include/asm-alpha/hardirq.h

   1 #ifndef _ALPHA_HARDIRQ_H
   2 #define _ALPHA_HARDIRQ_H
   3
   4 #include <linux/config.h>
   5 #include <linux/threads.h>
   6 #include <linux/cache.h>
   7
   8
   9 /* entry.S is sensitive to the offsets of these fields */
  10 typedef struct {
  11         unsigned long __softirq_pending;
  12         unsigned int __syscall_count;
  13         unsigned long idle_timestamp;
  14         struct task_struct * __ksoftirqd_task;
  15 } ____cacheline_aligned irq_cpustat_t;
  16
  17 #include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */
  18
  19 /*
  20  * We put the hardirq and softirq counter into the preemption
  21  * counter. The bitmask has the following meaning:
  22  *
  23  * - bits 0-7 are the preemption count (max preemption depth: 256)
  24  * - bits 8-15 are the softirq count (max # of softirqs: 256)
  25  * - bits 16-27 are the hardirq count (max # of hardirqs: 4096)
  26  *
  27  * - ( bit 30 is the PREEMPT_ACTIVE flag. )
  28  *
  29  * PREEMPT_MASK: 0x000000ff
  30  * SOFTIRQ_MASK: 0x0000ff00
  31  * HARDIRQ_MASK: 0x0fff0000
  32  */
  33
  34 #define PREEMPT_BITS    8
  35 #define SOFTIRQ_BITS    8
  36 #define HARDIRQ_BITS    12
  37
  38 #define PREEMPT_SHIFT   0
  39 #define SOFTIRQ_SHIFT   (PREEMPT_SHIFT + PREEMPT_BITS)
  40 #define HARDIRQ_SHIFT   (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
  41
  42 /*
  43  * The hardirq mask has to be large enough to have
  44  * space for potentially nestable IRQ sources in the system
  45  * to nest on a single CPU. On Alpha, interrupts are masked at the CPU
  46  * by IPL as well as at the system level. We only have 8 IPLs (UNIX PALcode)
  47  * so we really only have 8 nestable IRQs, but allow some overhead
  48  */
  49 #if (1 << HARDIRQ_BITS) < 16
  50 #error HARDIRQ_BITS is too low!
  51 #endif
  52
  53 #define irq_enter()             (preempt_count() += HARDIRQ_OFFSET)
  54 #define irq_exit()                                              \
  55 do {                                                            \
  56                 preempt_count() -= IRQ_EXIT_OFFSET;             \
  57                 if (!in_interrupt() &&                          \
  58                     softirq_pending(smp_processor_id()))        \
  59                         do_softirq();                           \
  60                 preempt_enable_no_resched();                    \
  61 } while (0)
  62
  63 #endif /* _ALPHA_HARDIRQ_H */