patch-2.4.6 linux/arch/sh/kernel/irq.c
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- Lines: 348
- Date:
Wed Jun 27 13:55:29 2001
- Orig file:
v2.4.5/linux/arch/sh/kernel/irq.c
- Orig date:
Fri Feb 9 11:29:44 2001
diff -u --recursive --new-file v2.4.5/linux/arch/sh/kernel/irq.c linux/arch/sh/kernel/irq.c
@@ -38,12 +38,6 @@
#include <linux/irq.h>
/*
- * 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] __cacheline_aligned =
@@ -160,14 +154,15 @@
*/
void disable_irq_nosync(unsigned int irq)
{
+ irq_desc_t *desc = irq_desc + 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_lock_irqsave(&desc->lock, flags);
+ if (!desc->depth++) {
+ desc->status |= IRQ_DISABLED;
+ desc->handler->disable(irq);
}
- spin_unlock_irqrestore(&irq_controller_lock, flags);
+ spin_unlock_irqrestore(&desc->lock, flags);
}
/*
@@ -187,28 +182,29 @@
void enable_irq(unsigned int irq)
{
+ irq_desc_t *desc = irq_desc + irq;
unsigned long flags;
- spin_lock_irqsave(&irq_controller_lock, flags);
- switch (irq_desc[irq].depth) {
+ spin_lock_irqsave(&desc->lock, flags);
+ switch (desc->depth) {
case 1: {
- unsigned int status = irq_desc[irq].status & ~IRQ_DISABLED;
- irq_desc[irq].status = status;
+ unsigned int status = desc->status & ~IRQ_DISABLED;
+ desc->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);
+ desc->status = status | IRQ_REPLAY;
+ hw_resend_irq(desc->handler,irq);
}
- irq_desc[irq].handler->enable(irq);
+ desc->handler->enable(irq);
/* fall-through */
}
default:
- irq_desc[irq].depth--;
+ desc->depth--;
break;
case 0:
printk("enable_irq() unbalanced from %p\n",
__builtin_return_address(0));
}
- spin_unlock_irqrestore(&irq_controller_lock, flags);
+ spin_unlock_irqrestore(&desc->lock, flags);
}
/*
@@ -245,7 +241,7 @@
kstat.irqs[cpu][irq]++;
desc = irq_desc + irq;
- spin_lock(&irq_controller_lock);
+ spin_lock(&desc->lock);
desc->handler->ack(irq);
/*
REPLAY is when Linux resends an IRQ that was dropped earlier
@@ -265,7 +261,6 @@
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.
@@ -274,7 +269,7 @@
will take care of it.
*/
if (!action)
- return 1;
+ goto out;
/*
* Edge triggered interrupts need to remember
@@ -287,23 +282,24 @@
* SMP environment.
*/
for (;;) {
+ spin_unlock(&desc->lock);
handle_IRQ_event(irq, ®s, action);
- spin_lock(&irq_controller_lock);
+ spin_lock(&desc->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))
- desc->handler->end(irq);
- spin_unlock(&irq_controller_lock);
+out:
+ /*
+ * The ->end() handler has to deal with interrupts which got
+ * disabled while the handler was running.
+ */
+ desc->handler->end(irq);
+ spin_unlock(&desc->lock);
-#if 0
- __sti();
-#endif
- if (softirq_active(cpu)&softirq_mask(cpu))
+ if (softirq_pending(cpu))
do_softirq();
return 1;
}
@@ -342,14 +338,16 @@
void free_irq(unsigned int irq, void *dev_id)
{
+ irq_desc_t *desc;
struct irqaction **p;
unsigned long flags;
if (irq >= ACTUAL_NR_IRQS)
return;
- spin_lock_irqsave(&irq_controller_lock,flags);
- p = &irq_desc[irq].action;
+ desc = irq_desc + irq;
+ spin_lock_irqsave(&desc->lock,flags);
+ p = &desc->action;
for (;;) {
struct irqaction * action = *p;
if (action) {
@@ -360,20 +358,22 @@
/* Found it - now remove it from the list of entries */
*pp = action->next;
- if (!irq_desc[irq].action) {
- irq_desc[irq].status |= IRQ_DISABLED;
- irq_desc[irq].handler->shutdown(irq);
+ if (!desc->action) {
+ desc->status |= IRQ_DISABLED;
+ desc->handler->shutdown(irq);
}
- spin_unlock_irqrestore(&irq_controller_lock,flags);
+ spin_unlock_irqrestore(&desc->lock,flags);
kfree(action);
return;
}
printk("Trying to free free IRQ%d\n",irq);
- spin_unlock_irqrestore(&irq_controller_lock,flags);
+ spin_unlock_irqrestore(&desc->lock,flags);
return;
}
}
+static DECLARE_MUTEX(probe_sem);
+
/*
* IRQ autodetection code..
