/* SPDX-License-Identifier: GPL-2.0 */
/* checksum.S: Sparc optimized checksum code.
*
* Copyright(C) 1995 Linus Torvalds
* Copyright(C) 1995 Miguel de Icaza
* Copyright(C) 1996 David S. Miller
* Copyright(C) 1997 Jakub Jelinek
*
* derived from:
* Linux/Alpha checksum c-code
* Linux/ix86 inline checksum assembly
* RFC1071 Computing the Internet Checksum (esp. Jacobsons m68k code)
* David Mosberger-Tang for optimized reference c-code
* BSD4.4 portable checksum routine
*/
#include <linux/export.h>
#include <asm/errno.h>
#define CSUM_BIGCHUNK(buf, offset, sum, t0, t1, t2, t3, t4, t5) \
ldd [buf + offset + 0x00], t0; \
ldd [buf + offset + 0x08], t2; \
addxcc t0, sum, sum; \
addxcc t1, sum, sum; \
ldd [buf + offset + 0x10], t4; \
addxcc t2, sum, sum; \
addxcc t3, sum, sum; \
ldd [buf + offset + 0x18], t0; \
addxcc t4, sum, sum; \
addxcc t5, sum, sum; \
addxcc t0, sum, sum; \
addxcc t1, sum, sum;
#define CSUM_LASTCHUNK(buf, offset, sum, t0, t1, t2, t3) \
ldd [buf - offset - 0x08], t0; \
ldd [buf - offset - 0x00], t2; \
addxcc t0, sum, sum; \
addxcc t1, sum, sum; \
addxcc t2, sum, sum; \
addxcc t3, sum, sum;
/* Do end cruft out of band to get better cache patterns. */
csum_partial_end_cruft:
be 1f ! caller asks %o1 & 0x8
andcc %o1, 4, %g0 ! nope, check for word remaining
ldd [%o0], %g2 ! load two
addcc %g2, %o2, %o2 ! add first word to sum
addxcc %g3, %o2, %o2 ! add second word as well
add %o0, 8, %o0 ! advance buf ptr
addx %g0, %o2, %o2 ! add in final carry
andcc %o1, 4, %g0 ! check again for word remaining
1: be 1f ! nope, skip this code
andcc %o1, 3, %o1 ! check for trailing bytes
ld [%o0], %g2 ! load it
addcc %g2, %o2, %o2 ! add to sum
add %o0, 4, %o0 ! advance buf ptr
addx %g0, %o2, %o2 ! add in final carry
andcc %o1, 3, %g0 ! check again for trailing bytes
1: be 1f ! no trailing bytes, return
addcc %o1, -1, %g0 ! only one byte remains?
bne 2f ! at least two bytes more
subcc %o1, 2, %o1 ! only two bytes more?
b 4f ! only one byte remains
or %g0, %g0, %o4 ! clear fake hword value
2: lduh [%o0], %o4 ! get hword
be 6f ! jmp if only hword remains
add %o0, 2, %o0 ! advance buf ptr either way
sll %o4, 16, %o4 ! create upper hword
4: ldub [%o0], %o5 ! get final byte
sll %o5, 8, %o5 ! put into place
or %o5, %o4, %o4 ! coalese with hword (if any)
6: addcc %o4, %o2, %o2 ! add to sum
1: retl ! get outta here
addx %g0, %o2, %o0 ! add final carry into retval
/* Also do alignment out of band to get better cache patterns. */
csum_partial_fix_alignment:
cmp %o1, 6
bl cpte - 0x4
andcc %o0, 0x2, %g0
be 1f
andcc %o0, 0x4, %g0
lduh [%o0 + 0x00], %g2
sub %o1, 2, %o1
add %o0, 2, %o0
sll %g2, 16, %g2
addcc %g2, %o2, %o2
srl %o2, 16, %g3
addx %g0, %g3, %g2
sll %o2, 16, %o2
sll %g2, 16, %g3
srl %o2, 16, %o2
andcc %o0, 0x4, %g0
or %g3, %o2, %o2
1: be cpa
andcc %o1, 0xffffff80, %o3
ld [%o0 + 0x00], %g2
sub %o1, 4, %o1
addcc %g2, %o2, %o2
add %o0, 4, %o0
addx %g0, %o2, %o2
b cpa
andcc %o1, 0xffffff80, %o3
/* The common case is to get called with a nicely aligned
* buffer of size 0x20. Follow the code path for that case.
