Remove d-cache hack in ramzswap driver that was needed
to workaround a bug in ARM version of update_mmu_cache()
which caused stale data in d-cache to be transferred to
userspace. This bug was fixed by git commit:
787b2faadc4356b6c2c71feb42fb944fece9a12f
This also brings down one entry in TODO file.
Signed-off-by: Nitin Gupta <[email protected]>
---
drivers/staging/ramzswap/TODO | 1 -
drivers/staging/ramzswap/ramzswap_drv.c | 28 +++-------------------------
2 files changed, 3 insertions(+), 26 deletions(-)
diff --git a/drivers/staging/ramzswap/TODO b/drivers/staging/ramzswap/TODO
index bac40d6..8d64e28 100644
--- a/drivers/staging/ramzswap/TODO
+++ b/drivers/staging/ramzswap/TODO
@@ -1,6 +1,5 @@
TODO:
- Add support for swap notifiers
- - Remove CONFIG_ARM hack
Please send patches to Greg Kroah-Hartman <[email protected]> and
Nitin Gupta <[email protected]>
diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
index b839f05..989fac5 100644
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -222,28 +222,6 @@ out:
return ret;
}
-static void ramzswap_flush_dcache_page(struct page *page)
-{
-#ifdef CONFIG_ARM
- int flag = 0;
- /*
- * Ugly hack to get flush_dcache_page() work on ARM.
- * page_mapping(page) == NULL after clearing this swap cache flag.
- * Without clearing this flag, flush_dcache_page() will simply set
- * "PG_dcache_dirty" bit and return.
- */
- if (PageSwapCache(page)) {
- flag = 1;
- ClearPageSwapCache(page);
- }
-#endif
- flush_dcache_page(page);
-#ifdef CONFIG_ARM
- if (flag)
- SetPageSwapCache(page);
-#endif
-}
-
void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
struct ramzswap_ioctl_stats *s)
{
@@ -655,7 +633,7 @@ static int handle_zero_page(struct bio *bio)
memset(user_mem, 0, PAGE_SIZE);
kunmap_atomic(user_mem, KM_USER0);
- ramzswap_flush_dcache_page(page);
+ flush_dcache_page(page);
set_bit(BIO_UPTODATE, &bio->bi_flags);
bio_endio(bio, 0);
@@ -679,7 +657,7 @@ static int handle_uncompressed_page(struct ramzswap *rzs, struct bio *bio)
kunmap_atomic(user_mem, KM_USER0);
kunmap_atomic(cmem, KM_USER1);
- ramzswap_flush_dcache_page(page);
+ flush_dcache_page(page);
set_bit(BIO_UPTODATE, &bio->bi_flags);
bio_endio(bio, 0);
@@ -779,7 +757,7 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
goto out;
}
- ramzswap_flush_dcache_page(page);
+ flush_dcache_page(page);
set_bit(BIO_UPTODATE, &bio->bi_flags);
bio_endio(bio, 0);
On Sat, Dec 12, 2009 at 8:14 AM, Nitin Gupta <[email protected]> wrote:
> Remove d-cache hack in ramzswap driver that was needed
> to workaround a bug in ARM version of update_mmu_cache()
> which caused stale data in d-cache to be transferred to
> userspace. This bug was fixed by git commit:
> ? ? ? ?787b2faadc4356b6c2c71feb42fb944fece9a12f
> This also brings down one entry in TODO file.
>
> Signed-off-by: Nitin Gupta <[email protected]>
Acked-by: Pekka Enberg <[email protected]>
> ---
> ?drivers/staging/ramzswap/TODO ? ? ? ? ? | ? ?1 -
> ?drivers/staging/ramzswap/ramzswap_drv.c | ? 28 +++-------------------------
> ?2 files changed, 3 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/staging/ramzswap/TODO b/drivers/staging/ramzswap/TODO
> index bac40d6..8d64e28 100644
> --- a/drivers/staging/ramzswap/TODO
> +++ b/drivers/staging/ramzswap/TODO
> @@ -1,6 +1,5 @@
> ?TODO:
> ? ? ? ?- Add support for swap notifiers
> - ? ? ? - Remove CONFIG_ARM hack
>
> ?Please send patches to Greg Kroah-Hartman <[email protected]> and
> ?Nitin Gupta <[email protected]>
> diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
> index b839f05..989fac5 100644
> --- a/drivers/staging/ramzswap/ramzswap_drv.c
> +++ b/drivers/staging/ramzswap/ramzswap_drv.c
> @@ -222,28 +222,6 @@ out:
> ? ? ? ?return ret;
> ?}
>
> -static void ramzswap_flush_dcache_page(struct page *page)
> -{
> -#ifdef CONFIG_ARM
> - ? ? ? int flag = 0;
> - ? ? ? /*
> - ? ? ? ?* Ugly hack to get flush_dcache_page() work on ARM.
