1 /* $NetBSD: i915_utils.h,v 1.6 2022/05/27 21:02:27 riastradh Exp $ */
2
3 /*
4 * Copyright © 2016 Intel Corporation
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23 * IN THE SOFTWARE.
24 *
25 */
26
27 #ifndef __I915_UTILS_H
28 #define __I915_UTILS_H
29
30 #include <linux/list.h>
31 #include <linux/overflow.h>
32 #include <linux/sched.h>
33 #include <linux/sched/clock.h>
34 #include <linux/types.h>
35 #include <linux/workqueue.h>
36
37 struct drm_i915_private;
38 struct timer_list;
39
40 #undef WARN_ON
41 /* Many gcc seem to no see through this and fall over :( */
42 #if 0
43 #define WARN_ON(x) ({ \
44 bool __i915_warn_cond = (x); \
45 if (__builtin_constant_p(__i915_warn_cond)) \
46 BUILD_BUG_ON(__i915_warn_cond); \
47 WARN(__i915_warn_cond, "WARN_ON(" #x ")\n"); })
48 #else
49 #define WARN_ON(x) WARN((x), "%s\n", "WARN_ON(" __stringify(x) ")")
50 #endif
51
52 #undef WARN_ON_ONCE
53 #define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")\n")
54
55 #define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
56 __stringify(x), (long)(x))
57
58 void __printf(3, 4)
59 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
60 const char *fmt, ...);
61
62 #define i915_report_error(dev_priv, fmt, ...) \
63 __i915_printk(dev_priv, KERN_ERR, fmt, ##__VA_ARGS__)
64
65 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
66
67 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
68 const char *func, int line);
69 #define i915_inject_probe_error(_i915, _err) \
70 __i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
71 bool i915_error_injected(void);
72
73 #else
74
75 #define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
76 #define i915_error_injected() false
77
78 #endif
79
80 #define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
81
82 #define i915_probe_error(i915, fmt, ...) \
83 __i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \
84 fmt, ##__VA_ARGS__)
85
86 #if defined(GCC_VERSION) && GCC_VERSION >= 70000
87 #define add_overflows_t(T, A, B) \
88 __builtin_add_overflow_p((A), (B), (T)0)
89 #else
90 #define add_overflows_t(T, A, B) ({ \
91 typeof(A) a = (A); \
92 typeof(B) b = (B); \
93 (T)(a + b) < a; \
94 })
95 #endif
96
97 #define add_overflows(A, B) \
98 add_overflows_t(typeof((A) + (B)), (A), (B))
99
100 #define range_overflows(start, size, max) ({ \
101 typeof(start) start__ = (start); \
102 typeof(size) size__ = (size); \
103 typeof(max) max__ = (max); \
104 (void)(&start__ == &size__); \
105 (void)(&start__ == &max__); \
106 start__ > max__ || size__ > max__ - start__; \
107 })
108
109 #define range_overflows_t(type, start, size, max) \
110 range_overflows((type)(start), (type)(size), (type)(max))
111
112 /* Note we don't consider signbits :| */
113 #define overflows_type(x, T) \
114 (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))
115
116 static inline bool
__check_struct_size(size_t base,size_t arr,size_t count,size_t * size)117 __check_struct_size(size_t base, size_t arr, size_t count, size_t *size)
118 {
119 size_t sz;
120
121 if (check_mul_overflow(count, arr, &sz))
122 return false;
123
124 if (check_add_overflow(sz, base, &sz))
125 return false;
126
127 *size = sz;
128 return true;
129 }
130
131 /**
132 * check_struct_size() - Calculate size of structure with trailing array.
133 * @p: Pointer to the structure.
134 * @member: Name of the array member.
135 * @n: Number of elements in the array.
136 * @sz: Total size of structure and array
137 *
138 * Calculates size of memory needed for structure @p followed by an
139 * array of @n @member elements, like struct_size() but reports
140 * whether it overflowed, and the resultant size in @sz
141 *
142 * Return: false if the calculation overflowed.
143 */
144 #define check_struct_size(p, member, n, sz) \
145 likely(__check_struct_size(sizeof(*(p)), \
146 sizeof(*(p)->member) + __must_be_array((p)->member), \
147 n, sz))
148
149 #define ptr_mask_bits(ptr, n) ({ \
150 unsigned long __v = (unsigned long)(ptr); \
151 (typeof(ptr))(__v & -BIT(n)); \
152 })
153
154 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
155
156 #define ptr_unpack_bits(ptr, bits, n) ({ \
157 unsigned long __v = (unsigned long)(ptr); \
158 *(bits) = __v & (BIT(n) - 1); \
159 (typeof(ptr))(__v & -BIT(n)); \
160 })
161
162 #define ptr_pack_bits(ptr, bits, n) ({ \
163 unsigned long __bits = (bits); \
164 GEM_BUG_ON(__bits & -BIT(n)); \
165 ((typeof(ptr))((unsigned long)(ptr) | __bits)); \
166 })
167
168 #define ptr_dec(ptr) ({ \
169 unsigned long __v = (unsigned long)(ptr); \
170 (typeof(ptr))(__v - 1); \
171 })
172
173 #define ptr_inc(ptr) ({ \
174 unsigned long __v = (unsigned long)(ptr); \
175 (typeof(ptr))(__v + 1); \
176 })
177
178 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
179 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
180 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
181 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
182
183 #define struct_member(T, member) (((T *)0)->member)
184
185 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
186
187 #define fetch_and_zero(ptr) ({ \
188 typeof(*ptr) __T = *(ptr); \
189 *(ptr) = (typeof(*ptr))0; \
190 __T; \
191 })
192
193 /*
194 * container_of_user: Extract the superclass from a pointer to a member.
