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 13 extern void synchronize_irq(unsigned int irq); 14 extern bool synchronize_hardirq(unsigned int irq); 15 16 #ifdef CONFIG_NO_HZ_FULL 17 void __rcu_irq_enter_check_tick(void); 18 #else __rcu_irq_enter_check_tick(void)19static inline void __rcu_irq_enter_check_tick(void) { } 20 #endif 21 rcu_irq_enter_check_tick(void)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 */ 55 void irq_enter(void); 56 /* 57 * Like irq_enter(), but RCU is already watching. 58 */ 59 void 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 */ 83 void irq_exit(void); 84 85 /* 86 * Like irq_exit(), but return with RCU watching. 87 */ 88 void 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 rcu_nmi_enter(void)96static inline void rcu_nmi_enter(void) { } rcu_nmi_exit(void)97static inline void rcu_nmi_exit(void) { } 98 #else 99 extern void rcu_nmi_enter(void); 100 extern 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 BUG_ON(in_nmi() == NMI_MASK); \ 120 __preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ 121 } while (0) 122 123 #define nmi_enter() \ 124 do { \ 125 __nmi_enter(); \ 126 lockdep_hardirq_enter(); \ 127 rcu_nmi_enter(); \ 128 instrumentation_begin(); \ 129 ftrace_nmi_enter(); \ 130 instrumentation_end(); \ 131 } while (0) 132 133 #define __nmi_exit() \ 134 do { \ 135 BUG_ON(!in_nmi()); \ 136 __preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ 137 arch_nmi_exit(); \ 138 lockdep_on(); \ 139 } while (0) 140 141 #define nmi_exit() \ 142 do { \ 143 instrumentation_begin(); \ 144 ftrace_nmi_exit(); \ 145 instrumentation_end(); \ 146 rcu_nmi_exit(); \ 147 lockdep_hardirq_exit(); \ 148 __nmi_exit(); \ 149 } while (0) 150 151 #endif /* LINUX_HARDIRQ_H */ 152