summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/i915/i915_utils.h
blob: 03a73d2bd50db3d8a393d1297f42fa4b41021d77 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
/*
 * Copyright © 2016 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

#ifndef __I915_UTILS_H
#define __I915_UTILS_H

#include <linux/list.h>
#include <linux/overflow.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/workqueue.h>

struct drm_i915_private;
struct timer_list;

#define FDO_BUG_URL "https://gitlab.freedesktop.org/drm/intel/-/wikis/How-to-file-i915-bugs"

#undef WARN_ON
/* Many gcc seem to no see through this and fall over :( */
#if 0
#define WARN_ON(x) ({ \
	bool __i915_warn_cond = (x); \
	if (__builtin_constant_p(__i915_warn_cond)) \
		BUILD_BUG_ON(__i915_warn_cond); \
	WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
#else
#define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
#endif

#undef WARN_ON_ONCE
#define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")")

#define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
			     __stringify(x), (long)(x))

void __printf(3, 4)
__i915_printk(struct drm_i915_private *dev_priv, const char *level,
	      const char *fmt, ...);

#define i915_report_error(dev_priv, fmt, ...)				   \
	__i915_printk(dev_priv, KERN_ERR, fmt, ##__VA_ARGS__)

#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)

int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
			      const char *func, int line);
#define i915_inject_probe_error(_i915, _err) \
	__i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
bool i915_error_injected(void);

#else

#define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
#define i915_error_injected() false

#endif

#define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)

#define i915_probe_error(i915, fmt, ...)				   \
	__i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \
		      fmt, ##__VA_ARGS__)

#if defined(GCC_VERSION) && GCC_VERSION >= 70000
#define add_overflows_t(T, A, B) \
	__builtin_add_overflow_p((A), (B), (T)0)
#else
#define add_overflows_t(T, A, B) ({ \
	typeof(A) a = (A); \
	typeof(B) b = (B); \
	(T)(a + b) < a; \
})
#endif

#define add_overflows(A, B) \
	add_overflows_t(typeof((A) + (B)), (A), (B))

#define range_overflows(start, size, max) ({ \
	typeof(start) start__ = (start); \
	typeof(size) size__ = (size); \
	typeof(max) max__ = (max); \
	(void)(&start__ == &size__); \
	(void)(&start__ == &max__); \
	start__ >= max__ || size__ > max__ - start__; \
})

#define range_overflows_t(type, start, size, max) \
	range_overflows((type)(start), (type)(size), (type)(max))

#define range_overflows_end(start, size, max) ({ \
	typeof(start) start__ = (start); \
	typeof(size) size__ = (size); \
	typeof(max) max__ = (max); \
	(void)(&start__ == &size__); \
	(void)(&start__ == &max__); \
	start__ > max__ || size__ > max__ - start__; \
})

#define range_overflows_end_t(type, start, size, max) \
	range_overflows_end((type)(start), (type)(size), (type)(max))

/* Note we don't consider signbits :| */
#define overflows_type(x, T) \
	(sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))

static inline bool
__check_struct_size(size_t base, size_t arr, size_t count, size_t *size)
{
	size_t sz;

	if (check_mul_overflow(count, arr, &sz))
		return false;

	if (check_add_overflow(sz, base, &sz))
		return false;

	*size = sz;
	return true;
}

/**
 * check_struct_size() - Calculate size of structure with trailing array.
 * @p: Pointer to the structure.
 * @member: Name of the array member.
 * @n: Number of elements in the array.
 * @sz: Total size of structure and array
 *
 * Calculates size of memory needed for structure @p followed by an
 * array of @n @member elements, like struct_size() but reports
 * whether it overflowed, and the resultant size in @sz
 *
 * Return: false if the calculation overflowed.
 */
#define check_struct_size(p, member, n, sz) \
	likely(__check_struct_size(sizeof(*(p)), \
				   sizeof(*(p)->member) + __must_be_array((p)->member), \
				   n, sz))

#define ptr_mask_bits(ptr, n) ({					\
	unsigned long __v = (unsigned long)(ptr);			\
	(typeof(ptr))(__v & -BIT(n));					\
})

#define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))

