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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-03-19 19:34:08 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-03-24 13:47:33 +1100
commit8d1cf34e7ad5c7738ce20d20bd7f002f562cb8b5 (patch)
treef731b8b2d3e71e7287bed977bdd7fc9ea6942d45 /arch/powerpc/include/asm/pgtable-ppc32.h
parent2a7d55fda58eb4e3652252d4f71222bd1ff90c5e (diff)
downloadop-kernel-dev-8d1cf34e7ad5c7738ce20d20bd7f002f562cb8b5.zip
op-kernel-dev-8d1cf34e7ad5c7738ce20d20bd7f002f562cb8b5.tar.gz
powerpc/mm: Tweak PTE bit combination definitions
This patch tweaks the way some PTE bit combinations are defined, in such a way that the 32 and 64-bit variant become almost identical and that will make it easier to bring in a new common pte-* file for the new variant of the Book3-E support. The combination of bits defining access to kernel pages are now clearly separated from the combination used by userspace and the core VM. The resulting generated code should remain identical unless I made a mistake. Note: While at it, I removed a non-sensical statement related to CONFIG_KGDB in ppc_mmu_32.c which could cause kernel mappings to be user accessible when that option is enabled. Probably something that bitrot. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm/pgtable-ppc32.h')
-rw-r--r--arch/powerpc/include/asm/pgtable-ppc32.h41
1 files changed, 20 insertions, 21 deletions
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 67ceffc..7ce331e 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -144,6 +144,13 @@ extern int icache_44x_need_flush;
#define PMD_PAGE_SIZE(pmd) bad_call_to_PMD_PAGE_SIZE()
#endif
+#ifndef _PAGE_KERNEL_RO
+#define _PAGE_KERNEL_RO 0
+#endif
+#ifndef _PAGE_KERNEL_RW
+#define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW | _PAGE_HWWRITE)
+#endif
+
#define _PAGE_HPTEFLAGS _PAGE_HASHPTE
/* Location of the PFN in the PTE. Most platforms use the same as _PAGE_SHIFT
@@ -186,30 +193,25 @@ extern int icache_44x_need_flush;
#else
#define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED)
#endif
-#define _PAGE_BASE_NC (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_NO_CACHE)
-
-#define _PAGE_WRENABLE (_PAGE_RW | _PAGE_DIRTY | _PAGE_HWWRITE)
-#define _PAGE_KERNEL (_PAGE_BASE | _PAGE_SHARED | _PAGE_WRENABLE)
-#define _PAGE_KERNEL_NC (_PAGE_BASE_NC | _PAGE_SHARED | _PAGE_WRENABLE)
-
-#ifdef CONFIG_PPC_STD_MMU
-/* On standard PPC MMU, no user access implies kernel read/write access,
- * so to write-protect kernel memory we must turn on user access */
-#define _PAGE_KERNEL_RO (_PAGE_BASE | _PAGE_SHARED | _PAGE_USER)
-#else
-#define _PAGE_KERNEL_RO (_PAGE_BASE | _PAGE_SHARED)
-#endif
-
-#define _PAGE_IO (_PAGE_KERNEL_NC | _PAGE_GUARDED)
-#define _PAGE_RAM (_PAGE_KERNEL | _PAGE_HWEXEC)
+#define _PAGE_BASE_NC (_PAGE_PRESENT | _PAGE_ACCESSED)
+
+/* Permission masks used for kernel mappings */
+#define PAGE_KERNEL __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
+#define PAGE_KERNEL_NC __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
+ _PAGE_NO_CACHE)
+#define PAGE_KERNEL_NCG __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
+ _PAGE_NO_CACHE | _PAGE_GUARDED)
+#define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW | _PAGE_EXEC)
+#define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
+#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO | _PAGE_EXEC)
#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
defined(CONFIG_KPROBES)
/* We want the debuggers to be able to set breakpoints anywhere, so
* don't write protect the kernel text */
-#define _PAGE_RAM_TEXT _PAGE_RAM
+#define PAGE_KERNEL_TEXT PAGE_KERNEL_X
#else
-#define _PAGE_RAM_TEXT (_PAGE_KERNEL_RO | _PAGE_HWEXEC)
+#define PAGE_KERNEL_TEXT PAGE_KERNEL_ROX
#endif
#define PAGE_NONE __pgprot(_PAGE_BASE)
@@ -220,9 +222,6 @@ extern int icache_44x_need_flush;
#define PAGE_COPY __pgprot(_PAGE_BASE | _PAGE_USER)
#define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
-#define PAGE_KERNEL __pgprot(_PAGE_RAM)
-#define PAGE_KERNEL_NOCACHE __pgprot(_PAGE_IO)
-
/*
* The PowerPC can only do execute protection on a segment (256MB) basis,
* not on a page basis. So we consider execute permission the same as read.
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