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-rw-r--r--arch/x86/boot/string.c378
1 files changed, 378 insertions, 0 deletions
diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
new file mode 100644
index 0000000000..1c8541ae3b
--- /dev/null
+++ b/arch/x86/boot/string.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ * Copyright 2007 rPath, Inc. - All Rights Reserved
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * Very basic string functions
+ */
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/limits.h>
+#include <asm/asm.h>
+#include "ctype.h"
+#include "string.h"
+
+#define KSTRTOX_OVERFLOW (1U << 31)
+
+/*
+ * Undef these macros so that the functions that we provide
+ * here will have the correct names regardless of how string.h
+ * may have chosen to #define them.
+ */
+#undef memcpy
+#undef memset
+#undef memcmp
+
+int memcmp(const void *s1, const void *s2, size_t len)
+{
+ bool diff;
+ asm("repe; cmpsb" CC_SET(nz)
+ : CC_OUT(nz) (diff), "+D" (s1), "+S" (s2), "+c" (len));
+ return diff;
+}
+
+/*
+ * Clang may lower `memcmp == 0` to `bcmp == 0`.
+ */
+int bcmp(const void *s1, const void *s2, size_t len)
+{
+ return memcmp(s1, s2, len);
+}
+
+int strcmp(const char *str1, const char *str2)
+{
+ const unsigned char *s1 = (const unsigned char *)str1;
+ const unsigned char *s2 = (const unsigned char *)str2;
+ int delta = 0;
+
+ while (*s1 || *s2) {
+ delta = *s1 - *s2;
+ if (delta)
+ return delta;
+ s1++;
+ s2++;
+ }
+ return 0;
+}
+
+int strncmp(const char *cs, const char *ct, size_t count)
+{
+ unsigned char c1, c2;
+
+ while (count) {
+ c1 = *cs++;
+ c2 = *ct++;
+ if (c1 != c2)
+ return c1 < c2 ? -1 : 1;
+ if (!c1)
+ break;
+ count--;
+ }
+ return 0;
+}
+
+size_t strnlen(const char *s, size_t maxlen)
+{
+ const char *es = s;
+ while (*es && maxlen) {
+ es++;
+ maxlen--;
+ }
+
+ return (es - s);
+}
+
+unsigned int atou(const char *s)
+{
+ unsigned int i = 0;
+ while (isdigit(*s))
+ i = i * 10 + (*s++ - '0');
+ return i;
+}
+
+/* Works only for digits and letters, but small and fast */
+#define TOLOWER(x) ((x) | 0x20)
+
+static unsigned int simple_guess_base(const char *cp)
+{
+ if (cp[0] == '0') {
+ if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
+ return 16;
+ else
+ return 8;
+ } else {
+ return 10;
+ }
+}
+
+/**
+ * simple_strtoull - convert a string to an unsigned long long
+ * @cp: The start of the string
+ * @endp: A pointer to the end of the parsed string will be placed here
+ * @base: The number base to use
+ */
+unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
+{
+ unsigned long long result = 0;
+
+ if (!base)
+ base = simple_guess_base(cp);
+
+ if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
+ cp += 2;
+
+ while (isxdigit(*cp)) {
+ unsigned int value;
+
+ value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
+ if (value >= base)
+ break;
+ result = result * base + value;
+ cp++;
+ }
+ if (endp)
+ *endp = (char *)cp;
+
+ return result;
+}
+
+long simple_strtol(const char *cp, char **endp, unsigned int base)
+{
+ if (*cp == '-')
+ return -simple_strtoull(cp + 1, endp, base);
+
+ return simple_strtoull(cp, endp, base);
+}
+
+/**
+ * strlen - Find the length of a string
+ * @s: The string to be sized
+ */
+size_t strlen(const char *s)
+{
+ const char *sc;
+
+ for (sc = s; *sc != '\0'; ++sc)
+ /* nothing */;
+ return sc - s;
+}
+
+/**
+ * strstr - Find the first substring in a %NUL terminated string
+ * @s1: The string to be searched
+ * @s2: The string to search for
+ */
+char *strstr(const char *s1, const char *s2)
+{
+ size_t l1, l2;
+
+ l2 = strlen(s2);
+ if (!l2)
+ return (char *)s1;
+ l1 = strlen(s1);
+ while (l1 >= l2) {
+ l1--;
+ if (!memcmp(s1, s2, l2))
+ return (char *)s1;
+ s1++;
+ }
+ return NULL;
+}
+
+/**
+ * strchr - Find the first occurrence of the character c in the string s.
