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/irqflags_types.h>
16 #include <linux/typecheck.h>
17 #include <linux/cleanup.h>
18 #include <asm/irqflags.h>
19 #include <asm/percpu.h>
20 
21 /* Currently lockdep_softirqs_on/off is used only by lockdep */
22 #ifdef CONFIG_PROVE_LOCKING
23   extern void lockdep_softirqs_on(unsigned long ip);
24   extern void lockdep_softirqs_off(unsigned long ip);
25   extern void lockdep_hardirqs_on_prepare(void);
26   extern void lockdep_hardirqs_on(unsigned long ip);
27   extern void lockdep_hardirqs_off(unsigned long ip);
28 #else
lockdep_softirqs_on(unsigned long ip)29   static inline void lockdep_softirqs_on(unsigned long ip) { }
lockdep_softirqs_off(unsigned long ip)30   static inline void lockdep_softirqs_off(unsigned long ip) { }
lockdep_hardirqs_on_prepare(void)31   static inline void lockdep_hardirqs_on_prepare(void) { }
lockdep_hardirqs_on(unsigned long ip)32   static inline void lockdep_hardirqs_on(unsigned long ip) { }
lockdep_hardirqs_off(unsigned long ip)33   static inline void lockdep_hardirqs_off(unsigned long ip) { }
34 #endif
35 
36 #ifdef CONFIG_TRACE_IRQFLAGS
37 
38 DECLARE_PER_CPU(int, hardirqs_enabled);
39 DECLARE_PER_CPU(int, hardirq_context);
40 
41 extern void trace_hardirqs_on_prepare(void);
42 extern void trace_hardirqs_off_finish(void);
43 extern void trace_hardirqs_on(void);
44 extern void trace_hardirqs_off(void);
45 
46 # define lockdep_hardirq_context()	(raw_cpu_read(hardirq_context))
47 # define lockdep_softirq_context(p)	((p)->softirq_context)
48 # define lockdep_hardirqs_enabled()	(this_cpu_read(hardirqs_enabled))
49 # define lockdep_softirqs_enabled(p)	((p)->softirqs_enabled)
50 # define lockdep_hardirq_enter()			\
51 do {							\
52 	if (__this_cpu_inc_return(hardirq_context) == 1)\
53 		current->hardirq_threaded = 0;		\
54 } while (0)
55 # define lockdep_hardirq_threaded()		\
56 do {						\
57 	current->hardirq_threaded = 1;		\
58 } while (0)
59 # define lockdep_hardirq_exit()			\
60 do {						\
61 	__this_cpu_dec(hardirq_context);	\
62 } while (0)
63 
64 # define lockdep_hrtimer_enter(__hrtimer)		\
65 ({							\
66 	bool __expires_hardirq = true;			\
67 							\
68 	if (!__hrtimer->is_hard) {			\
69 		current->irq_config = 1;		\
70 		__expires_hardirq = false;		\
71 	}						\
72 	__expires_hardirq;				\
73 })
74 
75 # define lockdep_hrtimer_exit(__expires_hardirq)	\
76 	do {						\
77 		if (!__expires_hardirq)			\
78 			current->irq_config = 0;	\
79 	} while (0)
80 
81 # define lockdep_posixtimer_enter()				\
82 	  do {							\
83 		  current->irq_config = 1;			\
84 	  } while (0)
85 
86 # define lockdep_posixtimer_exit()				\
87 	  do {							\
88 		  current->irq_config = 0;			\
89 	  } while (0)
90 
91 # define lockdep_irq_work_enter(_flags)					\
92 	  do {								\
93 		  if (!((_flags) & IRQ_WORK_HARD_IRQ))			\
94 			current->irq_config = 1;			\
95 	  } while (0)
96 # define lockdep_irq_work_exit(_flags)					\
97 	  do {								\
98 		  if (!((_flags) & IRQ_WORK_HARD_IRQ))			\
99 			current->irq_config = 0;			\
100 	  } while (0)
101 
102 #else
103 # define trace_hardirqs_on_prepare()		do { } while (0)
104 # define trace_hardirqs_off_finish()		do { } while (0)
105 # define trace_hardirqs_on()			do { } while (0)
106 # define trace_hardirqs_off()			do { } while (0)
107 # define lockdep_hardirq_context()		0
108 # define lockdep_softirq_context(p)		0
109 # define lockdep_hardirqs_enabled()		0
110 # define lockdep_softirqs_enabled(p)		0
111 # define lockdep_hardirq_enter()		do { } while (0)
112 # define lockdep_hardirq_threaded()		do { } while (0)
113 # define lockdep_hardirq_exit()			do { } while (0)
114 # define lockdep_softirq_enter()		do { } while (0)
115 # define lockdep_softirq_exit()			do { } while (0)
116 # define lockdep_hrtimer_enter(__hrtimer)	false
117 # define lockdep_hrtimer_exit(__context)	do { (void)(__context); } while (0)
118 # define lockdep_posixtimer_enter()		do { } while (0)
119 # define lockdep_posixtimer_exit()		do { } while (0)
120 # define lockdep_irq_work_enter(__work)		do { } while (0)
121 # define lockdep_irq_work_exit(__work)		do { } while (0)
122 #endif
123 
124 #if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT)
125 # define lockdep_softirq_enter()		\
126 do {						\
127 	current->softirq_context++;		\
128 } while (0)
129 # define lockdep_softirq_exit()			\
130 do {						\
131 	current->softirq_context--;		\
132 } while (0)
133 
134 #else
135 # define lockdep_softirq_enter()		do { } while (0)
136 # define lockdep_softirq_exit()			do { } while (0)
137 #endif
138 
139 #if defined(CONFIG_IRQSOFF_TRACER) || \
140 	defined(CONFIG_PREEMPT_TRACER)
141  extern void stop_critical_timings(void);
142  extern void start_critical_timings(void);
143 #else
144 # define stop_critical_timings() do { } while (0)
145 # define start_critical_timings() do { } while (0)
146 #endif
147 
148 #ifdef CONFIG_DEBUG_IRQFLAGS
149 extern void warn_bogus_irq_restore(void);
150 #define raw_check_bogus_irq_restore()			\
151 	do {						\
152 		if (unlikely(!arch_irqs_disabled()))	\
153 			warn_bogus_irq_restore();	\
154 	} while (0)
155 #else
156 #define raw_check_bogus_irq_restore() do { } while (0)
157 #endif
158 
159 /*
160  * Wrap the arch provided IRQ routines to provide appropriate checks.