> - ? ? ? ?* page_mapping(page) == NULL after clearing this swap cache flag.
> - ? ? ? ?* Without clearing this flag, flush_dcache_page() will simply set
> - ? ? ? ?* "PG_dcache_dirty" bit and return.
> - ? ? ? ?*/
> - ? ? ? if (PageSwapCache(page)) {
> - ? ? ? ? ? ? ? flag = 1;
> - ? ? ? ? ? ? ? ClearPageSwapCache(page);
> - ? ? ? }
> -#endif
> - ? ? ? flush_dcache_page(page);
> -#ifdef CONFIG_ARM
> - ? ? ? if (flag)
> - ? ? ? ? ? ? ? SetPageSwapCache(page);
> -#endif
> -}
> -
> ?void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
> ? ? ? ? ? ? ? ? ? ? ? ?struct ramzswap_ioctl_stats *s)
> ?{
> @@ -655,7 +633,7 @@ static int handle_zero_page(struct bio *bio)
> ? ? ? ?memset(user_mem, 0, PAGE_SIZE);
> ? ? ? ?kunmap_atomic(user_mem, KM_USER0);
>
> - ? ? ? ramzswap_flush_dcache_page(page);
> + ? ? ? flush_dcache_page(page);
>
> ? ? ? ?set_bit(BIO_UPTODATE, &bio->bi_flags);
> ? ? ? ?bio_endio(bio, 0);
> @@ -679,7 +657,7 @@ static int handle_uncompressed_page(struct ramzswap *rzs, struct bio *bio)
> ? ? ? ?kunmap_atomic(user_mem, KM_USER0);
> ? ? ? ?kunmap_atomic(cmem, KM_USER1);
>
> - ? ? ? ramzswap_flush_dcache_page(page);
> + ? ? ? flush_dcache_page(page);
>
> ? ? ? ?set_bit(BIO_UPTODATE, &bio->bi_flags);
> ? ? ? ?bio_endio(bio, 0);
> @@ -779,7 +757,7 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
> ? ? ? ? ? ? ? ?goto out;
> ? ? ? ?}
>
> - ? ? ? ramzswap_flush_dcache_page(page);
> + ? ? ? flush_dcache_page(page);
>
> ? ? ? ?set_bit(BIO_UPTODATE, &bio->bi_flags);
> ? ? ? ?bio_endio(bio, 0);
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at ?http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at ?http://www.tux.org/lkml/
>
On 12/12/2009 01:11 PM, Pekka Enberg wrote:
> On Sat, Dec 12, 2009 at 8:14 AM, Nitin Gupta <[email protected]> wrote:
>> Remove d-cache hack in ramzswap driver that was needed
>> to workaround a bug in ARM version of update_mmu_cache()
>> which caused stale data in d-cache to be transferred to
>> userspace. This bug was fixed by git commit:
>> 787b2faadc4356b6c2c71feb42fb944fece9a12f
>> This also brings down one entry in TODO file.
>>
>> Signed-off-by: Nitin Gupta <[email protected]>
>
> Acked-by: Pekka Enberg <[email protected]>
Thanks for review Pekka.
Now wondering when this patch will be committed to mainline.
