This is a note to let you know that I've just added the patch titled mmc: meson-gx: use memcpy_to/fromio for dram-access-quirk to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mmc-meson-gx-use-memcpy_to-fromio-for-dram-access-quirk.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 103a5348c22c3fca8b96c735a9e353b8a0801842 Mon Sep 17 00:00:00 2001 From: Neil Armstrong <narmstrong@xxxxxxxxxxxx> Date: Wed, 9 Jun 2021 17:02:30 +0200 Subject: mmc: meson-gx: use memcpy_to/fromio for dram-access-quirk From: Neil Armstrong <narmstrong@xxxxxxxxxxxx> commit 103a5348c22c3fca8b96c735a9e353b8a0801842 upstream. It has been reported that usage of memcpy() to/from an iomem mapping is invalid, and a recent arm64 memcpy update [1] triggers a memory abort when dram-access-quirk is used on the G12A/G12B platforms. This adds a local sg_copy_to_buffer which makes usage of io versions of memcpy when dram-access-quirk is enabled. [1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation") Fixes: acdc8e71d9bb ("mmc: meson-gx: add dram-access-quirk") Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Suggested-by: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx> Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20210609150230.9291-1-narmstrong@xxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mmc/host/meson-gx-mmc.c | 50 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 45 insertions(+), 5 deletions(-) --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -165,6 +165,7 @@ struct meson_host { unsigned int bounce_buf_size; void *bounce_buf; + void __iomem *bounce_iomem_buf; dma_addr_t bounce_dma_addr; struct sd_emmc_desc *descs; dma_addr_t descs_dma_addr; @@ -745,6 +746,47 @@ static void meson_mmc_desc_chain_transfe writel(start, host->regs + SD_EMMC_START); } +/* local sg copy to buffer version with _to/fromio usage for dram_access_quirk */ +static void meson_mmc_copy_buffer(struct meson_host *host, struct mmc_data *data, + size_t buflen, bool to_buffer) +{ + unsigned int sg_flags = SG_MITER_ATOMIC; + struct scatterlist *sgl = data->sg; + unsigned int nents = data->sg_len; + struct sg_mapping_iter miter; + unsigned int offset = 0; + + if (to_buffer) + sg_flags |= SG_MITER_FROM_SG; + else + sg_flags |= SG_MITER_TO_SG; + + sg_miter_start(&miter, sgl, nents, sg_flags); + + while ((offset < buflen) && sg_miter_next(&miter)) { + unsigned int len; + + len = min(miter.length, buflen - offset); + + /* When dram_access_quirk, the bounce buffer is a iomem mapping */ + if (host->dram_access_quirk) { + if (to_buffer) + memcpy_toio(host->bounce_iomem_buf + offset, miter.addr, len); + else + memcpy_fromio(miter.addr, host->bounce_iomem_buf + offset, len); + } else { + if (to_buffer) + memcpy(host->bounce_buf + offset, miter.addr, len); + else + memcpy(miter.addr, host->bounce_buf + offset, len); + } + + offset += len; + } + + sg_miter_stop(&miter); +} + static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) { struct meson_host *host = mmc_priv(mmc); @@ -788,8 +830,7 @@ static void meson_mmc_start_cmd(struct m 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); + meson_mmc_copy_buffer(host, data, xfer_bytes, true); dma_wmb(); } @@ -958,8 +999,7 @@ static irqreturn_t meson_mmc_irq_thread( if (meson_mmc_bounce_buf_read(data)) { 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); + meson_mmc_copy_buffer(host, data, xfer_bytes, false); } next_cmd = meson_mmc_get_next_command(cmd); @@ -1179,7 +1219,7 @@ static int meson_mmc_probe(struct platfo * instead of the DDR memory */ host->bounce_buf_size = SD_EMMC_SRAM_DATA_BUF_LEN; - host->bounce_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF; + host->bounce_iomem_buf = host->regs + SD_EMMC_SRAM_DATA_BUF_OFF; host->bounce_dma_addr = res->start + SD_EMMC_SRAM_DATA_BUF_OFF; } else { /* data bounce buffer */ Patches currently in stable-queue which might be from narmstrong@xxxxxxxxxxxx are queue-5.12/mmc-meson-gx-use-memcpy_to-fromio-for-dram-access-quirk.patch