linux-stable/arch/x86/lib/clear_page_64.S
Alexey Dobriyan 16c5055a5f x86/asm: Trim clear_page.S includes
After alternatives were shifted to the call site, only 2 headers are
necessary.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180113190648.GB23111@avx2
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-13 17:37:07 +01:00

51 lines
907 B
ArmAsm

#include <linux/linkage.h>
#include <asm/export.h>
/*
* Most CPUs support enhanced REP MOVSB/STOSB instructions. It is
* recommended to use this when possible and we do use them by default.
* If enhanced REP MOVSB/STOSB is not available, try to use fast string.
* Otherwise, use original.
*/
/*
* Zero a page.
* %rdi - page
*/
ENTRY(clear_page_rep)
movl $4096/8,%ecx
xorl %eax,%eax
rep stosq
ret
ENDPROC(clear_page_rep)
EXPORT_SYMBOL_GPL(clear_page_rep)
ENTRY(clear_page_orig)
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
ENDPROC(clear_page_orig)
EXPORT_SYMBOL_GPL(clear_page_orig)
ENTRY(clear_page_erms)
movl $4096,%ecx
xorl %eax,%eax
rep stosb
ret
ENDPROC(clear_page_erms)
EXPORT_SYMBOL_GPL(clear_page_erms)