[PATCH V4 1/2] riscv: Fixup _PAGE_GLOBAL in _PAGE_KERNEL

guoren
2021-05-26T05:50:30Z

From: Guo Ren <guoren@linux.alibaba.com>

Kernel virtual address translation should avoid to use ASIDs or it'll
cause more TLB-miss and TLB-refill. Because the current ASID in satp
belongs to the current process, but the target kernel va TLB entry's
ASID still belongs to the previous process.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
---
arch/riscv/include/asm/pgtable.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 9469f46..346a3c6 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -134,7 +134,8 @@
| _PAGE_WRITE \
| _PAGE_PRESENT \
| _PAGE_ACCESSED \
- | _PAGE_DIRTY)
+ | _PAGE_DIRTY \
+ | _PAGE_GLOBAL)

#define PAGE_KERNEL __pgprot(_PAGE_KERNEL)
#define PAGE_KERNEL_READ __pgprot(_PAGE_KERNEL & ~_PAGE_WRITE)
--
2.7.4