Re: [PATCH] riscv: Use flush_icache_mm for flush_icache_user_range

From: Palmer Dabbelt
Date: Thu Jan 30 2020 - 12:40:56 EST


On Fri, 24 Jan 2020 16:18:10 GMT (+0000), guoren@xxxxxxxxxxxxxxxxx wrote:
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.

I think the patch is the fixup for the commit 08f051eda33b.

Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Cc: Andrew Waterman <andrew@xxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxx>
---
arch/riscv/include/asm/cacheflush.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h
index b69aecbb36d3..26589623fd57 100644
--- a/arch/riscv/include/asm/cacheflush.h
+++ b/arch/riscv/include/asm/cacheflush.h
@@ -85,7 +85,7 @@ 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()
+#define flush_icache_user_range(vma, pg, addr, len) flush_icache_mm(vma->vm_mm, 0)

void dma_wbinv_range(unsigned long start, unsigned long end);
void dma_wb_range(unsigned long start, unsigned long end);

Reviewed-by: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>

I've added this to for-next with some minor modifications as
4d99abce8ce80e866020ffa5b2bd790269235f37. It missed the PR I'm sending
now-ish, but I'll include it as part of the next one even if it's during an
early RC.

Thanks!