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Diffstat (limited to 'arch/mips/lib-32/csum_partial.S')
| -rw-r--r-- | arch/mips/lib-32/csum_partial.S | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/arch/mips/lib-32/csum_partial.S b/arch/mips/lib-32/csum_partial.S new file mode 100644 index 0000000..ea257db --- /dev/null +++ b/arch/mips/lib-32/csum_partial.S @@ -0,0 +1,240 @@ +/* + * 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. + * + * Copyright (C) 1998 Ralf Baechle + */ +#include <asm/asm.h> +#include <asm/regdef.h> + +#define ADDC(sum,reg) \ + addu sum, reg; \ + sltu v1, sum, reg; \ + addu sum, v1 + +#define CSUM_BIGCHUNK(src, offset, sum, t0, t1, t2, t3) \ + lw t0, (offset + 0x00)(src); \ + lw t1, (offset + 0x04)(src); \ + lw t2, (offset + 0x08)(src); \ + lw t3, (offset + 0x0c)(src); \ + ADDC(sum, t0); \ + ADDC(sum, t1); \ + ADDC(sum, t2); \ + ADDC(sum, t3); \ + lw t0, (offset + 0x10)(src); \ + lw t1, (offset + 0x14)(src); \ + lw t2, (offset + 0x18)(src); \ + lw t3, (offset + 0x1c)(src); \ + ADDC(sum, t0); \ + ADDC(sum, t1); \ + ADDC(sum, t2); \ + ADDC(sum, t3); \ + +/* + * a0: source address + * a1: length of the area to checksum + * a2: partial checksum + */ + +#define src a0 +#define dest a1 +#define sum v0 + + .text + .set noreorder + +/* unknown src alignment and < 8 bytes to go */ +small_csumcpy: + move a1, t2 + + andi t0, a1, 4 + beqz t0, 1f + andi t0, a1, 2 + + /* Still a full word to go */ + ulw t1, (src) + addiu src, 4 + ADDC(sum, t1) + +1: move t1, zero + beqz t0, 1f + andi t0, a1, 1 + + /* Still a halfword to go */ + ulhu t1, (src) + addiu src, 2 + +1: beqz t0, 1f + sll t1, t1, 16 + + lbu t2, (src) + nop + +#ifdef __MIPSEB__ + sll t2, t2, 8 +#endif + or t1, t2 + +1: ADDC(sum, t1) + + /* fold checksum */ + sll v1, sum, 16 + addu sum, v1 + sltu v1, sum, v1 + srl sum, sum, 16 + addu sum, v1 + + /* odd buffer alignment? */ + beqz t7, 1f + nop + sll v1, sum, 8 + srl sum, sum, 8 + or sum, v1 + andi sum, 0xffff +1: + .set reorder + /* Add the passed partial csum. */ + ADDC(sum, a2) + jr ra + .set noreorder + +/* ------------------------------------------------------------------------- */ + + .align 5 +LEAF(csum_partial) + move sum, zero + move t7, zero + + sltiu t8, a1, 0x8 + bnez t8, small_csumcpy /* < 8 bytes to copy */ + move t2, a1 + + beqz a1, out + andi t7, src, 0x1 /* odd buffer? */ + +hword_align: + beqz t7, word_align + andi t8, src, 0x2 + + lbu t0, (src) + subu a1, a1, 0x1 +#ifdef __MIPSEL__ + sll t0, t0, 8 +#endif + ADDC(sum, t0) + addu src, src, 0x1 + andi t8, src, 0x2 + +word_align: + beqz t8, dword_align + sltiu t8, a1, 56 + + lhu t0, (src) + subu a1, a1, 0x2 + ADDC(sum, t0) + sltiu t8, a1, 56 + addu src, src, 0x2 + +dword_align: + bnez t8, do_end_words + move t8, a1 + + andi t8, src, 0x4 + beqz t8, qword_align + andi t8, src, 0x8 + + lw t0, 0x00(src) + subu a1, a1, 0x4 + ADDC(sum, t0) + addu src, src, 0x4 + andi t8, src, 0x8 + +qword_align: + beqz t8, oword_align + andi t8, src, 0x10 + + lw t0, 0x00(src) + lw t1, 0x04(src) + subu a1, a1, 0x8 + ADDC(sum, t0) + ADDC(sum, t1) + addu src, src, 0x8 + andi t8, src, 0x10 + +oword_align: + beqz t8, begin_movement + srl t8, a1, 0x7 + + lw t3, 0x08(src) + lw t4, 0x0c(src) + lw t0, 0x00(src) + lw t1, 0x04(src) + ADDC(sum, t3) + ADDC(sum, t4) + ADDC(sum, t0) + ADDC(sum, t1) + subu a1, a1, 0x10 + addu src, src, 0x10 + srl t8, a1, 0x7 + +begin_movement: + beqz t8, 1f + andi t2, a1, 0x40 + +move_128bytes: + CSUM_BIGCHUNK(src, 0x00, sum, t0, t1, t3, t4) + CSUM_BIGCHUNK(src, 0x20, sum, t0, t1, t3, t4) + CSUM_BIGCHUNK(src, 0x40, sum, t0, t1, t3, t4) + CSUM_BIGCHUNK(src, 0x60, sum, t0, t1, t3, t4) + subu t8, t8, 0x01 + bnez t8, move_128bytes + addu src, src, 0x80 + +1: + beqz t2, 1f + andi t2, a1, 0x20 + +move_64bytes: + CSUM_BIGCHUNK(src, 0x00, sum, t0, t1, t3, t4) + CSUM_BIGCHUNK(src, 0x20, sum, t0, t1, t3, t4) + addu src, src, 0x40 + +1: + beqz t2, do_end_words + andi t8, a1, 0x1c + +move_32bytes: + CSUM_BIGCHUNK(src, 0x00, sum, t0, t1, t3, t4) + andi t8, a1, 0x1c + addu src, src, 0x20 + +do_end_words: + beqz t8, maybe_end_cruft + srl t8, t8, 0x2 + +end_words: + lw t0, (src) + subu t8, t8, 0x1 + ADDC(sum, t0) + bnez t8, end_words + addu src, src, 0x4 + +maybe_end_cruft: + andi t2, a1, 0x3 + +small_memcpy: + j small_csumcpy; move a1, t2 + beqz t2, out + move a1, t2 + +end_bytes: + lb t0, (src) + subu a1, a1, 0x1 + bnez a2, end_bytes + addu src, src, 0x1 + +out: + jr ra + move v0, sum + END(csum_partial) |
