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-rw-r--r--arch/sh/kernel/irq.c485
1 files changed, 485 insertions, 0 deletions
diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
new file mode 100644
index 000000000..f75af5003
--- /dev/null
+++ b/arch/sh/kernel/irq.c
@@ -0,0 +1,485 @@
+/*
+ * linux/arch/sh/kernel/irq.c
+ *
+ * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
+ *
+ *
+ * SuperH version: Copyright (C) 1999 Niibe Yutaka
+ */
+
+/*
+ * IRQs are in fact implemented a bit like signal handlers for the kernel.
+ * Naturally it's not a 1:1 relation, but there are similarities.
+ */
+
+#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/random.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/bitops.h>
+#include <asm/smp.h>
+#include <asm/pgtable.h>
+#include <asm/delay.h>
+#include <asm/irq.h>
+#include <linux/irq.h>
+
+
+unsigned int local_bh_count[NR_CPUS];
+unsigned int local_irq_count[NR_CPUS];
+
+/*
+ * Micro-access to controllers is serialized over the whole
+ * system. We never hold this lock when we call the actual
+ * IRQ handler.
+ */
+spinlock_t irq_controller_lock = SPIN_LOCK_UNLOCKED;
+/*
+ * Controller mappings for all interrupt sources:
+ */
+irq_desc_t irq_desc[NR_IRQS] = { [0 ... NR_IRQS-1] = { 0, &no_irq_type, }};
+
+/*
+ * Special irq handlers.
+ */
+
+void no_action(int cpl, void *dev_id, struct pt_regs *regs) { }
+
+/*
+ * Generic, controller-independent functions:
+ */
+
+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++) {
+ action = irq_desc[i].action;
+ if (!action)
+ continue;
+ p += sprintf(p, "%3d: ",i);
+ p += sprintf(p, "%10u ", kstat_irqs(i));
+ p += sprintf(p, " %14s", irq_desc[i].handler->typename);
+ p += sprintf(p, " %s", action->name);
+
+ for (action=action->next; action; action = action->next) {
+ p += sprintf(p, ", %s", action->name);
+ }
+ *p++ = '\n';
+ }
+ return p - buf;
+}
+
+/*
+ * This should really return information about whether
+ * we should do bottom half handling etc. Right now we
+ * end up _always_ checking the bottom half, which is a
+ * waste of time and is not what some drivers would
+ * prefer.
+ */
+int handle_IRQ_event(unsigned int irq, struct pt_regs * regs, struct irqaction * action)
+{
+ int status;
+ int cpu = smp_processor_id();
+
+ irq_enter(cpu, irq);
+
+ status = 1; /* Force the "do bottom halves" bit */
+
+ 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();
+
+ irq_exit(cpu, irq);
+
+ return status;
+}
+
+/*
+ * Generic enable/disable code: this just calls
+ * down into the PIC-specific version for the actual
+ * hardware disable after having gotten the irq
+ * controller lock.
+ */
+void disable_irq_nosync(unsigned int irq)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&irq_controller_lock, flags);
+ if (!irq_desc[irq].depth++) {
+ irq_desc[irq].status |= IRQ_DISABLED;
+ irq_desc[irq].handler->disable(irq);
+ }
+ spin_unlock_irqrestore(&irq_controller_lock, flags);
+}
+
+/*
+ * Synchronous version of the above, making sure the IRQ is
+ * no longer running on any other IRQ..
+ */
+void disable_irq(unsigned int irq)
+{
+ disable_irq_nosync(irq);
+
+ if (!local_irq_count[smp_processor_id()]) {
+ do {
+ barrier();
+ } while (irq_desc[irq].status & IRQ_INPROGRESS);
+ }
+}
+
+void enable_irq(unsigned int irq)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&irq_controller_lock, flags);
+ switch (irq_desc[irq].depth) {
+ case 1: {
+ unsigned int status = irq_desc[irq].status & ~IRQ_DISABLED;
+ irq_desc[irq].status = status;
+ if ((status & (IRQ_PENDING | IRQ_REPLAY)) == IRQ_PENDING) {
+ irq_desc[irq].status = status | IRQ_REPLAY;
+ hw_resend_irq(irq_desc[irq].handler,irq);
+ }
+ irq_desc[irq].handler->enable(irq);
+ /* fall-through */
+ }
+ default:
+ irq_desc[irq].depth--;
+ break;
+ case 0:
+ printk("enable_irq() unbalanced from %p\n",
+ __builtin_return_address(0));
+ }
+ spin_unlock_irqrestore(&irq_controller_lock, flags);
+}
+
+/*
+ * do_IRQ handles all normal device IRQ's.
