diff options
| author | Yang Shi | 2016-04-29 14:07:54 -0700 |
|---|---|---|
| committer | Will Deacon | 2016-05-03 09:58:38 +0100 |
| commit | 2326df551b137dd88652b54016905e13579b7a25 (patch) | |
| tree | 2607d23e6109eb13ed2595bdf0a8e17133d050ac | |
| parent | c612505f860c6d4fac03924879982adcd042e239 (diff) | |
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>
| -rw-r--r-- | arch/arm64/include/asm/pgtable-types.h | 32 |
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 |