page fault scalability patch V10: [6/7] x86_64 atomic pte operations

[Christoph Lameter]

Changelog
	* Provide atomic pte operations for x86_64

Signed-off-by: Christoph Lameter <clameter@xxxxxxx>

Index: linux-2.6.9-rc4/include/asm-x86_64/pgalloc.h
===================================================================
--- linux-2.6.9-rc4.orig/include/asm-x86_64/pgalloc.h	2004-10-10 19:57:59.000000000 -0700
+++ linux-2.6.9-rc4/include/asm-x86_64/pgalloc.h	2004-10-15 11:20:36.000000000 -0700
@@ -7,16 +7,26 @@
 #include <linux/threads.h>
 #include <linux/mm.h>

+#define PMD_NONE 0
+#define PGD_NONE 0
+
 #define pmd_populate_kernel(mm, pmd, pte) \
 		set_pmd(pmd, __pmd(_PAGE_TABLE | __pa(pte)))
 #define pgd_populate(mm, pgd, pmd) \
 		set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(pmd)))
+#define pgd_test_and_populate(mm, pgd, pmd) \
+		(cmpxchg((int *)pgd, PGD_NONE, _PAGE_TABLE | __pa(pmd)) == PGD_NONE)

 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *pte)
 {
 	set_pmd(pmd, __pmd(_PAGE_TABLE | (page_to_pfn(pte) << PAGE_SHIFT)));
 }

+static inline int pmd_test_and_populate(struct mm_struct *mm, pmd_t *pmd, struct page *pte)
+{
+	return cmpxchg((int *)pmd, PMD_NONE, _PAGE_TABLE | (page_to_pfn(pte) << PAGE_SHIFT)) == PMD_NONE;
+}
+
 extern __inline__ pmd_t *get_pmd(void)
 {
 	return (pmd_t *)get_zeroed_page(GFP_KERNEL);
Index: linux-2.6.9-rc4/include/asm-x86_64/pgtable.h
===================================================================
--- linux-2.6.9-rc4.orig/include/asm-x86_64/pgtable.h	2004-10-10 19:58:23.000000000 -0700
+++ linux-2.6.9-rc4/include/asm-x86_64/pgtable.h	2004-10-15 11:21:27.000000000 -0700
@@ -436,6 +436,11 @@
 #define	kc_offset_to_vaddr(o) \
    (((o) & (1UL << (__VIRTUAL_MASK_SHIFT-1))) ? ((o) | (~__VIRTUAL_MASK)) : (o))

+
+#define ptep_xchg(addr,xp,newval)	__pte(xchg(&(xp)->pte, pte_val(newval)))
+#define ptep_cmpxchg(mm,addr,xp,oldval,newval) (cmpxchg(&(xp)->pte, pte_val(oldval), pte_val(newval)) == pte_val(oldval))
+#define __HAVE_ARCH_ATOMIC_TABLE_OPS
+
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
-
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