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authorAneesh Kumar K.V2016-04-29 15:25:30 +0200
committerMichael Ellerman2016-05-01 10:32:21 +0200
commitc7d54842deb1fa357cff75b988275a1c9f259140 (patch)
treecab739cf4650a0397c0057a2878b386d613370a0 /arch/powerpc/include/asm/pte-common.h
parentpowerpc/mm: Use pte_raw() in pte_same()/pmd_same() (diff)
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powerpc/mm: Use _PAGE_READ to indicate Read access
This splits the _PAGE_RW bit into _PAGE_READ and _PAGE_WRITE. It also removes the dependency on _PAGE_USER for implying read only. Few things to note here is that, we have read implied with write and execute permission. Hence we should always find _PAGE_READ set on hash pte fault. We still can't switch PROT_NONE to !(_PAGE_RWX). Auto numa depends on marking a prot none pte _PAGE_WRITE. (For more details look at b191f9b106ea "mm: numa: preserve PTE write permissions across a NUMA hinting fault") Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm/pte-common.h')
-rw-r--r--arch/powerpc/include/asm/pte-common.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index 1ec67b043065..9f5dea58b0db 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -198,3 +198,8 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
/* Advertise support for _PAGE_SPECIAL */
#define __HAVE_ARCH_PTE_SPECIAL
+#ifndef _PAGE_READ
+/* if not defined, we should not find _PAGE_WRITE too */
+#define _PAGE_READ 0
+#define _PAGE_WRITE _PAGE_RW
+#endif