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authorGerald Schaefer <gerald.schaefer@de.ibm.com>2012-10-08 16:30:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-09 16:22:30 +0900
commit75077afbec1ac89178c1542b23a70d0f960b0aaf (patch)
tree843b8a7175de7a9a2dca37d877cd742121f4b627 /arch/s390/include/asm/pgtable.h
parent8e72033f2a489b6c98c4e3c7cc281b1afd6cb85c (diff)
thp, s390: thp splitting backend for s390
This patch is part of the architecture backend for thp on s390. It provides the functions related to thp splitting, including serialization against gup. Unlike other archs, pmdp_splitting_flush() cannot use a tlb flushing operation to serialize against gup on s390, because that wouldn't be stopped by the disabled IRQs. So instead, smp_call_function() is called with an empty function, which will have the expected effect. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/s390/include/asm/pgtable.h')
-rw-r--r--arch/s390/include/asm/pgtable.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 6bd7d7483017..c3f0775e71f1 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -347,6 +347,8 @@ extern struct page *vmemmap;
#define _SEGMENT_ENTRY_LARGE 0x400 /* STE-format control, large page */
#define _SEGMENT_ENTRY_CO 0x100 /* change-recording override */
+#define _SEGMENT_ENTRY_SPLIT_BIT 0 /* THP splitting bit number */
+#define _SEGMENT_ENTRY_SPLIT (1UL << _SEGMENT_ENTRY_SPLIT_BIT)
/* Page status table bits for virtualization */
#define RCP_ACC_BITS 0xf000000000000000UL
@@ -506,6 +508,10 @@ static inline int pmd_bad(pmd_t pmd)
return (pmd_val(pmd) & mask) != _SEGMENT_ENTRY;
}
+#define __HAVE_ARCH_PMDP_SPLITTING_FLUSH
+extern void pmdp_splitting_flush(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t *pmdp);
+
static inline int pte_none(pte_t pte)
{
return (pte_val(pte) & _PAGE_INVALID) && !(pte_val(pte) & _PAGE_SWT);
@@ -1159,6 +1165,13 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
#define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
#define pte_unmap(pte) do { } while (0)
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline int pmd_trans_splitting(pmd_t pmd)
+{
+ return pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
/*
* 31 bit swap entry format:
* A page-table entry has some bits we have to treat in a special way.