[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v2 14/39] xen/riscv: introduce bitops.h
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx> --- Changes in V2: - Nothing changed. Only rebase. --- xen/arch/riscv/include/asm/bitops.h | 288 ++++++++++++++++++++++++++++ 1 file changed, 288 insertions(+) create mode 100644 xen/arch/riscv/include/asm/bitops.h diff --git a/xen/arch/riscv/include/asm/bitops.h b/xen/arch/riscv/include/asm/bitops.h new file mode 100644 index 0000000000..24a49c499b --- /dev/null +++ b/xen/arch/riscv/include/asm/bitops.h @@ -0,0 +1,288 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) 2012 Regents of the University of California */ + +#ifndef _ASM_RISCV_BITOPS_H +#define _ASM_RISCV_BITOPS_H + +#include <asm/system.h> + +#define BITOP_BITS_PER_WORD 32 +#define BITOP_MASK(nr) (1UL << ((nr) % BITOP_BITS_PER_WORD)) +#define BITOP_WORD(nr) ((nr) / BITOP_BITS_PER_WORD) +#define BITS_PER_BYTE 8 + +#define __set_bit(n,p) set_bit(n,p) +#define __clear_bit(n,p) clear_bit(n,p) + +#define __AMO(op) "amo" #op ".w" + +#define __test_and_op_bit_ord(op, mod, nr, addr, ord) \ +({ \ + unsigned long __res, __mask; \ + __mask = BITOP_MASK(nr); \ + __asm__ __volatile__ ( \ + __AMO(op) #ord " %0, %2, %1" \ + : "=r" (__res), "+A" (addr[BITOP_WORD(nr)]) \ + : "r" (mod(__mask)) \ + : "memory"); \ + ((__res & __mask) != 0); \ +}) + +#define __op_bit_ord(op, mod, nr, addr, ord) \ + __asm__ __volatile__ ( \ + __AMO(op) #ord " zero, %1, %0" \ + : "+A" (addr[BITOP_WORD(nr)]) \ + : "r" (mod(BITOP_MASK(nr))) \ + : "memory"); + +#define __test_and_op_bit(op, mod, nr, addr) \ + __test_and_op_bit_ord(op, mod, nr, addr, .aqrl) + +#define __op_bit(op, mod, nr, addr) \ + __op_bit_ord(op, mod, nr, addr, ) + +/* Bitmask modifiers */ +#define __NOP(x) (x) +#define __NOT(x) (~(x)) + +/** + * __test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation may be reordered on other architectures than x86. + */ +static inline int __test_and_set_bit(int nr, volatile void *p) +{ + volatile uint32_t *addr = p; + + return __test_and_op_bit(or, __NOP, nr, addr); +} + +/** + * __test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This operation can be reordered on other architectures other than x86. + */ +static inline int __test_and_clear_bit(int nr, volatile void *p) +{ + volatile uint32_t *addr = p; + + return __test_and_op_bit(and, __NOT, nr, addr); +} + +/** + * set_bit - Atomically set a bit in memory + * @nr: the bit to set + * @addr: the address to start counting from + * + * Note: there are no guarantees that this function will not be reordered + * on non x86 architectures, so if you are writing portable code, + * make sure not to rely on its reordering guarantees. + * + * Note that @nr may be almost arbitrarily large; this function is not + * restricted to acting on a single-word quantity. + */ +static inline void set_bit(int nr, volatile void *p) +{ + volatile uint32_t *addr = p; + + __op_bit(or, __NOP, nr, addr); +} + +/** + * clear_bit - Clears a bit in memory + * @nr: Bit to clear + * @addr: Address to start counting from + * + * Note: there are no guarantees that this function will not be reordered + * on non x86 architectures, so if you are writing portable code, + * make sure not to rely on its reordering guarantees. + */ +static inline void clear_bit(int nr, volatile void *p) +{ + volatile uint32_t *addr = p; + + __op_bit(and, __NOT, nr, addr); +} + +static inline int test_bit(int nr, const volatile void *p) +{ + const volatile uint32_t *addr = (const volatile uint32_t *)p; + + return 1UL & (addr[BITOP_WORD(nr)] >> (nr & (BITOP_BITS_PER_WORD-1))); +} + +#undef __test_and_op_bit +#undef __op_bit +#undef __NOP +#undef __NOT +#undef __AMO + +static inline