[PATCH RFC 2/2] mmc: meson-gx: use sg_copy_to/from_io instead of local version

From: Neil Armstrong
Date: Mon Jun 28 2021 - 08:34:38 EST


Use the proper sg_copy_to_io & sg_copy_from_io instead of having a local
sg_copy_buffer variant to handle the I/O mapped buffer case.

Cc: Robin Murphy <robin.murphy@xxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/mmc/host/meson-gx-mmc.c | 53 +++++++--------------------------
1 file changed, 10 insertions(+), 43 deletions(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 3f28eb4d17fe..c13436efb414 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -746,47 +746,6 @@ 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);
@@ -830,7 +789,12 @@ 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)
+ sg_copy_to_io(data->sg, data->sg_len,
+ host->bounce_iomem_buf, xfer_bytes);
+ else
+ sg_copy_to_buffer(data->sg, data->sg_len,
+ host->bounce_buf, xfer_bytes);
dma_wmb();
}

@@ -999,7 +963,10 @@ 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)
+ sg_copy_from_io(data->sg, data->sg_len, host->bounce_iomem_buf, xfer_bytes);
+ 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