x86, pic: Make use of legacy_pic abstraction

This patch replaces legacy PIC-related global variable and functions
with the new legacy_pic abstraction.

Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80D04@orsmsx508.amr.corp.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index dfca210..94f22b1 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1390,7 +1390,7 @@
 	}
 
 	local_irq_save(flags);
-	mask_8259A();
+	legacy_pic->mask_all();
 	mask_IO_APIC_setup(ioapic_entries);
 
 	if (dmar_table_init_ret)
@@ -1422,7 +1422,7 @@
 nox2apic:
 	if (!ret) /* IR enabling failed */
 		restore_IO_APIC_setup(ioapic_entries);
-	unmask_8259A();
+	legacy_pic->restore_mask();
 	local_irq_restore(flags);
 
 out:
@@ -2018,7 +2018,7 @@
 		}
 
 		mask_IO_APIC_setup(ioapic_entries);
-		mask_8259A();
+		legacy_pic->mask_all();
 	}
 
 	if (x2apic_mode)
@@ -2062,7 +2062,7 @@
 
 	if (intr_remapping_enabled) {
 		reenable_intr_remapping(x2apic_mode);
-		unmask_8259A();
+		legacy_pic->restore_mask();
 		restore_IO_APIC_setup(ioapic_entries);
 		free_ioapic_entries(ioapic_entries);
 	}
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 75265ab..1704cd8 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -94,8 +94,6 @@
 /* # of MP IRQ source entries */
 int mp_irq_entries;
 
-/* Number of legacy interrupts */
-static int nr_legacy_irqs __read_mostly = NR_IRQS_LEGACY;
 /* GSI interrupts */
 static int nr_irqs_gsi = NR_IRQS_LEGACY;
 
@@ -147,7 +145,6 @@
 
 void __init io_apic_disable_legacy(void)
 {
-	nr_legacy_irqs = 0;
 	nr_irqs_gsi = 0;
 }
 
@@ -164,13 +161,13 @@
 	node= cpu_to_node(boot_cpu_id);
 
 	for (i = 0; i < count; i++) {
-		if (i < nr_legacy_irqs)
+		if (i < legacy_pic->nr_legacy_irqs)
 			cfg[i].vector = IRQ0_VECTOR + i;
 		desc = irq_to_desc(i);
 		desc->chip_data = &cfg[i];
 		zalloc_cpumask_var_node(&cfg[i].domain, GFP_NOWAIT, node);
 		zalloc_cpumask_var_node(&cfg[i].old_domain, GFP_NOWAIT, node);
-		if (i < nr_legacy_irqs)
+		if (i < legacy_pic->nr_legacy_irqs)
 			cpumask_setall(cfg[i].domain);
 	}
 
@@ -850,7 +847,7 @@
  */
 static int EISA_ELCR(unsigned int irq)
 {
-	if (irq < nr_legacy_irqs) {
+	if (irq < legacy_pic->nr_legacy_irqs) {
 		unsigned int port = 0x4d0 + (irq >> 3);
 		return (inb(port) >> (irq & 7)) & 1;
 	}
@@ -1446,8 +1443,8 @@
 	}
 
 	ioapic_register_intr(irq, desc, trigger);
-	if (irq < nr_legacy_irqs)
-		disable_8259A_irq(irq);
+	if (irq < legacy_pic->nr_legacy_irqs)
+		legacy_pic->chip->mask(irq);
 
 	ioapic_write_entry(apic_id, pin, entry);
 }
@@ -1810,7 +1807,7 @@
 	unsigned int v;
 	unsigned long flags;
 
-	if (!nr_legacy_irqs)
+	if (!legacy_pic->nr_legacy_irqs)
 		return;
 
 	printk(KERN_DEBUG "\nprinting PIC contents\n");
@@ -1894,7 +1891,7 @@
 		nr_ioapic_registers[apic] = reg_01.bits.entries+1;
 	}
 
-	if (!nr_legacy_irqs)
+	if (!legacy_pic->nr_legacy_irqs)
 		return;
 
 	for(apic = 0; apic < nr_ioapics; apic++) {
@@ -1951,7 +1948,7 @@
 	 */
 	clear_IO_APIC();
 
-	if (!nr_legacy_irqs)
+	if (!legacy_pic->nr_legacy_irqs)
 		return;
 
 	/*
@@ -2184,9 +2181,9 @@
 	struct irq_cfg *cfg;
 
 	spin_lock_irqsave(&ioapic_lock, flags);
-	if (irq < nr_legacy_irqs) {
-		disable_8259A_irq(irq);
-		if (i8259A_irq_pending(irq))
+	if (irq < legacy_pic->nr_legacy_irqs) {
+		legacy_pic->chip->mask(irq);
+		if (legacy_pic->irq_pending(irq))
 			was_pending = 1;
 	}
 	cfg = irq_cfg(irq);
@@ -2719,8 +2716,8 @@
 			 * so default to an old-fashioned 8259
 			 * interrupt if we can..
 			 */
-			if (irq < nr_legacy_irqs)
-				make_8259A_irq(irq);
+			if (irq < legacy_pic->nr_legacy_irqs)
+				legacy_pic->make_irq(irq);
 			else
 				/* Strange. Oh, well.. */
 				desc->chip = &no_irq_chip;
@@ -2877,7 +2874,7 @@
 	/*
 	 * get/set the timer IRQ vector:
 	 */
-	disable_8259A_irq(0);
+	legacy_pic->chip->mask(0);
 	assign_irq_vector(0, cfg, apic->target_cpus());
 
