diff options
| -rw-r--r-- | arch/x86/include/asm/uaccess_64.h | 2 | ||||
| -rw-r--r-- | arch/x86/lib/copy_user_64.S | 57 |
2 files changed, 14 insertions, 45 deletions
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h index 81b826d3b753..f2c02e4469cc 100644 --- a/arch/x86/include/asm/uaccess_64.h +++ b/arch/x86/include/asm/uaccess_64.h @@ -116,7 +116,7 @@ copy_user_generic(void *to, const void *from, unsigned long len) "2:\n" _ASM_EXTABLE_UA(1b, 2b) :"+c" (len), "+D" (to), "+S" (from), ASM_CALL_CONSTRAINT - : : "memory", "rax", "r8", "r9", "r10", "r11"); + : : "memory", "rax"); clac(); return len; } diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index 01c5de4c279b..0a81aafed7f8 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -27,7 +27,7 @@ * NOTE! The calling convention is very intentionally the same as * for 'rep movs', so that we can rewrite the function call with * just a plain 'rep movs' on machines that have FSRM. But to make - * it simpler for us, we can clobber rsi/rdi and rax/r8-r11 freely. + * it simpler for us, we can clobber rsi/rdi and rax freely. */ SYM_FUNC_START(rep_movs_alternative) cmpq $64,%rcx @@ -68,55 +68,24 @@ SYM_FUNC_START(rep_movs_alternative) _ASM_EXTABLE_UA( 3b, .Lcopy_user_tail) .Llarge: -0: ALTERNATIVE "jmp .Lunrolled", "rep movsb", X86_FEATURE_ERMS +0: ALTERNATIVE "jmp .Llarge_movsq", "rep movsb", X86_FEATURE_ERMS 1: RET - _ASM_EXTABLE_UA( 0b, 1b) + _ASM_EXTABLE_UA( 0b, 1b) - .p2align 4 -.Lunrolled: -10: movq (%rsi),%r8 -11: movq 8(%rsi),%r9 -12: movq 16(%rsi),%r10 -13: movq 24(%rsi),%r11 -14: movq %r8,(%rdi) -15: movq %r9,8(%rdi) -16: movq %r10,16(%rdi) -17: movq %r11,24(%rdi) -20: movq 32(%rsi),%r8 -21: movq 40(%rsi),%r9 -22: movq 48(%rsi),%r10 -23: movq 56(%rsi),%r11 -24: movq %r8,32(%rdi) -25: movq %r9,40(%rdi) -26: movq %r10,48(%rdi) -27: movq %r11,56(%rdi) - addq $64,%rsi - addq $64,%rdi - subq $64,%rcx - cmpq $64,%rcx - jae .Lunrolled - cmpl $8,%ecx - jae .Lword +.Llarge_movsq: + movq %rcx,%rax + shrq $3,%rcx + andl $7,%eax +0: rep movsq + movl %eax,%ecx testl %ecx,%ecx jne .Lcopy_user_tail RET - _ASM_EXTABLE_UA(10b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(11b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(12b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(13b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(14b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(15b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(16b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(17b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(20b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(21b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(22b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(23b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(24b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(25b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(26b, .Lcopy_user_tail) - _ASM_EXTABLE_UA(27b, .Lcopy_user_tail) +1: leaq (%rax,%rcx,8),%rcx + jmp .Lcopy_user_tail + + _ASM_EXTABLE_UA( 0b, 1b) SYM_FUNC_END(rep_movs_alternative) EXPORT_SYMBOL(rep_movs_alternative) |