Hi all,
No ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1 in this patch, I'll remove it
in V3.
The update_mmu_cache() is wrong with sfence.vma and I'll give another
patch to fixup it with ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1.
Best Regards
Guo Ren
On Mon, Jan 27, 2020 at 10:50:08PM +0800, Guo Ren wrote:
> The patch is the fixup for the commit 08f051eda33b by Andrew.
>
> For copy_to_user_page, the only call path is:
> __access_remote_vm -> copy_to_user_page -> flush_icache_user_range
>
> Seems it's ok to use flush_icache_mm instead of flush_icache_all and
> it could reduce flush_icache_all called on other harts.
>
> Add (vma->vm_flags & VM_EXEC) condition to flush icache only for
> executable vma area.
>
> ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is used in a lot of fs/block codes.
> We need it to make their pages dirty and defer sync i/dcache in
> update_mmu_cache().
>
> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
> Cc: Andrew Waterman <andrew@xxxxxxxxxx>
> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
> Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
>
> ---
> Changelog V2:
> - Add VM_EXEC condition.
> - Remove flush_icache_user_range definition.
> - define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
> ---
> arch/riscv/include/asm/cacheflush.h | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h
> index b69aecbb36d3..ae57d6ce63a9 100644
> --- a/arch/riscv/include/asm/cacheflush.h
> +++ b/arch/riscv/include/asm/cacheflush.h
> @@ -8,7 +8,7 @@
>
> #include <linux/mm.h>
>
> -#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
> +#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
>
> /*
> * The cache doesn't need to be flushed when TLB entries change when
> @@ -62,7 +62,8 @@ static inline void flush_cache_vunmap(unsigned long start, unsigned long end)
> #define copy_to_user_page(vma, page, vaddr, dst, src, len) \
> do { \
> memcpy(dst, src, len); \
> - flush_icache_user_range(vma, page, vaddr, len); \
> + if (vma->vm_flags & VM_EXEC) \
> + flush_icache_mm(vma->vm_mm, 0); \
> } while (0)
> #define copy_from_user_page(vma, page, vaddr, dst, src, len) \
> memcpy(dst, src, len)
> @@ -85,7 +86,6 @@ static inline void flush_dcache_page(struct page *page)
> * so instead we just flush the whole thing.
> */
> #define flush_icache_range(start, end) flush_icache_all()
> -#define flush_icache_user_range(vma, pg, addr, len) flush_icache_all()
>
> void dma_wbinv_range(unsigned long start, unsigned long end);
> void dma_wb_range(unsigned long start, unsigned long end);
> --
> 2.17.0
