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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] [LINUX] Only trigger unhandled irq path if irq is not shared across
# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 6fb0d5ad63d74ef272d1f1754b9eabd83000577e
# Parent 8c64169a05d3fda5d0b3792edd7beaea18c2ab83
[LINUX] Only trigger unhandled irq path if irq is not shared across
multiple guests (another guest may have handled the interrupt).
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
linux-2.6-xen-sparse/drivers/xen/Kconfig | 4
linux-2.6-xen-sparse/drivers/xen/core/evtchn.c | 7
linux-2.6-xen-sparse/include/linux/interrupt.h | 301 +++++++++++++++++++++++++
linux-2.6-xen-sparse/kernel/irq/spurious.c | 206 +++++++++++++++++
4 files changed, 518 insertions(+)
diff -r 8c64169a05d3 -r 6fb0d5ad63d7 linux-2.6-xen-sparse/drivers/xen/Kconfig
--- a/linux-2.6-xen-sparse/drivers/xen/Kconfig Thu Jun 08 09:52:04 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/Kconfig Thu Jun 08 10:11:04 2006 +0100
@@ -224,6 +224,10 @@ config HAVE_ARCH_DEV_ALLOC_SKB
bool
default y
+config HAVE_IRQ_IGNORE_UNHANDLED
+ bool
+ default y
+
config NO_IDLE_HZ
bool
default y
diff -r 8c64169a05d3 -r 6fb0d5ad63d7
linux-2.6-xen-sparse/drivers/xen/core/evtchn.c
--- a/linux-2.6-xen-sparse/drivers/xen/core/evtchn.c Thu Jun 08 09:52:04
2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/core/evtchn.c Thu Jun 08 10:11:04
2006 +0100
@@ -678,6 +678,13 @@ static struct hw_interrupt_type pirq_typ
set_affinity_irq
};
+int irq_ignore_unhandled(unsigned int irq)
+{
+ struct physdev_irq_status_query irq_status = { .irq = irq };
+ (void)HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status);
+ return !!(irq_status.flags & XENIRQSTAT_shared);
+}
+
void resend_irq_on_evtchn(struct hw_interrupt_type *h, unsigned int i)
{
int evtchn = evtchn_from_irq(i);
diff -r 8c64169a05d3 -r 6fb0d5ad63d7
linux-2.6-xen-sparse/include/linux/interrupt.h
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/linux-2.6-xen-sparse/include/linux/interrupt.h Thu Jun 08 10:11:04
2006 +0100
@@ -0,0 +1,301 @@
+/* interrupt.h */
+#ifndef _LINUX_INTERRUPT_H
+#define _LINUX_INTERRUPT_H
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/linkage.h>
+#include <linux/bitops.h>
+#include <linux/preempt.h>
+#include <linux/cpumask.h>
+#include <linux/hardirq.h>
+#include <linux/sched.h>
+#include <asm/atomic.h>
+#include <asm/ptrace.h>
+#include <asm/system.h>
+
+/*
+ * For 2.4.x compatibility, 2.4.x can use
+ *
+ * typedef void irqreturn_t;
+ * #define IRQ_NONE
+ * #define IRQ_HANDLED
+ * #define IRQ_RETVAL(x)
+ *
+ * To mix old-style and new-style irq handler returns.
+ *
+ * IRQ_NONE means we didn't handle it.
+ * IRQ_HANDLED means that we did have a valid interrupt and handled it.
+ * IRQ_RETVAL(x) selects on the two depending on x being non-zero (for handled)
+ */
+typedef int irqreturn_t;
+
+#define IRQ_NONE (0)
+#define IRQ_HANDLED (1)
+#define IRQ_RETVAL(x) ((x) != 0)
+
+struct irqaction {
+ irqreturn_t (*handler)(int, void *, struct pt_regs *);
+ unsigned long flags;
+ cpumask_t mask;
+ const char *name;
+ void *dev_id;
+ struct irqaction *next;
+ int irq;
+ struct proc_dir_entry *dir;
+};
+
+extern irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs);
+extern int request_irq(unsigned int,
+ irqreturn_t (*handler)(int, void *, struct pt_regs *),
+ unsigned long, const char *, void *);
+extern void free_irq(unsigned int, void *);
+
+
+#ifdef CONFIG_GENERIC_HARDIRQS
+extern void disable_irq_nosync(unsigned int irq);
+extern void disable_irq(unsigned int irq);
+extern void enable_irq(unsigned int irq);
+#endif
+
+#ifdef CONFIG_HAVE_IRQ_IGNORE_UNHANDLED
+int irq_ignore_unhandled(unsigned int irq);
+#else
+#define irq_ignore_unhandled(irq) 0
+#endif
+
+#ifndef __ARCH_SET_SOFTIRQ_PENDING
+#define set_softirq_pending(x) (local_softirq_pending() = (x))
+#define or_softirq_pending(x) (local_softirq_pending() |= (x))
+#endif
+
+/*
+ * Temporary defines for UP kernels, until all code gets fixed.