 	/*
@@ -2890,7 +2887,7 @@
 	 * automatically.
 	 */
 	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
-	init_8259A(1);
+	legacy_pic->init(1);
 #ifdef CONFIG_X86_32
 	{
 		unsigned int ver;
@@ -2949,7 +2946,7 @@
 		if (timer_irq_works()) {
 			if (nmi_watchdog == NMI_IO_APIC) {
 				setup_nmi();
-				enable_8259A_irq(0);
+				legacy_pic->chip->unmask(0);
 			}
 			if (disable_timer_pin_1 > 0)
 				clear_IO_APIC_pin(0, pin1);
@@ -2972,14 +2969,14 @@
 		 */
 		replace_pin_at_irq_node(cfg, node, apic1, pin1, apic2, pin2);
 		setup_timer_IRQ0_pin(apic2, pin2, cfg->vector);
-		enable_8259A_irq(0);
+		legacy_pic->chip->unmask(0);
 		if (timer_irq_works()) {
 			apic_printk(APIC_QUIET, KERN_INFO "....... works.\n");
 			timer_through_8259 = 1;
 			if (nmi_watchdog == NMI_IO_APIC) {
-				disable_8259A_irq(0);
+				legacy_pic->chip->mask(0);
 				setup_nmi();
-				enable_8259A_irq(0);
+				legacy_pic->chip->unmask(0);
 			}
 			goto out;
 		}
@@ -2987,7 +2984,7 @@
 		 * Cleanup, just in case ...
 		 */
 		local_irq_disable();
-		disable_8259A_irq(0);
+		legacy_pic->chip->mask(0);
 		clear_IO_APIC_pin(apic2, pin2);
 		apic_printk(APIC_QUIET, KERN_INFO "....... failed.\n");
 	}
@@ -3006,22 +3003,22 @@
 
 	lapic_register_intr(0, desc);
 	apic_write(APIC_LVT0, APIC_DM_FIXED | cfg->vector);	/* Fixed mode */
-	enable_8259A_irq(0);
+	legacy_pic->chip->unmask(0);
 
 	if (timer_irq_works()) {
 		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");
 		goto out;
 	}
 	local_irq_disable();
-	disable_8259A_irq(0);
+	legacy_pic->chip->mask(0);
 	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | cfg->vector);
 	apic_printk(APIC_QUIET, KERN_INFO "..... failed.\n");
 
 	apic_printk(APIC_QUIET, KERN_INFO
 		    "...trying to set up timer as ExtINT IRQ...\n");
 
-	init_8259A(0);
-	make_8259A_irq(0);
+	legacy_pic->init(0);
+	legacy_pic->make_irq(0);
 	apic_write(APIC_LVT0, APIC_DM_EXTINT);
 
 	unlock_ExtINT_logic();
@@ -3063,7 +3060,7 @@
 	/*
 	 * calling enable_IO_APIC() is moved to setup_local_APIC for BP
 	 */
-	io_apic_irqs = nr_legacy_irqs ? ~PIC_IRQS : ~0UL;
+	io_apic_irqs = legacy_pic->nr_legacy_irqs ? ~PIC_IRQS : ~0UL;
 
 	apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n");
 	/*
@@ -3074,7 +3071,7 @@
 	sync_Arb_IDs();
 	setup_IO_APIC_irqs();
 	init_IO_APIC_traps();
-	if (nr_legacy_irqs)
+	if (legacy_pic->nr_legacy_irqs)
 		check_timer();
 }
 
@@ -3875,7 +3872,7 @@
 	/*
 	 * IRQs < 16 are already in the irq_2_pin[] map
 	 */
-	if (irq >= nr_legacy_irqs) {
+	if (irq >= legacy_pic->nr_legacy_irqs) {
 		cfg = desc->chip_data;
 		if (add_pin_to_irq_node_nopanic(cfg, node, ioapic, pin)) {
 			printk(KERN_INFO "can not add pin %d for irq %d\n",
diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c
index 0159a69..3817739 100644
--- a/arch/x86/kernel/apic/nmi.c
+++ b/arch/x86/kernel/apic/nmi.c
@@ -177,7 +177,7 @@
 error:
 	if (nmi_watchdog == NMI_IO_APIC) {
 		if (!timer_through_8259)
-			disable_8259A_irq(0);
+			legacy_pic->chip->mask(0);
 		on_each_cpu(__acpi_nmi_disable, NULL, 1);
 	}