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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/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
40struct drm_i915_private;
41struct timer_list;
42
43#define FDO_BUG_URL "https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html"
44
45#define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
46 __stringify(x), (long)(x))
47
48#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
49
50int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
51 const char *func, int line);
52#define i915_inject_probe_error(_i915, _err) \
53 __i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
54bool i915_error_injected(void);
55
56#else
57
58#define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
59#define i915_error_injected() false
60
61#endif
62
63#define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
64
65#define i915_probe_error(i915, fmt, ...) ({ \
66 if (i915_error_injected()) \
67 drm_dbg(&(i915)->drm, fmt, ##__VA_ARGS__); \
68 else \
69 drm_err(&(i915)->drm, fmt, ##__VA_ARGS__); \
70})
71
72#define range_overflows(start, size, max) ({ \
73 typeof(start) start__ = (start); \
74 typeof(size) size__ = (size); \
75 typeof(max) max__ = (max); \
76 (void)(&start__ == &size__); \
77 (void)(&start__ == &max__); \
78 start__ >= max__ || size__ > max__ - start__; \
79})
80
81#define range_overflows_t(type, start, size, max) \
82 range_overflows((type)(start), (type)(size), (type)(max))
83
84#define range_overflows_end(start, size, max) ({ \
85 typeof(start) start__ = (start); \
86 typeof(size) size__ = (size); \
87 typeof(max) max__ = (max); \
88 (void)(&start__ == &size__); \
89 (void)(&start__ == &max__); \
90 start__ > max__ || size__ > max__ - start__; \
91})
92
93#define range_overflows_end_t(type, start, size, max) \
94 range_overflows_end((type)(start), (type)(size), (type)(max))
95
96#define ptr_mask_bits(ptr, n) ({ \
97 unsigned long __v = (unsigned long)(ptr); \
98 (typeof(ptr))(__v & -BIT(n)); \
99})
100
101#define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
102
103#define ptr_unpack_bits(ptr, bits, n) ({ \
104 unsigned long __v = (unsigned long)(ptr); \
105 *(bits) = __v & (BIT(n) - 1); \
106 (typeof(ptr))(__v & -BIT(n)); \
107})
108
109#define ptr_pack_bits(ptr, bits, n) ({ \
110 unsigned long __bits = (bits); \
111 GEM_BUG_ON(__bits & -BIT(n)); \
112 ((typeof(ptr))((unsigned long)(ptr) | __bits)); \
113})
114
115#define ptr_dec(ptr) ({ \
116 unsigned long __v = (unsigned long)(ptr); \
117 (typeof(ptr))(__v - 1); \
118})
119
120#define ptr_inc(ptr) ({ \
121 unsigned long __v = (unsigned long)(ptr); \
122 (typeof(ptr))(__v + 1); \
123})
124
125#define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
126#define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
127#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
128#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
129
130#define fetch_and_zero(ptr) ({ \
131 typeof(*ptr) __T = *(ptr); \
132 *(ptr) = (typeof(*ptr))0; \
133 __T; \
134})
135
136static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
137{
138 return a - b;
139}
140
141/*
142 * container_of_user: Extract the superclass from a pointer to a member.
143 *
144 * Exactly like container_of() with the exception that it plays nicely
145 * with sparse for __user @ptr.
146 */
147#define container_of_user(ptr, type, member) ({ \
148 void __user *__mptr = (void __user *)(ptr); \
149 BUILD_BUG_ON_MSG(!__same_type(*(ptr), typeof_member(type, member)) && \
150 !__same_type(*(ptr), void), \
151 "pointer type mismatch in container_of()"); \
152 ((type __user *)(__mptr - offsetof(type, member))); })
153
154/*
155 * check_user_mbz: Check that a user value exists and is zero
156 *
157 * Frequently in our uABI we reserve space for future extensions, and
158 * two ensure that userspace is prepared we enforce that space must
159 * be zero. (Then any future extension can safely assume a default value
160 * of 0.)
161 *
162 * check_user_mbz() combines checking that the user pointer is accessible
163 * and that the contained value is zero.
164 *
165 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
166 */
167#define check_user_mbz(U) ({ \
168 typeof(*(U)) mbz__; \
169 get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0; \
170})
171
172#define u64_to_ptr(T, x) ({ \
173 typecheck(u64, x); \
174 (T *)(uintptr_t)(x); \
175})
176
177#define __mask_next_bit(mask) ({ \
178 int __idx = ffs(mask) - 1; \
179 mask &= ~BIT(__idx); \
180 __idx; \
181})
182
183static inline bool is_power_of_2_u64(u64 n)
184{
185 return (n != 0 && ((n & (n - 1)) == 0));
186}
187
188static inline void __list_del_many(struct list_head *head,
189 struct list_head *first)
190{
191 first->prev = head;
192 WRITE_ONCE(head->next, first);
193}
194
195static inline int list_is_last_rcu(const struct list_head *list,
196 const struct list_head *head)
197{
198 return READ_ONCE(list->next) == head;
199}
200
201static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
202{
203 unsigned long j = msecs_to_jiffies(m);
204
205 return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
206}
207
208/*
209 * If you need to wait X milliseconds between events A and B, but event B
210 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
211 * when event A happened, then just before event B you call this function and
212 * pass the timestamp as the first argument, and X as the second argument.
