In IOMMU environment, since it's possible to merge scatter gather
buffers of memory requests to one iova, this patch changes the max_segs
value when init_card of mmc_host timing to improve the transfer
performance on renesas_sdhi_internal_dmac.
Notes that an sdio card may be possible to use scatter gather buffers
with non page aligned size, so that this driver will not use multiple
segments to avoid any trouble. Also, on renesas_sdhi_sys_dmac,
the max_segs value will change from 32 to 512, but the sys_dmac
can handle 512 segments, so that this init_card ops is added on
"TMIO_MMC_MIN_RCAR2" environment.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
drivers/mmc/host/renesas_sdhi_core.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index 5e9e36e..2f86975 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -46,6 +46,8 @@
#define SDHI_VER_GEN3_SD 0xcc10
#define SDHI_VER_GEN3_SDMMC 0xcd10
+#define SDHI_MAX_SEGS_IN_IOMMU 512
+
struct renesas_sdhi_quirks {
bool hs400_disabled;
bool hs400_4taps;
@@ -203,6 +205,27 @@ static void renesas_sdhi_clk_disable(struct tmio_mmc_host *host)
clk_disable_unprepare(priv->clk_cd);
}
+static void renesas_sdhi_init_card(struct mmc_host *mmc, struct mmc_card *card)
+{
+ struct tmio_mmc_host *host = mmc_priv(mmc);
+
+ /*
+ * In IOMMU environment, it's possible to merge scatter gather buffers
+ * of memory requests to one iova so that this code changes
+ * the max_segs when init_card of mmc_host timing. Notes that an sdio
+ * card may be possible to use scatter gather buffers with non page
+ * aligned size, so that this driver will not use multiple segments
+ * to avoid any trouble even if IOMMU environment.
+ */
+ if (host->pdata->max_segs < SDHI_MAX_SEGS_IN_IOMMU &&
+ host->pdev->dev.iommu_group &&
+ (mmc_card_mmc(card) || mmc_card_sd(card)))
+ host->mmc->max_segs = SDHI_MAX_SEGS_IN_IOMMU;
+ else
+ host->mmc->max_segs = host->pdata->max_segs ? :
+ TMIO_DEFAULT_MAX_SEGS;
+}
+
static int renesas_sdhi_card_busy(struct mmc_host *mmc)
{
struct tmio_mmc_host *host = mmc_priv(mmc);
@@ -726,6 +749,8 @@ int renesas_sdhi_probe(struct platform_device *pdev,
/* SDR speeds are only available on Gen2+ */
if (mmc_data->flags & TMIO_MMC_MIN_RCAR2) {
+ host->ops.init_card = renesas_sdhi_init_card;
+
/* card_busy caused issues on r8a73a4 (pre-Gen2) CD-less SDHI */
host->ops.card_busy = renesas_sdhi_card_busy;
host->ops.start_signal_voltage_switch =
--
2.7.4
