x86: Move pci init function to x86_init

The PCI initialization in pci_subsys_init() is a mess. pci_numaq_init,
pci_acpi_init, pci_visws_init and pci_legacy_init are called and each
implementation checks and eventually modifies the global variable
pcibios_scanned.

x86_init functions allow us to do this more elegant. The pci.init
function pointer is preset to pci_legacy_init. numaq, acpi and visws
can modify the pointer in their early setup functions. The functions
return 0 when they did the full initialization including bus scan. A
non zero return value indicates that pci_legacy_init needs to be
called either because the selected function failed or wants the
generic bus scan in pci_legacy_init to happen (e.g. visws).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80CFE@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/kernel/x86_init.c

@@ -7,6 +7,7 @@
 
 #include <asm/bios_ebda.h>
 #include <asm/paravirt.h>
+#include <asm/pci_x86.h>
 #include <asm/mpspec.h>
 #include <asm/setup.h>
 #include <asm/apic.h>
@@ -70,6 +71,10 @@ struct x86_init_ops x86_init __initdata = {
 	.iommu = {
 		.iommu_init		= iommu_init_noop,
 	},
+
+	.pci = {
+		.init			= x86_default_pci_init,
+	},
 };
 
 struct x86_cpuinit_ops x86_cpuinit __cpuinitdata = {