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/string_helpers.h>
  32 #include <linux/types.h>
  33 #include <linux/workqueue.h>
  34 #include <linux/sched/clock.h>
  35
  36 #ifdef CONFIG_X86
  37 #include <asm/hypervisor.h>
  38 #endif
  39
  40 struct drm_i915_private;
  41 struct timer_list;
  42
  43 #define FDO_BUG_URL "https://gitlab.freedesktop.org/drm/intel/-/wikis/How-to-file-i915-bugs"
  44
  45 #define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
  46                              __stringify(x), (long)(x))
  47
  48 void __printf(3, 4)
  49 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
  50               const char *fmt, ...);
  51
  52 #define i915_report_error(dev_priv, fmt, ...)                              \
  53         __i915_printk(dev_priv, KERN_ERR, fmt, ##__VA_ARGS__)
  54
  55 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
  56
  57 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
  58                               const char *func, int line);
  59 #define i915_inject_probe_error(_i915, _err) \
  60         __i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
  61 bool i915_error_injected(void);
  62
  63 #else
  64
  65 #define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
  66 #define i915_error_injected() false
  67
  68 #endif
  69
  70 #define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
  71
  72 #define i915_probe_error(i915, fmt, ...)                                   \
  73         __i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \
  74                       fmt, ##__VA_ARGS__)
  75
  76 #if defined(GCC_VERSION) && GCC_VERSION >= 70000
  77 #define add_overflows_t(T, A, B) \
  78         __builtin_add_overflow_p((A), (B), (T)0)
  79 #else
  80 #define add_overflows_t(T, A, B) ({ \
  81         typeof(A) a = (A); \
  82         typeof(B) b = (B); \
  83         (T)(a + b) < a; \
  84 })
  85 #endif
  86
  87 #define add_overflows(A, B) \
  88         add_overflows_t(typeof((A) + (B)), (A), (B))
  89
  90 #define range_overflows(start, size, max) ({ \
  91         typeof(start) start__ = (start); \
  92         typeof(size) size__ = (size); \
  93         typeof(max) max__ = (max); \
  94         (void)(&start__ == &size__); \
  95         (void)(&start__ == &max__); \
  96         start__ >= max__ || size__ > max__ - start__; \
  97 })
  98
  99 #define range_overflows_t(type, start, size, max) \
 100         range_overflows((type)(start), (type)(size), (type)(max))
 101
 102 #define range_overflows_end(start, size, max) ({ \
 103         typeof(start) start__ = (start); \
 104         typeof(size) size__ = (size); \
 105         typeof(max) max__ = (max); \
 106         (void)(&start__ == &size__); \
 107         (void)(&start__ == &max__); \
 108         start__ > max__ || size__ > max__ - start__; \
 109 })
 110
 111 #define range_overflows_end_t(type, start, size, max) \
 112         range_overflows_end((type)(start), (type)(size), (type)(max))
 113
 114 /* Note we don't consider signbits :| */
 115 #define overflows_type(x, T) \
 116         (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))
 117
 118 static inline bool
 119 __check_struct_size(size_t base, size_t arr, size_t count, size_t *size)
 120 {
 121         size_t sz;
 122
 123         if (check_mul_overflow(count, arr, &sz))
 124                 return false;
 125
 126         if (check_add_overflow(sz, base, &sz))
 127                 return false;
 128
 129         *size = sz;
 130         return true;
 131 }
 132
 133 /**
 134  * check_struct_size() - Calculate size of structure with trailing array.
 135  * @p: Pointer to the structure.
 136  * @member: Name of the array member.
 137  * @n: Number of elements in the array.
 138  * @sz: Total size of structure and array
 139  *
 140  * Calculates size of memory needed for structure @p followed by an
 141  * array of @n @member elements, like struct_size() but reports
 142  * whether it overflowed, and the resultant size in @sz
 143  *
 144  * Return: false if the calculation overflowed.
