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-rw-r--r--arch/arm/mm/fault-armv.c85
1 files changed, 46 insertions, 39 deletions
diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index 56ee153..c9b97e9 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -36,28 +36,12 @@ static unsigned long shared_pte_mask = L_PTE_MT_BUFFERABLE;
* Therefore those configurations which might call adjust_pte (those
* without CONFIG_CPU_CACHE_VIPT) cannot support split page_table_lock.
*/
-static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
+static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address,
+ unsigned long pfn, pte_t *ptep)
{
- pgd_t *pgd;
- pmd_t *pmd;
- pte_t *pte, entry;
+ pte_t entry = *ptep;
int ret;
- pgd = pgd_offset(vma->vm_mm, address);
- if (pgd_none(*pgd))
- goto no_pgd;
- if (pgd_bad(*pgd))
- goto bad_pgd;
-
- pmd = pmd_offset(pgd, address);
- if (pmd_none(*pmd))
- goto no_pmd;
- if (pmd_bad(*pmd))
- goto bad_pmd;
-
- pte = pte_offset_map(pmd, address);
- entry = *pte;
-
/*
* If this page is present, it's actually being shared.
*/
@@ -68,33 +52,55 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address)
* fault (ie, is old), we can safely ignore any issues.
*/
if (ret && (pte_val(entry) & L_PTE_MT_MASK) != shared_pte_mask) {
- unsigned long pfn = pte_pfn(entry);
flush_cache_page(vma, address, pfn);
outer_flush_range((pfn << PAGE_SHIFT),
(pfn << PAGE_SHIFT) + PAGE_SIZE);
pte_val(entry) &= ~L_PTE_MT_MASK;
pte_val(entry) |= shared_pte_mask;
- set_pte_at(vma->vm_mm, address, pte, entry);
+ set_pte_at(vma->vm_mm, address, ptep, entry);
flush_tlb_page(vma, address);
}
- pte_unmap(pte);
+
return ret;
+}
+
+static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
+ unsigned long pfn)
+{
+ spinlock_t *ptl;
+ pgd_t *pgd;
+ pmd_t *pmd;
+ pte_t *pte;
+ int ret;
+
+ pgd = pgd_offset(vma->vm_mm, address);
+ if (pgd_none_or_clear_bad(pgd))
+ return 0;
+
+ pmd = pmd_offset(pgd, address);
+ if (pmd_none_or_clear_bad(pmd))
+ return 0;
-bad_pgd:
- pgd_ERROR(*pgd);
- pgd_clear(pgd);
-no_pgd:
- return 0;
-
-bad_pmd:
- pmd_ERROR(*pmd);
- pmd_clear(pmd);
-no_pmd:
- return 0;
+ /*
+ * This is called while another page table is mapped, so we
+ * must use the nested version. This also means we need to
+ * open-code the spin-locking.
+ */
+ ptl = pte_lockptr(vma->vm_mm, pmd);
+ pte = pte_offset_map_nested(pmd, address);
+ spin_lock(ptl);
+
+ ret = do_adjust_pte(vma, address, pfn, pte);
+
+ spin_unlock(ptl);
+ pte_unmap_nested(pte);
+
+ return ret;
}
static void
-make_coherent(struct address_space *mapping, struct vm_area_struct *vma, unsigned long addr, unsigned long pfn)
+make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep, unsigned long pfn)
{
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *mpnt;
@@ -122,11 +128,11 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, unsigne
if (!(mpnt->vm_flags & VM_MAYSHARE))
continue;
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
- aliases += adjust_pte(mpnt, mpnt->vm_start + offset);
+ aliases += adjust_pte(mpnt, mpnt->vm_start + offset, pfn);
}
flush_dcache_mmap_unlock(mapping);
if (aliases)
- adjust_pte(vma, addr);
+ do_adjust_pte(vma, addr, pfn, ptep);
else
flush_cache_page(vma, addr, pfn);
}
@@ -144,9 +150,10 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma, unsigne
*
* Note that the pte lock will be held.
*/
-void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr,
+ pte_t *ptep)
{
- unsigned long pfn = pte_pfn(pte);
+ unsigned long pfn = pte_pfn(*ptep);
struct address_space *mapping;
struct page *page;
@@ -168,7 +175,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
#endif
if (mapping) {
if (cache_is_vivt())
- make_coherent(mapping, vma, addr, pfn);
+ make_coherent(mapping, vma, addr, ptep, pfn);
else if (vma->vm_flags & VM_EXEC)
__flush_icache_all();
}
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