mmc: dcache: allocate cache aligned buffer for scr and switch_status

Currently the sd_change_freq function allocates two buffers on the
stack that it passes down to the MMC device driver.  These buffers
could be unaligned to the L1 dcache line size.  This causes problems
when using DMA and with caches enabled.

This patch correctly cache alignes the buffers used for reading the
scr register and switch status values from an MMC device.

Change-Id: Ifa8414f572ef907681bd2d5ff3950285a215357d
Signed-off-by: Anton Staaf <robotboy@chromium.org>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>
Acked-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 391bc2bafa0f3393d377425d995ac9939fc1831b..ba6fbfe7ac2d1156b6d39040f7a012b9b2cbab9c 100644 (file)
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -702,8 +702,8 @@ int sd_change_freq(struct mmc *mmc)
 {
        int err;
        struct mmc_cmd cmd;
-       uint scr[2];
-       uint switch_status[16];
+       ALLOC_CACHE_ALIGN_BUFFER(uint, scr, 2);
+       ALLOC_CACHE_ALIGN_BUFFER(uint, switch_status, 16);
        struct mmc_data data;
        int timeout;
 
@@ -731,7 +731,7 @@ int sd_change_freq(struct mmc *mmc)
        timeout = 3;
 
 retry_scr:
-       data.dest = (char *)&scr;
+       data.dest = (char *)scr;
        data.blocksize = 8;
        data.blocks = 1;
        data.flags = MMC_DATA_READ;
@@ -773,7 +773,7 @@ retry_scr:
        timeout = 4;
        while (timeout--) {
                err = sd_switch(mmc, SD_SWITCH_CHECK, 0, 1,
-                               (u8 *)&switch_status);
+                               (u8 *)switch_status);
 
                if (err)
                        return err;
@@ -787,7 +787,7 @@ retry_scr:
        if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED))
                return 0;
 
-       err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)&switch_status);
+       err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status);
 
        if (err)
                return err;