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author | Chris Metcalf <cmetcalf@tilera.com> | 2013-08-12 23:08:09 +0400 |
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committer | Chris Metcalf <cmetcalf@tilera.com> | 2013-09-03 22:52:13 +0400 |
commit | 640710a33b54de8d90ae140ef633ed0feba76a75 (patch) | |
tree | c58e0f7b36fef258674ddf9d5425608d3b5a430e /arch/tile/mm/pgtable.c | |
parent | 49cf78ef7bb34833496d59b6dfe84ae51b1ab097 (diff) | |
download | linux-640710a33b54de8d90ae140ef633ed0feba76a75.tar.xz |
tile: add virt_to_kpte() API and clean up and document behavior
We use virt_to_pte(NULL, va) a lot, which isn't very obvious.
I added virt_to_kpte(va) as a more obvious wrapper function,
that also validates the va as being a kernel adddress.
And, I fixed the semantics of virt_to_pte() so that we handle
the pud and pmd the same way, and we now document the fact that
we handle the final pte level differently.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Diffstat (limited to 'arch/tile/mm/pgtable.c')
-rw-r--r-- | arch/tile/mm/pgtable.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/arch/tile/mm/pgtable.c b/arch/tile/mm/pgtable.c index 300443389671..2deaddf3e01f 100644 --- a/arch/tile/mm/pgtable.c +++ b/arch/tile/mm/pgtable.c @@ -325,6 +325,17 @@ void ptep_set_wrprotect(struct mm_struct *mm, #endif +/* + * Return a pointer to the PTE that corresponds to the given + * address in the given page table. A NULL page table just uses + * the standard kernel page table; the preferred API in this case + * is virt_to_kpte(). + * + * The returned pointer can point to a huge page in other levels + * of the page table than the bottom, if the huge page is present + * in the page table. For bottom-level PTEs, the returned pointer + * can point to a PTE that is either present or not. + */ pte_t *virt_to_pte(struct mm_struct* mm, unsigned long addr) { pgd_t *pgd; @@ -341,14 +352,21 @@ pte_t *virt_to_pte(struct mm_struct* mm, unsigned long addr) if (pud_huge_page(*pud)) return (pte_t *)pud; pmd = pmd_offset(pud, addr); - if (pmd_huge_page(*pmd)) - return (pte_t *)pmd; if (!pmd_present(*pmd)) return NULL; + if (pmd_huge_page(*pmd)) + return (pte_t *)pmd; return pte_offset_kernel(pmd, addr); } EXPORT_SYMBOL(virt_to_pte); +pte_t *virt_to_kpte(unsigned long kaddr) +{ + BUG_ON(kaddr < PAGE_OFFSET); + return virt_to_pte(NULL, kaddr); +} +EXPORT_SYMBOL(virt_to_kpte); + pgprot_t set_remote_cache_cpu(pgprot_t prot, int cpu) { unsigned int width = smp_width; |