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| /*
| * 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)
| * ecx sum (32bit)
| * r8 src_err_ptr (int)
| * r9 dst_err_ptr (int)
| *
| * 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(10b, .Lbad_source)
| .endm
|
| .macro dest
| 20:
| _ASM_EXTABLE(20b, .Lbad_dest)
| .endm
|
| .macro ignore L=.Lignore
| 30:
| _ASM_EXTABLE(30b, \L)
| .endm
|
|
| ENTRY(csum_partial_copy_generic)
| cmpl $3*64, %edx
| jle .Lignore
|
| .Lignore:
| subq $7*8, %rsp
| movq %rbx, 2*8(%rsp)
| movq %r12, 3*8(%rsp)
| movq %r14, 4*8(%rsp)
| movq %r13, 5*8(%rsp)
| movq %r15, 6*8(%rsp)
|
| movq %r8, (%rsp)
| movq %r9, 1*8(%rsp)
|
| movl %ecx, %eax
| movl %edx, %ecx
|
| xorl %r9d, %r9d
| movq %rcx, %r12
|
| 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
|
| ignore 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)
|
| 3:
|
| leaq 64(%rdi), %rdi
| leaq 64(%rsi), %rsi
|
| jnz .Lloop
|
| adcq %r9, %rax
|
| /* do last up to 56 bytes */
| .Lhandle_tail:
| /* ecx: count */
| movl %ecx, %r10d
| 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
| 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:
| movq 2*8(%rsp), %rbx
| movq 3*8(%rsp), %r12
| movq 4*8(%rsp), %r14
| movq 5*8(%rsp), %r13
| movq 6*8(%rsp), %r15
| addq $7*8, %rsp
| ret
|
| /* Exception handlers. Very simple, zeroing is done in the wrappers */
| .Lbad_source:
| movq (%rsp), %rax
| testq %rax, %rax
| jz .Lende
| movl $-EFAULT, (%rax)
| jmp .Lende
|
| .Lbad_dest:
| movq 8(%rsp), %rax
| testq %rax, %rax
| jz .Lende
| movl $-EFAULT, (%rax)
| jmp .Lende
| ENDPROC(csum_partial_copy_generic)
|
|
