1145132Sanholt/** 2145132Sanholt * \file drm_atomic.h 3145132Sanholt * Atomic operations used in the DRM which may or may not be provided by the OS. 4145132Sanholt * 5145132Sanholt * \author Eric Anholt <anholt@FreeBSD.org> 6145132Sanholt */ 7145132Sanholt 8145132Sanholt/*- 9145132Sanholt * Copyright 2004 Eric Anholt 10145132Sanholt * All Rights Reserved. 11145132Sanholt * 12145132Sanholt * Permission is hereby granted, free of charge, to any person obtaining a 13145132Sanholt * copy of this software and associated documentation files (the "Software"), 14145132Sanholt * to deal in the Software without restriction, including without limitation 15145132Sanholt * the rights to use, copy, modify, merge, publish, distribute, sublicense, 16145132Sanholt * and/or sell copies of the Software, and to permit persons to whom the 17145132Sanholt * Software is furnished to do so, subject to the following conditions: 18145132Sanholt * 19145132Sanholt * The above copyright notice and this permission notice (including the next 20145132Sanholt * paragraph) shall be included in all copies or substantial portions of the 21145132Sanholt * Software. 22145132Sanholt * 23145132Sanholt * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 24145132Sanholt * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 25145132Sanholt * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 26145132Sanholt * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 27145132Sanholt * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 28145132Sanholt * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 29145132Sanholt * OTHER DEALINGS IN THE SOFTWARE. 30145132Sanholt */ 31145132Sanholt 32152909Sanholt#include <sys/cdefs.h> 33152909Sanholt__FBSDID("$FreeBSD: releng/10.3/sys/dev/drm/drm_atomic.h 183573 2008-10-03 16:59:11Z rnoland $"); 34152909Sanholt 35145132Sanholt/* Many of these implementations are rather fake, but good enough. */ 36145132Sanholt 37145132Sanholttypedef u_int32_t atomic_t; 38145132Sanholt 39145132Sanholt#define atomic_set(p, v) (*(p) = (v)) 40145132Sanholt#define atomic_read(p) (*(p)) 41145132Sanholt#define atomic_inc(p) atomic_add_int(p, 1) 42145132Sanholt#define atomic_dec(p) atomic_subtract_int(p, 1) 43145132Sanholt#define atomic_add(n, p) atomic_add_int(p, n) 44145132Sanholt#define atomic_sub(n, p) atomic_subtract_int(p, n) 45145132Sanholt 46145132Sanholtstatic __inline atomic_t 47145132Sanholttest_and_set_bit(int b, volatile void *p) 48145132Sanholt{ 49145132Sanholt int s = splhigh(); 50145132Sanholt unsigned int m = 1<<b; 51145132Sanholt unsigned int r = *(volatile int *)p & m; 52145132Sanholt *(volatile int *)p |= m; 53145132Sanholt splx(s); 54145132Sanholt return r; 55145132Sanholt} 56145132Sanholt 57145132Sanholtstatic __inline void 58145132Sanholtclear_bit(int b, volatile void *p) 59145132Sanholt{ 60145132Sanholt atomic_clear_int(((volatile int *)p) + (b >> 5), 1 << (b & 0x1f)); 61145132Sanholt} 62145132Sanholt 63145132Sanholtstatic __inline void 64145132Sanholtset_bit(int b, volatile void *p) 65145132Sanholt{ 66145132Sanholt atomic_set_int(((volatile int *)p) + (b >> 5), 1 << (b & 0x1f)); 67145132Sanholt} 68145132Sanholt 69145132Sanholtstatic __inline int 70145132Sanholttest_bit(int b, volatile void *p) 71145132Sanholt{ 72145132Sanholt return ((volatile int *)p)[b >> 5] & (1 << (b & 0x1f)); 73145132Sanholt} 74145132Sanholt 75145132Sanholtstatic __inline int 76145132Sanholtfind_first_zero_bit(volatile void *p, int max) 77145132Sanholt{ 78145132Sanholt int b; 79145132Sanholt volatile int *ptr = (volatile int *)p; 80145132Sanholt 81145132Sanholt for (b = 0; b < max; b += 32) { 82145132Sanholt if (ptr[b >> 5] != ~0) { 83145132Sanholt for (;;) { 84145132Sanholt if ((ptr[b >> 5] & (1 << (b & 0x1f))) == 0) 85145132Sanholt return b; 86145132Sanholt b++; 87145132Sanholt } 88145132Sanholt } 89145132Sanholt } 90145132Sanholt return max; 91145132Sanholt} 92