161  */
162 #define raw_local_irq_disable()		arch_local_irq_disable()
163 #define raw_local_irq_enable()		arch_local_irq_enable()
164 #define raw_local_irq_save(flags)			\
165 	do {						\
166 		typecheck(unsigned long, flags);	\
167 		flags = arch_local_irq_save();		\
168 	} while (0)
169 #define raw_local_irq_restore(flags)			\
170 	do {						\
171 		typecheck(unsigned long, flags);	\
172 		raw_check_bogus_irq_restore();		\
173 		arch_local_irq_restore(flags);		\
174 	} while (0)
175 #define raw_local_save_flags(flags)			\
176 	do {						\
177 		typecheck(unsigned long, flags);	\
178 		flags = arch_local_save_flags();	\
179 	} while (0)
180 #define raw_irqs_disabled_flags(flags)			\
181 	({						\
182 		typecheck(unsigned long, flags);	\
183 		arch_irqs_disabled_flags(flags);	\
184 	})
185 #define raw_irqs_disabled()		(arch_irqs_disabled())
186 #define raw_safe_halt()			arch_safe_halt()
187 
188 /*
189  * The local_irq_*() APIs are equal to the raw_local_irq*()
190  * if !TRACE_IRQFLAGS.
191  */
192 #ifdef CONFIG_TRACE_IRQFLAGS
193 
194 #define local_irq_enable()				\
195 	do {						\
196 		trace_hardirqs_on();			\
197 		raw_local_irq_enable();			\
198 	} while (0)
199 
200 #define local_irq_disable()				\
201 	do {						\
202 		bool was_disabled = raw_irqs_disabled();\
203 		raw_local_irq_disable();		\
204 		if (!was_disabled)			\
205 			trace_hardirqs_off();		\
206 	} while (0)
207 
208 #define local_irq_save(flags)				\
209 	do {						\
210 		raw_local_irq_save(flags);		\
211 		if (!raw_irqs_disabled_flags(flags))	\
212 			trace_hardirqs_off();		\
213 	} while (0)
214 
215 #define local_irq_restore(flags)			\
216 	do {						\
217 		if (!raw_irqs_disabled_flags(flags))	\
218 			trace_hardirqs_on();		\
219 		raw_local_irq_restore(flags);		\
220 	} while (0)
221 
222 #define safe_halt()				\
223 	do {					\
224 		trace_hardirqs_on();		\
225 		raw_safe_halt();		\
226 	} while (0)
227 
228 
229 #else /* !CONFIG_TRACE_IRQFLAGS */
230 
231 #define local_irq_enable()	do { raw_local_irq_enable(); } while (0)
232 #define local_irq_disable()	do { raw_local_irq_disable(); } while (0)
233 #define local_irq_save(flags)	do { raw_local_irq_save(flags); } while (0)
234 #define local_irq_restore(flags) do { raw_local_irq_restore(flags); } while (0)
235 #define safe_halt()		do { raw_safe_halt(); } while (0)
236 
237 #endif /* CONFIG_TRACE_IRQFLAGS */
238 
239 #define local_save_flags(flags)	raw_local_save_flags(flags)
240 
241 /*
242  * Some architectures don't define arch_irqs_disabled(), so even if either
243  * definition would be fine we need to use different ones for the time being
244  * to avoid build issues.
245  */
246 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
247 #define irqs_disabled()					\
248 	({						\
249 		unsigned long _flags;			\
250 		raw_local_save_flags(_flags);		\
251 		raw_irqs_disabled_flags(_flags);	\
252 	})
253 #else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
254 #define irqs_disabled()	raw_irqs_disabled()
255 #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
256 
257 #define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags)
258 
259 DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
260 DEFINE_LOCK_GUARD_0(irqsave,
261 		    local_irq_save(_T->flags),
262 		    local_irq_restore(_T->flags),
263 		    unsigned long flags)
264 
265 #endif
266