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 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
  49
  50 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
  51                               const char *func, int line);
  52 #define i915_inject_probe_error(_i915, _err) \
  53         __i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
  54 bool i915_error_injected(void);
  55
  56 #else
  57
  58 #define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
  59 #define i915_error_injected() false
  60
  61 #endif
  62
  63 #define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
  64
  65 #define i915_probe_error(i915, fmt, ...) ({ \
  66         if (i915_error_injected()) \
  67                 drm_dbg(&(i915)->drm, fmt, ##__VA_ARGS__); \
  68         else \
  69                 drm_err(&(i915)->drm, fmt, ##__VA_ARGS__); \
  70 })
  71
  72 #define range_overflows(start, size, max) ({ \
  73         typeof(start) start__ = (start); \
  74         typeof(size) size__ = (size); \
  75         typeof(max) max__ = (max); \
  76         (void)(&start__ == &size__); \
  77         (void)(&start__ == &max__); \
  78         start__ >= max__ || size__ > max__ - start__; \
  79 })
  80
  81 #define range_overflows_t(type, start, size, max) \
  82         range_overflows((type)(start), (type)(size), (type)(max))
  83
  84 #define range_overflows_end(start, size, max) ({ \
  85         typeof(start) start__ = (start); \
  86         typeof(size) size__ = (size); \
  87         typeof(max) max__ = (max); \
  88         (void)(&start__ == &size__); \
  89         (void)(&start__ == &max__); \
  90         start__ > max__ || size__ > max__ - start__; \
  91 })
  92
  93 #define range_overflows_end_t(type, start, size, max) \
  94         range_overflows_end((type)(start), (type)(size), (type)(max))
  95
  96 #define ptr_mask_bits(ptr, n) ({                                        \
  97         unsigned long __v = (unsigned long)(ptr);                       \
  98         (typeof(ptr))(__v & -BIT(n));                                   \
  99 })
 100
 101 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
 102
 103 #define ptr_unpack_bits(ptr, bits, n) ({                                \
 104         unsigned long __v = (unsigned long)(ptr);                       \
 105         *(bits) = __v & (BIT(n) - 1);                                   \
 106         (typeof(ptr))(__v & -BIT(n));                                   \
 107 })
 108
 109 #define ptr_pack_bits(ptr, bits, n) ({                                  \
 110         unsigned long __bits = (bits);                                  \
 111         GEM_BUG_ON(__bits & -BIT(n));                                   \
 112         ((typeof(ptr))((unsigned long)(ptr) | __bits));                 \
 113 })
 114
 115 #define ptr_dec(ptr) ({                                                 \
 116         unsigned long __v = (unsigned long)(ptr);                       \
 117         (typeof(ptr))(__v - 1);                                         \
 118 })
 119
 120 #define ptr_inc(ptr) ({                                                 \
 121         unsigned long __v = (unsigned long)(ptr);                       \
 122         (typeof(ptr))(__v + 1);                                         \
 123 })
 124
 125 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
 126 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
 127 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
 128 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
 129
 130 #define fetch_and_zero(ptr) ({                                          \
 131         typeof(*ptr) __T = *(ptr);                                      \
 132         *(ptr) = (typeof(*ptr))0;                                       \
 133         __T;                                                            \
 134 })
 135
 136 static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
 137 {
 138         return a - b;
 139 }
 140
 141 /*
 142  * container_of_user: Extract the superclass from a pointer to a member.
 143  *
 144  * Exactly like container_of() with the exception that it plays nicely
 145  * with sparse for __user @ptr.
 146  */
 147 #define container_of_user(ptr, type, member) ({                         \
 148         void __user *__mptr = (void __user *)(ptr);                     \
 149         BUILD_BUG_ON_MSG(!__same_type(*(ptr), typeof_member(type, member)) && \
 150                          !__same_type(*(ptr), void),                    \
 151                          "pointer type mismatch in container_of()");    \
 152         ((type __user *)(__mptr - offsetof(type, member))); })
 153
 154 /*
 155  * check_user_mbz: Check that a user value exists and is zero
 156  *
 157  * Frequently in our uABI we reserve space for future extensions, and
 158  * two ensure that userspace is prepared we enforce that space must
 159  * be zero. (Then any future extension can safely assume a default value
 160  * of 0.)
 161  *
 162  * check_user_mbz() combines checking that the user pointer is accessible
 163  * and that the contained value is zero.
 164  *
 165  * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
 166  */
 167 #define check_user_mbz(U) ({                                            \
 168         typeof(*(U)) mbz__;                                             \
 169         get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;           \
 170 })
 171
 172 #define u64_to_ptr(T, x) ({                                             \
 173         typecheck(u64, x);                                              \
 174         (T *)(uintptr_t)(x);                                            \
 175 })
 176
 177 #define __mask_next_bit(mask) ({                                        \
 178         int __idx = ffs(mask) - 1;                                      \
 179         mask &= ~BIT(__idx);                                            \
 180         __idx;                                                          \
 181 })
 182
 183 static inline bool is_power_of_2_u64(u64 n)
 184 {
 185         return (n != 0 && ((n & (n - 1)) == 0));
 186 }
 187
 188 static inline void __list_del_many(struct list_head *head,
 189                                    struct list_head *first)
 190 {
 191         first->prev = head;
 192         WRITE_ONCE(head->next, first);
 193 }
 194
 195 static inline int list_is_last_rcu(const struct list_head *list,
 196                                    const struct list_head *head)
 197 {
 198         return READ_ONCE(list->next) == head;
 199 }
 200
 201 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
 202 {
 203         unsigned long j = msecs_to_jiffies(m);
 204
 205         return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
 206 }
 207
 208 /*
 209  * If you need to wait X milliseconds between events A and B, but event B
 210  * doesn't happen exactly after event A, you record the timestamp (jiffies) of
 211  * when event A happened, then just before event B you call this function and
 212  * pass the timestamp as the first argument, and X as the second argument.
