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 <hch@xxxxxx> --- drivers/mmc/host/omap.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c index c60a7625b1fa..6741c95f2281 100644 --- a/drivers/mmc/host/omap.c +++ b/drivers/mmc/host/omap.c @@ -148,7 +148,7 @@ struct mmc_omap_host { unsigned int sg_len; int sg_idx; - u16 * buffer; + u32 buffer_offset; u32 buffer_bytes_left; u32 total_bytes_left; @@ -649,7 +649,7 @@ mmc_omap_sg_to_buf(struct mmc_omap_host *host) sg = host->data->sg + host->sg_idx; host->buffer_bytes_left = sg->length; - host->buffer = sg_virt(sg); + host->buffer_offset = sg->offset; if (host->buffer_bytes_left > host->total_bytes_left) host->buffer_bytes_left = host->total_bytes_left; } @@ -666,7 +666,9 @@ mmc_omap_clk_timer(struct timer_list *t) static void mmc_omap_xfer_data(struct mmc_omap_host *host, int write) { + struct scatterlist *sg = host->data->sg + host->sg_idx; int n, nwords; + void *p; if (host->buffer_bytes_left == 0) { host->sg_idx++; @@ -684,15 +686,17 @@ mmc_omap_xfer_data(struct mmc_omap_host *host, int write) host->total_bytes_left -= n; host->data->bytes_xfered += n; + p = sg_kmap_atomic(sg); if (write) { __raw_writesw(host->virt_base + OMAP_MMC_REG(host, DATA), - host->buffer, nwords); + p + host->buffer_offset, nwords); } else { __raw_readsw(host->virt_base + OMAP_MMC_REG(host, DATA), - host->buffer, nwords); + p + host->buffer_offset, nwords); } + sg_kunmap_atomic(sg, p); - host->buffer += nwords; + host->buffer_offset += nwords; } #ifdef CONFIG_MMC_DEBUG @@ -1250,6 +1254,7 @@ static int mmc_omap_new_slot(struct mmc_omap_host *host, int id) mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_ERASE; mmc->ops = &mmc_omap_ops; + mmc->need_kmap = 1; mmc->f_min = 400000; if (mmc_omap2()) -- 2.20.1