/*- * 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 #include /** * * 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 /** * * fls32 - 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: * fls32 (0x0) = INVALID_BIT_INDEX * fls32 (0x01) = 0 * fls32 (0x80) = 7 * ... * fls32 (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 fls32(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 uint16_t fls64(uint64_t value) { uint64_t ret = 0UL; if (value == 0UL) { ret = (INVALID_BIT_INDEX); } else { asm volatile("bsrq %1,%0" : "=r" (ret) : "rm" (value)); } return (uint16_t)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 INVALID_BIT_INDEX means that the return value is the inalid * bit index when the input argument was zero. * * Examples: * ffs64 (0x0) = INVALID_BIT_INDEX * ffs64 (0x01) = 0 * ffs64 (0xf0) = 4 * ffs64 (0xf00) = 8 * ... * ffs64 (0x8000000000000001) = 0 * ffs64 (0xf000000000000000) = 60 * * @param value: 'uint64_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 ffs64(uint64_t value) { uint64_t ret = 0UL; if (value == 0UL) { return (INVALID_BIT_INDEX); } asm volatile("bsfq %1,%0" : "=r" (ret) : "rm" (value)); return (uint16_t)ret; } /*bit scan forward for the least significant bit '0'*/ static inline uint16_t ffz64(uint64_t value) { return ffs64(~value); } /* * find the first zero bit in a uint64_t array. * @pre: the size must be multiple of 64. */ static inline uint64_t ffz64_ex(const uint64_t *addr, uint64_t size) { uint64_t idx; for (idx = 0UL; (idx << 6U) < size; idx++) { if (addr[idx] != ~0UL) { return (idx << 6U) + ffz64(addr[idx]); } } return size; } /** * 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 - fls32(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 uint16_t clz64(uint64_t value) { if (value == 0UL) { return 64U; } else { return (63U - fls64(value)); } } /* * (*addr) |= (1UL<=64, it will be truncated. */ #define build_bitmap_set(name, op_len, op_type, lock) \ static inline void name(uint16_t nr_arg, volatile op_type *addr) \ { \ uint16_t nr; \ nr = nr_arg & ((8U * sizeof(op_type)) - 1U); \ asm volatile(lock "or" op_len " %1,%0" \ : "+m" (*addr) \ : "r" ((op_type)(1UL<=64, it will be truncated. */ #define build_bitmap_clear(name, op_len, op_type, lock) \ static inline void name(uint16_t nr_arg, volatile op_type *addr) \ { \ uint16_t nr; \ nr = nr_arg & ((8U * sizeof(op_type)) - 1U); \ asm volatile(lock "and" op_len " %1,%0" \ : "+m" (*addr) \ : "r" ((op_type)(~(1UL<<(nr)))) \ : "cc", "memory"); \ } build_bitmap_clear(bitmap_clear_nolock, "q", uint64_t, "") build_bitmap_clear(bitmap_clear_lock, "q", uint64_t, BUS_LOCK) build_bitmap_clear(bitmap32_clear_nolock, "l", uint32_t, "") build_bitmap_clear(bitmap32_clear_lock, "l", uint32_t, BUS_LOCK) /* * return !!((*addr) & (1UL<=64, it will * be truncated. */ static inline bool bitmap_test(uint16_t nr_arg, const volatile uint64_t *addr) { uint16_t nr; int32_t ret = 0; nr = nr_arg & 0x3fU; asm volatile("btq %q2,%1\n\tsbbl %0, %0" : "=r" (ret) : "m" (*addr), "r" ((uint64_t)nr) : "cc", "memory"); return (ret != 0); } static inline bool bitmap32_test(uint16_t nr_arg, const volatile uint32_t *addr) { uint16_t nr; int32_t ret = 0; nr = nr_arg & 0x1fU; asm volatile("btl %2,%1\n\tsbbl %0, %0" : "=r" (ret) : "m" (*addr), "r" ((uint32_t)nr) : "cc", "memory"); return (ret != 0); } /* * bool ret = (*addr) & (1UL<=64, it * will be truncated. */ #define build_bitmap_testandset(name, op_len, op_type, lock) \ static inline bool name(uint16_t nr_arg, volatile op_type *addr) \ { \ uint16_t nr; \ int32_t ret=0; \ nr = nr_arg & ((8U * sizeof(op_type)) - 1U); \ asm volatile(lock "bts" op_len " %2,%1\n\tsbbl %0,%0" \ : "=r" (ret), "=m" (*addr) \ : "r" ((op_type)nr) \ : "cc", "memory"); \ return (ret != 0); \ } build_bitmap_testandset(bitmap_test_and_set_nolock, "q", uint64_t, "") build_bitmap_testandset(bitmap_test_and_set_lock, "q", uint64_t, BUS_LOCK) build_bitmap_testandset(bitmap32_test_and_set_nolock, "l", uint32_t, "") build_bitmap_testandset(bitmap32_test_and_set_lock, "l", uint32_t, BUS_LOCK) /* * bool ret = (*addr) & (1UL<=64, * it will be truncated. */ #define build_bitmap_testandclear(name, op_len, op_type, lock) \ static inline bool name(uint16_t nr_arg, volatile op_type *addr) \ { \ uint16_t nr; \ int32_t ret=0; \ nr = nr_arg & ((8U * sizeof(op_type)) - 1U); \ asm volatile(lock "btr" op_len " %2,%1\n\tsbbl %0,%0" \ : "=r" (ret), "=m" (*addr) \ : "r" ((op_type)nr) \ : "cc", "memory"); \ return (ret != 0); \ } build_bitmap_testandclear(bitmap_test_and_clear_nolock, "q", uint64_t, "") build_bitmap_testandclear(bitmap_test_and_clear_lock, "q", uint64_t, BUS_LOCK) build_bitmap_testandclear(bitmap32_test_and_clear_nolock, "l", uint32_t, "") build_bitmap_testandclear(bitmap32_test_and_clear_lock, "l", uint32_t, BUS_LOCK) #endif /* BITS_H*/