xref: /linux/drivers/gpu/drm/i915/i915_utils.h (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
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 #undef WARN_ON
29 /* Many gcc seem to no see through this and fall over :( */
30 #if 0
31 #define WARN_ON(x) ({ \
32 	bool __i915_warn_cond = (x); \
33 	if (__builtin_constant_p(__i915_warn_cond)) \
34 		BUILD_BUG_ON(__i915_warn_cond); \
35 	WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
36 #else
37 #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
38 #endif
39 
40 #undef WARN_ON_ONCE
41 #define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")")
42 
43 #define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
44 			     __stringify(x), (long)(x))
45 
46 #if defined(GCC_VERSION) && GCC_VERSION >= 70000
47 #define add_overflows(A, B) \
48 	__builtin_add_overflow_p((A), (B), (typeof((A) + (B)))0)
49 #else
50 #define add_overflows(A, B) ({ \
51 	typeof(A) a = (A); \
52 	typeof(B) b = (B); \
53 	a + b < a; \
54 })
55 #endif
56 
57 #define range_overflows(start, size, max) ({ \
58 	typeof(start) start__ = (start); \
59 	typeof(size) size__ = (size); \
60 	typeof(max) max__ = (max); \
61 	(void)(&start__ == &size__); \
62 	(void)(&start__ == &max__); \
63 	start__ > max__ || size__ > max__ - start__; \
64 })
65 
66 #define range_overflows_t(type, start, size, max) \
67 	range_overflows((type)(start), (type)(size), (type)(max))
68 
69 /* Note we don't consider signbits :| */
70 #define overflows_type(x, T) \
71 	(sizeof(x) > sizeof(T) && (x) >> (sizeof(T) * BITS_PER_BYTE))
72 
73 #define ptr_mask_bits(ptr, n) ({					\
74 	unsigned long __v = (unsigned long)(ptr);			\
75 	(typeof(ptr))(__v & -BIT(n));					\
76 })
77 
78 #define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
79 
80 #define ptr_unpack_bits(ptr, bits, n) ({				\
81 	unsigned long __v = (unsigned long)(ptr);			\
82 	*(bits) = __v & (BIT(n) - 1);					\
83 	(typeof(ptr))(__v & -BIT(n));					\
84 })
85 
86 #define ptr_pack_bits(ptr, bits, n) ({					\
87 	unsigned long __bits = (bits);					\
88 	GEM_BUG_ON(__bits & -BIT(n));					\
89 	((typeof(ptr))((unsigned long)(ptr) | __bits));			\
90 })
91 
92 #define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
93 #define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
94 #define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
95 #define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
96 
97 #define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
98 
99 #define fetch_and_zero(ptr) ({						\
100 	typeof(*ptr) __T = *(ptr);					\
101 	*(ptr) = (typeof(*ptr))0;					\
102 	__T;								\
103 })
104 
105 static inline u64 ptr_to_u64(const void *ptr)
106 {
107 	return (uintptr_t)ptr;
108 }
109 
110 #define u64_to_ptr(T, x) ({						\
111 	typecheck(u64, x);						\
112 	(T *)(uintptr_t)(x);						\
113 })
114 
115 #define __mask_next_bit(mask) ({					\
116 	int __idx = ffs(mask) - 1;					\
117 	mask &= ~BIT(__idx);						\
118 	__idx;								\
119 })
120 
121 #include <linux/list.h>
122 
123 static inline int list_is_first(const struct list_head *list,
124 				const struct list_head *head)
125 {
126 	return head->next == list;
127 }
128 
129 static inline void __list_del_many(struct list_head *head,
130 				   struct list_head *first)
131 {
132 	first->prev = head;
133 	WRITE_ONCE(head->next, first);
134 }
135 
136 /*
137  * Wait until the work is finally complete, even if it tries to postpone
138  * by requeueing itself. Note, that if the worker never cancels itself,
139  * we will spin forever.
140  */
141 static inline void drain_delayed_work(struct delayed_work *dw)
142 {
143 	do {
144 		while (flush_delayed_work(dw))
145 			;
146 	} while (delayed_work_pending(dw));
147 }
148 
149 static inline const char *yesno(bool v)
150 {
151 	return v ? "yes" : "no";
152 }
153 
154 static inline const char *onoff(bool v)
155 {
156 	return v ? "on" : "off";
157 }
158 
159 static inline const char *enableddisabled(bool v)
160 {
161 	return v ? "enabled" : "disabled";
162 }
163 
164 #endif /* !__I915_UTILS_H */
165