+ */
+#ifndef CONFIG_SMP
+static inline void __deprecated cli(void)
+{
+ local_irq_disable();
+}
+static inline void __deprecated sti(void)
+{
+ local_irq_enable();
+}
+static inline void __deprecated save_flags(unsigned long *x)
+{
+ local_save_flags(*x);
+}
+#define save_flags(x) save_flags(&x)
+static inline void __deprecated restore_flags(unsigned long x)
+{
+ local_irq_restore(x);
+}
+
+static inline void __deprecated save_and_cli(unsigned long *x)
+{
+ local_irq_save(*x);
+}
+#define save_and_cli(x) save_and_cli(&x)
+#endif /* CONFIG_SMP */
+
+/* SoftIRQ primitives. */
+#define local_bh_disable() \
+ do { add_preempt_count(SOFTIRQ_OFFSET); barrier(); } while (0)
+#define __local_bh_enable() \
+ do { barrier(); sub_preempt_count(SOFTIRQ_OFFSET); } while (0)
+
+extern void local_bh_enable(void);
+
+/* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
+ frequency threaded job scheduling. For almost all the purposes
+ tasklets are more than enough. F.e. all serial device BHs et
+ al. should be converted to tasklets, not to softirqs.
+ */
+
+enum
+{
+ HI_SOFTIRQ=0,
+ TIMER_SOFTIRQ,
+ NET_TX_SOFTIRQ,
+ NET_RX_SOFTIRQ,
+ BLOCK_SOFTIRQ,
+ TASKLET_SOFTIRQ
+};
+
+/* softirq mask and active fields moved to irq_cpustat_t in
+ * asm/hardirq.h to get better cache usage. KAO
+ */
+
+struct softirq_action
+{
+ void (*action)(struct softirq_action *);
+ void *data;
+};
+
+asmlinkage void do_softirq(void);
+extern void open_softirq(int nr, void (*action)(struct softirq_action*), void
*data);
+extern void softirq_init(void);
+#define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); }
while (0)
+extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
+extern void FASTCALL(raise_softirq(unsigned int nr));
+
+
+/* Tasklets --- multithreaded analogue of BHs.
+
+ Main feature differing them of generic softirqs: tasklet
+ is running only on one CPU simultaneously.
+
+ Main feature differing them of BHs: different tasklets
+ may be run simultaneously on different CPUs.
+
+ Properties:
+ * If tasklet_schedule() is called, then tasklet is guaranteed
+ to be executed on some cpu at least once after this.
+ * If the tasklet is already scheduled, but its excecution is still not
+ started, it will be executed only once.
+ * If this tasklet is already running on another CPU (or schedule is called
+ from tasklet itself), it is rescheduled for later.
+ * Tasklet is strictly serialized wrt itself, but not
+ wrt another tasklets. If client needs some intertask synchronization,
+ he makes it with spinlocks.
