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/types.h>
 32#include <linux/workqueue.h>
 33
 34struct drm_i915_private;
 35
 36#undef WARN_ON
 37/* Many gcc seem to no see through this and fall over :( */
 38#if 0
 39#define WARN_ON(x) ({ \
 40	bool __i915_warn_cond = (x); \
 41	if (__builtin_constant_p(__i915_warn_cond)) \
 42		BUILD_BUG_ON(__i915_warn_cond); \
 43	WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
 44#else
 45#define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
 46#endif
 47
 48#undef WARN_ON_ONCE
 49#define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")")
 50
 51#define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
 52			     __stringify(x), (long)(x))
 53
 54void __printf(3, 4)
 55__i915_printk(struct drm_i915_private *dev_priv, const char *level,
 56	      const char *fmt, ...);
 57
 58#define i915_report_error(dev_priv, fmt, ...)				   \
 59	__i915_printk(dev_priv, KERN_ERR, fmt, ##__VA_ARGS__)
 60
 61#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
 62
 63int __i915_inject_load_error(struct drm_i915_private *i915, int err,
 64			     const char *func, int line);
 65#define i915_inject_load_error(_i915, _err) \
 66	__i915_inject_load_error((_i915), (_err), __func__, __LINE__)
 67bool i915_error_injected(void);
 68
 69#else
 70
 71#define i915_inject_load_error(_i915, _err) 0
 72#define i915_error_injected() false
 73
 74#endif
 75
 76#define i915_inject_probe_failure(i915) i915_inject_load_error((i915), -ENODEV)
 77
 78#define i915_probe_error(i915, fmt, ...)				   \
 79	__i915_printk(i915, i915_error_injected() ? KERN_DEBUG : KERN_ERR, \
 80		      fmt, ##__VA_ARGS__)
 81
 82#if defined(GCC_VERSION) && GCC_VERSION >= 70000
 83#define add_overflows_t(T, A, B) \
 84	__builtin_add_overflow_p((A), (B), (T)0)
 85#else
 86#define add_overflows_t(T, A, B) ({ \
 87	typeof(A) a = (A); \
 88	typeof(B) b = (B); \
 89	(T)(a + b) < a; \
 90})
 91#endif
 92
 93#define add_overflows(A, B) \
 94	add_overflows_t(typeof((A) + (B)), (A), (B))
 95
 96#define range_overflows(start, size, max) ({ \
 97	typeof(start) start__ = (start); \
 98	typeof(size) size__ = (size); \
 99	typeof(max) max__ = (max); \
100	(void)(&start__ == &size__); \
101	(void)(&start__ == &max__); \
102	start__ > max__ || size__ > max__ - start__; \
103})
104
105#define range_overflows_t(type, start, size, max) \
106	range_overflows((type)(start), (type)(size), (type)(max))
107
108/* Note we don't consider signbits :| */
109#define overflows_type(x, T) \
110	(sizeof(x) > sizeof(T) && (x) >> BITS_PER_TYPE(T))
111
112static inline bool
113__check_struct_size(size_t base, size_t arr, size_t count, size_t *size)
114{
115	size_t sz;
116
117	if (check_mul_overflow(count, arr, &sz))
118		return false;
119
120	if (check_add_overflow(sz, base, &sz))
121		return false;
122
123	*size = sz;
124	return true;
125}
126
127/**
128 * check_struct_size() - Calculate size of structure with trailing array.
129 * @p: Pointer to the structure.
130 * @member: Name of the array member.
131 * @n: Number of elements in the array.
132 * @sz: Total size of structure and array
133 *
134 * Calculates size of memory needed for structure @p followed by an
135 * array of @n @member elements, like struct_size() but reports
136 * whether it overflowed, and the resultant size in @sz
137 *
138 * Return: false if the calculation overflowed.
