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GBPAGES: Fix global bit for 64bit

PATCH In review Andi Kleen 2 participants 3 messages Jan 31, 2008

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Andi Kleen

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#0 lore raw

PATCH 1/1 GBPAGES: Fix global bit for 64bit

[Ideally apply before the patch to enable gbpages direct mapping]

The gbpages direct patch assumed that __PAGE_KERNEL contains _PAGE_GLOBAL (I think because that was true at some point in git-x86 and i forgot to remove it again when forward porting)

This is currently true on 32bit, but not on 64bit which does not make much sense. Add it to 64bit too. Also get rid of the obsolete MAKE_GLOBAL.

include/asm-x86/pgtable.h +13 -17
Index: linux/include/asm-x86/pgtable.h
===================================================================
@@ -69,11 +69,13 @@
 #define _PAGE_KERNEL (_PAGE_KERNEL_EXEC | _PAGE_NX)
 
 #ifndef __ASSEMBLY__
+/* These are set up based on CPUID capabilities */
 extern pteval_t __PAGE_KERNEL, __PAGE_KERNEL_EXEC;
 #endif	/* __ASSEMBLY__ */
 #else
+/* 64bit can assume more CPUID capabilities */
 #define __PAGE_KERNEL_EXEC						\
-	(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
+	(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL)
 #define __PAGE_KERNEL		(__PAGE_KERNEL_EXEC | _PAGE_NX)
 #endif
 
@@ -86,22 +88,16 @@ extern pteval_t __PAGE_KERNEL, __PAGE_KE
 #define __PAGE_KERNEL_LARGE		(__PAGE_KERNEL | _PAGE_PSE)
 #define __PAGE_KERNEL_LARGE_EXEC	(__PAGE_KERNEL_EXEC | _PAGE_PSE)
 
-#ifdef CONFIG_X86_32
-# define MAKE_GLOBAL(x)			__pgprot((x))
-#else
-# define MAKE_GLOBAL(x)			__pgprot((x) | _PAGE_GLOBAL)
-#endif
-
-#define PAGE_KERNEL			MAKE_GLOBAL(__PAGE_KERNEL)
-#define PAGE_KERNEL_RO			MAKE_GLOBAL(__PAGE_KERNEL_RO)
-#define PAGE_KERNEL_EXEC		MAKE_GLOBAL(__PAGE_KERNEL_EXEC)
-#define PAGE_KERNEL_RX			MAKE_GLOBAL(__PAGE_KERNEL_RX)
-#define PAGE_KERNEL_NOCACHE		MAKE_GLOBAL(__PAGE_KERNEL_NOCACHE)
-#define PAGE_KERNEL_EXEC_NOCACHE	MAKE_GLOBAL(__PAGE_KERNEL_EXEC_NOCACHE)
-#define PAGE_KERNEL_LARGE		MAKE_GLOBAL(__PAGE_KERNEL_LARGE)
-#define PAGE_KERNEL_LARGE_EXEC		MAKE_GLOBAL(__PAGE_KERNEL_LARGE_EXEC)
-#define PAGE_KERNEL_VSYSCALL		MAKE_GLOBAL(__PAGE_KERNEL_VSYSCALL)
-#define PAGE_KERNEL_VSYSCALL_NOCACHE	MAKE_GLOBAL(__PAGE_KERNEL_VSYSCALL_NOCACHE)
+#define PAGE_KERNEL			__pgprot(__PAGE_KERNEL)
+#define PAGE_KERNEL_RO			__pgprot(__PAGE_KERNEL_RO)
+#define PAGE_KERNEL_EXEC		__pgprot(__PAGE_KERNEL_EXEC)
+#define PAGE_KERNEL_RX			__pgprot(__PAGE_KERNEL_RX)
+#define PAGE_KERNEL_NOCACHE		__pgprot(__PAGE_KERNEL_NOCACHE)
+#define PAGE_KERNEL_EXEC_NOCACHE	__pgprot(__PAGE_KERNEL_EXEC_NOCACHE)
+#define PAGE_KERNEL_LARGE		__pgprot(__PAGE_KERNEL_LARGE)
+#define PAGE_KERNEL_LARGE_EXEC		__pgprot(__PAGE_KERNEL_LARGE_EXEC)
+#define PAGE_KERNEL_VSYSCALL		__pgprot(__PAGE_KERNEL_VSYSCALL)
+#define PAGE_KERNEL_VSYSCALL_NOCACHE	__pgprot(__PAGE_KERNEL_VSYSCALL_NOCACHE)
 
 /*         xwr */
 #define __P000	PAGE_NONE
#1 lore raw
Quoted 8 lines · Andi Kleen

[Ideally apply before the patch to enable gbpages direct mapping]

The gbpages direct patch assumed that __PAGE_KERNEL contains _PAGE_GLOBAL (I think because that was true at some point in git-x86 and i forgot to remove it again when forward porting)

This is currently true on 32bit, but not on 64bit which does not make much sense. Add it to 64bit too. Also get rid of the obsolete MAKE_GLOBAL.

