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 285133040e6c
("arm64: Import latest memcpy()/memmove() implementation"), but using memcpy
worked before since it mainly used 32bit memory acceses.
Fixes: 103a5348c22c ("mmc: meson-gx: use memcpy_to/fromio for dram-access-quirk")
Reported-by: Christian Hewitt <christianshewitt@xxxxxxxxx>
Suggested-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/mmc/host/meson-gx-mmc.c | 49 +++++++++++++++++++++++----------
1 file changed, 35 insertions(+), 14 deletions(-)
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 3f28eb4d17fe..08c0ff0bfa8b 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -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 +764,34 @@ 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;
+
+ if (((unsigned long int)miter.addr % 4))
+ dev_err(host->dev, "non word aligned sg");
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);
+ if ((len % 4))
+ dev_err(host->dev, "non word multiple sg");
+
+ left = 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 +843,11 @@ 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();
}
@@ -999,7 +1016,11 @@ 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);
--
2.25.1
