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
29  static inline void lockdep_softirqs_on(unsigned long ip) { }
30  static inline void lockdep_softirqs_off(unsigned long ip) { }
31  static inline void lockdep_hardirqs_on_prepare(void) { }
32  static inline void lockdep_hardirqs_on(unsigned long ip) { }
33  static inline void lockdep_hardirqs_off(unsigned long ip) { }
34#endif
35
36#ifdef CONFIG_TRACE_IRQFLAGS
37
38DECLARE_PER_CPU(int, hardirqs_enabled);
39DECLARE_PER_CPU(int, hardirq_context);
40
41extern void trace_hardirqs_on_prepare(void);
42extern void trace_hardirqs_off_finish(void);
43extern void trace_hardirqs_on(void);
44extern 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()			\
51do {							\
52	if (__this_cpu_inc_return(hardirq_context) == 1)\
53		current->hardirq_threaded = 0;		\
54} while (0)
55# define lockdep_hardirq_threaded()		\
56do {						\
57	current->hardirq_threaded = 1;		\
58} while (0)
59# define lockdep_hardirq_exit()			\
60do {						\
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()		\
126do {						\
127	current->softirq_context++;		\
128} while (0)
129# define lockdep_softirq_exit()			\
130do {						\
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
149extern 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
259DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
260DEFINE_LOCK_GUARD_0(irqsave,
261		    local_irq_save(_T->flags),
262		    local_irq_restore(_T->flags),
263		    unsigned long flags)
264
265#endif
266