139 */
140#define check_struct_size(p, member, n, sz) \
141	likely(__check_struct_size(sizeof(*(p)), \
142				   sizeof(*(p)->member) + __must_be_array((p)->member), \
143				   n, sz))
144
145#define ptr_mask_bits(ptr, n) ({					\
146	unsigned long __v = (unsigned long)(ptr);			\
147	(typeof(ptr))(__v & -BIT(n));					\
148})
149
150#define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
151
152#define ptr_unpack_bits(ptr, bits, n) ({				\
153	unsigned long __v = (unsigned long)(ptr);			\
154	*(bits) = __v & (BIT(n) - 1);					\
155	(typeof(ptr))(__v & -BIT(n));					\
156})
157
158#define ptr_pack_bits(ptr, bits, n) ({					\
159	unsigned long __bits = (bits);					\
160	GEM_BUG_ON(__bits & -BIT(n));					\
161	((typeof(ptr))((unsigned long)(ptr) | __bits));			\
162})
163
164#define ptr_dec(ptr) ({							\
165	unsigned long __v = (unsigned long)(ptr);			\
166	(typeof(ptr))(__v - 1);						\
167})
168
169#define ptr_inc(ptr) ({							\
170	unsigned long __v = (unsigned long)(ptr);			\
171	(typeof(ptr))(__v + 1);						\
172})
173
174#define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
175#define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
176#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
177#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
178
179#define struct_member(T, member) (((T *)0)->member)
180
181#define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
182
183#define fetch_and_zero(ptr) ({						\
184	typeof(*ptr) __T = *(ptr);					\
185	*(ptr) = (typeof(*ptr))0;					\
186	__T;								\
187})
188
189/*
190 * container_of_user: Extract the superclass from a pointer to a member.
191 *
192 * Exactly like container_of() with the exception that it plays nicely
193 * with sparse for __user @ptr.
194 */
195#define container_of_user(ptr, type, member) ({				\
196	void __user *__mptr = (void __user *)(ptr);			\
197	BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
198			 !__same_type(*(ptr), void),			\
199			 "pointer type mismatch in container_of()");	\
200	((type __user *)(__mptr - offsetof(type, member))); })
201
202/*
203 * check_user_mbz: Check that a user value exists and is zero
204 *
205 * Frequently in our uABI we reserve space for future extensions, and
206 * two ensure that userspace is prepared we enforce that space must
207 * be zero. (Then any future extension can safely assume a default value
208 * of 0.)
209 *
210 * check_user_mbz() combines checking that the user pointer is accessible
211 * and that the contained value is zero.
212 *
213 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
214 */
215#define check_user_mbz(U) ({						\
216	typeof(*(U)) mbz__;						\
217	get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0;		\
218})
219
220static inline u64 ptr_to_u64(const void *ptr)
221{
222	return (uintptr_t)ptr;
223}
224
225#define u64_to_ptr(T, x) ({						\
226	typecheck(u64, x);						\
227	(T *)(uintptr_t)(x);						\
228})
229
230#define __mask_next_bit(mask) ({					\
231	int __idx = ffs(mask) - 1;					\
232	mask &= ~BIT(__idx);						\
233	__idx;								\
234})
235
236static inline void __list_del_many(struct list_head *head,
237				   struct list_head *first)
238{
239	first->prev = head;
240	WRITE_ONCE(head->next, first);
241}
242
243/*
244 * Wait until the work is finally complete, even if it tries to postpone
245 * by requeueing itself. Note, that if the worker never cancels itself,
246 * we will spin forever.
247 */
248static inline void drain_delayed_work(struct delayed_work *dw)
249{
250	do {
251		while (flush_delayed_work(dw))
252			;
253	} while (delayed_work_pending(dw));
254}
255
256static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
257{
258	unsigned long j = msecs_to_jiffies(m);
259
260	return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
261}
262
263/*
264 * If you need to wait X milliseconds between events A and B, but event B
265 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
266 * when event A happened, then just before event B you call this function and
267 * pass the timestamp as the first argument, and X as the second argument.
268 */
269static inline void
270wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
271{
272	unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
273
274	/*
275	 * Don't re-read the value of "jiffies" every time since it may change
276	 * behind our back and break the math.
277	 */
278	tmp_jiffies = jiffies;
279	target_jiffies = timestamp_jiffies +
280			 msecs_to_jiffies_timeout(to_wait_ms);
281
282	if (time_after(target_jiffies, tmp_jiffies)) {
283		remaining_jiffies = target_jiffies - tmp_jiffies;
284		while (remaining_jiffies)
285			remaining_jiffies =
286			    schedule_timeout_uninterruptible(remaining_jiffies);
287	}
288}
289
290/**
291 * __wait_for - magic wait macro
292 *
293 * Macro to help avoid open coding check/wait/timeout patterns. Note that it's
294 * important that we check the condition again after having timed out, since the
295 * timeout could be due to preemption or similar and we've never had a chance to
296 * check the condition before the timeout.
