[U-Boot] [PATCH V2] nand: fix buffer alignment in new verification feature

[U-Boot] [PATCH V2] nand: fix buffer alignment in new verification feature

[Stephen Warren]

From: Stephen Warren <swarren@nvidia.com>

On systems with caches enabled, NAND I/O may need to flush/invalidate
the cache during read/write operations. For this to work correctly, all
buffers must be cache-aligned. Fix nand_verify*() to allocate aligned
buffers.

This prevents cache alignment warnings from being spewed when using
U-Boot to write an updated version of itself to flash on NVIDIA Tegra
Seaboard (after perturbation of stack/data layout in current
u-boot-dm/next branch).

I have validatd (executed) nand_verify(), but I don't think I've executed
nand_verify_page_oob(); testing of that would be useful.

Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Scott Wood <scottwood@freescale.com>
Fixes: 59b5a2ad83df ("nand: Add verification functions")
Signed-off-by: Stephen Warren <swarren@nvidia.com>
---
v2: Use memalign() rather than ALLOC_CACHE_ALIGN_BUFFER() so that the
buffer is allocated from the heap not on the stack, to reduce stack
usage.
---
 drivers/mtd/nand/nand_util.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
index 12dd26a33fac..ee2c24df3b85 100644
--- a/drivers/mtd/nand/nand_util.c
+++ b/drivers/mtd/nand/nand_util.c
@@ -483,7 +483,7 @@ int nand_verify_page_oob(nand_info_t *nand, struct mtd_oob_ops *ops, loff_t ofs)
 
 	memcpy(&vops, ops, sizeof(vops));
 
-	vops.datbuf = malloc(verlen);
+	vops.datbuf = memalign(ARCH_DMA_MINALIGN, verlen);
 
 	if (!vops.datbuf)
 		return -ENOMEM;
@@ -520,7 +520,7 @@ int nand_verify(nand_info_t *nand, loff_t ofs, size_t len, u_char *buf)
 	int rval = 0;
 	size_t verofs;
 	size_t verlen = nand->writesize;
-	uint8_t *verbuf = malloc(verlen);
+	uint8_t *verbuf = memalign(ARCH_DMA_MINALIGN, verlen);
 
 	if (!verbuf)
 		return -ENOMEM;
-- 
1.9.1

[U-Boot] [PATCH V2] nand: fix buffer alignment in new verification feature

[Simon Glass]

On 14 April 2015 at 08:59, Stephen Warren <swarren@wwwdotorg.org> wrote:
> From: Stephen Warren <swarren@nvidia.com>
>
> On systems with caches enabled, NAND I/O may need to flush/invalidate
> the cache during read/write operations. For this to work correctly, all
> buffers must be cache-aligned. Fix nand_verify*() to allocate aligned
> buffers.
>
> This prevents cache alignment warnings from being spewed when using
> U-Boot to write an updated version of itself to flash on NVIDIA Tegra
> Seaboard (after perturbation of stack/data layout in current
> u-boot-dm/next branch).
>
> I have validatd (executed) nand_verify(), but I don't think I've executed
> nand_verify_page_oob(); testing of that would be useful.
>
> Cc: Peter Tyser <ptyser@xes-inc.com>
> Cc: Heiko Schocher <hs@denx.de>
> Cc: Scott Wood <scottwood@freescale.com>
> Fixes: 59b5a2ad83df ("nand: Add verification functions")
> Signed-off-by: Stephen Warren <swarren@nvidia.com>

Reviewed-by: Simon Glass <sjg@chromium.org>

[U-Boot] [PATCH V2] nand: fix buffer alignment in new verification feature

[Stephen Warren]

On 04/14/2015 08:59 AM, Stephen Warren wrote:
> From: Stephen Warren <swarren@nvidia.com>
>
> On systems with caches enabled, NAND I/O may need to flush/invalidate
> the cache during read/write operations. For this to work correctly, all
> buffers must be cache-aligned. Fix nand_verify*() to allocate aligned
> buffers.
>
> This prevents cache alignment warnings from being spewed when using
> U-Boot to write an updated version of itself to flash on NVIDIA Tegra
> Seaboard (after perturbation of stack/data layout in current
> u-boot-dm/next branch).
>
> I have validatd (executed) nand_verify(), but I don't think I've executed
> nand_verify_page_oob(); testing of that would be useful.
>
> Cc: Peter Tyser <ptyser@xes-inc.com>
> Cc: Heiko Schocher <hs@denx.de>
> Cc: Scott Wood <scottwood@freescale.com>
> Fixes: 59b5a2ad83df ("nand: Add verification functions")
> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> ---
> v2: Use memalign() rather than ALLOC_CACHE_ALIGN_BUFFER() so that the
> buffer is allocated from the heap not on the stack, to reduce stack
> usage.

Scott, does this version look good?

[U-Boot] [PATCH V2] nand: fix buffer alignment in new verification feature

[Scott Wood]

On Wed, 2015-04-29 at 15:20 -0600, Stephen Warren wrote:
> On 04/14/2015 08:59 AM, Stephen Warren wrote:
> > From: Stephen Warren <swarren@nvidia.com>
> >
> > On systems with caches enabled, NAND I/O may need to flush/invalidate
> > the cache during read/write operations. For this to work correctly, all
> > buffers must be cache-aligned. Fix nand_verify*() to allocate aligned
> > buffers.
> >
> > This prevents cache alignment warnings from being spewed when using
> > U-Boot to write an updated version of itself to flash on NVIDIA Tegra
> > Seaboard (after perturbation of stack/data layout in current
> > u-boot-dm/next branch).
> >
> > I have validatd (executed) nand_verify(), but I don't think I've executed
> > nand_verify_page_oob(); testing of that would be useful.
> >
> > Cc: Peter Tyser <ptyser@xes-inc.com>
> > Cc: Heiko Schocher <hs@denx.de>
> > Cc: Scott Wood <scottwood@freescale.com>
> > Fixes: 59b5a2ad83df ("nand: Add verification functions")
> > Signed-off-by: Stephen Warren <swarren@nvidia.com>
> > ---
> > v2: Use memalign() rather than ALLOC_CACHE_ALIGN_BUFFER() so that the
> > buffer is allocated from the heap not on the stack, to reduce stack
> > usage.
> 
> Scott, does this version look good?

Yes.  I'll apply it the next time I look at U-Boot patches, or if you
want it faster:

Acked-by: Scott Wood <scottwood@freescale.com>

-Scott