>From 3433341319cab08552ab7c8225bcf3b6c4770a02 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Tue, 28 Mar 2017 21:05:53 +0200 Subject: [PATCH 4/4] change to desc chain mode Signed-off-by: Heiner Kallweit --- drivers/mmc/host/meson-gx-mmc.c | 143 ++++++++++++++++++++++++---------------- 1 file changed, 87 insertions(+), 56 deletions(-) diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index 0036680b..1a64cb91 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -109,8 +109,16 @@ #define SD_EMMC_CMD_TIMEOUT 1024 /* in ms */ #define SD_EMMC_CMD_TIMEOUT_DATA 4096 /* in ms */ #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */ +#define SD_EMMC_DESC_BUF_LEN PAGE_SIZE #define MUX_CLK_NUM_PARENTS 2 +struct sd_emmc_desc { + u32 cmd_cfg; + u32 cmd_arg; + u32 cmd_data; + u32 cmd_resp; +}; + struct meson_host { struct device *dev; struct mmc_host *mmc; @@ -126,20 +134,12 @@ struct meson_host { struct clk_divider cfg_div; struct clk *cfg_div_clk; - unsigned int bounce_buf_size; - void *bounce_buf; - dma_addr_t bounce_dma_addr; + struct sd_emmc_desc *descs; + dma_addr_t descs_dma_addr; bool vqmmc_enabled; }; -struct sd_emmc_desc { - u32 cmd_cfg; - u32 cmd_arg; - u32 cmd_data; - u32 cmd_resp; -}; - #define CMD_CFG_LENGTH_MASK GENMASK(8, 0) #define CMD_CFG_BLOCK_MODE BIT(9) #define CMD_CFG_R1B BIT(10) @@ -186,6 +186,31 @@ static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd) return NULL; } +static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq) +{ + struct mmc_data *data = mrq->data; + + if (!data) + return; + + data->host_cookie = true; + + data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg, data->sg_len, + mmc_get_dma_dir(data)); + if (!data->sg_count) + dev_err(mmc_dev(mmc), "dma_map_sg failed"); +} + +static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq, + int err) +{ + struct mmc_data *data = mrq->data; + + if (data && data->sg_count) + dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len, + mmc_get_dma_dir(data)); +} + static int meson_mmc_clk_set(struct meson_host *host, unsigned long clk_rate) { struct mmc_host *mmc = host->mmc; @@ -476,9 +501,11 @@ static void meson_mmc_set_response_bits(struct mmc_command *cmd, u32 *cmd_cfg) static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) { struct meson_host *host = mmc_priv(mmc); + struct sd_emmc_desc *desc = host->descs; struct mmc_data *data = cmd->data; - u32 cmd_cfg = 0, cmd_data = 0; - unsigned int xfer_bytes = 0; + u32 cfg, cmd_cfg = 0; + struct scatterlist *sg; + int i; /* Setup descriptors */ dma_rmb(); @@ -490,57 +517,68 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) /* data? */ if (data) { + data->bytes_xfered = 0; cmd_cfg |= CMD_CFG_DATA_IO; cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK, ilog2(meson_mmc_get_timeout_msecs(data))); + if (data->flags & MMC_DATA_WRITE) + cmd_cfg |= CMD_CFG_DATA_WR; if (data->blocks > 1) { cmd_cfg |= CMD_CFG_BLOCK_MODE; - cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, - data->blocks); meson_mmc_set_blksz(mmc, data->blksz); - } else { - cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, data->blksz); } - data->bytes_xfered = 0; - xfer_bytes = data->blksz * data->blocks; - if (data->flags & MMC_DATA_WRITE) { - cmd_cfg |= CMD_CFG_DATA_WR; - WARN_ON(xfer_bytes > host->bounce_buf_size); - sg_copy_to_buffer(data->sg, data->sg_len, - host->bounce_buf, xfer_bytes); - dma_wmb(); - } + for_each_sg(data->sg, sg, data->sg_count, i) { + unsigned int len = sg_dma_len(sg); + + /* check proper alignment for 64 bit DMA */ + WARN_ON(sg_dma_address(sg) & 0x7); - cmd_data = host->bounce_dma_addr & CMD_DATA_MASK; + if (data->blocks > 1) + len /= data->blksz; + + desc[i].cmd_cfg = cmd_cfg; + desc[i].cmd_cfg |= FIELD_PREP(CMD_CFG_LENGTH_MASK, len); + if (i > 0) + desc[i].cmd_cfg |= CMD_CFG_NO_CMD; + desc[i].cmd_arg = cmd->arg; + desc[i].cmd_resp = 0; + desc[i].cmd_data = sg_dma_address(sg); + } + desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN; } else { cmd_cfg |= FIELD_PREP(CMD_CFG_TIMEOUT_MASK, ilog2(SD_EMMC_CMD_TIMEOUT)); + cmd_cfg |= CMD_CFG_END_OF_CHAIN; + desc[0].cmd_cfg = cmd_cfg; + desc[0].cmd_arg = cmd->arg; + desc[0].cmd_resp = 0; + desc[0].cmd_data = 0; } host->cmd = cmd; - /* Last descriptor */ - cmd_cfg |= CMD_CFG_END_OF_CHAIN; - writel(cmd_cfg, host->regs + SD_EMMC_CMD_CFG); - writel(cmd_data, host->regs + SD_EMMC_CMD_DAT); - writel(0, host->regs + SD_EMMC_CMD_RSP); wmb(); /* ensure descriptor is written before kicked */ - writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG); + cfg = host->descs_dma_addr | START_DESC_BUSY; + writel(cfg, host->regs + SD_EMMC_START); } static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) { struct meson_host *host = mmc_priv(mmc); + bool needs_pre_post_req = mrq->data && !mrq->data->host_cookie; + + if (needs_pre_post_req) + meson_mmc_pre_req(mmc, mrq); /* Stop execution */ writel(0, host->regs + SD_EMMC_START); - if (mrq->sbc) - meson_mmc_start_cmd(mmc, mrq->sbc); - else - meson_mmc_start_cmd(mmc, mrq->cmd); + meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd); + + if (needs_pre_post_req) + meson_mmc_post_req(mmc, mrq, 0); } static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd) @@ -618,7 +656,9 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id) if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) { if (data && !cmd->error) data->bytes_xfered = data->blksz * data->blocks; - ret = IRQ_WAKE_THREAD; + + if (meson_mmc_get_next_command(cmd)) + ret = IRQ_WAKE_THREAD; } else { dev_warn(host->dev, "Unknown IRQ! status=0x%04x: MMC CMD%u arg=0x%08x flags=0x%08x stop=%d\n", status, cmd->opcode, cmd->arg, @@ -648,20 +688,10 @@ static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id) { struct meson_host *host = dev_id; struct mmc_command *next_cmd, *cmd = host->cmd; - struct mmc_data *data; - unsigned int xfer_bytes; if (WARN_ON(!cmd)) return IRQ_NONE; - data = cmd->data; - if (data && data->flags & MMC_DATA_READ) { - xfer_bytes = data->blksz * data->blocks; - WARN_ON(xfer_bytes > host->bounce_buf_size); - sg_copy_from_buffer(data->sg, data->sg_len, - host->bounce_buf, xfer_bytes); - } - next_cmd = meson_mmc_get_next_command(cmd); if (next_cmd) meson_mmc_start_cmd(host->mmc, next_cmd); @@ -701,6 +731,8 @@ static const struct mmc_host_ops meson_mmc_ops = { .request = meson_mmc_request, .set_ios = meson_mmc_set_ios, .get_cd = meson_mmc_get_cd, + .pre_req = meson_mmc_pre_req, + .post_req = meson_mmc_post_req, }; static int meson_mmc_probe(struct platform_device *pdev) @@ -781,14 +813,13 @@ static int meson_mmc_probe(struct platform_device *pdev) mmc->caps |= MMC_CAP_CMD23; mmc->max_blk_count = CMD_CFG_LENGTH_MASK; mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size; + mmc->max_segs = SD_EMMC_DESC_BUF_LEN / sizeof(struct sd_emmc_desc); + mmc->max_seg_size = mmc->max_req_size; - /* data bounce buffer */ - host->bounce_buf_size = mmc->max_req_size; - host->bounce_buf = - dma_alloc_coherent(host->dev, host->bounce_buf_size, - &host->bounce_dma_addr, GFP_KERNEL); - if (host->bounce_buf == NULL) { - dev_err(host->dev, "Unable to map allocate DMA bounce buffer.\n"); + host->descs = dma_alloc_coherent(host->dev, SD_EMMC_DESC_BUF_LEN, + &host->descs_dma_addr, GFP_KERNEL); + if (!host->descs) { + dev_err(host->dev, "Allocating descriptor DMA buffer failed\n"); ret = -ENOMEM; goto err_div_clk; } @@ -816,8 +847,8 @@ static int meson_mmc_remove(struct platform_device *pdev) /* disable interrupts */ writel(0, host->regs + SD_EMMC_IRQ_EN); - dma_free_coherent(host->dev, host->bounce_buf_size, - host->bounce_buf, host->bounce_dma_addr); + dma_free_coherent(host->dev, SD_EMMC_DESC_BUF_LEN, + host->descs, host->descs_dma_addr); clk_disable_unprepare(host->cfg_div_clk); clk_disable_unprepare(host->core_clk); -- 2.12.1