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 #define ptr_mask_bits(ptr, n) ({                                        \
 115         unsigned long __v = (unsigned long)(ptr);                       \
 116         (typeof(ptr))(__v & -BIT(n));                                   \
 117 })
 118
 119 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
 120
 121 #define ptr_unpack_bits(ptr, bits, n) ({                                \
 122         unsigned long __v = (unsigned long)(ptr);                       \
 123         *(bits) = __v & (BIT(n) - 1);                                   \
 124         (typeof(ptr))(__v & -BIT(n));                                   \
 125 })
 126
 127 #define ptr_pack_bits(ptr, bits, n) ({                                  \
 128         unsigned long __bits = (bits);                                  \
 129         GEM_BUG_ON(__bits & -BIT(n));                                   \
 130         ((typeof(ptr))((unsigned long)(ptr) | __bits));                 \
 131 })
 132
 133 #define ptr_dec(ptr) ({                                                 \
 134         unsigned long __v = (unsigned long)(ptr);                       \
 135         (typeof(ptr))(__v - 1);                                         \
 136 })
 137
 138 #define ptr_inc(ptr) ({                                                 \
 139         unsigned long __v = (unsigned long)(ptr);                       \
 140         (typeof(ptr))(__v + 1);                                         \
 141 })
 142
 143 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
 144 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
 145 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
 146 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
 147
 148 #define fetch_and_zero(ptr) ({                                          \
 149         typeof(*ptr) __T = *(ptr);                                      \
 150         *(ptr) = (typeof(*ptr))0;                                       \
 151         __T;                                                            \
 152 })
 153
 154 static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
 155 {
 156         return a - b;
 157 }
 158
 159 /*
 160  * container_of_user: Extract the superclass from a pointer to a member.
 161  *
 162  * Exactly like container_of() with the exception that it plays nicely
 163  * with sparse for __user @ptr.
 164  */
 165 #define container_of_user(ptr, type, member) ({                         \
 166         void __user *__mptr = (void __user *)(ptr);                     \
 167         BUILD_BUG_ON_MSG(!__same_type(*(ptr), typeof_member(type, member)) && \
 168                          !__same_type(*(ptr), void),                    \
 169                          "pointer type mismatch in container_of()");    \
 170         ((type __user *)(__mptr - offsetof(type, member))); })
 171
 172 /*
 173  * check_user_mbz: Check that a user value exists and is zero
 174  *
 175  * Frequently in our uABI we reserve space for future extensions, and
 176  * two ensure that userspace is prepared we enforce that space must
 177  * be zero. (Then any future extension can safely assume a default value
 178  * of 0.)
 179  *
 180  * check_user_mbz() combines checking that the user pointer is accessible
 181  * and that the contained value is zero.
 182  *
 183  * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
 184  */
 185 #define check_user_mbz(U) ({                                            \
 186         typeof(*(U)) mbz__;                                             \
 187         get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;           \
 188 })
 189
 190 #define u64_to_ptr(T, x) ({                                             \
 191         typecheck(u64, x);                                              \
 192         (T *)(uintptr_t)(x);                                            \
 193 })
 194
 195 #define __mask_next_bit(mask) ({                                        \
 196         int __idx = ffs(mask) - 1;                                      \
 197         mask &= ~BIT(__idx);                                            \
 198         __idx;                                                          \
 199 })
 200
 201 static inline bool is_power_of_2_u64(u64 n)
 202 {
 203         return (n != 0 && ((n & (n - 1)) == 0));
 204 }
 205
 206 static inline void __list_del_many(struct list_head *head,
 207                                    struct list_head *first)
 208 {
 209         first->prev = head;
 210         WRITE_ONCE(head->next, first);
 211 }
 212
 213 static inline int list_is_last_rcu(const struct list_head *list,
 214                                    const struct list_head *head)
 215 {
 216         return READ_ONCE(list->next) == head;
 217 }
 218
 219 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
 220 {
 221         unsigned long j = msecs_to_jiffies(m);
 222
 223         return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
 224 }
 225
 226 /*
 227  * If you need to wait X milliseconds between events A and B, but event B
 228  * doesn't happen exactly after event A, you record the timestamp (jiffies) of
 229  * when event A happened, then just before event B you call this function and
 230  * pass the timestamp as the first argument, and X as the second argument.
 231  */
 232 static inline void
 233 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 234 {
 235         unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
 236
 237         /*
 238          * Don't re-read the value of "jiffies" every time since it may change
 239          * behind our back and break the math.
