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 #include <asm/percpu.h>
18 
19 /* Currently lockdep_softirqs_on/off is used only by lockdep */
20 #ifdef CONFIG_PROVE_LOCKING
21   extern void lockdep_softirqs_on(unsigned long ip);
22   extern void lockdep_softirqs_off(unsigned long ip);
23   extern void lockdep_hardirqs_on_prepare(void);
24   extern void lockdep_hardirqs_on(unsigned long ip);
25   extern void lockdep_hardirqs_off(unsigned long ip);
26 #else
lockdep_softirqs_on(unsigned long ip)27   static inline void lockdep_softirqs_on(unsigned long ip) { }
lockdep_softirqs_off(unsigned long ip)28   static inline void lockdep_softirqs_off(unsigned long ip) { }
lockdep_hardirqs_on_prepare(void)29   static inline void lockdep_hardirqs_on_prepare(void) { }
lockdep_hardirqs_on(unsigned long ip)30   static inline void lockdep_hardirqs_on(unsigned long ip) { }
lockdep_hardirqs_off(unsigned long ip)31   static inline void lockdep_hardirqs_off(unsigned long ip) { }
32 #endif
33 
34 #ifdef CONFIG_TRACE_IRQFLAGS
35 
36 /* Per-task IRQ trace events information. */
37 struct irqtrace_events {
38 	unsigned int	irq_events;
39 	unsigned long	hardirq_enable_ip;
40 	unsigned long	hardirq_disable_ip;
41 	unsigned int	hardirq_enable_event;
42 	unsigned int	hardirq_disable_event;
43 	unsigned long	softirq_disable_ip;
44 	unsigned long	softirq_enable_ip;
45 	unsigned int	softirq_disable_event;
46 	unsigned int	softirq_enable_event;
47 };
48 
49 DECLARE_PER_CPU(int, hardirqs_enabled);
50 DECLARE_PER_CPU(int, hardirq_context);
51 
52 extern void trace_hardirqs_on_prepare(void);
53 extern void trace_hardirqs_off_finish(void);
54 extern void trace_hardirqs_on(void);
55 extern void trace_hardirqs_off(void);
56 
57 # define lockdep_hardirq_context()	(raw_cpu_read(hardirq_context))
58 # define lockdep_softirq_context(p)	((p)->softirq_context)
59 # define lockdep_hardirqs_enabled()	(this_cpu_read(hardirqs_enabled))
60 # define lockdep_softirqs_enabled(p)	((p)->softirqs_enabled)
61 # define lockdep_hardirq_enter()			\
62 do {							\
63 	if (__this_cpu_inc_return(hardirq_context) == 1)\
64 		current->hardirq_threaded = 0;		\
65 } while (0)
66 # define lockdep_hardirq_threaded()		\
67 do {						\
68 	current->hardirq_threaded = 1;		\
69 } while (0)
70 # define lockdep_hardirq_exit()			\
71 do {						\
72 	__this_cpu_dec(hardirq_context);	\
73 } while (0)
74 
75 # define lockdep_hrtimer_enter(__hrtimer)		\
76 ({							\
77 	bool __expires_hardirq = true;			\
78 							\
79 	if (!__hrtimer->is_hard) {			\
80 		current->irq_config = 1;		\
81 		__expires_hardirq = false;		\
82 	}						\
83 	__expires_hardirq;				\
84 })
85 
86 # define lockdep_hrtimer_exit(__expires_hardirq)	\
87 	do {						\
88 		if (!__expires_hardirq)			\
89 			current->irq_config = 0;	\
90 	} while (0)
91 
92 # define lockdep_posixtimer_enter()				\
93 	  do {							\
94 		  current->irq_config = 1;			\
95 	  } while (0)
96 
97 # define lockdep_posixtimer_exit()				\
98 	  do {							\
99 		  current->irq_config = 0;			\
100 	  } while (0)
101 
102 # define lockdep_irq_work_enter(_flags)					\
103 	  do {								\
104 		  if (!((_flags) & IRQ_WORK_HARD_IRQ))			\
105 			current->irq_config = 1;			\
106 	  } while (0)
107 # define lockdep_irq_work_exit(_flags)					\
108 	  do {								\
109 		  if (!((_flags) & IRQ_WORK_HARD_IRQ))			\
110 			current->irq_config = 0;			\
111 	  } while (0)
112 
113 #else
114 # define trace_hardirqs_on_prepare()		do { } while (0)
115 # define trace_hardirqs_off_finish()		do { } while (0)
116 # define trace_hardirqs_on()			do { } while (0)
117 # define trace_hardirqs_off()			do { } while (0)
118 # define lockdep_hardirq_context()		0
119 # define lockdep_softirq_context(p)		0
120 # define lockdep_hardirqs_enabled()		0
121 # define lockdep_softirqs_enabled(p)		0
122 # define lockdep_hardirq_enter()		do { } while (0)
123 # define lockdep_hardirq_threaded()		do { } while (0)
124 # define lockdep_hardirq_exit()			do { } while (0)
125 # define lockdep_softirq_enter()		do { } while (0)
126 # define lockdep_softirq_exit()			do { } while (0)
127 # define lockdep_hrtimer_enter(__hrtimer)	false
128 # define lockdep_hrtimer_exit(__context)	do { } while (0)
129 # define lockdep_posixtimer_enter()		do { } while (0)
130 # define lockdep_posixtimer_exit()		do { } while (0)
131 # define lockdep_irq_work_enter(__work)		do { } while (0)
