1 #ifndef LINUX_HARDIRQ_H 2 #define LINUX_HARDIRQ_H 3 4 #include <linux/preempt.h> 5 #include <linux/smp_lock.h> 6 #include <linux/lockdep.h> 7 #include <asm/hardirq.h> 8 #include <asm/system.h> 9 10 /* 11 * We put the hardirq and softirq counter into the preemption 12 * counter. The bitmask has the following meaning: 13 * 14 * - bits 0-7 are the preemption count (max preemption depth: 256) 15 * - bits 8-15 are the softirq count (max # of softirqs: 256) 16 * 17 * The hardirq count can be overridden per architecture, the default is: 18 * 19 * - bits 16-27 are the hardirq count (max # of hardirqs: 4096) 20 * - ( bit 28 is the PREEMPT_ACTIVE flag. ) 21 * 22 * PREEMPT_MASK: 0x000000ff 23 * SOFTIRQ_MASK: 0x0000ff00 24 * HARDIRQ_MASK: 0x0fff0000 25 */ 26 #define PREEMPT_BITS 8 27 #define SOFTIRQ_BITS 8 28 29 #ifndef HARDIRQ_BITS 30 #define HARDIRQ_BITS 12 31 /* 32 * The hardirq mask has to be large enough to have space for potentially 33 * all IRQ sources in the system nesting on a single CPU. 34 */ 35 #if (1 << HARDIRQ_BITS) < NR_IRQS 36 # error HARDIRQ_BITS is too low! 37 #endif 38 #endif 39 40 #define PREEMPT_SHIFT 0 41 #define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS) 42 #define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS) 43 44 #define __IRQ_MASK(x) ((1UL << (x))-1) 45 46 #define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT) 47 #define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT) 48 #define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT) 49 50 #define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT) 51 #define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT) 52 #define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT) 53 54 #if PREEMPT_ACTIVE < (1 << (HARDIRQ_SHIFT + HARDIRQ_BITS)) 55 #error PREEMPT_ACTIVE is too low! 56 #endif 57 58 #define hardirq_count() (preempt_count() & HARDIRQ_MASK) 59 #define softirq_count() (preempt_count() & SOFTIRQ_MASK) 60 #define irq_count() (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK)) 61 62 /* 63 * Are we doing bottom half or hardware interrupt processing? 64 * Are we in a softirq context? Interrupt context? 65 */ 66 #define in_irq() (hardirq_count()) 67 #define in_softirq() (softirq_count()) 68 #define in_interrupt() (irq_count()) 69 70 #if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL) 71 # define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked()) 72 #else 73 # define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0) 74 #endif 75 76 #ifdef CONFIG_PREEMPT 77 # define preemptible() (preempt_count() == 0 && !irqs_disabled()) 78 # define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1) 79 #else 80 # define preemptible() 0 81 # define IRQ_EXIT_OFFSET HARDIRQ_OFFSET 82 #endif 83 84 #ifdef CONFIG_SMP 85 extern void synchronize_irq(unsigned int irq); 86 #else 87 # define synchronize_irq(irq) barrier() 88 #endif 89 90 struct task_struct; 91 92 #ifndef CONFIG_VIRT_CPU_ACCOUNTING account_system_vtime(struct task_struct * tsk)93static inline void account_system_vtime(struct task_struct *tsk) 94 { 95 } 96 #endif 97 98 /* 99 * It is safe to do non-atomic ops on ->hardirq_context, 100 * because NMI handlers may not preempt and the ops are 101 * always balanced, so the interrupted value of ->hardirq_context 102 * will always be restored. 103 */ 104 #define irq_enter() \ 105 do { \ 106 account_system_vtime(current); \ 107 add_preempt_count(HARDIRQ_OFFSET); \ 108 trace_hardirq_enter(); \ 109 } while (0) 110 111 /* 112 * Exit irq context without processing softirqs: 113 */ 114 #define __irq_exit() \ 115 do { \ 116 trace_hardirq_exit(); \ 117 account_system_vtime(current); \ 118 sub_preempt_count(HARDIRQ_OFFSET); \ 119 } while (0) 120 121 /* 122 * Exit irq context and process softirqs if needed: 123 */ 124 extern void irq_exit(void); 125 126 #define nmi_enter() do { lockdep_off(); irq_enter(); } while (0) 127 #define nmi_exit() do { __irq_exit(); lockdep_on(); } while (0) 128 129 #endif /* LINUX_HARDIRQ_H */ 130