include/asm-s390/hardirq.h

   1 /*
   2  *  include/asm-s390/hardirq.h
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   7  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
   8  *
   9  *  Derived from "include/asm-i386/hardirq.h"
  10  */
  11
  12 #ifndef __ASM_HARDIRQ_H
  13 #define __ASM_HARDIRQ_H
  14
  15 #include <linux/config.h>
  16 #include <linux/threads.h>
  17 #include <linux/sched.h>
  18 #include <linux/cache.h>
  19 #include <asm/lowcore.h>
  20
  21 /* irq_cpustat_t is unused currently, but could be converted
  22  * into a percpu variable instead of storing softirq_pending
  23  * on the lowcore */
  24 typedef struct {
  25         unsigned int __softirq_pending;
  26 } irq_cpustat_t;
  27
  28 #define local_softirq_pending() (S390_lowcore.softirq_pending)
  29
  30 /* this is always called with cpu == smp_processor_id() at the moment */
  31 static inline __u32
  32 softirq_pending(unsigned int cpu)
  33 {
  34         if (cpu == smp_processor_id())
  35                 return local_softirq_pending();
  36         return lowcore_ptr[cpu]->softirq_pending;
  37 }
  38
  39 #define __ARCH_IRQ_STAT
  40
  41 /*
  42  * We put the hardirq and softirq counter into the preemption
  43  * counter. The bitmask has the following meaning:
  44  *
  45  * - bits 0-7 are the preemption count (max preemption depth: 256)
  46  * - bits 8-15 are the softirq count (max # of softirqs: 256)
  47  * - bits 16-23 are the hardirq count (max # of hardirqs: 256)
  48  *
  49  * - ( bit 26 is the PREEMPT_ACTIVE flag. )
  50  *
  51  * PREEMPT_MASK: 0x000000ff
  52  * SOFTIRQ_MASK: 0x0000ff00
  53  * HARDIRQ_MASK: 0x00ff0000
  54  */
  55
  56 #define PREEMPT_BITS    8
  57 #define SOFTIRQ_BITS    8
  58 #define HARDIRQ_BITS    8
  59
  60 #define PREEMPT_SHIFT   0
  61 #define SOFTIRQ_SHIFT   (PREEMPT_SHIFT + PREEMPT_BITS)
  62 #define HARDIRQ_SHIFT   (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
  63
  64 extern void account_ticks(struct pt_regs *);
  65
  66 #define __ARCH_HAS_DO_SOFTIRQ
  67
  68 #define irq_enter()                                                     \
  69 do {                                                                    \
  70         (preempt_count() += HARDIRQ_OFFSET);                            \
  71 } while(0)
  72 #define irq_exit()                                                      \
  73 do {                                                                    \
  74         preempt_count() -= IRQ_EXIT_OFFSET;                             \
  75         if (!in_interrupt() && local_softirq_pending())                 \
  76                 /* Use the async. stack for softirq */                  \
  77                 do_softirq();                                           \
  78         preempt_enable_no_resched();                                    \
  79 } while (0)
  80
  81 #endif /* __ASM_HARDIRQ_H */