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authorCatalin Marinas <catalin.marinas@arm.com>2013-03-21 16:16:43 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2013-03-21 17:39:29 +0000
commit4a8992271c843cb5bcd3321bf6a02eb251280b1d (patch)
tree100bdf14109f0d6b6ac559db6f25a337daa4280c /arch/arm64/lib/memchr.S
parent792072066d30372772137be9ee2f4d72d77329f9 (diff)
downloadop-kernel-dev-4a8992271c843cb5bcd3321bf6a02eb251280b1d.zip
op-kernel-dev-4a8992271c843cb5bcd3321bf6a02eb251280b1d.tar.gz
arm64: klib: Optimised memory functions
This patch introduces AArch64-specific memory functions (memcpy, memmove, memchr, memset). These functions are not optimised for any CPU implementation but can be used as a starting point once hardware is available. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/lib/memchr.S')
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diff --git a/arch/arm64/lib/memchr.S b/arch/arm64/lib/memchr.S
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+/*
+ * Based on arch/arm/lib/memchr.S
+ *
+ * Copyright (C) 1995-2000 Russell King
+ * Copyright (C) 2013 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+#include <asm/assembler.h>
+
+/*
+ * Find a character in an area of memory.
+ *
+ * Parameters:
+ * x0 - buf
+ * x1 - c
+ * x2 - n
+ * Returns:
+ * x0 - address of first occurrence of 'c' or 0
+ */
+ENTRY(memchr)
+ and w1, w1, #0xff
+1: subs x2, x2, #1
+ b.mi 2f
+ ldrb w3, [x0], #1
+ cmp w3, w1
+ b.ne 1b
+ sub x0, x0, #1
+ ret
+2: mov x0, #0
+ ret
+ENDPROC(memchr)
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