firewire: ohci: fix isochronous DMA synchronization

Add the dma_sync_single_* calls necessary to ensure proper cache
synchronization for isochronous data buffers on non-coherent
architectures.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index b6977149394e2076dec1528dbae0eb553911e3ad..6628feaa76229009f1bf5f62b3419d9e79dcea35 100644 (file)
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -126,6 +126,7 @@ struct context {
        struct fw_ohci *ohci;
        u32 regs;
        int total_allocation;
+       u32 current_bus;
        bool running;
        bool flushing;
 
@@ -1057,6 +1058,7 @@ static void context_tasklet(unsigned long data)
                address = le32_to_cpu(last->branch_address);
                z = address & 0xf;
                address &= ~0xf;
+               ctx->current_bus = address;
 
                /* If the branch address points to a buffer outside of the
                 * current buffer, advance to the next buffer. */
@@ -2697,6 +2699,7 @@ static int handle_ir_packet_per_buffer(struct context *context,
        struct iso_context *ctx =
                container_of(context, struct iso_context, context);
        struct descriptor *pd;
+       u32 buffer_dma;
        __le32 *ir_header;
        void *p;
 
@@ -2707,6 +2710,16 @@ static int handle_ir_packet_per_buffer(struct context *context,
                /* Descriptor(s) not done yet, stop iteration */
                return 0;
 
+       while (!(d->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))) {
+               d++;
+               buffer_dma = le32_to_cpu(d->data_address);
+               dma_sync_single_range_for_cpu(context->ohci->card.device,
+                                             buffer_dma & PAGE_MASK,
+                                             buffer_dma & ~PAGE_MASK,
+                                             le16_to_cpu(d->req_count),
+                                             DMA_FROM_DEVICE);
+       }
+
        p = last + 1;
        copy_iso_headers(ctx, p);
 
@@ -2729,11 +2742,19 @@ static int handle_ir_buffer_fill(struct context *context,
 {
        struct iso_context *ctx =
                container_of(context, struct iso_context, context);
+       u32 buffer_dma;
 
        if (!last->transfer_status)
                /* Descriptor(s) not done yet, stop iteration */
                return 0;
 
+       buffer_dma = le32_to_cpu(last->data_address);
+       dma_sync_single_range_for_cpu(context->ohci->card.device,
+                                     buffer_dma & PAGE_MASK,
+                                     buffer_dma & ~PAGE_MASK,
+                                     le16_to_cpu(last->req_count),
+                                     DMA_FROM_DEVICE);
+
        if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS)
                ctx->base.callback.mc(&ctx->base,
                                      le32_to_cpu(last->data_address) +
@@ -2744,6 +2765,43 @@ static int handle_ir_buffer_fill(struct context *context,
        return 1;
 }
 
+static inline void sync_it_packet_for_cpu(struct context *context,
+                                         struct descriptor *pd)
+{
+       __le16 control;
+       u32 buffer_dma;
+
+       /* only packets beginning with OUTPUT_MORE* have data buffers */
+       if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
+               return;
+
+       /* skip over the OUTPUT_MORE_IMMEDIATE descriptor */
+       pd += 2;
+
+       /*
+        * If the packet has a header, the first OUTPUT_MORE/LAST descriptor's
+        * data buffer is in the context program's coherent page and must not
+        * be synced.
+        */
+       if ((le32_to_cpu(pd->data_address) & PAGE_MASK) ==
+           (context->current_bus          & PAGE_MASK)) {
+               if (pd->control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS))
+                       return;
+               pd++;
+       }
+
+       do {
+               buffer_dma = le32_to_cpu(pd->data_address);
+               dma_sync_single_range_for_cpu(context->ohci->card.device,
+                                             buffer_dma & PAGE_MASK,
+                                             buffer_dma & ~PAGE_MASK,
+                                             le16_to_cpu(pd->req_count),
+                                             DMA_TO_DEVICE);
+               control = pd->control;
+               pd++;
+       } while (!(control & cpu_to_le16(DESCRIPTOR_BRANCH_ALWAYS)));
+}
+
 static int handle_it_packet(struct context *context,
                            struct descriptor *d,
                            struct descriptor *last)
@@ -2760,6 +2818,8 @@ static int handle_it_packet(struct context *context,
                /* Descriptor(s) not done yet, stop iteration */
                return 0;
 
+       sync_it_packet_for_cpu(context, d);
+
        i = ctx->header_length;
        if (i + 4 < PAGE_SIZE) {
                /* Present this value as big-endian to match the receive code */
@@ -3129,6 +3189,10 @@ static int queue_iso_transmit(struct iso_context *ctx,
                page_bus = page_private(buffer->pages[page]);
                pd[i].data_address = cpu_to_le32(page_bus + offset);
 
+               dma_sync_single_range_for_device(ctx->context.ohci->card.device,
+                                                page_bus, offset, length,
+                                                DMA_TO_DEVICE);
+
                payload_index += length;
        }
 
@@ -3153,6 +3217,7 @@ static int queue_iso_packet_per_buffer(struct iso_context *ctx,
                                       struct fw_iso_buffer *buffer,
                                       unsigned long payload)
 {
+       struct device *device = ctx->context.ohci->card.device;
        struct descriptor *d, *pd;
        dma_addr_t d_bus, page_bus;
        u32 z, header_z, rest;
@@ -3207,6 +3272,10 @@ static int queue_iso_packet_per_buffer(struct iso_context *ctx,
                        page_bus = page_private(buffer->pages[page]);
                        pd->data_address = cpu_to_le32(page_bus + offset);
 
+                       dma_sync_single_range_for_device(device, page_bus,
+                                                        offset, length,
+                                                        DMA_FROM_DEVICE);
+
                        offset = (offset + length) & ~PAGE_MASK;
                        rest -= length;
                        if (offset == 0)
@@ -3266,6 +3335,10 @@ static int queue_iso_buffer_fill(struct iso_context *ctx,
                page_bus = page_private(buffer->pages[page]);
                d->data_address = cpu_to_le32(page_bus + offset);
 
+               dma_sync_single_range_for_device(ctx->context.ohci->card.device,
+                                                page_bus, offset, length,
+                                                DMA_FROM_DEVICE);
+
                rest -= length;
                offset = 0;
                page++;