root/drivers/gpu/drm/i915/i915_utils.h

INCLUDED FROM

DEFINITIONS

1. __check_struct_size
2. ptr_to_u64
3. is_power_of_2_u64
4. __list_del_many
5. drain_delayed_work
6. msecs_to_jiffies_timeout
7. wait_remaining_ms_from_jiffies
8. yesno
9. onoff
10. enableddisabled
11. add_taint_for_CI

   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/types.h>
  32 #include <linux/workqueue.h>
  33 
  34 struct drm_i915_private;
  35 
  36 #undef WARN_ON
  37 /* Many gcc seem to no see through this and fall over :( */
  38 #if 0
  39 #define WARN_ON(x) ({ \
  40         bool __i915_warn_cond = (x); \
  41         if (__builtin_constant_p(__i915_warn_cond)) \
  42                 BUILD_BUG_ON(__i915_warn_cond); \
  43         WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
  44 #else
  45 #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
  46 #endif
  47 
  48 #undef WARN_ON_ONCE
  49 #define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")")
  50 
  51 #define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
  52                              __stringify(x), (long)(x))
  53 
  54 void __printf(3, 4)
  55 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
  56               const char *fmt, ...);
  57 
  58 #define i915_report_error(dev_priv, fmt, ...)                              \
  59         __i915_printk(dev_priv, KERN_ERR, fmt, ##__VA_ARGS__)
  60 
  61 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
  62 
  63 int __i915_inject_load_error(struct drm_i915_private *i915, int err,
  64                              const char *func, int line);
  65 #define i915_inject_load_error(_i915, _err) \
  66         __i915_inject_load_error((_i915), (_err), __func__, __LINE__)
  67 bool i915_error_injected(void);
  68 
  69 #else
  70 
  71 #define i915_inject_load_error(_i915, _err) 0
  72 #define i915_error_injected() false
  73 
  74 #endif
  75 
  76 #define i915_inject_probe_failure(i915) i915_inject_load_error((i915), -ENODEV)
  77 
  78 #define i915_probe_error(i915, fmt, ...)                                   \
  79         __i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \
  80                       fmt, ##__VA_ARGS__)
  81 
  82 #if defined(GCC_VERSION) && GCC_VERSION >= 70000
  83 #define add_overflows_t(T, A, B) \
  84         __builtin_add_overflow_p((A), (B), (T)0)
  85 #else
  86 #define add_overflows_t(T, A, B) ({ \
  87         typeof(A) a = (A); \
  88         typeof(B) b = (B); \
  89         (T)(a + b) < a; \
  90 })
  91 #endif
  92 
  93 #define add_overflows(A, B) \
  94         add_overflows_t(typeof((A) + (B)), (A), (B))
  95 
  96 #define range_overflows(start, size, max) ({ \
  97         typeof(start) start__ = (start); \
  98         typeof(size) size__ = (size); \
  99         typeof(max) max__ = (max); \
 100         (void)(&start__ == &size__); \
 101         (void)(&start__ == &max__); \
 102         start__ > max__ || size__ > max__ - start__; \
 103 })
 104 
 105 #define range_overflows_t(type, start, size, max) \
 106         range_overflows((type)(start), (type)(size), (type)(max))
 107 
 108 /* Note we don't consider signbits :| */
 109 #define overflows_type(x, T) \
 110         (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))
 111 
 112 static inline bool
 113 __check_struct_size(size_t base, size_t arr, size_t count, size_t *size)
 114 {
 115         size_t sz;
 116 
 117         if (check_mul_overflow(count, arr, &sz))
 118                 return false;
 119 
 120         if (check_add_overflow(sz, base, &sz))
 121                 return false;
 122 
 123         *size = sz;
 124         return true;
 125 }
 126 
 127 /**
 128  * check_struct_size() - Calculate size of structure with trailing array.
 129  * @p: Pointer to the structure.
 130  * @member: Name of the array member.
 131  * @n: Number of elements in the array.
 132  * @sz: Total size of structure and array
 133  *
 134  * Calculates size of memory needed for structure @p followed by an
 135  * array of @n @member elements, like struct_size() but reports
 136  * whether it overflowed, and the resultant size in @sz
 137  *
 138  * Return: false if the calculation overflowed.