*/
.globl csum_partial
EXPORT_SYMBOL(csum_partial)
csum_partial: /* %o0=buf, %o1=len, %o2=sum */
andcc %o0, 0x7, %g0 ! alignment problems?
bne csum_partial_fix_alignment ! yep, handle it
sethi %hi(cpte - 8), %g7 ! prepare table jmp ptr
andcc %o1, 0xffffff80, %o3 ! num loop iterations
cpa: be 3f ! none to do
andcc %o1, 0x70, %g1 ! clears carry flag too
5: CSUM_BIGCHUNK(%o0, 0x00, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
CSUM_BIGCHUNK(%o0, 0x20, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
CSUM_BIGCHUNK(%o0, 0x40, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
CSUM_BIGCHUNK(%o0, 0x60, %o2, %o4, %o5, %g2, %g3, %g4, %g5)
addx %g0, %o2, %o2 ! sink in final carry
subcc %o3, 128, %o3 ! detract from loop iters
bne 5b ! more to do
add %o0, 128, %o0 ! advance buf ptr
andcc %o1, 0x70, %g1 ! clears carry flag too
3: be cpte ! nope
andcc %o1, 0xf, %g0 ! anything left at all?
srl %g1, 1, %o4 ! compute offset
sub %g7, %g1, %g7 ! adjust jmp ptr
sub %g7, %o4, %g7 ! final jmp ptr adjust
jmp %g7 + %lo(cpte - 8) ! enter the table
add %o0, %g1, %o0 ! advance buf ptr
cptbl: CSUM_LASTCHUNK(%o0, 0x68, %o2, %g2, %g3, %g4, %g5)
CSUM_LASTCHUNK(%o0, 0x58, %o2, %g2, %g3, %g4, %g5)
CSUM_LASTCHUNK(%o0, 0x48, %o2, %g2, %g3, %g4, %g5)
CSUM_LASTCHUNK(%o0, 0x38, %o2, %g2, %g3, %g4, %g5)
CSUM_LASTCHUNK(%o0, 0x28, %o2, %g2, %g3, %g4, %g5)
CSUM_LASTCHUNK(%o0, 0x18, %o2, %g2, %g3, %g4, %g5)
CSUM_LASTCHUNK(%o0, 0x08, %o2, %g2, %g3, %g4, %g5)
addx %g0, %o2, %o2 ! fetch final carry
andcc %o1, 0xf, %g0 ! anything left at all?
cpte: bne csum_partial_end_cruft ! yep, handle it
andcc %o1, 8, %g0 ! check how much
cpout: retl ! get outta here
mov %o2, %o0 ! return computed csum
/* Work around cpp -rob */
#define ALLOC #alloc
#define EXECINSTR #execinstr
#define EX(x,y) \
98: x,y; \
.section __ex_table,ALLOC; \
.align 4; \
.word 98b, cc_fault; \
.text; \
.align 4
/* This aligned version executes typically in 8.5 superscalar cycles, this
* is the best I can do. I say 8.5 because the final add will pair with
* the next ldd in the main unrolled loop. Thus the pipe is always full.
* If you change these macros (including order of instructions),
* please check the fixup code below as well.
