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authorCatalin Marinas <catalin.marinas@arm.com>2013-03-21 16:23:43 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2013-03-21 17:39:30 +0000
commit2b8cac814cd5a0a305d62dcd1d589faccb705a4d (patch)
tree62340ae9d079bdf28747eff9c5a9e12530f52895 /arch/arm64/lib
parentarm64: klib: Optimised memory functions (diff)
downloadlinux-dev-2b8cac814cd5a0a305d62dcd1d589faccb705a4d.tar.xz
linux-dev-2b8cac814cd5a0a305d62dcd1d589faccb705a4d.zip
arm64: klib: Optimised string functions
This patch introduces AArch64-specific string functions (strchr, strrchr). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/lib')
-rw-r--r--arch/arm64/lib/Makefile3
-rw-r--r--arch/arm64/lib/strchr.S42
-rw-r--r--arch/arm64/lib/strrchr.S43
3 files changed, 87 insertions, 1 deletions
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 2fce1398aa24..59acc0ef0462 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -2,4 +2,5 @@ lib-y := bitops.o delay.o \
strncpy_from_user.o strnlen_user.o clear_user.o \
copy_from_user.o copy_to_user.o copy_in_user.o \
copy_page.o clear_page.o \
- memchr.o memcpy.o memmove.o memset.o
+ memchr.o memcpy.o memmove.o memset.o \
+ strchr.o strrchr.o
diff --git a/arch/arm64/lib/strchr.S b/arch/arm64/lib/strchr.S
new file mode 100644
index 000000000000..dae0cf5591f9
--- /dev/null
+++ b/arch/arm64/lib/strchr.S
@@ -0,0 +1,42 @@
+/*
+ * Based on arch/arm/lib/strchr.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 the first occurrence of a character in a string.
+ *
+ * Parameters:
+ * x0 - str
+ * x1 - c
+ * Returns:
+ * x0 - address of first occurrence of 'c' or 0
+ */
+ENTRY(strchr)
+ and w1, w1, #0xff
+1: ldrb w2, [x0], #1
+ cmp w2, w1
+ ccmp w2, wzr, #4, ne
+ b.ne 1b
+ sub x0, x0, #1
+ cmp w2, w1
+ csel x0, x0, xzr, eq
+ ret
+ENDPROC(strchr)
diff --git a/arch/arm64/lib/strrchr.S b/arch/arm64/lib/strrchr.S
new file mode 100644
index 000000000000..61eabd9a289a
--- /dev/null
+++ b/arch/arm64/lib/strrchr.S
@@ -0,0 +1,43 @@
+/*
+ * Based on arch/arm/lib/strrchr.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 the last occurrence of a character in a string.
+ *
+ * Parameters:
+ * x0 - str
+ * x1 - c
+ * Returns:
+ * x0 - address of last occurrence of 'c' or 0
+ */
+ENTRY(strrchr)
+ mov x3, #0
+ and w1, w1, #0xff
+1: ldrb w2, [x0], #1
+ cbz w2, 2f
+ cmp w2, w1
+ b.ne 1b
+ sub x3, x0, #1
+ b 1b
+2: mov x0, x3
+ ret
+ENDPROC(strrchr)