diff options
Diffstat (limited to 'include/asm-x86_64/tlbflush.h')
| -rw-r--r-- | include/asm-x86_64/tlbflush.h | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/include/asm-x86_64/tlbflush.h b/include/asm-x86_64/tlbflush.h index 2e811ac..505b0cf 100644 --- a/include/asm-x86_64/tlbflush.h +++ b/include/asm-x86_64/tlbflush.h @@ -22,16 +22,18 @@ */ #define __flush_tlb_global() \ do { \ - unsigned long tmpreg; \ + unsigned long tmpreg, cr4, cr4_orig; \ \ __asm__ __volatile__( \ - "movq %1, %%cr4; # turn off PGE \n" \ + "movq %%cr4, %2; # turn off PGE \n" \ + "movq %2, %1; \n" \ + "andq %3, %1; \n" \ + "movq %1, %%cr4; \n" \ "movq %%cr3, %0; # flush TLB \n" \ "movq %0, %%cr3; \n" \ "movq %2, %%cr4; # turn PGE back on \n" \ - : "=&r" (tmpreg) \ - : "r" (mmu_cr4_features & ~X86_CR4_PGE), \ - "r" (mmu_cr4_features) \ + : "=&r" (tmpreg), "=&r" (cr4), "=&r" (cr4_orig) \ + : "i" (~X86_CR4_PGE) \ : "memory"); \ } while (0) @@ -54,8 +56,9 @@ extern unsigned long pgkern_mask; * - flush_tlb_kernel_range(start, end) flushes a range of kernel pages * - flush_tlb_pgtables(mm, start, end) flushes a range of page tables * - * ..but the x86_64 has somewhat limited tlb flushing capabilities, - * and page-granular flushes are available only on i486 and up. + * x86-64 can only flush individual pages or full VMs. For a range flush + * we always do the full VM. Might be worth trying if for a small + * range a few INVLPGs in a row are a win. */ #ifndef CONFIG_SMP @@ -113,7 +116,9 @@ static inline void flush_tlb_range(struct vm_area_struct * vma, unsigned long st static inline void flush_tlb_pgtables(struct mm_struct *mm, unsigned long start, unsigned long end) { - /* x86_64 does not keep any page table caches in TLB */ + /* x86_64 does not keep any page table caches in a software TLB. + The CPUs do in their hardware TLBs, but they are handled + by the normal TLB flushing algorithms. */ } #endif /* _X8664_TLBFLUSH_H */ |