*
@@ -385,21 +385,44 @@
unsigned long probe_irq_on(void)
{
unsigned int i;
- unsigned long delay;
+ irq_desc_t *desc;
unsigned long val;
+ unsigned long delay;
+
+ down(&probe_sem);
+ /*
+ * something may have generated an irq long ago and we want to
+ * flush such a longstanding irq before considering it as spurious.
+ */
+ for (i = NR_IRQS-1; i > 0; i--) {
+ desc = irq_desc + i;
+
+ spin_lock_irq(&desc->lock);
+ if (!desc->action)
+ desc->handler->startup(i);
+ spin_unlock_irq(&desc->lock);
+ }
+
+ /* Wait for longstanding interrupts to trigger. */
+ for (delay = jiffies + HZ/50; time_after(delay, jiffies); )
+ /* about 20ms delay */ synchronize_irq();
/*
- * first, enable any unassigned irqs
+ * enable any unassigned irqs
+ * (we must startup again here because if a longstanding irq
+ * happened in the previous stage, it may have masked itself)
*/
- 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;
+ desc = irq_desc + i;
+
+ spin_lock_irq(&desc->lock);
+ if (!desc->action) {
+ desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
+ if (desc->handler->startup(i))
+ desc->status |= IRQ_PENDING;
}
+ spin_unlock_irq(&desc->lock);
}
- spin_unlock_irq(&irq_controller_lock);
/*
* Wait for spurious interrupts to trigger
@@ -411,23 +434,25 @@
* Now filter out any obviously spurious interrupts
*/
val = 0;
- spin_lock_irq(&irq_controller_lock);
for (i=0; i<NR_IRQS; i++) {
- unsigned int status = irq_desc[i].status;
+ desc = irq_desc + i;
+ unsigned int status;
- if (!(status & IRQ_AUTODETECT))
- continue;
+ spin_lock_irq(&desc->lock);
+ status = desc->status;
- /* It triggered already - consider it spurious. */
- if (!(status & IRQ_WAITING)) {
- irq_desc[i].status = status & ~IRQ_AUTODETECT;
- irq_desc[i].handler->shutdown(i);
+ if (status & IRQ_AUTODETECT) {
+ /* It triggered already - consider it spurious. */
+ if (!(status & IRQ_WAITING)) {
+ desc->status = status & ~IRQ_AUTODETECT;
+ desc->handler->shutdown(i);
+ } else
+ if (i < 32)
+ val |= 1 << i;
}
-
- if (i < 32)
- val |= 1 << i;
+ spin_unlock_irq(&desc->lock);
}
- spin_unlock_irq(&irq_controller_lock);
+ spin_unlock_irq(&desc->lock);
return val;
}
@@ -438,22 +463,25 @@
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;
+ irq_desc_t *desc = irq_desc + i;
+ unsigned int status;
- if (!(status & IRQ_AUTODETECT))
- continue;
+ spin_lock_irq(&desc->lock);
+ status = desc->status;
- if (!(status & IRQ_WAITING)) {
- if (!nr_irqs)
- irq_found = i;
- nr_irqs++;
+ if (status & IRQ_AUTODETECT) {
+ if (!(status & IRQ_WAITING)) {
+ if (!nr_irqs)
+ irq_found = i;
+ nr_irqs++;
+ }
+ desc->status = status & ~IRQ_AUTODETECT;
+ desc->handler->shutdown(i);
}
- irq_desc[i].status = status & ~IRQ_AUTODETECT;
- irq_desc[i].handler->shutdown(i);
+ spin_unlock_irq(&desc->lock);
}
- spin_unlock_irq(&irq_controller_lock);
+ up(&probe_sem);
if (nr_irqs > 1)
irq_found = -irq_found;
@@ -465,6 +493,7 @@
int shared = 0;
struct irqaction *old, **p;
unsigned long flags;
+ irq_desc_t *desc = irq_desc + irq;
/*
* Some drivers like serial.c use request_irq() heavily,
@@ -486,12 +515,12 @@
/*
* The following block of code has to be executed atomically
*/
- spin_lock_irqsave(&irq_controller_lock,flags);
- p = &irq_desc[irq].action;
+ spin_lock_irqsave(&desc->lock,flags);
+ p = &desc->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);
+ spin_unlock_irqrestore(&desc->lock,flags);
return -EBUSY;
}
@@ -506,11 +535,11 @@
*p = new;
if (!shared) {
- irq_desc[irq].depth = 0;
- irq_desc[irq].status &= ~IRQ_DISABLED;
- irq_desc[irq].handler->startup(irq);
+ desc->depth = 0;
+ desc->status &= ~IRQ_DISABLED;
+ desc->handler->startup(irq);
}
- spin_unlock_irqrestore(&irq_controller_lock,flags);
+ spin_unlock_irqrestore(&desc->lock,flags);
return 0;
}
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