[PATCH] generic irq subsystem: x86_64 port

x86_64 port of generic hardirq handling.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/Kconfig

@@ -329,6 +329,12 @@ config X86_MCE
 
 endmenu
 
+#
+# Use the generic interrupt handling code in kernel/hardirq.c:
+#
+config GENERIC_HARDIRQS
+	bool
+	default y
 
 menu "Power management options"
 

include/asm-x86_64/hardirq.h

@@ -5,6 +5,7 @@
 #include <linux/threads.h>
 #include <linux/irq.h>
 #include <asm/pda.h>
+#include <asm/apic.h>
 
 #define __ARCH_IRQ_STAT 1
 
@@ -15,47 +16,24 @@
 #include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */
 
 /*
- * We put the hardirq and softirq counter into the preemption
- * counter. The bitmask has the following meaning:
- *
- * - bits 0-7 are the preemption count (max preemption depth: 256)
- * - bits 8-15 are the softirq count (max # of softirqs: 256)
- * - bits 16-23 are the hardirq count (max # of hardirqs: 256)
- *
- * - ( bit 26 is the PREEMPT_ACTIVE flag. )
- *
- * PREEMPT_MASK: 0x000000ff
- * HARDIRQ_MASK: 0x0000ff00
- * SOFTIRQ_MASK: 0x00ff0000
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themselves.
  */
-
-#define PREEMPT_BITS	8
-#define SOFTIRQ_BITS	8
-#define HARDIRQ_BITS	8
-
-#define PREEMPT_SHIFT	0
-#define SOFTIRQ_SHIFT	(PREEMPT_SHIFT + PREEMPT_BITS)
-#define HARDIRQ_SHIFT	(SOFTIRQ_SHIFT + SOFTIRQ_BITS)
-
-/*
- * The hardirq mask has to be large enough to have
- * space for potentially all IRQ sources in the system
- * nesting on a single CPU:
+static inline void ack_bad_irq(unsigned int irq)
+{
+#ifdef CONFIG_X86
+	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.
 	 */
-#if (1 << HARDIRQ_BITS) < NR_IRQS
-# error HARDIRQ_BITS is too low!
+	ack_APIC_irq();
 #endif
-
-#define nmi_enter()		(irq_enter())
-#define nmi_exit()		(preempt_count() -= HARDIRQ_OFFSET)
-
-#define irq_enter()		(preempt_count() += HARDIRQ_OFFSET)
-#define irq_exit()							\
-do {									\
-		preempt_count() -= IRQ_EXIT_OFFSET;			\
-		if (!in_interrupt() && softirq_pending(smp_processor_id())) \
-			do_softirq();					\
-		preempt_enable_no_resched();				\
-} while (0)
-
+#endif
+}
 #endif /* __ASM_HARDIRQ_H */

include/asm-x86_64/irq.h

@@ -44,11 +44,6 @@ static __inline__ int irq_canonicalize(int irq)
 	return ((irq == 2) ? 9 : irq);
 }
 
-extern void disable_irq(unsigned int);
-extern void disable_irq_nosync(unsigned int);
-extern void enable_irq(unsigned int);
-extern int can_request_irq(unsigned int, unsigned long flags);
-
 #ifdef CONFIG_X86_LOCAL_APIC
 #define ARCH_HAS_NMI_WATCHDOG		/* See include/linux/nmi.h */
 #endif