powerpc/mm: Add option for non-atomic PTE updates to ppc64
ppc32 has it already, add it to ppc64 as a preliminary for adding
support for Book3E 64-bit support
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index 768e0f0..c40db05 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -178,6 +178,7 @@
pte_t *ptep, unsigned long clr,
int huge)
{
+#ifdef PTE_ATOMIC_UPDATES
unsigned long old, tmp;
__asm__ __volatile__(
@@ -190,7 +191,10 @@
: "=&r" (old), "=&r" (tmp), "=m" (*ptep)
: "r" (ptep), "r" (clr), "m" (*ptep), "i" (_PAGE_BUSY)
: "cc" );
-
+#else
+ unsigned long old = pte_val(*ptep);
+ *ptep = __pte(old & ~clr);
+#endif
/* huge pages use the old page table lock */
if (!huge)
assert_pte_locked(mm, addr);
@@ -278,6 +282,8 @@
unsigned long bits = pte_val(entry) &
(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW |
_PAGE_EXEC | _PAGE_HWEXEC);
+
+#ifdef PTE_ATOMIC_UPDATES
unsigned long old, tmp;
__asm__ __volatile__(
@@ -290,6 +296,10 @@
:"=&r" (old), "=&r" (tmp), "=m" (*ptep)
:"r" (bits), "r" (ptep), "m" (*ptep), "i" (_PAGE_BUSY)
:"cc");
+#else
+ unsigned long old = pte_val(*ptep);
+ *ptep = __pte(old | bits);
+#endif
}
#define __HAVE_ARCH_PTE_SAME