[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v4 09/30] xen/riscv: introduce bitops.h
Taken from Linux-6.4.0-rc1 Xen's bitops.h consists of several Linux's headers: * linux/arch/include/asm/bitops.h: * The following function were removed as they aren't used in Xen: * test_and_set_bit_lock * clear_bit_unlock * __clear_bit_unlock * The following functions were renamed in the way how they are used by common code: * __test_and_set_bit * __test_and_clear_bit * The declaration and implementation of the following functios were updated to make Xen build happy: * clear_bit * set_bit * __test_and_clear_bit * __test_and_set_bit * linux/arch/include/linux/bits.h ( taken only definitions for BIT_MASK, BIT_WORD, BITS_PER_BYTE ) * linux/include/asm-generic/bitops/generic-non-atomic.h with the following changes: * Only functions that can be reused in Xen were left; others were removed. * it was updated the message inside #ifndef ... #endif. * __always_inline -> always_inline to be align with definition in xen/compiler.h. * update function prototypes from generic___test_and_*(unsigned long nr nr, volatile unsigned long *addr) to generic___test_and_*(unsigned long nr, volatile void *addr) to be consistent with other related macros/defines. * convert identations from tabs to spaces. * inside generic__test_and_* use 'bitops_uint_t' instead of 'unsigned long' to be generic. Additionaly, the following bit ops are introduced: * __ffs * ffsl * fls * flsl * ffs * ffz * find_first_bit_set * hweight64 * test_bit Some of the introduced bit operations are included in asm-generic, as they exhibit similarity across multiple architectures. Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx> --- Changes in V4: - updated the commit message: dropped the message about what was taken from linux/include/asm-generic/bitops/find.h as related changes now are located in xen/bitops.h. Also these changes were removed from riscv/bitops.h - switch tabs to spaces. - update return type of __ffs function, format __ffs according to Xen code style. Move the function to respective asm-generic header. - format ffsl() according to Xen code style, update the type of num: int -> unsigned to be align with return type of the function. Move the function to respective asm-generic header. - add new line for the files: asm-generic/bitops-bits.h asm-generic/ffz.h asm-generic/find-first-bit-set.h asm-generic/fls.h asm-generic/flsl.h asm-generic/test-bit.h - rename asm-generic/find-first-bit-set.h to asm-generic/find-first-set-bit.h to be aligned with the function name implemented inside. - introduce generic___test_and*() operation for non-atomic bitops. - rename current __test_and_*() -> test_and_*() as their implementation are atomic aware. - define __test_and_*() to generic___test_and_*(). - introduce test_and_change_bit(). - update asm-generic/bitops/bitops-bits.h to give possoibility to change BITOP_*() macros by architecture. Also, it was introduced bitops_uint_t type to make generic___test_and_*() generic. - "include asm-generic/bitops/bitops-bits.h" to files which use its definitions. - add comment why generic ffz is defined as __ffs(). - update the commit message. - swtich ffsl() to generic_ffsl(). --- Changes in V3: - update the commit message - Introduce the following asm-generic bitops headers: create mode 100644 xen/arch/riscv/include/asm/bitops.h create mode 100644 xen/include/asm-generic/bitops/bitops-bits.h create mode 100644 xen/include/asm-generic/bitops/ffs.h create mode 100644 xen/include/asm-generic/bitops/ffz.h create mode 100644 xen/include/asm-generic/bitops/find-first-bit-set.h create mode 100644 xen/include/asm-generic/bitops/fls.h create mode 100644 xen/include/asm-generic/bitops/flsl.h create mode 100644 xen/include/asm-generic/bitops/hweight.h create mode 100644 xen/include/asm-generic/bitops/test-bit.h - switch some bitops functions to asm-generic's versions. - re-sync some macros with Linux kernel version mentioned in the commit message. - Xen code style fixes. --- Changes in V2: - Nothing changed. Only rebase. --- xen/arch/riscv/include/asm/bitops.h | 164 ++++++++++++++++++ xen/arch/riscv/include/asm/config.h | 2 + xen/include/asm-generic/bitops/__ffs.h | 47 +++++ xen/include/asm-generic/bitops/bitops-bits.h | 21 +++ xen/include/asm-generic/bitops/ffs.h | 9 + xen/include/asm-generic/bitops/ffsl.h | 16 ++ xen/include/asm-generic/bitops/ffz.h | 18 ++ .../asm-generic/bitops/find-first-set-bit.h | 17 ++ xen/include/asm-generic/bitops/fls.h | 18 ++ xen/include/asm-generic/bitops/flsl.h | 10 ++ .../asm-generic/bitops/generic-non-atomic.h | 89 ++++++++++ xen/include/asm-generic/bitops/hweight.h | 13 ++ xen/include/asm-generic/bitops/test-bit.h | 18 ++ 13 files changed, 442 insertions(+) create mode 100644 xen/arch/riscv/include/asm/bitops.h create mode 100644 xen/include/asm-generic/bitops/__ffs.h create mode 100644 xen/include/asm-generic/bitops/bitops-bits.h create mode 100644 xen/include/asm-generic/bitops/ffs.h create mode 100644 xen/include/asm-generic/bitops/ffsl.h create mode 100644 xen/include/asm-generic/bitops/ffz.h create mode 100644 xen/include/asm-generic/bitops/find-first-set-bit.h create mode 100644 xen/include/asm-generic/bitops/fls.h create mode 100644 xen/include/asm-generic/bitops/flsl.h create mode 100644 xen/include/asm-generic/bitops/generic-non-atomic.h create mode 100644 xen/include/asm-generic/bitops/hweight.h create mode 100644 xen/include/asm-generic/bitops/test-bit.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..1225298d35 --- /dev/null +++ b/xen/arch/riscv/include/asm/bitops.h @@ -0,0 +1,164 @@ +/* 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> + +#include <asm-generic/bitops/bitops-bits.h> + +/* Based on linux/arch/include/linux/bits.h */ + +#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) +#define BIT_WORD(nr) ((nr) / BITS_PER_LONG) + +#define __set_bit(n,p) set_bit(n,p) +#define __clear_bit(n,p) clear_bit(n,p) + +/* Based on linux/arch/include/asm/bitops.h */ + +#if ( BITS_PER_LONG == 64 ) +#define __AMO(op) "amo" #op ".d" +#elif ( BITS_PER_LONG == 32 ) +#define __AMO(op) "amo" #op ".w" +#else +#error "Unexpected BITS_PER_LONG" +#endif + +#define __test_and_op_bit_ord(op, mod, nr, addr, ord) \ +({ \ + unsigned long __res, __mask; \ + __mask = BIT_MASK(nr); \ + __asm__ __volatile__ ( \ + __AMO(op) #ord " %0, %2, %1" \ + : "=r" (__res), "+A" (addr[BIT_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[BIT_WORD(nr)]) \ + : "r" (mod(BIT_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); +} + +/** + * test_and_change_bit - Change a bit and return its old value + * @nr: Bit to change + * @addr: Address to count from + * + * This operation is atomic and cannot be reordered. + * It also implies a memory barrier. + */ +static inline int test_and_change_bit(int nr, volatile unsigned long *addr) +{ + return __test_and_op_bit(xor, __NOP, nr, addr); +} + +#undef __test_and_op_bit +#undef __op_bit +#undef __NOP +#undef __NOT +#undef __AMO + +#include <asm-generic/bitops/generic-non-atomic.h> + +#define __test_and_set_bit generic___test_and_set_bit +#define __test_and_clear_bit generic___test_and_clear_bit +#define __test_and_change_bit generic___test_and_change_bit + +#include <asm-generic/bitops/fls.h> +#include <asm-generic/bitops/flsl.h> +#include <asm-generic/bitops/__ffs.h> +#include <asm-generic/bitops/ffs.h> +#include <asm-generic/bitops/ffsl.h> +#include <asm-generic/bitops/ffz.h> +#include <asm-generic/bitops/find-first-set-bit.h> +#include <asm-generic/bitops/hweight.h> +#include <asm-generic/bitops/test-bit.h> + +#endif /* _ASM_RISCV_BITOPS_H */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/arch/riscv/include/asm/config.h b/xen/arch/riscv/include/asm/config.h index a80cdd4f85..56387ac159 100644 --- a/xen/arch/riscv/include/asm/config.h +++ b/xen/arch/riscv/include/asm/config.h @@ -50,6 +50,8 @@ # error "Unsupported RISCV variant" #endif +#define BITS_PER_BYTE 8 + #define BYTES_PER_LONG (1 << LONG_BYTEORDER) #define BITS_PER_LONG (BYTES_PER_LONG << 3) #define POINTER_ALIGN BYTES_PER_LONG diff --git a/xen/include/asm-generic/bitops/__ffs.h b/xen/include/asm-generic/bitops/__ffs.h new file mode 100644 index 0000000000..fecb4484d9 --- /dev/null +++ b/xen/include/asm-generic/bitops/__ffs.