firewire: Generalize the iso transmit descriptor buffer logic.
The descriptor circular buffer logic used for iso transmission is
useful for async transmit too, so pull the sharable logic out in
a few standalone functions.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index 8499d70..86fe55c 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -75,6 +75,30 @@
struct tasklet_struct tasklet;
};
+struct context;
+
+typedef int (*descriptor_callback_t)(struct context *ctx,
+ struct descriptor *d,
+ struct descriptor *last);
+struct context {
+ struct fw_ohci *ohci;
+ u32 regs;
+
+ 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;
+
+ descriptor_callback_t callback;
+
+ struct tasklet_struct tasklet;
+};
+
+
+
struct at_context {
struct fw_ohci *ohci;
dma_addr_t descriptor_bus;
@@ -103,15 +127,7 @@
struct iso_context {
struct fw_iso_context base;
- struct tasklet_struct tasklet;
- u32 regs;
-
- struct descriptor *buffer;
- dma_addr_t buffer_bus;
- struct descriptor *head_descriptor;
- struct descriptor *tail_descriptor;
- struct descriptor *tail_descriptor_last;
- struct descriptor *prev_descriptor;
+ struct context context;
};
#define CONFIG_ROM_SIZE 1024
@@ -394,6 +410,154 @@
return 0;
}
+
+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;
+
+ 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;
+
+ while (last->branch_address != 0) {
+ address = le32_to_cpu(last->branch_address);
+ z = address & 0xf;
+ d = ctx->buffer + (address - ctx->buffer_bus) / sizeof *d;
+ last = (z == 2) ? d : d + z - 1;
+
+ if (!ctx->callback(ctx, d, last))
+ break;
+
+ ctx->tail_descriptor = d;
+ ctx->tail_descriptor_last = last;
+ }
+}
+
+static int
+context_init(struct context *ctx, struct fw_ohci *ohci,
+ size_t buffer_size, 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)
+ return -ENOMEM;
+
+ 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. */
+
+ 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++;
+
+ return 0;
+}
+
+ static void
+context_release(struct context *ctx)
+{
+ struct fw_card *card = &ctx->ohci->card;
+
+ dma_unmap_single(card->device, ctx->buffer_bus,
+ ctx->buffer_size, DMA_TO_DEVICE);
+ kfree(ctx->buffer);
+}
+
+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(struct descriptor);
+
+ 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;
+ }
+
+ return NULL;
+
+ has_space:
+ memset(d, 0, z * sizeof *d);
+ *d_bus = ctx->buffer_bus + (d - ctx->buffer) * sizeof *d;
+
+ return d;
+}
+
+static void context_run(struct context *ctx, u32 cycle_match)
+{
+ struct fw_ohci *ohci = ctx->ohci;
+
+ reg_write(ohci, command_ptr(ctx->regs),
+ le32_to_cpu(ctx->tail_descriptor_last->branch_address));
+ reg_write(ohci, control_clear(ctx->regs), ~0);
+ reg_write(ohci, control_set(ctx->regs), CONTEXT_RUN | cycle_match);
+ flush_writes(ohci);
+}
+
+static void context_append(struct context *ctx,
+ struct descriptor *d, int z, int extra)
+{
+ dma_addr_t d_bus;
+
+ d_bus = ctx->buffer_bus + (d - ctx->buffer) * sizeof *d;
+
+ ctx->head_descriptor = d + z + extra;
+ ctx->prev_descriptor->branch_address = cpu_to_le32(d_bus | z);
+ ctx->prev_descriptor = z == 2 ? d : d + z - 1;
+
+ dma_sync_single_for_device(ctx->ohci->card.device, ctx->buffer_bus,
+ ctx->buffer_size, DMA_TO_DEVICE);
+
+ reg_write(ctx->ohci, control_set(ctx->regs), CONTEXT_WAKE);
+ flush_writes(ctx->ohci);
+}
+
+static void context_stop(struct context *ctx)
+{
+ u32 reg;
+
+ reg_write(ctx->ohci, control_clear(ctx->regs), CONTEXT_RUN);
+
+ reg = reg_read(ctx->ohci, control_set(ctx->regs));
+ if (reg & CONTEXT_ACTIVE)
+ fw_notify("Tried to stop context, but it is still active "
+ "(0x%08x).\n", reg);
+}
static void
do_packet_callbacks(struct fw_ohci *ohci, struct list_head *list)
