From 67d25f0d4e24775418aae403610cae99e27cdc3c Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Thu, 22 Oct 2015 11:41:00 +0200 Subject: [PATCH] dmaengine: hdmac: Add scatter-gathered memset support Just like memset support, the HDMAC might be used to do a memset over a discontiguous memory area. In such a case, we'll just build up a chain of memset descriptors over the contiguous chunks of memory to set, in order to allow such a support. Signed-off-by: Maxime Ripard Acked-by: Nicolas Ferre Signed-off-by: Vinod Koul --- drivers/dma/at_hdmac.c | 79 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index cad18f3660ae..4e55239c7a30 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -986,6 +986,83 @@ err_free_buffer: return NULL; } +static struct dma_async_tx_descriptor * +atc_prep_dma_memset_sg(struct dma_chan *chan, + struct scatterlist *sgl, + unsigned int sg_len, int value, + unsigned long flags) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma *atdma = to_at_dma(chan->device); + struct at_desc *desc = NULL, *first = NULL, *prev = NULL; + struct scatterlist *sg; + void __iomem *vaddr; + dma_addr_t paddr; + size_t total_len = 0; + int i; + + dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__, + value, sg_len, flags); + + if (unlikely(!sgl || !sg_len)) { + dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n", + __func__); + return NULL; + } + + vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr); + if (!vaddr) { + dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", + __func__); + return NULL; + } + *(u32*)vaddr = value; + + for_each_sg(sgl, sg, sg_len, i) { + dma_addr_t dest = sg_dma_address(sg); + size_t len = sg_dma_len(sg); + + dev_vdbg(chan2dev(chan), "%s: d0x%08x, l0x%zx\n", + __func__, dest, len); + + if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { + dev_err(chan2dev(chan), "%s: buffer is not aligned\n", + __func__); + goto err_put_desc; + } + + desc = atc_create_memset_desc(chan, paddr, dest, len); + if (!desc) + goto err_put_desc; + + atc_desc_chain(&first, &prev, desc); + + total_len += len; + } + + /* + * Only set the buffer pointers on the last descriptor to + * avoid free'ing while we have our transfer still going + */ + desc->memset_paddr = paddr; + desc->memset_vaddr = vaddr; + desc->memset_buffer = true; + + first->txd.cookie = -EBUSY; + first->total_len = total_len; + + /* set end-of-link on the descriptor */ + set_desc_eol(desc); + + first->txd.flags = flags; + + return &first->txd; + +err_put_desc: + atc_desc_put(atchan, first); + return NULL; +} + /** * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction * @chan: DMA channel @@ -1868,6 +1945,7 @@ static int __init at_dma_probe(struct platform_device *pdev) dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask); dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask); dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask); + dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask); dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask); dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask); dma_cap_set(DMA_SG, at91sam9g45_config.cap_mask); @@ -1989,6 +2067,7 @@ static int __init at_dma_probe(struct platform_device *pdev) if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) { atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset; + atdma->dma_common.device_prep_dma_memset_sg = atc_prep_dma_memset_sg; atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES; } -- 2.39.5