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authorStephen Warren <swarren@nvidia.com>2012-11-06 11:27:30 +0000
committerAndy Fleming <afleming@freescale.com>2012-11-27 17:26:49 -0600
commit1981539914b3626efe4a97bde19ec5fe548b50cf (patch)
tree22f64db46571f7765bfcfd39bccc57ad1d86e18a /drivers
parent84d35b2863455bedb9986c2b076241e8a441fc3e (diff)
downloadu-boot-linaro-stable-1981539914b3626efe4a97bde19ec5fe548b50cf.tar.gz
mmc: tegra: use bounce buffer APIs
Tegra's MMC driver does DMA, and hence needs cache-aligned buffers. In some cases (e.g. user load commands) this cannot be guaranteed by callers of the MMC APIs. To solve this, modify the Tegra MMC driver to use the new bounce_buffer_*() APIs. Note: Ideally, all U-Boot code will always provide address- and size- aligned buffers, so a bounce buffer will only ever be needed for user- supplied buffers (e.g. load commands). Ensuring this removes the need for performance-sucking bounce buffer cache management and memcpy()s. The one known exception at present is the SCR buffer in sd_change_freq(), which is only 8 bytes long. Solving this requires enhancing struct mmc_data to know the difference between buffer size and transferred data size, or forcing all callers of mmc_send_cmd() to have allocated buffers using ALLOC_CACHE_ALIGN_BUFFER(), which while true in this case, is not enforced in any way at present, and so cannot be assumed by the core MMC code. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Simon Glass <sjg@chromium.org> Tested-by: Simon Glass <sjg@chromium.org> Signed-off-by: Andy Fleming <afleming@freescale.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mmc/tegra_mmc.c64
1 files changed, 41 insertions, 23 deletions
diff --git a/drivers/mmc/tegra_mmc.c b/drivers/mmc/tegra_mmc.c
index 8fea6a6bf..b141eafc7 100644
--- a/drivers/mmc/tegra_mmc.c
+++ b/drivers/mmc/tegra_mmc.c
@@ -19,6 +19,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <bouncebuf.h>
#include <common.h>
#include <asm/gpio.h>
#include <asm/io.h>
@@ -66,14 +67,17 @@ static void tegra_get_setup(struct mmc_host *host, int dev_index)
host->reg = (struct tegra_mmc *)host->base;
}
-static void mmc_prepare_data(struct mmc_host *host, struct mmc_data *data)
+static void mmc_prepare_data(struct mmc_host *host, struct mmc_data *data,
+ struct bounce_buffer *bbstate)
{
unsigned char ctrl;
- debug("data->dest: %08X, data->blocks: %u, data->blocksize: %u\n",
- (u32)data->dest, data->blocks, data->blocksize);
- writel((u32)data->dest, &host->reg->sysad);
+ debug("buf: %p (%p), data->blocks: %u, data->blocksize: %u\n",
+ bbstate->bounce_buffer, bbstate->user_buffer, data->blocks,
+ data->blocksize);
+
+ writel((u32)bbstate->bounce_buffer, &host->reg->sysad);
/*
* DMASEL[4:3]
* 00 = Selects SDMA
@@ -114,14 +118,6 @@ static void mmc_set_transfer_mode(struct mmc_host *host, struct mmc_data *data)
if (data->flags & MMC_DATA_READ)
mode |= TEGRA_MMC_TRNMOD_DATA_XFER_DIR_SEL_READ;
- if (data->flags & MMC_DATA_WRITE) {
- if ((uintptr_t)data->src & (ARCH_DMA_MINALIGN - 1))
- printf("Warning: unaligned write to %p may fail\n",
- data->src);
- flush_dcache_range((ulong)data->src, (ulong)data->src +
- data->blocks * data->blocksize);
- }
-
writew(mode, &host->reg->trnmod);
}
@@ -156,8 +152,8 @@ static int mmc_wait_inhibit(struct mmc_host *host,
return 0;
}
-static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
- struct mmc_data *data)
+static int mmc_send_cmd_bounced(struct mmc *mmc, struct mmc_cmd *cmd,
+ struct mmc_data *data, struct bounce_buffer *bbstate)
{
struct mmc_host *host = (struct mmc_host *)mmc->priv;
int flags, i;
@@ -172,7 +168,7 @@ static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
return result;
if (data)
- mmc_prepare_data(host, data);
+ mmc_prepare_data(host, data, bbstate);
debug("cmd->arg: %08x\n", cmd->cmdarg);
writel(cmd->cmdarg, &host->reg->argument);
@@ -322,20 +318,42 @@ static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
}
}
writel(mask, &host->reg->norintsts);
- if (data->flags & MMC_DATA_READ) {
- if ((uintptr_t)data->dest & (ARCH_DMA_MINALIGN - 1))
- printf("Warning: unaligned read from %p "
- "may fail\n", data->dest);
- invalidate_dcache_range((ulong)data->dest,
- (ulong)data->dest +
- data->blocks * data->blocksize);
- }
}
udelay(1000);
return 0;
}
+static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
+ struct mmc_data *data)
+{
+ void *buf;
+ unsigned int bbflags;
+ size_t len;
+ struct bounce_buffer bbstate;
+ int ret;
+
+ if (data) {
+ if (data->flags & MMC_DATA_READ) {
+ buf = data->dest;
+ bbflags = GEN_BB_WRITE;
+ } else {
+ buf = (void *)data->src;
+ bbflags = GEN_BB_READ;
+ }
+ len = data->blocks * data->blocksize;
+
+ bounce_buffer_start(&bbstate, buf, len, bbflags);
+ }
+
+ ret = mmc_send_cmd_bounced(mmc, cmd, data, &bbstate);
+
+ if (data)
+ bounce_buffer_stop(&bbstate);
+
+ return ret;
+}
+
static void mmc_change_clock(struct mmc_host *host, uint clock)
{
int div;