drm_wait_netbsd.h revision 1.5.2.2
1 /* $NetBSD: drm_wait_netbsd.h,v 1.5.2.2 2015/06/06 14:40:19 skrll Exp $ */ 2 3 /*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #ifndef _DRM_DRM_WAIT_NETBSD_H_ 33 #define _DRM_DRM_WAIT_NETBSD_H_ 34 35 #include <sys/param.h> 36 #include <sys/condvar.h> 37 #if DIAGNOSTIC 38 #include <sys/cpu.h> /* cpu_intr_p */ 39 #endif 40 #include <sys/kernel.h> 41 #include <sys/mutex.h> 42 #include <sys/systm.h> 43 44 #include <linux/mutex.h> 45 #include <linux/spinlock.h> 46 47 typedef kcondvar_t drm_waitqueue_t; 48 49 #define DRM_HZ hz /* XXX Hurk... */ 50 51 #define DRM_UDELAY DELAY 52 53 static inline void 54 DRM_INIT_WAITQUEUE(drm_waitqueue_t *q, const char *name) 55 { 56 cv_init(q, name); 57 } 58 59 static inline void 60 DRM_DESTROY_WAITQUEUE(drm_waitqueue_t *q) 61 { 62 cv_destroy(q); 63 } 64 65 static inline bool 66 DRM_WAITERS_P(drm_waitqueue_t *q, struct mutex *interlock) 67 { 68 KASSERT(mutex_is_locked(interlock)); 69 return cv_has_waiters(q); 70 } 71 72 static inline void 73 DRM_WAKEUP_ONE(drm_waitqueue_t *q, struct mutex *interlock) 74 { 75 KASSERT(mutex_is_locked(interlock)); 76 cv_signal(q); 77 } 78 79 static inline void 80 DRM_WAKEUP_ALL(drm_waitqueue_t *q, struct mutex *interlock) 81 { 82 KASSERT(mutex_is_locked(interlock)); 83 cv_broadcast(q); 84 } 85 86 static inline bool 87 DRM_SPIN_WAITERS_P(drm_waitqueue_t *q, spinlock_t *interlock) 88 { 89 KASSERT(spin_is_locked(interlock)); 90 return cv_has_waiters(q); 91 } 92 93 static inline void 94 DRM_SPIN_WAKEUP_ONE(drm_waitqueue_t *q, spinlock_t *interlock) 95 { 96 KASSERT(spin_is_locked(interlock)); 97 cv_signal(q); 98 } 99 100 static inline void 101 DRM_SPIN_WAKEUP_ALL(drm_waitqueue_t *q, spinlock_t *interlock) 102 { 103 KASSERT(spin_is_locked(interlock)); 104 cv_broadcast(q); 105 } 106 107 /* 108 * DRM_SPIN_WAIT_ON is a replacement for the legacy DRM_WAIT_ON 109 * portability macro. It requires a spin interlock, which may require 110 * changes to the surrounding code so that the waits actually are 111 * interlocked by a spin lock. It also polls the condition at every 112 * tick, which masks missing wakeups. Since DRM_WAIT_ON is going away, 113 * in favour of Linux's native wait_event* API, waits in new code 114 * should be written to use the DRM_*WAIT*_UNTIL macros below. 115 * 116 * Like the legacy DRM_WAIT_ON, DRM_SPIN_WAIT_ON returns 117 * 118 * . -EBUSY if timed out (yes, -EBUSY, not -ETIMEDOUT or -EWOULDBLOCK), 119 * . -EINTR/-ERESTART if interrupted by a signal, or 120 * . 0 if the condition was true before or just after the timeout. 121 * 122 * Note that cv_timedwait* return -EWOULDBLOCK, not -EBUSY, on timeout. 