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-rw-r--r--arch/s390x/kernel/irq.c423
1 files changed, 423 insertions, 0 deletions
diff --git a/arch/s390x/kernel/irq.c b/arch/s390x/kernel/irq.c
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+++ b/arch/s390x/kernel/irq.c
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+/*
+ * arch/s390/kernel/irq.c
+ *
+ * S390 version
+ * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ * Author(s): Ingo Adlung (adlung@de.ibm.com)
+ *
+ * Derived from "arch/i386/kernel/irq.c"
+ * Copyright (C) 1992, 1999 Linus Torvalds, Ingo Molnar
+ *
+ * S/390 I/O interrupt processing and I/O request processing is
+ * implemented in arch/s390/kernel/s390io.c
+ */
+#include <linux/config.h>
+#include <linux/ptrace.h>
+#include <linux/errno.h>
+#include <linux/kernel_stat.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/ioport.h>
+#include <linux/interrupt.h>
+#include <linux/timex.h>
+#include <linux/malloc.h>
+#include <linux/string.h>
+#include <linux/random.h>
+#include <linux/smp.h>
+#include <linux/threads.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/bitops.h>
+#include <asm/smp.h>
+#include <asm/pgtable.h>
+#include <asm/delay.h>
+#include <asm/lowcore.h>
+
+void s390_init_IRQ ( void );
+void s390_free_irq ( unsigned int irq, void *dev_id);
+int s390_request_irq( unsigned int irq,
+ void (*handler)(int, void *, struct pt_regs *),
+ unsigned long irqflags,
+ const char *devname,
+ void *dev_id);
+
+#if 0
+/*
+ * The following vectors are part of the Linux architecture, there
+ * is no hardware IRQ pin equivalent for them, they are triggered
+ * through the ICC by us (IPIs), via smp_message_pass():
+ */
+BUILD_SMP_INTERRUPT(reschedule_interrupt)
+BUILD_SMP_INTERRUPT(invalidate_interrupt)
+BUILD_SMP_INTERRUPT(stop_cpu_interrupt)
+BUILD_SMP_INTERRUPT(mtrr_interrupt)
+BUILD_SMP_INTERRUPT(spurious_interrupt)
+#endif
+
+#if 0
+int get_irq_list(char *buf)
+{
+ int i, j;
+ struct irqaction * action;
+ char *p = buf;
+
+ p += sprintf(p, " ");
+
+ for (j=0; j<smp_num_cpus; j++)
+ p += sprintf(p, "CPU%d ",j);
+
+ *p++ = '\n';
+
+ for (i = 0 ; i < NR_IRQS ; i++)
+ {
+ if (ioinfo[i] == INVALID_STORAGE_AREA)
+ continue;
+
+ action = ioinfo[i]->irq_desc.action;
+
+ if (!action)
+ continue;
+
+ p += sprintf(p, "%3d: ",i);
+#ifndef CONFIG_SMP
+ p += sprintf(p, "%10u ", kstat_irqs(i));
+#else
+ for (j=0; j<smp_num_cpus; j++)
+ p += sprintf( p, "%10u ",
+ kstat.irqs[cpu_logical_map(j)][i]);
+#endif
+ p += sprintf(p, " %14s", ioinfo[i]->irq_desc.handler->typename);
+ p += sprintf(p, " %s", action->name);
+
+ for (action=action->next; action; action = action->next)
+ {
+ p += sprintf(p, ", %s", action->name);
+
+ } /* endfor */
+
+ *p++ = '\n';
+
+ } /* endfor */
+
+ p += sprintf(p, "NMI: %10u\n", nmi_counter);
+#ifdef CONFIG_SMP
+ p += sprintf(p, "IPI: %10u\n", atomic_read(&ipi_count));
+#endif
+
+ return p - buf;
+}
+#endif
+
+/*
+ * Global interrupt locks for SMP. Allow interrupts to come in on any
+ * CPU, yet make cli/sti act globally to protect critical regions..