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS___FFS_H_ +#define _ASM_GENERIC_BITOPS___FFS_H_ + +/** + * 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 int __ffs(unsigned long word) +{ + unsigned 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; +} + +#endif /* _ASM_GENERIC_BITOPS___FFS_H_ */ diff --git a/xen/include/asm-generic/bitops/bitops-bits.h b/xen/include/asm-generic/bitops/bitops-bits.h new file mode 100644 index 0000000000..4ece2affd6 --- /dev/null +++ b/xen/include/asm-generic/bitops/bitops-bits.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_BITS_H_ +#define _ASM_GENERIC_BITOPS_BITS_H_ + +#ifndef BITOP_BITS_PER_WORD +#define BITOP_BITS_PER_WORD 32 +#endif + +#ifndef BITOP_MASK +#define BITOP_MASK(nr) (1U << ((nr) % BITOP_BITS_PER_WORD)) +#endif + +#ifndef BITOP_WORD +#define BITOP_WORD(nr) ((nr) / BITOP_BITS_PER_WORD) +#endif + +#ifndef BITOP_TYPE +typedef uint32_t bitops_uint_t; +#endif + +#endif /* _ASM_GENERIC_BITOPS_BITS_H_ */ diff --git a/xen/include/asm-generic/bitops/ffs.h b/xen/include/asm-generic/bitops/ffs.h new file mode 100644 index 0000000000..3f75fded14 --- /dev/null +++ b/xen/include/asm-generic/bitops/ffs.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FFS_H_ +#define _ASM_GENERIC_BITOPS_FFS_H_ + +#include <xen/macros.h> + +#define ffs(x) ({ unsigned int t_ = (x); fls(ISOLATE_LSB(t_)); }) + +#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */ diff --git a/xen/include/asm-generic/bitops/ffsl.h b/xen/include/asm-generic/bitops/ffsl.h new file mode 100644 index 0000000000..d0996808f5 --- /dev/null +++ b/xen/include/asm-generic/bitops/ffsl.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FFSL_H_ +#define _ASM_GENERIC_BITOPS_FFSL_H_ + +/** + * 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) +{ + return generic_ffsl(word); +} + +#endif /* _ASM_GENERIC_BITOPS_FFSL_H_ */ diff --git a/xen/include/asm-generic/bitops/ffz.h b/xen/include/asm-generic/bitops/ffz.h new file mode 100644 index 0000000000..5932fe6695 --- /dev/null +++ b/xen/include/asm-generic/bitops/ffz.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FFZ_H_ +#define _ASM_GENERIC_BITOPS_FFZ_H_ + +/* + * ffz - find first zero in word. + * @word: The word to search + * + * Undefined if no zero exists, so code should check against ~0UL first. + * + * ffz() is defined as __ffs() and not as ffs() as it is defined in such + * a way in Linux kernel (6.4.0 ) from where this header was taken, so this + * header is supposed to be aligned with Linux kernel version. + * Also, most architectures are defined in the same way in Xen. + */ +#define ffz(x) __ffs(~(x)) + +#endif /* _ASM_GENERIC_BITOPS_FFZ_H_ */ diff --git a/xen/include/asm-generic/bitops/find-first-set-bit.h b/xen/include/asm-generic/bitops/find-first-set-bit.h new file mode 100644 index 0000000000..7d28b8a89b --- /dev/null +++ b/xen/include/asm-generic/bitops/find-first-set-bit.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FIND_FIRST_SET_BIT_H_ +#define _ASM_GENERIC_BITOPS_FIND_FIRST_SET_BIT_H_ + +/** + * 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; +} + +#endif /* _ASM_GENERIC_BITOPS_FIND_FIRST_SET_BIT_H_ */ diff --git a/xen/include/asm-generic/bitops/fls.h b/xen/include/asm-generic/bitops/fls.h new file mode 100644 index 0000000000..369a4c790c --- /dev/null +++ b/xen/include/asm-generic/bitops/fls.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FLS_H_ +#define _ASM_GENERIC_BITOPS_FLS_H_ + +/** + * fls - find last (most-significant) bit set + * @x: the word to search + * + * This is defined the same way as ffs. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ + +static inline int fls(unsigned int x) +{ + return generic_fls(x); +} + +#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ diff --git a/xen/include/asm-generic/bitops/flsl.h b/xen/include/asm-generic/bitops/flsl.h new file mode 100644 index 0000000000..d0a2e9c729 --- /dev/null +++ b/xen/include/asm-generic/bitops/flsl.