@@ -852,7 +1016,7 @@
while (iso_event) {
i = ffs(iso_event) - 1;
- tasklet_schedule(&ohci->ir_context_list[i].tasklet);
+ tasklet_schedule(&ohci->ir_context_list[i].context.tasklet);
iso_event &= ~(1 << i);
}
@@ -861,7 +1025,7 @@
while (iso_event) {
i = ffs(iso_event) - 1;
- tasklet_schedule(&ohci->it_context_list[i].tasklet);
+ tasklet_schedule(&ohci->it_context_list[i].context.tasklet);
iso_event &= ~(1 << i);
}
@@ -1085,64 +1249,41 @@
#define ISO_BUFFER_SIZE (64 * 1024)
-static void flush_iso_context(struct iso_context *ctx)
+static int handle_it_packet(struct context *context,
+ struct descriptor *d,
+ struct descriptor *last)
{
- struct fw_ohci *ohci = fw_ohci(ctx->base.card);
- struct descriptor *d, *last;
- u32 address;
- int z;
+ struct iso_context *ctx =
+ container_of(context, struct iso_context, context);
+
+ if (last->transfer_status == 0)
+ /* This descriptor isn't done yet, stop iteration. */
+ return 0;
- dma_sync_single_for_cpu(ohci->card.device, ctx->buffer_bus,
- ISO_BUFFER_SIZE, DMA_TO_DEVICE);
+ if (le16_to_cpu(last->control) & descriptor_irq_always)
+ ctx->base.callback(&ctx->base,
+ 0, le16_to_cpu(last->res_count),
+ ctx->base.callback_data);
- d = ctx->tail_descriptor;
- last = ctx->tail_descriptor_last;
-
- while (last->branch_address != 0 && last->transfer_status != 0) {
- address = le32_to_cpu(last->branch_address);
- z = address & 0xf;
- d = ctx->buffer + (address - ctx->buffer_bus) / sizeof *d;
-
- if (z == 2)
- last = d;
- else
- last = d + z - 1;
-
- if (le16_to_cpu(last->control) & descriptor_irq_always)
- ctx->base.callback(&ctx->base,
- 0, le16_to_cpu(last->res_count),
- ctx->base.callback_data);
- }
-
- ctx->tail_descriptor = d;
- ctx->tail_descriptor_last = last;
+ return 1;
}
-static void it_context_tasklet(unsigned long data)
-{
- struct iso_context *ctx = (struct iso_context *)data;
-
- flush_iso_context(ctx);
-}
-
-static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
- int type)
+static struct fw_iso_context *
+ohci_allocate_iso_context(struct fw_card *card, int type)
{
struct fw_ohci *ohci = fw_ohci(card);
struct iso_context *ctx, *list;
- void (*tasklet) (unsigned long data);
+ descriptor_callback_t callback;
u32 *mask;
unsigned long flags;
- int index;
+ int index, retval;
if (type == FW_ISO_CONTEXT_TRANSMIT) {
mask = &ohci->it_context_mask;
list = ohci->it_context_list;
- tasklet = it_context_tasklet;
+ callback = handle_it_packet;
} else {
- mask = &ohci->ir_context_mask;
- list = ohci->ir_context_list;
- tasklet = ir_context_tasklet;
+ return ERR_PTR(-EINVAL);
}
spin_lock_irqsave(&ohci->lock, flags);
@@ -1156,50 +1297,22 @@
ctx = &list[index];
memset(ctx, 0, sizeof *ctx);
- tasklet_init(&ctx->tasklet, tasklet, (unsigned long)ctx);
-
- ctx->buffer = kmalloc(ISO_BUFFER_SIZE, GFP_KERNEL);
- if (ctx->buffer == NULL)
- goto buffer_alloc_failed;
-
- ctx->buffer_bus =
- dma_map_single(card->device, ctx->buffer,
- ISO_BUFFER_SIZE, DMA_TO_DEVICE);
- if (dma_mapping_error(ctx->buffer_bus))
- goto buffer_map_failed;
-
- 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. */
-
- 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++;
+ retval = context_init(&ctx->context, ohci, ISO_BUFFER_SIZE,
+ OHCI1394_IsoXmitContextBase(index), callback);
+ if (retval < 0) {
+ spin_lock_irqsave(&ohci->lock, flags);
+ *mask |= 1 << index;
+ spin_unlock_irqrestore(&ohci->lock, flags);
+ return ERR_PTR(retval);
+ }
return &ctx->base;
-
- buffer_map_failed:
- kfree(ctx->buffer);
- buffer_alloc_failed:
- spin_lock_irqsave(&ohci->lock, flags);
- *mask |= 1 << index;
- spin_unlock_irqrestore(&ohci->lock, flags);
-
- return ERR_PTR(-ENOMEM);
}
