irqflags.h

  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
 21struct task_struct;
 22
 23/* Currently lockdep_softirqs_on/off is used only by lockdep */
 24#ifdef CONFIG_PROVE_LOCKING
 25  extern void lockdep_softirqs_on(unsigned long ip);
 26  extern void lockdep_softirqs_off(unsigned long ip);
 27  extern void lockdep_hardirqs_on_prepare(void);
 28  extern void lockdep_hardirqs_on(unsigned long ip);
 29  extern void lockdep_hardirqs_off(unsigned long ip);
 30  extern void lockdep_cleanup_dead_cpu(unsigned int cpu,
 31				       struct task_struct *idle);
 32#else
 33  static inline void lockdep_softirqs_on(unsigned long ip) { }
 34  static inline void lockdep_softirqs_off(unsigned long ip) { }
 35  static inline void lockdep_hardirqs_on_prepare(void) { }
 36  static inline void lockdep_hardirqs_on(unsigned long ip) { }
 37  static inline void lockdep_hardirqs_off(unsigned long ip) { }
 38  static inline void lockdep_cleanup_dead_cpu(unsigned int cpu,
 39					      struct task_struct *idle) {}
 40#endif
 41
 42#ifdef CONFIG_TRACE_IRQFLAGS
 43
 44DECLARE_PER_CPU(int, hardirqs_enabled);
 45DECLARE_PER_CPU(int, hardirq_context);
 46
 47extern void trace_hardirqs_on_prepare(void);
 48extern void trace_hardirqs_off_finish(void);
 49extern void trace_hardirqs_on(void);
 50extern void trace_hardirqs_off(void);
 51
 52# define lockdep_hardirq_context()	(raw_cpu_read(hardirq_context))
 53# define lockdep_softirq_context(p)	((p)->softirq_context)
 54# define lockdep_hardirqs_enabled()	(this_cpu_read(hardirqs_enabled))
 55# define lockdep_softirqs_enabled(p)	((p)->softirqs_enabled)
 56# define lockdep_hardirq_enter()			\
 57do {							\
 58	if (__this_cpu_inc_return(hardirq_context) == 1)\
 59		current->hardirq_threaded = 0;		\
 60} while (0)
 61# define lockdep_hardirq_threaded()		\
 62do {						\
 63	current->hardirq_threaded = 1;		\
 64} while (0)
 65# define lockdep_hardirq_exit()			\
 66do {						\
 67	__this_cpu_dec(hardirq_context);	\
 68} while (0)
 69
 70# define lockdep_hrtimer_enter(__hrtimer)		\
 71({							\
 72	bool __expires_hardirq = true;			\
 73							\
 74	if (!__hrtimer->is_hard) {			\
 75		current->irq_config = 1;		\
 76		__expires_hardirq = false;		\
 77	}						\
 78	__expires_hardirq;				\
 79})
 80
 81# define lockdep_hrtimer_exit(__expires_hardirq)	\
 82	do {						\
 83		if (!__expires_hardirq)			\
 84			current->irq_config = 0;	\
 85	} while (0)
 86
 87# define lockdep_posixtimer_enter()				\
 88	  do {							\
 89		  current->irq_config = 1;			\
 90	  } while (0)
 91
 92# define lockdep_posixtimer_exit()				\
 93	  do {							\
 94		  current->irq_config = 0;			\
 95	  } while (0)
 96
 97# define lockdep_irq_work_enter(_flags)					\
 98	  do {								\
 99		  if (!((_flags) & IRQ_WORK_HARD_IRQ))			\
100			current->irq_config = 1;			\
101	  } while (0)
102# define lockdep_irq_work_exit(_flags)					\
103	  do {								\
104		  if (!((_flags) & IRQ_WORK_HARD_IRQ))			\
105			current->irq_config = 0;			\
106	  } while (0)
107
108#else
109# define trace_hardirqs_on_prepare()		do { } while (0)
110# define trace_hardirqs_off_finish()		do { } while (0)
111# define trace_hardirqs_on()			do { } while (0)
112# define trace_hardirqs_off()			do { } while (0)
113# define lockdep_hardirq_context()		0
114# define lockdep_softirq_context(p)		0
115# define lockdep_hardirqs_enabled()		0
116# define lockdep_softirqs_enabled(p)		0
117# define lockdep_hardirq_enter()		do { } while (0)
118# define lockdep_hardirq_threaded()		do { } while (0)
119# define lockdep_hardirq_exit()			do { } while (0)
120# define lockdep_softirq_enter()		do { } while (0)
121# define lockdep_softirq_exit()			do { } while (0)
122# define lockdep_hrtimer_enter(__hrtimer)	false
123# define lockdep_hrtimer_exit(__context)	do { (void)(__context); } while (0)
124# define lockdep_posixtimer_enter()		do { } while (0)
125# define lockdep_posixtimer_exit()		do { } while (0)
126# define lockdep_irq_work_enter(__work)		do { } while (0)
127# define lockdep_irq_work_exit(__work)		do { } while (0)
128#endif
129
130#if defined(CONFIG_TRACE_IRQFLAGS) && !defined(CONFIG_PREEMPT_RT)
131# define lockdep_softirq_enter()		\
132do {						\
133	current->softirq_context++;		\
134} while (0)
135# define lockdep_softirq_exit()			\
136do {						\
137	current->softirq_context--;		\
138} while (0)
139
140#else
141# define lockdep_softirq_enter()		do { } while (0)
142# define lockdep_softirq_exit()			do { } while (0)
143#endif
144
145#if defined(CONFIG_IRQSOFF_TRACER) || \
146	defined(CONFIG_PREEMPT_TRACER)
147 extern void stop_critical_timings(void);
148 extern void start_critical_timings(void);
149#else
150# define stop_critical_timings() do { } while (0)
151# define start_critical_timings() do { } while (0)
152#endif
153
154#ifdef CONFIG_DEBUG_IRQFLAGS
155extern void warn_bogus_irq_restore(void);
156#define raw_check_bogus_irq_restore()			\
157	do {						\
158		if (unlikely(!arch_irqs_disabled()))	\
159			warn_bogus_irq_restore();	\
160	} while (0)
161#else
162#define raw_check_bogus_irq_restore() do { } while (0)
163#endif
164
165/*
166 * Wrap the arch provided IRQ routines to provide appropriate checks.
