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mmc: meson-gx: use memcpy_to/fromio for dram-access-quirk 

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] 285133040e ("arm64: Import latest memcpy()/memmove() implementation")

Fixes: acdc8e71d9 ("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>
This commit is contained in:
Neil Armstrong 2021-06-09 17:02:30 +02:00 committed by Ulf Hansson
parent 009c9aa5be
commit 103a5348c2
1 changed files with 45 additions and 5 deletions
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50
drivers/mmc/host/meson-gx-mmc.c
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@ -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_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);
@ -788,8 +830,7 @@ 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();
}
@ -958,8 +999,7 @@ 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 */