1/* 2 * arch/s390/kernel/s390_ext.c 3 * 4 * S390 version 5 * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation 6 * Author(s): Holger Smolinski (Holger.Smolinski@de.ibm.com), 7 * Martin Schwidefsky (schwidefsky@de.ibm.com) 8 */ 9 10#include <linux/module.h> 11#include <linux/kernel.h> 12#include <linux/slab.h> 13#include <linux/ftrace.h> 14#include <linux/errno.h> 15#include <linux/kernel_stat.h> 16#include <linux/interrupt.h> 17#include <asm/cputime.h> 18#include <asm/lowcore.h> 19#include <asm/s390_ext.h> 20#include <asm/irq_regs.h> 21#include <asm/irq.h> 22#include "entry.h" 23 24/* 25 * ext_int_hash[index] is the start of the list for all external interrupts 26 * that hash to this index. With the current set of external interrupts 27 * (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000 28 * iucv and 0x2603 pfault) this is always the first element. 29 */ 30ext_int_info_t *ext_int_hash[256] = { NULL, }; 31 32static inline int ext_hash(__u16 code) 33{ 34 return (code + (code >> 9)) & 0xff; 35} 36 37int register_external_interrupt(__u16 code, ext_int_handler_t handler) 38{ 39 ext_int_info_t *p; 40 int index; 41 42 p = kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC); 43 if (p == NULL) 44 return -ENOMEM; 45 p->code = code; 46 p->handler = handler; 47 index = ext_hash(code); 48 p->next = ext_int_hash[index]; 49 ext_int_hash[index] = p; 50 return 0; 51} 52 53int register_early_external_interrupt(__u16 code, ext_int_handler_t handler, 54 ext_int_info_t *p) 55{ 56 int index; 57 58 if (p == NULL) 59 return -EINVAL; 60 p->code = code; 61 p->handler = handler; 62 index = ext_hash(code); 63 p->next = ext_int_hash[index]; 64 ext_int_hash[index] = p; 65 return 0; 66} 67 68int unregister_external_interrupt(__u16 code, ext_int_handler_t handler) 69{ 70 ext_int_info_t *p, *q; 71 int index; 72 73 index = ext_hash(code); 74 q = NULL; 75 p = ext_int_hash[index]; 76 while (p != NULL) { 77 if (p->code == code && p->handler == handler) 78 break; 79 q = p; 80 p = p->next; 81 } 82 if (p == NULL) 83 return -ENOENT; 84 if (q != NULL) 85 q->next = p->next; 86 else 87 ext_int_hash[index] = p->next; 88 kfree(p); 89 return 0; 90} 91 92int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler, 93 ext_int_info_t *p) 94{ 95 ext_int_info_t *q; 96 int index; 97 98 if (p == NULL || p->code != code || p->handler != handler) 99 return -EINVAL; 100 index = ext_hash(code); 101 q = ext_int_hash[index]; 102 if (p != q) { 103 while (q != NULL) { 104 if (q->next == p) 105 break; 106 q = q->next; 107 } 108 if (q == NULL) 109 return -ENOENT; 110 q->next = p->next; 111 } else 112 ext_int_hash[index] = p->next; 113 return 0; 114} 115 116void __irq_entry do_extint(struct pt_regs *regs, unsigned short code) 117{ 118 ext_int_info_t *p; 119 int index; 120 struct pt_regs *old_regs; 121 122 old_regs = set_irq_regs(regs); 123 s390_idle_check(regs, S390_lowcore.int_clock, 124 S390_lowcore.async_enter_timer); 125 irq_enter(); 126 if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) 127 /* Serve timer interrupts first. */ 128 clock_comparator_work(); 129 kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++; 130 if (code != 0x1004) 131 __get_cpu_var(s390_idle).nohz_delay = 1; 132 index = ext_hash(code); 133 for (p = ext_int_hash[index]; p; p = p->next) { 134 if (likely(p->code == code)) 135 p->handler(code); 136 } 137 irq_exit(); 138 set_irq_regs(old_regs); 139} 140 141EXPORT_SYMBOL(register_external_interrupt); 142EXPORT_SYMBOL(unregister_external_interrupt); 143