| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 1 | #include <linux/linkage.h> |
| Borislav Petkov | cd4d09e | 2016-01-26 22:12:04 +0100 | [diff] [blame] | 2 | #include <asm/cpufeatures.h> |
| Fenghua Yu | e365c9d | 2011-05-17 15:29:14 -0700 | [diff] [blame] | 3 | #include <asm/alternative-asm.h> |
| Al Viro | 784d569 | 2016-01-11 11:04:34 -0500 | [diff] [blame] | 4 | #include <asm/export.h> |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 5 | |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | /* |
| Borislav Petkov | 6620ef2 | 2015-01-18 12:57:41 +0100 | [diff] [blame] | 7 | * Most CPUs support enhanced REP MOVSB/STOSB instructions. It is |
| 8 | * recommended to use this when possible and we do use them by default. |
| 9 | * If enhanced REP MOVSB/STOSB is not available, try to use fast string. |
| 10 | * Otherwise, use original. |
| 11 | */ |
| 12 | |
| 13 | /* |
| 14 | * Zero a page. |
| 15 | * %rdi - page |
| 16 | */ |
| Borislav Petkov | f25d384 | 2017-02-09 01:34:49 +0100 | [diff] [blame] | 17 | ENTRY(clear_page_rep) |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 18 | movl $4096/8,%ecx |
| 19 | xorl %eax,%eax |
| 20 | rep stosq |
| 21 | ret |
| Borislav Petkov | f25d384 | 2017-02-09 01:34:49 +0100 | [diff] [blame] | 22 | ENDPROC(clear_page_rep) |
| 23 | EXPORT_SYMBOL_GPL(clear_page_rep) |
| Jan Beulich | 8d379da | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 24 | |
| Borislav Petkov | 6620ef2 | 2015-01-18 12:57:41 +0100 | [diff] [blame] | 25 | ENTRY(clear_page_orig) |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 26 | xorl %eax,%eax |
| 27 | movl $4096/64,%ecx |
| 28 | .p2align 4 |
| 29 | .Lloop: |
| 30 | decl %ecx |
| 31 | #define PUT(x) movq %rax,x*8(%rdi) |
| 32 | movq %rax,(%rdi) |
| 33 | PUT(1) |
| 34 | PUT(2) |
| 35 | PUT(3) |
| 36 | PUT(4) |
| 37 | PUT(5) |
| 38 | PUT(6) |
| 39 | PUT(7) |
| 40 | leaq 64(%rdi),%rdi |
| 41 | jnz .Lloop |
| 42 | nop |
| 43 | ret |
| Borislav Petkov | 6620ef2 | 2015-01-18 12:57:41 +0100 | [diff] [blame] | 44 | ENDPROC(clear_page_orig) |
| Borislav Petkov | f25d384 | 2017-02-09 01:34:49 +0100 | [diff] [blame] | 45 | EXPORT_SYMBOL_GPL(clear_page_orig) |
| Andi Kleen | 7bcd3f3 | 2006-02-03 21:51:02 +0100 | [diff] [blame] | 46 | |
| Borislav Petkov | f25d384 | 2017-02-09 01:34:49 +0100 | [diff] [blame] | 47 | ENTRY(clear_page_erms) |
| Borislav Petkov | 6620ef2 | 2015-01-18 12:57:41 +0100 | [diff] [blame] | 48 | movl $4096,%ecx |
| 49 | xorl %eax,%eax |
| 50 | rep stosb |
| 51 | ret |
| Borislav Petkov | f25d384 | 2017-02-09 01:34:49 +0100 | [diff] [blame] | 52 | ENDPROC(clear_page_erms) |
| 53 | EXPORT_SYMBOL_GPL(clear_page_erms) |
