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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
34struct drm_i915_private;
35struct timer_list;
36
37#define FDO_BUG_URL "https://gitlab.freedesktop.org/drm/intel/-/wikis/How-to-file-i915-bugs"
38
39#undef WARN_ON
40/* Many gcc seem to no see through this and fall over :( */
41#if 0
42#define WARN_ON(x) ({ \
43 bool __i915_warn_cond = (x); \
44 if (__builtin_constant_p(__i915_warn_cond)) \
45 BUILD_BUG_ON(__i915_warn_cond); \
46 WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
47#else
48#define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
49#endif
50
51#undef WARN_ON_ONCE
52#define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")")
53
54#define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
55 __stringify(x), (long)(x))
56
57void __printf(3, 4)
58__i915_printk(struct drm_i915_private *dev_priv, const char *level,
59 const char *fmt, ...);
60
61#define i915_report_error(dev_priv, fmt, ...) \
62 __i915_printk(dev_priv, KERN_ERR, fmt, ##__VA_ARGS__)
63
64#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
65
66int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
67 const char *func, int line);
68#define i915_inject_probe_error(_i915, _err) \
69 __i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
70bool i915_error_injected(void);
71
72#else
73
74#define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
75#define i915_error_injected() false
76
77#endif
78
79#define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
80
81#define i915_probe_error(i915, fmt, ...) \
82 __i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \
83 fmt, ##__VA_ARGS__)
84
85#if defined(GCC_VERSION) && GCC_VERSION >= 70000
86#define add_overflows_t(T, A, B) \
87 __builtin_add_overflow_p((A), (B), (T)0)
88#else
89#define add_overflows_t(T, A, B) ({ \
90 typeof(A) a = (A); \
91 typeof(B) b = (B); \
92 (T)(a + b) < a; \
93})
94#endif
95
96#define add_overflows(A, B) \
97 add_overflows_t(typeof((A) + (B)), (A), (B))
98
99#define range_overflows(start, size, max) ({ \
100 typeof(start) start__ = (start); \
101 typeof(size) size__ = (size); \
102 typeof(max) max__ = (max); \
103 (void)(&start__ == &size__); \
104 (void)(&start__ == &max__); \
105 start__ >= max__ || size__ > max__ - start__; \
106})
107
108#define range_overflows_t(type, start, size, max) \
109 range_overflows((type)(start), (type)(size), (type)(max))
110
111#define range_overflows_end(start, size, max) ({ \
112 typeof(start) start__ = (start); \
113 typeof(size) size__ = (size); \
114 typeof(max) max__ = (max); \
115 (void)(&start__ == &size__); \
116 (void)(&start__ == &max__); \
117 start__ > max__ || size__ > max__ - start__; \
118})
119
120#define range_overflows_end_t(type, start, size, max) \
121 range_overflows_end((type)(start), (type)(size), (type)(max))
122
123/* Note we don't consider signbits :| */
124#define overflows_type(x, T) \
125 (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))
126
127static inline bool
128__check_struct_size(size_t base, size_t arr, size_t count, size_t *size)
129{
130 size_t sz;
131
132 if (check_mul_overflow(count, arr, &sz))
133 return false;
134
135 if (check_add_overflow(sz, base, &sz))
136 return false;
137
138 *size = sz;
139 return true;
140}
141
142/**
143 * check_struct_size() - Calculate size of structure with trailing array.
144 * @p: Pointer to the structure.
145 * @member: Name of the array member.
146 * @n: Number of elements in the array.
147 * @sz: Total size of structure and array
148 *
149 * Calculates size of memory needed for structure @p followed by an
150 * array of @n @member elements, like struct_size() but reports
151 * whether it overflowed, and the resultant size in @sz
152 *
153 * Return: false if the calculation overflowed.