 139  */
 140 #define check_struct_size(p, member, n, sz) \
 141         likely(__check_struct_size(sizeof(*(p)), \
 142                                    sizeof(*(p)->member) + __must_be_array((p)->member), \
 143                                    n, sz))
 144 
 145 #define ptr_mask_bits(ptr, n) ({                                        \
 146         unsigned long __v = (unsigned long)(ptr);                       \
 147         (typeof(ptr))(__v & -BIT(n));                                   \
 148 })
 149 
 150 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
 151 
 152 #define ptr_unpack_bits(ptr, bits, n) ({                                \
 153         unsigned long __v = (unsigned long)(ptr);                       \
 154         *(bits) = __v & (BIT(n) - 1);                                   \
 155         (typeof(ptr))(__v & -BIT(n));                                   \
 156 })
 157 
 158 #define ptr_pack_bits(ptr, bits, n) ({                                  \
 159         unsigned long __bits = (bits);                                  \
 160         GEM_BUG_ON(__bits & -BIT(n));                                   \
 161         ((typeof(ptr))((unsigned long)(ptr) | __bits));                 \
 162 })
 163 
 164 #define ptr_dec(ptr) ({                                                 \
 165         unsigned long __v = (unsigned long)(ptr);                       \
 166         (typeof(ptr))(__v - 1);                                         \
 167 })
 168 
 169 #define ptr_inc(ptr) ({                                                 \
 170         unsigned long __v = (unsigned long)(ptr);                       \
 171         (typeof(ptr))(__v + 1);                                         \
 172 })
 173 
 174 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
 175 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
 176 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
 177 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
 178 
 179 #define struct_member(T, member) (((T *)0)->member)
 180 
 181 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
 182 
 183 #define fetch_and_zero(ptr) ({                                          \
 184         typeof(*ptr) __T = *(ptr);                                      \
 185         *(ptr) = (typeof(*ptr))0;                                       \
 186         __T;                                                            \
 187 })
 188 
 189 /*
 190  * container_of_user: Extract the superclass from a pointer to a member.
 191  *
 192  * Exactly like container_of() with the exception that it plays nicely
 193  * with sparse for __user @ptr.
 194  */
 195 #define container_of_user(ptr, type, member) ({                         \
 196         void __user *__mptr = (void __user *)(ptr);                     \
 197         BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
 198                          !__same_type(*(ptr), void),                    \
 199                          "pointer type mismatch in container_of()");    \
 200         ((type __user *)(__mptr - offsetof(type, member))); })
 201 
 202 /*
 203  * check_user_mbz: Check that a user value exists and is zero
 204  *
 205  * Frequently in our uABI we reserve space for future extensions, and
 206  * two ensure that userspace is prepared we enforce that space must
 207  * be zero. (Then any future extension can safely assume a default value
 208  * of 0.)
 209  *
 210  * check_user_mbz() combines checking that the user pointer is accessible
 211  * and that the contained value is zero.
 212  *
 213  * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
 214  */
 215 #define check_user_mbz(U) ({                                            \
 216         typeof(*(U)) mbz__;                                             \
 217         get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;           \
 218 })
 219 
 220 static inline u64 ptr_to_u64(const void *ptr)
 221 {
 222         return (uintptr_t)ptr;
 223 }
 224 
 225 #define u64_to_ptr(T, x) ({                                             \
 226         typecheck(u64, x);                                              \
 227         (T *)(uintptr_t)(x);                                            \
 228 })
 229 
 230 #define __mask_next_bit(mask) ({                                        \
 231         int __idx = ffs(mask) - 1;                                      \
 232         mask &= ~BIT(__idx);                                            \
 233         __idx;                                                          \
 234 })
 235 
 236 static inline bool is_power_of_2_u64(u64 n)
 237 {
 238         return (n != 0 && ((n & (n - 1)) == 0));
 239 }
 240 
 241 static inline void __list_del_many(struct list_head *head,
 242                                    struct list_head *first)
 243 {
 244         first->prev = head;
 245         WRITE_ONCE(head->next, first);
 246 }
 247 
 248 /*
 249  * Wait until the work is finally complete, even if it tries to postpone
 250  * by requeueing itself. Note, that if the worker never cancels itself,
 251  * we will spin forever.
 252  */
 253 static inline void drain_delayed_work(struct delayed_work *dw)
 254 {
 255         do {
 256                 while (flush_delayed_work(dw))
 257                         ;
 258         } while (delayed_work_pending(dw));
 259 }
 260 
 261 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
 262 {
 263         unsigned long j = msecs_to_jiffies(m);
 264 
 265         return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
 266 }
 267 
 268 /*
 269  * If you need to wait X milliseconds between events A and B, but event B
 270  * doesn't happen exactly after event A, you record the timestamp (jiffies) of
 271  * when event A happened, then just before event B you call this function and
 272  * pass the timestamp as the first argument, and X as the second argument.
 273  */
 274 static inline void
 275 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 276 {
 277         unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
 278 
 279         /*
 280          * Don't re-read the value of "jiffies" every time since it may change
 281          * behind our back and break the math.
