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authorHeiner Kallweit <hkallweit1@gmail.com>2017-03-29 18:54:37 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-10-08 08:26:08 (GMT)
commit727a153435fa431c3c99cf5718976bdb73702d06 (patch)
tree8b7729920b8c6666361e8624501c59980c5bed26
parent8f9bd136b50b15e1ddf12281b34802e948023619 (diff)
downloadlinux-727a153435fa431c3c99cf5718976bdb73702d06.tar.xz
mmc: sdio: fix alignment issue in struct sdio_func
[ Upstream commit 5ef1ecf060f28ecef313b5723f1fd39bf5a35f56 ] Certain 64-bit systems (e.g. Amlogic Meson GX) require buffers to be used for DMA to be 8-byte-aligned. struct sdio_func has an embedded small DMA buffer not meeting this requirement. When testing switching to descriptor chain mode in meson-gx driver SDIO is broken therefore. Fix this by allocating the small DMA buffer separately as kmalloc ensures that the returned memory area is properly aligned for every basic data type. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Tested-by: Helmut Klein <hgkr.klein@gmail.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/mmc/core/sdio_bus.c12
-rw-r--r--include/linux/mmc/sdio_func.h2
2 files changed, 12 insertions, 2 deletions
diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
index 86f5b32..d56a3b6 100644
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -266,7 +266,7 @@ static void sdio_release_func(struct device *dev)
sdio_free_func_cis(func);
kfree(func->info);
-
+ kfree(func->tmpbuf);
kfree(func);
}
@@ -281,6 +281,16 @@ struct sdio_func *sdio_alloc_func(struct mmc_card *card)
if (!func)
return ERR_PTR(-ENOMEM);
+ /*
+ * allocate buffer separately to make sure it's properly aligned for
+ * DMA usage (incl. 64 bit DMA)
+ */
+ func->tmpbuf = kmalloc(4, GFP_KERNEL);
+ if (!func->tmpbuf) {
+ kfree(func);
+ return ERR_PTR(-ENOMEM);
+ }
+
func->card = card;
device_initialize(&func->dev);
diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h
index aab032a..97ca105 100644
--- a/include/linux/mmc/sdio_func.h
+++ b/include/linux/mmc/sdio_func.h
@@ -53,7 +53,7 @@ struct sdio_func {
unsigned int state; /* function state */
#define SDIO_STATE_PRESENT (1<<0) /* present in sysfs */
- u8 tmpbuf[4]; /* DMA:able scratch buffer */
+ u8 *tmpbuf; /* DMA:able scratch buffer */
unsigned num_info; /* number of info strings */
const char **info; /* info strings */