lkml.org 
[lkml]   [2017]   [Dec]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/3] mtd: spi-nor: add optional DMA-safe bounce buffer for data transfer
From
Date
Hi Vignesh

Le 26/12/2017 à 14:42, Vignesh R a écrit :
> Hi Cyrille,
>
> Thanks for doing this series! One comment below.
>
> On 24-Dec-17 10:06 AM, Cyrille Pitchen wrote:
> [...]
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index 8bafd462f0ae..59f9fbd45234 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -14,8 +14,10 @@
>> #include <linux/errno.h>
>> #include <linux/module.h>
>> #include <linux/device.h>
>> +#include <linux/highmem.h>
>> #include <linux/mutex.h>
>> #include <linux/math64.h>
>> +#include <linux/mm.h>
>> #include <linux/sizes.h>
>> #include <linux/slab.h>
>>
>> @@ -1232,6 +1234,56 @@ static const struct flash_info spi_nor_ids[] = {
>> { },
>> };
>>
>> +static bool spi_nor_is_dma_safe(const void *buf)
>> +{
>> + if (is_vmalloc_addr(buf))
>> + return false;
>> +
>> +#ifdef CONFIG_HIGHMEM
>> + if ((unsigned long)buf >= PKMAP_BASE &&
>> + (unsigned long)buf < (PKMAP_BASE + (LAST_PKMAP * PAGE_SIZE)))
>> + return false;
>> +#endif
>> +
>> + return true;
>> +}
>> +
>
> Better way would be to use virt_addr_valid():
> static bool spi_nor_is_dma_safe(const void *buf)
> {
> return virt_addr_valid(buf);
> }
>
> Regards
> Vignesh
>

Thanks for the advice :)

https://patchwork.kernel.org/patch/9768341/
Maybe I could check both virt_addr_valid() and object_is_on_stack() too ?

Best regards,

Cyrille

\
 
 \ /
  Last update: 2017-12-26 14:59    [W:0.139 / U:5.840 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site