Nitin
>
>> ---
>> drivers/staging/ramzswap/TODO | 1 -
>> drivers/staging/ramzswap/ramzswap_drv.c | 28 +++-------------------------
>> 2 files changed, 3 insertions(+), 26 deletions(-)
>>
>> diff --git a/drivers/staging/ramzswap/TODO b/drivers/staging/ramzswap/TODO
>> index bac40d6..8d64e28 100644
>> --- a/drivers/staging/ramzswap/TODO
>> +++ b/drivers/staging/ramzswap/TODO
>> @@ -1,6 +1,5 @@
>> TODO:
>> - Add support for swap notifiers
>> - - Remove CONFIG_ARM hack
>>
>> Please send patches to Greg Kroah-Hartman <[email protected]> and
>> Nitin Gupta <[email protected]>
>> diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c
>> index b839f05..989fac5 100644
>> --- a/drivers/staging/ramzswap/ramzswap_drv.c
>> +++ b/drivers/staging/ramzswap/ramzswap_drv.c
>> @@ -222,28 +222,6 @@ out:
>> return ret;
>> }
>>
>> -static void ramzswap_flush_dcache_page(struct page *page)
>> -{
>> -#ifdef CONFIG_ARM
>> - int flag = 0;
>> - /*
>> - * Ugly hack to get flush_dcache_page() work on ARM.
>> - * page_mapping(page) == NULL after clearing this swap cache flag.
>> - * Without clearing this flag, flush_dcache_page() will simply set
>> - * "PG_dcache_dirty" bit and return.
>> - */
>> - if (PageSwapCache(page)) {
>> - flag = 1;
>> - ClearPageSwapCache(page);
>> - }
>> -#endif
>> - flush_dcache_page(page);
>> -#ifdef CONFIG_ARM
>> - if (flag)
>> - SetPageSwapCache(page);
>> -#endif
>> -}
>> -
>> void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
>> struct ramzswap_ioctl_stats *s)
>> {
>> @@ -655,7 +633,7 @@ static int handle_zero_page(struct bio *bio)
>> memset(user_mem, 0, PAGE_SIZE);
>> kunmap_atomic(user_mem, KM_USER0);
>>
>> - ramzswap_flush_dcache_page(page);
>> + flush_dcache_page(page);
>>
>> set_bit(BIO_UPTODATE, &bio->bi_flags);
>> bio_endio(bio, 0);
>> @@ -679,7 +657,7 @@ static int handle_uncompressed_page(struct ramzswap *rzs, struct bio *bio)
>> kunmap_atomic(user_mem, KM_USER0);
>> kunmap_atomic(cmem, KM_USER1);
>>
>> - ramzswap_flush_dcache_page(page);
>> + flush_dcache_page(page);
>>
>> set_bit(BIO_UPTODATE, &bio->bi_flags);
>> bio_endio(bio, 0);
>> @@ -779,7 +757,7 @@ static int ramzswap_read(struct ramzswap *rzs, struct bio *bio)
>> goto out;
>> }
>>
>> - ramzswap_flush_dcache_page(page);
>> + flush_dcache_page(page);
>>
>> set_bit(BIO_UPTODATE, &bio->bi_flags);
>> bio_endio(bio, 0);
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/
>>
>
On Sun, Dec 13, 2009 at 3:21 AM, Nitin Gupta <[email protected]> wrote:
> On 12/12/2009 01:11 PM, Pekka Enberg wrote:
>> On Sat, Dec 12, 2009 at 8:14 AM, Nitin Gupta <[email protected]> wrote:
>>> Remove d-cache hack in ramzswap driver that was needed
>>> to workaround a bug in ARM version of update_mmu_cache()
>>> which caused stale data in d-cache to be transferred to
>>> userspace. This bug was fixed by git commit:
>>> ? ? ? ?787b2faadc4356b6c2c71feb42fb944fece9a12f
>>> This also brings down one entry in TODO file.
>>>
>>> Signed-off-by: Nitin Gupta <[email protected]>
>>
>> Acked-by: Pekka Enberg <[email protected]>
>
> Thanks for review Pekka.
> Now wondering when this patch will be committed to mainline.
I don't see any reason why this shouldn't go into .33 but that's
really up to Greg.
Pekka
On Sun, Dec 13, 2009 at 10:36:26PM +0200, Pekka Enberg wrote:
> On Sun, Dec 13, 2009 at 3:21 AM, Nitin Gupta <[email protected]> wrote:
> > On 12/12/2009 01:11 PM, Pekka Enberg wrote:
> >> On Sat, Dec 12, 2009 at 8:14 AM, Nitin Gupta <[email protected]> wrote:
> >>> Remove d-cache hack in ramzswap driver that was needed
> >>> to workaround a bug in ARM version of update_mmu_cache()
> >>> which caused stale data in d-cache to be transferred to
> >>> userspace. This bug was fixed by git commit:
> >>> ? ? ? ?787b2faadc4356b6c2c71feb42fb944fece9a12f
> >>> This also brings down one entry in TODO file.
