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-rw-r--r--arch/mips/lib/memset.S141
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/mips/lib/memset.S b/arch/mips/lib/memset.S
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+++ b/arch/mips/lib/memset.S
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+/*
+ * include/asm-mips/types.h
+ *
+ * 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 by Ralf Baechle
+ *
+ * $Id: memset.S,v 1.2 1998/04/25 17:01:45 ralf Exp $
+ */
+#include <asm/asm.h>
+#include <asm/offset.h>
+#include <asm/regdef.h>
+
+#define EX(insn,reg,addr,handler) \
+9: insn reg, addr; \
+ .section __ex_table,"a"; \
+ PTR 9b, handler; \
+ .previous
+
+#define F_FILL64(dst, offset, val, fixup) \
+ EX(sw, val, (offset + 0x00)(dst), fixup); \
+ EX(sw, val, (offset + 0x04)(dst), fixup); \
+ EX(sw, val, (offset + 0x08)(dst), fixup); \
+ EX(sw, val, (offset + 0x0c)(dst), fixup); \
+ EX(sw, val, (offset + 0x10)(dst), fixup); \
+ EX(sw, val, (offset + 0x14)(dst), fixup); \
+ EX(sw, val, (offset + 0x18)(dst), fixup); \
+ EX(sw, val, (offset + 0x1c)(dst), fixup); \
+ EX(sw, val, (offset + 0x20)(dst), fixup); \
+ EX(sw, val, (offset + 0x24)(dst), fixup); \
+ EX(sw, val, (offset + 0x28)(dst), fixup); \
+ EX(sw, val, (offset + 0x2c)(dst), fixup); \
+ EX(sw, val, (offset + 0x30)(dst), fixup); \
+ EX(sw, val, (offset + 0x34)(dst), fixup); \
+ EX(sw, val, (offset + 0x38)(dst), fixup); \
+ EX(sw, val, (offset + 0x3c)(dst), fixup)
+
+/*
+ * memset(void *s, int c, size_t n)
+ *
+ * a0: start of area to clear
+ * a1: char to fill with
+ * a2: size of area to clear
+ */
+ .set noreorder
+ .align 5
+LEAF(memset)
+ beqz a1, 1f
+ move v0, a0 /* result */
+
+ andi a1, 0xff /* spread fillword */
+ sll t1, a1, 8
+ or a1, t1
+ sll t1, a1, 16
+ or a1, t1
+1:
+
+EXPORT(__bzero)
+ sltiu t0, a2, 4 /* very small region? */
+ bnez t0, small_memset
+ andi t0, a0, 3 /* aligned? */
+
+ beqz t0, 1f
+ subu t0, 4 /* alignment in bytes */
+
+#ifdef __MIPSEB__
+ EX(swl, a1, (a0), first_fixup) /* make word aligned */
+#endif
+#ifdef __MIPSEL__
+ EX(swr, a1, (a0), first_fixup) /* make word aligned */
+#endif
+ subu a0, t0 /* word align ptr */
+ addu a2, t0 /* correct size */
+
+1: ori t1, a2, 0x3f /* # of full blocks */
+ xori t1, 0x3f
+ beqz t1, memset_partial /* no block to fill */
+ andi t0, a2, 0x3c
+
+ addu t1, a0 /* end address */
+ .set reorder
+1: addiu a0, 64
+ F_FILL64(a0, -64, a1, fwd_fixup)
+ bne t1, a0, 1b
+ .set noreorder
+
+memset_partial:
+ la t1, 2f /* where to start */
+ subu t1, t0
+ jr t1
+ addu a0, t0 /* dest ptr */
+
+ F_FILL64(a0, -64, a1, partial_fixup) /* ... but first do wrds ... */
+2: andi a2, 3 /* 0 <= n <= 3 to go */
+
+ beqz a2, 1f
+ addu a0, a2 /* What's left */
+#ifdef __MIPSEB__
+ EX(swr, a1, -1(a0), last_fixup)
+#endif
+#ifdef __MIPSEL__
+ EX(swl, a1, -1(a0), last_fixup)
+#endif
+1: jr ra
+ move a2, zero
+
+small_memset:
+ beqz a2, 2f
+ addu t1, a0, a2
+
+1: addiu a0, 1 /* fill bytewise */
+ bne t1, a0, 1b
+ sb a1, -1(a0)
+
+2: jr ra /* done */
+ move a2, zero
+ END(memset)
+
+first_fixup:
+ jr ra
+ nop
+
+fwd_fixup:
+ lw t0, THREAD_BUADDR($28)
+ andi a2, 0x3f
+ addu a2, t1
+ jr ra
+ subu a2, t0
+
+partial_fixup:
+ lw t0, THREAD_BUADDR($28)
+ andi a2, 3
+ addu a2, t1
+ jr ra
+ subu a2, t0
+
+last_fixup:
+ jr ra
+ andi v1, a2, 3