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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /include/linux/bitops.h
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/linux/bitops.h')
-rw-r--r--include/linux/bitops.h377
1 files changed, 377 insertions, 0 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h
new file mode 100644
index 000000000..2ba557e06
--- /dev/null
+++ b/include/linux/bitops.h
@@ -0,0 +1,377 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_BITOPS_H
+#define _LINUX_BITOPS_H
+
+#include <asm/types.h>
+#include <linux/bits.h>
+#include <linux/typecheck.h>
+
+#include <uapi/linux/kernel.h>
+
+/* Set bits in the first 'n' bytes when loaded from memory */
+#ifdef __LITTLE_ENDIAN
+# define aligned_byte_mask(n) ((1UL << 8*(n))-1)
+#else
+# define aligned_byte_mask(n) (~0xffUL << (BITS_PER_LONG - 8 - 8*(n)))
+#endif
+
+#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE)
+#define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))
+#define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))
+#define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))
+#define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
+
+extern unsigned int __sw_hweight8(unsigned int w);
+extern unsigned int __sw_hweight16(unsigned int w);
+extern unsigned int __sw_hweight32(unsigned int w);
+extern unsigned long __sw_hweight64(__u64 w);
+
+/*
+ * Defined here because those may be needed by architecture-specific static
+ * inlines.
+ */
+
+#include <asm-generic/bitops/generic-non-atomic.h>
+
+/*
+ * Many architecture-specific non-atomic bitops contain inline asm code and due
+ * to that the compiler can't optimize them to compile-time expressions or
+ * constants. In contrary, generic_*() helpers are defined in pure C and
+ * compilers optimize them just well.
+ * Therefore, to make `unsigned long foo = 0; __set_bit(BAR, &foo)` effectively
+ * equal to `unsigned long foo = BIT(BAR)`, pick the generic C alternative when
+ * the arguments can be resolved at compile time. That expression itself is a
+ * constant and doesn't bring any functional changes to the rest of cases.
+ * The casts to `uintptr_t` are needed to mitigate `-Waddress` warnings when
+ * passing a bitmap from .bss or .data (-> `!!addr` is always true).
+ */
+#define bitop(op, nr, addr) \
+ ((__builtin_constant_p(nr) && \
+ __builtin_constant_p((uintptr_t)(addr) != (uintptr_t)NULL) && \
+ (uintptr_t)(addr) != (uintptr_t)NULL && \
+ __builtin_constant_p(*(const unsigned long *)(addr))) ? \
+ const##op(nr, addr) : op(nr, addr))
+
+#define __set_bit(nr, addr) bitop(___set_bit, nr, addr)
+#define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr)
+#define __change_bit(nr, addr) bitop(___change_bit, nr, addr)
+#define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr)
+#define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr)
+#define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr)
+#define test_bit(nr, addr) bitop(_test_bit, nr, addr)
+#define test_bit_acquire(nr, addr) bitop(_test_bit_acquire, nr, addr)
+
+/*
+ * Include this here because some architectures need generic_ffs/fls in
+ * scope
+ */
+#include <asm/bitops.h>
+
+/* Check that the bitops prototypes are sane */
+#define __check_bitop_pr(name) \
+ static_assert(__same_type(arch_##name, generic_##name) && \
+ __same_type(const_##name, generic_##name) && \
+ __same_type(_##name, generic_##name))
+
+__check_bitop_pr(__set_bit);
+__check_bitop_pr(__clear_bit);
+__check_bitop_pr(__change_bit);
+__check_bitop_pr(__test_and_set_bit);
+__check_bitop_pr(__test_and_clear_bit);
+__check_bitop_pr(__test_and_change_bit);
+__check_bitop_pr(test_bit);
+
+#undef __check_bitop_pr
+
+static inline int get_bitmask_order(unsigned int count)
+{
+ int order;
+
+ order = fls(count);
+ return order; /* We could be slightly more clever with -1 here... */
+}
+
+static __always_inline unsigned long hweight_long(unsigned long w)
+{
+ return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);
+}
+
+/**
+ * rol64 - rotate a 64-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u64 rol64(__u64 word, unsigned int shift)
+{
+ return (word << (shift & 63)) | (word >> ((-shift) & 63));
+}
+
+/**
+ * ror64 - rotate a 64-bit value right
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u64 ror64(__u64 word, unsigned int shift)
+{
+ return (word >> (shift & 63)) | (word << ((-shift) & 63));
+}
+
+/**
+ * rol32 - rotate a 32-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u32 rol32(__u32 word, unsigned int shift)
+{
+ return (word << (shift & 31)) | (word >> ((-shift) & 31));
+}
+
+/**
+ * ror32 - rotate a 32-bit value right
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u32 ror32(__u32 word, unsigned int shift)
+{
+ return (word >> (shift & 31)) | (word << ((-shift) & 31));
+}
+
+/**
+ * rol16 - rotate a 16-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u16 rol16(__u16 word, unsigned int shift)
+{
+ return (word << (shift & 15)) | (word >> ((-shift) & 15));
+}
+
+/**
+ * ror16 - rotate a 16-bit value right
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u16 ror16(__u16 word, unsigned int shift)
+{
+ return (word >> (shift & 15)) | (word << ((-shift) & 15));
+}
+
+/**
+ * rol8 - rotate an 8-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u8 rol8(__u8 word, unsigned int shift)
+{
+ return (word << (shift & 7)) | (word >> ((-shift) & 7));
+}
+
+/**
+ * ror8 - rotate an 8-bit value right
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u8 ror8(__u8 word, unsigned int shift)
+{
+ return (word >> (shift & 7)) | (word << ((-shift) & 7));
+}
+
+/**
+ * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0<=index<32) to sign bit
+ *
+ * This is safe to use for 16- and 8-bit types as well.