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_FLSL_H_ +#define _ASM_GENERIC_BITOPS_FLSL_H_ + +static inline int flsl(unsigned long x) +{ + return generic_flsl(x); +} + +#endif /* _ASM_GENERIC_BITOPS_FLSL_H_ */ diff --git a/xen/include/asm-generic/bitops/generic-non-atomic.h b/xen/include/asm-generic/bitops/generic-non-atomic.h new file mode 100644 index 0000000000..07efca245e --- /dev/null +++ b/xen/include/asm-generic/bitops/generic-non-atomic.h @@ -0,0 +1,89 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * The file is based on Linux ( 6.4.0 ) header: + * include/asm-generic/bitops/generic-non-atomic.h + * + * Only functions that can be reused in Xen were left; others were removed. + * + * Also, the following changes were done: + * - it was updated the message inside #ifndef ... #endif. + * - __always_inline -> always_inline to be align with definition in + * xen/compiler.h. + * - update function prototypes from + * generic___test_and_*(unsigned long nr nr, volatile unsigned long *addr) to + * generic___test_and_*(unsigned long nr, volatile void *addr) to be + * consistent with other related macros/defines. + * - convert identations from tabs to spaces. + * - inside generic__test_and_* use 'bitops_uint_t' instead of 'unsigned long' + * to be generic. + */ + +#ifndef __ASM_GENERIC_BITOPS_GENERIC_NON_ATOMIC_H +#define __ASM_GENERIC_BITOPS_GENERIC_NON_ATOMIC_H + +#include <xen/compiler.h> + +#include <asm-generic/bitops/bitops-bits.h> + +#ifndef _LINUX_BITOPS_H +#error only <xen/bitops.h> can be included directly +#endif + +/* + * Generic definitions for bit operations, should not be used in regular code + * directly. + */ + +/** + * generic___test_and_set_bit - Set a bit and return its old value + * @nr: Bit to set + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * If two examples of this operation race, one can appear to succeed + * but actually fail. You must protect multiple accesses with a lock. + */ +static always_inline bool +generic___test_and_set_bit(unsigned long nr, volatile void *addr) +{ + bitops_uint_t mask = BIT_MASK(nr); + bitops_uint_t *p = ((bitops_uint_t *)addr) + BIT_WORD(nr); + bitops_uint_t old = *p; + + *p = old | mask; + return (old & mask) != 0; +} + +/** + * generic___test_and_clear_bit - Clear a bit and return its old value + * @nr: Bit to clear + * @addr: Address to count from + * + * This operation is non-atomic and can be reordered. + * If two examples of this operation race, one can appear to succeed + * but actually fail. You must protect multiple accesses with a lock. + */ +static always_inline bool +generic___test_and_clear_bit(bitops_uint_t nr, volatile void *addr) +{ + bitops_uint_t mask = BIT_MASK(nr); + bitops_uint_t *p = ((bitops_uint_t *)addr) + BIT_WORD(nr); + bitops_uint_t old = *p; + + *p = old & ~mask; + return (old & mask) != 0; +} + +/* WARNING: non atomic and it can be reordered! */ +static always_inline bool +generic___test_and_change_bit(unsigned long nr, volatile void *addr) +{ + bitops_uint_t mask = BIT_MASK(nr); + bitops_uint_t *p = ((bitops_uint_t *)addr) + BIT_WORD(nr); + bitops_uint_t old = *p; + + *p = old ^ mask; + return (old & mask) != 0; +} + +#endif /* __ASM_GENERIC_BITOPS_GENERIC_NON_ATOMIC_H */ diff --git a/xen/include/asm-generic/bitops/hweight.h b/xen/include/asm-generic/bitops/hweight.h new file mode 100644 index 0000000000..0d7577054e --- /dev/null +++ b/xen/include/asm-generic/bitops/hweight.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_HWEIGHT_H_ +#define _ASM_GENERIC_BITOPS_HWEIGHT_H_ + +/* + * 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_GENERIC_BITOPS_HWEIGHT_H_ */ diff --git a/xen/include/asm-generic/bitops/test-bit.h b/xen/include/asm-generic/bitops/test-bit.h new file mode 100644 index 0000000000..6fb414d808 --- /dev/null +++ b/xen/include/asm-generic/bitops/test-bit.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_GENERIC_BITOPS_TESTBIT_H_ +#define _ASM_GENERIC_BITOPS_TESTBIT_H_ + +#include <asm-generic/bitops/bitops-bits.h> + +/** + * test_bit - Determine whether a bit is set + * @nr: bit number to test + * @addr: Address to start counting from + */ +static inline int test_bit(int nr, const volatile void *addr) +{ + const volatile bitops_uint_t *p = addr; + return 1 & (p[BITOP_WORD(nr)] >> (nr & (BITOP_BITS_PER_WORD - 1))); +} + +#endif /* _ASM_GENERIC_BITOPS_TESTBIT_H_ */ -- 2.43.0
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