| Message ID | 20210609150230.9291-1-narmstrong@baylibre.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: meson-gx: use memcpy_to/fromio for dram-access-quirk | expand |
On Wed, 9 Jun 2021 at 17:02, Neil Armstrong <narmstrong@baylibre.com> wrote: > > 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. > > 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> > > [1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation") Applied for fixes and by adding a stable tag, thanks! Kind regards Uffe > --- > drivers/mmc/host/meson-gx-mmc.c | 50 +++++++++++++++++++++++++++++---- > 1 file changed, 45 insertions(+), 5 deletions(-) > > > Changes since RFC: > - moved iomem address to bounce_iomem_buf otherwise sparse screamed when feeding memcpy_to/fromio with non iomem pointer > > diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c > index b8b771b643cc..3e9b28f18c70 100644 > --- 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; > @@ -742,6 +743,47 @@ 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); > @@ -785,8 +827,7 @@ 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(); > } > > @@ -955,8 +996,7 @@ 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); > @@ -1176,7 +1216,7 @@ 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 */ > -- > 2.25.1 >
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index b8b771b643cc..3e9b28f18c70 100644 --- 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; @@ -742,6 +743,47 @@ 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); @@ -785,8 +827,7 @@ 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(); } @@ -955,8 +996,7 @@ 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); @@ -1176,7 +1216,7 @@ 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 */
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. 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> [1] 285133040e6c ("arm64: Import latest memcpy()/memmove() implementation") --- drivers/mmc/host/meson-gx-mmc.c | 50 +++++++++++++++++++++++++++++---- 1 file changed, 45 insertions(+), 5 deletions(-) Changes since RFC: - moved iomem address to bounce_iomem_buf otherwise sparse screamed when feeding memcpy_to/fromio with non iomem pointer