+ */
+#ifdef CONFIG_SMP
+atomic_t global_irq_holder = ATOMIC_INIT(NO_PROC_ID);
+atomic_t global_irq_lock = ATOMIC_INIT(0);
+atomic_t global_irq_count = ATOMIC_INIT(0);
+atomic_t global_bh_count;
+
+/*
+ * "global_cli()" is a special case, in that it can hold the
+ * interrupts disabled for a longish time, and also because
+ * we may be doing TLB invalidates when holding the global
+ * IRQ lock for historical reasons. Thus we may need to check
+ * SMP invalidate events specially by hand here (but not in
+ * any normal spinlocks)
+ *
+ * Thankfully we don't need this as we can deliver flush tlbs with
+ * interrupts disabled DJB :-)
+ */
+#define check_smp_invalidate(cpu)
+
+static void show(char * str)
+{
+ int i;
+ unsigned long *stack;
+ int cpu = smp_processor_id();
+
+ printk("\n%s, CPU %d:\n", str, cpu);
+ printk("irq: %d [%d]\n",
+ atomic_read(&global_irq_count),local_irq_count(smp_processor_id()));
+ printk("bh: %d [%d]\n",
+ atomic_read(&global_bh_count),local_bh_count(smp_processor_id()));
+ stack = (unsigned long *) &str;
+ for (i = 40; i ; i--) {
+ unsigned long x = *++stack;
+ if (x > (unsigned long) &init_task_union && x < (unsigned long) &vsprintf) {
+ printk("<[%08lx]> ", x);
+ }
+ }
+}
+
+#define MAXCOUNT 100000000
+
+static inline void wait_on_bh(void)
+{
+ int count = MAXCOUNT;
+ do {
+ if (!--count) {
+ show("wait_on_bh");
+ count = ~0;
+ }
+ /* nothing .. wait for the other bh's to go away */
+ } while (atomic_read(&global_bh_count) != 0);
+}
+
+static inline void wait_on_irq(int cpu)
+{
+ int count = MAXCOUNT;
+
+ for (;;) {
+
+ /*
+ * Wait until all interrupts are gone. Wait
+ * for bottom half handlers unless we're
+ * already executing in one..
+ */
+ if (!atomic_read(&global_irq_count)) {
+ if (local_bh_count(cpu)||
+ !atomic_read(&global_bh_count))
+ break;
+ }
+
+ /* Duh, we have to loop. Release the lock to avoid deadlocks */
+ atomic_set(&global_irq_lock, 0);
+
+ for (;;) {
+ if (!--count) {
+ show("wait_on_irq");
+ count = ~0;
+ }
+ __sti();
+ SYNC_OTHER_CORES(cpu);
+ __cli();
+ check_smp_invalidate(cpu);
+ if (atomic_read(&global_irq_count))
+ continue;
+ if (atomic_read(&global_irq_lock))
+ continue;
+ if (!local_bh_count(cpu)
+ && atomic_read(&global_bh_count))
+ continue;
+ if (!atomic_compare_and_swap(0, 1, &global_irq_lock))
+ break;
+ }
+ }
+}
+
+/*
+ * This is called when we want to synchronize with
+ * bottom half handlers. We need to wait until
+ * no other CPU is executing any bottom half handler.
+ *
+ * Don't wait if we're already running in an interrupt
+ * context or are inside a bh handler.
+ */
+void synchronize_bh(void)
+{
+ if (atomic_read(&global_bh_count) && !in_interrupt())
+ wait_on_bh();
+}
+
+/*
+ * This is called when we want to synchronize with
+ * interrupts. We may for example tell a device to
+ * stop sending interrupts: but to make sure there
+ * are no interrupts that are executing on another
+ * CPU we need to call this function.
+ */
+void synchronize_irq(void)
+{
+ if (atomic_read(&global_irq_count)) {
+ /* Stupid approach */
+ cli();
+ sti();
+ }
+}
+
+static inline void get_irqlock(int cpu)
+{
+ if (atomic_compare_and_swap(0,1,&global_irq_lock) != 0) {
+ /* do we already hold the lock? */
+ if ( cpu == atomic_read(&global_irq_holder))
+ return;
+ /* Uhhuh.. Somebody else got it. Wait.. */
+ do {
+ check_smp_invalidate(cpu);
+ } while (atomic_compare_and_swap(0,1,&global_irq_lock) != 0);
+ }
+ /*
+ * We also to make sure that nobody else is running
+ * in an interrupt context.
