (context_add_buffer(ctx) < 0)
+ return NULL;
+ }
+ desc = list_entry(desc->list.next,
+ struct descriptor_buffer, list);
+ ctx->buffer_tail = desc;
+ }
- has_space:
+ d = desc->buffer + desc->used / sizeof(*d);
memset(d, 0, z * sizeof(*d));
- *d_bus = ctx->buffer_bus + (d - ctx->buffer) * sizeof(*d);
+ *d_bus = desc->buffer_bus + desc->used;
return d;
}
struct fw_ohci *ohci = ctx->ohci;
reg_write(ohci, COMMAND_PTR(ctx->regs),
- le32_to_cpu(ctx->tail_descriptor_last->branch_address));
+ le32_to_cpu(ctx->last->branch_address));
reg_write(ohci, CONTROL_CLEAR(ctx->regs), ~0);
reg_write(ohci, CONTROL_SET(ctx->regs), CONTEXT_RUN | extra);
flush_writes(ohci);
struct descriptor *d, int z, int extra)
{
dma_addr_t d_bus;
+ struct descriptor_buffer *desc = ctx->buffer_tail;
- d_bus = ctx->buffer_bus + (d - ctx->buffer) * sizeof(*d);
+ d_bus = desc->buffer_bus + (d - desc->buffer) * sizeof(*d);
- ctx->head_descriptor = d + z + extra;
- ctx->prev_descriptor->branch_address = cpu_to_le32(d_bus | z);
- ctx->prev_descriptor = find_branch_descriptor(d, z);
-
- dma_sync_single_for_device(ctx->ohci->card.device, ctx->buffer_bus,
- ctx->buffer_size, DMA_TO_DEVICE);
+ desc->used += (z + extra) * sizeof(*d);
+ ctx->prev->branch_address = cpu_to_le32(d_bus | z);
+ ctx->prev = find_branch_descriptor(d, z);
reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
flush_writes(ctx->ohci);
if (ctx->header == NULL)
goto out;
- retval = context_init(&ctx->context, ohci, ISO_BUFFER_SIZE,
- regs, callback);
+ retval = context_init(&ctx->context, ohci, regs, callback);
if (retval < 0)
goto out_with_header;
unsigned long payload)
{
struct iso_context *ctx = container_of(base, struct iso_context, base);
+ unsigned long flags;
+ int retval;
+ spin_lock_irqsave(&ctx->context.ohci->lock, flags);
if (base->type == FW_ISO_CONTEXT_TRANSMIT)
- return ohci_queue_iso_transmit(base, packet, buffer, payload);
+ retval = ohci_queue_iso_transmit(base, packet, buffer, payload);
else if (ctx->context.ohci->version >= OHCI_VERSION_1_1)
- return ohci_queue_iso_receive_dualbuffer(base, packet,
+ retval = ohci_queue_iso_receive_dualbuffer(base, packet,
buffer, payload);
else
- return ohci_queue_iso_receive_packet_per_buffer(base, packet,
+ retval = ohci_queue_iso_receive_packet_per_buffer(base, packet,
buffer,
payload);
+ spin_unlock_irqrestore(&ctx->context.ohci->lock, flags);
+
+ return retval;
}
static const struct fw_card_driver ohci_driver = {
ar_context_init(&ohci->ar_response_ctx, ohci,
OHCI1394_AsRspRcvContextControlSet);
- context_init(&ohci->at_request_ctx, ohci, AT_BUFFER_SIZE,
+ context_init(&ohci->at_request_ctx, ohci,
OHCI1394_AsReqTrContextControlSet, handle_at_packet);
- context_init(&ohci->at_response_ctx, ohci, AT_BUFFER_SIZE,
+ context_init(&ohci->at_response_ctx, ohci,
OHCI1394_AsRspTrContextControlSet, handle_at_packet);
reg_write(ohci, OHCI1394_IsoRecvIntMaskSet, ~0);
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