mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 05:04:00 +08:00
269833bd5a
Modern CPUs use fast-string instruction to accelerate copy performance, by combining data into 128 bit chunks. Modify comments and coding style to match it. Signed-off-by: Ma Ling <ling.ma@intel.com> Cc: iant@google.com Link: http://lkml.kernel.org/r/1350503565-19167-1-git-send-email-ling.ma@intel.com [ Cleaned up the clean up. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
111 lines
2.1 KiB
ArmAsm
111 lines
2.1 KiB
ArmAsm
/* Written 2003 by Andi Kleen, based on a kernel by Evandro Menezes */
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/dwarf2.h>
|
|
#include <asm/alternative-asm.h>
|
|
|
|
ALIGN
|
|
copy_page_rep:
|
|
CFI_STARTPROC
|
|
movl $4096/8, %ecx
|
|
rep movsq
|
|
ret
|
|
CFI_ENDPROC
|
|
ENDPROC(copy_page_rep)
|
|
|
|
/*
|
|
* Don't use streaming copy unless the CPU indicates X86_FEATURE_REP_GOOD.
|
|
* Could vary the prefetch distance based on SMP/UP.
|
|
*/
|
|
|
|
ENTRY(copy_page)
|
|
CFI_STARTPROC
|
|
subq $2*8, %rsp
|
|
CFI_ADJUST_CFA_OFFSET 2*8
|
|
movq %rbx, (%rsp)
|
|
CFI_REL_OFFSET rbx, 0
|
|
movq %r12, 1*8(%rsp)
|
|
CFI_REL_OFFSET r12, 1*8
|
|
|
|
movl $(4096/64)-5, %ecx
|
|
.p2align 4
|
|
.Loop64:
|
|
dec %rcx
|
|
movq 0x8*0(%rsi), %rax
|
|
movq 0x8*1(%rsi), %rbx
|
|
movq 0x8*2(%rsi), %rdx
|
|
movq 0x8*3(%rsi), %r8
|
|
movq 0x8*4(%rsi), %r9
|
|
movq 0x8*5(%rsi), %r10
|
|
movq 0x8*6(%rsi), %r11
|
|
movq 0x8*7(%rsi), %r12
|
|
|
|
prefetcht0 5*64(%rsi)
|
|
|
|
movq %rax, 0x8*0(%rdi)
|
|
movq %rbx, 0x8*1(%rdi)
|
|
movq %rdx, 0x8*2(%rdi)
|
|
movq %r8, 0x8*3(%rdi)
|
|
movq %r9, 0x8*4(%rdi)
|
|
movq %r10, 0x8*5(%rdi)
|
|
movq %r11, 0x8*6(%rdi)
|
|
movq %r12, 0x8*7(%rdi)
|
|
|
|
leaq 64 (%rsi), %rsi
|
|
leaq 64 (%rdi), %rdi
|
|
|
|
jnz .Loop64
|
|
|
|
movl $5, %ecx
|
|
.p2align 4
|
|
.Loop2:
|
|
decl %ecx
|
|
|
|
movq 0x8*0(%rsi), %rax
|
|
movq 0x8*1(%rsi), %rbx
|
|
movq 0x8*2(%rsi), %rdx
|
|
movq 0x8*3(%rsi), %r8
|
|
movq 0x8*4(%rsi), %r9
|
|
movq 0x8*5(%rsi), %r10
|
|
movq 0x8*6(%rsi), %r11
|
|
movq 0x8*7(%rsi), %r12
|
|
|
|
movq %rax, 0x8*0(%rdi)
|
|
movq %rbx, 0x8*1(%rdi)
|
|
movq %rdx, 0x8*2(%rdi)
|
|
movq %r8, 0x8*3(%rdi)
|
|
movq %r9, 0x8*4(%rdi)
|
|
movq %r10, 0x8*5(%rdi)
|
|
movq %r11, 0x8*6(%rdi)
|
|
movq %r12, 0x8*7(%rdi)
|
|
|
|
leaq 64(%rdi), %rdi
|
|
leaq 64(%rsi), %rsi
|
|
jnz .Loop2
|
|
|
|
movq (%rsp), %rbx
|
|
CFI_RESTORE rbx
|
|
movq 1*8(%rsp), %r12
|
|
CFI_RESTORE r12
|
|
addq $2*8, %rsp
|
|
CFI_ADJUST_CFA_OFFSET -2*8
|
|
ret
|
|
.Lcopy_page_end:
|
|
CFI_ENDPROC
|
|
ENDPROC(copy_page)
|
|
|
|
/* Some CPUs run faster using the string copy instructions.
|
|
It is also a lot simpler. Use this when possible */
|
|
|
|
#include <asm/cpufeature.h>
|
|
|
|
.section .altinstr_replacement,"ax"
|
|
1: .byte 0xeb /* jmp <disp8> */
|
|
.byte (copy_page_rep - copy_page) - (2f - 1b) /* offset */
|
|
2:
|
|
.previous
|
|
.section .altinstructions,"a"
|
|
altinstruction_entry copy_page, 1b, X86_FEATURE_REP_GOOD, \
|
|
.Lcopy_page_end-copy_page, 2b-1b
|
|
.previous
|