From b2440442ccb68479fa6d307917419983f3c87e83 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Nuno=20S=C3=A1?= Date: Tue, 4 Nov 2025 16:22:27 +0000 Subject: [PATCH] dma: dma-axi-dmac: support bigger than 32bits addresses MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In some supported platforms as ARCH_ZYNQMP, part of the memory is mapped above 32bit addresses and since the DMA mask, by default, is set to 32bits, we would need to rely on swiotlb (which incurs a performance penalty) for the DMA mappings. Thus, we can write either the SRC or DEST high addresses with 1's and read them back. The last bit set on the return value will reflect the IP address bus width and so we can update the device DMA mask accordingly. While at it, support bigger that 32 bits transfers in IP without HW scatter gather support. Signed-off-by: Nuno Sá base-commit: 398035178503bf662281bbffb4bebce1460a4bc5 change-id: 20251104-axi-dmac-fixes-and-improvs-e3ad512a329c Acked-by: Michael Hennerich Link: https://patch.msgid.link/20251104-axi-dmac-fixes-and-improvs-v1-3-3e6fd9328f72@analog.com Signed-off-by: Vinod Koul --- drivers/dma/dma-axi-dmac.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c index 0f25f6d8ae71..15c569449a28 100644 --- a/drivers/dma/dma-axi-dmac.c +++ b/drivers/dma/dma-axi-dmac.c @@ -69,7 +69,9 @@ #define AXI_DMAC_REG_START_TRANSFER 0x408 #define AXI_DMAC_REG_FLAGS 0x40c #define AXI_DMAC_REG_DEST_ADDRESS 0x410 +#define AXI_DMAC_REG_DEST_ADDRESS_HIGH 0x490 #define AXI_DMAC_REG_SRC_ADDRESS 0x414 +#define AXI_DMAC_REG_SRC_ADDRESS_HIGH 0x494 #define AXI_DMAC_REG_X_LENGTH 0x418 #define AXI_DMAC_REG_Y_LENGTH 0x41c #define AXI_DMAC_REG_DEST_STRIDE 0x420 @@ -271,11 +273,14 @@ static void axi_dmac_start_transfer(struct axi_dmac_chan *chan) if (!chan->hw_sg) { if (axi_dmac_dest_is_mem(chan)) { axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS, sg->hw->dest_addr); + axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS_HIGH, + sg->hw->dest_addr >> 32); axi_dmac_write(dmac, AXI_DMAC_REG_DEST_STRIDE, sg->hw->dst_stride); } if (axi_dmac_src_is_mem(chan)) { axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS, sg->hw->src_addr); + axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS_HIGH, sg->hw->src_addr >> 32); axi_dmac_write(dmac, AXI_DMAC_REG_SRC_STRIDE, sg->hw->src_stride); } } @@ -990,6 +995,9 @@ static int axi_dmac_read_chan_config(struct device *dev, struct axi_dmac *dmac) static int axi_dmac_detect_caps(struct axi_dmac *dmac, unsigned int version) { struct axi_dmac_chan *chan = &dmac->chan; + struct device *dev = dmac->dma_dev.dev; + u32 mask; + int ret; axi_dmac_write(dmac, AXI_DMAC_REG_FLAGS, AXI_DMAC_FLAG_CYCLIC); if (axi_dmac_read(dmac, AXI_DMAC_REG_FLAGS) == AXI_DMAC_FLAG_CYCLIC) @@ -1024,6 +1032,22 @@ static int axi_dmac_detect_caps(struct axi_dmac *dmac, unsigned int version) return -ENODEV; } + if (axi_dmac_dest_is_mem(chan)) { + axi_dmac_write(dmac, AXI_DMAC_REG_DEST_ADDRESS_HIGH, 0xffffffff); + mask = axi_dmac_read(dmac, AXI_DMAC_REG_DEST_ADDRESS_HIGH); + } else { + axi_dmac_write(dmac, AXI_DMAC_REG_SRC_ADDRESS_HIGH, 0xffffffff); + mask = axi_dmac_read(dmac, AXI_DMAC_REG_SRC_ADDRESS_HIGH); + } + + mask = 32 + fls(mask); + + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(mask)); + if (ret) { + dev_err(dev, "DMA mask set error %d\n", ret); + return ret; + } + if (version >= ADI_AXI_PCORE_VER(4, 2, 'a')) chan->hw_partial_xfer = true; -- 2.47.3