*/
#define CSUMCOPY_BIGCHUNK_ALIGNED(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \
EX(ldd [src + off + 0x00], t0); \
EX(ldd [src + off + 0x08], t2); \
addxcc t0, sum, sum; \
EX(ldd [src + off + 0x10], t4); \
addxcc t1, sum, sum; \
EX(ldd [src + off + 0x18], t6); \
addxcc t2, sum, sum; \
EX(std t0, [dst + off + 0x00]); \
addxcc t3, sum, sum; \
EX(std t2, [dst + off + 0x08]); \
addxcc t4, sum, sum; \
EX(std t4, [dst + off + 0x10]); \
addxcc t5, sum, sum; \
EX(std t6, [dst + off + 0x18]); \
addxcc t6, sum, sum; \
addxcc t7, sum, sum;
/* 12 superscalar cycles seems to be the limit for this case,
* because of this we thus do all the ldd's together to get
* Viking MXCC into streaming mode. Ho hum...
*/
#define CSUMCOPY_BIGCHUNK(src, dst, sum, off, t0, t1, t2, t3, t4, t5, t6, t7) \
EX(ldd [src + off + 0x00], t0); \
EX(ldd [src + off + 0x08], t2); \
EX(ldd [src + off + 0x10], t4); \
EX(ldd [src + off + 0x18], t6); \
EX(st t0, [dst + off + 0x00]); \
addxcc t0, sum, sum; \
EX(st t1, [dst + off + 0x04]); \
addxcc t1, sum, sum; \
EX(st t2, [dst + off + 0x08]); \
addxcc t2, sum, sum; \
EX(st t3, [dst + off + 0x0c]); \
addxcc t3, sum, sum; \
EX(st t4, [dst + off + 0x10]); \
addxcc t4, sum, sum; \
EX(st t5, [dst + off + 0x14]); \
addxcc t5, sum, sum; \
EX(st t6, [dst + off + 0x18]); \
addxcc t6, sum, sum; \
EX(st t7, [dst + off + 0x1c]); \
addxcc t7, sum, sum;
/* Yuck, 6 superscalar cycles... */
#define CSUMCOPY_LASTCHUNK(src, dst, sum, off, t0, t1, t2, t3) \
EX(ldd [src - off - 0x08], t0); \
EX(ldd [src - off - 0x00], t2); \
addxcc t0, sum, sum; \
EX(st t0, [dst - off - 0x08]); \
addxcc t1, sum, sum; \
EX(st t1, [dst - off - 0x04]); \
addxcc t2, sum, sum; \
EX(st t2, [dst - off - 0x00]); \
addxcc t3, sum, sum; \
EX(st t3, [dst - off + 0x04]);
/* Handle the end cruft code out of band for better cache patterns. */
cc_end_cruft:
be 1f
andcc %o3, 4, %g0
EX(ldd [%o0 + 0x00], %g2)
add %o1, 8, %o1
addcc %g2, %g7, %g7
add %o0, 8, %o0
addxcc %g3, %g7, %g7
EX(st %g2, [%o1 - 0x08])
addx %g0, %g7, %g7
andcc %o3, 4, %g0
EX(st %g3, [%o1 - 0x04])
1: be 1f
andcc %o3, 3, %o3
EX(ld [%o0 + 0x00], %g2)
add %o1, 4, %o1
addcc %g2, %g7, %g7
EX(st %g2, [%o1 - 0x04])
addx %g0, %g7, %g7
andcc %o3, 3, %g0
add %o0, 4, %o0
1: be 1f
addcc %o3, -1, %g0
bne 2f
subcc %o3, 2, %o3
b 4f
or %g0, %g0, %o4
2: EX(lduh [%o0 + 0x00], %o4)
add %o0, 2, %o0
EX(sth %o4, [%o1 + 0x00])
be 6f
add %o1, 2, %o1
sll %o4, 16, %o4
4: EX(ldub [%o0 + 0x00], %o5)
EX(stb %o5, [%o1 + 0x00])
sll %o5, 8, %o5