297 */
298#define __wait_for(OP, COND, US, Wmin, Wmax) ({ \
299	const ktime_t end__ = ktime_add_ns(ktime_get_raw(), 1000ll * (US)); \
300	long wait__ = (Wmin); /* recommended min for usleep is 10 us */	\
301	int ret__;							\
302	might_sleep();							\
303	for (;;) {							\
304		const bool expired__ = ktime_after(ktime_get_raw(), end__); \
305		OP;							\
306		/* Guarantee COND check prior to timeout */		\
307		barrier();						\
308		if (COND) {						\
309			ret__ = 0;					\
310			break;						\
311		}							\
312		if (expired__) {					\
313			ret__ = -ETIMEDOUT;				\
314			break;						\
315		}							\
316		usleep_range(wait__, wait__ * 2);			\
317		if (wait__ < (Wmax))					\
318			wait__ <<= 1;					\
319	}								\
320	ret__;								\
321})
322
323#define _wait_for(COND, US, Wmin, Wmax)	__wait_for(, (COND), (US), (Wmin), \
324						   (Wmax))
325#define wait_for(COND, MS)		_wait_for((COND), (MS) * 1000, 10, 1000)
326
327/* If CONFIG_PREEMPT_COUNT is disabled, in_atomic() always reports false. */
328#if defined(CONFIG_DRM_I915_DEBUG) && defined(CONFIG_PREEMPT_COUNT)
329# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) WARN_ON_ONCE((ATOMIC) && !in_atomic())
330#else
331# define _WAIT_FOR_ATOMIC_CHECK(ATOMIC) do { } while (0)
332#endif
333
334#define _wait_for_atomic(COND, US, ATOMIC) \
335({ \
336	int cpu, ret, timeout = (US) * 1000; \
337	u64 base; \
338	_WAIT_FOR_ATOMIC_CHECK(ATOMIC); \
339	if (!(ATOMIC)) { \
340		preempt_disable(); \
341		cpu = smp_processor_id(); \
342	} \
343	base = local_clock(); \
344	for (;;) { \
345		u64 now = local_clock(); \
346		if (!(ATOMIC)) \
347			preempt_enable(); \
348		/* Guarantee COND check prior to timeout */ \
349		barrier(); \
350		if (COND) { \
351			ret = 0; \
352			break; \
353		} \
354		if (now - base >= timeout) { \
355			ret = -ETIMEDOUT; \
356			break; \
357		} \
358		cpu_relax(); \
359		if (!(ATOMIC)) { \
360			preempt_disable(); \
361			if (unlikely(cpu != smp_processor_id())) { \
362				timeout -= now - base; \
363				cpu = smp_processor_id(); \
364				base = local_clock(); \
365			} \
366		} \
367	} \
368	ret; \
369})
370
371#define wait_for_us(COND, US) \
372({ \
373	int ret__; \
374	BUILD_BUG_ON(!__builtin_constant_p(US)); \
375	if ((US) > 10) \
376		ret__ = _wait_for((COND), (US), 10, 10); \
377	else \
378		ret__ = _wait_for_atomic((COND), (US), 0); \
379	ret__; \
380})
381
382#define wait_for_atomic_us(COND, US) \
383({ \
384	BUILD_BUG_ON(!__builtin_constant_p(US)); \
385	BUILD_BUG_ON((US) > 50000); \
386	_wait_for_atomic((COND), (US), 1); \
387})
388
389#define wait_for_atomic(COND, MS) wait_for_atomic_us((COND), (MS) * 1000)
390
391#define KHz(x) (1000 * (x))
392#define MHz(x) KHz(1000 * (x))
393
394#define KBps(x) (1000 * (x))
395#define MBps(x) KBps(1000 * (x))
396#define GBps(x) ((u64)1000 * MBps((x)))
397
398static inline const char *yesno(bool v)
399{
400	return v ? "yes" : "no";
401}
402
403static inline const char *onoff(bool v)
404{
405	return v ? "on" : "off";
406}
407
408static inline const char *enableddisabled(bool v)
409{
410	return v ? "enabled" : "disabled";
411}
412
413static inline void add_taint_for_CI(unsigned int taint)
414{
415	/*
416	 * The system is "ok", just about surviving for the user, but
417	 * CI results are now unreliable as the HW is very suspect.
418	 * CI checks the taint state after every test and will reboot
419	 * the machine if the kernel is tainted.
420	 */
421	add_taint(taint, LOCKDEP_STILL_OK);
422}
423
424#endif /* !__I915_UTILS_H */