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://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html"
  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 #define range_overflows(start, size, max) ({ \
  77         typeof(start) start__ = (start); \
  78         typeof(size) size__ = (size); \
  79         typeof(max) max__ = (max); \
  80         (void)(&start__ == &size__); \
  81         (void)(&start__ == &max__); \
  82         start__ >= max__ || size__ > max__ - start__; \
  83 })
  84
  85 #define range_overflows_t(type, start, size, max) \
  86         range_overflows((type)(start), (type)(size), (type)(max))
  87
  88 #define range_overflows_end(start, size, max) ({ \
  89         typeof(start) start__ = (start); \
  90         typeof(size) size__ = (size); \
  91         typeof(max) max__ = (max); \
  92         (void)(&start__ == &size__); \
  93         (void)(&start__ == &max__); \
  94         start__ > max__ || size__ > max__ - start__; \
  95 })
  96
  97 #define range_overflows_end_t(type, start, size, max) \
  98         range_overflows_end((type)(start), (type)(size), (type)(max))
  99
 100 #define ptr_mask_bits(ptr, n) ({                                        \
 101         unsigned long __v = (unsigned long)(ptr);                       \
 102         (typeof(ptr))(__v & -BIT(n));                                   \
 103 })
 104
 105 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
 106
 107 #define ptr_unpack_bits(ptr, bits, n) ({                                \
 108         unsigned long __v = (unsigned long)(ptr);                       \
 109         *(bits) = __v & (BIT(n) - 1);                                   \
 110         (typeof(ptr))(__v & -BIT(n));                                   \
 111 })
 112
 113 #define ptr_pack_bits(ptr, bits, n) ({                                  \
 114         unsigned long __bits = (bits);                                  \
 115         GEM_BUG_ON(__bits & -BIT(n));                                   \
 116         ((typeof(ptr))((unsigned long)(ptr) | __bits));                 \
 117 })
 118
 119 #define ptr_dec(ptr) ({                                                 \
 120         unsigned long __v = (unsigned long)(ptr);                       \
 121         (typeof(ptr))(__v - 1);                                         \
 122 })
 123
 124 #define ptr_inc(ptr) ({                                                 \
 125         unsigned long __v = (unsigned long)(ptr);                       \
 126         (typeof(ptr))(__v + 1);                                         \
 127 })
 128
 129 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
 130 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
 131 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
 132 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
 133
 134 #define fetch_and_zero(ptr) ({                                          \
 135         typeof(*ptr) __T = *(ptr);                                      \
 136         *(ptr) = (typeof(*ptr))0;                                       \
 137         __T;                                                            \
 138 })
 139
 140 static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
 141 {
 142         return a - b;
 143 }
 144
 145 /*
 146  * container_of_user: Extract the superclass from a pointer to a member.
 147  *
 148  * Exactly like container_of() with the exception that it plays nicely
 149  * with sparse for __user @ptr.
 150  */
 151 #define container_of_user(ptr, type, member) ({                         \
 152         void __user *__mptr = (void __user *)(ptr);                     \
 153         BUILD_BUG_ON_MSG(!__same_type(*(ptr), typeof_member(type, member)) && \
 154                          !__same_type(*(ptr), void),                    \
 155                          "pointer type mismatch in container_of()");    \
 156         ((type __user *)(__mptr - offsetof(type, member))); })
 157
 158 /*
 159  * check_user_mbz: Check that a user value exists and is zero
 160  *
 161  * Frequently in our uABI we reserve space for future extensions, and
 162  * two ensure that userspace is prepared we enforce that space must
 163  * be zero. (Then any future extension can safely assume a default value
 164  * of 0.)
 165  *
 166  * check_user_mbz() combines checking that the user pointer is accessible
 167  * and that the contained value is zero.
 168  *
 169  * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
 170  */
 171 #define check_user_mbz(U) ({                                            \
 172         typeof(*(U)) mbz__;                                             \
 173         get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;           \
 174 })
 175
 176 #define u64_to_ptr(T, x) ({                                             \
 177         typecheck(u64, x);                                              \
 178         (T *)(uintptr_t)(x);                                            \
 179 })
 180
 181 #define __mask_next_bit(mask) ({                                        \
 182         int __idx = ffs(mask) - 1;                                      \
 183         mask &= ~BIT(__idx);                                            \
 184         __idx;                                                          \
 185 })
 186
 187 static inline bool is_power_of_2_u64(u64 n)
 188 {
 189         return (n != 0 && ((n & (n - 1)) == 0));
 190 }
 191
 192 static inline void __list_del_many(struct list_head *head,
 193                                    struct list_head *first)
 194 {
 195         first->prev = head;
 196         WRITE_ONCE(head->next, first);
 197 }
 198
 199 static inline int list_is_last_rcu(const struct list_head *list,
 200                                    const struct list_head *head)
 201 {
 202         return READ_ONCE(list->next) == head;
 203 }
 204
 205 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
 206 {
 207         unsigned long j = msecs_to_jiffies(m);
 208
 209         return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
 210 }
 211
 212 /*
 213  * If you need to wait X milliseconds between events A and B, but event B
 214  * doesn't happen exactly after event A, you record the timestamp (jiffies) of
 215  * when event A happened, then just before event B you call this function and
 216  * pass the timestamp as the first argument, and X as the second argument.
