mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 04:34:11 +08:00
daf52375c1
... and fold handling of misaligned case into it. Implementation note: we stash the "will we need to rol8 the sum in the end" flag into the MSB of %rcx (the lower 32 bits are used for length); the rest is pretty straightforward. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
257 lines
4.2 KiB
ArmAsm
257 lines
4.2 KiB
ArmAsm
/*
|
|
* 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)
|