[U-Boot] [PATCH v2 1/6] usb:gadget:ums: Replace malloc calls with memalign to fix cache buffer alignment

[Marek Vasut]

On Wednesday, February 05, 2014 at 10:10:41 AM, Lukasz Majewski wrote:
> Calls to malloc() have been replaced by memalign. It now provides proper
> buffer alignment.
> 
> Signed-off-by: Lukasz Majewski <l.majewski at samsung.com>
> Cc: Marek Vasut <marex at denx.de>
> 
> ---
> Changes for v2:
> - Remove Change-Id.
> ---
>  drivers/usb/gadget/f_mass_storage.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/gadget/f_mass_storage.c
> b/drivers/usb/gadget/f_mass_storage.c index b1fe8bd..f896169 100644
> --- a/drivers/usb/gadget/f_mass_storage.c
> +++ b/drivers/usb/gadget/f_mass_storage.c
> @@ -2515,7 +2515,7 @@ static struct fsg_common *fsg_common_init(struct
> fsg_common *common, buffhds_first_it:
>  		bh->inreq_busy = 0;
>  		bh->outreq_busy = 0;
> -		bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
> +		bh->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, FSG_BUFLEN);
>  		if (unlikely(!bh->buf)) {
>  			rc = -ENOMEM;
>  			goto error_release;
> @@ -2622,7 +2622,7 @@ usb_copy_descriptors(struct usb_descriptor_header
> **src) bytes += (*tmp)->bLength;
>  	bytes += (n_desc + 1) * sizeof(*tmp);
> 
> -	mem = kmalloc(bytes, GFP_KERNEL);
> +	mem = memalign(CONFIG_SYS_CACHELINE_SIZE, bytes);

I wonder, does this align the begining of the buffer as well or only the size? 
Can we rely on the fact the begining is also cacheline-aligned ?

>  	if (!mem)
>  		return NULL;

Best regards,
Marek Vasut