+ */
+asmlinkage int do_IRQ(unsigned long r4, unsigned long r5,
+ unsigned long r6, unsigned long r7,
+ struct pt_regs regs)
+{
+ /*
+ * We ack quickly, we don't want the irq controller
+ * thinking we're snobs just because some other CPU has
+ * disabled global interrupts (we have already done the
+ * INT_ACK cycles, it's too late to try to pretend to the
+ * controller that we aren't taking the interrupt).
+ *
+ * 0 return value means that this irq is already being
+ * handled by some other CPU. (or is disabled)
+ */
+ int irq;
+ int cpu = smp_processor_id();
+ irq_desc_t *desc;
+ struct irqaction * action;
+ unsigned int status;
+
+ /* Get IRQ number */
+ asm volatile("stc r2_bank,%0\n\t"
+ "shlr2 %0\n\t"
+ "shlr2 %0\n\t"
+ "shlr %0\n\t"
+ "add #-16,%0\n\t"
+ :"=z" (irq));
+
+ kstat.irqs[cpu][irq]++;
+ desc = irq_desc + irq;
+ spin_lock(&irq_controller_lock);
+ irq_desc[irq].handler->ack(irq);
+ /*
+ REPLAY is when Linux resends an IRQ that was dropped earlier
+ WAITING is used by probe to mark irqs that are being tested
+ */
+ status = desc->status & ~(IRQ_REPLAY | IRQ_WAITING);
+ status |= IRQ_PENDING; /* we _want_ to handle it */
+
+ /*
+ * If the IRQ is disabled for whatever reason, we cannot
+ * use the action we have.
+ */
+ action = NULL;
+ if (!(status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
+ action = desc->action;
+ status &= ~IRQ_PENDING; /* we commit to handling */
+ status |= IRQ_INPROGRESS; /* we are handling it */
+ }
+ desc->status = status;
+ spin_unlock(&irq_controller_lock);
+
+ /*
+ * If there is no IRQ handler or it was disabled, exit early.
+ Since we set PENDING, if another processor is handling
+ a different instance of this same irq, the other processor
+ will take care of it.
+ */
+ if (!action)
+ return 1;
+
+ /*
+ * Edge triggered interrupts need to remember
+ * pending events.
+ * This applies to any hw interrupts that allow a second
+ * instance of the same irq to arrive while we are in do_IRQ
+ * or in the handler. But the code here only handles the _second_
+ * instance of the irq, not the third or fourth. So it is mostly
+ * useful for irq hardware that does not mask cleanly in an
+ * SMP environment.
+ */
+ for (;;) {
+ handle_IRQ_event(irq, &regs, action);
+ spin_lock(&irq_controller_lock);
+
+ if (!(desc->status & IRQ_PENDING))
+ break;
+ desc->status &= ~IRQ_PENDING;
+ spin_unlock(&irq_controller_lock);
+ }
+ desc->status &= ~IRQ_INPROGRESS;
+ if (!(desc->status & IRQ_DISABLED)){
+ irq_desc[irq].handler->end(irq);
+ }
+ spin_unlock(&irq_controller_lock);
+
+ /*
+ * This should be conditional: we should really get
+ * a return code from the irq handler to tell us
+ * whether the handler wants us to do software bottom
+ * half handling or not..
+ */
+ if (1) {
+ if (bh_active & bh_mask)
+ do_bottom_half();
+ }
+ return 1;
+}
+
+int request_irq(unsigned int irq,
+ void (*handler)(int, void *, struct pt_regs *),
+ unsigned long irqflags,
+ const char * devname,
+ void *dev_id)
+{
+ int retval;
+ struct irqaction * action;
+
+ if (irq >= NR_IRQS)
+ return -EINVAL;
+ if (!handler)
+ return -EINVAL;
+
+ action = (struct irqaction *)
+ kmalloc(sizeof(struct irqaction), GFP_KERNEL);
+ if (!action)
+ return -ENOMEM;
+
+ action->handler = handler;
+ action->flags = irqflags;
+ action->mask = 0;
+ action->name = devname;
+ action->next = NULL;
+ action->dev_id = dev_id;
+
+ retval = setup_irq(irq, action);
+ if (retval)
+ kfree(action);
+ return retval;
+}
+
+void free_irq(unsigned int irq, void *dev_id)
+{
+ struct irqaction **p;
+ unsigned long flags;
+
+ if (irq >= NR_IRQS)
+ return;
+
+ spin_lock_irqsave(&irq_controller_lock,flags);
+ p = &irq_desc[irq].action;
+ for (;;) {
+ struct irqaction * action = *p;
+ if (action) {
+ struct irqaction **pp = p;
+ p = &action->next;
+ if (action->dev_id != dev_id)
+ continue;
+
+ /* Found it - now remove it from the list of entries */
+ *pp = action->next;
+ if (irq_desc[irq].action)
+ break;
+ irq_desc[irq].status |= IRQ_DISABLED;
+ irq_desc[irq].handler->shutdown(irq);
+ break;
+ }
+ printk("Trying to free free IRQ%d\n",irq);
+ break;
+ }
+ spin_unlock_irqrestore(&irq_controller_lock,flags);
+}
+
+/*
+ * IRQ autodetection code..
