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