#define ptr_unpack_bits(ptr, bits, n) ({				\
	unsigned long __v = (unsigned long)(ptr);			\
	*(bits) = __v & (BIT(n) - 1);					\
	(typeof(ptr))(__v & -BIT(n));					\
})

#define ptr_pack_bits(ptr, bits, n) ({					\
	unsigned long __bits = (bits);					\
	GEM_BUG_ON(__bits & -BIT(n));					\
	((typeof(ptr))((unsigned long)(ptr) | __bits));			\
})

#define ptr_dec(ptr) ({							\
	unsigned long __v = (unsigned long)(ptr);			\
	(typeof(ptr))(__v - 1);						\
})

#define ptr_inc(ptr) ({							\
	unsigned long __v = (unsigned long)(ptr);			\
	(typeof(ptr))(__v + 1);						\
})

#define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
#define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)

#define struct_member(T, member) (((T *)0)->member)

#define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)

#define fetch_and_zero(ptr) ({						\
	typeof(*ptr) __T = *(ptr);					\
	*(ptr) = (typeof(*ptr))0;					\
	__T;								\
})

/*
 * container_of_user: Extract the superclass from a pointer to a member.
 *
 * Exactly like container_of() with the exception that it plays nicely
 * with sparse for __user @ptr.
 */
#define container_of_user(ptr, type, member) ({				\
	void __user *__mptr = (void __user *)(ptr);			\
	BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
			 !__same_type(*(ptr), void),			\
			 "pointer type mismatch in container_of()");	\
	((type __user *)(__mptr - offsetof(type, member))); })

/*
 * check_user_mbz: Check that a user value exists and is zero
 *
 * Frequently in our uABI we reserve space for future extensions, and
 * two ensure that userspace is prepared we enforce that space must
 * be zero. (Then any future extension can safely assume a default value
 * of 0.)
 *
 * check_user_mbz() combines checking that the user pointer is accessible
 * and that the contained value is zero.
 *
 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
 */
#define check_user_mbz(U) ({						\
	typeof(*(U)) mbz__;						\
	get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;		\
})

static inline u64 ptr_to_u64(const void *ptr)
{
	return (uintptr_t)ptr;
}

#define u64_to_ptr(T, x) ({						\
	typecheck(u64, x);						\
	(T *)(uintptr_t)(x);						\
})

#define __mask_next_bit(mask) ({					\
	int __idx = ffs(mask) - 1;					\
	mask &= ~BIT(__idx);						\
	__idx;								\
})

static inline bool is_power_of_2_u64(u64 n)
{
	return (n != 0 && ((n & (n - 1)) == 0));
}

static inline void __list_del_many(struct list_head *head,
				   struct list_head *first)
{
	first->prev = head;
	WRITE_ONCE(head->next, first);
}

static inline int list_is_last_rcu(const struct list_head *list,
				   const struct list_head *head)
{
	return READ_ONCE(list->next) == head;
}

/*
 * Wait until the work is finally complete, even if it tries to postpone
 * by requeueing itself. Note, that if the worker never cancels itself,
 * we will spin forever.
 */
static inline void drain_delayed_work(struct delayed_work *dw)
{
	do {
		while (flush_delayed_work(dw))
			;
	} while (delayed_work_pending(dw));
}

static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
{
	unsigned long j = msecs_to_jiffies(m);

	return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
}

/*
 * If you need to wait X milliseconds between events A and B, but event B
 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
 * when event A happened, then just before event B you call this function and
 * pass the timestamp as the first argument, and X as the second argument.
 */
static inline void
wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
{
	unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;

	/*
	 * Don't re-read the value of "jiffies" every time since it may change
	 * behind our back and break the math.
	 */
	tmp_jiffies = jiffies;
	target_jiffies = timestamp_jiffies +
			 msecs_to_jiffies_timeout(to_wait_ms);

	if (time_after(target_jiffies, tmp_jiffies)) {
		remaining_jiffies = target_jiffies - tmp_jiffies;
		while (remaining_jiffies)
			remaining_jiffies =
			    schedule_timeout_uninterruptible(remaining_jiffies);
	}
}