195 *
196 * Exactly like container_of() with the exception that it plays nicely
197 * with sparse for __user @ptr.
198 */
199 #define container_of_user(ptr, type, member) ({ \
200 void __user *__mptr = (void __user *)(ptr); \
201 BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
202 !__same_type(*(ptr), void), \
203 "pointer type mismatch in container_of()"); \
204 ((type __user *)(__mptr - offsetof(type, member))); })
205
206 /*
207 * check_user_mbz: Check that a user value exists and is zero
208 *
209 * Frequently in our uABI we reserve space for future extensions, and
210 * two ensure that userspace is prepared we enforce that space must
211 * be zero. (Then any future extension can safely assume a default value
212 * of 0.)
213 *
214 * check_user_mbz() combines checking that the user pointer is accessible
215 * and that the contained value is zero.
216 *
217 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
218 */
219 #define check_user_mbz(U) ({ \
220 typeof(*(U)) mbz__; \
221 get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0; \
222 })
223
ptr_to_u64(const void * ptr)224 static inline u64 ptr_to_u64(const void *ptr)
225 {
226 return (uintptr_t)ptr;
227 }
228
229 #define u64_to_ptr(T, x) ({ \
230 typecheck(u64, x); \
231 (T *)(uintptr_t)(x); \
232 })
233
234 #define __mask_next_bit(mask) ({ \
235 int __idx = ffs(mask) - 1; \
236 mask &= ~BIT(__idx); \
237 __idx; \
238 })
239
__list_del_many(struct list_head * head,struct list_head * first)240 static inline void __list_del_many(struct list_head *head,
241 struct list_head *first)
242 {
243 first->prev = head;
244 WRITE_ONCE(head->next, first);
245 }
246
247 /*
248 * Wait until the work is finally complete, even if it tries to postpone
249 * by requeueing itself. Note, that if the worker never cancels itself,
250 * we will spin forever.
251 */
drain_delayed_work(struct delayed_work * dw)252 static inline void drain_delayed_work(struct delayed_work *dw)
253 {
254 do {
255 while (flush_delayed_work(dw))
256 ;
257 } while (delayed_work_pending(dw));
258 }
259
msecs_to_jiffies_timeout(const unsigned int m)260 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
261 {
262 unsigned long j = msecs_to_jiffies(m);
263
264 return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
265 }
266
267 /*
268 * If you need to wait X milliseconds between events A and B, but event B
269 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
270 * when event A happened, then just before event B you call this function and
271 * pass the timestamp as the first argument, and X as the second argument.
272 */
273 static inline void
wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies,int to_wait_ms)274 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
275 {
276 unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
277
278 /*
279 * Don't re-read the value of "jiffies" every time since it may change
280 * behind our back and break the math.
281 */
282 tmp_jiffies = jiffies;
283 target_jiffies = timestamp_jiffies +
284 msecs_to_jiffies_timeout(to_wait_ms);
285
286 if (time_after(target_jiffies, tmp_jiffies)) {
287 remaining_jiffies = target_jiffies - tmp_jiffies;
288 while (remaining_jiffies)
289 remaining_jiffies =
290 schedule_timeout_uninterruptible(remaining_jiffies);
291 }
292 }
293
294 /**
295 * __wait_for - magic wait macro
296 *
297 * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
298 * important that we check the condition again after having timed out, since the
299 * timeout could be due to preemption or similar and we've never had a chance to
300 * check the condition before the timeout.
