1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * include/linux/irqflags.h
4  *
5  * IRQ flags tracing: follow the state of the hardirq and softirq flags and
6  * provide callbacks for transitions between ON and OFF states.
7  *
8  * This file gets included from lowlevel asm headers too, to provide
9  * wrapped versions of the local_irq_*() APIs, based on the
10  * raw_local_irq_*() macros from the lowlevel headers.
11  */
12 #ifndef _LINUX_TRACE_IRQFLAGS_H
13 #define _LINUX_TRACE_IRQFLAGS_H
14 
15 #include <linux/typecheck.h>
16 #include <asm/irqflags.h>
17 
18 /* Currently trace_softirqs_on/off is used only by lockdep */
19 #ifdef CONFIG_PROVE_LOCKING
20   extern void trace_softirqs_on(unsigned long ip);
21   extern void trace_softirqs_off(unsigned long ip);
22   extern void lockdep_hardirqs_on(unsigned long ip);
23   extern void lockdep_hardirqs_off(unsigned long ip);
24 #else
trace_softirqs_on(unsigned long ip)25   static inline void trace_softirqs_on(unsigned long ip) { }
trace_softirqs_off(unsigned long ip)26   static inline void trace_softirqs_off(unsigned long ip) { }
lockdep_hardirqs_on(unsigned long ip)27   static inline void lockdep_hardirqs_on(unsigned long ip) { }
lockdep_hardirqs_off(unsigned long ip)28   static inline void lockdep_hardirqs_off(unsigned long ip) { }
29 #endif
30 
31 #ifdef CONFIG_TRACE_IRQFLAGS
32   extern void trace_hardirqs_on(void);
33   extern void trace_hardirqs_off(void);
34 # define trace_hardirq_context(p)	((p)->hardirq_context)
35 # define trace_softirq_context(p)	((p)->softirq_context)
36 # define trace_hardirqs_enabled(p)	((p)->hardirqs_enabled)
37 # define trace_softirqs_enabled(p)	((p)->softirqs_enabled)
38 # define trace_hardirq_enter()			\
39 do {						\
40 	current->hardirq_context++;		\
41 } while (0)
42 # define trace_hardirq_exit()			\
43 do {						\
44 	current->hardirq_context--;		\
45 } while (0)
46 # define lockdep_softirq_enter()		\
47 do {						\
48 	current->softirq_context++;		\
49 } while (0)
50 # define lockdep_softirq_exit()			\
51 do {						\
52 	current->softirq_context--;		\
53 } while (0)
54 #else
55 # define trace_hardirqs_on()		do { } while (0)
56 # define trace_hardirqs_off()		do { } while (0)
57 # define trace_hardirq_context(p)	0
58 # define trace_softirq_context(p)	0
59 # define trace_hardirqs_enabled(p)	0
60 # define trace_softirqs_enabled(p)	0
61 # define trace_hardirq_enter()		do { } while (0)
62 # define trace_hardirq_exit()		do { } while (0)
63 # define lockdep_softirq_enter()	do { } while (0)
64 # define lockdep_softirq_exit()		do { } while (0)
65 #endif
66 
67 #if defined(CONFIG_IRQSOFF_TRACER) || \
68 	defined(CONFIG_PREEMPT_TRACER)
69  extern void stop_critical_timings(void);
70  extern void start_critical_timings(void);
71 #else
72 # define stop_critical_timings() do { } while (0)
73 # define start_critical_timings() do { } while (0)
74 #endif
75 
76 /*
77  * Wrap the arch provided IRQ routines to provide appropriate checks.
78  */
79 #define raw_local_irq_disable()		arch_local_irq_disable()
80 #define raw_local_irq_enable()		arch_local_irq_enable()
81 #define raw_local_irq_save(flags)			\
82 	do {						\
83 		typecheck(unsigned long, flags);	\
84 		flags = arch_local_irq_save();		\
85 	} while (0)
86 #define raw_local_irq_restore(flags)			\
87 	do {						\
88 		typecheck(unsigned long, flags);	\
89 		arch_local_irq_restore(flags);		\
90 	} while (0)
91 #define raw_local_save_flags(flags)			\
92 	do {						\
93 		typecheck(unsigned long, flags);	\
94 		flags = arch_local_save_flags();	\
95 	} while (0)
96 #define raw_irqs_disabled_flags(flags)			\
97 	({						\
98 		typecheck(unsigned long, flags);	\
99 		arch_irqs_disabled_flags(flags);	\
100 	})
101 #define raw_irqs_disabled()		(arch_irqs_disabled())
102 #define raw_safe_halt()			arch_safe_halt()
103 
104 /*
105  * The local_irq_*() APIs are equal to the raw_local_irq*()
106  * if !TRACE_IRQFLAGS.
107  */
108 #ifdef CONFIG_TRACE_IRQFLAGS
109 #define local_irq_enable() \
110 	do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0)
111 #define local_irq_disable() \
112 	do { raw_local_irq_disable(); trace_hardirqs_off(); } while (0)
113 #define local_irq_save(flags)				\
114 	do {						\
115 		raw_local_irq_save(flags);		\
116 		trace_hardirqs_off();			\
117 	} while (0)
118 
119 
120 #define local_irq_restore(flags)			\
121 	do {						\
122 		if (raw_irqs_disabled_flags(flags)) {	\
123 			raw_local_irq_restore(flags);	\
124 			trace_hardirqs_off();		\
125 		} else {				\
126 			trace_hardirqs_on();		\
127 			raw_local_irq_restore(flags);	\
128 		}					\
129 	} while (0)
130 
131 #define safe_halt()				\
132 	do {					\
133 		trace_hardirqs_on();		\
134 		raw_safe_halt();		\
135 	} while (0)
136 
137 
138 #else /* !CONFIG_TRACE_IRQFLAGS */
139 
140 #define local_irq_enable()	do { raw_local_irq_enable(); } while (0)
141 #define local_irq_disable()	do { raw_local_irq_disable(); } while (0)
142 #define local_irq_save(flags)					\
143 	do {							\
144 		raw_local_irq_save(flags);			\
145 	} while (0)
146 #define local_irq_restore(flags) do { raw_local_irq_restore(flags); } while (0)
147 #define safe_halt()		do { raw_safe_halt(); } while (0)
148 
149 #endif /* CONFIG_TRACE_IRQFLAGS */
150 
151 #define local_save_flags(flags)	raw_local_save_flags(flags)
152 
153 /*
154  * Some architectures don't define arch_irqs_disabled(), so even if either
155  * definition would be fine we need to use different ones for the time being
156  * to avoid build issues.
157  */
158 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
159 #define irqs_disabled()					\
160 	({						\
161 		unsigned long _flags;			\
162 		raw_local_save_flags(_flags);		\
163 		raw_irqs_disabled_flags(_flags);	\
164 	})
165 #else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
166 #define irqs_disabled()	raw_irqs_disabled()
167 #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
168 
169 #define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags)
170 
171 #endif
172