 213  */
 214 static inline void
 215 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 216 {
 217         unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
 218
 219         /*
 220          * Don't re-read the value of "jiffies" every time since it may change
 221          * behind our back and break the math.
 222          */
 223         tmp_jiffies = jiffies;
 224         target_jiffies = timestamp_jiffies +
 225                          msecs_to_jiffies_timeout(to_wait_ms);
 226
 227         if (time_after(target_jiffies, tmp_jiffies)) {
 228                 remaining_jiffies = target_jiffies - tmp_jiffies;
 229                 while (remaining_jiffies)
 230                         remaining_jiffies =
 231                             schedule_timeout_uninterruptible(remaining_jiffies);
 232         }
 233 }
 234
 235 /*
 236  * __wait_for - magic wait macro
 237  *
 238  * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
 239  * important that we check the condition again after having timed out, since the
 240  * timeout could be due to preemption or similar and we've never had a chance to
 241  * check the condition before the timeout.
 242  */
 243 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
 244         const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
 245         long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
 246         int ret__;                                                      \
 247         might_sleep();                                                  \
 248         for (;;) {                                                      \
 249                 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
 250                 OP;                                                     \
 251                 /* Guarantee COND check prior to timeout */             \
 252                 barrier();                                              \
 253                 if (COND) {                                             \
 254                         ret__ = 0;                                      \
 255                         break;                                          \
 256                 }                                                       \
 257                 if (expired__) {                                        \
 258                         ret__ = -ETIMEDOUT;                             \
 259                         break;                                          \
 260                 }                                                       \
 261                 usleep_range(wait__, wait__ * 2);                       \
 262                 if (wait__ < (Wmax))                                    \
 263                         wait__ <<= 1;                                   \
 264         }                                                               \
 265         ret__;                                                          \
 266 })
 267
 268 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
 269                                                    (Wmax))
 270 #define wait_for(COND, MS)              _wait_for((COND), (MS) * 1000, 10, 1000)
 271
 272 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
 273 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG) && IS_ENABLED(CONFIG_PREEMPT_COUNT)
 274 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
 275 #else
 276 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
 277 #endif
 278
 279 #define _wait_for_atomic(COND, US, ATOMIC) \
 280 ({ \
 281         int cpu, ret, timeout = (US) * 1000; \
 282         u64 base; \
 283         _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
 284         if (!(ATOMIC)) { \
 285                 preempt_disable(); \
 286                 cpu = smp_processor_id(); \
 287         } \
 288         base = local_clock(); \
 289         for (;;) { \
 290                 u64 now = local_clock(); \
 291                 if (!(ATOMIC)) \
 292                         preempt_enable(); \
 293                 /* Guarantee COND check prior to timeout */ \
 294                 barrier(); \
 295                 if (COND) { \
 296                         ret = 0; \
 297                         break; \
 298                 } \
 299                 if (now - base >= timeout) { \
 300                         ret = -ETIMEDOUT; \
 301                         break; \
 302                 } \
 303                 cpu_relax(); \
 304                 if (!(ATOMIC)) { \
 305                         preempt_disable(); \
 306                         if (unlikely(cpu != smp_processor_id())) { \
 307                                 timeout -= now - base; \
 308                                 cpu = smp_processor_id(); \
 309                                 base = local_clock(); \
 310                         } \
 311                 } \
 312         } \
 313         ret; \
 314 })
 315
 316 #define wait_for_us(COND, US) \
 317 ({ \
 318         int ret__; \
 319         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 320         if ((US) > 10) \
 321                 ret__ = _wait_for((COND), (US), 10, 10); \
 322         else \
 323                 ret__ = _wait_for_atomic((COND), (US), 0); \
 324         ret__; \
 325 })
 326
 327 #define wait_for_atomic_us(COND, US) \
 328 ({ \
 329         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 330         BUILD_BUG_ON((US) > 50000); \
 331         _wait_for_atomic((COND), (US), 1); \
 332 })
 333
 334 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
 335
 336 #define KHz(x) (1000 * (x))
 337 #define MHz(x) KHz(1000 * (x))
 338
 339 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
 340 static inline void __add_taint_for_CI(unsigned int taint)
 341 {
 342         /*
 343          * The system is "ok", just about surviving for the user, but
 344          * CI results are now unreliable as the HW is very suspect.
 345          * CI checks the taint state after every test and will reboot
 346          * the machine if the kernel is tainted.
 347          */
 348         add_taint(taint, LOCKDEP_STILL_OK);
 349 }
 350
 351 void cancel_timer(struct timer_list *t);
 352 void set_timer_ms(struct timer_list *t, unsigned long timeout);
 353
 354 static inline bool timer_active(const struct timer_list *t)
 355 {
 356         return READ_ONCE(t->expires);
 357 }
 358
 359 static inline bool timer_expired(const struct timer_list *t)
 360 {
 361         return timer_active(t) && !timer_pending(t);
 362 }
 363
 364 static inline bool i915_run_as_guest(void)
 365 {
 366 #if IS_ENABLED(CONFIG_X86)
 367         return !hypervisor_is_type(X86_HYPER_NATIVE);
 368 #else
 369         /* Not supported yet */
 370         return false;
 371 #endif
 372 }
 373
 374 bool i915_vtd_active(struct drm_i915_private *i915);
 375
 376 bool i915_direct_stolen_access(struct drm_i915_private *i915);
 377
 378 #endif /* !__I915_UTILS_H */