diff options
Diffstat (limited to 'arch/x86_64/lib/csum-copy.S')
| -rw-r--r-- | arch/x86_64/lib/csum-copy.S | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/arch/x86_64/lib/csum-copy.S b/arch/x86_64/lib/csum-copy.S new file mode 100644 index 00000000000..01808ec3783 --- /dev/null +++ b/arch/x86_64/lib/csum-copy.S @@ -0,0 +1,233 @@ +/* + * 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> + +/* + * 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: + .section __ex_table,"a" + .align 8 + .quad 10b,.Lbad_source + .previous + .endm + + .macro dest +20: + .section __ex_table,"a" + .align 8 + .quad 20b,.Lbad_dest + .previous + .endm + + .macro ignore L=.Lignore +30: + .section __ex_table,"a" + .align 8 + .quad 30b,\L + .previous + .endm + + + .globl csum_partial_copy_generic + .p2align 4 +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 %rbp,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, rbp: 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),%rbp + 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 %rbp,%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 %rbp,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 upto 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 upto 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 + dest + decl %ecx + 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: + testl $1,%r10d + 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),%rbp + 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 |