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