It is not necessary to flush tlb page on all CPUs if suitable PTE
entry exists already during page fault handling, just updating
TLB is fine.

Here redefine flush_tlb_fix_spurious_fault as empty on MIPS system.

Change in v2:
- split flush_tlb_fix_spurious_fault and tlb update into two patches
- comments typo modification
- separate tlb update and add pte readable privilege into two patches
Change in V3:
- add detailed changelog, modify typo issue in patch V2

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 arch/mips/include/asm/pgtable.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 9b01d2d..0d625c2 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h

@@ -478,6 +478,8 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
 	return __pgprot(prot);
 }
 
+#define flush_tlb_fix_spurious_fault(vma, address) do { } while (0)
+
 /*
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.

-- 
1.8.3.1