[3.13.y.z extended stable] Patch "crypto: ux500 - make interrupt mode plausible" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

crypto: ux500 - make interrupt mode plausible

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree
which can be found at:

http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.7.

If you, or anyone else, feels it should not be added to this tree, please
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From da0a425f527432abe5d2a6428bb47f96d596f376 Mon Sep 17 00:00:00 2001

From: Arnd Bergmann <***@arndb.de>
Date: Thu, 26 Jun 2014 13:43:02 +0200
Subject: crypto: ux500 - make interrupt mode plausible

commit e1f8859ee265fc89bd21b4dca79e8e983a044892 upstream.

The interrupt handler in the ux500 crypto driver has an obviously
incorrect way to access the data buffer, which for a while has
caused this build warning:

../ux500/cryp/cryp_core.c: In function 'cryp_interrupt_handler':
../ux500/cryp/cryp_core.c:234:5: warning: passing argument 1 of '__fswab32' makes integer from pointer without a cast [enabled by default]
writel_relaxed(ctx->indata,
^
In file included from ../include/linux/swab.h:4:0,
from ../include/uapi/linux/byteorder/big_endian.h:12,
from ../include/linux/byteorder/big_endian.h:4,
from ../arch/arm/include/uapi/asm/byteorder.h:19,
from ../include/asm-generic/bitops/le.h:5,
from ../arch/arm/include/asm/bitops.h:340,
from ../include/linux/bitops.h:33,
from ../include/linux/kernel.h:10,
from ../include/linux/clk.h:16,
from ../drivers/crypto/ux500/cryp/cryp_core.c:12:
../include/uapi/linux/swab.h:57:119: note: expected '__u32' but argument is of type 'const u8 *'
static inline __attribute_const__ __u32 __fswab32(__u32 val)

There are at least two, possibly three problems here:
a) when writing into the FIFO, we copy the pointer rather than the
actual data we want to give to the hardware
b) the data pointer is an array of 8-bit values, while the FIFO
is 32-bit wide, so both the read and write access fail to do
a proper type conversion
c) This seems incorrect for big-endian kernels, on which we need to
byte-swap any register access, but not normally FIFO accesses,
at least the DMA case doesn't do it either.

This converts the bogus loop to use the same readsl/writesl pair
that we use for the two other modes (DMA and polling). This is
more efficient and consistent, and probably correct for endianess.

The bug has existed since the driver was first merged, and was
probably never detected because nobody tried to use interrupt mode.
It might make sense to backport this fix to stable kernels, depending
on how the crypto maintainers feel about that.

Signed-off-by: Arnd Bergmann <***@arndb.de>
Cc: linux-***@vger.kernel.org
Cc: Fabio Baltieri <***@linaro.org>
Cc: Linus Walleij <***@linaro.org>
Cc: Herbert Xu <***@gondor.apana.org.au>
Cc: "David S. Miller" <***@davemloft.net>
Signed-off-by: Herbert Xu <***@gondor.apana.org.au>
Signed-off-by: Kamal Mostafa <***@canonical.com>
---
drivers/crypto/ux500/cryp/cryp_core.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/crypto/ux500/cryp/cryp_core.c b/drivers/crypto/ux500/cryp/cryp_core.c
index a999f53..92105f3 100644
--- a/drivers/crypto/ux500/cryp/cryp_core.c
+++ b/drivers/crypto/ux500/cryp/cryp_core.c
@@ -190,7 +190,7 @@ static void add_session_id(struct cryp_ctx *ctx)
static irqreturn_t cryp_interrupt_handler(int irq, void *param)
{
struct cryp_ctx *ctx;
- int i;
+ int count;
struct cryp_device_data *device_data;

if (param == NULL) {
@@ -215,12 +215,11 @@ static irqreturn_t cryp_interrupt_handler(int irq, void *param)
if (cryp_pending_irq_src(device_data,
CRYP_IRQ_SRC_OUTPUT_FIFO)) {
if (ctx->outlen / ctx->blocksize > 0) {
- for (i = 0; i < ctx->blocksize / 4; i++) {
- *(ctx->outdata) = readl_relaxed(
- &device_data->base->dout);
- ctx->outdata += 4;
- ctx->outlen -= 4;
- }
+ count = ctx->blocksize / 4;
+
+ readsl(&device_data->base->dout, ctx->outdata, count);
+ ctx->outdata += count;
+ ctx->outlen -= count;

if (ctx->outlen == 0) {
cryp_disable_irq_src(device_data,
@@ -230,12 +229,12 @@ static irqreturn_t cryp_interrupt_handler(int irq, void *param)
} else if (cryp_pending_irq_src(device_data,
CRYP_IRQ_SRC_INPUT_FIFO)) {
if (ctx->datalen / ctx->blocksize > 0) {
- for (i = 0 ; i < ctx->blocksize / 4; i++) {
- writel_relaxed(ctx->indata,
- &device_data->base->din);
- ctx->indata += 4;
- ctx->datalen -= 4;
- }
+ count = ctx->blocksize / 4;
+
+ writesl(&device_data->base->din, ctx->indata, count);
+
+ ctx->indata += count;
+ ctx->datalen -= count;

if (ctx->datalen == 0)
cryp_disable_irq_src(device_data,
--
1.9.1