 240          */
 241         tmp_jiffies = jiffies;
 242         target_jiffies = timestamp_jiffies +
 243                          msecs_to_jiffies_timeout(to_wait_ms);
 244
 245         if (time_after(target_jiffies, tmp_jiffies)) {
 246                 remaining_jiffies = target_jiffies - tmp_jiffies;
 247                 while (remaining_jiffies)
 248                         remaining_jiffies =
 249                             schedule_timeout_uninterruptible(remaining_jiffies);
 250         }
 251 }
 252
 253 /**
 254  * __wait_for - magic wait macro
 255  *
 256  * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
 257  * important that we check the condition again after having timed out, since the
 258  * timeout could be due to preemption or similar and we've never had a chance to
 259  * check the condition before the timeout.
 260  */
 261 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
 262         const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
 263         long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
 264         int ret__;                                                      \
 265         might_sleep();                                                  \
 266         for (;;) {                                                      \
 267                 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
 268                 OP;                                                     \
 269                 /* Guarantee COND check prior to timeout */             \
 270                 barrier();                                              \
 271                 if (COND) {                                             \
 272                         ret__ = 0;                                      \
 273                         break;                                          \
 274                 }                                                       \
 275                 if (expired__) {                                        \
 276                         ret__ = -ETIMEDOUT;                             \
 277                         break;                                          \
 278                 }                                                       \
 279                 usleep_range(wait__, wait__ * 2);                       \
 280                 if (wait__ < (Wmax))                                    \
 281                         wait__ <<= 1;                                   \
 282         }                                                               \
 283         ret__;                                                          \
 284 })
 285
 286 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
 287                                                    (Wmax))
 288 #define wait_for(COND, MS)              _wait_for((COND), (MS) * 1000, 10, 1000)
 289
 290 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
 291 #if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
 292 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
 293 #else
 294 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
 295 #endif
 296
 297 #define _wait_for_atomic(COND, US, ATOMIC) \
 298 ({ \
 299         int cpu, ret, timeout = (US) * 1000; \
 300         u64 base; \
 301         _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
 302         if (!(ATOMIC)) { \
 303                 preempt_disable(); \
 304                 cpu = smp_processor_id(); \
 305         } \
 306         base = local_clock(); \
 307         for (;;) { \
 308                 u64 now = local_clock(); \
 309                 if (!(ATOMIC)) \
 310                         preempt_enable(); \
 311                 /* Guarantee COND check prior to timeout */ \
 312                 barrier(); \
 313                 if (COND) { \
 314                         ret = 0; \
 315                         break; \
 316                 } \
 317                 if (now - base >= timeout) { \
 318                         ret = -ETIMEDOUT; \
 319                         break; \
 320                 } \
 321                 cpu_relax(); \
 322                 if (!(ATOMIC)) { \
 323                         preempt_disable(); \
 324                         if (unlikely(cpu != smp_processor_id())) { \
 325                                 timeout -= now - base; \
 326                                 cpu = smp_processor_id(); \
 327                                 base = local_clock(); \
 328                         } \
 329                 } \
 330         } \
 331         ret; \
 332 })
 333
 334 #define wait_for_us(COND, US) \
 335 ({ \
 336         int ret__; \
 337         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 338         if ((US) > 10) \
 339                 ret__ = _wait_for((COND), (US), 10, 10); \
 340         else \
 341                 ret__ = _wait_for_atomic((COND), (US), 0); \
 342         ret__; \
 343 })
 344
 345 #define wait_for_atomic_us(COND, US) \
 346 ({ \
 347         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 348         BUILD_BUG_ON((US) > 50000); \
 349         _wait_for_atomic((COND), (US), 1); \
 350 })
 351
 352 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
 353
 354 #define KHz(x) (1000 * (x))
 355 #define MHz(x) KHz(1000 * (x))
 356
 357 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
 358 static inline void __add_taint_for_CI(unsigned int taint)
 359 {
 360         /*
 361          * The system is "ok", just about surviving for the user, but
 362          * CI results are now unreliable as the HW is very suspect.
 363          * CI checks the taint state after every test and will reboot
 364          * the machine if the kernel is tainted.
 365          */
 366         add_taint(taint, LOCKDEP_STILL_OK);
 367 }
 368
 369 void cancel_timer(struct timer_list *t);
 370 void set_timer_ms(struct timer_list *t, unsigned long timeout);
 371
 372 static inline bool timer_active(const struct timer_list *t)
 373 {
 374         return READ_ONCE(t->expires);
 375 }
 376
 377 static inline bool timer_expired(const struct timer_list *t)
 378 {
 379         return timer_active(t) && !timer_pending(t);
 380 }
 381
 382 static inline bool i915_run_as_guest(void)
 383 {
 384 #if IS_ENABLED(CONFIG_X86)
 385         return !hypervisor_is_type(X86_HYPER_NATIVE);
 386 #else
 387         /* Not supported yet */
 388         return false;
 389 #endif
 390 }
 391
 392 bool i915_vtd_active(struct drm_i915_private *i915);
 393
 394 #endif /* !__I915_UTILS_H */