projects / thirdparty / kernel / stable.git / blame
| Commit | Line | Data |
|---|---|---|
| 8d379dad JB |
1 | #include <linux/linkage.h> |
| 2 | #include <asm/dwarf2.h> | |
| e365c9df | 3 | #include <asm/alternative-asm.h> |
| 8d379dad | 4 | |
| 1da177e4 LT |
5 | /* |
| 6 | * Zero a page. | |
| 7 | * rdi page | |
| 8 | */ | |
| 9e314996 | 9 | ENTRY(clear_page_c) |
| 8d379dad JB |
10 | CFI_STARTPROC |
| 11 | movl $4096/8,%ecx | |
| 12 | xorl %eax,%eax | |
| 13 | rep stosq | |
| 14 | ret | |
| 15 | CFI_ENDPROC | |
| 9e314996 | 16 | ENDPROC(clear_page_c) |
| 8d379dad | 17 | |
| e365c9df FY |
18 | ENTRY(clear_page_c_e) |
| 19 | CFI_STARTPROC | |
| 20 | movl $4096,%ecx | |
| 21 | xorl %eax,%eax | |
| 22 | rep stosb | |
| 23 | ret | |
| 24 | CFI_ENDPROC | |
| 25 | ENDPROC(clear_page_c_e) | |
| 26 | ||
| 8d379dad JB |
27 | ENTRY(clear_page) |
| 28 | CFI_STARTPROC | |
| 7bcd3f34 AK |
29 | xorl %eax,%eax |
| 30 | movl $4096/64,%ecx | |
| 31 | .p2align 4 | |
| 32 | .Lloop: | |
| 33 | decl %ecx | |
| 34 | #define PUT(x) movq %rax,x*8(%rdi) | |
| 35 | movq %rax,(%rdi) | |
| 36 | PUT(1) | |
| 37 | PUT(2) | |
| 38 | PUT(3) | |
| 39 | PUT(4) | |
| 40 | PUT(5) | |
| 41 | PUT(6) | |
| 42 | PUT(7) | |
| 43 | leaq 64(%rdi),%rdi | |
| 44 | jnz .Lloop | |
| 45 | nop | |
| 46 | ret | |
| 8d379dad JB |
47 | CFI_ENDPROC |
| 48 | .Lclear_page_end: | |
| 49 | ENDPROC(clear_page) | |
| 7bcd3f34 | 50 | |
| e365c9df FY |
51 | /* |
| 52 | * Some CPUs support enhanced REP MOVSB/STOSB instructions. | |
| 53 | * It is recommended to use this when possible. | |
| 54 | * If enhanced REP MOVSB/STOSB is not available, try to use fast string. | |
| 55 | * Otherwise, use original function. | |
| 56 | * | |
| 57 | */ | |
| 7bcd3f34 | 58 | |
| e12edd02 | 59 | #include <asm/cpufeatures.h> |
| 7bcd3f34 | 60 | |
| 8d379dad JB |
61 | .section .altinstr_replacement,"ax" |
| 62 | 1: .byte 0xeb /* jmp <disp8> */ | |
| 63 | .byte (clear_page_c - clear_page) - (2f - 1b) /* offset */ | |
| e365c9df FY |
64 | 2: .byte 0xeb /* jmp <disp8> */ |
| 65 | .byte (clear_page_c_e - clear_page) - (3f - 2b) /* offset */ | |
| 66 | 3: | |
| 8d379dad | 67 | .previous |
| 7bcd3f34 | 68 | .section .altinstructions,"a" |
| e365c9df | 69 | altinstruction_entry clear_page,1b,X86_FEATURE_REP_GOOD,\ |
| 005db1f8 | 70 | .Lclear_page_end-clear_page, 2b-1b, 0 |
| e365c9df | 71 | altinstruction_entry clear_page,2b,X86_FEATURE_ERMS, \ |
| 005db1f8 | 72 | .Lclear_page_end-clear_page,3b-2b, 0 |
| 7bcd3f34 | 73 | .previous |