[PATCH] genirq: convert the x86_64 architecture to irq-chips

This patch converts all the x86_64 PIC controllers layers to the new and
simpler irq-chip interrupt handling layer.

[mingo@elte.hu: The patch also enables the fasteoi handler for x86_64]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/x86_64/kernel/i8259.c

@@ -121,42 +121,15 @@ void (*interrupt[NR_IRQS])(void) = {
  * moves to arch independent land
  */
 
-DEFINE_SPINLOCK(i8259A_lock);
-
 static int i8259A_auto_eoi;
-
-static void end_8259A_irq (unsigned int irq)
-{
-	if (irq > 256) { 
-		char var;
-		printk("return %p stack %p ti %p\n", __builtin_return_address(0), &var, task_thread_info(current));
-
-		BUG(); 
-	}
-
-	if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)) &&
-	    irq_desc[irq].action)
-		enable_8259A_irq(irq);
-}
-
-#define shutdown_8259A_irq	disable_8259A_irq
-
+DEFINE_SPINLOCK(i8259A_lock);
 static void mask_and_ack_8259A(unsigned int);
 
-static unsigned int startup_8259A_irq(unsigned int irq)
-{ 
-	enable_8259A_irq(irq);
-	return 0; /* never anything pending */
-}
-
-static struct hw_interrupt_type i8259A_irq_type = {
-	.typename = "XT-PIC",
-	.startup = startup_8259A_irq,
-	.shutdown = shutdown_8259A_irq,
-	.enable = enable_8259A_irq,
-	.disable = disable_8259A_irq,
-	.ack = mask_and_ack_8259A,
-	.end = end_8259A_irq,
+static struct irq_chip i8259A_chip = {
+	.name		= "XT-PIC",
+	.mask		= disable_8259A_irq,
+	.unmask		= enable_8259A_irq,
+	.mask_ack	= mask_and_ack_8259A,
 };
 
 /*
@@ -231,7 +204,7 @@ void make_8259A_irq(unsigned int irq)
 {
 	disable_irq_nosync(irq);
 	io_apic_irqs &= ~(1<<irq);
-	irq_desc[irq].chip = &i8259A_irq_type;
+	set_irq_chip_and_handler(irq, &i8259A_chip, handle_level_irq);
 	enable_irq(irq);
 }
 
@@ -367,9 +340,9 @@ void init_8259A(int auto_eoi)
 		 * in AEOI mode we just have to mask the interrupt
 		 * when acking.
 		 */
-		i8259A_irq_type.ack = disable_8259A_irq;
+		i8259A_chip.mask_ack = disable_8259A_irq;
 	else
-		i8259A_irq_type.ack = mask_and_ack_8259A;
+		i8259A_chip.mask_ack = mask_and_ack_8259A;
 
 	udelay(100);		/* wait for 8259A to initialize */
 
@@ -464,12 +437,13 @@ void __init init_ISA_irqs (void)
 			/*
 			 * 16 old-style INTA-cycle interrupts:
 			 */
-			irq_desc[i].chip = &i8259A_irq_type;
+			set_irq_chip_and_handler(i, &i8259A_chip,
+						 handle_level_irq);
 		} else {
 			/*
 			 * 'high' PCI IRQs filled in on demand
 			 */
-			irq_desc[i].chip = &no_irq_type;
+			irq_desc[i].chip = &no_irq_chip;
 		}
 	}
 }

arch/x86_64/kernel/io_apic.c

@@ -633,8 +633,8 @@ next:
 }
 
 extern void (*interrupt[NR_IRQS])(void);
-static struct hw_interrupt_type ioapic_level_type;
-static struct hw_interrupt_type ioapic_edge_type;
+
+static struct irq_chip ioapic_chip;
 
