1 /* 2 * Copyright © 2016 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 */ 24 25 #ifndef __I915_UTILS_H 26 #define __I915_UTILS_H 27 28 #include <linux/list.h> 29 #include <linux/overflow.h> 30 #include <linux/sched.h> 31 #include <linux/types.h> 32 #include <linux/workqueue.h> 33 34 struct drm_i915_private; 35 struct timer_list; 36 37 #define FDO_BUG_URL "https://gitlab.freedesktop.org/drm/intel/-/wikis/How-to-file-i915-bugs" 38 39 #undef WARN_ON 40 /* Many gcc seem to no see through this and fall over :( */ 41 #if 0 42 #define WARN_ON(x) ({ \ 43 bool __i915_warn_cond = (x); \ 44 if (__builtin_constant_p(__i915_warn_cond)) \ 45 BUILD_BUG_ON(__i915_warn_cond); \ 46 WARN(__i915_warn_cond, "WARN_ON(" #x ")"); }) 47 #else 48 #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")") 49 #endif 50 51 #undef WARN_ON_ONCE 52 #define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")") 53 54 #define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \ 55 __stringify(x), (long)(x)) 56 57 void __printf(3, 4) 58 __i915_printk(struct drm_i915_private *dev_priv, const char *level, 59 const char *fmt, ...); 60 61 #define i915_report_error(dev_priv, fmt, ...) \ 62 __i915_printk(dev_priv, KERN_ERR, fmt, ##__VA_ARGS__) 63 64 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG) 65 66 int __i915_inject_probe_error(struct drm_i915_private *i915, int err, 67 const char *func, int line); 68 #define i915_inject_probe_error(_i915, _err) \ 69 __i915_inject_probe_error((_i915), (_err), __func__, __LINE__) 70 bool i915_error_injected(void); 71 72 #else 73 74 #define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; }) 75 #define i915_error_injected() false 76 77 #endif 78 79 #define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV) 80 81 #define i915_probe_error(i915, fmt, ...) \ 82 __i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \ 83 fmt, ##__VA_ARGS__) 84 85 #if defined(GCC_VERSION) && GCC_VERSION >= 70000 86 #define add_overflows_t(T, A, B) \ 87 __builtin_add_overflow_p((A), (B), (T)0) 88 #else 89 #define add_overflows_t(T, A, B) ({ \ 90 typeof(A) a = (A); \ 91 typeof(B) b = (B); \ 92 (T)(a + b) < a; \ 93 }) 94 #endif 95 96 #define add_overflows(A, B) \ 97 add_overflows_t(typeof((A) + (B)), (A), (B)) 98 99 #define range_overflows(start, size, max) ({ \ 100 typeof(start) start__ = (start); \ 101 typeof(size) size__ = (size); \ 102 typeof(max) max__ = (max); \ 103 (void)(&start__ == &size__); \ 104 (void)(&start__ == &max__); \ 105 start__ >= max__ || size__ > max__ - start__; \ 106 }) 107 108 #define range_overflows_t(type, start, size, max) \ 109 range_overflows((type)(start), (type)(size), (type)(max)) 110 111 #define range_overflows_end(start, size, max) ({ \ 112 typeof(start) start__ = (start); \ 113 typeof(size) size__ = (size); \ 114 typeof(max) max__ = (max); \ 115 (void)(&start__ == &size__); \ 116 (void)(&start__ == &max__); \ 117 start__ > max__ || size__ > max__ - start__; \ 118 }) 119 120 #define range_overflows_end_t(type, start, size, max) \ 121 range_overflows_end((type)(start), (type)(size), (type)(max)) 122 123 /* Note we don't consider signbits :| */ 124 #define overflows_type(x, T) \ 125 (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T)) 126 127 static inline bool 128 __check_struct_size(size_t base, size_t arr, size_t count, size_t *size) 129 { 130 size_t sz; 131 132 if (check_mul_overflow(count, arr, &sz)) 133 return false; 134 135 if (check_add_overflow(sz, base, &sz)) 136 return false; 137 138 *size = sz; 139 return true; 140 } 141 142 /** 143 * check_struct_size() - Calculate size of structure with trailing array. 144 * @p: Pointer to the structure. 145 * @member: Name of the array member. 146 * @n: Number of elements in the array. 147 * @sz: Total size of structure and array 148 * 149 * Calculates size of memory needed for structure @p followed by an 150 * array of @n @member elements, like struct_size() but reports 151 * whether it overflowed, and the resultant size in @sz 152 * 153 * Return: false if the calculation overflowed. 