1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef LINUX_HARDIRQ_H 3#define LINUX_HARDIRQ_H 4 5#include <linux/context_tracking_state.h> 6#include <linux/preempt.h> 7#include <linux/lockdep.h> 8#include <linux/ftrace_irq.h> 9#include <linux/sched.h> 10#include <linux/vtime.h> 11#include <asm/hardirq.h> 12 13extern void synchronize_irq(unsigned int irq); 14extern bool synchronize_hardirq(unsigned int irq); 15 16#ifdef CONFIG_NO_HZ_FULL 17void __rcu_irq_enter_check_tick(void); 18#else 19static inline void __rcu_irq_enter_check_tick(void) { } 20#endif 21 22static __always_inline void rcu_irq_enter_check_tick(void) 23{ 24 if (context_tracking_enabled()) 25 __rcu_irq_enter_check_tick(); 26} 27 28/* 29 * It is safe to do non-atomic ops on ->hardirq_context, 30 * because NMI handlers may not preempt and the ops are 31 * always balanced, so the interrupted value of ->hardirq_context 32 * will always be restored. 33 */ 34#define __irq_enter() \ 35 do { \ 36 preempt_count_add(HARDIRQ_OFFSET); \ 37 lockdep_hardirq_enter(); \ 38 account_hardirq_enter(current); \ 39 } while (0) 40 41/* 42 * Like __irq_enter() without time accounting for fast 43 * interrupts, e.g. reschedule IPI where time accounting 44 * is more expensive than the actual interrupt. 45 */ 46#define __irq_enter_raw() \ 47 do { \ 48 preempt_count_add(HARDIRQ_OFFSET); \ 49 lockdep_hardirq_enter(); \ 50 } while (0) 51 52/* 53 * Enter irq context (on NO_HZ, update jiffies): 54 */ 55void irq_enter(void); 56/* 57 * Like irq_enter(), but RCU is already watching. 58 */ 59void irq_enter_rcu(void); 60 61/* 62 * Exit irq context without processing softirqs: 63 */ 64#define __irq_exit() \ 65 do { \ 66 account_hardirq_exit(current); \ 67 lockdep_hardirq_exit(); \ 68 preempt_count_sub(HARDIRQ_OFFSET); \ 69 } while (0) 70 71/* 72 * Like __irq_exit() without time accounting 73 */ 74#define __irq_exit_raw() \ 75 do { \ 76 lockdep_hardirq_exit(); \ 77 preempt_count_sub(HARDIRQ_OFFSET); \ 78 } while (0) 79 80/* 81 * Exit irq context and process softirqs if needed: 82 */ 83void irq_exit(void); 84 85/* 86 * Like irq_exit(), but return with RCU watching. 87 */ 88void irq_exit_rcu(void); 89 90#ifndef arch_nmi_enter 91#define arch_nmi_enter() do { } while (0) 92#define arch_nmi_exit() do { } while (0) 93#endif 94 95#ifdef CONFIG_TINY_RCU 96static inline void rcu_nmi_enter(void) { } 97static inline void rcu_nmi_exit(void) { } 98#else 99extern void rcu_nmi_enter(void); 100extern void rcu_nmi_exit(void); 101#endif 102 103/* 104 * NMI vs Tracing 105 * -------------- 106 * 107 * We must not land in a tracer until (or after) we've changed preempt_count 108 * such that in_nmi() becomes true. To that effect all NMI C entry points must 109 * be marked 'notrace' and call nmi_enter() as soon as possible. 110 */ 111 112/* 113 * nmi_enter() can nest up to 15 times; see NMI_BITS. 114 */ 115#define __nmi_enter() \ 116 do { \ 117 lockdep_off(); \ 118 arch_nmi_enter(); \ 119 printk_nmi_enter(); \ 120 BUG_ON(in_nmi() == NMI_MASK); \ 121 __preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ 122 } while (0) 123 124#define nmi_enter() \ 125 do { \ 126 __nmi_enter(); \ 127 lockdep_hardirq_enter(); \ 128 rcu_nmi_enter(); \ 129 instrumentation_begin(); \ 130 ftrace_nmi_enter(); \ 131 instrumentation_end(); \ 132 } while (0) 133 134#define __nmi_exit() \ 135 do { \ 136 BUG_ON(!in_nmi()); \ 137 __preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ 138 printk_nmi_exit(); \ 139 arch_nmi_exit(); \ 140 lockdep_on(); \ 141 } while (0) 142 143#define nmi_exit() \ 144 do { \ 145 instrumentation_begin(); \ 146 ftrace_nmi_exit(); \ 147 instrumentation_end(); \ 148 rcu_nmi_exit(); \ 149 lockdep_hardirq_exit(); \ 150 __nmi_exit(); \ 151 } while (0) 152 153#endif /* LINUX_HARDIRQ_H */ 154