[PATCH 3/8] thp: introduce pmdp_invalidate()

From: Gerald Schaefer
Date: Thu Sep 06 2012 - 09:13:22 EST


On s390, a valid page table entry must not be changed while it is
attached to any CPU. So instead of pmd_mknotpresent() and set_pmd_at(),
an IDTE operation would be necessary there. This patch introduces the
pmdp_invalidate() function, to allow architecture-specific
implementations.

Signed-off-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
---
include/asm-generic/pgtable.h | 5 +++++
mm/huge_memory.c | 3 +--
mm/pgtable-generic.c | 11 +++++++++++
3 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 548a12e..e4821cf 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -170,6 +170,11 @@ extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm);
#endif

+#ifndef __HAVE_ARCH_PMDP_INVALIDATE
+extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp);
+#endif
+
#ifndef __HAVE_ARCH_PTE_SAME
static inline int pte_same(pte_t pte_a, pte_t pte_b)
{
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 5fce078..5617ee0 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1374,8 +1374,7 @@ static int __split_huge_page_map(struct page *page,
* SMP TLB and finally we write the non-huge version
* of the pmd entry with pmd_populate.
*/
- set_pmd_at(mm, address, pmd, pmd_mknotpresent(*pmd));
- flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+ pmdp_invalidate(vma, address, pmd);
pmd_populate(mm, pmd, pgtable);
ret = 1;
}
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 29867e0..e642627 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -159,3 +159,14 @@ pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
+
+#ifndef __HAVE_ARCH_PMDP_INVALIDATE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmdp)
+{
+ set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(*pmdp));
+ flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
--
1.7.11.5

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