 #define IOAPIC_AUTO	-1
 #define IOAPIC_EDGE	0
@@ -648,9 +648,11 @@ static void ioapic_register_intr(int irq, int vector, unsigned long trigger)
 
 	if ((trigger == IOAPIC_AUTO && IO_APIC_irq_trigger(irq)) ||
 			trigger == IOAPIC_LEVEL)
-		irq_desc[idx].chip = &ioapic_level_type;
+		set_irq_chip_and_handler(idx, &ioapic_chip,
+					 handle_fasteoi_irq);
 	else
-		irq_desc[idx].chip = &ioapic_edge_type;
+		set_irq_chip_and_handler(idx, &ioapic_chip,
+					 handle_edge_irq);
 	set_intr_gate(vector, interrupt[idx]);
 }
 
@@ -752,7 +754,7 @@ static void __init setup_ExtINT_IRQ0_pin(unsigned int apic, unsigned int pin, in
 	 * The timer IRQ doesn't have to know that behind the
 	 * scene we have a 8259A-master in AEOI mode ...
 	 */
-	irq_desc[0].chip = &ioapic_edge_type;
+	set_irq_chip_and_handler(0, &ioapic_chip, handle_edge_irq);
 
 	/*
 	 * Add it to the IO-APIC irq-routing table:
@@ -1185,7 +1187,7 @@ static int __init timer_irq_works(void)
  * an edge even if it isn't on the 8259A...
  */
 
-static unsigned int startup_edge_ioapic_irq(unsigned int irq)
+static unsigned int startup_ioapic_irq(unsigned int irq)
 {
 	int was_pending = 0;
 	unsigned long flags;
@@ -1202,86 +1204,21 @@ static unsigned int startup_edge_ioapic_irq(unsigned int irq)
 	return was_pending;
 }
 
-/*
- * Once we have recorded IRQ_PENDING already, we can mask the
- * interrupt for real. This prevents IRQ storms from unhandled
- * devices.
- */
-static void ack_edge_ioapic_irq(unsigned int irq)
-{
-	move_irq(irq);
-	if ((irq_desc[irq].status & (IRQ_PENDING | IRQ_DISABLED))
-					== (IRQ_PENDING | IRQ_DISABLED))
-		mask_IO_APIC_irq(irq);
-	ack_APIC_irq();
-}
-
-/*
- * Level triggered interrupts can just be masked,
- * and shutting down and starting up the interrupt
- * is the same as enabling and disabling them -- except
- * with a startup need to return a "was pending" value.
- *
- * Level triggered interrupts are special because we
- * do not touch any IO-APIC register while handling
- * them. We ack the APIC in the end-IRQ handler, not
- * in the start-IRQ-handler. Protection against reentrance
- * from the same interrupt is still provided, both by the
- * generic IRQ layer and by the fact that an unacked local
- * APIC does not accept IRQs.
- */
-static unsigned int startup_level_ioapic_irq (unsigned int irq)
-{
-	unmask_IO_APIC_irq(irq);
-
-	return 0; /* don't check for pending */
-}
-
-static void end_level_ioapic_irq (unsigned int irq)
-{
-	move_irq(irq);
-	ack_APIC_irq();
-}
-
-#ifdef CONFIG_PCI_MSI
-static unsigned int startup_edge_ioapic_vector(unsigned int vector)
-{
-	int irq = vector_to_irq(vector);
-
-	return startup_edge_ioapic_irq(irq);
-}
-
-static void ack_edge_ioapic_vector(unsigned int vector)
-{
-	int irq = vector_to_irq(vector);
-
-	move_native_irq(vector);
-	ack_edge_ioapic_irq(irq);
-}
-
-static unsigned int startup_level_ioapic_vector (unsigned int vector)
-{
-	int irq = vector_to_irq(vector);
-
-	return startup_level_ioapic_irq (irq);
-}
-
-static void end_level_ioapic_vector (unsigned int vector)
+static unsigned int startup_ioapic_vector(unsigned int vector)
 {
 	int irq = vector_to_irq(vector);
 
-	move_native_irq(vector);
-	end_level_ioapic_irq(irq);
+	return startup_ioapic_irq(irq);
 }
 
-static void mask_IO_APIC_vector (unsigned int vector)
+static void mask_ioapic_vector (unsigned int vector)
 {
 	int irq = vector_to_irq(vector);
 
 	mask_IO_APIC_irq(irq);
 }
 
-static void unmask_IO_APIC_vector (unsigned int vector)
+static void unmask_ioapic_vector (unsigned int vector)
 {
 	int irq = vector_to_irq(vector);
 