int fls(unsigned int x) +{ + return generic_fls(x); +} + +static inline int flsl(unsigned long x) +{ + return generic_flsl(x); +} + +#define test_and_set_bit __test_and_set_bit +#define test_and_clear_bit __test_and_clear_bit + +/* Based on linux/include/asm-generic/bitops/find.h */ + +#ifndef find_next_bit +/** + * find_next_bit - find the next set bit in a memory region + * @addr: The address to base the search on + * @offset: The bitnumber to start searching at + * @size: The bitmap size in bits + */ +extern unsigned long find_next_bit(const unsigned long *addr, unsigned long + size, unsigned long offset); +#endif + +#ifndef find_next_zero_bit +/** + * find_next_zero_bit - find the next cleared bit in a memory region + * @addr: The address to base the search on + * @offset: The bitnumber to start searching at + * @size: The bitmap size in bits + */ +extern unsigned long find_next_zero_bit(const unsigned long *addr, unsigned + long size, unsigned long offset); +#endif + +/** + * find_first_bit - find the first set bit in a memory region + * @addr: The address to start the search at + * @size: The maximum size to search + * + * Returns the bit number of the first set bit. + */ +extern unsigned long find_first_bit(const unsigned long *addr, + unsigned long size); + +/** + * find_first_zero_bit - find the first cleared bit in a memory region + * @addr: The address to start the search at + * @size: The maximum size to search + * + * Returns the bit number of the first cleared bit. + */ +extern unsigned long find_first_zero_bit(const unsigned long *addr, + unsigned long size); + +#define ffs(x) ({ unsigned int __t = (x); fls(__t & -__t); }) + +/** + * ffs - find first bit in word. + * @word: The word to search + * + * Returns 0 if no bit exists, otherwise returns 1-indexed bit location. + */ +static inline unsigned long __ffs(unsigned long word) +{ + int num = 0; + +#if BITS_PER_LONG == 64 + if ((word & 0xffffffff) == 0) { + num += 32; + word >>= 32; + } +#endif + if ((word & 0xffff) == 0) { + num += 16; + word >>= 16; + } + if ((word & 0xff) == 0) { + num += 8; + word >>= 8; + } + if ((word & 0xf) == 0) { + num += 4; + word >>= 4; + } + if ((word & 0x3) == 0) { + num += 2; + word >>= 2; + } + if ((word & 0x1) == 0) + num += 1; + return num; +} + +/** + * ffsl - find first bit in long. + * @word: The word to search + * + * Returns 0 if no bit exists, otherwise returns 1-indexed bit location. + */ +static inline unsigned int ffsl(unsigned long word) +{ + int num = 1; + + if (!word) + return 0; + +#if BITS_PER_LONG == 64 + if ((word & 0xffffffff) == 0) { + num += 32; + word >>= 32; + } +#endif + if ((word & 0xffff) == 0) { + num += 16; + word >>= 16; + } + if ((word & 0xff) == 0) { + num += 8; + word >>= 8; + } + if ((word & 0xf) == 0) { + num += 4; + word >>= 4; + } + if ((word & 0x3) == 0) { + num += 2; + word >>= 2; + } + if ((word & 0x1) == 0) + num += 1; + return num; +} + +/* + * ffz - find first zero in word. + * @word: The word to search + * + * Undefined if no zero exists, so code should check against ~0UL first. + */ +#define ffz(x) __ffs(~(x)) + +/** + * find_first_set_bit - find the first set bit in @word + * @word: the word to search + * + * Returns the bit-number of the first set bit (first bit being 0). + * The input must *not* be zero. + */ +static inline unsigned int find_first_set_bit(unsigned long word) +{ + return ffsl(word) - 1; +} + +/** + * hweightN - returns the hamming weight of a N-bit word + * @x: the word to weigh + * + * The Hamming Weight of a number is the total number of bits set in it. + */ +#define hweight64(x) generic_hweight64(x) + +#endif /* _ASM_RISCV_BITOPS_H */ -- 2.42.0
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