mmc: sdhci: use dma_map_single() instead of flush_cache() before DMA
Currently, sdhci_prepare_dma() calls flush_cache() regardless of the
DMA direction.
Actually, cache invalidation is enough when reading data from the device.
This is correctly handled by dma_map_single(), which mimics the DMA-API
in Linux kernel. Drivers can be agnostic which cache operation occurs
behind the scene.
This commit also sanitizes the difference between the virtual address
and the dma address.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index ee54d78..77a88bc 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -15,6 +15,7 @@
#include <mmc.h>
#include <sdhci.h>
#include <dm.h>
+#include <linux/dma-mapping.h>
static void sdhci_reset(struct sdhci_host *host, u8 mask)
{
@@ -65,8 +66,8 @@
}
#if CONFIG_IS_ENABLED(MMC_SDHCI_ADMA)
-static void sdhci_adma_desc(struct sdhci_host *host, char *buf, u16 len,
- bool end)
+static void sdhci_adma_desc(struct sdhci_host *host, dma_addr_t dma_addr,
+ u16 len, bool end)
{
struct sdhci_adma_desc *desc;
u8 attr;
@@ -82,9 +83,9 @@
desc->attr = attr;
desc->len = len;
desc->reserved = 0;
- desc->addr_lo = (dma_addr_t)buf;
+ desc->addr_lo = lower_32_bits(dma_addr);
#ifdef CONFIG_DMA_ADDR_T_64BIT
- desc->addr_hi = (u64)buf >> 32;
+ desc->addr_hi = upper_32_bits(dma_addr);
#endif
}
@@ -94,22 +95,17 @@
uint trans_bytes = data->blocksize * data->blocks;
uint desc_count = DIV_ROUND_UP(trans_bytes, ADMA_MAX_LEN);
int i = desc_count;
- char *buf;
+ dma_addr_t dma_addr = host->start_addr;
host->desc_slot = 0;
- if (data->flags & MMC_DATA_READ)
- buf = data->dest;
- else
- buf = (char *)data->src;
-
while (--i) {
- sdhci_adma_desc(host, buf, ADMA_MAX_LEN, false);
- buf += ADMA_MAX_LEN;
+ sdhci_adma_desc(host, dma_addr, ADMA_MAX_LEN, false);
+ dma_addr += ADMA_MAX_LEN;
trans_bytes -= ADMA_MAX_LEN;
}
- sdhci_adma_desc(host, buf, trans_bytes, true);
+ sdhci_adma_desc(host, dma_addr, trans_bytes, true);
flush_cache((dma_addr_t)host->adma_desc_table,
ROUND(desc_count * sizeof(struct sdhci_adma_desc),
@@ -125,11 +121,12 @@
int *is_aligned, int trans_bytes)
{
unsigned char ctrl;
+ void *buf;
if (data->flags == MMC_DATA_READ)
- host->start_addr = (dma_addr_t)data->dest;
+ buf = data->dest;
else
- host->start_addr = (dma_addr_t)data->src;
+ buf = (void *)data->src;
ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
ctrl &= ~SDHCI_CTRL_DMA_MASK;
@@ -139,16 +136,20 @@
ctrl |= SDHCI_CTRL_ADMA32;
sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+ if (host->flags & USE_SDMA &&
+ (host->force_align_buffer ||
+ (host->quirks & SDHCI_QUIRK_32BIT_DMA_ADDR &&
+ ((unsigned long)buf & 0x7) != 0x0))) {
+ *is_aligned = 0;
+ if (data->flags != MMC_DATA_READ)
+ memcpy(host->align_buffer, buf, trans_bytes);
+ buf = host->align_buffer;
+ }
+
+ host->start_addr = dma_map_single(buf, trans_bytes,
+ mmc_get_dma_dir(data));
+
if (host->flags & USE_SDMA) {
- if (host->force_align_buffer ||
- (host->quirks & SDHCI_QUIRK_32BIT_DMA_ADDR &&
- (host->start_addr & 0x7) != 0x0)) {
- *is_aligned = 0;
- host->start_addr = (unsigned long)host->align_buffer;
- if (data->flags != MMC_DATA_READ)
- memcpy(host->align_buffer, data->src,
- trans_bytes);
- }
sdhci_writel(host, host->start_addr, SDHCI_DMA_ADDRESS);
} else if (host->flags & (USE_ADMA | USE_ADMA64)) {
sdhci_prepare_adma_table(host, data);
@@ -159,8 +160,6 @@
sdhci_writel(host, upper_32_bits(host->adma_addr),
SDHCI_ADMA_ADDRESS_HI);
}
-
- flush_cache(host->start_addr, ROUND(trans_bytes, ARCH_DMA_MINALIGN));
}
#else
static void sdhci_prepare_dma(struct sdhci_host *host, struct mmc_data *data,