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 #define ptr_mask_bits(ptr, n) ({                                        \
 119         unsigned long __v = (unsigned long)(ptr);                       \
 120         (typeof(ptr))(__v & -BIT(n));                                   \
 121 })
 122
 123 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
 124
 125 #define ptr_unpack_bits(ptr, bits, n) ({                                \
 126         unsigned long __v = (unsigned long)(ptr);                       \
 127         *(bits) = __v & (BIT(n) - 1);                                   \
 128         (typeof(ptr))(__v & -BIT(n));                                   \
 129 })
 130
 131 #define ptr_pack_bits(ptr, bits, n) ({                                  \
 132         unsigned long __bits = (bits);                                  \
 133         GEM_BUG_ON(__bits & -BIT(n));                                   \
 134         ((typeof(ptr))((unsigned long)(ptr) | __bits));                 \
 135 })
 136
 137 #define ptr_dec(ptr) ({                                                 \
 138         unsigned long __v = (unsigned long)(ptr);                       \
 139         (typeof(ptr))(__v - 1);                                         \
 140 })
 141
 142 #define ptr_inc(ptr) ({                                                 \
 143         unsigned long __v = (unsigned long)(ptr);                       \
 144         (typeof(ptr))(__v + 1);                                         \
 145 })
 146
 147 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
 148 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
 149 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
 150 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
 151
 152 #define struct_member(T, member) (((T *)0)->member)
 153
 154 #define fetch_and_zero(ptr) ({                                          \
 155         typeof(*ptr) __T = *(ptr);                                      \
 156         *(ptr) = (typeof(*ptr))0;                                       \
 157         __T;                                                            \
 158 })
 159
 160 static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
 161 {
 162         return a - b;
 163 }
 164
 165 /*
 166  * container_of_user: Extract the superclass from a pointer to a member.
 167  *
 168  * Exactly like container_of() with the exception that it plays nicely
 169  * with sparse for __user @ptr.
 170  */
 171 #define container_of_user(ptr, type, member) ({                         \
 172         void __user *__mptr = (void __user *)(ptr);                     \
 173         BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
 174                          !__same_type(*(ptr), void),                    \
 175                          "pointer type mismatch in container_of()");    \
 176         ((type __user *)(__mptr - offsetof(type, member))); })
 177
 178 /*
 179  * check_user_mbz: Check that a user value exists and is zero
 180  *
 181  * Frequently in our uABI we reserve space for future extensions, and
 182  * two ensure that userspace is prepared we enforce that space must
 183  * be zero. (Then any future extension can safely assume a default value
 184  * of 0.)
 185  *
 186  * check_user_mbz() combines checking that the user pointer is accessible
 187  * and that the contained value is zero.
 188  *
 189  * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
 190  */
 191 #define check_user_mbz(U) ({                                            \
 192         typeof(*(U)) mbz__;                                             \
 193         get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;           \
 194 })
 195
 196 #define u64_to_ptr(T, x) ({                                             \
 197         typecheck(u64, x);                                              \
 198         (T *)(uintptr_t)(x);                                            \
 199 })
 200
 201 #define __mask_next_bit(mask) ({                                        \
 202         int __idx = ffs(mask) - 1;                                      \
 203         mask &= ~BIT(__idx);                                            \
 204         __idx;                                                          \
 205 })
 206
 207 static inline bool is_power_of_2_u64(u64 n)
 208 {
 209         return (n != 0 && ((n & (n - 1)) == 0));
 210 }
 211
 212 static inline void __list_del_many(struct list_head *head,
 213                                    struct list_head *first)
 214 {
 215         first->prev = head;
 216         WRITE_ONCE(head->next, first);
 217 }
 218
 219 static inline int list_is_last_rcu(const struct list_head *list,
 220                                    const struct list_head *head)
 221 {
 222         return READ_ONCE(list->next) == head;
 223 }
 224
 225 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
 226 {
 227         unsigned long j = msecs_to_jiffies(m);
 228
 229         return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
 230 }
 231
 232 /*
 233  * If you need to wait X milliseconds between events A and B, but event B
 234  * doesn't happen exactly after event A, you record the timestamp (jiffies) of
 235  * when event A happened, then just before event B you call this function and
 236  * pass the timestamp as the first argument, and X as the second argument.
 237  */
 238 static inline void
 239 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 240 {
 241         unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
 242
 243         /*
 244          * Don't re-read the value of "jiffies" every time since it may change
 245          * behind our back and break the math.