 217  */
 218 static inline void
 219 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 220 {
 221         unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
 222
 223         /*
 224          * Don't re-read the value of "jiffies" every time since it may change
 225          * behind our back and break the math.
 226          */
 227         tmp_jiffies = jiffies;
 228         target_jiffies = timestamp_jiffies +
 229                          msecs_to_jiffies_timeout(to_wait_ms);
 230
 231         if (time_after(target_jiffies, tmp_jiffies)) {
 232                 remaining_jiffies = target_jiffies - tmp_jiffies;
 233                 while (remaining_jiffies)
 234                         remaining_jiffies =
 235                             schedule_timeout_uninterruptible(remaining_jiffies);
 236         }
 237 }
 238
 239 /*
 240  * __wait_for - magic wait macro
 241  *
 242  * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
 243  * important that we check the condition again after having timed out, since the
 244  * timeout could be due to preemption or similar and we've never had a chance to
 245  * check the condition before the timeout.
 246  */
 247 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
 248         const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
 249         long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
 250         int ret__;                                                      \
 251         might_sleep();                                                  \
 252         for (;;) {                                                      \
 253                 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
 254                 OP;                                                     \
 255                 /* Guarantee COND check prior to timeout */             \
 256                 barrier();                                              \
 257                 if (COND) {                                             \
 258                         ret__ = 0;                                      \
 259                         break;                                          \
 260                 }                                                       \
 261                 if (expired__) {                                        \
 262                         ret__ = -ETIMEDOUT;                             \
 263                         break;                                          \
 264                 }                                                       \
 265                 usleep_range(wait__, wait__ * 2);                       \
 266                 if (wait__ < (Wmax))                                    \
 267                         wait__ <<= 1;                                   \
 268         }                                                               \
 269         ret__;                                                          \
 270 })
 271
 272 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
 273                                                    (Wmax))
 274 #define wait_for(COND, MS)              _wait_for((COND), (MS) * 1000, 10, 1000)
 275
 276 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
 277 #if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
 278 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
 279 #else
 280 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
 281 #endif
 282
 283 #define _wait_for_atomic(COND, US, ATOMIC) \
 284 ({ \
 285         int cpu, ret, timeout = (US) * 1000; \
 286         u64 base; \
 287         _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
 288         if (!(ATOMIC)) { \
 289                 preempt_disable(); \
 290                 cpu = smp_processor_id(); \
 291         } \
 292         base = local_clock(); \
 293         for (;;) { \
 294                 u64 now = local_clock(); \
 295                 if (!(ATOMIC)) \
 296                         preempt_enable(); \
 297                 /* Guarantee COND check prior to timeout */ \
 298                 barrier(); \
 299                 if (COND) { \
 300                         ret = 0; \
 301                         break; \
 302                 } \
 303                 if (now - base >= timeout) { \
 304                         ret = -ETIMEDOUT; \
 305                         break; \
 306                 } \
 307                 cpu_relax(); \
 308                 if (!(ATOMIC)) { \
 309                         preempt_disable(); \
 310                         if (unlikely(cpu != smp_processor_id())) { \
 311                                 timeout -= now - base; \
 312                                 cpu = smp_processor_id(); \
 313                                 base = local_clock(); \
 314                         } \
 315                 } \
 316         } \
 317         ret; \
 318 })
 319
 320 #define wait_for_us(COND, US) \
 321 ({ \
 322         int ret__; \
 323         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 324         if ((US) > 10) \
 325                 ret__ = _wait_for((COND), (US), 10, 10); \
 326         else \
 327                 ret__ = _wait_for_atomic((COND), (US), 0); \
 328         ret__; \
 329 })
 330
 331 #define wait_for_atomic_us(COND, US) \
 332 ({ \
 333         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 334         BUILD_BUG_ON((US) > 50000); \
 335         _wait_for_atomic((COND), (US), 1); \
 336 })
 337
 338 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
 339
 340 #define KHz(x) (1000 * (x))
 341 #define MHz(x) KHz(1000 * (x))
 342
 343 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
 344 static inline void __add_taint_for_CI(unsigned int taint)
 345 {
 346         /*
 347          * The system is "ok", just about surviving for the user, but
 348          * CI results are now unreliable as the HW is very suspect.
 349          * CI checks the taint state after every test and will reboot
 350          * the machine if the kernel is tainted.
 351          */
 352         add_taint(taint, LOCKDEP_STILL_OK);
 353 }
 354
 355 void cancel_timer(struct timer_list *t);
 356 void set_timer_ms(struct timer_list *t, unsigned long timeout);
 357
 358 static inline bool timer_active(const struct timer_list *t)
 359 {
 360         return READ_ONCE(t->expires);
 361 }
 362
 363 static inline bool timer_expired(const struct timer_list *t)
 364 {
 365         return timer_active(t) && !timer_pending(t);
 366 }
 367
 368 static inline bool i915_run_as_guest(void)
 369 {
 370 #if IS_ENABLED(CONFIG_X86)
 371         return !hypervisor_is_type(X86_HYPER_NATIVE);
 372 #else
 373         /* Not supported yet */
 374         return false;
 375 #endif
 376 }
 377
 378 bool i915_vtd_active(struct drm_i915_private *i915);
 379
 380 bool i915_direct_stolen_access(struct drm_i915_private *i915);
 381
 382 #endif /* !__I915_UTILS_H */