 282          */
 283         tmp_jiffies = jiffies;
 284         target_jiffies = timestamp_jiffies +
 285                          msecs_to_jiffies_timeout(to_wait_ms);
 286 
 287         if (time_after(target_jiffies, tmp_jiffies)) {
 288                 remaining_jiffies = target_jiffies - tmp_jiffies;
 289                 while (remaining_jiffies)
 290                         remaining_jiffies =
 291                             schedule_timeout_uninterruptible(remaining_jiffies);
 292         }
 293 }
 294 
 295 /**
 296  * __wait_for - magic wait macro
 297  *
 298  * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
 299  * important that we check the condition again after having timed out, since the
 300  * timeout could be due to preemption or similar and we've never had a chance to
 301  * check the condition before the timeout.
 302  */
 303 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
 304         const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
 305         long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
 306         int ret__;                                                      \
 307         might_sleep();                                                  \
 308         for (;;) {                                                      \
 309                 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
 310                 OP;                                                     \
 311                 /* Guarantee COND check prior to timeout */             \
 312                 barrier();                                              \
 313                 if (COND) {                                             \
 314                         ret__ = 0;                                      \
 315                         break;                                          \
 316                 }                                                       \
 317                 if (expired__) {                                        \
 318                         ret__ = -ETIMEDOUT;                             \
 319                         break;                                          \
 320                 }                                                       \
 321                 usleep_range(wait__, wait__ * 2);                       \
 322                 if (wait__ < (Wmax))                                    \
 323                         wait__ <<= 1;                                   \
 324         }                                                               \
 325         ret__;                                                          \
 326 })
 327 
 328 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
 329                                                    (Wmax))
 330 #define wait_for(COND, MS)              _wait_for((COND), (MS) * 1000, 10, 1000)
 331 
 332 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
 333 #if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
 334 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
 335 #else
 336 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
 337 #endif
 338 
 339 #define _wait_for_atomic(COND, US, ATOMIC) \
 340 ({ \
 341         int cpu, ret, timeout = (US) * 1000; \
 342         u64 base; \
 343         _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
 344         if (!(ATOMIC)) { \
 345                 preempt_disable(); \
 346                 cpu = smp_processor_id(); \
 347         } \
 348         base = local_clock(); \
 349         for (;;) { \
 350                 u64 now = local_clock(); \
 351                 if (!(ATOMIC)) \
 352                         preempt_enable(); \
 353                 /* Guarantee COND check prior to timeout */ \
 354                 barrier(); \
 355                 if (COND) { \
 356                         ret = 0; \
 357                         break; \
 358                 } \
 359                 if (now - base >= timeout) { \
 360                         ret = -ETIMEDOUT; \
 361                         break; \
 362                 } \
 363                 cpu_relax(); \
 364                 if (!(ATOMIC)) { \
 365                         preempt_disable(); \
 366                         if (unlikely(cpu != smp_processor_id())) { \
 367                                 timeout -= now - base; \
 368                                 cpu = smp_processor_id(); \
 369                                 base = local_clock(); \
 370                         } \
 371                 } \
 372         } \
 373         ret; \
 374 })
 375 
 376 #define wait_for_us(COND, US) \
 377 ({ \
 378         int ret__; \
 379         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 380         if ((US) > 10) \
 381                 ret__ = _wait_for((COND), (US), 10, 10); \
 382         else \
 383                 ret__ = _wait_for_atomic((COND), (US), 0); \
 384         ret__; \
 385 })
 386 
 387 #define wait_for_atomic_us(COND, US) \
 388 ({ \
 389         BUILD_BUG_ON(!__builtin_constant_p(US)); \
 390         BUILD_BUG_ON((US) > 50000); \
 391         _wait_for_atomic((COND), (US), 1); \
 392 })
 393 
 394 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
 395 
 396 #define KHz(x) (1000 * (x))
 397 #define MHz(x) KHz(1000 * (x))
 398 
 399 #define KBps(x) (1000 * (x))
 400 #define MBps(x) KBps(1000 * (x))
 401 #define GBps(x) ((u64)1000 * MBps((x)))
 402 
 403 static inline const char *yesno(bool v)
 404 {
 405         return v ? "yes" : "no";
 406 }
 407 
 408 static inline const char *onoff(bool v)
 409 {
 410         return v ? "on" : "off";
 411 }
 412 
 413 static inline const char *enableddisabled(bool v)
 414 {
 415         return v ? "enabled" : "disabled";
 416 }
 417 
 418 static inline void add_taint_for_CI(unsigned int taint)
 419 {
 420         /*
 421          * The system is "ok", just about surviving for the user, but
 422          * CI results are now unreliable as the HW is very suspect.
 423          * CI checks the taint state after every test and will reboot
 424          * the machine if the kernel is tainted.
 425          */
 426         add_taint(taint, LOCKDEP_STILL_OK);
 427 }
 428 
 429 #endif /* !__I915_UTILS_H */