[PATCH 3/5] Introduce pci=ioapicreroute kernel cmdline option

From: Stefan Assmann
Date: Wed Jun 11 2008 - 11:07:11 EST


From: Stefan Assmann <sassmann@xxxxxxx>

Introduce pci=ioapicreroute kernel cmdline option to enable rerouting of boot
interrupts to the primary io-apic.

Signed-off-by: Stefan Assmann <sassmann@xxxxxxx>
Signed-off-by: Olaf Dabrunz <od@xxxxxxx>
---
Documentation/kernel-parameters.txt | 4 ++++
arch/x86/pci/common.c | 5 +++++
include/asm-x86/io_apic.h | 4 ++++
include/asm-x86/pci.h | 1 +
4 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4bfd0e6..01b638b 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1510,6 +1510,10 @@ and is between 256 and 4096 characters. It is defined in the file
noioapicquirk [APIC] Disable all boot interrupt quirks.
Safety option to keep boot IRQs enabled. This
should never be necessary.
+ ioapicreroute [APIC] Enable rerouting of boot IRQs to the
+ primary IO-APIC for bridges that cannot disable
+ boot IRQs. This fixes a source of spurious IRQs
+ when the system masks IRQs.
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
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 4ddb5cb..00a319c 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -23,6 +23,7 @@ unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
static int pci_bf_sort;
int pci_routeirq;
int noioapicquirk;
+int noioapicreroute = 1;
int pcibios_last_bus = -1;
unsigned long pirq_table_addr;
struct pci_bus *pci_root_bus;
@@ -499,6 +500,10 @@ char * __devinit pcibios_setup(char *str)
} else if (!strcmp(str, "noioapicquirk")) {
noioapicquirk = 1;
return NULL;
+ } else if (!strcmp(str, "ioapicreroute")) {
+ if (noioapicreroute != -1)
+ noioapicreroute = 0;
+ return NULL;
}
return str;
}
diff --git a/include/asm-x86/io_apic.h b/include/asm-x86/io_apic.h
index 92c2916..4ea118a 100644
--- a/include/asm-x86/io_apic.h
+++ b/include/asm-x86/io_apic.h
@@ -160,12 +160,16 @@ extern int skip_ioapic_setup;
/* 1 if "noapic" boot option passed */
extern int noioapicquirk;

+/* -1 if "noapic" boot option passed */
+extern int noioapicreroute;
+
/* 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;
+ noioapicreroute = -1;
skip_ioapic_setup = 1;
}

diff --git a/include/asm-x86/pci.h b/include/asm-x86/pci.h
index 30eec93..52a29f7 100644
--- a/include/asm-x86/pci.h
+++ b/include/asm-x86/pci.h
@@ -20,6 +20,7 @@ struct pci_sysdata {

extern int pci_routeirq;
extern int noioapicquirk;
+extern int ioapicreroute;

/* 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,
--
1.5.2.4

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