+ */
+ wait_on_irq(cpu);
+
+ /*
+ * Ok, finally..
+ */
+ atomic_set(&global_irq_holder,cpu);
+}
+
+#define EFLAGS_I_SHIFT 57
+
+/*
+ * A global "cli()" while in an interrupt context
+ * turns into just a local cli(). Interrupts
+ * should use spinlocks for the (very unlikely)
+ * case that they ever want to protect against
+ * each other.
+ *
+ * If we already have local interrupts disabled,
+ * this will not turn a local disable into a
+ * global one (problems with spinlocks: this makes
+ * save_flags+cli+sti usable inside a spinlock).
+ */
+void __global_cli(void)
+{
+ unsigned long flags;
+
+ __save_flags(flags);
+ if (flags & (1UL << EFLAGS_I_SHIFT)) {
+ int cpu = smp_processor_id();
+ __cli();
+ if (!in_irq())
+ get_irqlock(cpu);
+ }
+}
+
+void __global_sti(void)
+{
+
+ if (!in_irq())
+ release_irqlock(smp_processor_id());
+ __sti();
+}
+
+/*
+ * SMP flags value to restore to:
+ * 0 - global cli
+ * 1 - global sti
+ * 2 - local cli
+ * 3 - local sti
+ */
+unsigned long __global_save_flags(void)
+{
+ int retval;
+ int local_enabled;
+ unsigned long flags;
+
+ __save_flags(flags);
+ local_enabled = (flags >> EFLAGS_I_SHIFT) & 1;
+ /* default to local */
+ retval = 2 + local_enabled;
+
+ /* check for global flags if we're not in an interrupt */
+ if (!in_irq())
+ {
+ if (local_enabled)
+ retval = 1;
+ if (atomic_read(&global_irq_holder)== smp_processor_id())
+ retval = 0;
+ }
+ return retval;
+}
+
+void __global_restore_flags(unsigned long flags)
+{
+ switch (flags) {
+ case 0:
+ __global_cli();
+ break;
+ case 1:
+ __global_sti();
+ break;
+ case 2:
+ __cli();
+ break;
+ case 3:
+ __sti();
+ break;
+ default:
+ printk("global_restore_flags: %08lx (%08lx)\n",
+ flags, (&flags)[-1]);
+ }
+}
+
+#endif
+
+/*
+ * Note : This fuction should be eliminated as it doesn't comply with the
+ * S/390 irq scheme we have implemented ...
+ */
+int handle_IRQ_event(unsigned int irq, int cpu, struct pt_regs * regs)
+{
+ struct irqaction * action;
+ int status;
+
+ status = 0;
+
+ if ( ioinfo[irq] == INVALID_STORAGE_AREA )
+ return( -ENODEV);
+
+ action = ioinfo[irq]->irq_desc.action;
+
+ if (action)
+ {
+ status |= 1;
+
+ if (!(action->flags & SA_INTERRUPT))
+ __sti();
+
+ do
+ {
+ status |= action->flags;
+ action->handler(irq, action->dev_id, regs);
+ action = action->next;
+ } while (action);
+
+ if (status & SA_SAMPLE_RANDOM)
+ add_interrupt_randomness(irq);
+ __cli();
+
+ } /* endif */
+
+ return status;
+}
+
+void enable_nop(int irq)
+{
+}
+
+void __init init_IRQ(void)
+{
+ s390_init_IRQ();
+}
+
+
+void free_irq(unsigned int irq, void *dev_id)
+{
+ s390_free_irq( irq, dev_id);
+}
+
+
+int request_irq( unsigned int irq,
+ void (*handler)(int, void *, struct pt_regs *),
+ unsigned long irqflags,
+ const char *devname,
+ void *dev_id)
+{
+ return( s390_request_irq( irq, handler, irqflags, devname, dev_id ) );
+
+}
+
+void init_irq_proc(void)
+{
+ /* For now, nothing... */
+}
+
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