diff options
Diffstat (limited to 'arch/x86/lib/copy_user_nocache_64.S')
| -rw-r--r-- | arch/x86/lib/copy_user_nocache_64.S | 283 |
1 files changed, 103 insertions, 180 deletions
diff --git a/arch/x86/lib/copy_user_nocache_64.S b/arch/x86/lib/copy_user_nocache_64.S index 9d3d1ab83763..40e0e309d27e 100644 --- a/arch/x86/lib/copy_user_nocache_64.S +++ b/arch/x86/lib/copy_user_nocache_64.S @@ -1,4 +1,6 @@ -/* Copyright 2002 Andi Kleen, SuSE Labs. +/* + * Copyright 2008 Vitaly Mayatskikh <vmayatsk@redhat.com> + * Copyright 2002 Andi Kleen, SuSE Labs. * Subject to the GNU Public License v2. * * Functions to copy from and to user space. @@ -12,204 +14,125 @@ #include <asm/current.h> #include <asm/asm-offsets.h> #include <asm/thread_info.h> -#include <asm/cpufeature.h> - -/* - * copy_user_nocache - Uncached memory copy with exception handling - * This will force destination/source out of cache for more performance. - * - * Input: - * rdi destination - * rsi source - * rdx count - * rcx zero flag when 1 zero on exception - * - * Output: - * eax uncopied bytes or 0 if successful. - */ -ENTRY(__copy_user_nocache) - CFI_STARTPROC - pushq %rbx - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rbx, 0 - pushq %rcx /* save zero flag */ - CFI_ADJUST_CFA_OFFSET 8 - CFI_REL_OFFSET rcx, 0 - - xorl %eax,%eax /* zero for the exception handler */ + .macro ALIGN_DESTINATION #ifdef FIX_ALIGNMENT /* check for bad alignment of destination */ movl %edi,%ecx andl $7,%ecx - jnz .Lbad_alignment -.Lafter_bad_alignment: -#endif - - movq %rdx,%rcx - - movl $64,%ebx - shrq $6,%rdx - decq %rdx - js .Lhandle_tail - - .p2align 4 -.Lloop: -.Ls1: movq (%rsi),%r11 -.Ls2: movq 1*8(%rsi),%r8 -.Ls3: movq 2*8(%rsi),%r9 -.Ls4: movq 3*8(%rsi),%r10 -.Ld1: movnti %r11,(%rdi) -.Ld2: movnti %r8,1*8(%rdi) -.Ld3: movnti %r9,2*8(%rdi) -.Ld4: movnti %r10,3*8(%rdi) - -.Ls5: movq 4*8(%rsi),%r11 -.Ls6: movq 5*8(%rsi),%r8 -.Ls7: movq 6*8(%rsi),%r9 -.Ls8: movq 7*8(%rsi),%r10 -.Ld5: movnti %r11,4*8(%rdi) -.Ld6: movnti %r8,5*8(%rdi) -.Ld7: movnti %r9,6*8(%rdi) -.Ld8: movnti %r10,7*8(%rdi) + jz 102f /* already aligned */ + subl $8,%ecx + negl %ecx + subl %ecx,%edx +100: movb (%rsi),%al +101: movb %al,(%rdi) + incq %rsi + incq %rdi + decl %ecx + jnz 100b +102: + .section .fixup,"ax" +103: addl %r8d,%edx /* ecx is zerorest also */ + jmp copy_user_handle_tail + .previous - dec %rdx + .section __ex_table,"a" + .align 8 + .quad 100b,103b + .quad 101b,103b + .previous +#endif + .endm +/* + * copy_user_nocache - Uncached memory copy with exception handling + * This will force destination/source out of cache for more performance. + */ +ENTRY(__copy_user_nocache) + CFI_STARTPROC + cmpl $8,%edx + jb 20f /* less then 8 bytes, go to byte copy loop */ + ALIGN_DESTINATION + movl %edx,%ecx + andl $63,%edx + shrl $6,%ecx + jz 17f +1: movq (%rsi),%r8 +2: movq 1*8(%rsi),%r9 +3: movq 2*8(%rsi),%r10 +4: movq 3*8(%rsi),%r11 +5: movnti %r8,(%rdi) +6: movnti %r9,1*8(%rdi) +7: movnti %r10,2*8(%rdi) +8: movnti %r11,3*8(%rdi) +9: movq 4*8(%rsi),%r8 +10: movq 5*8(%rsi),%r9 +11: movq 6*8(%rsi),%r10 +12: movq 7*8(%rsi),%r11 +13: movnti %r8,4*8(%rdi) +14: movnti %r9,5*8(%rdi) +15: movnti %r10,6*8(%rdi) +16: movnti %r11,7*8(%rdi) leaq 64(%rsi),%rsi leaq 64(%rdi),%rdi - - jns .Lloop - - .p2align 4 -.Lhandle_tail: - movl %ecx,%edx - andl $63,%ecx - shrl $3,%ecx - jz .Lhandle_7 - movl $8,%ebx - .p2align 4 -.Lloop_8: -.Ls9: movq (%rsi),%r8 -.Ld9: movnti %r8,(%rdi) decl %ecx - leaq 8(%rdi),%rdi + jnz 1b +17: movl %edx,%ecx + andl $7,%edx + shrl $3,%ecx + jz 20f +18: movq (%rsi),%r8 +19: movnti %r8,(%rdi) leaq 8(%rsi),%rsi - jnz .Lloop_8 - -.Lhandle_7: + leaq 8(%rdi),%rdi + decl %ecx + jnz 18b +20: andl %edx,%edx + jz 23f movl %edx,%ecx - andl $7,%ecx - jz .Lende - .p2align 4 -.Lloop_1: -.Ls10: movb (%rsi),%bl -.Ld10: movb %bl,(%rdi) - incq %rdi +21: movb (%rsi),%al +22: movb %al,(%rdi) incq %rsi + incq %rdi decl %ecx - jnz .Lloop_1 - - CFI_REMEMBER_STATE -.Lende: - popq %rcx - CFI_ADJUST_CFA_OFFSET -8 - CFI_RESTORE %rcx - popq %rbx - CFI_ADJUST_CFA_OFFSET -8 - CFI_RESTORE rbx + jnz 21b +23: xorl %eax,%eax sfence ret - CFI_RESTORE_STATE -#ifdef FIX_ALIGNMENT - /* align destination */ - .p2align 4 -.Lbad_alignment: - movl $8,%r9d - subl %ecx,%r9d - movl %r9d,%ecx - cmpq %r9,%rdx - jz .Lhandle_7 - js .Lhandle_7 -.Lalign_1: -.Ls11: movb (%rsi),%bl -.Ld11: movb %bl,(%rdi) - incq %rsi - incq %rdi - decl %ecx - jnz .Lalign_1 - subq %r9,%rdx - jmp .Lafter_bad_alignment -#endif + .section .fixup,"ax" +30: shll $6,%ecx + addl %ecx,%edx + jmp 60f +40: lea (%rdx,%rcx,8),%rdx + jmp 60f +50: movl %ecx,%edx +60: sfence + movl %r8d,%ecx + jmp copy_user_handle_tail + .previous - /* table sorted by exception address */ .section __ex_table,"a" - .align 8 - .quad .Ls1,.Ls1e /* .Ls[1-4] - 0 bytes copied */ - .quad .Ls2,.Ls1e - .quad .Ls3,.Ls1e - .quad .Ls4,.Ls1e - .quad .Ld1,.Ls1e /* .Ld[1-4] - 0..24 bytes coped */ - .quad .Ld2,.Ls2e - .quad .Ld3,.Ls3e - .quad .Ld4,.Ls4e - .quad .Ls5,.Ls5e /* .Ls[5-8] - 32 bytes copied */ - .quad .Ls6,.Ls5e - .quad .Ls7,.Ls5e - .quad .Ls8,.Ls5e - .quad .Ld5,.Ls5e /* .Ld[5-8] - 32..56 bytes copied */ - .quad .Ld6,.Ls6e - .quad .Ld7,.Ls7e - .quad .Ld8,.Ls8e - .quad .Ls9,.Le_quad - .quad .Ld9,.Le_quad - .quad .Ls10,.Le_byte - .quad .Ld10,.Le_byte -#ifdef FIX_ALIGNMENT - .quad .Ls11,.Lzero_rest - .quad .Ld11,.Lzero_rest -#endif - .quad .Le5,.Le_zero + .quad 1b,30b + .quad 2b,30b + .quad 3b,30b + .quad 4b,30b + .quad 5b,30b + .quad 6b,30b + .quad 7b,30b + .quad 8b,30b + .quad 9b,30b + .quad 10b,30b + .quad 11b,30b + .quad 12b,30b + .quad 13b,30b + .quad 14b,30b + .quad 15b,30b + .quad 16b,30b + .quad 18b,40b + .quad 19b,40b + .quad 21b,50b + .quad 22b,50b .previous - - /* eax: zero, ebx: 64 */ -.Ls1e: addl $8,%eax /* eax: bytes left uncopied: Ls1e: 64 .. Ls8e: 8 */ -.Ls2e: addl $8,%eax -.Ls3e: addl $8,%eax -.Ls4e: addl $8,%eax -.Ls5e: addl $8,%eax -.Ls6e: addl $8,%eax -.Ls7e: addl $8,%eax -.Ls8e: addl $8,%eax - addq %rbx,%rdi /* +64 */ - subq %rax,%rdi /* correct destination with computed offset */ - - shlq $6,%rdx /* loop counter * 64 (stride length) */ - addq %rax,%rdx /* add offset to loopcnt */ - andl $63,%ecx /* remaining bytes */ - addq %rcx,%rdx /* add them */ - jmp .Lzero_rest - - /* exception on quad word loop in tail handling */ - /* ecx: loopcnt/8, %edx: length, rdi: correct */ -.Le_quad: - shll $3,%ecx - andl $7,%edx - addl %ecx,%edx - /* edx: bytes to zero, rdi: dest, eax:zero */ -.Lzero_rest: - cmpl $0,(%rsp) /* zero flag set? */ - jz .Le_zero - movq %rdx,%rcx -.Le_byte: - xorl %eax,%eax -.Le5: rep - stosb - /* when there is another exception while zeroing the rest just return */ -.Le_zero: - movq %rdx,%rax - jmp .Lende CFI_ENDPROC ENDPROC(__copy_user_nocache) - - |