> >>>
> >>> Signed-off-by: Nitin Gupta <[email protected]>
> >>
> >> Acked-by: Pekka Enberg <[email protected]>
> >
> > Thanks for review Pekka.
> > Now wondering when this patch will be committed to mainline.
>
> I don't see any reason why this shouldn't go into .33 but that's
> really up to Greg.
It will end up there, thanks, I will queue it up in a few days to go
there.
thanks,
greg k-h
This is a note to let you know that I've just added the patch titled
Subject: Staging: ramzswap: remove ARM specific d-cache hack
to my gregkh-2.6 tree. Its filename is
staging-ramzswap-remove-arm-specific-d-cache-hack.patch
This tree can be found at
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/
>From [email protected] Fri Dec 18 10:22:00 2009
From: Nitin Gupta <[email protected]>
Date: Sat, 12 Dec 2009 11:44:46 +0530
Subject: Staging: ramzswap: remove ARM specific d-cache hack
To: Greg KH <[email protected]>
Cc: Andrew Morton <[email protected]>, linux-kernel <[email protected]>
Message-ID: <[email protected]>
Remove d-cache hack in ramzswap driver that was needed
to workaround a bug in ARM version of update_mmu_cache()
which caused stale data in d-cache to be transferred to
userspace. This bug was fixed by git commit:
787b2faadc4356b6c2c71feb42fb944fece9a12f
This also brings down one entry in TODO file.
Signed-off-by: Nitin Gupta <[email protected]>
Acked-by: Pekka Enberg <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/staging/ramzswap/TODO | 1 -
drivers/staging/ramzswap/ramzswap_drv.c | 28 +++-------------------------
2 files changed, 3 insertions(+), 26 deletions(-)
--- a/drivers/staging/ramzswap/ramzswap_drv.c
+++ b/drivers/staging/ramzswap/ramzswap_drv.c
@@ -222,28 +222,6 @@ out:
return ret;
}
-static void ramzswap_flush_dcache_page(struct page *page)
-{
-#ifdef CONFIG_ARM
- int flag = 0;
- /*
- * Ugly hack to get flush_dcache_page() work on ARM.
- * page_mapping(page) == NULL after clearing this swap cache flag.
- * Without clearing this flag, flush_dcache_page() will simply set
- * "PG_dcache_dirty" bit and return.
- */
- if (PageSwapCache(page)) {
- flag = 1;
- ClearPageSwapCache(page);
- }
-#endif
- flush_dcache_page(page);
-#ifdef CONFIG_ARM
- if (flag)
- SetPageSwapCache(page);
-#endif
-}
-
void ramzswap_ioctl_get_stats(struct ramzswap *rzs,
struct ramzswap_ioctl_stats *s)
{
@@ -655,7 +633,7 @@ static int handle_zero_page(struct bio *
memset(user_mem, 0, PAGE_SIZE);
kunmap_atomic(user_mem, KM_USER0);
- ramzswap_flush_dcache_page(page);
+ flush_dcache_page(page);
set_bit(BIO_UPTODATE, &bio->bi_flags);
bio_endio(bio, 0);
@@ -679,7 +657,7 @@ static int handle_uncompressed_page(stru
kunmap_atomic(user_mem, KM_USER0);
kunmap_atomic(cmem, KM_USER1);
- ramzswap_flush_dcache_page(page);
+ flush_dcache_page(page);
set_bit(BIO_UPTODATE, &bio->bi_flags);
bio_endio(bio, 0);
@@ -779,7 +757,7 @@ static int ramzswap_read(struct ramzswap
goto out;
}
- ramzswap_flush_dcache_page(page);
+ flush_dcache_page(page);
set_bit(BIO_UPTODATE, &bio->bi_flags);
bio_endio(bio, 0);
--- a/drivers/staging/ramzswap/TODO
+++ b/drivers/staging/ramzswap/TODO
@@ -1,6 +1,5 @@
TODO:
- Add support for swap notifiers
- - Remove CONFIG_ARM hack
Please send patches to Greg Kroah-Hartman <[email protected]> and
Nitin Gupta <[email protected]>