[PATCH v2 10/11] PM / Hibernate: clean cached pages on architectures that require it
Pavel Machek
pavel at ucw.cz
Sat Nov 14 12:26:24 PST 2015
On Tue 2015-10-27 17:29:19, James Morse wrote:
> Some architectures require code written to memory as if it were data to be
> 'cleaned' from any data caches so that the processor can fetch them as new
> instructions.
>
> During resume from hibernate, the snapshot code copies some pages directly,
> meaning these architectures do not get a chance to perform their cache
> maintenance. Add a call to flush_icache_range(), which is provided by
> architectures that require it, to perform the maintenance.
>
> This mirrors the kernel's behaviour when loading kernel modules and when
> mapping executable pages to user space.
>
> Signed-off-by: James Morse <james.morse at arm.com>
Looks reasonable.
Acked-by: Pavel Machek <pavel at ucw.cz>
> ---
> kernel/power/snapshot.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
> index 5235dd4e1e2f..139fc449ad75 100644
> --- a/kernel/power/snapshot.c
> +++ b/kernel/power/snapshot.c
> @@ -1196,9 +1197,12 @@ static unsigned int count_data_pages(void)
> static inline void do_copy_page(long *dst, long *src)
> {
> int n;
> + unsigned long __maybe_unused start = (unsigned long)dst;
Why the "maybe unused"?
> for (n = PAGE_SIZE / sizeof(long); n; n--)
> *dst++ = *src++;
> +
> + flush_icache_range(start, start+PAGE_SIZE);
> }
Pavel
--
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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