or %o5, %o4, %o4
6: addcc %o4, %g7, %g7
1: retl
addx %g0, %g7, %o0
/* Also, handle the alignment code out of band. */
cc_dword_align:
cmp %g1, 16
bge 1f
srl %g1, 1, %o3
2: cmp %o3, 0
be,a ccte
andcc %g1, 0xf, %o3
andcc %o3, %o0, %g0 ! Check %o0 only (%o1 has the same last 2 bits)
be,a 2b
srl %o3, 1, %o3
1: andcc %o0, 0x1, %g0
bne ccslow
andcc %o0, 0x2, %g0
be 1f
andcc %o0, 0x4, %g0
EX(lduh [%o0 + 0x00], %g4)
sub %g1, 2, %g1
EX(sth %g4, [%o1 + 0x00])
add %o0, 2, %o0
sll %g4, 16, %g4
addcc %g4, %g7, %g7
add %o1, 2, %o1
srl %g7, 16, %g3
addx %g0, %g3, %g4
sll %g7, 16, %g7
sll %g4, 16, %g3
srl %g7, 16, %g7
andcc %o0, 0x4, %g0
or %g3, %g7, %g7
1: be 3f
andcc %g1, 0xffffff80, %g0
EX(ld [%o0 + 0x00], %g4)
sub %g1, 4, %g1
EX(st %g4, [%o1 + 0x00])
add %o0, 4, %o0
addcc %g4, %g7, %g7
add %o1, 4, %o1
addx %g0, %g7, %g7
b 3f
andcc %g1, 0xffffff80, %g0
/* Sun, you just can't beat me, you just can't. Stop trying,
* give up. I'm serious, I am going to kick the living shit
* out of you, game over, lights out.
*/
.align 8
.globl __csum_partial_copy_sparc_generic
EXPORT_SYMBOL(__csum_partial_copy_sparc_generic)
__csum_partial_copy_sparc_generic:
/* %o0=src, %o1=dest, %g1=len, %g7=sum */
xor %o0, %o1, %o4 ! get changing bits
andcc %o4, 3, %g0 ! check for mismatched alignment
bne ccslow ! better this than unaligned/fixups
andcc %o0, 7, %g0 ! need to align things?
bne cc_dword_align ! yes, we check for short lengths there
andcc %g1, 0xffffff80, %g0 ! can we use unrolled loop?
3: be 3f ! nope, less than one loop remains
andcc %o1, 4, %g0 ! dest aligned on 4 or 8 byte boundary?
be ccdbl + 4 ! 8 byte aligned, kick ass
5: CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
CSUMCOPY_BIGCHUNK(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
sub %g1, 128, %g1 ! detract from length
addx %g0, %g7, %g7 ! add in last carry bit
andcc %g1, 0xffffff80, %g0 ! more to csum?
add %o0, 128, %o0 ! advance src ptr
bne 5b ! we did not go negative, continue looping
add %o1, 128, %o1 ! advance dest ptr
3: andcc %g1, 0x70, %o2 ! can use table?
ccmerge:be ccte ! nope, go and check for end cruft
andcc %g1, 0xf, %o3 ! get low bits of length (clears carry btw)
srl %o2, 1, %o4 ! begin negative offset computation
sethi %hi(12f), %o5 ! set up table ptr end
add %o0, %o2, %o0 ! advance src ptr
sub %o5, %o4, %o5 ! continue table calculation
sll %o2, 1, %g2 ! constant multiplies are fun...
sub %o5, %g2, %o5 ! some more adjustments
jmp %o5 + %lo(12f) ! jump into it, duff style, wheee...
