99b2d8df1d
The kernel uses the SIGP external call order code to signal other CPUs. When running with dedicated CPUs external calls don't get delivered immediately but within a fixed polling invervall. This can lead to delays where the system appears to do nothing. Replace the SIGP external call order with the SIGP emergency call order since this one gets delivered immediately. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
139 lines
3.3 KiB
C
139 lines
3.3 KiB
C
/*
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* arch/s390/kernel/s390_ext.c
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*
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* S390 version
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* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
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* Author(s): Holger Smolinski (Holger.Smolinski@de.ibm.com),
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* Martin Schwidefsky (schwidefsky@de.ibm.com)
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/errno.h>
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#include <linux/kernel_stat.h>
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#include <linux/interrupt.h>
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#include <asm/lowcore.h>
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#include <asm/s390_ext.h>
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#include <asm/irq.h>
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/*
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* ext_int_hash[index] is the start of the list for all external interrupts
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* that hash to this index. With the current set of external interrupts
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* (0x1202 external call, 0x1004 cpu timer, 0x2401 hwc console, 0x4000
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* iucv and 0x2603 pfault) this is always the first element.
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*/
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ext_int_info_t *ext_int_hash[256] = { 0, };
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static inline int ext_hash(__u16 code)
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{
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return (code + (code >> 9)) & 0xff;
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}
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int register_external_interrupt(__u16 code, ext_int_handler_t handler)
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{
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ext_int_info_t *p;
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int index;
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p = (ext_int_info_t *) kmalloc(sizeof(ext_int_info_t), GFP_ATOMIC);
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if (p == NULL)
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return -ENOMEM;
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p->code = code;
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p->handler = handler;
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index = ext_hash(code);
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p->next = ext_int_hash[index];
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ext_int_hash[index] = p;
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return 0;
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}
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int register_early_external_interrupt(__u16 code, ext_int_handler_t handler,
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ext_int_info_t *p)
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{
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int index;
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if (p == NULL)
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return -EINVAL;
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p->code = code;
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p->handler = handler;
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index = ext_hash(code);
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p->next = ext_int_hash[index];
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ext_int_hash[index] = p;
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return 0;
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}
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int unregister_external_interrupt(__u16 code, ext_int_handler_t handler)
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{
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ext_int_info_t *p, *q;
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int index;
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index = ext_hash(code);
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q = NULL;
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p = ext_int_hash[index];
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while (p != NULL) {
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if (p->code == code && p->handler == handler)
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break;
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q = p;
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p = p->next;
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}
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if (p == NULL)
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return -ENOENT;
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if (q != NULL)
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q->next = p->next;
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else
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ext_int_hash[index] = p->next;
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kfree(p);
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return 0;
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}
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int unregister_early_external_interrupt(__u16 code, ext_int_handler_t handler,
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ext_int_info_t *p)
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{
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ext_int_info_t *q;
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int index;
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if (p == NULL || p->code != code || p->handler != handler)
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return -EINVAL;
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index = ext_hash(code);
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q = ext_int_hash[index];
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if (p != q) {
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while (q != NULL) {
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if (q->next == p)
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break;
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q = q->next;
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}
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if (q == NULL)
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return -ENOENT;
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q->next = p->next;
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} else
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ext_int_hash[index] = p->next;
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return 0;
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}
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void do_extint(struct pt_regs *regs, unsigned short code)
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{
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ext_int_info_t *p;
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int index;
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irq_enter();
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asm volatile ("mc 0,0");
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if (S390_lowcore.int_clock >= S390_lowcore.jiffy_timer)
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/**
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* Make sure that the i/o interrupt did not "overtake"
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* the last HZ timer interrupt.
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*/
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account_ticks(regs);
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kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
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index = ext_hash(code);
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for (p = ext_int_hash[index]; p; p = p->next) {
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if (likely(p->code == code)) {
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if (likely(p->handler))
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p->handler(regs, code);
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}
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}
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irq_exit();
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}
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EXPORT_SYMBOL(register_external_interrupt);
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EXPORT_SYMBOL(unregister_external_interrupt);
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