167 */
168#define raw_local_irq_disable()		arch_local_irq_disable()
169#define raw_local_irq_enable()		arch_local_irq_enable()
170#define raw_local_irq_save(flags)			\
171	do {						\
172		typecheck(unsigned long, flags);	\
173		flags = arch_local_irq_save();		\
174	} while (0)
175#define raw_local_irq_restore(flags)			\
176	do {						\
177		typecheck(unsigned long, flags);	\
178		raw_check_bogus_irq_restore();		\
179		arch_local_irq_restore(flags);		\
180	} while (0)
181#define raw_local_save_flags(flags)			\
182	do {						\
183		typecheck(unsigned long, flags);	\
184		flags = arch_local_save_flags();	\
185	} while (0)
186#define raw_irqs_disabled_flags(flags)			\
187	({						\
188		typecheck(unsigned long, flags);	\
189		arch_irqs_disabled_flags(flags);	\
190	})
191#define raw_irqs_disabled()		(arch_irqs_disabled())
192#define raw_safe_halt()			arch_safe_halt()
193
194/*
195 * The local_irq_*() APIs are equal to the raw_local_irq*()
196 * if !TRACE_IRQFLAGS.
197 */
198#ifdef CONFIG_TRACE_IRQFLAGS
199
200#define local_irq_enable()				\
201	do {						\
202		trace_hardirqs_on();			\
203		raw_local_irq_enable();			\
204	} while (0)
205
206#define local_irq_disable()				\
207	do {						\
208		bool was_disabled = raw_irqs_disabled();\
209		raw_local_irq_disable();		\
210		if (!was_disabled)			\
211			trace_hardirqs_off();		\
212	} while (0)
213
214#define local_irq_save(flags)				\
215	do {						\
216		raw_local_irq_save(flags);		\
217		if (!raw_irqs_disabled_flags(flags))	\
218			trace_hardirqs_off();		\
219	} while (0)
220
221#define local_irq_restore(flags)			\
222	do {						\
223		if (!raw_irqs_disabled_flags(flags))	\
224			trace_hardirqs_on();		\
225		raw_local_irq_restore(flags);		\
226	} while (0)
227
228#define safe_halt()				\
229	do {					\
230		trace_hardirqs_on();		\
231		raw_safe_halt();		\
232	} while (0)
233
234
235#else /* !CONFIG_TRACE_IRQFLAGS */
236
237#define local_irq_enable()	do { raw_local_irq_enable(); } while (0)
238#define local_irq_disable()	do { raw_local_irq_disable(); } while (0)
239#define local_irq_save(flags)	do { raw_local_irq_save(flags); } while (0)
240#define local_irq_restore(flags) do { raw_local_irq_restore(flags); } while (0)
241#define safe_halt()		do { raw_safe_halt(); } while (0)
242
243#endif /* CONFIG_TRACE_IRQFLAGS */
244
245#define local_save_flags(flags)	raw_local_save_flags(flags)
246
247/*
248 * Some architectures don't define arch_irqs_disabled(), so even if either
249 * definition would be fine we need to use different ones for the time being
250 * to avoid build issues.
251 */
252#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
253#define irqs_disabled()					\
254	({						\
255		unsigned long _flags;			\
256		raw_local_save_flags(_flags);		\
257		raw_irqs_disabled_flags(_flags);	\
258	})
259#else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
260#define irqs_disabled()	raw_irqs_disabled()
261#endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
262
263#define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags)
264
265DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
266DEFINE_LOCK_GUARD_0(irqsave,
267		    local_irq_save(_T->flags),
268		    local_irq_restore(_T->flags),
269		    unsigned long flags)
270
271#endif