/**
 * __wait_for - magic wait macro
 *
 * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
 * important that we check the condition again after having timed out, since the
 * timeout could be due to preemption or similar and we've never had a chance to
 * check the condition before the timeout.
 */
#define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
	const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
	long wait__ = (Wmin); /* recommended min for usleep is 10 us */	\
	int ret__;							\
	might_sleep();							\
	for (;;) {							\
		const bool expired__ = ktime_after(ktime_get_raw(), end__); \
		OP;							\
		/* Guarantee COND check prior to timeout */		\
		barrier();						\
		if (COND) {						\
			ret__ = 0;					\
			break;						\
		}							\
		if (expired__) {					\
			ret__ = -ETIMEDOUT;				\
			break;						\
		}							\
		usleep_range(wait__, wait__ * 2);			\
		if (wait__ < (Wmax))					\
			wait__ <<= 1;					\
	}								\
	ret__;								\
})

#define _wait_for(COND, US, Wmin, Wmax)	__wait_for(, (COND), (US), (Wmin), \
						   (Wmax))
#define wait_for(COND, MS)		_wait_for((COND), (MS) * 1000, 10, 1000)

/* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
#else
# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
#endif

#define _wait_for_atomic(COND, US, ATOMIC) \
({ \
	int cpu, ret, timeout = (US) * 1000; \
	u64 base; \
	_WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
	if (!(ATOMIC)) { \
		preempt_disable(); \
		cpu = smp_processor_id(); \
	} \
	base = local_clock(); \
	for (;;) { \
		u64 now = local_clock(); \
		if (!(ATOMIC)) \
			preempt_enable(); \
		/* Guarantee COND check prior to timeout */ \
		barrier(); \
		if (COND) { \
			ret = 0; \
			break; \
		} \
		if (now - base >= timeout) { \
			ret = -ETIMEDOUT; \
			break; \
		} \
		cpu_relax(); \
		if (!(ATOMIC)) { \
			preempt_disable(); \
			if (unlikely(cpu != smp_processor_id())) { \
				timeout -= now - base; \
				cpu = smp_processor_id(); \
				base = local_clock(); \
			} \
		} \
	} \
	ret; \
})

#define wait_for_us(COND, US) \
({ \
	int ret__; \
	BUILD_BUG_ON(!__builtin_constant_p(US)); \
	if ((US) > 10) \
		ret__ = _wait_for((COND), (US), 10, 10); \
	else \
		ret__ = _wait_for_atomic((COND), (US), 0); \
	ret__; \
})

#define wait_for_atomic_us(COND, US) \
({ \
	BUILD_BUG_ON(!__builtin_constant_p(US)); \
	BUILD_BUG_ON((US) > 50000); \
	_wait_for_atomic((COND), (US), 1); \
})

#define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)

#define KHz(x) (1000 * (x))
#define MHz(x) KHz(1000 * (x))

#define KBps(x) (1000 * (x))
#define MBps(x) KBps(1000 * (x))
#define GBps(x) ((u64)1000 * MBps((x)))

static inline const char *yesno(bool v)
{
	return v ? "yes" : "no";
}

static inline const char *onoff(bool v)
{
	return v ? "on" : "off";
}

static inline const char *enableddisabled(bool v)
{
	return v ? "enabled" : "disabled";
}

static inline void add_taint_for_CI(unsigned int taint)
{
	/*
	 * The system is "ok", just about surviving for the user, but
	 * CI results are now unreliable as the HW is very suspect.
	 * CI checks the taint state after every test and will reboot
	 * the machine if the kernel is tainted.
	 */
	add_taint(taint, LOCKDEP_STILL_OK);
}

void cancel_timer(struct timer_list *t);
void set_timer_ms(struct timer_list *t, unsigned long timeout);

static inline bool timer_expired(const struct timer_list *t)
{
	return READ_ONCE(t->expires) && !timer_pending(t);
}

/*
 * This is a lookalike for IS_ENABLED() that takes a kconfig value,
 * e.g. CONFIG_DRM_I915_SPIN_REQUEST, and evaluates whether it is non-zero
 * i.e. whether the configuration is active. Wrapping up the config inside
 * a boolean context prevents clang and smatch from complaining about potential
 * issues in confusing logical-&& with bitwise-& for constants.
 *
 * Sadly IS_ENABLED() itself does not work with kconfig values.
 *
 * Returns 0 if @config is 0, 1 if set to any value.
 */
#define IS_ACTIVE(config) ((config) != 0)

#endif /* !__I915_UTILS_H */