/** * \file drm_atomic.h * Atomic operations used in the DRM which may or may not be provided by the OS. * * \author Eric Anholt */ /*- * Copyright 2004 Eric Anholt * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ /* Many of these implementations are rather fake, but good enough. */ typedef u_int32_t atomic_t; #ifdef __FreeBSD__ #define atomic_set(p, v) (*(p) = (v)) #define atomic_read(p) (*(p)) #define atomic_inc(p) atomic_add_int(p, 1) #define atomic_dec(p) atomic_subtract_int(p, 1) #define atomic_add(n, p) atomic_add_int(p, n) #define atomic_sub(n, p) atomic_subtract_int(p, n) #else /* __FreeBSD__ */ /* FIXME */ #define atomic_set(p, v) (*(p) = (v)) #define atomic_read(p) (*(p)) #define atomic_inc(p) (*(p) += 1) #define atomic_dec(p) (*(p) -= 1) #define atomic_add(n, p) (*(p) += (n)) #define atomic_sub(n, p) (*(p) -= (n)) /* FIXME */ #define atomic_add_int(p, v) *(p) += v #define atomic_subtract_int(p, v) *(p) -= v #define atomic_set_int(p, bits) *(p) |= (bits) #define atomic_clear_int(p, bits) *(p) &= ~(bits) #endif /* !__FreeBSD__ */ #if !defined(__FreeBSD_version) || (__FreeBSD_version < 500000) #if defined(__i386__) /* The extra atomic functions from 5.0 haven't been merged to 4.x */ static __inline int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src) { int res = exp; __asm __volatile ( " lock ; " " cmpxchgl %1,%2 ; " " setz %%al ; " " movzbl %%al,%0 ; " "1: " "# atomic_cmpset_int" : "+a" (res) /* 0 (result) */ : "r" (src), /* 1 */ "m" (*(dst)) /* 2 */ : "memory"); return (res); } #else /* __i386__ */ static __inline int atomic_cmpset_int(__volatile__ int *dst, int old, int new) { int s = splhigh(); if (*dst==old) { *dst = new; splx(s); return 1; } splx(s); return 0; } #endif /* !__i386__ */ #endif /* !__FreeBSD_version || __FreeBSD_version < 500000 */ static __inline atomic_t test_and_set_bit(int b, volatile void *p) { int s = splhigh(); unsigned int m = 1<> 5), 1 << (b & 0x1f)); } static __inline void set_bit(int b, volatile void *p) { atomic_set_int(((volatile int *)p) + (b >> 5), 1 << (b & 0x1f)); } static __inline int test_bit(int b, volatile void *p) { return ((volatile int *)p)[b >> 5] & (1 << (b & 0x1f)); } static __inline int find_first_zero_bit(volatile void *p, int max) { int b; volatile int *ptr = (volatile int *)p; for (b = 0; b < max; b += 32) { if (ptr[b >> 5] != ~0) { for (;;) { if ((ptr[b >> 5] & (1 << (b & 0x1f))) == 0) return b; b++; } } } return max; }