154 */ 155 #define check_struct_size(p, member, n, sz) \ 156 likely(__check_struct_size(sizeof(*(p)), \ 157 sizeof(*(p)->member) + __must_be_array((p)->member), \ 158 n, sz)) 159 160 #define ptr_mask_bits(ptr, n) ({ \ 161 unsigned long __v = (unsigned long)(ptr); \ 162 (typeof(ptr))(__v & -BIT(n)); \ 163 }) 164 165 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1)) 166 167 #define ptr_unpack_bits(ptr, bits, n) ({ \ 168 unsigned long __v = (unsigned long)(ptr); \ 169 *(bits) = __v & (BIT(n) - 1); \ 170 (typeof(ptr))(__v & -BIT(n)); \ 171 }) 172 173 #define ptr_pack_bits(ptr, bits, n) ({ \ 174 unsigned long __bits = (bits); \ 175 GEM_BUG_ON(__bits & -BIT(n)); \ 176 ((typeof(ptr))((unsigned long)(ptr) | __bits)); \ 177 }) 178 179 #define ptr_dec(ptr) ({ \ 180 unsigned long __v = (unsigned long)(ptr); \ 181 (typeof(ptr))(__v - 1); \ 182 }) 183 184 #define ptr_inc(ptr) ({ \ 185 unsigned long __v = (unsigned long)(ptr); \ 186 (typeof(ptr))(__v + 1); \ 187 }) 188 189 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT) 190 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT) 191 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT) 192 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT) 193 194 #define struct_member(T, member) (((T *)0)->member) 195 196 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member) 197 198 #define fetch_and_zero(ptr) ({ \ 199 typeof(*ptr) __T = *(ptr); \ 200 *(ptr) = (typeof(*ptr))0; \ 201 __T; \ 202 }) 203 204 /* 205 * container_of_user: Extract the superclass from a pointer to a member. 206 * 207 * Exactly like container_of() with the exception that it plays nicely 208 * with sparse for __user @ptr. 209 */ 210 #define container_of_user(ptr, type, member) ({ \ 211 void __user *__mptr = (void __user *)(ptr); \ 212 BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \ 213 !__same_type(*(ptr), void), \ 214 "pointer type mismatch in container_of()"); \ 215 ((type __user *)(__mptr - offsetof(type, member))); }) 216 217 /* 218 * check_user_mbz: Check that a user value exists and is zero 219 * 220 * Frequently in our uABI we reserve space for future extensions, and 221 * two ensure that userspace is prepared we enforce that space must 222 * be zero. (Then any future extension can safely assume a default value 223 * of 0.) 224 * 225 * check_user_mbz() combines checking that the user pointer is accessible 226 * and that the contained value is zero. 227 * 228 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success. 229 */ 230 #define check_user_mbz(U) ({ \ 231 typeof(*(U)) mbz__; \ 232 get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0; \ 233 }) 234 235 static inline u64 ptr_to_u64(const void *ptr) 236 { 237 return (uintptr_t)ptr; 238 } 239 240 #define u64_to_ptr(T, x) ({ \ 241 typecheck(u64, x); \ 242 (T *)(uintptr_t)(x); \ 243 }) 244 245 #define __mask_next_bit(mask) ({ \ 246 int __idx = ffs(mask) - 1; \ 247 mask &= ~BIT(__idx); \ 248 __idx; \ 249 }) 250 251 static inline bool is_power_of_2_u64(u64 n) 252 { 253 return (n != 0 && ((n & (n - 1)) == 0)); 254 } 255 256 static inline void __list_del_many(struct list_head *head, 257 struct list_head *first) 258 { 259 first->prev = head; 260 WRITE_ONCE(head->next, first); 261 } 262 263 static inline int list_is_last_rcu(const struct list_head *list, 264 const struct list_head *head) 265 { 266 return READ_ONCE(list->next) == head; 267 } 268 269 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m) 270 { 271 unsigned long j = msecs_to_jiffies(m); 272 273 return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1); 274 } 275 276 /* 277 * If you need to wait X milliseconds between events A and B, but event B 278 * doesn't happen exactly after event A, you record the timestamp (jiffies) of 279 * when event A happened, then just before event B you call this function and 280 * pass the timestamp as the first argument, and X as the second argument. 281 */ 282 static inline void 283 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms) 284 { 285 unsigned long target_jiffies, tmp_jiffies, remaining_jiffies; 286 287 /* 288 * Don't re-read the value of "jiffies" every time since it may change 289 * behind our back and break the math. 290 */ 291 tmp_jiffies = jiffies; 292 target_jiffies = timestamp_jiffies + 293 msecs_to_jiffies_timeout(to_wait_ms); 294 295 if (time_after(target_jiffies, tmp_jiffies)) { 296 remaining_jiffies = target_jiffies - tmp_jiffies; 297 while (remaining_jiffies) 298 remaining_jiffies = 299 schedule_timeout_uninterruptible(remaining_jiffies); 300 } 301 } 302 303 /** 304 * __wait_for - magic wait macro 305 * 306 * Macro to help avoid open coding check/wait/timeout patterns. Note that it's 307 * important that we check the condition again after having timed out, since the 308 * timeout could be due to preemption or similar and we've never had a chance to 309 * check the condition before the timeout. 