Use kmap_local_page() instead of sg_virt() to obtain a page from the scatterlist: sg_virt() will not perform bounce buffering if the page happens to be located in high memory, which the driver may or may not be using. Suggested-by: Christoph Hellwig <hch@xxxxxx> Link: https://lore.kernel.org/linux-mmc/20240122073423.GA25859@xxxxxx/ Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx> --- drivers/mmc/host/mxcmmc.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c index 5b3ab0e20505..04c0e4ea02ff 100644 --- a/drivers/mmc/host/mxcmmc.c +++ b/drivers/mmc/host/mxcmmc.c @@ -267,10 +267,14 @@ static inline void buffer_swap32(u32 *buf, int len) static void mxcmci_swap_buffers(struct mmc_data *data) { struct scatterlist *sg; + u32 *buf; int i; - for_each_sg(data->sg, sg, data->sg_len, i) - buffer_swap32(sg_virt(sg), sg->length); + for_each_sg(data->sg, sg, data->sg_len, i) { + buf = kmap_local_page(sg_page(sg)); + buffer_swap32(buf, sg->length); + kunmap_local(buf); + } } #else static inline void mxcmci_swap_buffers(struct mmc_data *data) {} @@ -526,10 +530,9 @@ static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask) } while (1); } -static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes) +static int mxcmci_pull(struct mxcmci_host *host, u32 *buf, int bytes) { unsigned int stat; - u32 *buf = _buf; while (bytes > 3) { stat = mxcmci_poll_status(host, @@ -555,10 +558,9 @@ static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes) return 0; } -static int mxcmci_push(struct mxcmci_host *host, void *_buf, int bytes) +static int mxcmci_push(struct mxcmci_host *host, u32 *buf, int bytes) { unsigned int stat; - u32 *buf = _buf; while (bytes > 3) { stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY); @@ -588,20 +590,25 @@ static int mxcmci_transfer_data(struct mxcmci_host *host) struct mmc_data *data = host->req->data; struct scatterlist *sg; int stat, i; + u32 *buf; host->data = data; host->datasize = 0; if (data->flags & MMC_DATA_READ) { for_each_sg(data->sg, sg, data->sg_len, i) { - stat = mxcmci_pull(host, sg_virt(sg), sg->length); + buf = kmap_local_page(sg_page(sg)); + stat = mxcmci_pull(host, buf, sg->length); + kunmap_local(buf); if (stat) return stat; host->datasize += sg->length; } } else { for_each_sg(data->sg, sg, data->sg_len, i) { - stat = mxcmci_push(host, sg_virt(sg), sg->length); + buf = kmap_local_page(sg_page(sg)); + stat = mxcmci_push(host, buf, sg->length); + kunmap_local(buf); if (stat) return stat; host->datasize += sg->length; -- 2.34.1