+ */
+static __always_inline __s32 sign_extend32(__u32 value, int index)
+{
+ __u8 shift = 31 - index;
+ return (__s32)(value << shift) >> shift;
+}
+
+/**
+ * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
+ * @value: value to sign extend
+ * @index: 0 based bit index (0<=index<64) to sign bit
+ */
+static __always_inline __s64 sign_extend64(__u64 value, int index)
+{
+ __u8 shift = 63 - index;
+ return (__s64)(value << shift) >> shift;
+}
+
+static inline unsigned fls_long(unsigned long l)
+{
+ if (sizeof(l) == 4)
+ return fls(l);
+ return fls64(l);
+}
+
+static inline int get_count_order(unsigned int count)
+{
+ if (count == 0)
+ return -1;
+
+ return fls(--count);
+}
+
+/**
+ * get_count_order_long - get order after rounding @l up to power of 2
+ * @l: parameter
+ *
+ * it is same as get_count_order() but with long type parameter
+ */
+static inline int get_count_order_long(unsigned long l)
+{
+ if (l == 0UL)
+ return -1;
+ return (int)fls_long(--l);
+}
+
+/**
+ * __ffs64 - find first set bit in a 64 bit word
+ * @word: The 64 bit word
+ *
+ * On 64 bit arches this is a synonym for __ffs
+ * The result is not defined if no bits are set, so check that @word
+ * is non-zero before calling this.
+ */
+static inline unsigned long __ffs64(u64 word)
+{
+#if BITS_PER_LONG == 32
+ if (((u32)word) == 0UL)
+ return __ffs((u32)(word >> 32)) + 32;
+#elif BITS_PER_LONG != 64
+#error BITS_PER_LONG not 32 or 64
+#endif
+ return __ffs((unsigned long)word);
+}
+
+/**
+ * fns - find N'th set bit in a word
+ * @word: The word to search
+ * @n: Bit to find
+ */
+static inline unsigned long fns(unsigned long word, unsigned int n)
+{
+ unsigned int bit;
+
+ while (word) {
+ bit = __ffs(word);
+ if (n-- == 0)
+ return bit;
+ __clear_bit(bit, &word);
+ }
+
+ return BITS_PER_LONG;
+}
+
+/**
+ * assign_bit - Assign value to a bit in memory
+ * @nr: the bit to set
+ * @addr: the address to start counting from
+ * @value: the value to assign
+ */
+static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
+ bool value)
+{
+ if (value)
+ set_bit(nr, addr);
+ else
+ clear_bit(nr, addr);
+}
+
+static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
+ bool value)
+{
+ if (value)
+ __set_bit(nr, addr);
+ else
+ __clear_bit(nr, addr);
+}
+
+/**
+ * __ptr_set_bit - Set bit in a pointer's value
+ * @nr: the bit to set
+ * @addr: the address of the pointer variable
+ *
+ * Example:
+ * void *p = foo();
+ * __ptr_set_bit(bit, &p);
+ */
+#define __ptr_set_bit(nr, addr) \
+ ({ \
+ typecheck_pointer(*(addr)); \
+ __set_bit(nr, (unsigned long *)(addr)); \
+ })
+
+/**
+ * __ptr_clear_bit - Clear bit in a pointer's value
+ * @nr: the bit to clear
+ * @addr: the address of the pointer variable
+ *
+ * Example:
+ * void *p = foo();
+ * __ptr_clear_bit(bit, &p);
+ */
+#define __ptr_clear_bit(nr, addr) \
+ ({ \
+ typecheck_pointer(*(addr)); \
+ __clear_bit(nr, (unsigned long *)(addr)); \
+ })
+
+/**
+ * __ptr_test_bit - Test bit in a pointer's value
+ * @nr: the bit to test
+ * @addr: the address of the pointer variable
+ *
+ * Example:
+ * void *p = foo();
+ * if (__ptr_test_bit(bit, &p)) {
+ * ...
+ * } else {
+ * ...
+ * }
+ */
+#define __ptr_test_bit(nr, addr) \
+ ({ \
+ typecheck_pointer(*(addr)); \
+ test_bit(nr, (unsigned long *)(addr)); \
+ })
+
+#ifdef __KERNEL__
+
+#ifndef set_mask_bits
+#define set_mask_bits(ptr, mask, bits) \
+({ \
+ const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \
+ typeof(*(ptr)) old__, new__; \
+ \
+ old__ = READ_ONCE(*(ptr)); \
+ do { \
+ new__ = (old__ & ~mask__) | bits__; \
+ } while (!try_cmpxchg(ptr, &old__, new__)); \
+ \
+ old__; \
+})
+#endif
+
+#ifndef bit_clear_unless
+#define bit_clear_unless(ptr, clear, test) \
+({ \
+ const typeof(*(ptr)) clear__ = (clear), test__ = (test);\
+ typeof(*(ptr)) old__, new__; \
+ \
+ old__ = READ_ONCE(*(ptr)); \
+ do { \
+ if (old__ & test__) \
+ break; \
+ new__ = old__ & ~clear__; \
+ } while (!try_cmpxchg(ptr, &old__, new__)); \
+ \
+ !(old__ & test__); \
+})
+#endif
+
+#endif /* __KERNEL__ */
+#endif