@@ -28,6 +28,12 @@ extern int strcmp(const char *, const char *);
#define __HAVE_ARCH_STRNCMP
extern int strncmp(const char *, const char *, __kernel_size_t);
+#define __HAVE_ARCH_STRLEN
+extern __kernel_size_t strlen(const char *);
+
+#define __HAVE_ARCH_STRNLEN
+extern __kernel_size_t strnlen(const char *, __kernel_size_t);
+
#define __HAVE_ARCH_MEMCPY
extern void *memcpy(void *, const void *, __kernel_size_t);
@@ -49,6 +49,8 @@ EXPORT_SYMBOL(strchr);
EXPORT_SYMBOL(strrchr);
EXPORT_SYMBOL(strcmp);
EXPORT_SYMBOL(strncmp);
+EXPORT_SYMBOL(strlen);
+EXPORT_SYMBOL(strnlen);
EXPORT_SYMBOL(memset);
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(memmove);
@@ -3,4 +3,5 @@ lib-y := bitops.o delay.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 memcmp.o \
- strchr.o strrchr.o strcmp.o strncmp.o
+ strchr.o strrchr.o strcmp.o strncmp.o \
+ strlen.o strnlen.o
new file mode 100644
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2013 ARM Ltd.
+ * Copyright (C) 2013 Linaro.
+ *
+ * This code is based on glibc cortex strings work originally authored by Linaro
+ * and re-licensed under GPLv2 for the Linux kernel. The original code can
+ * be found @
+ *
+ * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
+ * files/head:/src/aarch64/
+ *
+ * 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>
+
+/*
+ * calculate the length of a string
+ *
+ * Parameters:
+ * x0 - const string pointer
+ * Returns:
+ * x0 - the return length of specific string
+ */
+
+/* Arguments and results. */
+#define srcin x0
+#define len x0
+
+/* Locals and temporaries. */
+#define src x1
+#define data1 x2
+#define data2 x3
+#define data2a x4
+#define has_nul1 x5
+#define has_nul2 x6
+#define tmp1 x7
+#define tmp2 x8
+#define tmp3 x9
+#define tmp4 x10
+#define zeroones x11
+#define pos x12
+
+#define REP8_01 0x0101010101010101
+#define REP8_7f 0x7f7f7f7f7f7f7f7f
+#define REP8_80 0x8080808080808080
+
+ENTRY(strlen)
+ mov zeroones, #REP8_01
+ bic src, srcin, #15
+ ands tmp1, srcin, #15
+ b.ne .Lmisaligned
+ /*
+ * NUL detection works on the principle that (X - 1) & (~X) & 0x80
+ * (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
+ * can be done in parallel across the entire word.
+ */
+ /*
+ * The inner loop deals with two Dwords at a time. This has a
+ * slightly higher start-up cost, but we should win quite quickly,
+ * especially on cores with a high number of issue slots per
+ * cycle, as we get much better parallelism out of the operations.
+ */
+.Lloop:
+ ldp data1, data2, [src], #16
+.Lrealigned:
+ sub tmp1, data1, zeroones
+ orr tmp2, data1, #REP8_7f
+ sub tmp3, data2, zeroones
+ orr tmp4, data2, #REP8_7f
+ bic has_nul1, tmp1, tmp2
+ bics has_nul2, tmp3, tmp4
+ ccmp has_nul1, #0, #0, eq /* NZCV = 0000 */
+ b.eq .Lloop
+
+ sub len, src, srcin
+ cbz has_nul1, .Lnul_in_data2
+#ifdef __ARM64EB__
+ mov data2, data1
+#endif
+ sub len, len, #8
+ mov has_nul2, has_nul1
+.Lnul_in_data2:
+#ifdef __ARM64EB__
+ /*
+ * For big-endian, carry propagation (if the final byte in the
+ * string is 0x01) means we cannot use has_nul directly. The
+ * easiest way to get the correct byte is to byte-swap the data
+ * and calculate the syndrome a second time.
+ */
+ rev data2, data2
+ sub tmp1, data2, zeroones
+ orr tmp2, data2, #REP8_7f
+ bic has_nul2, tmp1, tmp2
+#endif
+ sub len, len, #8
+ rev has_nul2, has_nul2
+ clz pos, has_nul2
+ add len, len, pos, lsr #3 /* Bits to bytes. */
+ ret
+
+.Lmisaligned:
+ cmp tmp1, #8
+ neg tmp1, tmp1
+ ldp data1, data2, [src], #16
+ lsl tmp1, tmp1, #3 /* Bytes beyond alignment -> bits. */
+ mov tmp2, #~0
+#ifdef __ARM64EB__
+ /* Big-endian. Early bytes are at MSB. */
+ lsl tmp2, tmp2, tmp1 /* Shift (tmp1 & 63). */
+#else
+ /* Little-endian. Early bytes are at LSB. */
+ lsr tmp2, tmp2, tmp1 /* Shift (tmp1 & 63). */
+#endif
+ orr data1, data1, tmp2
+ orr data2a, data2, tmp2
+ csinv data1, data1, xzr, le
+ csel data2, data2, data2a, le
+ b .Lrealigned
+ENDPROC(strlen)
new file mode 100644
@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) 2013 ARM Ltd.
+ * Copyright (C) 2013 Linaro.
