drm_wait_netbsd.h revision 1.14.10.1
1 /* $NetBSD: drm_wait_netbsd.h,v 1.14.10.1 2019/04/23 10:16:52 martin 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/errno.h> 43 #include <linux/mutex.h> 44 #include <linux/spinlock.h> 45 46 typedef kcondvar_t drm_waitqueue_t; 47 48 #define DRM_HZ hz /* XXX Hurk... */ 49 50 #define DRM_UDELAY DELAY 51 52 static inline void 53 DRM_INIT_WAITQUEUE(drm_waitqueue_t *q, const char *name) 54 { 55 cv_init(q, name); 56 } 57 58 static inline void 59 DRM_DESTROY_WAITQUEUE(drm_waitqueue_t *q) 60 { 61 cv_destroy(q); 62 } 63 64 static inline bool 65 DRM_WAITERS_P(drm_waitqueue_t *q, struct mutex *interlock) 66 { 67 KASSERT(mutex_is_locked(interlock)); 68 return cv_has_waiters(q); 69 } 70 71 static inline void 72 DRM_WAKEUP_ONE(drm_waitqueue_t *q, struct mutex *interlock) 73 { 74 KASSERT(mutex_is_locked(interlock)); 75 cv_signal(q); 76 } 77 78 static inline void 79 DRM_WAKEUP_ALL(drm_waitqueue_t *q, struct mutex *interlock) 80 { 81 KASSERT(mutex_is_locked(interlock)); 82 cv_broadcast(q); 83 } 84 85 static inline bool 86 DRM_SPIN_WAITERS_P(drm_waitqueue_t *q, spinlock_t *interlock) 87 { 88 KASSERT(spin_is_locked(interlock)); 89 return cv_has_waiters(q); 90 } 91 92 static inline void 93 DRM_SPIN_WAKEUP_ONE(drm_waitqueue_t *q, spinlock_t *interlock) 94 { 95 KASSERT(spin_is_locked(interlock)); 96 cv_signal(q); 97 } 98 99 static inline void 100 DRM_SPIN_WAKEUP_ALL(drm_waitqueue_t *q, spinlock_t *interlock) 101 { 102 KASSERT(spin_is_locked(interlock)); 103 cv_broadcast(q); 104 } 105 106 /* 107 * DRM_SPIN_WAIT_ON is a replacement for the legacy DRM_WAIT_ON 108 * portability macro. It requires a spin interlock, which may require 109 * changes to the surrounding code so that the waits actually are 110 * interlocked by a spin lock. It also polls the condition at every 111 * tick, which masks missing wakeups. Since DRM_WAIT_ON is going away, 112 * in favour of Linux's native wait_event* API, waits in new code 113 * should be written to use the DRM_*WAIT*_UNTIL macros below. 114 * 115 * Like the legacy DRM_WAIT_ON, DRM_SPIN_WAIT_ON returns 116 * 117 * . -EBUSY if timed out (yes, -EBUSY, not -ETIMEDOUT or -EWOULDBLOCK), 118 * . -EINTR/-ERESTARTSYS if interrupted by a signal, or 119 * . 0 if the condition was true before or just after the timeout. 120 * 121 * Note that cv_timedwait* return -EWOULDBLOCK, not -EBUSY, on timeout. 122 * 123 * Note that ERESTARTSYS is actually ELAST+1 and only used in Linux 124 * code and must be converted for use in NetBSD code (user or kernel.) 125 */ 126 127 #define DRM_SPIN_WAIT_ON(RET, Q, INTERLOCK, TICKS, CONDITION) do \ 128 { \ 129 unsigned _dswo_ticks = (TICKS); \ 130 unsigned _dswo_start, _dswo_end; \ 131 \ 132 KASSERT(spin_is_locked((INTERLOCK))); \ 133 KASSERT(!cpu_intr_p()); \ 134 KASSERT(!cpu_softintr_p()); \ 135 KASSERT(!cold); \ 136 \ 137 for (;;) { \ 138 if (CONDITION) { \ 139 (RET) = 0; \ 140 break; \ 141 } \ 142 if (_dswo_ticks == 0) { \ 143 (RET) = -EBUSY; /* Match Linux... */ \ 144 break; \ 145 } \ 146 _dswo_start = hardclock_ticks; \ 147 /* XXX errno NetBSD->Linux */ \ 148 (RET) = -cv_timedwait_sig((Q), &(INTERLOCK)->sl_lock, 1); \ 149 _dswo_end = hardclock_ticks; \ 150 if (_dswo_end - _dswo_start < _dswo_ticks) \ 151 _dswo_ticks -= _dswo_end - _dswo_start; \ 152 else \ 153 _dswo_ticks = 0; \ 154 if (RET) { \ 155 if ((RET) == -ERESTART) \ 156 (RET) = -ERESTARTSYS; \ 157 if ((RET) == -EWOULDBLOCK) \ 158 /* Waited only one tick. */ \ 159 continue; \ 160 break; \ 161 } \ 162 } \ 163 } while (0) 164 165 /* 166 * The DRM_*WAIT*_UNTIL macros are replacements for the Linux 167 * wait_event* macros. Like DRM_SPIN_WAIT_ON, they add an interlock, 168 * and so may require some changes to the surrounding code. They have 169 * a different return value convention from DRM_SPIN_WAIT_ON and a 170 * different return value convention from cv_*wait*. 171 * 172 * The untimed DRM_*WAIT*_UNTIL macros return 173 * 174 * . -EINTR/-ERESTARTSYS if interrupted by a signal, or 175 * . zero if the condition evaluated 176 * 177 * The timed DRM_*TIMED_WAIT*_UNTIL macros return 178 * 179 * . -EINTR/-ERESTARTSYS if interrupted by a signal, 180 * . 0 if the condition was false after the timeout, 181 * . 1 if the condition was true just after the timeout, or 182 * . the number of ticks remaining if the condition was true before the 183 * timeout. 184 * 185 * Contrast DRM_SPIN_WAIT_ON which returns -EINTR/-ERESTARTSYS on signal, 186 * -EBUSY on timeout, and zero on success; and cv_*wait*, which return 187 * -EINTR/-ERESTARTSYS on signal, -EWOULDBLOCK on timeout, and zero on 188 * success. 189 * 190 * XXX In retrospect, giving the timed and untimed macros a different 191 * return convention from one another to match Linux may have been a 192 * bad idea. All of this inconsistent timeout return convention logic 193 * has been a consistent source of bugs. 194 * 195 * Note that ERESTARTSYS is actually ELAST+1 and only used in Linux 196 * code and must be converted for use in NetBSD code (user or kernel.) 197 */ 198 199 #define _DRM_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, CONDITION) do \ 200 { \ 201 KASSERT(mutex_is_locked((INTERLOCK))); \ 202 ASSERT_SLEEPABLE(); \ 203 KASSERT(!cold); \ 204 for (;;) { \ 205 if (CONDITION) { \ 206 (RET) = 0; \ 207 break; \ 208 } \ 209 /* XXX errno NetBSD->Linux */ \ 210 (RET) = -WAIT((Q), &(INTERLOCK)->mtx_lock); \ 211 if (RET) { \ 212 if ((RET) == -ERESTART) \ 213 (RET) = -ERESTARTSYS; \ 214 break; \ 215 } \ 216 } \ 217 } while (0) 218 219 #define cv_wait_nointr(Q, I) (cv_wait((Q), (I)), 0) 220 221 #define DRM_WAIT_NOINTR_UNTIL(RET, Q, I, C) \ 222 _DRM_WAIT_UNTIL(RET, cv_wait_nointr, Q, I, C) 223 224 #define DRM_WAIT_UNTIL(RET, Q, I, C) \ 225 _DRM_WAIT_UNTIL(RET, cv_wait_sig, Q, I, C) 226 227 #define _DRM_TIMED_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, TICKS, CONDITION) do \ 228 { \ 229 unsigned _dtwu_ticks = (TICKS); \ 230 unsigned _dtwu_start, _dtwu_end; \ 231 \ 232 KASSERT(mutex_is_locked((INTERLOCK))); \ 233 ASSERT_SLEEPABLE(); \ 234 KASSERT(!cold); \ 235 \ 236 for (;;) { \ 237 if (CONDITION) { \ 238 (RET) = MAX(_dtwu_ticks, 1); \ 239 break; \ 240 } \ 241 if (_dtwu_ticks == 0) { \ 242 (RET) = 0; \ 243 break; \ 