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://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
 48void __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
 57int __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__)
 61bool 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#define ptr_mask_bits(ptr, n) ({					\
115	unsigned long __v = (unsigned long)(ptr);			\
116	(typeof(ptr))(__v & -BIT(n));					\
117})
118
119#define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
120
121#define ptr_unpack_bits(ptr, bits, n) ({				\
122	unsigned long __v = (unsigned long)(ptr);			\
123	*(bits) = __v & (BIT(n) - 1);					\
124	(typeof(ptr))(__v & -BIT(n));					\
125})
126
127#define ptr_pack_bits(ptr, bits, n) ({					\
128	unsigned long __bits = (bits);					\
129	GEM_BUG_ON(__bits & -BIT(n));					\
130	((typeof(ptr))((unsigned long)(ptr) | __bits));			\
131})
132
133#define ptr_dec(ptr) ({							\
134	unsigned long __v = (unsigned long)(ptr);			\
135	(typeof(ptr))(__v - 1);						\
136})
137
138#define ptr_inc(ptr) ({							\
139	unsigned long __v = (unsigned long)(ptr);			\
140	(typeof(ptr))(__v + 1);						\
141})
142
143#define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
144#define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
145#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
146#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
147
148#define struct_member(T, member) (((T *)0)->member)
149
150#define fetch_and_zero(ptr) ({						\
151	typeof(*ptr) __T = *(ptr);					\
152	*(ptr) = (typeof(*ptr))0;					\
153	__T;								\
154})
155
156static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
157{
158	return a - b;
159}
160
161/*
162 * container_of_user: Extract the superclass from a pointer to a member.
163 *
164 * Exactly like container_of() with the exception that it plays nicely
165 * with sparse for __user @ptr.
166 */
167#define container_of_user(ptr, type, member) ({				\
168	void __user *__mptr = (void __user *)(ptr);			\
169	BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
170			 !__same_type(*(ptr), void),			\
171			 "pointer type mismatch in container_of()");	\
172	((type __user *)(__mptr - offsetof(type, member))); })
173
174/*
175 * check_user_mbz: Check that a user value exists and is zero
176 *
177 * Frequently in our uABI we reserve space for future extensions, and
178 * two ensure that userspace is prepared we enforce that space must
179 * be zero. (Then any future extension can safely assume a default value
180 * of 0.)
181 *
182 * check_user_mbz() combines checking that the user pointer is accessible
183 * and that the contained value is zero.
184 *
185 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
186 */
187#define check_user_mbz(U) ({						\
188	typeof(*(U)) mbz__;						\
189	get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;		\
190})
191
192#define u64_to_ptr(T, x) ({						\
193	typecheck(u64, x);						\
194	(T *)(uintptr_t)(x);						\
195})
196
197#define __mask_next_bit(mask) ({					\
198	int __idx = ffs(mask) - 1;					\
199	mask &= ~BIT(__idx);						\
200	__idx;								\
201})
202
203static inline bool is_power_of_2_u64(u64 n)
204{
205	return (n != 0 && ((n & (n - 1)) == 0));
206}
207
208static inline void __list_del_many(struct list_head *head,
209				   struct list_head *first)
210{
211	first->prev = head;
212	WRITE_ONCE(head->next, first);
213}
214
215static inline int list_is_last_rcu(const struct list_head *list,
216				   const struct list_head *head)
217{
218	return READ_ONCE(list->next) == head;
219}
220
221static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
222{
223	unsigned long j = msecs_to_jiffies(m);
224
225	return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
226}
227
228/*
229 * If you need to wait X milliseconds between events A and B, but event B
230 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
231 * when event A happened, then just before event B you call this function and
232 * pass the timestamp as the first argument, and X as the second argument.
233 */
234static inline void
235wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
236{
237	unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
238
239	/*
240	 * Don't re-read the value of "jiffies" every time since it may change
241	 * behind our back and break the math.
242	 */
243	tmp_jiffies = jiffies;
244	target_jiffies = timestamp_jiffies +
245			 msecs_to_jiffies_timeout(to_wait_ms);
246
247	if (time_after(target_jiffies, tmp_jiffies)) {
248		remaining_jiffies = target_jiffies - tmp_jiffies;
249		while (remaining_jiffies)
250			remaining_jiffies =
251			    schedule_timeout_uninterruptible(remaining_jiffies);
252	}
253}
254
255/**
256 * __wait_for - magic wait macro
257 *
258 * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
259 * important that we check the condition again after having timed out, since the
260 * timeout could be due to preemption or similar and we've never had a chance to
261 * check the condition before the timeout.
