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 MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
44 __stringify(x), (long)(x))
45
46 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
47
48 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
49 const char *func, int line);
50 #define i915_inject_probe_error(_i915, _err) \
51 __i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
52 bool i915_error_injected(void);
53
54 #else
55
56 #define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
57 #define i915_error_injected() false
58
59 #endif
60
61 #define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
62
63 #define i915_probe_error(i915, fmt, ...) ({ \
64 if (i915_error_injected()) \
65 drm_dbg(&(i915)->drm, fmt, ##__VA_ARGS__); \
66 else \
67 drm_err(&(i915)->drm, fmt, ##__VA_ARGS__); \
68 })
69
70 #define range_overflows(start, size, max) ({ \
71 typeof(start) start__ = (start); \
72 typeof(size) size__ = (size); \
73 typeof(max) max__ = (max); \
74 (void)(&start__ == &size__); \
75 (void)(&start__ == &max__); \
76 start__ >= max__ || size__ > max__ - start__; \
77 })
78
79 #define range_overflows_t(type, start, size, max) \
80 range_overflows((type)(start), (type)(size), (type)(max))
81
82 #define range_overflows_end(start, size, max) ({ \
83 typeof(start) start__ = (start); \
84 typeof(size) size__ = (size); \
85 typeof(max) max__ = (max); \
86 (void)(&start__ == &size__); \
87 (void)(&start__ == &max__); \
88 start__ > max__ || size__ > max__ - start__; \
89 })
90
91 #define range_overflows_end_t(type, start, size, max) \
92 range_overflows_end((type)(start), (type)(size), (type)(max))
93
94 #define ptr_mask_bits(ptr, n) ({ \
95 unsigned long __v = (unsigned long)(ptr); \
96 (typeof(ptr))(__v & -BIT(n)); \
97 })
98
99 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
100
101 #define ptr_unpack_bits(ptr, bits, n) ({ \
102 unsigned long __v = (unsigned long)(ptr); \
103 *(bits) = __v & (BIT(n) - 1); \
104 (typeof(ptr))(__v & -BIT(n)); \
105 })
106
107 #define ptr_pack_bits(ptr, bits, n) ({ \
108 unsigned long __bits = (bits); \
109 GEM_BUG_ON(__bits & -BIT(n)); \
110 ((typeof(ptr))((unsigned long)(ptr) | __bits)); \
111 })
112
113 #define ptr_dec(ptr) ({ \
114 unsigned long __v = (unsigned long)(ptr); \
115 (typeof(ptr))(__v - 1); \
116 })
117
118 #define ptr_inc(ptr) ({ \
119 unsigned long __v = (unsigned long)(ptr); \
120 (typeof(ptr))(__v + 1); \
121 })
122
123 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
124 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
125 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
126 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
127
128 #define fetch_and_zero(ptr) ({ \
129 typeof(*ptr) __T = *(ptr); \
130 *(ptr) = (typeof(*ptr))0; \
131 __T; \
132 })
133
ptrdiff(const void * a,const void * b)134 static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
135 {
136 return a - b;
137 }
138
139 /*
140 * container_of_user: Extract the superclass from a pointer to a member.
141 *
142 * Exactly like container_of() with the exception that it plays nicely
143 * with sparse for __user @ptr.
144 */
145 #define container_of_user(ptr, type, member) ({ \
146 void __user *__mptr = (void __user *)(ptr); \
147 BUILD_BUG_ON_MSG(!__same_type(*(ptr), typeof_member(type, member)) && \
148 !__same_type(*(ptr), void), \
149 "pointer type mismatch in container_of()"); \
150 ((type __user *)(__mptr - offsetof(type, member))); })
151
152 /*
153 * check_user_mbz: Check that a user value exists and is zero
154 *
155 * Frequently in our uABI we reserve space for future extensions, and
156 * two ensure that userspace is prepared we enforce that space must
157 * be zero. (Then any future extension can safely assume a default value
158 * of 0.)
159 *
160 * check_user_mbz() combines checking that the user pointer is accessible
161 * and that the contained value is zero.
162 *
163 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
164 */
165 #define check_user_mbz(U) ({ \
166 typeof(*(U)) mbz__; \
167 get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0; \
168 })
169
170 #define u64_to_ptr(T, x) ({ \
171 typecheck(u64, x); \
172 (T *)(uintptr_t)(x); \
173 })
174
175 #define __mask_next_bit(mask) ({ \
176 int __idx = ffs(mask) - 1; \
177 mask &= ~BIT(__idx); \
178 __idx; \
179 })
180
is_power_of_2_u64(u64 n)181 static inline bool is_power_of_2_u64(u64 n)
182 {
183 return (n != 0 && ((n & (n - 1)) == 0));
184 }
185
__list_del_many(struct list_head * head,struct list_head * first)186 static inline void __list_del_many(struct list_head *head,
187 struct list_head *first)
188 {
189 first->prev = head;
190 WRITE_ONCE(head->next, first);
191 }
192
list_is_last_rcu(const struct list_head * list,const struct list_head * head)193 static inline int list_is_last_rcu(const struct list_head *list,
194 const struct list_head *head)
195 {
196 return READ_ONCE(list->next) == head;
197 }
198
msecs_to_jiffies_timeout(const unsigned int m)199 static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
200 {
201 unsigned long j = msecs_to_jiffies(m);
202
203 return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
204 }
205
206 /*
207 * If you need to wait X milliseconds between events A and B, but event B
208 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
209 * when event A happened, then just before event B you call this function and
210 * pass the timestamp as the first argument, and X as the second argument.
