x86: Add pci_init_irq to x86_init

Moorestown wants to reuse pcibios_init_irq but needs to provide its
own implementation of pci_enable_irq. After we distangled the init we
can move the init_irq call to x86_init and remove the pci_enable_irq
!= NULL check in pcibios_init_irq. pci_enable_irq is compile time
initialized to pirq_enable_irq and the special cases which override it
(visws and acpi) set the x86_init function pointer to noop. That
allows MSRT to override pci_enable_irq and otherwise run
pcibios_init_irq unmodified.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80CFF@orsmsx508.amr.corp.intel.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/include/asm/pci_x86.h

@@ -110,7 +110,7 @@ extern void __init dmi_check_skip_isa_align(void);
 
 /* some common used subsys_initcalls */
 extern int __init pci_acpi_init(void);
-extern int __init pcibios_irq_init(void);
+extern void __init pcibios_irq_init(void);
 extern int __init pcibios_init(void);
 extern int pci_legacy_init(void);
 
@@ -187,6 +187,8 @@ static inline void mmio_config_writel(void __iomem *pos, u32 val)
 # else
 #  define x86_default_pci_init		pci_legacy_init
 # endif
+# define x86_default_pci_init_irq	pcibios_irq_init
 #else
 # define x86_default_pci_init		NULL
+# define x86_default_pci_init_irq	NULL
 #endif

arch/x86/include/asm/x86_init.h

@@ -101,9 +101,11 @@ struct x86_init_iommu {
  /*
   * struct x86_init_pci - platform specific pci init functions
  * @init:			platform specific pci init
+ * @init_irq:			platform specific pci irq init
  */
 struct x86_init_pci {
 	int (*init)(void);
+	void (*init_irq)(void);
 };
 
 /**

arch/x86/kernel/visws_quirks.c

@@ -238,6 +238,7 @@ void __init visws_early_detect(void)
 	x86_init.irqs.trap_init = visws_trap_init;
 	x86_init.timers.timer_init = visws_time_init;
 	x86_init.pci.init = pci_visws_init;
+	x86_init.pci.init_irq = x86_init_noop;
 
 	/*
 	 * Install reboot quirks:

arch/x86/kernel/x86_init.c

@@ -74,6 +74,7 @@ struct x86_init_ops x86_init __initdata = {
 
 	.pci = {
 		.init			= x86_default_pci_init,
+		.init_irq		= x86_default_pci_init_irq,
 	},
 };
 

arch/x86/pci/acpi.c

@@ -289,6 +289,7 @@ int __init pci_acpi_init(void)
 	acpi_irq_penalty_init();
 	pcibios_enable_irq = acpi_pci_irq_enable;
 	pcibios_disable_irq = acpi_pci_irq_disable;
+	x86_init.pci.init_irq = x86_init_noop;
 
 	if (pci_routeirq) {
 		/*

arch/x86/pci/irq.c

@@ -53,7 +53,7 @@ struct irq_router_handler {
 	int (*probe)(struct irq_router *r, struct pci_dev *router, u16 device);
 };
 
-int (*pcibios_enable_irq)(struct pci_dev *dev) = NULL;
+int (*pcibios_enable_irq)(struct pci_dev *dev) = pirq_enable_irq;
 void (*pcibios_disable_irq)(struct pci_dev *dev) = NULL;
 
 /*
@@ -1110,12 +1110,12 @@ static struct dmi_system_id __initdata pciirq_dmi_table[] = {
 	{ }
 };
 
-int __init pcibios_irq_init(void)
+void __init pcibios_irq_init(void)
 {
 	DBG(KERN_DEBUG "PCI: IRQ init\n");
 
-	if (pcibios_enable_irq || raw_pci_ops == NULL)
-		return 0;
+	if (raw_pci_ops == NULL)
+		return;
 
 	dmi_check_system(pciirq_dmi_table);
 
@@ -1142,8 +1142,6 @@ int __init pcibios_irq_init(void)
 			pirq_table = NULL;
 	}
 
-	pcibios_enable_irq = pirq_enable_irq;
-
 	pcibios_fixup_irqs();
 
 	if (io_apic_assign_pci_irqs && pci_routeirq) {
@@ -1157,8 +1155,6 @@ int __init pcibios_irq_init(void)
 		for_each_pci_dev(dev)
 			pirq_enable_irq(dev);
 	}
-
-	return 0;
 }
 
 static void pirq_penalize_isa_irq(int irq, int active)

arch/x86/pci/legacy.c

@@ -60,7 +60,7 @@ int __init pci_subsys_init(void)
 		pci_legacy_init();
 
 	pcibios_fixup_peer_bridges();
-	pcibios_irq_init();
+	x86_init.pci.init_irq();
 	pcibios_init();
 
 	return 0;