+ * @s: the string to be searched
+ * @c: the character to search for
+ */
+char *strchr(const char *s, int c)
+{
+ while (*s != (char)c)
+ if (*s++ == '\0')
+ return NULL;
+ return (char *)s;
+}
+
+static inline u64 __div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+ union {
+ u64 v64;
+ u32 v32[2];
+ } d = { dividend };
+ u32 upper;
+
+ upper = d.v32[1];
+ d.v32[1] = 0;
+ if (upper >= divisor) {
+ d.v32[1] = upper / divisor;
+ upper %= divisor;
+ }
+ asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) :
+ "rm" (divisor), "0" (d.v32[0]), "1" (upper));
+ return d.v64;
+}
+
+static inline u64 __div_u64(u64 dividend, u32 divisor)
+{
+ u32 remainder;
+
+ return __div_u64_rem(dividend, divisor, &remainder);
+}
+
+static inline char _tolower(const char c)
+{
+ return c | 0x20;
+}
+
+static const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
+{
+ if (*base == 0) {
+ if (s[0] == '0') {
+ if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
+ *base = 16;
+ else
+ *base = 8;
+ } else
+ *base = 10;
+ }
+ if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
+ s += 2;
+ return s;
+}
+
+/*
+ * Convert non-negative integer string representation in explicitly given radix
+ * to an integer.
+ * Return number of characters consumed maybe or-ed with overflow bit.
+ * If overflow occurs, result integer (incorrect) is still returned.
+ *
+ * Don't you dare use this function.
+ */
+static unsigned int _parse_integer(const char *s,
+ unsigned int base,
+ unsigned long long *p)
+{
+ unsigned long long res;
+ unsigned int rv;
+
+ res = 0;
+ rv = 0;
+ while (1) {
+ unsigned int c = *s;
+ unsigned int lc = c | 0x20; /* don't tolower() this line */
+ unsigned int val;
+
+ if ('0' <= c && c <= '9')
+ val = c - '0';
+ else if ('a' <= lc && lc <= 'f')
+ val = lc - 'a' + 10;
+ else
+ break;
+
+ if (val >= base)
+ break;
+ /*
+ * Check for overflow only if we are within range of
+ * it in the max base we support (16)
+ */
+ if (unlikely(res & (~0ull << 60))) {
+ if (res > __div_u64(ULLONG_MAX - val, base))
+ rv |= KSTRTOX_OVERFLOW;
+ }
+ res = res * base + val;
+ rv++;
+ s++;
+ }
+ *p = res;
+ return rv;
+}
+
+static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+ unsigned long long _res;
+ unsigned int rv;
+
+ s = _parse_integer_fixup_radix(s, &base);
+ rv = _parse_integer(s, base, &_res);
+ if (rv & KSTRTOX_OVERFLOW)
+ return -ERANGE;
+ if (rv == 0)
+ return -EINVAL;
+ s += rv;
+ if (*s == '\n')
+ s++;
+ if (*s)
+ return -EINVAL;
+ *res = _res;
+ return 0;
+}
+
+/**
+ * kstrtoull - convert a string to an unsigned long long
+ * @s: The start of the string. The string must be null-terminated, and may also
+ * include a single newline before its terminating null. The first character
+ * may also be a plus sign, but not a minus sign.
+ * @base: The number base to use. The maximum supported base is 16. If base is
+ * given as 0, then the base of the string is automatically detected with the
+ * conventional semantics - If it begins with 0x the number will be parsed as a
+ * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
+ * parsed as an octal number. Otherwise it will be parsed as a decimal.
+ * @res: Where to write the result of the conversion on success.
+ *
+ * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
+ * Used as a replacement for the obsolete simple_strtoull. Return code must
+ * be checked.
+ */
+int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+ if (s[0] == '+')
+ s++;
+ return _kstrtoull(s, base, res);
+}
+
+static int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+ unsigned long long tmp;
+ int rv;
+
+ rv = kstrtoull(s, base, &tmp);
+ if (rv < 0)
+ return rv;
+ if (tmp != (unsigned long)tmp)
+ return -ERANGE;
+ *res = tmp;
+ return 0;
+}
+
+/**
+ * boot_kstrtoul - convert a string to an unsigned long
+ * @s: The start of the string. The string must be null-terminated, and may also
+ * include a single newline before its terminating null. The first character
+ * may also be a plus sign, but not a minus sign.
+ * @base: The number base to use. The maximum supported base is 16. If base is
+ * given as 0, then the base of the string is automatically detected with the
+ * conventional semantics - If it begins with 0x the number will be parsed as a
+ * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
+ * parsed as an octal number. Otherwise it will be parsed as a decimal.
+ * @res: Where to write the result of the conversion on success.
+ *
+ * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
+ * Used as a replacement for the simple_strtoull.
+ */
+int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+ /*
+ * We want to shortcut function call, but
+ * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
+ */
+ if (sizeof(unsigned long) == sizeof(unsigned long long) &&
+ __alignof__(unsigned long) == __alignof__(unsigned long long))
+ return kstrtoull(s, base, (unsigned long long *)res);
+ else
+ return _kstrtoul(s, base, res);
+}