x86, pci: introduce pci=noioapicquirk kernel cmdline option

Introduce pci=noioapicquirk kernel cmdline option to disable all boot
interrupt quirks
Signed-off-by: Stefan Assmann <sassmann@suse.de>
Signed-off-by: Olaf Dabrunz <od@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Documentation/kernel-parameters.txt

@@ -1518,6 +1518,9 @@ and is between 256 and 4096 characters. It is defined in the file
 		nomsi		[MSI] If the PCI_MSI kernel config parameter is
 				enabled, this kernel boot option can be used to
 				disable the use of MSI interrupts system-wide.
+		noioapicquirk	[APIC] Disable all boot interrupt quirks.
+				Safety option to keep boot IRQs enabled. This
+				should never be necessary.
 		biosirq		[X86-32] Use PCI BIOS calls to get the interrupt
 				routing table. These calls are known to be buggy
 				on several machines and they hang the machine

arch/x86/pci/common.c

@@ -22,6 +22,7 @@ unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
 
 static int pci_bf_sort;
 int pci_routeirq;
+int noioapicquirk;
 int pcibios_last_bus = -1;
 unsigned long pirq_table_addr;
 struct pci_bus *pci_root_bus;
@@ -495,6 +496,9 @@ char * __devinit  pcibios_setup(char *str)
 	} else if (!strcmp(str, "skip_isa_align")) {
 		pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
 		return NULL;
+	} else if (!strcmp(str, "noioapicquirk")) {
+		noioapicquirk = 1;
+		return NULL;
 	}
 	return str;
 }

include/asm-x86/io_apic.h

@@ -157,11 +157,15 @@ extern int sis_apic_bug;
 /* 1 if "noapic" boot option passed */
 extern int skip_ioapic_setup;
 
+/* 1 if "noapic" boot option passed */
+extern int noioapicquirk;
+
 /* 1 if the timer IRQ uses the '8259A Virtual Wire' mode */
 extern int timer_through_8259;
 
 static inline void disable_ioapic_setup(void)
 {
+	noioapicquirk = 1;
 	skip_ioapic_setup = 1;
 }
 

include/asm-x86/pci.h

@@ -19,6 +19,7 @@ struct pci_sysdata {
 };
 
 extern int pci_routeirq;
+extern int noioapicquirk;
 
 /* scan a bus after allocating a pci_sysdata for it */
 extern struct pci_bus *pci_scan_bus_on_node(int busno, struct pci_ops *ops,