262 */
263#define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
264	const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
265	long wait__ = (Wmin); /* recommended min for usleep is 10 us */	\
266	int ret__;							\
267	might_sleep();							\
268	for (;;) {							\
269		const bool expired__ = ktime_after(ktime_get_raw(), end__); \
270		OP;							\
271		/* Guarantee COND check prior to timeout */		\
272		barrier();						\
273		if (COND) {						\
274			ret__ = 0;					\
275			break;						\
276		}							\
277		if (expired__) {					\
278			ret__ = -ETIMEDOUT;				\
279			break;						\
280		}							\
281		usleep_range(wait__, wait__ * 2);			\
282		if (wait__ < (Wmax))					\
283			wait__ <<= 1;					\
284	}								\
285	ret__;								\
286})
287
288#define _wait_for(COND, US, Wmin, Wmax)	__wait_for(, (COND), (US), (Wmin), \
289						   (Wmax))
290#define wait_for(COND, MS)		_wait_for((COND), (MS) * 1000, 10, 1000)
291
292/* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
293#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
294# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
295#else
296# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
297#endif
298
299#define _wait_for_atomic(COND, US, ATOMIC) \
300({ \
301	int cpu, ret, timeout = (US) * 1000; \
302	u64 base; \
303	_WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
304	if (!(ATOMIC)) { \
305		preempt_disable(); \
306		cpu = smp_processor_id(); \
307	} \
308	base = local_clock(); \
309	for (;;) { \
310		u64 now = local_clock(); \
311		if (!(ATOMIC)) \
312			preempt_enable(); \
313		/* Guarantee COND check prior to timeout */ \
314		barrier(); \
315		if (COND) { \
316			ret = 0; \
317			break; \
318		} \
319		if (now - base >= timeout) { \
320			ret = -ETIMEDOUT; \
321			break; \
322		} \
323		cpu_relax(); \
324		if (!(ATOMIC)) { \
325			preempt_disable(); \
326			if (unlikely(cpu != smp_processor_id())) { \
327				timeout -= now - base; \
328				cpu = smp_processor_id(); \
329				base = local_clock(); \
330			} \
331		} \
332	} \
333	ret; \
334})
335
336#define wait_for_us(COND, US) \
337({ \
338	int ret__; \
339	BUILD_BUG_ON(!__builtin_constant_p(US)); \
340	if ((US) > 10) \
341		ret__ = _wait_for((COND), (US), 10, 10); \
342	else \
343		ret__ = _wait_for_atomic((COND), (US), 0); \
344	ret__; \
345})
346
347#define wait_for_atomic_us(COND, US) \
348({ \
349	BUILD_BUG_ON(!__builtin_constant_p(US)); \
350	BUILD_BUG_ON((US) > 50000); \
351	_wait_for_atomic((COND), (US), 1); \
352})
353
354#define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
355
356#define KHz(x) (1000 * (x))
357#define MHz(x) KHz(1000 * (x))
358
359void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
360static inline void __add_taint_for_CI(unsigned int taint)
361{
362	/*
363	 * The system is "ok", just about surviving for the user, but
364	 * CI results are now unreliable as the HW is very suspect.
365	 * CI checks the taint state after every test and will reboot
366	 * the machine if the kernel is tainted.
367	 */
368	add_taint(taint, LOCKDEP_STILL_OK);
369}
370
371void cancel_timer(struct timer_list *t);
372void set_timer_ms(struct timer_list *t, unsigned long timeout);
373
374static inline bool timer_active(const struct timer_list *t)
375{
376	return READ_ONCE(t->expires);
377}
378
379static inline bool timer_expired(const struct timer_list *t)
380{
381	return timer_active(t) && !timer_pending(t);
382}
383
384static inline bool i915_run_as_guest(void)
385{
386#if IS_ENABLED(CONFIG_X86)
387	return !hypervisor_is_type(X86_HYPER_NATIVE);
388#else
389	/* Not supported yet */
390	return false;
391#endif
392}
393
394bool i915_vtd_active(struct drm_i915_private *i915);
395
396#endif /* !__I915_UTILS_H */