310 */ 311 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \ 312 const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \ 313 long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \ 314 int ret__; \ 315 might_sleep(); \ 316 for (;;) { \ 317 const bool expired__ = ktime_after(ktime_get_raw(), end__); \ 318 OP; \ 319 /* Guarantee COND check prior to timeout */ \ 320 barrier(); \ 321 if (COND) { \ 322 ret__ = 0; \ 323 break; \ 324 } \ 325 if (expired__) { \ 326 ret__ = -ETIMEDOUT; \ 327 break; \ 328 } \ 329 usleep_range(wait__, wait__ * 2); \ 330 if (wait__ < (Wmax)) \ 331 wait__ <<= 1; \ 332 } \ 333 ret__; \ 334 }) 335 336 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \ 337 (Wmax)) 338 #define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000) 339 340 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */ 341 #if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT) 342 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic()) 343 #else 344 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0) 345 #endif 346 347 #define _wait_for_atomic(COND, US, ATOMIC) \ 348 ({ \ 349 int cpu, ret, timeout = (US) * 1000; \ 350 u64 base; \ 351 _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \ 352 if (!(ATOMIC)) { \ 353 preempt_disable(); \ 354 cpu = smp_processor_id(); \ 355 } \ 356 base = local_clock(); \ 357 for (;;) { \ 358 u64 now = local_clock(); \ 359 if (!(ATOMIC)) \ 360 preempt_enable(); \ 361 /* Guarantee COND check prior to timeout */ \ 362 barrier(); \ 363 if (COND) { \ 364 ret = 0; \ 365 break; \ 366 } \ 367 if (now - base >= timeout) { \ 368 ret = -ETIMEDOUT; \ 369 break; \ 370 } \ 371 cpu_relax(); \ 372 if (!(ATOMIC)) { \ 373 preempt_disable(); \ 374 if (unlikely(cpu != smp_processor_id())) { \ 375 timeout -= now - base; \ 376 cpu = smp_processor_id(); \ 377 base = local_clock(); \ 378 } \ 379 } \ 380 } \ 381 ret; \ 382 }) 383 384 #define wait_for_us(COND, US) \ 385 ({ \ 386 int ret__; \ 387 BUILD_BUG_ON(!__builtin_constant_p(US)); \ 388 if ((US) > 10) \ 389 ret__ = _wait_for((COND), (US), 10, 10); \ 390 else \ 391 ret__ = _wait_for_atomic((COND), (US), 0); \ 392 ret__; \ 393 }) 394 395 #define wait_for_atomic_us(COND, US) \ 396 ({ \ 397 BUILD_BUG_ON(!__builtin_constant_p(US)); \ 398 BUILD_BUG_ON((US) > 50000); \ 399 _wait_for_atomic((COND), (US), 1); \ 400 }) 401 402 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000) 403 404 #define KHz(x) (1000 * (x)) 405 #define MHz(x) KHz(1000 * (x)) 406 407 #define KBps(x) (1000 * (x)) 408 #define MBps(x) KBps(1000 * (x)) 409 #define GBps(x) ((u64)1000 * MBps((x))) 410 411 static inline const char *yesno(bool v) 412 { 413 return v ? "yes" : "no"; 414 } 415 416 static inline const char *onoff(bool v) 417 { 418 return v ? "on" : "off"; 419 } 420 421 static inline const char *enabledisable(bool v) 422 { 423 return v ? "enable" : "disable"; 424 } 425 426 static inline const char *enableddisabled(bool v) 427 { 428 return v ? "enabled" : "disabled"; 429 } 430 431 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint); 432 static inline void __add_taint_for_CI(unsigned int taint) 433 { 434 /* 435 * The system is "ok", just about surviving for the user, but 436 * CI results are now unreliable as the HW is very suspect. 437 * CI checks the taint state after every test and will reboot 438 * the machine if the kernel is tainted. 439 */ 440 add_taint(taint, LOCKDEP_STILL_OK); 441 } 442 443 void cancel_timer(struct timer_list *t); 444 void set_timer_ms(struct timer_list *t, unsigned long timeout); 445 446 static inline bool timer_active(const struct timer_list *t) 447 { 448 return READ_ONCE(t->expires); 449 } 450 451 static inline bool timer_expired(const struct timer_list *t) 452 { 453 return timer_active(t) && !timer_pending(t); 454 } 455 456 /* 457 * This is a lookalike for IS_ENABLED() that takes a kconfig value, 458 * e.g. CONFIG_DRM_I915_SPIN_REQUEST, and evaluates whether it is non-zero 459 * i.e. whether the configuration is active. Wrapping up the config inside 460 * a boolean context prevents clang and smatch from complaining about potential 461 * issues in confusing logical-&& with bitwise-& for constants. 462 * 463 * Sadly IS_ENABLED() itself does not work with kconfig values. 464 * 465 * Returns 0 if @config is 0, 1 if set to any value. 466 */ 467 #define IS_ACTIVE(config) ((config) != 0) 468 469 #endif /* !__I915_UTILS_H */ 470