+ *
+ * This depends on the fact that any interrupt that
+ * comes in on to an unassigned handler will get stuck
+ * with "IRQ_WAITING" cleared and the interrupt
+ * disabled.
+ */
+unsigned long probe_irq_on(void)
+{
+ unsigned int i;
+ unsigned long delay;
+
+ /*
+ * first, enable any unassigned irqs
+ */
+ spin_lock_irq(&irq_controller_lock);
+ for (i = NR_IRQS-1; i > 0; i--) {
+ if (!irq_desc[i].action) {
+ irq_desc[i].status |= IRQ_AUTODETECT | IRQ_WAITING;
+ if(irq_desc[i].handler->startup(i))
+ irq_desc[i].status |= IRQ_PENDING;
+ }
+ }
+ spin_unlock_irq(&irq_controller_lock);
+
+ /*
+ * Wait for spurious interrupts to trigger
+ */
+ for (delay = jiffies + HZ/10; time_after(delay, jiffies); )
+ /* about 100ms delay */ synchronize_irq();
+
+ /*
+ * Now filter out any obviously spurious interrupts
+ */
+ spin_lock_irq(&irq_controller_lock);
+ for (i=0; i<NR_IRQS; i++) {
+ unsigned int status = irq_desc[i].status;
+
+ if (!(status & IRQ_AUTODETECT))
+ continue;
+
+ /* It triggered already - consider it spurious. */
+ if (!(status & IRQ_WAITING)) {
+ irq_desc[i].status = status & ~IRQ_AUTODETECT;
+ irq_desc[i].handler->shutdown(i);
+ }
+ }
+ spin_unlock_irq(&irq_controller_lock);
+
+ return 0x12345678;
+}
+
+int probe_irq_off(unsigned long unused)
+{
+ int i, irq_found, nr_irqs;
+
+ if (unused != 0x12345678)
+ printk("Bad IRQ probe from %lx\n", (&unused)[-1]);
+
+ nr_irqs = 0;
+ irq_found = 0;
+ spin_lock_irq(&irq_controller_lock);
+ for (i=0; i<NR_IRQS; i++) {
+ unsigned int status = irq_desc[i].status;
+
+ if (!(status & IRQ_AUTODETECT))
+ continue;
+
+ if (!(status & IRQ_WAITING)) {
+ if (!nr_irqs)
+ irq_found = i;
+ nr_irqs++;
+ }
+ irq_desc[i].status = status & ~IRQ_AUTODETECT;
+ irq_desc[i].handler->shutdown(i);
+ }
+ spin_unlock_irq(&irq_controller_lock);
+
+ if (nr_irqs > 1)
+ irq_found = -irq_found;
+ return irq_found;
+}
+
+int setup_irq(unsigned int irq, struct irqaction * new)
+{
+ int shared = 0;
+ struct irqaction *old, **p;
+ unsigned long flags;
+
+ /*
+ * Some drivers like serial.c use request_irq() heavily,
+ * so we have to be careful not to interfere with a
+ * running system.
+ */
+ if (new->flags & SA_SAMPLE_RANDOM) {
+ /*
+ * This function might sleep, we want to call it first,
+ * outside of the atomic block.
+ * Yes, this might clear the entropy pool if the wrong
+ * driver is attempted to be loaded, without actually
+ * installing a new handler, but is this really a problem,
+ * only the sysadmin is able to do this.
+ */
+ rand_initialize_irq(irq);
+ }
+
+ /*
+ * The following block of code has to be executed atomically
+ */
+ spin_lock_irqsave(&irq_controller_lock,flags);
+ p = &irq_desc[irq].action;
+ if ((old = *p) != NULL) {
+ /* Can't share interrupts unless both agree to */
+ if (!(old->flags & new->flags & SA_SHIRQ)) {
+ spin_unlock_irqrestore(&irq_controller_lock,flags);
+ return -EBUSY;
+ }
+
+ /* add new interrupt at end of irq queue */
+ do {
+ p = &old->next;
+ old = *p;
+ } while (old);
+ shared = 1;
+ }
+
+ *p = new;
+
+ if (!shared) {
+ irq_desc[irq].depth = 0;
+ irq_desc[irq].status &= ~IRQ_DISABLED;
+ irq_desc[irq].handler->startup(irq);
+ }
+ spin_unlock_irqrestore(&irq_controller_lock,flags);
+ return 0;
+}
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