diff options
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/sh/rcar-dmac.c | 78 |
1 files changed, 58 insertions, 20 deletions
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 6e7cdab61827..f71a3dc89048 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -64,6 +64,7 @@ struct rcar_dmac_hw_desc { * @chunks: list of transfer chunks for this transfer * @running: the transfer chunk being currently processed * @nchunks: number of transfer chunks for this transfer + * @hwdescs.use: whether the transfer descriptor uses hardware descriptors * @hwdescs.mem: hardware descriptors memory for the transfer * @hwdescs.dma: device address of the hardware descriptors memory * @hwdescs.size: size of the hardware descriptors in bytes @@ -82,6 +83,7 @@ struct rcar_dmac_desc { unsigned int nchunks; struct { + bool use; struct rcar_dmac_hw_desc *mem; dma_addr_t dma; size_t size; @@ -322,7 +324,7 @@ static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan) if (chan->mid_rid >= 0) rcar_dmac_chan_write(chan, RCAR_DMARS, chan->mid_rid); - if (desc->hwdescs.mem) { + if (desc->hwdescs.use) { dev_dbg(chan->chan.device->dev, "chan%u: queue desc %p: %u@%pad\n", chan->index, desc, desc->nchunks, &desc->hwdescs.dma); @@ -480,8 +482,8 @@ static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) * @desc: the descriptor * * Put the descriptor and its transfer chunk descriptors back in the channel's - * free descriptors lists, and free the hardware descriptors list memory. The - * descriptor's chunks list will be reinitialized to an empty list as a result. + * free descriptors lists. The descriptor's chunks list will be reinitialized to + * an empty list as a result. * * The descriptor must have been removed from the channel's lists before calling * this function. @@ -491,12 +493,6 @@ static int rcar_dmac_desc_alloc(struct rcar_dmac_chan *chan, gfp_t gfp) static void rcar_dmac_desc_put(struct rcar_dmac_chan *chan, struct rcar_dmac_desc *desc) { - if (desc->hwdescs.mem) { - dma_free_coherent(NULL, desc->hwdescs.size, desc->hwdescs.mem, - desc->hwdescs.dma); - desc->hwdescs.mem = NULL; - } - spin_lock_irq(&chan->lock); list_splice_tail_init(&desc->chunks, &chan->desc.chunks_free); list_add_tail(&desc->node, &chan->desc.free); @@ -651,20 +647,50 @@ rcar_dmac_xfer_chunk_get(struct rcar_dmac_chan *chan) return chunk; } -static void rcar_dmac_alloc_hwdesc(struct rcar_dmac_chan *chan, - struct rcar_dmac_desc *desc) +static void rcar_dmac_realloc_hwdesc(struct rcar_dmac_chan *chan, + struct rcar_dmac_desc *desc, size_t size) +{ + /* + * dma_alloc_coherent() allocates memory in page size increments. To + * avoid reallocating the hardware descriptors when the allocated size + * wouldn't change align the requested size to a multiple of the page + * size. + */ + size = PAGE_ALIGN(size); + + if (desc->hwdescs.size == size) + return; + + if (desc->hwdescs.mem) { + dma_free_coherent(NULL, desc->hwdescs.size, desc->hwdescs.mem, + desc->hwdescs.dma); + desc->hwdescs.mem = NULL; + desc->hwdescs.size = 0; + } + + if (!size) + return; + + desc->hwdescs.mem = dma_alloc_coherent(NULL, size, &desc->hwdescs.dma, + GFP_NOWAIT); + if (!desc->hwdescs.mem) + return; + + desc->hwdescs.size = size; +} + +static void rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan, + struct rcar_dmac_desc *desc) { struct rcar_dmac_xfer_chunk *chunk; struct rcar_dmac_hw_desc *hwdesc; - size_t size = desc->nchunks * sizeof(*hwdesc); - hwdesc = dma_alloc_coherent(NULL, size, &desc->hwdescs.dma, GFP_NOWAIT); + rcar_dmac_realloc_hwdesc(chan, desc, desc->nchunks * sizeof(*hwdesc)); + + hwdesc = desc->hwdescs.mem; if (!hwdesc) return; - desc->hwdescs.mem = hwdesc; - desc->hwdescs.size = size; - list_for_each_entry(chunk, &desc->chunks, node) { hwdesc->sar = chunk->src_addr; hwdesc->dar = chunk->dst_addr; @@ -890,8 +916,9 @@ rcar_dmac_chan_prep_sg(struct rcar_dmac_chan *chan, struct scatterlist *sgl, * performance improvement would be significant enough compared to the * additional complexity remains to be investigated. */ - if (!highmem && nchunks > 1) - rcar_dmac_alloc_hwdesc(chan, desc); + desc->hwdescs.use = !highmem && nchunks > 1; + if (desc->hwdescs.use) + rcar_dmac_fill_hwdesc(chan, desc); return &desc->async_tx; } @@ -930,6 +957,8 @@ static void rcar_dmac_free_chan_resources(struct dma_chan *chan) struct rcar_dmac_chan *rchan = to_rcar_dmac_chan(chan); struct rcar_dmac *dmac = to_rcar_dmac(chan->device); struct rcar_dmac_desc_page *page, *_page; + struct rcar_dmac_desc *desc; + LIST_HEAD(list); /* Protect against ISR */ spin_lock_irq(&rchan->lock); @@ -944,6 +973,15 @@ static void rcar_dmac_free_chan_resources(struct dma_chan *chan) rchan->mid_rid = -EINVAL; } + list_splice(&rchan->desc.free, &list); + list_splice(&rchan->desc.pending, &list); + list_splice(&rchan->desc.active, &list); + list_splice(&rchan->desc.done, &list); + list_splice(&rchan->desc.wait, &list); + + list_for_each_entry(desc, &list, node) + rcar_dmac_realloc_hwdesc(rchan, desc, 0); + list_for_each_entry_safe(page, _page, &rchan->desc.pages, node) { list_del(&page->node); free_page((unsigned long)page); @@ -1114,7 +1152,7 @@ static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan, * descriptor pointer field in the CHCRB register. In non-descriptor * mode just use the running descriptor pointer. */ - if (desc->hwdescs.mem) { + if (desc->hwdescs.use) { dptr = (rcar_dmac_chan_read(chan, RCAR_DMACHCRB) & RCAR_DMACHCRB_DPTR_MASK) >> RCAR_DMACHCRB_DPTR_SHIFT; WARN_ON(dptr >= desc->nchunks); @@ -1234,7 +1272,7 @@ static irqreturn_t rcar_dmac_isr_transfer_end(struct rcar_dmac_chan *chan) * descriptor mode. Only update the running chunk pointer in * non-descriptor mode. */ - if (!desc->hwdescs.mem) { + if (!desc->hwdescs.use) { /* * If we haven't completed the last transfer chunk simply move * to the next one. Only wake the IRQ thread if the transfer is |