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.
ÂÂ Need empty line here.
V6:
- Add update_mmu_tlb function as empty on all platform except mips
ÂÂ system, we use this function to update local tlb for page fault
ÂÂ smp-race handling
V5:
- define update_mmu_cache function specified on MIPS platform, and
ÂÂ add page fault smp-race stats info
V4:
- add pte_sw_mkyoung function to implement readable privilege, and
 this function is only in effect on MIPS system.
- add page valid bit judgement in function pte_modify
V3:
- add detailed changelog, modify typo issue in patch V2
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
 It was a bad idea to keep the version change log in the 1st patch only,
we have either cover letter for that, or all the individual patches...
Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>[...]