211 */
212 static inline void
wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies,int to_wait_ms)213 wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
214 {
215 unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
216
217 /*
218 * Don't re-read the value of "jiffies" every time since it may change
219 * behind our back and break the math.
220 */
221 tmp_jiffies = jiffies;
222 target_jiffies = timestamp_jiffies +
223 msecs_to_jiffies_timeout(to_wait_ms);
224
225 if (time_after(target_jiffies, tmp_jiffies)) {
226 remaining_jiffies = target_jiffies - tmp_jiffies;
227 while (remaining_jiffies)
228 remaining_jiffies =
229 schedule_timeout_uninterruptible(remaining_jiffies);
230 }
231 }
232
233 /*
234 * __wait_for - magic wait macro
235 *
236 * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
237 * important that we check the condition again after having timed out, since the
238 * timeout could be due to preemption or similar and we've never had a chance to
239 * check the condition before the timeout.
240 */
241 #define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
242 const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
243 long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
244 int ret__; \
245 might_sleep(); \
246 for (;;) { \
247 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
248 OP; \
249 /* Guarantee COND check prior to timeout */ \
250 barrier(); \
251 if (COND) { \
252 ret__ = 0; \
253 break; \
254 } \
255 if (expired__) { \
256 ret__ = -ETIMEDOUT; \
257 break; \
258 } \
259 usleep_range(wait__, wait__ * 2); \
260 if (wait__ < (Wmax)) \
261 wait__ <<= 1; \
262 } \
263 ret__; \
264 })
265
266 #define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
267 (Wmax))
268 #define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000)
269
270 /* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
271 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG) && IS_ENABLED(CONFIG_PREEMPT_COUNT)
272 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
273 #else
274 # define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
275 #endif
276
277 #define _wait_for_atomic(COND, US, ATOMIC) \
278 ({ \
279 int cpu, ret, timeout = (US) * 1000; \
280 u64 base; \
281 _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
282 if (!(ATOMIC)) { \
283 preempt_disable(); \
284 cpu = smp_processor_id(); \
285 } \
286 base = local_clock(); \
287 for (;;) { \
288 u64 now = local_clock(); \
289 if (!(ATOMIC)) \
290 preempt_enable(); \
291 /* Guarantee COND check prior to timeout */ \
292 barrier(); \
293 if (COND) { \
294 ret = 0; \
295 break; \
296 } \
297 if (now - base >= timeout) { \
298 ret = -ETIMEDOUT; \
299 break; \
300 } \
301 cpu_relax(); \
302 if (!(ATOMIC)) { \
303 preempt_disable(); \
304 if (unlikely(cpu != smp_processor_id())) { \
305 timeout -= now - base; \
306 cpu = smp_processor_id(); \
307 base = local_clock(); \
308 } \
309 } \
310 } \
311 ret; \
312 })
313
314 #define wait_for_us(COND, US) \
315 ({ \
316 int ret__; \
317 BUILD_BUG_ON(!__builtin_constant_p(US)); \
318 if ((US) > 10) \
319 ret__ = _wait_for((COND), (US), 10, 10); \
320 else \
321 ret__ = _wait_for_atomic((COND), (US), 0); \
322 ret__; \
323 })
324
325 #define wait_for_atomic_us(COND, US) \
326 ({ \
327 BUILD_BUG_ON(!__builtin_constant_p(US)); \
328 BUILD_BUG_ON((US) > 50000); \
329 _wait_for_atomic((COND), (US), 1); \
330 })
331
332 #define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
333
334 #define KHz(x) (1000 * (x))
335 #define MHz(x) KHz(1000 * (x))
336
337 void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
__add_taint_for_CI(unsigned int taint)338 static inline void __add_taint_for_CI(unsigned int taint)
339 {
340 /*
341 * The system is "ok", just about surviving for the user, but
342 * CI results are now unreliable as the HW is very suspect.
343 * CI checks the taint state after every test and will reboot
344 * the machine if the kernel is tainted.
345 */
346 add_taint(taint, LOCKDEP_STILL_OK);
347 }
348
349 void cancel_timer(struct timer_list *t);
350 void set_timer_ms(struct timer_list *t, unsigned long timeout);
351
timer_active(const struct timer_list * t)352 static inline bool timer_active(const struct timer_list *t)
353 {
354 return READ_ONCE(t->expires);
355 }
356
timer_expired(const struct timer_list * t)357 static inline bool timer_expired(const struct timer_list *t)
358 {
359 return timer_active(t) && !timer_pending(t);
360 }
361
i915_run_as_guest(void)362 static inline bool i915_run_as_guest(void)
363 {
364 #if IS_ENABLED(CONFIG_X86)
365 return !hypervisor_is_type(X86_HYPER_NATIVE);
366 #else
367 /* Not supported yet */
368 return false;
369 #endif
370 }
371
372 bool i915_vtd_active(struct drm_i915_private *i915);
373
374 bool i915_direct_stolen_access(struct drm_i915_private *i915);
375
376 #endif /* !__I915_UTILS_H */
377