From a1daaa991ed1f13b86f6d9df174f21c4e23d33ba Mon Sep 17 00:00:00 2001 From: Ikjoon Jang Date: Tue, 6 Oct 2020 15:54:03 +0800 Subject: [PATCH] spi: spi-mtk-nor: use dma_alloc_coherent() for bounce buffer Use dma_alloc_coherent() for bounce buffer instead of kmalloc() to make sure the bounce buffer to be allocated within its DMAable range. Signed-off-by: Ikjoon Jang Link: https://lore.kernel.org/r/20201006155010.v5.2.I06cb65401ab5ad63ea30c4788d26633928d80f38@changeid Signed-off-by: Mark Brown --- drivers/spi/spi-mtk-nor.c | 94 ++++++++++++++++++++++++++--------------------- 1 file changed, 52 insertions(+), 42 deletions(-) diff --git a/drivers/spi/spi-mtk-nor.c b/drivers/spi/spi-mtk-nor.c index ea39736..c11bed2 100644 --- a/drivers/spi/spi-mtk-nor.c +++ b/drivers/spi/spi-mtk-nor.c @@ -97,6 +97,7 @@ struct mtk_nor { struct device *dev; void __iomem *base; u8 *buffer; + dma_addr_t buffer_dma; struct clk *spi_clk; struct clk *ctlr_clk; unsigned int spi_freq; @@ -145,6 +146,11 @@ static void mtk_nor_set_addr(struct mtk_nor *sp, const struct spi_mem_op *op) } } +static bool need_bounce(struct mtk_nor *sp, const struct spi_mem_op *op) +{ + return ((uintptr_t)op->data.buf.in & MTK_NOR_DMA_ALIGN_MASK); +} + static bool mtk_nor_match_read(const struct spi_mem_op *op) { int dummy = 0; @@ -238,6 +244,8 @@ static void mtk_nor_adj_prg_size(struct spi_mem_op *op) static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) { + struct mtk_nor *sp = spi_controller_get_devdata(mem->spi->master); + if (!op->data.nbytes) return 0; @@ -251,8 +259,7 @@ static int mtk_nor_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) if ((op->addr.val & MTK_NOR_DMA_ALIGN_MASK) || (op->data.nbytes < MTK_NOR_DMA_ALIGN)) op->data.nbytes = 1; - else if (!((ulong)(op->data.buf.in) & - MTK_NOR_DMA_ALIGN_MASK)) + else if (!need_bounce(sp, op)) op->data.nbytes &= ~MTK_NOR_DMA_ALIGN_MASK; else if (op->data.nbytes > MTK_NOR_BOUNCE_BUF_SIZE) op->data.nbytes = MTK_NOR_BOUNCE_BUF_SIZE; @@ -325,19 +332,12 @@ static void mtk_nor_setup_bus(struct mtk_nor *sp, const struct spi_mem_op *op) mtk_nor_rmw(sp, MTK_NOR_REG_BUSCFG, reg, MTK_NOR_BUS_MODE_MASK); } -static int mtk_nor_read_dma(struct mtk_nor *sp, u32 from, unsigned int length, - u8 *buffer) +static int mtk_nor_dma_exec(struct mtk_nor *sp, u32 from, unsigned int length, + dma_addr_t dma_addr) { int ret = 0; ulong delay; u32 reg; - dma_addr_t dma_addr; - - dma_addr = dma_map_single(sp->dev, buffer, length, DMA_FROM_DEVICE); - if (dma_mapping_error(sp->dev, dma_addr)) { - dev_err(sp->dev, "failed to map dma buffer.\n"); - return -EINVAL; - } writel(from, sp->base + MTK_NOR_REG_DMA_FADR); writel(dma_addr, sp->base + MTK_NOR_REG_DMA_DADR); @@ -362,30 +362,49 @@ static int mtk_nor_read_dma(struct mtk_nor *sp, u32 from, unsigned int length, (delay + 1) * 100); } - dma_unmap_single(sp->dev, dma_addr, length, DMA_FROM_DEVICE); if (ret < 0) dev_err(sp->dev, "dma read timeout.