From: Neil Armstrong narmstrong@baylibre.com
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@samsung.com Suggested-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Neil Armstrong narmstrong@baylibre.com Tested-by: Marek Szyprowski m.szyprowski@samsung.com Link: https://lore.kernel.org/r/20210609150230.9291-1-narmstrong@baylibre.com Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mmc/host/meson-gx-mmc.c | 50 +++++++++++++++++++++++++++++---- 1 file changed, 45 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index 545c3f2f8a06..a3e3b274f0ea 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -166,6 +166,7 @@ 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; @@ -737,6 +738,47 @@ static void meson_mmc_desc_chain_transfer(struct mmc_host *mmc, u32 cmd_cfg) 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); @@ -780,8 +822,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd) 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(); }
@@ -950,8 +991,7 @@ static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id) 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 platform_device *pdev) * 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 */