213 */
214static inline void
215wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
216{
217 unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
218
219 /*
220 * Don't re-read the value of "jiffies" every time since it may change
221 * behind our back and break the math.
222 */
223 tmp_jiffies = jiffies;
224 target_jiffies = timestamp_jiffies +
225 msecs_to_jiffies_timeout(to_wait_ms);
226
227 if (time_after(target_jiffies, tmp_jiffies)) {
228 remaining_jiffies = target_jiffies - tmp_jiffies;
229 while (remaining_jiffies)
230 remaining_jiffies =
231 schedule_timeout_uninterruptible(remaining_jiffies);
232 }
233}
234
235/*
236 * __wait_for - magic wait macro
237 *
238 * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
239 * important that we check the condition again after having timed out, since the
240 * timeout could be due to preemption or similar and we've never had a chance to
241 * check the condition before the timeout.
242 */
243#define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
244 const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
245 long wait__ = (Wmin); /* recommended min for usleep is 10 us */ \
246 int ret__; \
247 might_sleep(); \
248 for (;;) { \
249 const bool expired__ = ktime_after(ktime_get_raw(), end__); \
250 OP; \
251 /* Guarantee COND check prior to timeout */ \
252 barrier(); \
253 if (COND) { \
254 ret__ = 0; \
255 break; \
256 } \
257 if (expired__) { \
258 ret__ = -ETIMEDOUT; \
259 break; \
260 } \
261 usleep_range(wait__, wait__ * 2); \
262 if (wait__ < (Wmax)) \
263 wait__ <<= 1; \
264 } \
265 ret__; \
266})
267
268#define _wait_for(COND, US, Wmin, Wmax) __wait_for(, (COND), (US), (Wmin), \
269 (Wmax))
270#define wait_for(COND, MS) _wait_for((COND), (MS) * 1000, 10, 1000)
271
272/* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
273#if IS_ENABLED(CONFIG_DRM_I915_DEBUG) && IS_ENABLED(CONFIG_PREEMPT_COUNT)
274# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
275#else
276# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
277#endif
278
279#define _wait_for_atomic(COND, US, ATOMIC) \
280({ \
281 int cpu, ret, timeout = (US) * 1000; \
282 u64 base; \
283 _WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
284 if (!(ATOMIC)) { \
285 preempt_disable(); \
286 cpu = smp_processor_id(); \
287 } \
288 base = local_clock(); \
289 for (;;) { \
290 u64 now = local_clock(); \
291 if (!(ATOMIC)) \
292 preempt_enable(); \
293 /* Guarantee COND check prior to timeout */ \
294 barrier(); \
295 if (COND) { \
296 ret = 0; \
297 break; \
298 } \
299 if (now - base >= timeout) { \
300 ret = -ETIMEDOUT; \
301 break; \
302 } \
303 cpu_relax(); \
304 if (!(ATOMIC)) { \
305 preempt_disable(); \
306 if (unlikely(cpu != smp_processor_id())) { \
307 timeout -= now - base; \
308 cpu = smp_processor_id(); \
309 base = local_clock(); \
310 } \
311 } \
312 } \
313 ret; \
314})
315
316#define wait_for_us(COND, US) \
317({ \
318 int ret__; \
319 BUILD_BUG_ON(!__builtin_constant_p(US)); \
320 if ((US) > 10) \
321 ret__ = _wait_for((COND), (US), 10, 10); \
322 else \
323 ret__ = _wait_for_atomic((COND), (US), 0); \
324 ret__; \
325})
326
327#define wait_for_atomic_us(COND, US) \
328({ \
329 BUILD_BUG_ON(!__builtin_constant_p(US)); \
330 BUILD_BUG_ON((US) > 50000); \
331 _wait_for_atomic((COND), (US), 1); \
332})
333
334#define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
335
336#define KHz(x) (1000 * (x))
337#define MHz(x) KHz(1000 * (x))
338
339void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
340static inline void __add_taint_for_CI(unsigned int taint)
341{
342 /*
343 * The system is "ok", just about surviving for the user, but
344 * CI results are now unreliable as the HW is very suspect.
345 * CI checks the taint state after every test and will reboot
346 * the machine if the kernel is tainted.
347 */
348 add_taint(taint, LOCKDEP_STILL_OK);
349}
350
351void cancel_timer(struct timer_list *t);
352void set_timer_ms(struct timer_list *t, unsigned long timeout);
353
354static inline bool timer_active(const struct timer_list *t)
355{
356 return READ_ONCE(t->expires);
357}
358
359static inline bool timer_expired(const struct timer_list *t)
360{
361 return timer_active(t) && !timer_pending(t);
362}
363
364static inline bool i915_run_as_guest(void)
365{
366#if IS_ENABLED(CONFIG_X86)
367 return !hypervisor_is_type(X86_HYPER_NATIVE);
368#else
369 /* Not supported yet */
370 return false;
371#endif
372}
373
374bool i915_vtd_active(struct drm_i915_private *i915);
375
376bool i915_direct_stolen_access(struct drm_i915_private *i915);
377
378#endif /* !__I915_UTILS_H */