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-rw-r--r--arch/mips/lib-32/csum_partial.S240
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
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index 000000000000..ea257dbdcc40
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+++ 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)