+ */
+
+struct tasklet_struct
+{
+ struct tasklet_struct *next;
+ unsigned long state;
+ atomic_t count;
+ void (*func)(unsigned long);
+ unsigned long data;
+};
+
+#define DECLARE_TASKLET(name, func, data) \
+struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
+
+#define DECLARE_TASKLET_DISABLED(name, func, data) \
+struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
+
+
+enum
+{
+ TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
+ TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
+};
+
+#ifdef CONFIG_SMP
+static inline int tasklet_trylock(struct tasklet_struct *t)
+{
+ return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
+}
+
+static inline void tasklet_unlock(struct tasklet_struct *t)
+{
+ smp_mb__before_clear_bit();
+ clear_bit(TASKLET_STATE_RUN, &(t)->state);
+}
+
+static inline void tasklet_unlock_wait(struct tasklet_struct *t)
+{
+ while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
+}
+#else
+#define tasklet_trylock(t) 1
+#define tasklet_unlock_wait(t) do { } while (0)
+#define tasklet_unlock(t) do { } while (0)
+#endif
+
+extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
+
+static inline void tasklet_schedule(struct tasklet_struct *t)
+{
+ if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
+ __tasklet_schedule(t);
+}
+
+extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
+
+static inline void tasklet_hi_schedule(struct tasklet_struct *t)
+{
+ if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
+ __tasklet_hi_schedule(t);
+}
+
+
+static inline void tasklet_disable_nosync(struct tasklet_struct *t)
+{
+ atomic_inc(&t->count);
+ smp_mb__after_atomic_inc();
+}
+
+static inline void tasklet_disable(struct tasklet_struct *t)
+{
+ tasklet_disable_nosync(t);
+ tasklet_unlock_wait(t);
+ smp_mb();
+}
+
+static inline void tasklet_enable(struct tasklet_struct *t)
+{
+ smp_mb__before_atomic_dec();
+ atomic_dec(&t->count);
+}
+
+static inline void tasklet_hi_enable(struct tasklet_struct *t)
+{
+ smp_mb__before_atomic_dec();
+ atomic_dec(&t->count);
+}
+
+extern void tasklet_kill(struct tasklet_struct *t);
+extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
+extern void tasklet_init(struct tasklet_struct *t,
+ void (*func)(unsigned long), unsigned long data);
+
+/*
+ * Autoprobing for irqs:
+ *
+ * probe_irq_on() and probe_irq_off() provide robust primitives
+ * for accurate IRQ probing during kernel initialization. They are
+ * reasonably simple to use, are not "fooled" by spurious interrupts,
+ * and, unlike other attempts at IRQ probing, they do not get hung on
+ * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
+ *
+ * For reasonably foolproof probing, use them as follows:
+ *
+ * 1. clear and/or mask the device's internal interrupt.
+ * 2. sti();
+ * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
+ * 4. enable the device and cause it to trigger an interrupt.
+ * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
+ * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
+ * 7. service the device to clear its pending interrupt.
+ * 8. loop again if paranoia is required.
+ *
+ * probe_irq_on() returns a mask of allocated irq's.
+ *
+ * probe_irq_off() takes the mask as a parameter,
+ * and returns the irq number which occurred,
+ * or zero if none occurred, or a negative irq number
+ * if more than one irq occurred.
+ */
+
+#if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
+static inline unsigned long probe_irq_on(void)
+{
+ return 0;
+}
+static inline int probe_irq_off(unsigned long val)
+{
+ return 0;
+}
+static inline unsigned int probe_irq_mask(unsigned long val)
+{
+ return 0;
+}
+#else
+extern unsigned long probe_irq_on(void); /* returns 0 on failure */
+extern int probe_irq_off(unsigned long); /* returns 0 or negative on
failure */
+extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA
interrupts */
+#endif
+
+#endif
diff -r 8c64169a05d3 -r 6fb0d5ad63d7 linux-2.6-xen-sparse/kernel/irq/spurious.c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/linux-2.6-xen-sparse/kernel/irq/spurious.c Thu Jun 08 10:11:04
2006 +0100
@@ -0,0 +1,206 @@
+/*
+ * linux/kernel/irq/spurious.c
+ *
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains spurious interrupt handling.
+ */
+
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/interrupt.h>
+
+static int irqfixup;
+
+/*
+ * Recovery handler for misrouted interrupts.
+ */
+
+static int misrouted_irq(int irq, struct pt_regs *regs)
+{
+ int i;
+ irq_desc_t *desc;
+ int ok = 0;
+ int work = 0; /* Did we do work for a real IRQ */
+
+ for(i = 1; i < NR_IRQS; i++) {
+ struct irqaction *action;
+
+ if (i == irq) /* Already tried */
+ continue;
+ desc = &irq_desc[i];
+ spin_lock(&desc->lock);
+ action = desc->action;
+ /* Already running on another processor */
+ if (desc->status & IRQ_INPROGRESS) {
+ /*
+ * Already running: If it is shared get the other
+ * CPU to go looking for our mystery interrupt too
+ */
+ if (desc->action && (desc->action->flags & SA_SHIRQ))
+ desc->status |= IRQ_PENDING;
+ spin_unlock(&desc->lock);
+ continue;
+ }
+ /* Honour the normal IRQ locking */
+ desc->status |= IRQ_INPROGRESS;
+ spin_unlock(&desc->lock);
+ while (action) {
+ /* Only shared IRQ handlers are safe to call */
+ if (action->flags & SA_SHIRQ) {
+ if (action->handler(i, action->dev_id, regs) ==
+ IRQ_HANDLED)
+ ok = 1;
+ }
+ action = action->next;
+ }
+ local_irq_disable();
+ /* Now clean up the flags */
+ spin_lock(&desc->lock);
+ action = desc->action;
+
+ /*
+ * While we were looking for a fixup someone queued a real
+ * IRQ clashing with our walk
+ */
+
+ while ((desc->status & IRQ_PENDING) && action) {
+ /*
+ * Perform real IRQ processing for the IRQ we deferred
+ */
+ work = 1;
+ spin_unlock(&desc->lock);
+ handle_IRQ_event(i, regs, action);
+ spin_lock(&desc->lock);
+ desc->status &= ~IRQ_PENDING;
+ }
+ desc->status &= ~IRQ_INPROGRESS;
+ /*
+ * If we did actual work for the real IRQ line we must let the
+ * IRQ controller clean up too
+ */
+ if(work)
+ desc->handler->end(i);
+ spin_unlock(&desc->lock);
+ }
+ /* So the caller can adjust the irq error counts */
+ return ok;
+}
+
+/*
+ * If 99,900 of the previous 100,000 interrupts have not been handled
+ * then assume that the IRQ is stuck in some manner. Drop a diagnostic
+ * and try to turn the IRQ off.
