include/asm-ppc/hardirq.h

   1 #ifdef __KERNEL__
   2 #ifndef __ASM_HARDIRQ_H
   3 #define __ASM_HARDIRQ_H
   4
   5 #include <linux/config.h>
   6 #include <linux/cache.h>
   7 #include <linux/smp_lock.h>
   8 #include <asm/irq.h>
   9
  10 /* The __last_jiffy_stamp field is needed to ensure that no decrementer
  11  * interrupt is lost on SMP machines. Since on most CPUs it is in the same
  12  * cache line as local_irq_count, it is cheap to access and is also used on UP
  13  * for uniformity.
  14  */
  15 typedef struct {
  16         unsigned long __softirq_pending;        /* set_bit is used on this */
  17         unsigned int __syscall_count;
  18         struct task_struct * __ksoftirqd_task;
  19         unsigned int __last_jiffy_stamp;
  20 } ____cacheline_aligned irq_cpustat_t;
  21
  22 #include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */
  23
  24 #define last_jiffy_stamp(cpu) __IRQ_STAT((cpu), __last_jiffy_stamp)
  25
  26 /*
  27  * We put the hardirq and softirq counter into the preemption
  28  * counter. The bitmask has the following meaning:
  29  *
  30  * - bits 0-7 are the preemption count (max preemption depth: 256)
  31  * - bits 8-15 are the softirq count (max # of softirqs: 256)
  32  * - bits 16-23 are the hardirq count (max # of hardirqs: 256)
  33  *
  34  * - ( bit 26 is the PREEMPT_ACTIVE flag. )
  35  *
  36  * PREEMPT_MASK: 0x000000ff
  37  * SOFTIRQ_MASK: 0x0000ff00
  38  * HARDIRQ_MASK: 0x00ff0000
  39  */
  40
  41 #define PREEMPT_BITS    8
  42 #define SOFTIRQ_BITS    8
  43 #define HARDIRQ_BITS    8
  44
  45 #define PREEMPT_SHIFT   0
  46 #define SOFTIRQ_SHIFT   (PREEMPT_SHIFT + PREEMPT_BITS)
  47 #define HARDIRQ_SHIFT   (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
  48
  49 #define __MASK(x)       ((1UL << (x))-1)
  50
  51 #define PREEMPT_MASK    (__MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
  52 #define HARDIRQ_MASK    (__MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
  53 #define SOFTIRQ_MASK    (__MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
  54
  55 #define hardirq_count() (preempt_count() & HARDIRQ_MASK)
  56 #define softirq_count() (preempt_count() & SOFTIRQ_MASK)
  57 #define irq_count()     (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
  58
  59 #define PREEMPT_OFFSET  (1UL << PREEMPT_SHIFT)
  60 #define SOFTIRQ_OFFSET  (1UL << SOFTIRQ_SHIFT)
  61 #define HARDIRQ_OFFSET  (1UL << HARDIRQ_SHIFT)
  62
  63 /*
  64  * The hardirq mask has to be large enough to have
  65  * space for potentially all IRQ sources in the system
  66  * nesting on a single CPU:
  67  */
  68 #if (1 << HARDIRQ_BITS) < NR_IRQS
  69 # error HARDIRQ_BITS is too low!
  70 #endif
  71
  72 /*
  73  * Are we doing bottom half or hardware interrupt processing?
  74  * Are we in a softirq context? Interrupt context?
  75  */
  76 #define in_irq()                (hardirq_count())
  77 #define in_softirq()            (softirq_count())
  78 #define in_interrupt()          (irq_count())
  79
  80
  81 #define hardirq_trylock()       (!in_interrupt())
  82 #define hardirq_endlock()       do { } while (0)
  83
  84 #define irq_enter()             (preempt_count() += HARDIRQ_OFFSET)
  85
  86 #ifdef CONFIG_PREEMPT
  87 # define in_atomic()    ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
  88 # define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
  89 #else
  90 # define in_atomic()    (preempt_count() != 0)
  91 # define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
  92 #endif
  93 #define irq_exit()                                                      \
  94 do {                                                                    \
  95         preempt_count() -= IRQ_EXIT_OFFSET;                             \
  96         if (!in_interrupt() && softirq_pending(smp_processor_id()))     \
  97                 do_softirq();                                           \
  98         preempt_enable_no_resched();                                    \
  99 } while (0)
 100
 101 #ifndef CONFIG_SMP
 102 # define synchronize_irq(irq)   barrier()
 103 #else
 104   extern void synchronize_irq(unsigned int irq);
 105 #endif /* CONFIG_SMP */
 106
 107 extern void show_stack(unsigned long *sp);
 108
 109 #endif /* __ASM_HARDIRQ_H */
 110 #endif /* __KERNEL__ */