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authorYang Shi <yang.shi@linaro.org>2016-04-29 14:07:54 -0700
committerWill Deacon <will.deacon@arm.com>2016-05-03 09:58:38 +0100
commit2326df551b137dd88652b54016905e13579b7a25 (patch)
tree2607d23e6109eb13ed2595bdf0a8e17133d050ac /arch/arm64/include/asm
parentc612505f860c6d4fac03924879982adcd042e239 (diff)
downloadlinux-2326df551b137dd88652b54016905e13579b7a25.tar.gz
arm64: always use STRICT_MM_TYPECHECKS
Inspired by the counterpart of powerpc [1], which shows there is no negative effect on code generation from enabling STRICT_MM_TYPECHECKS with a modern compiler. And, Arnd's comment [2] about that patch says STRICT_MM_TYPECHECKS could be default as long as the architecture can pass structures in registers as function arguments. ARM64 can do it as long as the size of structure <= 16 bytes. All the page table value types are u64 on ARM64. The below disassembly demonstrates it, entry is pte_t type: entry = arch_make_huge_pte(entry, vma, page, writable); 0xffff00000826fc38 <+80>: and x0, x0, #0xfffffffffffffffd 0xffff00000826fc3c <+84>: mov w3, w21 0xffff00000826fc40 <+88>: mov x2, x20 0xffff00000826fc44 <+92>: mov x1, x19 0xffff00000826fc48 <+96>: orr x0, x0, #0x400 0xffff00000826fc4c <+100>: bl 0xffff00000809bcc0 <arch_make_huge_pte> [1] http://www.spinics.net/lists/linux-mm/msg105951.html [2] http://www.spinics.net/lists/linux-mm/msg105969.html Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/include/asm')
-rw-r--r--arch/arm64/include/asm/pgtable-types.h32
1 files changed, 0 insertions, 32 deletions
diff --git a/arch/arm64/include/asm/pgtable-types.h b/arch/arm64/include/asm/pgtable-types.h
index 2b1bd7e52c3b..69b2fd41503c 100644
--- a/arch/arm64/include/asm/pgtable-types.h
+++ b/arch/arm64/include/asm/pgtable-types.h
@@ -27,10 +27,6 @@ typedef u64 pmdval_t;
typedef u64 pudval_t;
typedef u64 pgdval_t;
-#undef STRICT_MM_TYPECHECKS
-
-#ifdef STRICT_MM_TYPECHECKS
-
/*
* These are used to make use of C type-checking..
*/
@@ -58,34 +54,6 @@ typedef struct { pteval_t pgprot; } pgprot_t;
#define pgprot_val(x) ((x).pgprot)
#define __pgprot(x) ((pgprot_t) { (x) } )
-#else /* !STRICT_MM_TYPECHECKS */
-
-typedef pteval_t pte_t;
-#define pte_val(x) (x)
-#define __pte(x) (x)
-
-#if CONFIG_PGTABLE_LEVELS > 2
-typedef pmdval_t pmd_t;
-#define pmd_val(x) (x)
-#define __pmd(x) (x)
-#endif
-
-#if CONFIG_PGTABLE_LEVELS > 3
-typedef pudval_t pud_t;
-#define pud_val(x) (x)
-#define __pud(x) (x)
-#endif
-
-typedef pgdval_t pgd_t;
-#define pgd_val(x) (x)
-#define __pgd(x) (x)
-
-typedef pteval_t pgprot_t;
-#define pgprot_val(x) (x)
-#define __pgprot(x) (x)
-
-#endif /* STRICT_MM_TYPECHECKS */
-
#if CONFIG_PGTABLE_LEVELS == 2
#include <asm-generic/pgtable-nopmd.h>
#elif CONFIG_PGTABLE_LEVELS == 3