+ *
+ * (The other 100-of-100,000 interrupts may have been a correctly
+ * functioning device sharing an IRQ with the failing one)
+ *
+ * Called under desc->lock
+ */
+
+static void
+__report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret)
+{
+ struct irqaction *action;
+
+ if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
+ printk(KERN_ERR "irq event %d: bogus return value %x\n",
+ irq, action_ret);
+ } else {
+ printk(KERN_ERR "irq %d: nobody cared (try booting with "
+ "the \"irqpoll\" option)\n", irq);
+ }
+ dump_stack();
+ printk(KERN_ERR "handlers:\n");
+ action = desc->action;
+ while (action) {
+ printk(KERN_ERR "[<%p>]", action->handler);
+ print_symbol(" (%s)",
+ (unsigned long)action->handler);
+ printk("\n");
+ action = action->next;
+ }
+}
+
+static void report_bad_irq(unsigned int irq, irq_desc_t *desc, irqreturn_t
action_ret)
+{
+ static int count = 100;
+
+ if (count > 0) {
+ count--;
+ __report_bad_irq(irq, desc, action_ret);
+ }
+}
+
+void note_interrupt(unsigned int irq, irq_desc_t *desc, irqreturn_t action_ret,
+ struct pt_regs *regs)
+{
+ if (action_ret != IRQ_HANDLED) {
+ if (!irq_ignore_unhandled(irq))
+ desc->irqs_unhandled++;
+ if (action_ret != IRQ_NONE)
+ report_bad_irq(irq, desc, action_ret);
+ }
+
+ if (unlikely(irqfixup)) {
+ /* Don't punish working computers */
+ if ((irqfixup == 2 && irq == 0) || action_ret == IRQ_NONE) {
+ int ok = misrouted_irq(irq, regs);
+ if (action_ret == IRQ_NONE)
+ desc->irqs_unhandled -= ok;
+ }
+ }
+
+ desc->irq_count++;
+ if (desc->irq_count < 100000)
+ return;
+
+ desc->irq_count = 0;
+ if (desc->irqs_unhandled > 99900) {
+ /*
+ * The interrupt is stuck
+ */
+ __report_bad_irq(irq, desc, action_ret);
+ /*
+ * Now kill the IRQ
+ */
+ printk(KERN_EMERG "Disabling IRQ #%d\n", irq);
+ desc->status |= IRQ_DISABLED;
+ desc->handler->disable(irq);
+ }
+ desc->irqs_unhandled = 0;
+}
+
+int noirqdebug;
+
+int __init noirqdebug_setup(char *str)
+{
+ noirqdebug = 1;
+ printk(KERN_INFO "IRQ lockup detection disabled\n");
+ return 1;
+}
+
+__setup("noirqdebug", noirqdebug_setup);
+
+static int __init irqfixup_setup(char *str)
+{
+ irqfixup = 1;
+ printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
+ printk(KERN_WARNING "This may impact system performance.\n");
+ return 1;
+}
+
+__setup("irqfixup", irqfixup_setup);
+
+static int __init irqpoll_setup(char *str)
+{
+ irqfixup = 2;
+ printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
+ "enabled\n");
+ printk(KERN_WARNING "This may significantly impact system "
+ "performance\n");
+ return 1;
+}
+
+__setup("irqpoll", irqpoll_setup);
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