 145  */
 146 #define check_struct_size(p, member, n, sz) \
 147         likely(__check_struct_size(sizeof(*(p)), \
 148                                    sizeof(*(p)->member) + __must_be_array((p)->member), \
 149                                    n, sz))
 150
 151 #define ptr_mask_bits(ptr, n) ({                                        \
 152         unsigned long __v = (unsigned long)(ptr);                       \
 153         (typeof(ptr))(__v & -BIT(n));                                   \
 154 })
 155
 156 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
 157
 158 #define ptr_unpack_bits(ptr, bits, n) ({                                \
 159         unsigned long __v = (unsigned long)(ptr);                       \
 160         *(bits) = __v & (BIT(n) - 1);                                   \
 161         (typeof(ptr))(__v & -BIT(n));                                   \
 162 })
 163
 164 #define ptr_pack_bits(ptr, bits, n) ({                                  \
 165         unsigned long __bits = (bits);                                  \
 166         GEM_BUG_ON(__bits & -BIT(n));                                   \
 167         ((typeof(ptr))((unsigned long)(ptr) | __bits));                 \
 168 })
 169
 170 #define ptr_dec(ptr) ({                                                 \
 171         unsigned long __v = (unsigned long)(ptr);                       \
 172         (typeof(ptr))(__v - 1);                                         \
 173 })
 174
 175 #define ptr_inc(ptr) ({                                                 \
 176         unsigned long __v = (unsigned long)(ptr);                       \
 177         (typeof(ptr))(__v + 1);                                         \
 178 })
 179
 180 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
 181 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
 182 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
 183 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
 184
 185 #define struct_member(T, member) (((T *)0)->member)
 186
 187 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
 188
 189 #define fetch_and_zero(ptr) ({                                          \
 190         typeof(*ptr) __T = *(ptr);                                      \
 191         *(ptr) = (typeof(*ptr))0;                                       \
 192         __T;                                                            \
 193 })
 194
 195 static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
 196 {
 197         return a - b;
 198 }
 199
 200 /*
 201  * container_of_user: Extract the superclass from a pointer to a member.
 202  *
 203  * Exactly like container_of() with the exception that it plays nicely
 204  * with sparse for __user @ptr.
 205  */
 206 #define container_of_user(ptr, type, member) ({                         \
 207         void __user *__mptr = (void __user *)(ptr);                     \
 208         BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
 209                          !__same_type(*(ptr), void),                    \
 210                          "pointer type mismatch in container_of()");    \
 211         ((type __user *)(__mptr - offsetof(type, member))); })
 212
 213 /*
 214  * check_user_mbz: Check that a user value exists and is zero
 215  *
 216  * Frequently in our uABI we reserve space for future extensions, and
 217  * two ensure that userspace is prepared we enforce that space must
 218  * be zero. (Then any future extension can safely assume a default value
 219  * of 0.)
 220  *
 221  * check_user_mbz() combines checking that the user pointer is accessible
 222  * and that the contained value is zero.
 223  *
 224  * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
 225  */
 226 #define check_user_mbz(U) ({                                            \
 227         typeof(*(U)) mbz__;                                             \
 228         get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;           \
 229 })
 230
 231 static inline u64 ptr_to_u64(const void *ptr)
 232 {
 233         return (uintptr_t)ptr;
 234 }
 235
 236 #define u64_to_ptr(T, x) ({                                             \
 237         typecheck(u64, x);                                              \
 238         (T *)(uintptr_t)(x);                                            \
 239 })
 240
 241 #define __mask_next_bit(mask) ({                                        \
 242         int __idx = ffs(mask) - 1;                                      \
 243         mask &= ~BIT(__idx);                                            \
 244         __idx;                                                          \
 245 })
 246
 247 static inline bool is_power_of_2_u64(u64 n)
 248 {
 249         return (n != 0 && ((n & (n - 1)) == 0));
 250 }
 251
 252 static inline void __list_del_many(struct list_head *head,
 253                                    struct list_head *first)
 254 {
 255         first->prev = head;
 256         WRITE_ONCE(head->next, first);
 257 }
 258
 259 static inline int list_is_last_rcu(const struct list_head *list,
 260                                    const struct list_head *head)
 261 {
 262         return READ_ONCE(list->next) == head;
 263 }
 264
 265 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
 266 {
 267         unsigned long j = msecs_to_jiffies(m);
 268
 269         return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
 270 }
 271
 272 /*
 273  * If you need to wait X milliseconds between events A and B, but event B
 274  * doesn't happen exactly after event A, you record the timestamp (jiffies) of
 275  * when event A happened, then just before event B you call this function and
 276  * pass the timestamp as the first argument, and X as the second argument.
 277  */
 278 static inline void
 279 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 280 {
 281         unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
 282
 283         /*
 284          * Don't re-read the value of "jiffies" every time since it may change
 285          * behind our back and break the math.
 286          */
 287         tmp_jiffies = jiffies;
 288         target_jiffies = timestamp_jiffies +
 289                          msecs_to_jiffies_timeout(to_wait_ms);
 290
 291         if (time_after(target_jiffies, tmp_jiffies)) {
 292                 remaining_jiffies = target_jiffies - tmp_jiffies;
 293                 while (remaining_jiffies)
 294                         remaining_jiffies =
 295                             schedule_timeout_uninterruptible(remaining_jiffies);
 296         }
 297 }
 298
 299 /**
 300  * __wait_for - magic wait macro
 301  *
 302  * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
 303  * important that we check the condition again after having timed out, since the
 304  * timeout could be due to preemption or similar and we've never had a chance to
 305  * check the condition before the timeout.
