drm_wait_netbsd.h revision 1.14.18.1
1 /* $NetBSD: drm_wait_netbsd.h,v 1.14.18.1 2019/06/10 22:08:31 christos 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 #include <sys/cpu.h> /* cpu_intr_p */ 38 #include <sys/kernel.h> 39 #include <sys/mutex.h> 40 #include <sys/systm.h> 41 42 #include <linux/mutex.h> 43 #include <linux/spinlock.h> 44 45 typedef kcondvar_t drm_waitqueue_t; 46 47 #define DRM_HZ hz /* XXX Hurk... */ 48 49 #define DRM_UDELAY DELAY 50 51 static inline void 52 DRM_INIT_WAITQUEUE(drm_waitqueue_t *q, const char *name) 53 { 54 cv_init(q, name); 55 } 56 57 static inline void 58 DRM_DESTROY_WAITQUEUE(drm_waitqueue_t *q) 59 { 60 cv_destroy(q); 61 } 62 63 static inline bool 64 DRM_WAITERS_P(drm_waitqueue_t *q, struct mutex *interlock) 65 { 66 KASSERT(mutex_is_locked(interlock)); 67 return cv_has_waiters(q); 68 } 69 70 static inline void 71 DRM_WAKEUP_ONE(drm_waitqueue_t *q, struct mutex *interlock) 72 { 73 KASSERT(mutex_is_locked(interlock)); 74 cv_signal(q); 75 } 76 77 static inline void 78 DRM_WAKEUP_ALL(drm_waitqueue_t *q, struct mutex *interlock) 79 { 80 KASSERT(mutex_is_locked(interlock)); 81 cv_broadcast(q); 82 } 83 84 static inline bool 85 DRM_SPIN_WAITERS_P(drm_waitqueue_t *q, spinlock_t *interlock) 86 { 87 KASSERT(spin_is_locked(interlock)); 88 return cv_has_waiters(q); 89 } 90 91 static inline void 92 DRM_SPIN_WAKEUP_ONE(drm_waitqueue_t *q, spinlock_t *interlock) 93 { 94 KASSERT(spin_is_locked(interlock)); 95 cv_signal(q); 96 } 97 98 static inline void 99 DRM_SPIN_WAKEUP_ALL(drm_waitqueue_t *q, spinlock_t *interlock) 100 { 101 KASSERT(spin_is_locked(interlock)); 102 cv_broadcast(q); 103 } 104 105 /* 106 * DRM_SPIN_WAIT_ON is a replacement for the legacy DRM_WAIT_ON 107 * portability macro. It requires a spin interlock, which may require 108 * changes to the surrounding code so that the waits actually are 109 * interlocked by a spin lock. It also polls the condition at every 110 * tick, which masks missing wakeups. Since DRM_WAIT_ON is going away, 111 * in favour of Linux's native wait_event* API, waits in new code 112 * should be written to use the DRM_*WAIT*_UNTIL macros below. 113 * 114 * Like the legacy DRM_WAIT_ON, DRM_SPIN_WAIT_ON returns 115 * 116 * . -EBUSY if timed out (yes, -EBUSY, not -ETIMEDOUT or -EWOULDBLOCK), 117 * . -EINTR/-ERESTARTSYS if interrupted by a signal, or 118 * . 0 if the condition was true before or just after the timeout. 119 * 120 * Note that cv_timedwait* return -EWOULDBLOCK, not -EBUSY, on timeout. 121 * 122 * Note that ERESTARTSYS is actually ELAST+1 and only used in Linux 123 * code and must be converted for use in NetBSD code (user or kernel.) 124 */ 125 126 #define DRM_SPIN_WAIT_ON(RET, Q, INTERLOCK, TICKS, CONDITION) do \ 127 { \ 128 unsigned _dswo_ticks = (TICKS); \ 129 unsigned _dswo_start, _dswo_end; \ 130 \ 131 KASSERT(spin_is_locked((INTERLOCK))); \ 132 KASSERT(!cpu_intr_p()); \ 133 KASSERT(!cpu_softintr_p()); \ 134 KASSERT(!cold); \ 135 \ 136 for (;;) { \ 137 if (CONDITION) { \ 138 (RET) = 0; \ 139 break; \ 140 } \ 141 if (_dswo_ticks == 0) { \ 142 (RET) = -EBUSY; /* Match Linux... */ \ 143 break; \ 144 } \ 145 _dswo_start = hardclock_ticks; \ 146 /* XXX errno NetBSD->Linux */ \ 147 (RET) = -cv_timedwait_sig((Q), &(INTERLOCK)->sl_lock, 1); \ 148 _dswo_end = hardclock_ticks; \ 149 if (_dswo_end - _dswo_start < _dswo_ticks) \ 150 _dswo_ticks -= _dswo_end - _dswo_start; \ 151 else \ 152 _dswo_ticks = 0; \ 153 if (RET) { \ 154 if ((RET) == -ERESTART) \ 155 (RET) = -ERESTARTSYS; \ 156 if ((RET) == -EWOULDBLOCK) \ 157 /* Waited only one tick. */ \ 158 continue; \ 159 break; \ 160 } \ 161 } \ 162 } while (0) 163 164 /* 165 * The DRM_*WAIT*_UNTIL macros are replacements for the Linux 166 * wait_event* macros. Like DRM_SPIN_WAIT_ON, they add an interlock, 167 * and so may require some changes to the surrounding code. They have 168 * a different return value convention from DRM_SPIN_WAIT_ON and a 169 * different return value convention from cv_*wait*. 170 * 171 * The untimed DRM_*WAIT*_UNTIL macros return 172 * 173 * . -EINTR/-ERESTARTSYS if interrupted by a signal, or 174 * . zero if the condition evaluated 175 * 176 * The timed DRM_*TIMED_WAIT*_UNTIL macros return 177 * 178 * . -EINTR/-ERESTARTSYS if interrupted by a signal, 179 * . 0 if the condition was false after the timeout, 180 * . 1 if the condition was true just after the timeout, or 181 * . the number of ticks remaining if the condition was true before the 182 * timeout. 183 * 184 * Contrast DRM_SPIN_WAIT_ON which returns -EINTR/-ERESTARTSYS on signal, 185 * -EBUSY on timeout, and zero on success; and cv_*wait*, which return 186 * -EINTR/-ERESTARTSYS on signal, -EWOULDBLOCK on timeout, and zero on 187 * success. 188 * 189 * XXX In retrospect, giving the timed and untimed macros a different 190 * return convention from one another to match Linux may have been a 191 * bad idea. All of this inconsistent timeout return convention logic 192 * has been a consistent source of bugs. 193 * 194 * Note that ERESTARTSYS is actually ELAST+1 and only used in Linux 195 * code and must be converted for use in NetBSD code (user or kernel.) 196 */ 197 198 #define _DRM_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, CONDITION) do \ 199 { \ 200 KASSERT(mutex_is_locked((INTERLOCK))); \ 201 ASSERT_SLEEPABLE(); \ 202 KASSERT(!cold); \ 203 for (;;) { \ 204 if (CONDITION) { \ 205 (RET) = 0; \ 206 break; \ 207 } \ 208 /* XXX errno NetBSD->Linux */ \ 209 (RET) = -WAIT((Q), &(INTERLOCK)->mtx_lock); \ 210 if (RET) { \ 211 if ((RET) == -ERESTART) \ 212 (RET) = -ERESTARTSYS; \ 213 break; \ 214 } \ 215 } \ 216 } while (0) 217 218 #define cv_wait_nointr(Q, I) (cv_wait((Q), (I)), 0) 219 220 #define DRM_WAIT_NOINTR_UNTIL(RET, Q, I, C) \ 221 _DRM_WAIT_UNTIL(RET, cv_wait_nointr, Q, I, C) 222 223 #define DRM_WAIT_UNTIL(RET, Q, I, C) \ 224 _DRM_WAIT_UNTIL(RET, cv_wait_sig, Q, I, C) 225 226 #define _DRM_TIMED_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, TICKS, CONDITION) do \ 227 { \ 228 unsigned _dtwu_ticks = (TICKS); \ 229 unsigned _dtwu_start, _dtwu_end; \ 230 \ 231 KASSERT(mutex_is_locked((INTERLOCK))); \ 232 ASSERT_SLEEPABLE(); \ 233 KASSERT(!cold); \ 234 \ 235 for (;;) { \ 236 if (CONDITION) { \ 237 (RET) = MAX(_dtwu_ticks, 1); \ 238 break; \ 239 } \ 240 if (_dtwu_ticks == 0) { \ 241 (RET) = 0; \ 242 break; \ 243 } \ 244 _dtwu_start = hardclock_ticks; \ 245 /* XXX errno NetBSD->Linux */ \ 246 (RET) = -WAIT((Q), &(INTERLOCK)->mtx_lock, \ 247 MIN(_dtwu_ticks, INT_MAX/2)); \ 248 _dtwu_end = hardclock_ticks; \ 249 if ((_dtwu_end - _dtwu_start) < _dtwu_ticks) \ 250 _dtwu_ticks -= _dtwu_end - _dtwu_start; \ 251 else \ 252 _dtwu_ticks = 0; \ 253 if (RET) { \ 254 if ((RET) == -ERESTART) \ 255 (RET) = -ERESTARTSYS; \ 256 if ((RET) == -EWOULDBLOCK) \ 257 (RET) = (CONDITION) ? 1 : 0; \ 258 break; \ 259 } \ 260 } \ 261 } while (0) 262 263 #define DRM_TIMED_WAIT_NOINTR_UNTIL(RET, Q, I, T, C) \ 264 _DRM_TIMED_WAIT_UNTIL(RET, cv_timedwait, Q, I, T, C) 265 266 #define DRM_TIMED_WAIT_UNTIL(RET, Q, I, T, C) \ 267 _DRM_TIMED_WAIT_UNTIL(RET, cv_timedwait_sig, Q, I, T, C) 268 269 /* 270 * XXX Can't assert sleepable here because we hold a spin lock. At 271 * least we can assert that we're not in (soft) interrupt context, and 272 * hope that nobody tries to use these with a sometimes quickly 273 * satisfied condition while holding a different spin lock. 274 */ 275 276 #define _DRM_SPIN_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, CONDITION) do \ 277 { \ 278 KASSERT(spin_is_locked((INTERLOCK))); \ 279 KASSERT(!cpu_intr_p()); \ 280 KASSERT(!cpu_softintr_p()); \ 281 KASSERT(!cold); \ 282 (RET) = 0; \ 283 while (!(CONDITION)) { \ 284 /* XXX errno NetBSD->Linux */ \ 285 (RET) = -WAIT((Q), &(INTERLOCK)->sl_lock); \ 286 if ((RET) == -ERESTART) \ 287 (RET) = -ERESTARTSYS; \ 288 if (RET) \ 289 break; \ 290 } \ 291 } while (0) 292 293 #define DRM_SPIN_WAIT_NOINTR_UNTIL(RET, Q, I, C) \ 294 _DRM_SPIN_WAIT_UNTIL(RET, cv_wait_nointr, Q, I, C) 295 296 #define DRM_SPIN_WAIT_UNTIL(RET, Q, I, C) \ 297 _DRM_SPIN_WAIT_UNTIL(RET, cv_wait_sig, Q, I, C) 298 299 #define _DRM_SPIN_TIMED_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, TICKS, CONDITION) \ 300 do \ 301 { \ 302 unsigned _dstwu_ticks = (TICKS); \ 303 unsigned _dstwu_start, _dstwu_end; \ 304 \ 305 KASSERT(spin_is_locked((INTERLOCK))); \ 306 KASSERT(!cpu_intr_p()); \ 307 KASSERT(!cpu_softintr_p()); \ 308 KASSERT(!cold); \ 309 \ 310 for (;;) { \ 311 if (CONDITION) { \ 312 (RET) = MAX(_dstwu_ticks, 1); \ 313 break; \ 314 } \ 315 if (_dstwu_ticks == 0) { \ 316 (RET) = 0; \ 317 break; \ 318 } \ 319 _dstwu_start = hardclock_ticks; \ 320 /* XXX errno NetBSD->Linux */ \ 321 (RET) = -WAIT((Q), &(INTERLOCK)->sl_lock, \ 322 MIN(_dstwu_ticks, INT_MAX/2)); \ 323 _dstwu_end = hardclock_ticks; \ 324 if ((_dstwu_end - _dstwu_start) < _dstwu_ticks) \ 325 _dstwu_ticks -= _dstwu_end - _dstwu_start; \ 326 else \ 327 _dstwu_ticks = 0; \ 328 if (RET) { \ 329 if ((RET) == -ERESTART) \ 330 (RET) = -ERESTARTSYS; \ 331 if ((RET) == -EWOULDBLOCK) \ 332 (RET) = (CONDITION) ? 1 : 0; \ 333 break; \ 334 } \ 335 } \ 336 } while (0) 337 338 #define DRM_SPIN_TIMED_WAIT_NOINTR_UNTIL(RET, Q, I, T, C) \ 339 _DRM_SPIN_TIMED_WAIT_UNTIL(RET, cv_timedwait, Q, I, T, C) 340 341 #define DRM_SPIN_TIMED_WAIT_UNTIL(RET, Q, I, T, C) \ 342 _DRM_SPIN_TIMED_WAIT_UNTIL(RET, cv_timedwait_sig, Q, I, T, C) 343 344 #endif /* _DRM_DRM_WAIT_NETBSD_H_ */ 345
Indexes created Tue Sep 30 20:09:53 GMT 2025