add %o1, %o2, %o1 ! advance dest ptr (carry is clear btw)
cctbl: CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x68,%g2,%g3,%g4,%g5)
CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x58,%g2,%g3,%g4,%g5)
CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x48,%g2,%g3,%g4,%g5)
CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x38,%g2,%g3,%g4,%g5)
CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x28,%g2,%g3,%g4,%g5)
CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x18,%g2,%g3,%g4,%g5)
CSUMCOPY_LASTCHUNK(%o0,%o1,%g7,0x08,%g2,%g3,%g4,%g5)
12: addx %g0, %g7, %g7
andcc %o3, 0xf, %g0 ! check for low bits set
ccte: bne cc_end_cruft ! something left, handle it out of band
andcc %o3, 8, %g0 ! begin checks for that code
retl ! return
mov %g7, %o0 ! give em the computed checksum
ccdbl: CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x00,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x20,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x40,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
CSUMCOPY_BIGCHUNK_ALIGNED(%o0,%o1,%g7,0x60,%o4,%o5,%g2,%g3,%g4,%g5,%o2,%o3)
sub %g1, 128, %g1 ! detract from length
addx %g0, %g7, %g7 ! add in last carry bit
andcc %g1, 0xffffff80, %g0 ! more to csum?
add %o0, 128, %o0 ! advance src ptr
bne ccdbl ! we did not go negative, continue looping
add %o1, 128, %o1 ! advance dest ptr
b ccmerge ! finish it off, above
andcc %g1, 0x70, %o2 ! can use table? (clears carry btw)
ccslow: cmp %g1, 0
mov 0, %g5
bleu 4f
andcc %o0, 1, %o5
be,a 1f
srl %g1, 1, %g4
sub %g1, 1, %g1
EX(ldub [%o0], %g5)
add %o0, 1, %o0
EX(stb %g5, [%o1])
srl %g1, 1, %g4
add %o1, 1, %o1
1: cmp %g4, 0
be,a 3f
andcc %g1, 1, %g0
andcc %o0, 2, %g0
be,a 1f
srl %g4, 1, %g4
EX(lduh [%o0], %o4)
sub %g1, 2, %g1
srl %o4, 8, %g2
sub %g4, 1, %g4
EX(stb %g2, [%o1])
add %o4, %g5, %g5
EX(stb %o4, [%o1 + 1])
add %o0, 2, %o0
srl %g4, 1, %g4
add %o1, 2, %o1
1: cmp %g4, 0
be,a 2f
andcc %g1, 2, %g0
EX(ld [%o0], %o4)
5: srl %o4, 24, %g2
srl %o4, 16, %g3
EX(stb %g2, [%o1])
srl %o4, 8, %g2
EX(stb %g3, [%o1 + 1])
add %o0, 4, %o0
EX(stb %g2, [%o1 + 2])
addcc %o4, %g5, %g5
EX(stb %o4, [%o1 + 3])
addx %g5, %g0, %g5 ! I am now to lazy to optimize this (question it
add %o1, 4, %o1 ! is worthy). Maybe some day - with the sll/srl
subcc %g4, 1, %g4 ! tricks
bne,a 5b
EX(ld [%o0], %o4)
sll %g5, 16, %g2
srl %g5, 16, %g5
srl %g2, 16, %g2
andcc %g1, 2, %g0
add %g2, %g5, %g5
2: be,a 3f
andcc %g1, 1, %g0
EX(lduh [%o0], %o4)
andcc %g1, 1, %g0
srl %o4, 8, %g2
add %o0, 2, %o0
EX(stb %g2, [%o1])
add %g5, %o4, %g5
EX(stb %o4, [%o1 + 1])
add %o1, 2, %o1
3: be,a 1f
sll %g5, 16, %o4
EX(ldub [%o0], %g2)
sll %g2, 8, %o4
EX(stb %g2, [%o1])
add %g5, %o4, %g5
sll %g5, 16, %o4
1: addcc %o4, %g5, %g5
srl %g5, 16, %o4
addx %g0, %o4, %g5
orcc %o5, %g0, %g0
be 4f
srl %g5, 8, %o4
and %g5, 0xff, %g2
and %o4, 0xff, %o4
sll %g2, 8, %g2
or %g2, %o4, %g5
4: addcc %g7, %g5, %g7
retl
addx %g0, %g7, %o0
/* We do these strange calculations for the csum_*_from_user case only, ie.
* we only bother with faults on loads... */
cc_fault:
retl
clr %o0