drivers/gpu/drm/i915/i915_utils.h

   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 */