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Diffstat (limited to 'arch/sparc64/lib/checksum.S')
| -rw-r--r-- | arch/sparc64/lib/checksum.S | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/arch/sparc64/lib/checksum.S b/arch/sparc64/lib/checksum.S new file mode 100644 index 000000000000..ba9cd3ccc2b2 --- /dev/null +++ b/arch/sparc64/lib/checksum.S @@ -0,0 +1,172 @@ +/* checksum.S: Sparc V9 optimized checksum code. + * + * Copyright(C) 1995 Linus Torvalds + * Copyright(C) 1995 Miguel de Icaza + * Copyright(C) 1996, 2000 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 + */ + + .text + +csum_partial_fix_alignment: + /* We checked for zero length already, so there must be + * at least one byte. + */ + be,pt %icc, 1f + nop + ldub [%o0 + 0x00], %o4 + add %o0, 1, %o0 + sub %o1, 1, %o1 +1: andcc %o0, 0x2, %g0 + be,pn %icc, csum_partial_post_align + cmp %o1, 2 + blu,pn %icc, csum_partial_end_cruft + nop + lduh [%o0 + 0x00], %o5 + add %o0, 2, %o0 + sub %o1, 2, %o1 + ba,pt %xcc, csum_partial_post_align + add %o5, %o4, %o4 + + .align 32 + .globl csum_partial +csum_partial: /* %o0=buff, %o1=len, %o2=sum */ + prefetch [%o0 + 0x000], #n_reads + clr %o4 + prefetch [%o0 + 0x040], #n_reads + brz,pn %o1, csum_partial_finish + andcc %o0, 0x3, %g0 + + /* We "remember" whether the lowest bit in the address + * was set in %g7. Because if it is, we have to swap + * upper and lower 8 bit fields of the sum we calculate. + */ + bne,pn %icc, csum_partial_fix_alignment + andcc %o0, 0x1, %g7 + +csum_partial_post_align: + prefetch [%o0 + 0x080], #n_reads + andncc %o1, 0x3f, %o3 + + prefetch [%o0 + 0x0c0], #n_reads + sub %o1, %o3, %o1 + brz,pn %o3, 2f + prefetch [%o0 + 0x100], #n_reads + + /* So that we don't need to use the non-pairing + * add-with-carry instructions we accumulate 32-bit + * values into a 64-bit register. At the end of the + * loop we fold it down to 32-bits and so on. + */ + prefetch [%o0 + 0x140], #n_reads +1: lduw [%o0 + 0x00], %o5 + lduw [%o0 + 0x04], %g1 + lduw [%o0 + 0x08], %g2 + add %o4, %o5, %o4 + lduw [%o0 + 0x0c], %g3 + add %o4, %g1, %o4 + lduw [%o0 + 0x10], %o5 + add %o4, %g2, %o4 + lduw [%o0 + 0x14], %g1 + add %o4, %g3, %o4 + lduw [%o0 + 0x18], %g2 + add %o4, %o5, %o4 + lduw [%o0 + 0x1c], %g3 + add %o4, %g1, %o4 + lduw [%o0 + 0x20], %o5 + add %o4, %g2, %o4 + lduw [%o0 + 0x24], %g1 + add %o4, %g3, %o4 + lduw [%o0 + 0x28], %g2 + add %o4, %o5, %o4 + lduw [%o0 + 0x2c], %g3 + add %o4, %g1, %o4 + lduw [%o0 + 0x30], %o5 + add %o4, %g2, %o4 + lduw [%o0 + 0x34], %g1 + add %o4, %g3, %o4 + lduw [%o0 + 0x38], %g2 + add %o4, %o5, %o4 + lduw [%o0 + 0x3c], %g3 + add %o4, %g1, %o4 + prefetch [%o0 + 0x180], #n_reads + add %o4, %g2, %o4 + subcc %o3, 0x40, %o3 + add %o0, 0x40, %o0 + bne,pt %icc, 1b + add %o4, %g3, %o4 + +2: and %o1, 0x3c, %o3 + brz,pn %o3, 2f + sub %o1, %o3, %o1 +1: lduw [%o0 + 0x00], %o5 + subcc %o3, 0x4, %o3 + add %o0, 0x4, %o0 + bne,pt %icc, 1b + add %o4, %o5, %o4 + +2: + /* fold 64-->32 */ + srlx %o4, 32, %o5 + srl %o4, 0, %o4 + add %o4, %o5, %o4 + srlx %o4, 32, %o5 + srl %o4, 0, %o4 + add %o4, %o5, %o4 + + /* fold 32-->16 */ + sethi %hi(0xffff0000), %g1 + srl %o4, 16, %o5 + andn %o4, %g1, %g2 + add %o5, %g2, %o4 + srl %o4, 16, %o5 + andn %o4, %g1, %g2 + add %o5, %g2, %o4 + +csum_partial_end_cruft: + /* %o4 has the 16-bit sum we have calculated so-far. */ + cmp %o1, 2 + blu,pt %icc, 1f + nop + lduh [%o0 + 0x00], %o5 + sub %o1, 2, %o1 + add %o0, 2, %o0 + add %o4, %o5, %o4 +1: brz,pt %o1, 1f + nop + ldub [%o0 + 0x00], %o5 + sub %o1, 1, %o1 + add %o0, 1, %o0 + sllx %o5, 8, %o5 + add %o4, %o5, %o4 +1: + /* fold 32-->16 */ + sethi %hi(0xffff0000), %g1 + srl %o4, 16, %o5 + andn %o4, %g1, %g2 + add %o5, %g2, %o4 + srl %o4, 16, %o5 + andn %o4, %g1, %g2 + add %o5, %g2, %o4 + +1: brz,pt %g7, 1f + nop + + /* We started with an odd byte, byte-swap the result. */ + srl %o4, 8, %o5 + and %o4, 0xff, %g1 + sll %g1, 8, %g1 + or %o5, %g1, %o4 + +1: add %o2, %o4, %o2 + +csum_partial_finish: + retl + mov %o2, %o0 |