[PATCH] i386, apic: clean up the APIC code
The apic code is quite unstructured and missing a lot of comments.
- Restructure the code into helper functions, timer, setup/shutdown,
interrupt and power management blocks.
- Fixup comments.
- Namespace fixups
- Inline helpers for version and is_integrated
- Combine the ack_bad_irq functions
No functional changes.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
index 5785d84..0f2ca590 100644
--- a/arch/i386/kernel/irq.c
+++ b/arch/i386/kernel/irq.c
@@ -10,7 +10,6 @@
* io_apic.c.)
*/
-#include <asm/uaccess.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
@@ -21,19 +20,34 @@
#include <asm/idle.h>
+#include <asm/apic.h>
+#include <asm/uaccess.h>
+
DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp;
EXPORT_PER_CPU_SYMBOL(irq_stat);
-#ifndef CONFIG_X86_LOCAL_APIC
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
* each architecture has to answer this themselves.
*/
void ack_bad_irq(unsigned int irq)
{
- printk("unexpected IRQ trap at vector %02x\n", irq);
-}
+ printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ /*
+ * Currently unexpected vectors happen only on SMP and APIC.
+ * We _must_ ack these because every local APIC has only N
+ * irq slots per priority level, and a 'hanging, unacked' IRQ
+ * holds up an irq slot - in excessive cases (when multiple
+ * unexpected vectors occur) that might lock up the APIC
+ * completely.
+ * But only ack when the APIC is enabled -AK
+ */
+ if (cpu_has_apic)
+ ack_APIC_irq();
#endif
+}
#ifdef CONFIG_4KSTACKS
/*