root/include/linux/interrupt.h

/* */

INCLUDED FROM

DEFINITIONS

1. mark_bh
2. disable_bh
3. enable_bh
4. start_bh_atomic
5. end_bh_atomic

   1 /* interrupt.h */
   2 #ifndef _LINUX_INTERRUPT_H
   3 #define _LINUX_INTERRUPT_H
   4 
   5 #include <linux/linkage.h>
   6 #include <asm/bitops.h>
   7 
   8 struct bh_struct {
   9         void (*routine)(void *);
  10         void *data;
  11 };
  12 
  13 extern unsigned long bh_active;
  14 extern unsigned long bh_mask;
  15 extern struct bh_struct bh_base[32];
  16 
  17 asmlinkage void do_bottom_half(void);
  18 
  19 /* Who gets which entry in bh_base.  Things which will occur most often
  20    should come first - in which case NET should be up the top with SERIAL/TQUEUE! */
  21    
  22 enum {
  23         TIMER_BH = 0,
  24         CONSOLE_BH,
  25         TQUEUE_BH,
  26         SERIAL_BH,
  27         NET_BH,
  28         IMMEDIATE_BH,
  29         KEYBOARD_BH,
  30         CYCLADES_BH
  31 };
  32 
  33 extern inline void mark_bh(int nr)
     /*  */
  34 {
  35         set_bit(nr, &bh_active);
  36 }
  37 
  38 extern inline void disable_bh(int nr)
     /*  */
  39 {
  40         clear_bit(nr, &bh_mask);
  41 }
  42 
  43 extern inline void enable_bh(int nr)
     /*  */
  44 {
  45         set_bit(nr, &bh_mask);
  46 }
  47 
  48 extern inline void start_bh_atomic(void)
     /*  */
  49 {
  50         intr_count++;
  51 }
  52 
  53 extern inline void end_bh_atomic(void)
     /*  */
  54 {
  55         if (intr_count == 1 && (bh_active & bh_mask))
  56                 do_bottom_half();
  57         intr_count--;
  58 }
  59 
  60 /*
  61  * Autoprobing for irqs:
  62  *
  63  * probe_irq_on() and probe_irq_off() provide robust primitives
  64  * for accurate IRQ probing during kernel initialization.  They are
  65  * reasonably simple to use, are not "fooled" by spurious interrupts,
  66  * and, unlike other attempts at IRQ probing, they do not get hung on
  67  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
  68  *
  69  * For reasonably foolproof probing, use them as follows:
  70  *
  71  * 1. clear and/or mask the device's internal interrupt.
  72  * 2. sti();
  73  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
  74  * 4. enable the device and cause it to trigger an interrupt.
  75  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
  76  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
  77  * 7. service the device to clear its pending interrupt.
  78  * 8. loop again if paranoia is required.
  79  *
  80  * probe_irq_on() returns a mask of snarfed irq's.
  81  *
  82  * probe_irq_off() takes the mask as a parameter,
  83  * and returns the irq number which occurred,
  84  * or zero if none occurred, or a negative irq number
  85  * if more than one irq occurred.
  86  */
  87 extern unsigned int probe_irq_on(void); /* returns 0 on failure */
  88 extern int probe_irq_off(unsigned int); /* returns 0 or negative on failure */
  89 
  90 #endif

/* */