diff options
Diffstat (limited to 'arch/x86/lib/csum-copy_64.S')
| -rw-r--r-- | arch/x86/lib/csum-copy_64.S | 140 |
1 files changed, 84 insertions, 56 deletions
diff --git a/arch/x86/lib/csum-copy_64.S b/arch/x86/lib/csum-copy_64.S index 3394a8ff7fd0..1fbd8ee9642d 100644 --- a/arch/x86/lib/csum-copy_64.S +++ b/arch/x86/lib/csum-copy_64.S @@ -18,9 +18,6 @@ * 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. @@ -31,44 +28,32 @@ .macro source 10: - _ASM_EXTABLE_UA(10b, .Lbad_source) + _ASM_EXTABLE_UA(10b, .Lfault) .endm .macro dest 20: - _ASM_EXTABLE_UA(20b, .Lbad_dest) + _ASM_EXTABLE_UA(20b, .Lfault) .endm - /* - * No _ASM_EXTABLE_UA; this is used for intentional prefetch on a - * potentially unmapped kernel address. - */ - .macro ignore L=.Lignore -30: - _ASM_EXTABLE(30b, \L) - .endm - - SYM_FUNC_START(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) + 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) - movq %r8, (%rsp) - movq %r9, 1*8(%rsp) - - movl %ecx, %eax + movl $-1, %eax + xorl %r9d, %r9d movl %edx, %ecx + cmpl $8, %ecx + jb .Lshort - xorl %r9d, %r9d - movq %rcx, %r12 + testb $7, %sil + jne .Lunaligned +.Laligned: + movl %ecx, %r12d shrq $6, %r12 jz .Lhandle_tail /* < 64 */ @@ -99,7 +84,12 @@ SYM_FUNC_START(csum_partial_copy_generic) source movq 56(%rdi), %r13 - ignore 2f +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 @@ -131,8 +121,6 @@ SYM_FUNC_START(csum_partial_copy_generic) dest movq %r13, 56(%rsi) -3: - leaq 64(%rdi), %rdi leaq 64(%rsi), %rsi @@ -142,8 +130,8 @@ SYM_FUNC_START(csum_partial_copy_generic) /* do last up to 56 bytes */ .Lhandle_tail: - /* ecx: count */ - movl %ecx, %r10d + /* ecx: count, rcx.63: the end result needs to be rol8 */ + movq %rcx, %r10 andl $63, %ecx shrl $3, %ecx jz .Lfold @@ -172,6 +160,7 @@ SYM_FUNC_START(csum_partial_copy_generic) .Lhandle_7: movl %r10d, %ecx andl $7, %ecx +.L1: /* .Lshort rejoins the common path here */ shrl $1, %ecx jz .Lhandle_1 movl $2, %edx @@ -203,26 +192,65 @@ SYM_FUNC_START(csum_partial_copy_generic) 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 + 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 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 + /* Exception: just return 0 */ +.Lfault: + xorl %eax, %eax + jmp .Lout SYM_FUNC_END(csum_partial_copy_generic) |