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| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2012-05-21 16:54:10 +0100 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-05-21 14:11:36 -0400 |
| commit | 68c2c39a76b094e9b2773e5846424ea674bf2c46 (patch) | |
| tree | b3959303806a6228adbbab234c474e16c81738ba | |
| parent | 201a52bea928687b7557728b176ac4f8a37d5cbd (diff) | |
| download | linux-68c2c39a76b094e9b2773e5846424ea674bf2c46.tar.gz linux-68c2c39a76b094e9b2773e5846424ea674bf2c46.tar.xz linux-68c2c39a76b094e9b2773e5846424ea674bf2c46.zip | |
xen: do not map the same GSI twice in PVHVM guests.
PV on HVM guests map GSIs into event channels. At restore time the
event channels are resumed by restore_pirqs.
Device drivers might try to register the same GSI again through ACPI at
restore time, but the GSI has already been mapped and bound by
restore_pirqs. This patch detects these situations and avoids
mapping the same GSI multiple times.
Without this patch we get:
(XEN) irq.c:2235: dom4: pirq 23 or emuirq 28 already mapped
and waste a pirq.
CC: stable@kernel.org
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| -rw-r--r-- | arch/x86/pci/xen.c | 4 | ||||
| -rw-r--r-- | drivers/xen/events.c | 5 | ||||
| -rw-r--r-- | include/xen/events.h | 3 |
3 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 7415aa927913..56ab74989cf1 100644 --- a/arch/x86/pci/xen.c +++ b/arch/x86/pci/xen.c @@ -64,6 +64,10 @@ static int xen_register_pirq(u32 gsi, int gsi_override, int triggering, int shareable = 0; char *name; + irq = xen_irq_from_gsi(gsi); + if (irq > 0) + return irq; + if (set_pirq) pirq = gsi; diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 4b33acd8ed4e..faae2f910ad2 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -611,7 +611,7 @@ static void disable_pirq(struct irq_data *data) disable_dynirq(data); } -static int find_irq_by_gsi(unsigned gsi) +int xen_irq_from_gsi(unsigned gsi) { struct irq_info *info; @@ -625,6 +625,7 @@ static int find_irq_by_gsi(unsigned gsi) return -1; } +EXPORT_SYMBOL_GPL(xen_irq_from_gsi); /* * Do not make any assumptions regarding the relationship between the @@ -644,7 +645,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi, mutex_lock(&irq_mapping_update_lock); - irq = find_irq_by_gsi(gsi); + irq = xen_irq_from_gsi(gsi); if (irq != -1) { printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n", irq, gsi); diff --git a/include/xen/events.h b/include/xen/events.h index 0f773708e02c..04399b28e821 100644 --- a/include/xen/events.h +++ b/include/xen/events.h @@ -103,6 +103,9 @@ int xen_irq_from_pirq(unsigned pirq); /* Return the pirq allocated to the irq. */ int xen_pirq_from_irq(unsigned irq); +/* Return the irq allocated to the gsi */ +int xen_irq_from_gsi(unsigned gsi); + /* Determine whether to ignore this IRQ if it is passed to a guest. */ int xen_test_irq_shared(int irq); |