154 */
155#define check_struct_size(p, member, n, sz) \
156 likely(__check_struct_size(sizeof(*(p)), \
157 sizeof(*(p)->member) + __must_be_array((p)->member), \
158 n, sz))
159
160#define ptr_mask_bits(ptr, n) ({ \
161 unsigned long __v = (unsigned long)(ptr); \
162 (typeof(ptr))(__v & -BIT(n)); \
163})
164
165#define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
166
167#define ptr_unpack_bits(ptr, bits, n) ({ \
168 unsigned long __v = (unsigned long)(ptr); \
169 *(bits) = __v & (BIT(n) - 1); \
170 (typeof(ptr))(__v & -BIT(n)); \
171})
172
173#define ptr_pack_bits(ptr, bits, n) ({ \
174 unsigned long __bits = (bits); \
175 GEM_BUG_ON(__bits & -BIT(n)); \
176 ((typeof(ptr))((unsigned long)(ptr) | __bits)); \
177})
178
179#define ptr_dec(ptr) ({ \
180 unsigned long __v = (unsigned long)(ptr); \
181 (typeof(ptr))(__v - 1); \
182})
183
184#define ptr_inc(ptr) ({ \
185 unsigned long __v = (unsigned long)(ptr); \
186 (typeof(ptr))(__v + 1); \
187})
188
189#define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
190#define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
191#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
192#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
193
194#define struct_member(T, member) (((T *)0)->member)
195
196#define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
197
198#define fetch_and_zero(ptr) ({ \
199 typeof(*ptr) __T = *(ptr); \
200 *(ptr) = (typeof(*ptr))0; \
201 __T; \
202})
203
204/*
205 * container_of_user: Extract the superclass from a pointer to a member.
206 *
207 * Exactly like container_of() with the exception that it plays nicely
208 * with sparse for __user @ptr.
209 */
210#define container_of_user(ptr, type, member) ({ \
211 void __user *__mptr = (void __user *)(ptr); \
212 BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
213 !__same_type(*(ptr), void), \
214 "pointer type mismatch in container_of()"); \
215 ((type __user *)(__mptr - offsetof(type, member))); })
216
217/*
218 * check_user_mbz: Check that a user value exists and is zero
219 *
220 * Frequently in our uABI we reserve space for future extensions, and
221 * two ensure that userspace is prepared we enforce that space must
222 * be zero. (Then any future extension can safely assume a default value
223 * of 0.)
224 *
225 * check_user_mbz() combines checking that the user pointer is accessible
226 * and that the contained value is zero.
227 *
228 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
229 */
230#define check_user_mbz(U) ({ \
231 typeof(*(U)) mbz__; \
232 get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0; \
233})
234
235static inline u64 ptr_to_u64(const void *ptr)
236{
237 return (uintptr_t)ptr;
238}
239
240#define u64_to_ptr(T, x) ({ \
241 typecheck(u64, x); \
242 (T *)(uintptr_t)(x); \
243})
244
245#define __mask_next_bit(mask) ({ \
246 int __idx = ffs(mask) - 1; \
247 mask &= ~BIT(__idx); \
248 __idx; \
249})
250
251static inline bool is_power_of_2_u64(u64 n)
252{
253 return (n != 0 && ((n & (n - 1)) == 0));
254}
255
256static inline void __list_del_many(struct list_head *head,
257 struct list_head *first)
258{
259 first->prev = head;
260 WRITE_ONCE(head->next, first);
261}
262
263static inline int list_is_last_rcu(const struct list_head *list,
264 const struct list_head *head)
265{
266 return READ_ONCE(list->next) == head;
267}
268
269static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
270{
271 unsigned long j = msecs_to_jiffies(m);
272
273 return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
274}
275
276/*
277 * If you need to wait X milliseconds between events A and B, but event B
278 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
279 * when event A happened, then just before event B you call this function and
280 * pass the timestamp as the first argument, and X as the second argument.
281 */
282static inline void
283wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
284{
285 unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
286
287 /*
288 * Don't re-read the value of "jiffies" every time since it may change
289 * behind our back and break the math.
290 */
291 tmp_jiffies = jiffies;
292 target_jiffies = timestamp_jiffies +
293 msecs_to_jiffies_timeout(to_wait_ms);
294
295 if (time_after(target_jiffies, tmp_jiffies)) {
296 remaining_jiffies = target_jiffies - tmp_jiffies;
297 while (remaining_jiffies)
298 remaining_jiffies =
299 schedule_timeout_uninterruptible(remaining_jiffies);
300 }
301}
302
303/**
304 * __wait_for - magic wait macro
305 *
306 * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
307 * important that we check the condition again after having timed out, since the
308 * timeout could be due to preemption or similar and we've never had a chance to
309 * check the condition before the timeout.
