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 #define drm_i915_private inteldrm_softc
41
42 struct drm_i915_private;
43 struct timeout;
44
45 #define FDO_BUG_URL "https://gitlab.freedesktop.org/drm/intel/-/wikis/How-to-file-i915-bugs"
46
47 #define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
48 __stringify(x), (long)(x))
49
50 void __printf(3, 4)
51 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
52 const char *fmt, ...);
53
54 #define i915_report_error(dev_priv, fmt, ...) \
55 __i915_printk(dev_priv, KERN_ERR, fmt, ##__VA_ARGS__)
56
57 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
58
59 int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
60 const char *func, int line);
61 #define i915_inject_probe_error(_i915, _err) \
62 __i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
63 bool i915_error_injected(void);
64
65 #else
66
67 #define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
68 #define i915_error_injected() false
69
70 #endif
71
72 #define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
73
74 #define i915_probe_error(i915, fmt, ...) \
75 __i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \
76 fmt, ##__VA_ARGS__)
77
78 #if defined(GCC_VERSION) && GCC_VERSION >= 70000
79 #define add_overflows_t(T, A, B) \
80 __builtin_add_overflow_p((A), (B), (T)0)
81 #else
82 #define add_overflows_t(T, A, B) ({ \
83 typeof(A) a = (A); \
84 typeof(B) b = (B); \
85 (T)(a + b) < a; \
86 })
87 #endif
88
89 #define add_overflows(A, B) \
90 add_overflows_t(typeof((A) + (B)), (A), (B))
91
92 #define range_overflows(start, size, max) ({ \
93 typeof(start) start__ = (start); \
94 typeof(size) size__ = (size); \
95 typeof(max) max__ = (max); \
96 (void)(&start__ == &size__); \
97 (void)(&start__ == &max__); \
98 start__ >= max__ || size__ > max__ - start__; \
99 })
100
101 #define range_overflows_t(type, start, size, max) \
102 range_overflows((type)(start), (type)(size), (type)(max))
103
104 #define range_overflows_end(start, size, max) ({ \
105 typeof(start) start__ = (start); \
106 typeof(size) size__ = (size); \
107 typeof(max) max__ = (max); \
108 (void)(&start__ == &size__); \
109 (void)(&start__ == &max__); \
110 start__ > max__ || size__ > max__ - start__; \
111 })
112
113 #define range_overflows_end_t(type, start, size, max) \
114 range_overflows_end((type)(start), (type)(size), (type)(max))
115
116 /* Note we don't consider signbits :| */
117 #define overflows_type(x, T) \
118 (sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))
119
120 #define ptr_mask_bits(ptr, n) ({ \
121 unsigned long __v = (unsigned long)(ptr); \
122 (typeof(ptr))(__v & -BIT(n)); \
123 })
124
125 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
126
127 #define ptr_unpack_bits(ptr, bits, n) ({ \
128 unsigned long __v = (unsigned long)(ptr); \
129 *(bits) = __v & (BIT(n) - 1); \
130 (typeof(ptr))(__v & -BIT(n)); \
131 })
132
133 #define ptr_pack_bits(ptr, bits, n) ({ \
134 unsigned long __bits = (bits); \
135 GEM_BUG_ON(__bits & -BIT(n)); \
136 ((typeof(ptr))((unsigned long)(ptr) | __bits)); \
137 })
138
139 #define ptr_dec(ptr) ({ \
140 unsigned long __v = (unsigned long)(ptr); \
141 (typeof(ptr))(__v - 1); \
142 })
143
144 #define ptr_inc(ptr) ({ \
145 unsigned long __v = (unsigned long)(ptr); \
146 (typeof(ptr))(__v + 1); \
147 })
148
149 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
150 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
151 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
152 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
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), typeof_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 timeout *t);
376 void set_timer_ms(struct timeout *t, unsigned long timeout);
377
timer_active(const struct timeout * t)378 static inline bool timer_active(const struct timeout *t)
379 {
380 #ifdef __linux__
381 return READ_ONCE(t->expires);
382 #else
383 return READ_ONCE(t->to_time);
384 #endif
385 }
386
timer_expired(const struct timeout * t)387 static inline bool timer_expired(const struct timeout *t)
388 {
389 return timer_active(t) && !timer_pending(t);
390 }
391
i915_run_as_guest(void)392 static inline bool i915_run_as_guest(void)
393 {
394 #if IS_ENABLED(CONFIG_X86)
395 return !hypervisor_is_type(X86_HYPER_NATIVE);
396 #else
397 /* Not supported yet */
398 return false;
399 #endif
400 }
401
402 bool i915_vtd_active(struct drm_i915_private *i915);
403
404 #endif /* !__I915_UTILS_H */
405