/* SPDX-License-Identifier: GPL-2.0 */#ifndef __LINUX_BITS_H#define __LINUX_BITS_H #include <linux/const.h>#include <vdso/bits.h>#include <uapi/linux/bits.h>#include <asm/bitsperlong.h> #define BIT_MASK(nr)		(UL(1) << ((nr) % BITS_PER_LONG))#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)#define BIT_ULL_MASK(nr)	(ULL(1) << ((nr) % BITS_PER_LONG_LONG))#define BIT_ULL_WORD(nr)	((nr) / BITS_PER_LONG_LONG)#define BITS_PER_BYTE		8#define BITS_PER_TYPE(type)	(sizeof(type) * BITS_PER_BYTE) /* * Create a contiguous bitmask starting at bit position @l and ending at * position @h. For example * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. */#if !defined(__ASSEMBLY__) /* * Missing asm support * * GENMASK_U*() and BIT_U*() depend on BITS_PER_TYPE() which relies on sizeof(), * something not available in asm. Nevertheless, fixed width integers is a C * concept. Assembly code can rely on the long and long long versions instead. */ #include <linux/build_bug.h>#include <linux/compiler.h>#include <linux/overflow.h> #define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h))) /* * Generate a mask for the specified type @t. Additional checks are made to * guarantee the value returned fits in that type, relying on * -Wshift-count-overflow compiler check to detect incompatible arguments. * For example, all these create build errors or warnings: * * - GENMASK(15, 20): wrong argument order * - GENMASK(72, 15): doesn't fit unsigned long * - GENMASK_U32(33, 15): doesn't fit in a u32 */#define GENMASK_TYPE(t, h, l)					\	((t)(GENMASK_INPUT_CHECK(h, l) +			\	     (type_max(t) << (l) &				\	      type_max(t) >> (BITS_PER_TYPE(t) - 1 - (h))))) #define GENMASK_U8(h, l)	GENMASK_TYPE(u8, h, l)#define GENMASK_U16(h, l)	GENMASK_TYPE(u16, h, l)#define GENMASK_U32(h, l)	GENMASK_TYPE(u32, h, l)#define GENMASK_U64(h, l)	GENMASK_TYPE(u64, h, l) /* * Fixed-type variants of BIT(), with additional checks like GENMASK_TYPE(). The * following examples generate compiler warnings due to -Wshift-count-overflow: * * - BIT_U8(8) * - BIT_U32(-1) * - BIT_U32(40) */#define BIT_INPUT_CHECK(type, nr) \	BUILD_BUG_ON_ZERO(const_true((nr) >= BITS_PER_TYPE(type))) #define BIT_TYPE(type, nr) ((type)(BIT_INPUT_CHECK(type, nr) + BIT_ULL(nr))) #define BIT_U8(nr)	BIT_TYPE(u8, nr)#define BIT_U16(nr)	BIT_TYPE(u16, nr)#define BIT_U32(nr)	BIT_TYPE(u32, nr)#define BIT_U64(nr)	BIT_TYPE(u64, nr) #else /* defined(__ASSEMBLY__) */ /* * BUILD_BUG_ON_ZERO is not available in h files included from asm files, * disable the input check if that is the case. */#define GENMASK_INPUT_CHECK(h, l) 0 #endif /* !defined(__ASSEMBLY__) */ #define GENMASK(h, l) \	(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))#define GENMASK_ULL(h, l) \	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l)) #if !defined(__ASSEMBLY__)/* * Missing asm support * * __GENMASK_U128() depends on _BIT128() which would not work * in the asm code, as it shifts an 'unsigned __int128' data * type instead of direct representation of 128 bit constants * such as long and unsigned long. The fundamental problem is * that a 128 bit constant will get silently truncated by the * gcc compiler. */#define GENMASK_U128(h, l) \	(GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l))#endif #endif	/* __LINUX_BITS_H */