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