310 */
311#define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
312 const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
313 long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
314 int ret__; \
315 might_sleep(); \
316 for (;;) { \
317 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
318 OP; \
319 /* Guarantee COND check prior to timeout */ \
320 barrier(); \
321 if (COND) { \
322 ret__ = 0; \
323 break; \
324 } \
325 if (expired__) { \
326 ret__ = -ETIMEDOUT; \
327 break; \
328 } \
329 usleep_range(wait__, wait__ * 2); \
330 if (wait__ < (Wmax)) \
331 wait__ <<= 1; \
332 } \
333 ret__; \
334})
335
336#define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
337 (Wmax))
338#define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000)
339
340/* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
341#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
342# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
343#else
344# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
345#endif
346
347#define _wait_for_atomic(COND, US, ATOMIC) \
348({ \
349 int cpu, ret, timeout = (US) * 1000; \
350 u64 base; \
351 _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
352 if (!(ATOMIC)) { \
353 preempt_disable(); \
354 cpu = smp_processor_id(); \
355 } \
356 base = local_clock(); \
357 for (;;) { \
358 u64 now = local_clock(); \
359 if (!(ATOMIC)) \
360 preempt_enable(); \
361 /* Guarantee COND check prior to timeout */ \
362 barrier(); \
363 if (COND) { \
364 ret = 0; \
365 break; \
366 } \
367 if (now - base >= timeout) { \
368 ret = -ETIMEDOUT; \
369 break; \
370 } \
371 cpu_relax(); \
372 if (!(ATOMIC)) { \
373 preempt_disable(); \
374 if (unlikely(cpu != smp_processor_id())) { \
375 timeout -= now - base; \
376 cpu = smp_processor_id(); \
377 base = local_clock(); \
378 } \
379 } \
380 } \
381 ret; \
382})
383
384#define wait_for_us(COND, US) \
385({ \
386 int ret__; \
387 BUILD_BUG_ON(!__builtin_constant_p(US)); \
388 if ((US) > 10) \
389 ret__ = _wait_for((COND), (US), 10, 10); \
390 else \
391 ret__ = _wait_for_atomic((COND), (US), 0); \
392 ret__; \
393})
394
395#define wait_for_atomic_us(COND, US) \
396({ \
397 BUILD_BUG_ON(!__builtin_constant_p(US)); \
398 BUILD_BUG_ON((US) > 50000); \
399 _wait_for_atomic((COND), (US), 1); \
400})
401
402#define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
403
404#define KHz(x) (1000 * (x))
405#define MHz(x) KHz(1000 * (x))
406
407#define KBps(x) (1000 * (x))
408#define MBps(x) KBps(1000 * (x))
409#define GBps(x) ((u64)1000 * MBps((x)))
410
411static inline const char *yesno(bool v)
412{
413 return v ? "yes" : "no";
414}
415
416static inline const char *onoff(bool v)
417{
418 return v ? "on" : "off";
419}
420
421static inline const char *enableddisabled(bool v)
422{
423 return v ? "enabled" : "disabled";
424}
425
426void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
427static inline void __add_taint_for_CI(unsigned int taint)
428{
429 /*
430 * The system is "ok", just about surviving for the user, but
431 * CI results are now unreliable as the HW is very suspect.
432 * CI checks the taint state after every test and will reboot
433 * the machine if the kernel is tainted.
434 */
435 add_taint(taint, LOCKDEP_STILL_OK);
436}
437
438void cancel_timer(struct timer_list *t);
439void set_timer_ms(struct timer_list *t, unsigned long timeout);
440
441static inline bool timer_expired(const struct timer_list *t)
442{
443 return READ_ONCE(t->expires) && !timer_pending(t);
444}
445
446/*
447 * This is a lookalike for IS_ENABLED() that takes a kconfig value,
448 * e.g. CONFIG_DRM_I915_SPIN_REQUEST, and evaluates whether it is non-zero
449 * i.e. whether the configuration is active. Wrapping up the config inside
450 * a boolean context prevents clang and smatch from complaining about potential
451 * issues in confusing logical-&& with bitwise-& for constants.
452 *
453 * Sadly IS_ENABLED() itself does not work with kconfig values.
454 *
455 * Returns 0 if @config is 0, 1 if set to any value.
456 */
457#define IS_ACTIVE(config) ((config) != 0)
458
459#endif /* !__I915_UTILS_H */