Re: [PATCH] ramzswap: remove ARM specific d-cache hack

[Pekka Enberg <penberg@cs.helsinki.fi>]

On Sat, Dec 12, 2009 at 8:14 AM, Nitin Gupta <ngupta@vflare.org> 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 <ngupta@vflare.org>

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>

> ---
>  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 <greg@kroah.com> and
>  Nitin Gupta <ngupta@vflare.org>
> 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);
> --
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