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authorHeiner Kallweit <hkallweit1@gmail.com>2017-03-29 21:54:37 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-10-08 11:11:21 +0300
commit0fe19e5c661621932a511b36143b25a0294e9ff5 (patch)
tree581e8737b48a11d8a4e7b5d5b772118aa9f634cb
parent0ee6c8e7875807fff8f776a50b2299cfa8a7d6ec (diff)
downloadlinux-0fe19e5c661621932a511b36143b25a0294e9ff5.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 6da97b170563..8d246f815658 100644
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -265,7 +265,7 @@ static void sdio_release_func(struct device *dev)
sdio_free_func_cis(func);
kfree(func->info);
-
+ kfree(func->tmpbuf);
kfree(func);
}
@@ -280,6 +280,16 @@ 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 50f0bc952328..2d6cc69db1fe 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 */