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author | Dave Kleikamp <shaggy@austin.ibm.com> | 2006-03-14 17:05:45 -0600 |
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committer | Dave Kleikamp <shaggy@austin.ibm.com> | 2006-03-14 17:05:45 -0600 |
commit | c5111f504d2a9b0d258d7c4752b4093523315989 (patch) | |
tree | 6a52864aff79691689aea21cb0cb928327d5de5b /arch/x86_64/lib/clear_page.S | |
parent | 69eb66d7da7dba2696281981347698e1693c2340 (diff) | |
parent | a488edc914aa1d766a4e2c982b5ae03d5657ec1b (diff) |
Merge with /home/shaggy/git/linus-clean/
Diffstat (limited to 'arch/x86_64/lib/clear_page.S')
-rw-r--r-- | arch/x86_64/lib/clear_page.S | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/x86_64/lib/clear_page.S b/arch/x86_64/lib/clear_page.S index 43d9fa13618..1f81b79b796 100644 --- a/arch/x86_64/lib/clear_page.S +++ b/arch/x86_64/lib/clear_page.S @@ -5,8 +5,46 @@ .globl clear_page .p2align 4 clear_page: + xorl %eax,%eax + movl $4096/64,%ecx + .p2align 4 +.Lloop: + decl %ecx +#define PUT(x) movq %rax,x*8(%rdi) + movq %rax,(%rdi) + PUT(1) + PUT(2) + PUT(3) + PUT(4) + PUT(5) + PUT(6) + PUT(7) + leaq 64(%rdi),%rdi + jnz .Lloop + nop + ret +clear_page_end: + + /* Some CPUs run faster using the string instructions. + It is also a lot simpler. Use this when possible */ + +#include <asm/cpufeature.h> + + .section .altinstructions,"a" + .align 8 + .quad clear_page + .quad clear_page_c + .byte X86_FEATURE_REP_GOOD + .byte clear_page_end-clear_page + .byte clear_page_c_end-clear_page_c + .previous + + .section .altinstr_replacement,"ax" +clear_page_c: movl $4096/8,%ecx xorl %eax,%eax rep stosq ret +clear_page_c_end: + .previous |