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 
ptrdiff(const void * a,const void * b)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 
is_power_of_2_u64(u64 n)207 static inline bool is_power_of_2_u64(u64 n)
208 {
209 	return (n != 0 && ((n & (n - 1)) == 0));
210 }
211 
__list_del_many(struct list_head * head,struct list_head * first)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 
list_is_last_rcu(const struct list_head * list,const struct list_head * head)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 
msecs_to_jiffies_timeout(const unsigned int m)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
wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies,int to_wait_ms)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);
__add_taint_for_CI(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 
timer_active(const struct timer_list * t)378 static inline bool timer_active(const struct timer_list *t)
379 {
380 	return READ_ONCE(t->expires);
381 }
382 
timer_expired(const struct timer_list * t)383 static inline bool timer_expired(const struct timer_list *t)
384 {
385 	return timer_active(t) && !timer_pending(t);
386 }
387 
i915_run_as_guest(void)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 */
401