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mmc: meson-gx: do not use memcpy_to/fromio for dram-access-quirk 

The memory at the end of the controller only accepts 32bit read/write
accesses, but the arm64 memcpy_to/fromio implementation only uses 64bit
(which will be split into two 32bit access) and 8bit leading to incomplete
copies to/from this memory when the buffer is not multiple of 8bytes.

Add a local copy using writel/readl accesses to make sure we use the right
memory access width.

The switch to memcpy_to/fromio was done because of 285133040e
("arm64: Import latest memcpy()/memmove() implementation"), but using memcpy
worked before since it mainly used 32bit memory acceses.

Fixes: 103a5348c2 ("mmc: meson-gx: use memcpy_to/fromio for dram-access-quirk")
Reported-by: Christian Hewitt <christianshewitt@gmail.com>
Suggested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210928073652.434690-1-narmstrong@baylibre.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Neil Armstrong 2021-09-28 09:36:52 +02:00 committed by Ulf Hansson
parent 30d4b990ec
commit 8a38a4d51c
1 changed files with 59 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
drivers/mmc/host/meson-gx-mmc.c
View File

@ -746,7 +746,7 @@ 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 */
/* local sg copy for dram_access_quirk */
static void meson_mmc_copy_buffer(struct meson_host *host, struct mmc_data *data,
size_t buflen, bool to_buffer)
{
@ -764,21 +764,27 @@ static void meson_mmc_copy_buffer(struct meson_host *host, struct mmc_data *data
sg_miter_start(&miter, sgl, nents, sg_flags);
while ((offset < buflen) && sg_miter_next(&miter)) {
unsigned int len;
unsigned int buf_offset = 0;
unsigned int len, left;
u32 *buf = miter.addr;
len = min(miter.length, buflen - offset);
left = len;
/* 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);
if (to_buffer) {
do {
writel(*buf++, host->bounce_iomem_buf + offset + buf_offset);
buf_offset += 4;
left -= 4;
} while (left);
} else {
if (to_buffer)
memcpy(host->bounce_buf + offset, miter.addr, len);
else
memcpy(miter.addr, host->bounce_buf + offset, len);
do {
*buf++ = readl(host->bounce_iomem_buf + offset + buf_offset);
buf_offset += 4;
left -= 4;
} while (left);
}
offset += len;
@ -830,7 +836,11 @@ 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);
meson_mmc_copy_buffer(host, data, xfer_bytes, true);
if (host->dram_access_quirk)
meson_mmc_copy_buffer(host, data, xfer_bytes, true);
else
sg_copy_to_buffer(data->sg, data->sg_len,
host->bounce_buf, xfer_bytes);
dma_wmb();
}
@ -849,12 +859,43 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
writel(cmd->arg, host->regs + SD_EMMC_CMD_ARG);
}
static int meson_mmc_validate_dram_access(struct mmc_host *mmc, struct mmc_data *data)
{
struct scatterlist *sg;
int i;
/* Reject request if any element offset or size is not 32bit aligned */
for_each_sg(data->sg, sg, data->sg_len, i) {
if (!IS_ALIGNED(sg->offset, sizeof(u32)) ||
!IS_ALIGNED(sg->length, sizeof(u32))) {
dev_err(mmc_dev(mmc), "unaligned sg offset %u len %u\n",
data->sg->offset, data->sg->length);
return -EINVAL;
}
}
return 0;
}
static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
struct meson_host *host = mmc_priv(mmc);
bool needs_pre_post_req = mrq->data &&
!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
/*
* The memory at the end of the controller used as bounce buffer for
* the dram_access_quirk only accepts 32bit read/write access,
* check the aligment and length of the data before starting the request.
*/
if (host->dram_access_quirk && mrq->data) {
mrq->cmd->error = meson_mmc_validate_dram_access(mmc, mrq->data);
if (mrq->cmd->error) {
mmc_request_done(mmc, mrq);
return;
}
}
if (needs_pre_post_req) {
meson_mmc_get_transfer_mode(mmc, mrq);
if (!meson_mmc_desc_chain_mode(mrq->data))
@ -999,7 +1040,11 @@ 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);
meson_mmc_copy_buffer(host, data, xfer_bytes, false);
if (host->dram_access_quirk)
meson_mmc_copy_buffer(host, data, xfer_bytes, false);
else
sg_copy_from_buffer(data->sg, data->sg_len,
host->bounce_buf, xfer_bytes);
}
next_cmd = meson_mmc_get_next_command(cmd);