1235783Skib/** 2235783Skib * \file drm_atomic.h 3235783Skib * Atomic operations used in the DRM which may or may not be provided by the OS. 4235783Skib * 5235783Skib * \author Eric Anholt <anholt@FreeBSD.org> 6235783Skib */ 7235783Skib 8235783Skib/*- 9235783Skib * Copyright 2004 Eric Anholt 10255041Sjkim * Copyright 2013 Jung-uk Kim <jkim@FreeBSD.org> 11235783Skib * All Rights Reserved. 12235783Skib * 13235783Skib * Permission is hereby granted, free of charge, to any person obtaining a 14235783Skib * copy of this software and associated documentation files (the "Software"), 15235783Skib * to deal in the Software without restriction, including without limitation 16235783Skib * the rights to use, copy, modify, merge, publish, distribute, sublicense, 17235783Skib * and/or sell copies of the Software, and to permit persons to whom the 18235783Skib * Software is furnished to do so, subject to the following conditions: 19235783Skib * 20235783Skib * The above copyright notice and this permission notice (including the next 21235783Skib * paragraph) shall be included in all copies or substantial portions of the 22235783Skib * Software. 23235783Skib * 24235783Skib * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 25235783Skib * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 26235783Skib * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 27235783Skib * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 28235783Skib * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 29235783Skib * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 30235783Skib * OTHER DEALINGS IN THE SOFTWARE. 31235783Skib */ 32235783Skib 33235783Skib#include <sys/cdefs.h> 34235783Skib__FBSDID("$FreeBSD$"); 35235783Skib 36255041Sjkimtypedef u_int atomic_t; 37254860Sdumbbelltypedef uint64_t atomic64_t; 38235783Skib 39282199Sdumbbell#define NB_BITS_PER_LONG (sizeof(long) * NBBY) 40282199Sdumbbell#define BITS_TO_LONGS(x) howmany(x, NB_BITS_PER_LONG) 41235783Skib 42255039Sjkim#define atomic_read(p) (*(volatile u_int *)(p)) 43255039Sjkim#define atomic_set(p, v) do { *(u_int *)(p) = (v); } while (0) 44235783Skib 45282199Sdumbbell#define atomic64_read(p) atomic_load_acq_64(p) 46282199Sdumbbell#define atomic64_set(p, v) atomic_store_rel_64(p, v) 47282199Sdumbbell 48254860Sdumbbell#define atomic_add(v, p) atomic_add_int(p, v) 49254860Sdumbbell#define atomic_sub(v, p) atomic_subtract_int(p, v) 50254860Sdumbbell#define atomic_inc(p) atomic_add(1, p) 51254860Sdumbbell#define atomic_dec(p) atomic_sub(1, p) 52235783Skib 53254860Sdumbbell#define atomic_add_return(v, p) (atomic_fetchadd_int(p, v) + (v)) 54254860Sdumbbell#define atomic_sub_return(v, p) (atomic_fetchadd_int(p, -(v)) - (v)) 55254860Sdumbbell#define atomic_inc_return(p) atomic_add_return(1, p) 56254860Sdumbbell#define atomic_dec_return(p) atomic_sub_return(1, p) 57235783Skib 58254860Sdumbbell#define atomic_add_and_test(v, p) (atomic_add_return(v, p) == 0) 59254860Sdumbbell#define atomic_sub_and_test(v, p) (atomic_sub_return(v, p) == 0) 60254860Sdumbbell#define atomic_inc_and_test(p) (atomic_inc_return(p) == 0) 61254860Sdumbbell#define atomic_dec_and_test(p) (atomic_dec_return(p) == 0) 62235783Skib 63254860Sdumbbell#define atomic_xchg(p, v) atomic_swap_int(p, v) 64254860Sdumbbell#define atomic64_xchg(p, v) atomic_swap_64(p, v) 65235783Skib 66282199Sdumbbell#define __bit_word(b) ((b) / NB_BITS_PER_LONG) 67282199Sdumbbell#define __bit_mask(b) (1UL << (b) % NB_BITS_PER_LONG) 68255041Sjkim#define __bit_addr(p, b) ((volatile u_long *)(p) + __bit_word(b)) 69255041Sjkim 70254860Sdumbbell#define clear_bit(b, p) \ 71255041Sjkim atomic_clear_long(__bit_addr(p, b), __bit_mask(b)) 72254860Sdumbbell#define set_bit(b, p) \ 73255041Sjkim atomic_set_long(__bit_addr(p, b), __bit_mask(b)) 74254860Sdumbbell#define test_bit(b, p) \ 75255042Sjkim ((*__bit_addr(p, b) & __bit_mask(b)) != 0) 76282199Sdumbbell#define test_and_set_bit(b, p) \ 77282199Sdumbbell (atomic_xchg((p), 1) != b) 78282199Sdumbbell#define cmpxchg(ptr, old, new) \ 79282199Sdumbbell (atomic_cmpset_int((volatile u_int *)(ptr),(old),(new)) ? (old) : (0)) 80254860Sdumbbell 81255041Sjkimstatic __inline u_long 82255041Sjkimfind_first_zero_bit(const u_long *p, u_long max) 83235783Skib{ 84255041Sjkim u_long i, n; 85235783Skib 86282199Sdumbbell KASSERT(max % NB_BITS_PER_LONG == 0, ("invalid bitmap size %lu", max)); 87282199Sdumbbell for (i = 0; i < max / NB_BITS_PER_LONG; i++) { 88255041Sjkim n = ~p[i]; 89254860Sdumbbell if (n != 0) 90282199Sdumbbell return (i * NB_BITS_PER_LONG + ffsl(n) - 1); 91235783Skib } 92254860Sdumbbell return (max); 93235783Skib} 94