 246          */
 247         tmp_jiffies = jiffies;
 248         target_jiffies = timestamp_jiffies +
 249                          msecs_to_jiffies_timeout(to_wait_ms);
 250
 251         if (time_after(target_jiffies, tmp_jiffies)) {
 252                 remaining_jiffies = target_jiffies - tmp_jiffies;
 253                 while (remaining_jiffies)
 254                         remaining_jiffies =
 255                             schedule_timeout_uninterruptible(remaining_jiffies);
 256         }
 257 }
 258
 259 /**
 260  * __wait_for - magic wait macro
 261  *
 262  * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
 263  * important that we check the condition again after having timed out, since the
 264  * timeout could be due to preemption or similar and we've never had a chance to
 265  * check the condition before the timeout.
 266  */
 267 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
 268         const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
 269         long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
 270         int ret__;                                                      \
 271         might_sleep();                                                  \
 272         for (;;) {                                                      \
 273                 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
 274                 OP;                                                     \
 275                 /* Guarantee COND check prior to timeout */             \
 276                 barrier();                                              \
 277                 if (COND) {                                             \
 278                         ret__ = 0;                                      \
 279                         break;                                          \
 280                 }                                                       \
 281                 if (expired__) {                                        \
 282                         ret__ = -ETIMEDOUT;                             \
 283                         break;                                          \
 284                 }                                                       \
 285                 usleep_range(wait__, wait__ * 2);                       \
 286                 if (wait__ < (Wmax))                                    \
 287                         wait__ <<= 1;                                   \
 288         }                                                               \
 289         ret__;                                                          \
 290 })
 291
 292 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
 293                                                    (Wmax))
 294 #define wait_for(COND, MS)              _wait_for((COND), (MS) * 1000, 10, 1000)
 295
 296 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
 297 #if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
 298 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
 299 #else
 300 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
 301 #endif
 302
 303 #define _wait_for_atomic(COND, US, ATOMIC) \
 304 ({ \
 305         int cpu, ret, timeout = (US) * 1000; \
 306         u64 base; \
 307         _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
 308         if (!(ATOMIC)) { \
 309                 preempt_disable(); \
 310                 cpu = smp_processor_id(); \
 311         } \
 312         base = local_clock(); \
 313         for (;;) { \
 314                 u64 now = local_clock(); \
 315                 if (!(ATOMIC)) \
 316                         preempt_enable(); \
 317                 /* Guarantee COND check prior to timeout */ \
 318                 barrier(); \
 319                 if (COND) { \
 320                         ret = 0; \
 321                         break; \
 322                 } \
 323                 if (now - base >= timeout) { \
 324                         ret = -ETIMEDOUT; \
 325                         break; \
 326                 } \
 327                 cpu_relax(); \
 328                 if (!(ATOMIC)) { \
 329                         preempt_disable(); \
 330                         if (unlikely(cpu != smp_processor_id())) { \
 331                                 timeout -= now - base; \
 332                                 cpu = smp_processor_id(); \
 333                                 base = local_clock(); \
 334                         } \
 335                 } \
 336         } \
 337         ret; \
 338 })
 339
 340 #define wait_for_us(COND, US) \
 341 ({ \
 342         int ret__; \
 343         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 344         if ((US) > 10) \
 345                 ret__ = _wait_for((COND), (US), 10, 10); \
 346         else \
 347                 ret__ = _wait_for_atomic((COND), (US), 0); \
 348         ret__; \
 349 })
 350
 351 #define wait_for_atomic_us(COND, US) \
 352 ({ \
 353         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 354         BUILD_BUG_ON((US) > 50000); \
 355         _wait_for_atomic((COND), (US), 1); \
 356 })
 357
 358 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
 359
 360 #define KHz(x) (1000 * (x))
 361 #define MHz(x) KHz(1000 * (x))
 362
 363 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
 364 static inline void __add_taint_for_CI(unsigned int taint)
 365 {
 366         /*
 367          * The system is "ok", just about surviving for the user, but
 368          * CI results are now unreliable as the HW is very suspect.
 369          * CI checks the taint state after every test and will reboot
 370          * the machine if the kernel is tainted.
 371          */
 372         add_taint(taint, LOCKDEP_STILL_OK);
 373 }
 374
 375 void cancel_timer(struct timer_list *t);
 376 void set_timer_ms(struct timer_list *t, unsigned long timeout);
 377
 378 static inline bool timer_active(const struct timer_list *t)
 379 {
 380         return READ_ONCE(t->expires);
 381 }
 382
 383 static inline bool timer_expired(const struct timer_list *t)
 384 {
 385         return timer_active(t) && !timer_pending(t);
 386 }
 387
 388 static inline bool i915_run_as_guest(void)
 389 {
 390 #if IS_ENABLED(CONFIG_X86)
 391         return !hypervisor_is_type(X86_HYPER_NATIVE);
 392 #else
 393         /* Not supported yet */
 394         return false;
 395 #endif
 396 }
 397
 398 bool i915_vtd_active(struct drm_i915_private *i915);
 399
 400 #endif /* !__I915_UTILS_H */