Attachment 66049 Details for Bug 145366

[patch] Don't ack apic when disabled

bad-apic-ack (text/plain), 3.01 KB, created by Andreas Kleen on 2006-02-01 15:48:44 UTC

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Creator: Andreas Kleen

Created: 2006-02-01 15:48:44 UTC

Size: 3.01 KB

patch

obsolete

>i386/x86-64: Don't ack the APIC for bad interrupts when the APIC is not enabled
>
>It's bad juju to touch the APIC when it hasn't been enabled.
>I also moved ack_bad_irq for x86-64 out of line following i386.
>
>Cc: mingo@elte.hu
>
>Index: linux/arch/x86_64/kernel/apic.c
>===================================================================
>--- linux.orig/arch/x86_64/kernel/apic.c
>+++ linux/arch/x86_64/kernel/apic.c
>@@ -71,6 +71,26 @@ int get_maxlvt(void)
> 	return maxlvt;
> }
> 
>+/*
>+ * '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);
>+	/*
>+	 * 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 don't ack when the APIC is disabled. -AK
>+	 */
>+	if (!disable_apic)
>+		ack_APIC_irq();
>+}
>+
> void clear_local_APIC(void)
> {
> 	int maxlvt;
>Index: linux/include/asm-x86_64/hardirq.h
>===================================================================
>--- linux.orig/include/asm-x86_64/hardirq.h
>+++ linux/include/asm-x86_64/hardirq.h
>@@ -16,23 +16,6 @@
> #define set_softirq_pending(x) write_pda(__softirq_pending, (x))
> #define or_softirq_pending(x)  or_pda(__softirq_pending, (x))
> 
>-/*
>- * 'what should we do if we get a hw irq event on an illegal vector'.
>- * each architecture has to answer this themselves.
>- */
>-static inline void ack_bad_irq(unsigned int irq)
>-{
>-	printk("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.
>-	 */
>-	ack_APIC_irq();
>-#endif
>-}
>+extern void ack_bad_irq(unsigned int irq);
>+
> #endif /* __ASM_HARDIRQ_H */
>Index: linux/arch/i386/kernel/apic.c
>===================================================================
>--- linux.orig/arch/i386/kernel/apic.c
>+++ linux/arch/i386/kernel/apic.c
>@@ -75,8 +75,10 @@ void ack_bad_irq(unsigned int 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
> 	 */
>-	ack_APIC_irq();
>+	if (!cpu_has_apic)
>+		ack_APIC_irq();
> }
> 
> void __init apic_intr_init(void)
>@@ -1303,6 +1305,7 @@ int __init APIC_init_uniprocessor (void)
> 	if (!cpu_has_apic && APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
> 		printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
> 			boot_cpu_physical_apicid);
>+		clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
> 		return -1;
> 	}
>

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