hardirq.h revision c559cd81139f97cecad1ad91a0b2e25a5936d531
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 85extern void synchronize_irq(unsigned int irq); 86#else 87# define synchronize_irq(irq) barrier() 88#endif 89 90struct task_struct; 91 92#ifndef CONFIG_VIRT_CPU_ACCOUNTING 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 */ 124extern 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