[PATCH v2 10/11] PM / Hibernate: clean cached pages on architectures that require it
Lorenzo Pieralisi
lorenzo.pieralisi at arm.com
Wed Nov 11 03:40:39 PST 2015
Hi Pavel, Rafael,
Do you have any feedback on this patch ?
It is fundamental to this series and affects Hibernate core code so if you
have any feedback that would be much appreciated.
Thanks a lot,
Lorenzo
On Tue, Oct 27, 2015 at 05:29:19PM +0000, 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>
> ---
> 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
> @@ -31,6 +31,7 @@
> #include <linux/ktime.h>
>
> #include <asm/uaccess.h>
> +#include <asm/cacheflush.h>
> #include <asm/mmu_context.h>
> #include <asm/pgtable.h>
> #include <asm/tlbflush.h>
> @@ -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;
>
> for (n = PAGE_SIZE / sizeof(long); n; n--)
> *dst++ = *src++;
> +
> + flush_icache_range(start, start+PAGE_SIZE);
> }
>
>
> --
> 2.1.4
>
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