diff options
| author | Alexander Duyck <alexander.h.duyck@intel.com> | 2012-11-16 22:55:46 +0100 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2012-11-17 01:42:09 +0100 |
| commit | 7d74275d39def4d3ccc8cf4725388bf79ef13861 (patch) | |
| tree | afe6ed01aad5df44f82aa576151eeabd2e9b66b6 | |
| parent | x86: Improve __phys_addr performance by making use of carry flags and inlining (diff) | |
| download | linux-7d74275d39def4d3ccc8cf4725388bf79ef13861.tar.xz linux-7d74275d39def4d3ccc8cf4725388bf79ef13861.zip | |
x86: Make it so that __pa_symbol can only process kernel symbols on x86_64
I submitted an earlier patch that make __phys_addr an inline. This obviously
results in an increase in the code size. One step I can take to reduce that
is to make it so that the __pa_symbol call does a direct translation for
kernel addresses instead of covering all of virtual memory.
On my system this reduced the size for __pa_symbol from 5 instructions
totalling 30 bytes to 3 instructions totalling 16 bytes.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Link: http://lkml.kernel.org/r/20121116215356.8521.92472.stgit@ahduyck-cp1.jf.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| -rw-r--r-- | arch/x86/include/asm/page.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/page_32.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/page_64.h | 3 | ||||
| -rw-r--r-- | arch/x86/mm/physaddr.c | 11 |
4 files changed, 17 insertions, 1 deletions
diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h index 8ca82839288a..3698a6a0a940 100644 --- a/arch/x86/include/asm/page.h +++ b/arch/x86/include/asm/page.h @@ -44,7 +44,8 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr, * case properly. Once all supported versions of gcc understand it, we can * remove this Voodoo magic stuff. (i.e. once gcc3.x is deprecated) */ -#define __pa_symbol(x) __pa(__phys_reloc_hide((unsigned long)(x))) +#define __pa_symbol(x) \ + __phys_addr_symbol(__phys_reloc_hide((unsigned long)(x))) #define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET)) diff --git a/arch/x86/include/asm/page_32.h b/arch/x86/include/asm/page_32.h index da4e762406f7..4d550d04b609 100644 --- a/arch/x86/include/asm/page_32.h +++ b/arch/x86/include/asm/page_32.h @@ -15,6 +15,7 @@ extern unsigned long __phys_addr(unsigned long); #else #define __phys_addr(x) __phys_addr_nodebug(x) #endif +#define __phys_addr_symbol(x) __phys_addr(x) #define __phys_reloc_hide(x) RELOC_HIDE((x), 0) #ifdef CONFIG_FLATMEM diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h index 5138174c2101..0f1ddee6a0ce 100644 --- a/arch/x86/include/asm/page_64.h +++ b/arch/x86/include/asm/page_64.h @@ -21,8 +21,11 @@ static inline unsigned long __phys_addr_nodebug(unsigned long x) #ifdef CONFIG_DEBUG_VIRTUAL extern unsigned long __phys_addr(unsigned long); +extern unsigned long __phys_addr_symbol(unsigned long); #else #define __phys_addr(x) __phys_addr_nodebug(x) +#define __phys_addr_symbol(x) \ + ((unsigned long)(x) - __START_KERNEL_map + phys_base) #endif #define __phys_reloc_hide(x) (x) diff --git a/arch/x86/mm/physaddr.c b/arch/x86/mm/physaddr.c index fd40d75109ef..c73feddd518d 100644 --- a/arch/x86/mm/physaddr.c +++ b/arch/x86/mm/physaddr.c @@ -28,6 +28,17 @@ unsigned long __phys_addr(unsigned long x) return x; } EXPORT_SYMBOL(__phys_addr); + +unsigned long __phys_addr_symbol(unsigned long x) +{ + unsigned long y = x - __START_KERNEL_map; + + /* only check upper bounds since lower bounds will trigger carry */ + VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE); + + return y + phys_base; +} +EXPORT_SYMBOL(__phys_addr_symbol); #endif bool __virt_addr_valid(unsigned long x) |