x86, ioapic: Consolidate the explicit EOI code

Consolidate the io-apic EOI code in clear_IO_APIC_pin() and
eoi_ioapic_irq().

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Rafael Wysocki <rjw@novell.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: lchiquitto@novell.com
Cc: jbeulich@novell.com
Cc: yinghai@kernel.org
Link: http://lkml.kernel.org/r/20110825190657.259696697@sbsiddha-desk.sc.intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/apic/io_apic.c

@@ -581,6 +581,66 @@ static void unmask_ioapic_irq(struct irq_data *data)
 	unmask_ioapic(data->chip_data);
 }
 
+/*
+ * IO-APIC versions below 0x20 don't support EOI register.
+ * For the record, here is the information about various versions:
+ *     0Xh     82489DX
+ *     1Xh     I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant
+ *     2Xh     I/O(x)APIC which is PCI 2.2 Compliant
+ *     30h-FFh Reserved
+ *
+ * Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic
+ * version as 0x2. This is an error with documentation and these ICH chips
+ * use io-apic's of version 0x20.
+ *
+ * For IO-APIC's with EOI register, we use that to do an explicit EOI.
+ * Otherwise, we simulate the EOI message manually by changing the trigger
+ * mode to edge and then back to level, with RTE being masked during this.
+ */
+static void __eoi_ioapic_pin(int apic, int pin, int vector, struct irq_cfg *cfg)
+{
+	if (mpc_ioapic_ver(apic) >= 0x20) {
+		/*
+		 * Intr-remapping uses pin number as the virtual vector
+		 * in the RTE. Actual vector is programmed in
+		 * intr-remapping table entry. Hence for the io-apic
+		 * EOI we use the pin number.
+		 */
+		if (cfg && irq_remapped(cfg))
+			io_apic_eoi(apic, pin);
+		else
+			io_apic_eoi(apic, vector);
+	} else {
+		struct IO_APIC_route_entry entry, entry1;
+
+		entry = entry1 = __ioapic_read_entry(apic, pin);
+
+		/*
+		 * Mask the entry and change the trigger mode to edge.
+		 */
+		entry1.mask = 1;
+		entry1.trigger = IOAPIC_EDGE;
+
+		__ioapic_write_entry(apic, pin, entry1);
+
+		/*
+		 * Restore the previous level triggered entry.
+		 */
+		__ioapic_write_entry(apic, pin, entry);
+	}
+}
+
+static void eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg)
+{
+	struct irq_pin_list *entry;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&ioapic_lock, flags);
+	for_each_irq_pin(entry, cfg->irq_2_pin)
+		__eoi_ioapic_pin(entry->apic, entry->pin, cfg->vector, cfg);
+	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+}
+
 static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
 {
 	struct IO_APIC_route_entry entry;
@@ -601,6 +661,8 @@ static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
 	}
 
 	if (entry.irr) {
+		unsigned long flags;
+
 		/*
 		 * Make sure the trigger mode is set to level. Explicit EOI
 		 * doesn't clear the remote-IRR if the trigger mode is not
@@ -611,23 +673,9 @@ static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin)
 			ioapic_write_entry(apic, pin, entry);
 		}
 
-		if (mpc_ioapic_ver(apic) >= 0x20) {
-			unsigned long flags;
-
-			raw_spin_lock_irqsave(&ioapic_lock, flags);
-			io_apic_eoi(apic, entry.vector);
-			raw_spin_unlock_irqrestore(&ioapic_lock, flags);
-		} else {
-			/*
-			 * Mechanism by which we clear remote-IRR in this
-			 * case is by changing the trigger mode to edge and
-			 * back to level.
-			 */
-			entry.trigger = IOAPIC_EDGE;
-			ioapic_write_entry(apic, pin, entry);
-			entry.trigger = IOAPIC_LEVEL;
-			ioapic_write_entry(apic, pin, entry);
-		}
+		raw_spin_lock_irqsave(&ioapic_lock, flags);
+		__eoi_ioapic_pin(apic, pin, entry.vector, NULL);
+		raw_spin_unlock_irqrestore(&ioapic_lock, flags);
 	}
 
 	/*
@@ -2457,63 +2505,6 @@ static void ack_apic_edge(struct irq_data *data)
 
 atomic_t irq_mis_count;
 
-/*
- * IO-APIC versions below 0x20 don't support EOI register.
- * For the record, here is the information about various versions:
- *     0Xh     82489DX
- *     1Xh     I/OAPIC or I/O(x)APIC which are not PCI 2.2 Compliant
- *     2Xh     I/O(x)APIC which is PCI 2.2 Compliant
- *     30h-FFh Reserved
- *
- * Some of the Intel ICH Specs (ICH2 to ICH5) documents the io-apic
- * version as 0x2. This is an error with documentation and these ICH chips
- * use io-apic's of version 0x20.
- *
- * For IO-APIC's with EOI register, we use that to do an explicit EOI.
- * Otherwise, we simulate the EOI message manually by changing the trigger
- * mode to edge and then back to level, with RTE being masked during this.
-*/
-static void eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg)
-{
-	struct irq_pin_list *entry;
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&ioapic_lock, flags);
-	for_each_irq_pin(entry, cfg->irq_2_pin) {
-		if (mpc_ioapic_ver(entry->apic) >= 0x20) {
-			/*
-			 * Intr-remapping uses pin number as the virtual vector
-			 * in the RTE. Actual vector is programmed in
-			 * intr-remapping table entry. Hence for the io-apic
-			 * EOI we use the pin number.
-			 */
-			if (irq_remapped(cfg))
-				io_apic_eoi(entry->apic, entry->pin);
-			else
-				io_apic_eoi(entry->apic, cfg->vector);
-		} else {
-			struct IO_APIC_route_entry rte, rte1;
-
-			rte = rte1 =
-				__ioapic_read_entry(entry->apic, entry->pin);
-
-			/*
-			 * Mask the entry and change the trigger mode to edge.
-			 */
-			rte1.mask = 1;
-			rte1.trigger = IOAPIC_EDGE;
-
-			__ioapic_write_entry(apic, pin, rte1);
-
-			/*
-			 * Restore the previous level triggered entry.
-			 */
-			__ioapic_write_entry(apic, pin, rte);
-		}
-	}
-	raw_spin_unlock_irqrestore(&ioapic_lock, flags);
-}
-
 static void ack_apic_level(struct irq_data *data)
 {
 	struct irq_cfg *cfg = data->chip_data;