diff options
Diffstat (limited to 'arch/x86/lib/csum-copy_64.S')
| -rw-r--r-- | arch/x86/lib/csum-copy_64.S | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/arch/x86/lib/csum-copy_64.S b/arch/x86/lib/csum-copy_64.S new file mode 100644 index 000000000..d9e16a2cf --- /dev/null +++ b/arch/x86/lib/csum-copy_64.S @@ -0,0 +1,256 @@ +/* + * Copyright 2002, 2003 Andi Kleen, SuSE Labs. + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. No warranty for anything given at all. + */ +#include <linux/linkage.h> +#include <asm/errno.h> +#include <asm/asm.h> + +/* + * Checksum copy with exception handling. + * On exceptions src_err_ptr or dst_err_ptr is set to -EFAULT and the + * destination is zeroed. + * + * Input + * rdi source + * rsi destination + * edx len (32bit) + * + * Output + * eax 64bit sum. undefined in case of exception. + * + * Wrappers need to take care of valid exception sum and zeroing. + * They also should align source or destination to 8 bytes. + */ + + .macro source +10: + _ASM_EXTABLE_UA(10b, .Lfault) + .endm + + .macro dest +20: + _ASM_EXTABLE_UA(20b, .Lfault) + .endm + +SYM_FUNC_START(csum_partial_copy_generic) + subq $5*8, %rsp + movq %rbx, 0*8(%rsp) + movq %r12, 1*8(%rsp) + movq %r14, 2*8(%rsp) + movq %r13, 3*8(%rsp) + movq %r15, 4*8(%rsp) + + movl $-1, %eax + xorl %r9d, %r9d + movl %edx, %ecx + cmpl $8, %ecx + jb .Lshort + + testb $7, %sil + jne .Lunaligned +.Laligned: + movl %ecx, %r12d + + shrq $6, %r12 + jz .Lhandle_tail /* < 64 */ + + clc + + /* main loop. clear in 64 byte blocks */ + /* r9: zero, r8: temp2, rbx: temp1, rax: sum, rcx: saved length */ + /* r11: temp3, rdx: temp4, r12 loopcnt */ + /* r10: temp5, r15: temp6, r14 temp7, r13 temp8 */ + .p2align 4 +.Lloop: + source + movq (%rdi), %rbx + source + movq 8(%rdi), %r8 + source + movq 16(%rdi), %r11 + source + movq 24(%rdi), %rdx + + source + movq 32(%rdi), %r10 + source + movq 40(%rdi), %r15 + source + movq 48(%rdi), %r14 + source + movq 56(%rdi), %r13 + +30: + /* + * No _ASM_EXTABLE_UA; this is used for intentional prefetch on a + * potentially unmapped kernel address. + */ + _ASM_EXTABLE(30b, 2f) + prefetcht0 5*64(%rdi) +2: + adcq %rbx, %rax + adcq %r8, %rax + adcq %r11, %rax + adcq %rdx, %rax + adcq %r10, %rax + adcq %r15, %rax + adcq %r14, %rax + adcq %r13, %rax + + decl %r12d + + dest + movq %rbx, (%rsi) + dest + movq %r8, 8(%rsi) + dest + movq %r11, 16(%rsi) + dest + movq %rdx, 24(%rsi) + + dest + movq %r10, 32(%rsi) + dest + movq %r15, 40(%rsi) + dest + movq %r14, 48(%rsi) + dest + movq %r13, 56(%rsi) + + leaq 64(%rdi), %rdi + leaq 64(%rsi), %rsi + + jnz .Lloop + + adcq %r9, %rax + + /* do last up to 56 bytes */ +.Lhandle_tail: + /* ecx: count, rcx.63: the end result needs to be rol8 */ + movq %rcx, %r10 + andl $63, %ecx + shrl $3, %ecx + jz .Lfold + clc + .p2align 4 +.Lloop_8: + source + movq (%rdi), %rbx + adcq %rbx, %rax + decl %ecx + dest + movq %rbx, (%rsi) + leaq 8(%rsi), %rsi /* preserve carry */ + leaq 8(%rdi), %rdi + jnz .Lloop_8 + adcq %r9, %rax /* add in carry */ + +.Lfold: + /* reduce checksum to 32bits */ + movl %eax, %ebx + shrq $32, %rax + addl %ebx, %eax + adcl %r9d, %eax + + /* do last up to 6 bytes */ +.Lhandle_7: + movl %r10d, %ecx + andl $7, %ecx +.L1: /* .Lshort rejoins the common path here */ + shrl $1, %ecx + jz .Lhandle_1 + movl $2, %edx + xorl %ebx, %ebx + clc + .p2align 4 +.Lloop_1: + source + movw (%rdi), %bx + adcl %ebx, %eax + decl %ecx + dest + movw %bx, (%rsi) + leaq 2(%rdi), %rdi + leaq 2(%rsi), %rsi + jnz .Lloop_1 + adcl %r9d, %eax /* add in carry */ + + /* handle last odd byte */ +.Lhandle_1: + testb $1, %r10b + jz .Lende + xorl %ebx, %ebx + source + movb (%rdi), %bl + dest + movb %bl, (%rsi) + addl %ebx, %eax + adcl %r9d, %eax /* carry */ + +.Lende: + testq %r10, %r10 + js .Lwas_odd +.Lout: + movq 0*8(%rsp), %rbx + movq 1*8(%rsp), %r12 + movq 2*8(%rsp), %r14 + movq 3*8(%rsp), %r13 + movq 4*8(%rsp), %r15 + addq $5*8, %rsp + RET +.Lshort: + movl %ecx, %r10d + jmp .L1 +.Lunaligned: + xorl %ebx, %ebx + testb $1, %sil + jne .Lodd +1: testb $2, %sil + je 2f + source + movw (%rdi), %bx + dest + movw %bx, (%rsi) + leaq 2(%rdi), %rdi + subq $2, %rcx + leaq 2(%rsi), %rsi + addq %rbx, %rax +2: testb $4, %sil + je .Laligned + source + movl (%rdi), %ebx + dest + movl %ebx, (%rsi) + leaq 4(%rdi), %rdi + subq $4, %rcx + leaq 4(%rsi), %rsi + addq %rbx, %rax + jmp .Laligned + +.Lodd: + source + movb (%rdi), %bl + dest + movb %bl, (%rsi) + leaq 1(%rdi), %rdi + leaq 1(%rsi), %rsi + /* decrement, set MSB */ + leaq -1(%rcx, %rcx), %rcx + rorq $1, %rcx + shll $8, %ebx + addq %rbx, %rax + jmp 1b + +.Lwas_odd: + roll $8, %eax + jmp .Lout + + /* Exception: just return 0 */ +.Lfault: + xorl %eax, %eax + jmp .Lout +SYM_FUNC_END(csum_partial_copy_generic) |