diff options
Diffstat (limited to 'arch/x86/mm/pageattr.c')
| -rw-r--r-- | arch/x86/mm/pageattr.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 7be47d1a97e..9c4294986af 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -482,6 +482,13 @@ static int split_large_page(pte_t *kpte, unsigned long address) pbase = (pte_t *)page_address(base); paravirt_alloc_pte(&init_mm, page_to_pfn(base)); ref_prot = pte_pgprot(pte_clrhuge(*kpte)); + /* + * If we ever want to utilize the PAT bit, we need to + * update this function to make sure it's converted from + * bit 12 to bit 7 when we cross from the 2MB level to + * the 4K level: + */ + WARN_ON_ONCE(pgprot_val(ref_prot) & _PAGE_PAT_LARGE); #ifdef CONFIG_X86_64 if (level == PG_LEVEL_1G) { @@ -515,6 +522,17 @@ static int split_large_page(pte_t *kpte, unsigned long address) * primary protection behavior: */ __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE))); + + /* + * Intel Atom errata AAH41 workaround. + * + * The real fix should be in hw or in a microcode update, but + * we also probabilistically try to reduce the window of having + * a large TLB mixed with 4K TLBs while instruction fetches are + * going on. + */ + __flush_tlb_all(); + base = NULL; out_unlock: |