[U-Boot] [U-Boot PATCH v2 01/10] sf: allocate cache aligned buffers to copy from flash

[Jagan Teki]

On 14 August 2015 at 00:08, Simon Glass <sjg at chromium.org> wrote:
> Hi,
>
> On 13 August 2015 at 12:23, Tom Rini <trini at konsulko.com> wrote:
>> On Thu, Aug 13, 2015 at 11:38:00PM +0530, Jagan Teki wrote:
>>> On 13 August 2015 at 23:24, Tom Rini <trini at konsulko.com> wrote:
>>> > On Thu, Aug 13, 2015 at 11:09:03PM +0530, Jagan Teki wrote:
>>> >> Hi Simon,
>>> >>
>>> >> On 30 July 2015 at 11:04, Vignesh R <vigneshr at ti.com> wrote:
>>> >> > From: Ravi Babu <ravibabu at ti.com>
>>> >> >
>>> >> > Use memalign() with ARCH_DMA_MINALIGN to allocate read buffers.
>>> >> > This is required because, flash drivers may use DMA for read operations
>>> >> > and may have to invalidate the buffer before read.
>>> >> >
>>> >> > Signed-off-by: Ravi Babu <ravibabu at ti.com>
>>> >> > Signed-off-by: Vignesh R <vigneshr at ti.com>
>>> >> > ---
>>> >> >  common/cmd_sf.c | 6 +++---
>>> >> >  1 file changed, 3 insertions(+), 3 deletions(-)
>>> >> >
>>> >> > diff --git a/common/cmd_sf.c b/common/cmd_sf.c
>>> >> > index 3746e0d9644f..ac7f5dfb8181 100644
>>> >> > --- a/common/cmd_sf.c
>>> >> > +++ b/common/cmd_sf.c
>>> >> > @@ -223,7 +223,7 @@ static int spi_flash_update(struct spi_flash *flash, u32 offset,
>>> >> >
>>> >> >         if (end - buf >= 200)
>>> >> >                 scale = (end - buf) / 100;
>>> >> > -       cmp_buf = malloc(flash->sector_size);
>>> >> > +       cmp_buf = memalign(ARCH_DMA_MINALIGN, flash->sector_size);
>>> >>
>>> >> I always have a confusion like align macro is never used on code
>>> >> memalign_simple()
>>> >> Was it a typo missing or some thing?
>>> >
>>> > Sorry?  We always call memalign() rather than memalign_simple().
>>>
>>> memalign() is calling memalign_simple() except __libc_memalign
>>>
>>> Am I missing something here, because ARCH_DMA_MINALIGN is never used
>>> on memalign_simple()
>>
>> Yes, unless I'm missing something now, memalign_simple() is only used on
>> CONFIG_SYS_MALLOC_SIMPLE which has some very specific use cases.  We
>> otherwise use memalign from common/dlmalloc.c..
>
> It looks like memalign_simple()  should use
>
>         addr = ALIGN(gd->malloc_base + gd->malloc_ptr, align);
>
> instead of:
>
>         addr = ALIGN(gd->malloc_base + gd->malloc_ptr, bytes);

I think we can do the requested bytes as well like

new_ptr = ALIGN(addr + bytes, align);

thanks!
-- 
Jagan | openedev.