123 */ 124 125 #define DRM_SPIN_WAIT_ON(RET, Q, INTERLOCK, TICKS, CONDITION) do \ 126 { \ 127 unsigned _dswo_ticks = (TICKS); \ 128 unsigned _dswo_start, _dswo_end; \ 129 \ 130 KASSERT(spin_is_locked((INTERLOCK))); \ 131 KASSERT(!cpu_intr_p()); \ 132 KASSERT(!cpu_softintr_p()); \ 133 KASSERT(!cold); \ 134 \ 135 for (;;) { \ 136 if (CONDITION) { \ 137 (RET) = 0; \ 138 break; \ 139 } \ 140 if (_dswo_ticks == 0) { \ 141 (RET) = -EBUSY; /* Match Linux... */ \ 142 break; \ 143 } \ 144 _dswo_start = hardclock_ticks; \ 145 /* XXX errno NetBSD->Linux */ \ 146 (RET) = -cv_timedwait_sig((Q), &(INTERLOCK)->sl_lock, 1); \ 147 _dswo_end = hardclock_ticks; \ 148 if (_dswo_end - _dswo_start < _dswo_ticks) \ 149 _dswo_ticks -= _dswo_end - _dswo_start; \ 150 else \ 151 _dswo_ticks = 0; \ 152 if (RET) { \ 153 if ((RET) == -EWOULDBLOCK) \ 154 /* Waited only one tick. */ \ 155 continue; \ 156 break; \ 157 } \ 158 } \ 159 } while (0) 160 161 /* 162 * The DRM_*WAIT*_UNTIL macros are replacements for the Linux 163 * wait_event* macros. Like DRM_SPIN_WAIT_ON, they add an interlock, 164 * and so may require some changes to the surrounding code. They have 165 * a different return value convention from DRM_SPIN_WAIT_ON and a 166 * different return value convention from cv_*wait*. 167 * 168 * The untimed DRM_*WAIT*_UNTIL macros return 169 * 170 * . -EINTR/-ERESTART if interrupted by a signal, or 171 * . zero if the condition evaluated 172 * 173 * The timed DRM_*TIMED_WAIT*_UNTIL macros return 174 * 175 * . -EINTR/-ERESTART if interrupted by a signal, 176 * . 0 if the condition was false after the timeout, 177 * . 1 if the condition was true just after the timeout, or 178 * . the number of ticks remaining if the condition was true before the 179 * timeout. 180 * 181 * Contrast DRM_SPIN_WAIT_ON which returns -EINTR/-ERESTART on signal, 182 * -EBUSY on timeout, and zero on success; and cv_*wait*, which return 183 * -EINTR/-ERESTART on signal, -EWOULDBLOCK on timeout, and zero on 184 * success. 185 * 186 * XXX In retrospect, giving the timed and untimed macros a different 187 * return convention from one another to match Linux may have been a 188 * bad idea. All of this inconsistent timeout return convention logic 189 * has been a consistent source of bugs. 190 */ 191 192 #define _DRM_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, CONDITION) do \ 193 { \ 194 KASSERT(mutex_is_locked((INTERLOCK))); \ 195 ASSERT_SLEEPABLE(); \ 196 KASSERT(!cold); \ 197 for (;;) { \ 198 if (CONDITION) { \ 199 (RET) = 0; \ 200 break; \ 201 } \ 202 /* XXX errno NetBSD->Linux */ \ 203 (RET) = -WAIT((Q), &(INTERLOCK)->mtx_lock); \ 204 if (RET) \ 205 break; \ 206 } \ 207 } while (0) 208 209 #define cv_wait_nointr(Q, I) (cv_wait((Q), (I)), 0) 210 211 #define DRM_WAIT_NOINTR_UNTIL(RET, Q, I, C) \ 212 _DRM_WAIT_UNTIL(RET, cv_wait_nointr, Q, I, C) 213 214 #define DRM_WAIT_UNTIL(RET, Q, I, C) \ 215 _DRM_WAIT_UNTIL(RET, cv_wait_sig, Q, I, C) 216 217 #define _DRM_TIMED_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, TICKS, CONDITION) do \ 218 { \ 219 unsigned _dtwu_ticks = (TICKS); \ 220 unsigned _dtwu_start, _dtwu_end; \ 221 \ 222 KASSERT(mutex_is_locked((INTERLOCK))); \ 223 ASSERT_SLEEPABLE(); \ 224 KASSERT(!cold); \ 225 \ 226 for (;;) { \ 227 if (CONDITION) { \ 228 (RET) = MAX(_dtwu_ticks, 1); \ 229 break; \ 230 } \ 231 if (_dtwu_ticks == 0) { \ 232 (RET) = 0; \ 233 break; \ 234 } \ 235 _dtwu_start = hardclock_ticks; \ 236 /* XXX errno NetBSD->Linux */ \ 237 (RET) = -WAIT((Q), &(INTERLOCK)->mtx_lock, \ 238 MIN(_dtwu_ticks, INT_MAX/2)); \ 239 _dtwu_end = hardclock_ticks; \ 240 if ((_dtwu_end - _dtwu_start) < _dtwu_ticks) \ 241 _dtwu_ticks -= _dtwu_end - _dtwu_start; \ 242 else \ 243 _dtwu_ticks = 0; \ 244 if (RET) { \ 245 if ((RET) == -EWOULDBLOCK) \ 246 (RET) = (CONDITION) ? 1 : 0; \ 247 break; \ 248 } \ 249 } \ 250 } while (0) 251 252 #define DRM_TIMED_WAIT_NOINTR_UNTIL(RET, Q, I, T, C) \ 253 _DRM_TIMED_WAIT_UNTIL(RET, cv_timedwait, Q, I, T, C) 254 255 #define DRM_TIMED_WAIT_UNTIL(RET, Q, I, T, C) \ 256 _DRM_TIMED_WAIT_UNTIL(RET, cv_timedwait_sig, Q, I, T, C) 257 258 /* 259 * XXX Can't assert sleepable here because we hold a spin lock. At 260 * least we can assert that we're not in (soft) interrupt context, and 261 * hope that nobody tries to use these with a sometimes quickly 262 * satisfied condition while holding a different spin lock. 263 */ 264 265 #define _DRM_SPIN_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, CONDITION) do \ 266 { \ 267 KASSERT(spin_is_locked((INTERLOCK))); \ 268 KASSERT(!cpu_intr_p()); \ 269 KASSERT(!cpu_softintr_p()); \ 270 KASSERT(!cold); \ 271 (RET) = 0; \ 272 while (!(CONDITION)) { \ 273 /* XXX errno NetBSD->Linux */ \ 274 (RET) = -WAIT((Q), &(INTERLOCK)->sl_lock); \ 275 if (RET) \ 276 break; \ 277 } \ 278 } while (0) 279 280 #define DRM_SPIN_WAIT_NOINTR_UNTIL(RET, Q, I, C) \ 281 _DRM_SPIN_WAIT_UNTIL(RET, cv_wait_nointr, Q, I, C) 282 283 #define DRM_SPIN_WAIT_UNTIL(RET, Q, I, C) \ 284 _DRM_SPIN_WAIT_UNTIL(RET, cv_wait_sig, Q, I, C) 285 286 #define _DRM_SPIN_TIMED_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, TICKS, CONDITION) \ 287 do \ 288 { \ 289 unsigned _dstwu_ticks = (TICKS); \ 290 unsigned _dstwu_start, _dstwu_end; \ 291 \ 292 KASSERT(spin_is_locked((INTERLOCK))); \ 293 KASSERT(!cpu_intr_p()); \ 294 KASSERT(!cpu_softintr_p()); \ 295 KASSERT(!cold); \ 296 \ 297 for (;;) { \ 298 if (CONDITION) { \ 299 (RET) = MAX(_dstwu_ticks, 1); \ 300 break; \ 301 } \ 302 if (_dstwu_ticks == 0) { \ 303 (RET) = 0; \ 304 break; \ 305 } \ 306 _dstwu_start = hardclock_ticks; \ 307 /* XXX errno NetBSD->Linux */ \ 308 (RET) = -WAIT((Q), &(INTERLOCK)->sl_lock, \ 309 MIN(_dstwu_ticks, INT_MAX/2)); \ 310 _dstwu_end = hardclock_ticks; \ 311 if ((_dstwu_end - _dstwu_start) < _dstwu_ticks) \ 312 _dstwu_ticks -= _dstwu_end - _dstwu_start; \ 313 else \ 314 _dstwu_ticks = 0; \ 315 if (RET) { \ 316 if ((RET) == -EWOULDBLOCK) \ 317 (RET) = (CONDITION) ? 1 : 0; \ 318 break; \ 319 } \ 320 } \ 321 } while (0) 322 323 #define DRM_SPIN_TIMED_WAIT_NOINTR_UNTIL(RET, Q, I, T, C) \ 324 _DRM_SPIN_TIMED_WAIT_UNTIL(RET, cv_timedwait, Q, I, T, C) 325 326 #define DRM_SPIN_TIMED_WAIT_UNTIL(RET, Q, I, T, C) \ 327 _DRM_SPIN_TIMED_WAIT_UNTIL(RET, cv_timedwait_sig, Q, I, T, C) 328 329 #endif /* _DRM_DRM_WAIT_NETBSD_H_ */ 330
Indexes created Tue Sep 30 20:09:53 GMT 2025