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-rw-r--r--arch/sparc/lib/checksum_32.S467
1 files changed, 467 insertions, 0 deletions
diff --git a/arch/sparc/lib/checksum_32.S b/arch/sparc/lib/checksum_32.S
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+/* 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 <asm/errno.h>
+#include <asm/export.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
+
+#define EXT(start,end) \
+ .section __ex_table,ALLOC; \
+ .align 4; \
+ .word start, 0, end, 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) \
+ ldd [src + off + 0x00], t0; \
+ ldd [src + off + 0x08], t2; \
+ addxcc t0, sum, sum; \
+ ldd [src + off + 0x10], t4; \
+ addxcc t1, sum, sum; \
+ ldd [src + off + 0x18], t6; \
+ addxcc t2, sum, sum; \
+ std t0, [dst + off + 0x00]; \
+ addxcc t3, sum, sum; \
+ std t2, [dst + off + 0x08]; \
+ addxcc t4, sum, sum; \
+ std t4, [dst + off + 0x10]; \
+ addxcc t5, sum, sum; \
+ 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) \
+ ldd [src + off + 0x00], t0; \
+ ldd [src + off + 0x08], t2; \
+ ldd [src + off + 0x10], t4; \
+ ldd [src + off + 0x18], t6; \
+ st t0, [dst + off + 0x00]; \
+ addxcc t0, sum, sum; \
+ st t1, [dst + off + 0x04]; \
+ addxcc t1, sum, sum; \
+ st t2, [dst + off + 0x08]; \
+ addxcc t2, sum, sum; \
+ st t3, [dst + off + 0x0c]; \
+ addxcc t3, sum, sum; \
+ st t4, [dst + off + 0x10]; \
+ addxcc t4, sum, sum; \
+ st t5, [dst + off + 0x14]; \
+ addxcc t5, sum, sum; \
+ st t6, [dst + off + 0x18]; \
+ addxcc t6, sum, sum; \
+ st t7, [dst + off + 0x1c]; \
+ addxcc t7, sum, sum;
+
+ /* Yuck, 6 superscalar cycles... */
+#define CSUMCOPY_LASTCHUNK(src, dst, sum, off, t0, t1, t2, t3) \
+ ldd [src - off - 0x08], t0; \
+ ldd [src - off - 0x00], t2; \
+ addxcc t0, sum, sum; \
+ st t0, [dst - off - 0x08]; \
+ addxcc t1, sum, sum; \
+ st t1, [dst - off - 0x04]; \
+ addxcc t2, sum, sum; \
+ st t2, [dst - off - 0x00]; \
+ addxcc t3, sum, sum; \
+ 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)
+10: EXT(5b, 10b) ! note for exception handling
+ 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: EXT(cctbl, 12b) ! note for exception table handling
+ 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)
+11: EXT(ccdbl, 11b) ! note for exception table handling
+ 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
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 09:05:14 +0000