 306  */
 307 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
 308         const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
 309         long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
 310         int ret__;                                                      \
 311         might_sleep();                                                  \
 312         for (;;) {                                                      \
 313                 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
 314                 OP;                                                     \
 315                 /* Guarantee COND check prior to timeout */             \
 316                 barrier();                                              \
 317                 if (COND) {                                             \
 318                         ret__ = 0;                                      \
 319                         break;                                          \
 320                 }                                                       \
 321                 if (expired__) {                                        \
 322                         ret__ = -ETIMEDOUT;                             \
 323                         break;                                          \
 324                 }                                                       \
 325                 usleep_range(wait__, wait__ * 2);                       \
 326                 if (wait__ < (Wmax))                                    \
 327                         wait__ <<= 1;                                   \
 328         }                                                               \
 329         ret__;                                                          \
 330 })
 331
 332 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
 333                                                    (Wmax))
 334 #define wait_for(COND, MS)              _wait_for((COND), (MS) * 1000, 10, 1000)
 335
 336 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
 337 #if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
 338 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
 339 #else
 340 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
 341 #endif
 342
 343 #define _wait_for_atomic(COND, US, ATOMIC) \
 344 ({ \
 345         int cpu, ret, timeout = (US) * 1000; \
 346         u64 base; \
 347         _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
 348         if (!(ATOMIC)) { \
 349                 preempt_disable(); \
 350                 cpu = smp_processor_id(); \
 351         } \
 352         base = local_clock(); \
 353         for (;;) { \
 354                 u64 now = local_clock(); \
 355                 if (!(ATOMIC)) \
 356                         preempt_enable(); \
 357                 /* Guarantee COND check prior to timeout */ \
 358                 barrier(); \
 359                 if (COND) { \
 360                         ret = 0; \
 361                         break; \
 362                 } \
 363                 if (now - base >= timeout) { \
 364                         ret = -ETIMEDOUT; \
 365                         break; \
 366                 } \
 367                 cpu_relax(); \
 368                 if (!(ATOMIC)) { \
 369                         preempt_disable(); \
 370                         if (unlikely(cpu != smp_processor_id())) { \
 371                                 timeout -= now - base; \
 372                                 cpu = smp_processor_id(); \
 373                                 base = local_clock(); \
 374                         } \
 375                 } \
 376         } \
 377         ret; \
 378 })
 379
 380 #define wait_for_us(COND, US) \
 381 ({ \
 382         int ret__; \
 383         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 384         if ((US) > 10) \
 385                 ret__ = _wait_for((COND), (US), 10, 10); \
 386         else \
 387                 ret__ = _wait_for_atomic((COND), (US), 0); \
 388         ret__; \
 389 })
 390
 391 #define wait_for_atomic_us(COND, US) \
 392 ({ \
 393         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 394         BUILD_BUG_ON((US) > 50000); \
 395         _wait_for_atomic((COND), (US), 1); \
 396 })
 397
 398 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
 399
 400 #define KHz(x) (1000 * (x))
 401 #define MHz(x) KHz(1000 * (x))
 402
 403 #define KBps(x) (1000 * (x))
 404 #define MBps(x) KBps(1000 * (x))
 405 #define GBps(x) ((u64)1000 * MBps((x)))
 406
 407 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
 408 static inline void __add_taint_for_CI(unsigned int taint)
 409 {
 410         /*
 411          * The system is "ok", just about surviving for the user, but
 412          * CI results are now unreliable as the HW is very suspect.
 413          * CI checks the taint state after every test and will reboot
 414          * the machine if the kernel is tainted.
 415          */
 416         add_taint(taint, LOCKDEP_STILL_OK);
 417 }
 418
 419 void cancel_timer(struct timer_list *t);
 420 void set_timer_ms(struct timer_list *t, unsigned long timeout);
 421
 422 static inline bool timer_active(const struct timer_list *t)
 423 {
 424         return READ_ONCE(t->expires);
 425 }
 426
 427 static inline bool timer_expired(const struct timer_list *t)
 428 {
 429         return timer_active(t) && !timer_pending(t);
 430 }
 431
 432 static inline bool i915_run_as_guest(void)
 433 {
 434 #if IS_ENABLED(CONFIG_X86)
 435         return !hypervisor_is_type(X86_HYPER_NATIVE);
 436 #else
 437         /* Not supported yet */
 438         return false;
 439 #endif
 440 }
 441
 442 bool i915_vtd_active(struct drm_i915_private *i915);
 443
 444 #endif /* !__I915_UTILS_H */