@@ -1298,10 +1235,11 @@ static void set_ioapic_affinity_vector (unsigned int vector,
 	set_ioapic_affinity_irq(irq, cpu_mask);
 }
 #endif // CONFIG_SMP
-#endif // CONFIG_PCI_MSI
 
-static int ioapic_retrigger(unsigned int irq)
+static int ioapic_retrigger_vector(unsigned int vector)
 {
+	int irq = vector_to_irq(vector);
+
 	send_IPI_self(IO_APIC_VECTOR(irq));
 
 	return 1;
@@ -1316,32 +1254,22 @@ static int ioapic_retrigger(unsigned int irq)
  * races.
  */
 
-static struct hw_interrupt_type ioapic_edge_type __read_mostly = {
-	.typename = "IO-APIC-edge",
-	.startup 	= startup_edge_ioapic,
-	.shutdown 	= shutdown_edge_ioapic,
-	.enable 	= enable_edge_ioapic,
-	.disable 	= disable_edge_ioapic,
-	.ack 		= ack_edge_ioapic,
-	.end 		= end_edge_ioapic,
-#ifdef CONFIG_SMP
-	.set_affinity = set_ioapic_affinity,
-#endif
-	.retrigger	= ioapic_retrigger,
-};
+static void ack_apic(unsigned int vector)
+{
+	ack_APIC_irq();
+}
 
-static struct hw_interrupt_type ioapic_level_type __read_mostly = {
-	.typename = "IO-APIC-level",
-	.startup 	= startup_level_ioapic,
-	.shutdown 	= shutdown_level_ioapic,
-	.enable 	= enable_level_ioapic,
-	.disable 	= disable_level_ioapic,
-	.ack 		= mask_and_ack_level_ioapic,
-	.end 		= end_level_ioapic,
+static struct irq_chip ioapic_chip __read_mostly = {
+	.name 		= "IO-APIC",
+	.startup 	= startup_ioapic_vector,
+	.mask	 	= mask_ioapic_vector,
+	.unmask	 	= unmask_ioapic_vector,
+	.ack 		= ack_apic,
+	.eoi 		= ack_apic,
 #ifdef CONFIG_SMP
-	.set_affinity = set_ioapic_affinity,
+	.set_affinity 	= set_ioapic_affinity_vector,
 #endif
-	.retrigger	= ioapic_retrigger,
+	.retrigger	= ioapic_retrigger_vector,
 };
 
 static inline void init_IO_APIC_traps(void)
@@ -1376,7 +1304,7 @@ static inline void init_IO_APIC_traps(void)
 				make_8259A_irq(irq);
 			else
 				/* Strange. Oh, well.. */
-				irq_desc[irq].chip = &no_irq_type;
+				irq_desc[irq].chip = &no_irq_chip;
 		}
 	}
 }

arch/x86_64/kernel/irq.c

@@ -74,7 +74,8 @@ int show_interrupts(struct seq_file *p, void *v)
 		for_each_online_cpu(j)
 			seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 #endif
-		seq_printf(p, " %14s", irq_desc[i].chip->typename);
+		seq_printf(p, " %8s", irq_desc[i].chip->name);
+		seq_printf(p, "-%s", handle_irq_name(irq_desc[i].handle_irq));
 
 		seq_printf(p, "  %s", action->name);
 		for (action=action->next; action; action = action->next)
@@ -117,7 +118,7 @@ asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 	stack_overflow_check(regs);
 #endif
-	__do_IRQ(irq, regs);
+	generic_handle_irq(irq, regs);
 	irq_exit();
 
 	return 1;

include/asm-x86_64/hw_irq.h

@@ -19,8 +19,6 @@
 #include <asm/irq.h>
 #include <linux/profile.h>
 #include <linux/smp.h>
-
-struct hw_interrupt_type;
 #endif
 
 #define NMI_VECTOR		0x02