static int ohci_send_iso(struct fw_iso_context *base, s32 cycle)
{
- struct iso_context *ctx = (struct iso_context *)base;
- struct fw_ohci *ohci = fw_ohci(ctx->base.card);
+ struct iso_context *ctx = container_of(base, struct iso_context, base);
+ struct fw_ohci *ohci = ctx->context.ohci;
u32 cycle_match = 0;
int index;
@@ -1209,12 +1322,7 @@
(cycle & 0x7fff) << 16;
reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
- reg_write(ohci, OHCI1394_IsoXmitCommandPtr(index),
- le32_to_cpu(ctx->tail_descriptor_last->branch_address));
- reg_write(ohci, OHCI1394_IsoXmitContextControlClear(index), ~0);
- reg_write(ohci, OHCI1394_IsoXmitContextControlSet(index),
- CONTEXT_RUN | cycle_match);
- flush_writes(ohci);
+ context_run(&ctx->context, cycle_match);
return 0;
}
@@ -1222,12 +1330,10 @@
static void ohci_free_iso_context(struct fw_iso_context *base)
{
struct fw_ohci *ohci = fw_ohci(base->card);
- struct iso_context *ctx = (struct iso_context *)base;
+ struct iso_context *ctx = container_of(base, struct iso_context, base);
unsigned long flags;
int index;
- flush_iso_context(ctx);
-
spin_lock_irqsave(&ohci->lock, flags);
if (ctx->base.type == FW_ISO_CONTEXT_TRANSMIT) {
@@ -1243,8 +1349,7 @@
}
flush_writes(ohci);
- dma_unmap_single(ohci->card.device, ctx->buffer_bus,
- ISO_BUFFER_SIZE, DMA_TO_DEVICE);
+ context_release(&ctx->context);
spin_unlock_irqrestore(&ohci->lock, flags);
}
@@ -1255,24 +1360,20 @@
struct fw_iso_buffer *buffer,
unsigned long payload)
{
- struct iso_context *ctx = (struct iso_context *)base;
- struct fw_ohci *ohci = fw_ohci(ctx->base.card);
- struct descriptor *d, *end, *last, *tail, *pd;
+ struct iso_context *ctx = container_of(base, struct iso_context, base);
+ struct descriptor *d, *last, *pd;
struct fw_iso_packet *p;
__le32 *header;
dma_addr_t d_bus, page_bus;
u32 z, header_z, payload_z, irq;
u32 payload_index, payload_end_index, next_page_index;
- int index, page, end_page, i, length, offset;
+ int page, end_page, i, length, offset;
/* FIXME: Cycle lost behavior should be configurable: lose
* packet, retransmit or terminate.. */
p = packet;
payload_index = payload;
- d = ctx->head_descriptor;
- tail = ctx->tail_descriptor;
- end = ctx->buffer + ISO_BUFFER_SIZE / sizeof(struct descriptor);
if (p->skip)
z = 1;
@@ -1293,21 +1394,9 @@
/* Get header size in number of descriptors. */
header_z = DIV_ROUND_UP(p->header_length, sizeof *d);
- if (d + z + header_z <= tail) {
- goto has_space;
- } else if (d > tail && d + z + header_z <= end) {
- goto has_space;
- } else if (d > tail && ctx->buffer + z + header_z <= tail) {
- d = ctx->buffer;
- goto has_space;
- }
-
- /* No space in buffer */
- return -1;
-
- has_space:
- memset(d, 0, (z + header_z) * sizeof *d);
- d_bus = ctx->buffer_bus + (d - ctx->buffer) * sizeof *d;
+ d = context_get_descriptors(&ctx->context, z + header_z, &d_bus);
+ if (d == NULL)
+ return -ENOMEM;
if (!p->skip) {
d[0].control = cpu_to_le16(descriptor_key_immediate);
@@ -1346,31 +1435,18 @@
payload_index += length;
}
- if (z == 2)
- last = d;
- else
- last = d + z - 1;
-
if (p->interrupt)
irq = descriptor_irq_always;
else
irq = descriptor_no_irq;
+ last = z == 2 ? d : d + z - 1;
last->control |= cpu_to_le16(descriptor_output_last |
descriptor_status |
descriptor_branch_always |
irq);
- dma_sync_single_for_device(ohci->card.device, ctx->buffer_bus,
- ISO_BUFFER_SIZE, DMA_TO_DEVICE);
-
- ctx->head_descriptor = d + z + header_z;
- ctx->prev_descriptor->branch_address = cpu_to_le32(d_bus | z);
- ctx->prev_descriptor = last;
-
- index = ctx - ohci->it_context_list;
- reg_write(ohci, OHCI1394_IsoXmitContextControlSet(index), CONTEXT_WAKE);
- flush_writes(ohci);
+ context_append(&ctx->context, d, z, header_z);
return 0;
}