From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 01/11] mmc: davinci: handle highmem pages Date: Mon, 14 Jan 2019 10:57:54 +0100 Message-ID: <20190114095804.27978-2-hch@lst.de> References: <20190114095804.27978-1-hch@lst.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190114095804.27978-1-hch@lst.de> Sender: linux-kernel-owner@vger.kernel.org To: Ulf Hansson Cc: Russell King , Nicolas Pitre , Aaro Koskinen , Ben Dooks , linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org List-Id: linux-mmc@vger.kernel.org Instead of setting up a kernel pointer to track the current PIO address, track the offset in the current page, and do an atomic kmap for the page while doing the actual PIO operations. Signed-off-by: Christoph Hellwig --- drivers/mmc/host/davinci_mmc.c | 43 ++++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c index 9e68c3645e22..9c500c52b63d 100644 --- a/drivers/mmc/host/davinci_mmc.c +++ b/drivers/mmc/host/davinci_mmc.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -194,11 +195,12 @@ struct mmc_davinci_host { #define DAVINCI_MMC_DATADIR_WRITE 2 unsigned char data_dir; - /* buffer is used during PIO of one scatterlist segment, and - * is updated along with buffer_bytes_left. bytes_left applies - * to all N blocks of the PIO transfer. + /* + * buffer_offset is used during PIO of one scatterlist segment, and is + * updated along with buffer_bytes_left. bytes_left applies to all N + * blocks of the PIO transfer. */ - u8 *buffer; + u32 buffer_offset; u32 buffer_bytes_left; u32 bytes_left; @@ -229,8 +231,8 @@ static irqreturn_t mmc_davinci_irq(int irq, void *dev_id); /* PIO only */ static void mmc_davinci_sg_to_buf(struct mmc_davinci_host *host) { + host->buffer_offset = host->sg->offset; host->buffer_bytes_left = sg_dma_len(host->sg); - host->buffer = sg_virt(host->sg); if (host->buffer_bytes_left > host->bytes_left) host->buffer_bytes_left = host->bytes_left; } @@ -238,7 +240,7 @@ static void mmc_davinci_sg_to_buf(struct mmc_davinci_host *host) static void davinci_fifo_data_trans(struct mmc_davinci_host *host, unsigned int n) { - u8 *p; + void *p; unsigned int i; if (host->buffer_bytes_left == 0) { @@ -246,7 +248,7 @@ static void davinci_fifo_data_trans(struct mmc_davinci_host *host, mmc_davinci_sg_to_buf(host); } - p = host->buffer; + p = kmap_atomic(sg_page(host->sg)); if (n > host->buffer_bytes_left) n = host->buffer_bytes_left; host->buffer_bytes_left -= n; @@ -258,24 +260,31 @@ static void davinci_fifo_data_trans(struct mmc_davinci_host *host, */ if (host->data_dir == DAVINCI_MMC_DATADIR_WRITE) { for (i = 0; i < (n >> 2); i++) { - writel(*((u32 *)p), host->base + DAVINCI_MMCDXR); - p = p + 4; + u32 *val = p + host->buffer_offset; + + writel(*val, host->base + DAVINCI_MMCDXR); + host->buffer_offset += 4; } if (n & 3) { - iowrite8_rep(host->base + DAVINCI_MMCDXR, p, (n & 3)); - p = p + (n & 3); + iowrite8_rep(host->base + DAVINCI_MMCDXR, + p + host->buffer_offset, n & 3); + host->buffer_offset += (n & 3); } } else { for (i = 0; i < (n >> 2); i++) { - *((u32 *)p) = readl(host->base + DAVINCI_MMCDRR); - p = p + 4; + u32 *val = p + host->buffer_offset; + + *val = readl(host->base + DAVINCI_MMCDRR); + host->buffer_offset += 4; } if (n & 3) { - ioread8_rep(host->base + DAVINCI_MMCDRR, p, (n & 3)); - p = p + (n & 3); + ioread8_rep(host->base + DAVINCI_MMCDRR, + p + host->buffer_offset, n & 3); + host->buffer_offset += (n & 3); } } - host->buffer = p; + + kunmap_atomic(p); } static void mmc_davinci_start_command(struct mmc_davinci_host *host, @@ -572,7 +581,7 @@ mmc_davinci_prepare_data(struct mmc_davinci_host *host, struct mmc_request *req) host->base + DAVINCI_MMCFIFOCTL); } - host->buffer = NULL; + host->buffer_offset = 0; host->bytes_left = data->blocks * data->blksz; /* For now we try to use DMA whenever we won't need partial FIFO -- 2.20.1