1 /* SPDX-License-Identifier: GPL-2.0 */
25  * Defined here because those may be needed by architecture-specific static
29 #include <asm-generic/bitops/generic-non-atomic.h>
32  * Many architecture-specific non-atomic bitops contain inline asm code and due
33  * to that the compiler can't optimize them to compile-time expressions or
37  * equal to `unsigned long foo = BIT(BAR)`, pick the generic C alternative when
40  * The casts to `uintptr_t` are needed to mitigate `-Waddress` warnings when
41  * passing a bitmap from .bss or .data (-> `!!addr` is always true).
51  * The following macros are non-atomic versions of their non-underscored
92 	return order;	/* We could be slightly more clever with -1 here... */  in get_bitmask_order()
101  * rol64 - rotate a 64-bit value left
103  * @shift: bits to roll
105 static inline __u64 rol64(__u64 word, unsigned int shift)  in rol64()  argument
107 	return (word << (shift & 63)) | (word >> ((-shift) & 63));  in rol64()
111  * ror64 - rotate a 64-bit value right
113  * @shift: bits to roll
115 static inline __u64 ror64(__u64 word, unsigned int shift)  in ror64()  argument
117 	return (word >> (shift & 63)) | (word << ((-shift) & 63));  in ror64()
121  * rol32 - rotate a 32-bit value left
123  * @shift: bits to roll
125 static inline __u32 rol32(__u32 word, unsigned int shift)  in rol32()  argument
127 	return (word << (shift & 31)) | (word >> ((-shift) & 31));  in rol32()
131  * ror32 - rotate a 32-bit value right
133  * @shift: bits to roll
135 static inline __u32 ror32(__u32 word, unsigned int shift)  in ror32()  argument
137 	return (word >> (shift & 31)) | (word << ((-shift) & 31));  in ror32()
141  * rol16 - rotate a 16-bit value left
143  * @shift: bits to roll
145 static inline __u16 rol16(__u16 word, unsigned int shift)  in rol16()  argument
147 	return (word << (shift & 15)) | (word >> ((-shift) & 15));  in rol16()
151  * ror16 - rotate a 16-bit value right
153  * @shift: bits to roll
155 static inline __u16 ror16(__u16 word, unsigned int shift)  in ror16()  argument
157 	return (word >> (shift & 15)) | (word << ((-shift) & 15));  in ror16()
161  * rol8 - rotate an 8-bit value left
163  * @shift: bits to roll
165 static inline __u8 rol8(__u8 word, unsigned int shift)  in rol8()  argument
167 	return (word << (shift & 7)) | (word >> ((-shift) & 7));  in rol8()
171  * ror8 - rotate an 8-bit value right
173  * @shift: bits to roll
175 static inline __u8 ror8(__u8 word, unsigned int shift)  in ror8()  argument
177 	return (word >> (shift & 7)) | (word << ((-shift) & 7));  in ror8()
181  * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
183  * @index: 0 based bit index (0<=index<32) to sign bit
185  * This is safe to use for 16- and 8-bit types as well.
189 	__u8 shift = 31 - index;  in sign_extend32()  local
190 	return (__s32)(value << shift) >> shift;  in sign_extend32()
194  * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
196  * @index: 0 based bit index (0<=index<64) to sign bit
200 	__u8 shift = 63 - index;  in sign_extend64()  local
201 	return (__s64)(value << shift) >> shift;  in sign_extend64()
214 		return -1;  in get_count_order()
216 	return fls(--count);  in get_count_order()
220  * get_count_order_long - get order after rounding @l up to power of 2
228 		return -1;  in get_count_order_long()
229 	return (int)fls_long(--l);  in get_count_order_long()
233  * parity8 - get the parity of an u8 value
245  *		return -EBADMSG;
247  * If you need to calculate a parity bit, you need to draw the conclusion from
248  * this result yourself. Example to enforce odd parity, parity bit is bit 7:
251  *		val ^= BIT(7);
264  * __ffs64 - find first set bit in a 64 bit word
265  * @word: The 64 bit word
267  * On 64 bit arches this is a synonym for __ffs
269  * is non-zero before calling this.
283  * fns - find N'th set bit in a word
285  * @n: Bit to find
289 	while (word && n--)  in fns()
290 		word &= word - 1;  in fns()
296  * assign_bit - Assign value to a bit in memory
297  * @nr: the bit to set
308  * __ptr_set_bit - Set bit in a pointer's value
309  * @nr: the bit to set
314  *	__ptr_set_bit(bit, &p);
323  * __ptr_clear_bit - Clear bit in a pointer's value
324  * @nr: the bit to clear
329  *	__ptr_clear_bit(bit, &p);
338  * __ptr_test_bit - Test bit in a pointer's value
339  * @nr: the bit to test
344  *	if (__ptr_test_bit(bit, &p)) {