132 # define lockdep_irq_work_exit(__work)		do { } while (0)
133 #endif
134 
135 #if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT)
136 # define lockdep_softirq_enter()		\
137 do {						\
138 	current->softirq_context++;		\
139 } while (0)
140 # define lockdep_softirq_exit()			\
141 do {						\
142 	current->softirq_context--;		\
143 } while (0)
144 
145 #else
146 # define lockdep_softirq_enter()		do { } while (0)
147 # define lockdep_softirq_exit()			do { } while (0)
148 #endif
149 
150 #if defined(CONFIG_IRQSOFF_TRACER) || \
151 	defined(CONFIG_PREEMPT_TRACER)
152  extern void stop_critical_timings(void);
153  extern void start_critical_timings(void);
154 #else
155 # define stop_critical_timings() do { } while (0)
156 # define start_critical_timings() do { } while (0)
157 #endif
158 
159 #ifdef CONFIG_DEBUG_IRQFLAGS
160 extern void warn_bogus_irq_restore(void);
161 #define raw_check_bogus_irq_restore()			\
162 	do {						\
163 		if (unlikely(!arch_irqs_disabled()))	\
164 			warn_bogus_irq_restore();	\
165 	} while (0)
166 #else
167 #define raw_check_bogus_irq_restore() do { } while (0)
168 #endif
169 
170 /*
171  * Wrap the arch provided IRQ routines to provide appropriate checks.
172  */
173 #define raw_local_irq_disable()		arch_local_irq_disable()
174 #define raw_local_irq_enable()		arch_local_irq_enable()
175 #define raw_local_irq_save(flags)			\
176 	do {						\
177 		typecheck(unsigned long, flags);	\
178 		flags = arch_local_irq_save();		\
179 	} while (0)
180 #define raw_local_irq_restore(flags)			\
181 	do {						\
182 		typecheck(unsigned long, flags);	\
183 		raw_check_bogus_irq_restore();		\
184 		arch_local_irq_restore(flags);		\
185 	} while (0)
186 #define raw_local_save_flags(flags)			\
187 	do {						\
188 		typecheck(unsigned long, flags);	\
189 		flags = arch_local_save_flags();	\
190 	} while (0)
191 #define raw_irqs_disabled_flags(flags)			\
192 	({						\
193 		typecheck(unsigned long, flags);	\
194 		arch_irqs_disabled_flags(flags);	\
195 	})
196 #define raw_irqs_disabled()		(arch_irqs_disabled())
197 #define raw_safe_halt()			arch_safe_halt()
198 
199 /*
200  * The local_irq_*() APIs are equal to the raw_local_irq*()
201  * if !TRACE_IRQFLAGS.
202  */
203 #ifdef CONFIG_TRACE_IRQFLAGS
204 
205 #define local_irq_enable()				\
206 	do {						\
207 		trace_hardirqs_on();			\
208 		raw_local_irq_enable();			\
209 	} while (0)
210 
211 #define local_irq_disable()				\
212 	do {						\
213 		bool was_disabled = raw_irqs_disabled();\
214 		raw_local_irq_disable();		\
215 		if (!was_disabled)			\
216 			trace_hardirqs_off();		\
217 	} while (0)
218 
219 #define local_irq_save(flags)				\
220 	do {						\
221 		raw_local_irq_save(flags);		\
222 		if (!raw_irqs_disabled_flags(flags))	\
223 			trace_hardirqs_off();		\
224 	} while (0)
225 
226 #define local_irq_restore(flags)			\
227 	do {						\
228 		if (!raw_irqs_disabled_flags(flags))	\
229 			trace_hardirqs_on();		\
230 		raw_local_irq_restore(flags);		\
231 	} while (0)
232 
233 #define safe_halt()				\
234 	do {					\
235 		trace_hardirqs_on();		\
236 		raw_safe_halt();		\
237 	} while (0)
238 
239 
240 #else /* !CONFIG_TRACE_IRQFLAGS */
241 
242 #define local_irq_enable()	do { raw_local_irq_enable(); } while (0)
243 #define local_irq_disable()	do { raw_local_irq_disable(); } while (0)
244 #define local_irq_save(flags)	do { raw_local_irq_save(flags); } while (0)
245 #define local_irq_restore(flags) do { raw_local_irq_restore(flags); } while (0)
246 #define safe_halt()		do { raw_safe_halt(); } while (0)
247 
248 #endif /* CONFIG_TRACE_IRQFLAGS */
249 
250 #define local_save_flags(flags)	raw_local_save_flags(flags)
251 
252 /*
253  * Some architectures don't define arch_irqs_disabled(), so even if either
254  * definition would be fine we need to use different ones for the time being
255  * to avoid build issues.
256  */
257 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
258 #define irqs_disabled()					\
259 	({						\
260 		unsigned long _flags;			\
261 		raw_local_save_flags(_flags);		\
262 		raw_irqs_disabled_flags(_flags);	\
263 	})
264 #else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
265 #define irqs_disabled()	raw_irqs_disabled()
266 #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
267 
268 #define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags)
269 
270 #endif
271