Last time when my patch to do this was in the tree, it caused random things to fail, even after increasing the strength of various tlb flushes. Did you change something to fix this?

J

Quoted 55 lines

Index: linux/include/asm-x86/pgtable.h
===================================================================

include/asm-x86/pgtable.h +13 -17
@@ -69,11 +69,13 @@
 #define _PAGE_KERNEL (_PAGE_KERNEL_EXEC | _PAGE_NX)
 
 #ifndef __ASSEMBLY__
+/* These are set up based on CPUID capabilities */
 extern pteval_t __PAGE_KERNEL, __PAGE_KERNEL_EXEC;
 #endif	/* __ASSEMBLY__ */
 #else
+/* 64bit can assume more CPUID capabilities */
 #define __PAGE_KERNEL_EXEC						\
-	(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
+	(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL)
 #define __PAGE_KERNEL		(__PAGE_KERNEL_EXEC | _PAGE_NX)
 #endif
 
@@ -86,22 +88,16 @@ extern pteval_t __PAGE_KERNEL, __PAGE_KE
 #define __PAGE_KERNEL_LARGE		(__PAGE_KERNEL | _PAGE_PSE)
 #define __PAGE_KERNEL_LARGE_EXEC	(__PAGE_KERNEL_EXEC | _PAGE_PSE)
 
-#ifdef CONFIG_X86_32
-# define MAKE_GLOBAL(x)			__pgprot((x))
-#else
-# define MAKE_GLOBAL(x)			__pgprot((x) | _PAGE_GLOBAL)
-#endif
-
-#define PAGE_KERNEL			MAKE_GLOBAL(__PAGE_KERNEL)
-#define PAGE_KERNEL_RO			MAKE_GLOBAL(__PAGE_KERNEL_RO)
-#define PAGE_KERNEL_EXEC		MAKE_GLOBAL(__PAGE_KERNEL_EXEC)
-#define PAGE_KERNEL_RX			MAKE_GLOBAL(__PAGE_KERNEL_RX)
-#define PAGE_KERNEL_NOCACHE		MAKE_GLOBAL(__PAGE_KERNEL_NOCACHE)
-#define PAGE_KERNEL_EXEC_NOCACHE	MAKE_GLOBAL(__PAGE_KERNEL_EXEC_NOCACHE)
-#define PAGE_KERNEL_LARGE		MAKE_GLOBAL(__PAGE_KERNEL_LARGE)
-#define PAGE_KERNEL_LARGE_EXEC		MAKE_GLOBAL(__PAGE_KERNEL_LARGE_EXEC)
-#define PAGE_KERNEL_VSYSCALL		MAKE_GLOBAL(__PAGE_KERNEL_VSYSCALL)
-#define PAGE_KERNEL_VSYSCALL_NOCACHE	MAKE_GLOBAL(__PAGE_KERNEL_VSYSCALL_NOCACHE)
+#define PAGE_KERNEL			__pgprot(__PAGE_KERNEL)
+#define PAGE_KERNEL_RO			__pgprot(__PAGE_KERNEL_RO)
+#define PAGE_KERNEL_EXEC		__pgprot(__PAGE_KERNEL_EXEC)
+#define PAGE_KERNEL_RX			__pgprot(__PAGE_KERNEL_RX)
+#define PAGE_KERNEL_NOCACHE		__pgprot(__PAGE_KERNEL_NOCACHE)
+#define PAGE_KERNEL_EXEC_NOCACHE	__pgprot(__PAGE_KERNEL_EXEC_NOCACHE)
+#define PAGE_KERNEL_LARGE		__pgprot(__PAGE_KERNEL_LARGE)
+#define PAGE_KERNEL_LARGE_EXEC		__pgprot(__PAGE_KERNEL_LARGE_EXEC)
+#define PAGE_KERNEL_VSYSCALL		__pgprot(__PAGE_KERNEL_VSYSCALL)
+#define PAGE_KERNEL_VSYSCALL_NOCACHE	__pgprot(__PAGE_KERNEL_VSYSCALL_NOCACHE)
 
 /*         xwr */
 #define __P000	PAGE_NONE
author
#2 lore raw
Quoted 3 lines

Last time when my patch to do this was in the tree, it caused random things to fail, even after increasing the strength of various tlb flushes. Did you change something to fix this?

At least all the flushes in init_64 are global now.

But my latest iteration of gbpages actually doesn't need this patch anymore because I'm back to using PAGE_KERNEL_LARGE (without underscores)

-Andi