/*- * Copyright (c) 1998 Doug Rabson * Copyright (c) 2017 Intel Corporation * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD$ */ #ifndef BITS_H #define BITS_H #define BUS_LOCK "lock ; " /** * * INVALID_BIT_INDEX means when input paramter is zero, * bit operations function can't find bit set and return * the invalid bit index directly. * **/ #define INVALID_BIT_INDEX 0xffffU /** * * fls - Find the Last (most significant) bit Set in value and * return the bit index of that bit. * * Bits are numbered starting at 0,the least significant bit. * A return value of INVALID_BIT_INDEX means return value is * invalid bit index when the input argument was zero. * * Examples: * fls (0x0) = INVALID_BIT_INDEX * fls (0x01) = 0 * fls (0x80) = 7 * ... * fls (0x80000001) = 31 * * @param value: 'uint32_t' type value * * @return value: zero-based bit index, INVALID_BIT_INDEX means * when 'value' was zero, bit operations function can't find bit * set and return the invalid bit index directly. * * **/ static inline uint16_t fls(uint32_t value) { uint32_t ret = 0U; if (value == 0U) return (INVALID_BIT_INDEX); asm volatile("bsrl %1,%0" : "=r" (ret) : "rm" (value)); return (uint16_t)ret; } static inline int fls64(unsigned long value) { int ret; asm volatile("bsrq %1,%q0" : "=r" (ret) : "rm" (value), "0" (-1)); return ret; } /** * * ffs64 - Find the First (least significant) bit Set in value(Long type) * and return the index of that bit. * * Bits are numbered starting at 0,the least significant bit. * A return value of -1 means that the argument was zero. * * Examples: * ffs64 (0x0) = -1 * ffs64 (0x01) = 0 * ffs64 (0xf0) = 4 * ffs64 (0xf00) = 8 * ... * ffs64 (0x8000000000000001) = 0 * ffs64 (0xf000000000000000) = 60 * * @param value: 'unsigned long' type value * * @return value: zero-based bit index, -1 means 'value' was zero. * * **/ static inline int ffs64(unsigned long value) { int ret; asm volatile("bsfq %1,%q0" : "=r" (ret) : "rm" (value), "0" (-1)); return ret; } /*bit scan forward for the least significant bit '0'*/ static inline int ffz64(unsigned long value) { return ffs64(~value); } /** * Counts leading zeros. * * The number of leading zeros is defined as the number of * most significant bits which are not '1'. E.g.: * clz(0x80000000)==0 * clz(0x40000000)==1 * ... * clz(0x00000001)==31 * clz(0x00000000)==32 * * @param value:The 32 bit value to count the number of leading zeros. * * @return The number of leading zeros in 'value'. */ static inline uint16_t clz(uint32_t value) { if (value == 0U) return 32U; else{ return (31U - fls(value)); } } /** * Counts leading zeros (64 bit version). * * @param value:The 64 bit value to count the number of leading zeros. * * @return The number of leading zeros in 'value'. */ static inline int clz64(unsigned long value) { return (63 - fls64(value)); } /* * (*addr) |= (1UL<=64, it will be truncated. */ #define build_bitmap_set(name, lock, nr, addr) \ static inline void name(uint16_t nr, volatile uint64_t *addr) \ { \ nr = nr & 0x3fU; \ asm volatile(lock "orq %q1,%0" \ : "+m" (*addr) \ : "r" ((1UL<<(uint64_t)nr)) \ : "cc", "memory"); \ } build_bitmap_set(__bitmap_set, "", nr, addr) build_bitmap_set(bitmap_set, BUS_LOCK, nr, addr) /* * (*addr) &= ~(1UL<=64, it will be truncated. */ #define build_bitmap_clear(name, lock, nr, addr) \ static inline void name(uint16_t nr, volatile uint64_t *addr) \ { \ nr = nr & 0x3fU; \ asm volatile(lock "andq %q1,%0" \ : "+m" (*addr) \ : "r" ((~(1UL<<(uint64_t)nr))) \ : "cc", "memory"); \ } build_bitmap_clear(__bitmap_clear, "", nr, addr) build_bitmap_clear(bitmap_clear, BUS_LOCK, nr, addr) /* * return !!((*addr) & (1UL<=64, it will * be truncated. */ static inline bool bitmap_test(uint16_t nr, volatile uint64_t *addr) { int32_t ret=0; nr = nr & 0x3fU; asm volatile("btq %q2,%1\n\tsbbl %0, %0" : "=r" (ret), "=m" (*addr) : "r" ((uint64_t)nr) : "cc", "memory"); return (ret != 0); } /* * bool ret = (*addr) & (1UL<=64, it * will be truncated. */ #define build_bitmap_testandset(name, lock, nr, addr) \ static inline bool name(uint16_t nr, volatile uint64_t *addr) \ { \ int32_t ret=0; \ nr = nr & 0x3fU; \ asm volatile(lock "btsq %q2,%1\n\tsbbl %0,%0" \ : "=r" (ret), "=m" (*addr) \ : "r" ((uint64_t)nr) \ : "cc", "memory"); \ return (ret != 0); \ } build_bitmap_testandset(__bitmap_test_and_set, "", nr, addr) build_bitmap_testandset(bitmap_test_and_set, BUS_LOCK, nr, addr) /* * bool ret = (*addr) & (1UL<=64, * it will be truncated. */ #define build_bitmap_testandclear(name, lock, nr, addr) \ static inline bool name(uint16_t nr, volatile uint64_t *addr) \ { \ int32_t ret=0; \ nr = nr & 0x3fU; \ asm volatile(lock "btrq %q2,%1\n\tsbbl %0,%0" \ : "=r" (ret), "=m" (*addr) \ : "r" ((uint64_t)nr) \ : "cc", "memory"); \ return (ret != 0); \ } build_bitmap_testandclear(__bitmap_test_and_clear, "", nr, addr) build_bitmap_testandclear(bitmap_test_and_clear, BUS_LOCK, nr, addr) #endif /* BITS_H*/