diff options
| author | Lior Amsalem <alior@marvell.com> | 2014-08-27 15:52:55 +0200 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2014-09-23 16:47:01 +0200 |
| commit | 22843545b20007ae33bc3774043303e0b44e3d65 (patch) | |
| tree | 9137a6256f925f8fcce6cb7bec5aafd60208025a /drivers/dma/mv_xor.c | |
| parent | dma: mv_xor: Remove dead code (diff) | |
| download | linux-22843545b20007ae33bc3774043303e0b44e3d65.tar.xz linux-22843545b20007ae33bc3774043303e0b44e3d65.zip | |
dma: mv_xor: Add support for DMA_INTERRUPT
The driver is capable of supporting DMA_INTERRUPT by issuing a dummy 128-byte
transfer. This helps removing a poll in the async_tx stack, replacing it with
a completion interrupt.
Signed-off-by: Lior Amsalem <alior@marvell.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/mv_xor.c')
| -rw-r--r-- | drivers/dma/mv_xor.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c index 744a0077e5aa..769d35c3a82b 100644 --- a/drivers/dma/mv_xor.c +++ b/drivers/dma/mv_xor.c @@ -538,6 +538,24 @@ mv_xor_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags); } +static struct dma_async_tx_descriptor * +mv_xor_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags) +{ + struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan); + dma_addr_t src, dest; + size_t len; + + src = mv_chan->dummy_src_addr; + dest = mv_chan->dummy_dst_addr; + len = MV_XOR_MIN_BYTE_COUNT; + + /* + * We implement the DMA_INTERRUPT operation as a minimum sized + * XOR operation with a single dummy source address. + */ + return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags); +} + static void mv_xor_free_chan_resources(struct dma_chan *chan) { struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan); @@ -881,6 +899,10 @@ static int mv_xor_channel_remove(struct mv_xor_chan *mv_chan) dma_free_coherent(dev, MV_XOR_POOL_SIZE, mv_chan->dma_desc_pool_virt, mv_chan->dma_desc_pool); + dma_unmap_single(dev, mv_chan->dummy_src_addr, + MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE); + dma_unmap_single(dev, mv_chan->dummy_dst_addr, + MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE); list_for_each_entry_safe(chan, _chan, &mv_chan->dmadev.channels, device_node) { @@ -910,6 +932,16 @@ mv_xor_channel_add(struct mv_xor_device *xordev, dma_dev = &mv_chan->dmadev; + /* + * These source and destination dummy buffers are used to implement + * a DMA_INTERRUPT operation as a minimum-sized XOR operation. + * Hence, we only need to map the buffers at initialization-time. + */ + mv_chan->dummy_src_addr = dma_map_single(dma_dev->dev, + mv_chan->dummy_src, MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE); + mv_chan->dummy_dst_addr = dma_map_single(dma_dev->dev, + mv_chan->dummy_dst, MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE); + /* allocate coherent memory for hardware descriptors * note: writecombine gives slightly better performance, but * requires that we explicitly flush the writes @@ -934,6 +966,8 @@ mv_xor_channel_add(struct mv_xor_device *xordev, dma_dev->dev = &pdev->dev; /* set prep routines based on capability */ + if (dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask)) + dma_dev->device_prep_dma_interrupt = mv_xor_prep_dma_interrupt; if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) dma_dev->device_prep_dma_memcpy = mv_xor_prep_dma_memcpy; if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) { |