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 __last_jiffy_stamp;
  18 } ____cacheline_aligned irq_cpustat_t;
  19
  20 #include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */
  21
  22 #define last_jiffy_stamp(cpu) __IRQ_STAT((cpu), __last_jiffy_stamp)
  23
  24 /*
  25  * We put the hardirq and softirq counter into the preemption
  26  * counter. The bitmask has the following meaning:
  27  *
  28  * - bits 0-7 are the preemption count (max preemption depth: 256)
  29  * - bits 8-15 are the softirq count (max # of softirqs: 256)
  30  * - bits 16-23 are the hardirq count (max # of hardirqs: 256)
  31  *
  32  * - ( bit 26 is the PREEMPT_ACTIVE flag. )
  33  *
  34  * PREEMPT_MASK: 0x000000ff
  35  * SOFTIRQ_MASK: 0x0000ff00
  36  * HARDIRQ_MASK: 0x00ff0000
  37  */
  38
  39 #define PREEMPT_BITS    8
  40 #define SOFTIRQ_BITS    8
  41 #define HARDIRQ_BITS    8
  42
  43 #define PREEMPT_SHIFT   0
  44 #define SOFTIRQ_SHIFT   (PREEMPT_SHIFT + PREEMPT_BITS)
  45 #define HARDIRQ_SHIFT   (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
  46
  47 /*
  48  * The hardirq mask has to be large enough to have
  49  * space for potentially all IRQ sources in the system
  50  * nesting on a single CPU:
  51  */
  52 #if (1 << HARDIRQ_BITS) < NR_IRQS
  53 # error HARDIRQ_BITS is too low!
  54 #endif
  55
  56 #define irq_enter()             (preempt_count() += HARDIRQ_OFFSET)
  57 #define irq_exit()                                                      \
  58 do {                                                                    \
  59         preempt_count() -= IRQ_EXIT_OFFSET;                             \
  60         if (!in_interrupt() && softirq_pending(smp_processor_id()))     \
  61                 do_softirq();                                           \
  62         preempt_enable_no_resched();                                    \
  63 } while (0)
  64
  65 #endif /* __ASM_HARDIRQ_H */
  66 #endif /* __KERNEL__ */