/* * arch/s390/kernel/s390_ext.c * * S390 version * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation * Author(s): Holger Smolinski (Holger.Smolinski@de.ibm.com), * Martin Schwidefsky (schwidefsky@de.ibm.com) */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/errno.h> #include <linux/kernel_stat.h> #include <linux/interrupt.h> #include <asm/lowcore.h> #include <asm/s390_ext.h> #include <asm/irq_regs.h> #include <asm/irq.h> /* * ext_int_hash[index] is the start of the list for all external interrupts * that hash to this index. With the current set of external interrupts * (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000 * iucv and 0x2603 pfault) this is always the first element. */ ext_int_info_t *ext_int_hash[256] = { NULL, }; static inline int ext_hash(__u16 code) { return (code + (code >> 9)) & 0xff; } int register_external_interrupt(__u16 code, ext_int_handler_t handler) { ext_int_info_t *p; int index; p = (ext_int_info_t *) kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC); if (p == NULL) return -ENOMEM; p->code = code; p->handler = handler; index = ext_hash(code); p->next = ext_int_hash[index]; ext_int_hash[index] = p; return 0; } int register_early_external_interrupt(__u16 code, ext_int_handler_t handler, ext_int_info_t *p) { int index; if (p == NULL) return -EINVAL; p->code = code; p->handler = handler; index = ext_hash(code); p->next = ext_int_hash[index]; ext_int_hash[index] = p; return 0; } int unregister_external_interrupt(__u16 code, ext_int_handler_t handler) { ext_int_info_t *p, *q; int index; index = ext_hash(code); q = NULL; p = ext_int_hash[index]; while (p != NULL) { if (p->code == code && p->handler == handler) break; q = p; p = p->next; } if (p == NULL) return -ENOENT; if (q != NULL) q->next = p->next; else ext_int_hash[index] = p->next; kfree(p); return 0; } int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler, ext_int_info_t *p) { ext_int_info_t *q; int index; if (p == NULL || p->code != code || p->handler != handler) return -EINVAL; index = ext_hash(code); q = ext_int_hash[index]; if (p != q) { while (q != NULL) { if (q->next == p) break; q = q->next; } if (q == NULL) return -ENOENT; q->next = p->next; } else ext_int_hash[index] = p->next; return 0; } void do_extint(struct pt_regs *regs, unsigned short code) { ext_int_info_t *p; int index; struct pt_regs *old_regs; old_regs = set_irq_regs(regs); irq_enter(); asm volatile ("mc 0,0"); if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer) /** * Make sure that the i/o interrupt did not "overtake" * the last HZ timer interrupt. */ account_ticks(); kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++; index = ext_hash(code); for (p = ext_int_hash[index]; p; p = p->next) { if (likely(p->code == code)) { if (likely(p->handler)) p->handler(code); } } irq_exit(); set_irq_regs(old_regs); } EXPORT_SYMBOL(register_external_interrupt); EXPORT_SYMBOL(unregister_external_interrupt);