riscv: Use global mappings for kernel pages

We map kernel pages into all addresses spages, so they can be marked as
global.  This allows hardware to avoid flushing the kernel mappings when
moving between address spaces.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[Palmer: commit text]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index bde8ce3..c103f0a 100644 (file)
--- 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)