\n"); return ret; } -static int mtk_nor_read_bounce(struct mtk_nor *sp, u32 from, - unsigned int length, u8 *buffer) +static int mtk_nor_read_bounce(struct mtk_nor *sp, const struct spi_mem_op *op) { unsigned int rdlen; int ret; - if (length & MTK_NOR_DMA_ALIGN_MASK) - rdlen = (length + MTK_NOR_DMA_ALIGN) & ~MTK_NOR_DMA_ALIGN_MASK; + if (op->data.nbytes & MTK_NOR_DMA_ALIGN_MASK) + rdlen = (op->data.nbytes + MTK_NOR_DMA_ALIGN) & ~MTK_NOR_DMA_ALIGN_MASK; else - rdlen = length; + rdlen = op->data.nbytes; - ret = mtk_nor_read_dma(sp, from, rdlen, sp->buffer); - if (ret) - return ret; + ret = mtk_nor_dma_exec(sp, op->addr.val, rdlen, sp->buffer_dma); - memcpy(buffer, sp->buffer, length); - return 0; + if (!ret) + memcpy(op->data.buf.in, sp->buffer, op->data.nbytes); + + return ret; +} + +static int mtk_nor_read_dma(struct mtk_nor *sp, const struct spi_mem_op *op) +{ + int ret; + dma_addr_t dma_addr; + + if (need_bounce(sp, op)) + return mtk_nor_read_bounce(sp, op); + + dma_addr = dma_map_single(sp->dev, op->data.buf.in, + op->data.nbytes, DMA_FROM_DEVICE); + + if (dma_mapping_error(sp->dev, dma_addr)) + return -EINVAL; + + ret = mtk_nor_dma_exec(sp, op->addr.val, op->data.nbytes, dma_addr); + + dma_unmap_single(sp->dev, dma_addr, op->data.nbytes, DMA_FROM_DEVICE); + + return ret; } static int mtk_nor_read_pio(struct mtk_nor *sp, const struct spi_mem_op *op) @@ -566,15 +585,8 @@ static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) if (op->data.nbytes == 1) { mtk_nor_set_addr(sp, op); return mtk_nor_read_pio(sp, op); - } else if (((ulong)(op->data.buf.in) & - MTK_NOR_DMA_ALIGN_MASK)) { - return mtk_nor_read_bounce(sp, op->addr.val, - op->data.nbytes, - op->data.buf.in); } else { - return mtk_nor_read_dma(sp, op->addr.val, - op->data.nbytes, - op->data.buf.in); + return mtk_nor_read_dma(sp, op); } } @@ -729,7 +741,6 @@ static int mtk_nor_probe(struct platform_device *pdev) struct spi_controller *ctlr; struct mtk_nor *sp; void __iomem *base; - u8 *buffer; struct clk *spi_clk, *ctlr_clk; int ret, irq; @@ -745,16 +756,6 @@ static int mtk_nor_probe(struct platform_device *pdev) if (IS_ERR(ctlr_clk)) return PTR_ERR(ctlr_clk); - buffer = devm_kmalloc(&pdev->dev, - MTK_NOR_BOUNCE_BUF_SIZE + MTK_NOR_DMA_ALIGN, - GFP_KERNEL); - if (!buffer) - return -ENOMEM; - - if ((ulong)buffer & MTK_NOR_DMA_ALIGN_MASK) - buffer = (u8 *)(((ulong)buffer + MTK_NOR_DMA_ALIGN) & - ~MTK_NOR_DMA_ALIGN_MASK); - ctlr = spi_alloc_master(&pdev->dev, sizeof(*sp)); if (!ctlr) { dev_err(&pdev->dev, "failed to allocate spi controller\n"); @@ -774,13 +775,22 @@ static int mtk_nor_probe(struct platform_device *pdev) sp = spi_controller_get_devdata(ctlr); sp->base = base; - sp->buffer = buffer; sp->has_irq = false; sp->wbuf_en = false; sp->ctlr = ctlr; sp->dev = &pdev->dev; sp->spi_clk = spi_clk; sp->ctlr_clk = ctlr_clk; + sp->buffer = dmam_alloc_coherent(&pdev->dev, + MTK_NOR_BOUNCE_BUF_SIZE + MTK_NOR_DMA_ALIGN, + &sp->buffer_dma, GFP_KERNEL); + if (!sp->buffer) + return -ENOMEM; + + if ((uintptr_t)sp->buffer & MTK_NOR_DMA_ALIGN_MASK) { + dev_err(sp->dev, "misaligned allocation of internal buffer.\n"); + return -ENOMEM; + } irq = platform_get_irq_optional(pdev, 0); if (irq < 0) { -- 2.7.4