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/overflow.h>
29#include <linux/sched.h>
30#include <linux/string_helpers.h>
31#include <linux/types.h>
32#include <linux/workqueue.h>
33#include <linux/sched/clock.h>
34
35#ifdef CONFIG_X86
36#include <asm/hypervisor.h>
37#endif
38
39struct drm_i915_private;
40
41#define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
42 __stringify(x), (long)(x))
43
44#if IS_ENABLED(CONFIG_DRM_I915_DEBUG)
45
46int __i915_inject_probe_error(struct drm_i915_private *i915, int err,
47 const char *func, int line);
48#define i915_inject_probe_error(_i915, _err) \
49 __i915_inject_probe_error((_i915), (_err), __func__, __LINE__)
50bool i915_error_injected(void);
51
52#else
53
54#define i915_inject_probe_error(i915, e) ({ BUILD_BUG_ON_INVALID(i915); 0; })
55#define i915_error_injected() false
56
57#endif
58
59#define i915_inject_probe_failure(i915) i915_inject_probe_error((i915), -ENODEV)
60
61#define i915_probe_error(i915, fmt, ...) ({ \
62 if (i915_error_injected()) \
63 drm_dbg(&(i915)->drm, fmt, ##__VA_ARGS__); \
64 else \
65 drm_err(&(i915)->drm, fmt, ##__VA_ARGS__); \
66})
67
68#define fetch_and_zero(ptr) ({ \
69 typeof(*ptr) __T = *(ptr); \
70 *(ptr) = (typeof(*ptr))0; \
71 __T; \
72})
73
74/*
75 * check_user_mbz: Check that a user value exists and is zero
76 *
77 * Frequently in our uABI we reserve space for future extensions, and
78 * two ensure that userspace is prepared we enforce that space must
79 * be zero. (Then any future extension can safely assume a default value
80 * of 0.)
81 *
82 * check_user_mbz() combines checking that the user pointer is accessible
83 * and that the contained value is zero.
84 *
85 * Returns: -EFAULT if not accessible, -EINVAL if !zero, or 0 on success.
86 */
87#define check_user_mbz(U) ({ \
88 typeof(*(U)) mbz__; \
89 get_user(mbz__, (U)) ? -EFAULT : mbz__ ? -EINVAL : 0; \
90})
91
92#define __mask_next_bit(mask) ({ \
93 int __idx = ffs(mask) - 1; \
94 mask &= ~BIT(__idx); \
95 __idx; \
96})
97
98static inline bool is_power_of_2_u64(u64 n)
99{
100 return (n != 0 && ((n & (n - 1)) == 0));
101}
102
103static inline unsigned long msecs_to_jiffies_timeout(const unsigned int m)
104{
105 unsigned long j = msecs_to_jiffies(m);
106
107 return min_t(unsigned long, MAX_JIFFY_OFFSET, j + 1);
108}
109
110/*
111 * If you need to wait X milliseconds between events A and B, but event B
112 * doesn't happen exactly after event A, you record the timestamp (jiffies) of
113 * when event A happened, then just before event B you call this function and
114 * pass the timestamp as the first argument, and X as the second argument.
115 */
116static inline void
117wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
118{
119 unsigned long target_jiffies, tmp_jiffies, remaining_jiffies;
120
121 /*
122 * Don't re-read the value of "jiffies" every time since it may change
123 * behind our back and break the math.
124 */
125 tmp_jiffies = jiffies;
126 target_jiffies = timestamp_jiffies +
127 msecs_to_jiffies_timeout(m: to_wait_ms);
128
129 if (time_after(target_jiffies, tmp_jiffies)) {
130 remaining_jiffies = target_jiffies - tmp_jiffies;
131 while (remaining_jiffies)
132 remaining_jiffies =
133 schedule_timeout_uninterruptible(timeout: remaining_jiffies);
134 }
135}
136
137#define KHz(x) (1000 * (x))
138#define MHz(x) KHz(1000 * (x))
139
140void add_taint_for_CI(struct drm_i915_private *i915, unsigned int taint);
141static inline void __add_taint_for_CI(unsigned int taint)
142{
143 /*
144 * The system is "ok", just about surviving for the user, but
145 * CI results are now unreliable as the HW is very suspect.
146 * CI checks the taint state after every test and will reboot
147 * the machine if the kernel is tainted.
148 */
149 add_taint(flag: taint, LOCKDEP_STILL_OK);
150}
151
152static inline bool i915_run_as_guest(void)
153{
154#if IS_ENABLED(CONFIG_X86)
155 return !hypervisor_is_type(type: X86_HYPER_NATIVE);
156#else
157 /* Not supported yet */
158 return false;
159#endif
160}
161
162bool i915_vtd_active(struct drm_i915_private *i915);
163
164bool i915_direct_stolen_access(struct drm_i915_private *i915);
165
166#endif /* !__I915_UTILS_H */
167