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 /* entry.S is sensitive to the offsets of these fields */
  22 typedef struct {
  23         unsigned int __softirq_pending;
  24         unsigned int __syscall_count;
  25         struct task_struct * __ksoftirqd_task; /* waitqueue is too large */
  26 } ____cacheline_aligned irq_cpustat_t;
  27
  28 #include <linux/irq_cpustat.h>  /* Standard mappings for irq_cpustat_t above */
  29
  30 /*
  31  * We put the hardirq and softirq counter into the preemption
  32  * counter. The bitmask has the following meaning:
  33  *
  34  * - bits 0-7 are the preemption count (max preemption depth: 256)
  35  * - bits 8-15 are the softirq count (max # of softirqs: 256)
  36  * - bits 16-23 are the hardirq count (max # of hardirqs: 256)
  37  *
  38  * - ( bit 26 is the PREEMPT_ACTIVE flag. )
  39  *
  40  * PREEMPT_MASK: 0x000000ff
  41  * SOFTIRQ_MASK: 0x0000ff00
  42  * HARDIRQ_MASK: 0x00010000
  43  */
  44
  45 #define PREEMPT_BITS    8
  46 #define SOFTIRQ_BITS    8
  47 #define HARDIRQ_BITS    1
  48
  49 #define PREEMPT_SHIFT   0
  50 #define SOFTIRQ_SHIFT   (PREEMPT_SHIFT + PREEMPT_BITS)
  51 #define HARDIRQ_SHIFT   (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
  52
  53 #define __MASK(x)       ((1UL << (x))-1)
  54
  55 #define PREEMPT_MASK    (__MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
  56 #define SOFTIRQ_MASK    (__MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
  57 #define HARDIRQ_MASK    (__MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
  58
  59 #define hardirq_count() (preempt_count() & HARDIRQ_MASK)
  60 #define softirq_count() (preempt_count() & SOFTIRQ_MASK)
  61 #define irq_count()     (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
  62
  63 #define PREEMPT_OFFSET  (1UL << PREEMPT_SHIFT)
  64 #define SOFTIRQ_OFFSET  (1UL << SOFTIRQ_SHIFT)
  65 #define HARDIRQ_OFFSET  (1UL << HARDIRQ_SHIFT)
  66
  67 /*
  68  * Are we doing bottom half or hardware interrupt processing?
  69  * Are we in a softirq context? Interrupt context?
  70  */
  71 #define in_irq()                (hardirq_count())
  72 #define in_softirq()            (softirq_count())
  73 #define in_interrupt()          (irq_count())
  74
  75
  76 #define hardirq_trylock()       (!in_interrupt())
  77 #define hardirq_endlock()       do { } while (0)
  78
  79 #define irq_enter()             (preempt_count() += HARDIRQ_OFFSET)
  80
  81 extern void do_call_softirq(void);
  82
  83 #define invoke_softirq() do_call_softirq()
  84
  85 #ifdef CONFIG_PREEMPT
  86 # define in_atomic()    ((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
  87 # define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
  88 #else
  89 # define in_atomic()    (preempt_count() != 0)
  90 # define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
  91 #endif
  92
  93 #define irq_exit()                                                      \
  94 do {                                                                    \
  95         preempt_count() -= IRQ_EXIT_OFFSET;                             \
  96         if (!in_interrupt() && softirq_pending(smp_processor_id()))     \
  97                 /* Use the async. stack for softirq */                  \
  98                 do_call_softirq();                                      \
  99         preempt_enable_no_resched();                                    \
 100 } while (0)
 101
 102 #ifndef CONFIG_SMP
 103 # define synchronize_irq(irq)   barrier()
 104 #else
 105   extern void synchronize_irq(unsigned int irq);
 106 #endif /* CONFIG_SMP */
 107
 108 #endif /* __ASM_HARDIRQ_H */