244 } \ 245 _dtwu_start = hardclock_ticks; \ 246 /* XXX errno NetBSD->Linux */ \ 247 (RET) = -WAIT((Q), &(INTERLOCK)->mtx_lock, \ 248 MIN(_dtwu_ticks, INT_MAX/2)); \ 249 _dtwu_end = hardclock_ticks; \ 250 if ((_dtwu_end - _dtwu_start) < _dtwu_ticks) \ 251 _dtwu_ticks -= _dtwu_end - _dtwu_start; \ 252 else \ 253 _dtwu_ticks = 0; \ 254 if (RET) { \ 255 if ((RET) == -ERESTART) \ 256 (RET) = -ERESTARTSYS; \ 257 if ((RET) == -EWOULDBLOCK) \ 258 (RET) = (CONDITION) ? 1 : 0; \ 259 break; \ 260 } \ 261 } \ 262 } while (0) 263 264 #define DRM_TIMED_WAIT_NOINTR_UNTIL(RET, Q, I, T, C) \ 265 _DRM_TIMED_WAIT_UNTIL(RET, cv_timedwait, Q, I, T, C) 266 267 #define DRM_TIMED_WAIT_UNTIL(RET, Q, I, T, C) \ 268 _DRM_TIMED_WAIT_UNTIL(RET, cv_timedwait_sig, Q, I, T, C) 269 270 /* 271 * XXX Can't assert sleepable here because we hold a spin lock. At 272 * least we can assert that we're not in (soft) interrupt context, and 273 * hope that nobody tries to use these with a sometimes quickly 274 * satisfied condition while holding a different spin lock. 275 */ 276 277 #define _DRM_SPIN_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, CONDITION) do \ 278 { \ 279 KASSERT(spin_is_locked((INTERLOCK))); \ 280 KASSERT(!cpu_intr_p()); \ 281 KASSERT(!cpu_softintr_p()); \ 282 KASSERT(!cold); \ 283 (RET) = 0; \ 284 while (!(CONDITION)) { \ 285 /* XXX errno NetBSD->Linux */ \ 286 (RET) = -WAIT((Q), &(INTERLOCK)->sl_lock); \ 287 if ((RET) == -ERESTART) \ 288 (RET) = -ERESTARTSYS; \ 289 if (RET) \ 290 break; \ 291 } \ 292 } while (0) 293 294 #define DRM_SPIN_WAIT_NOINTR_UNTIL(RET, Q, I, C) \ 295 _DRM_SPIN_WAIT_UNTIL(RET, cv_wait_nointr, Q, I, C) 296 297 #define DRM_SPIN_WAIT_UNTIL(RET, Q, I, C) \ 298 _DRM_SPIN_WAIT_UNTIL(RET, cv_wait_sig, Q, I, C) 299 300 #define _DRM_SPIN_TIMED_WAIT_UNTIL(RET, WAIT, Q, INTERLOCK, TICKS, CONDITION) \ 301 do \ 302 { \ 303 unsigned _dstwu_ticks = (TICKS); \ 304 unsigned _dstwu_start, _dstwu_end; \ 305 \ 306 KASSERT(spin_is_locked((INTERLOCK))); \ 307 KASSERT(!cpu_intr_p()); \ 308 KASSERT(!cpu_softintr_p()); \ 309 KASSERT(!cold); \ 310 \ 311 for (;;) { \ 312 if (CONDITION) { \ 313 (RET) = MAX(_dstwu_ticks, 1); \ 314 break; \ 315 } \ 316 if (_dstwu_ticks == 0) { \ 317 (RET) = 0; \ 318 break; \ 319 } \ 320 _dstwu_start = hardclock_ticks; \ 321 /* XXX errno NetBSD->Linux */ \ 322 (RET) = -WAIT((Q), &(INTERLOCK)->sl_lock, \ 323 MIN(_dstwu_ticks, INT_MAX/2)); \ 324 _dstwu_end = hardclock_ticks; \ 325 if ((_dstwu_end - _dstwu_start) < _dstwu_ticks) \ 326 _dstwu_ticks -= _dstwu_end - _dstwu_start; \ 327 else \ 328 _dstwu_ticks = 0; \ 329 if (RET) { \ 330 if ((RET) == -ERESTART) \ 331 (RET) = -ERESTARTSYS; \ 332 if ((RET) == -EWOULDBLOCK) \ 333 (RET) = (CONDITION) ? 1 : 0; \ 334 break; \ 335 } \ 336 } \ 337 } while (0) 338 339 #define DRM_SPIN_TIMED_WAIT_NOINTR_UNTIL(RET, Q, I, T, C) \ 340 _DRM_SPIN_TIMED_WAIT_UNTIL(RET, cv_timedwait, Q, I, T, C) 341 342 #define DRM_SPIN_TIMED_WAIT_UNTIL(RET, Q, I, T, C) \ 343 _DRM_SPIN_TIMED_WAIT_UNTIL(RET, cv_timedwait_sig, Q, I, T, C) 344 345 #endif /* _DRM_DRM_WAIT_NETBSD_H_ */ 346
Indexes created Tue Sep 30 20:09:53 GMT 2025