301 */
302 #ifdef __NetBSD__
303 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
304 int ret__ = 0; \
305 if (cold) { \
306 int ms__ = ((US) + 999)/1000; \
307 for (;;) { \
308 const bool expired__ = ms__-- == 0; \
309 OP; \
310 barrier(); \
311 if (COND) { \
312 ret__ = 0; \
313 break; \
314 } \
315 if (expired__) { \
316 ret__ = -ETIMEDOUT; \
317 break; \
318 } \
319 DELAY(1000); \
320 } \
321 } else { \
322 const ktime_t end__ = \
323 ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
324 long wait__ = (Wmin); \
325 might_sleep(); \
326 for (;;) { \
327 const bool expired__ = \
328 ktime_after(ktime_get_raw(), end__); \
329 OP; \
330 /* Guarantee COND check prior to timeout */ \
331 barrier(); \
332 if (COND) { \
333 ret__ = 0; \
334 break; \
335 } \
336 if (expired__) { \
337 ret__ = -ETIMEDOUT; \
338 break; \
339 } \
340 usleep_range(wait__, wait__ * 2); \
341 if (wait__ < (Wmax)) \
342 wait__ <<= 1; \
343 } \
344 } \
345 ret__; \
346 })
347 #else /* !NetBSD */
348 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
349 const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
350 long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
351 int ret__; \
352 might_sleep(); \
353 for (;;) { \
354 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
355 OP; \
356 /* Guarantee COND check prior to timeout */ \
357 barrier(); \
358 if (COND) { \
359 ret__ = 0; \
360 break; \
361 } \
362 if (expired__) { \
363 ret__ = -ETIMEDOUT; \
364 break; \
365 } \
366 usleep_range(wait__, wait__ * 2); \
367 if (wait__ < (Wmax)) \
368 wait__ <<= 1; \
369 } \
370 ret__; \
371 })
372 #endif
373
374 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
375 (Wmax))
376 #define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000)
377
378 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
379 #if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
380 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
381 #else
382 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
383 #endif
384
385 #define _wait_for_atomic(COND, US, ATOMIC) \
386 ({ \
387 int cpu, ret, timeout = (US) * 1000; \
388 u64 base; \
389 _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
390 if (!(ATOMIC)) { \
391 preempt_disable(); \
392 cpu = smp_processor_id(); \
393 } \
394 base = local_clock(); \
395 for (;;) { \
396 u64 now = local_clock(); \
397 if (!(ATOMIC)) \
398 preempt_enable(); \
399 /* Guarantee COND check prior to timeout */ \
400 barrier(); \
401 if (COND) { \
402 ret = 0; \
403 break; \
404 } \
405 if (now - base >= timeout) { \
406 ret = -ETIMEDOUT; \
407 break; \
408 } \
409 cpu_relax(); \
410 if (!(ATOMIC)) { \
411 preempt_disable(); \
412 if (unlikely(cpu != smp_processor_id())) { \
413 timeout -= now - base; \
414 cpu = smp_processor_id(); \
415 base = local_clock(); \
416 } \
417 } \
418 } \
419 ret; \
420 })
421
422 #define wait_for_us(COND, US) \
423 ({ \
424 int ret__; \
425 BUILD_BUG_ON(!__builtin_constant_p(US)); \
426 if ((US) > 10) \
427 ret__ = _wait_for((COND), (US), 10, 10); \
428 else \
429 ret__ = _wait_for_atomic((COND), (US), 0); \
430 ret__; \
431 })
432
433 #define wait_for_atomic_us(COND, US) \
434 ({ \
435 BUILD_BUG_ON(!__builtin_constant_p(US)); \
436 BUILD_BUG_ON((US) > 50000); \
437 _wait_for_atomic((COND), (US), 1); \
438 })
439
440 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
441
442 #define KHz(x) (1000 * (x))
443 #define MHz(x) KHz(1000 * (x))
444
445 #define KBps(x) (1000 * (x))
446 #define MBps(x) KBps(1000 * (x))
447 #define GBps(x) ((u64)1000 * MBps((x)))
448
yesno(bool v)449 static inline const char *yesno(bool v)
450 {
451 return v ? "yes" : "no";
452 }
453
onoff(bool v)454 static inline const char *onoff(bool v)
455 {
456 return v ? "on" : "off";
457 }
458
enableddisabled(bool v)459 static inline const char *enableddisabled(bool v)
460 {
461 return v ? "enabled" : "disabled";
462 }
463
add_taint_for_CI(unsigned int taint)464 static inline void add_taint_for_CI(unsigned int taint)
465 {
466 /*
467 * The system is "ok", just about surviving for the user, but
468 * CI results are now unreliable as the HW is very suspect.
469 * CI checks the taint state after every test and will reboot
470 * the machine if the kernel is tainted.
471 */
472 add_taint(taint, LOCKDEP_STILL_OK);
473 }
474
475 void cancel_timer(struct timer_list *t);
476 void set_timer_ms(struct timer_list *t, unsigned long timeout);
477
478 #ifdef __NetBSD__
479 static inline bool
timer_expired(const struct timer_list * t)480 timer_expired(const struct timer_list *t)
481 {
482 return callout_expired(__UNCONST(&t->tl_callout));
483 }
484 #else
timer_expired(const struct timer_list * t)485 static inline bool timer_expired(const struct timer_list *t)
486 {
487 return READ_ONCE(t->expires) && !timer_pending(t);
488 }
489 #endif
490
491 /*
492 * This is a lookalike for IS_ENABLED() that takes a kconfig value,
493 * e.g. CONFIG_DRM_I915_SPIN_REQUEST, and evaluates whether it is non-zero
494 * i.e. whether the configuration is active. Wrapping up the config inside
495 * a boolean context prevents clang and smatch from complaining about potential
496 * issues in confusing logical-&& with bitwise-& for constants.
497 *
498 * Sadly IS_ENABLED() itself does not work with kconfig values.
499 *
500 * Returns 0 if @config is 0, 1 if set to any value.
501 */
502 #define IS_ACTIVE(config) ((config) != 0)
503
504 #endif /* !__I915_UTILS_H */
505