+ *
+ * This code is based on glibc cortex strings work originally authored by Linaro
+ * and re-licensed under GPLv2 for the Linux kernel. The original code can
+ * be found @
+ *
+ * http://bazaar.launchpad.net/~linaro-toolchain-dev/cortex-strings/trunk/
+ * files/head:/src/aarch64/
+ *
+ * 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>
+
+/*
+ * determine the length of a fixed-size string
+ *
+ * Parameters:
+ * x0 - const string pointer
+ * x1 - maximal string length
+ * Returns:
+ * x0 - the return length of specific string
+ */
+
+/* Arguments and results. */
+#define srcin x0
+#define len x0
+#define limit x1
+
+/* Locals and temporaries. */
+#define src x2
+#define data1 x3
+#define data2 x4
+#define data2a x5
+#define has_nul1 x6
+#define has_nul2 x7
+#define tmp1 x8
+#define tmp2 x9
+#define tmp3 x10
+#define tmp4 x11
+#define zeroones x12
+#define pos x13
+#define limit_wd x14
+
+#define REP8_01 0x0101010101010101
+#define REP8_7f 0x7f7f7f7f7f7f7f7f
+#define REP8_80 0x8080808080808080
+
+ENTRY(strnlen)
+ cbz limit, .Lhit_limit
+ mov zeroones, #REP8_01
+ bic src, srcin, #15
+ ands tmp1, srcin, #15
+ b.ne .Lmisaligned
+ /* Calculate the number of full and partial words -1. */
+ sub limit_wd, limit, #1 /* Limit != 0, so no underflow. */
+ lsr limit_wd, limit_wd, #4 /* Convert to Qwords. */
+
+ /*
+ * NUL detection works on the principle that (X - 1) & (~X) & 0x80
+ * (=> (X - 1) & ~(X | 0x7f)) is non-zero iff a byte is zero, and
+ * can be done in parallel across the entire word.
+ */
+ /*
+ * The inner loop deals with two Dwords at a time. This has a
+ * slightly higher start-up cost, but we should win quite quickly,
+ * especially on cores with a high number of issue slots per
+ * cycle, as we get much better parallelism out of the operations.
+ */
+.Lloop:
+ ldp data1, data2, [src], #16
+.Lrealigned:
+ sub tmp1, data1, zeroones
+ orr tmp2, data1, #REP8_7f
+ sub tmp3, data2, zeroones
+ orr tmp4, data2, #REP8_7f
+ bic has_nul1, tmp1, tmp2
+ bic has_nul2, tmp3, tmp4
+ subs limit_wd, limit_wd, #1
+ orr tmp1, has_nul1, has_nul2
+ ccmp tmp1, #0, #0, pl /* NZCV = 0000 */
+ b.eq .Lloop
+
+ cbz tmp1, .Lhit_limit /* No null in final Qword. */
+
+ /*
+ * We know there's a null in the final Qword. The easiest thing
+ * to do now is work out the length of the string and return
+ * MIN (len, limit).
+ */
+ sub len, src, srcin
+ cbz has_nul1, .Lnul_in_data2
+#ifdef __ARM64EB__
+ mov data2, data1
+#endif
+ sub len, len, #8
+ mov has_nul2, has_nul1
+.Lnul_in_data2:
+#ifdef __ARM64EB__
+ /*
+ * For big-endian, carry propagation (if the final byte in the
+ * string is 0x01) means we cannot use has_nul directly. The
+ * easiest way to get the correct byte is to byte-swap the data
+ * and calculate the syndrome a second time.
+ */
+ rev data2, data2
+ sub tmp1, data2, zeroones
+ orr tmp2, data2, #REP8_7f
+ bic has_nul2, tmp1, tmp2
+#endif
+ sub len, len, #8
+ rev has_nul2, has_nul2
+ clz pos, has_nul2
+ add len, len, pos, lsr #3 /* Bits to bytes. */
+ cmp len, limit
+ csel len, len, limit, ls /* Return the lower value. */
+ ret
+
+.Lmisaligned:
+ /*
+ * Deal with a partial first word.
+ * We're doing two things in parallel here;
+ * 1) Calculate the number of words (but avoiding overflow if
+ * limit is near ULONG_MAX) - to do this we need to work out
+ * limit + tmp1 - 1 as a 65-bit value before shifting it;
+ * 2) Load and mask the initial data words - we force the bytes
+ * before the ones we are interested in to 0xff - this ensures
+ * early bytes will not hit any zero detection.
+ */
+ /*
+ * this operation need some cycles,
+ * some other independent instructions can following it.
+ */
+ ldp data1, data2, [src], #16
+
+ sub limit_wd, limit, #1
+ and tmp3, limit_wd, #15
+ lsr limit_wd, limit_wd, #4
+
+ add tmp3, tmp3, tmp1
+ add limit_wd, limit_wd, tmp3, lsr #4
+
+ neg tmp4, tmp1
+ lsl tmp4, tmp4, #3 /* Bytes beyond alignment -> bits. */
+
+ mov tmp2, #~0
+#ifdef __ARM64EB__
+ /* Big-endian. Early bytes are at MSB. */
+ lsl tmp2, tmp2, tmp4 /* Shift (tmp1 & 63). */
+#else
+ /* Little-endian. Early bytes are at LSB. */
+ lsr tmp2, tmp2, tmp4 /* Shift (tmp1 & 63). */
+#endif
+ cmp tmp1, #8
+
+ orr data1, data1, tmp2
+ orr data2a, data2, tmp2
+
+ csinv data1, data1, xzr, le
+ csel data2, data2, data2a, le
+ b .Lrealigned
+
+.Lhit_limit:
+ mov len, limit
+ ret
+ENDPROC(strnlen)