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authorJiang Liu <jiang.liu@linux.intel.com>2014-10-27 08:21:42 +0300
committerThomas Gleixner <tglx@linutronix.de>2014-12-16 16:08:15 +0300
commitcffe0a2b5a34c95a4dadc9ec7132690a5b0f6687 (patch)
tree136c802b57a9724e64510ae7531c7e366db479a8 /arch/x86/pci
parent67dc5e701fda884d49ed5c1904986bd5333610f4 (diff)
downloadlinux-cffe0a2b5a34c95a4dadc9ec7132690a5b0f6687.tar.xz
x86, irq: Keep balance of IOAPIC pin reference count
To keep balance of IOAPIC pin reference count, we need to protect pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable() from reentrance. There are two cases which will cause reentrance. The first case is caused by suspend/hibernation. If pcibios_disable_irq is called during suspending/hibernating, we don't release the assigned IRQ number, otherwise it may break the suspend/hibernation. So late when pcibios_enable_irq is called during resume, we shouldn't allocate IRQ number again. The second case is that function acpi_pci_irq_enable() may be called twice for PCI devices present at boot time as below: 1) pci_acpi_init() --> acpi_pci_irq_enable() if pci_routeirq is true 2) pci_enable_device() --> pcibios_enable_device() --> acpi_pci_irq_enable() We can't kill kernel parameter pci_routeirq yet because it's still needed for debugging purpose. So flag irq_managed is introduced to track whether IRQ number is assigned by OS and to protect pirq_enable_irq(), acpi_pci_irq_enable() and intel_mid_pci_irq_enable() from reentrance. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Len Brown <lenb@kernel.org> Link: http://lkml.kernel.org/r/1414387308-27148-13-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/pci')
-rw-r--r--arch/x86/pci/intel_mid_pci.c10
-rw-r--r--arch/x86/pci/irq.c7
2 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
index b9958c364075..44b9271580b5 100644
--- a/arch/x86/pci/intel_mid_pci.c
+++ b/arch/x86/pci/intel_mid_pci.c
@@ -210,6 +210,9 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev)
{
int polarity;
+ if (dev->irq_managed && dev->irq > 0)
+ return 0;
+
if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_TANGIER)
polarity = 0; /* active high */
else
@@ -224,13 +227,18 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev)
if (mp_map_gsi_to_irq(dev->irq, IOAPIC_MAP_ALLOC) < 0)
return -EBUSY;
+ dev->irq_managed = 1;
+
return 0;
}
static void intel_mid_pci_irq_disable(struct pci_dev *dev)
{
- if (!mp_should_keep_irq(&dev->dev) && dev->irq > 0)
+ if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed &&
+ dev->irq > 0) {
mp_unmap_irq(dev->irq);
+ dev->irq_managed = 0;
+ }
}
struct pci_ops intel_mid_pci_ops = {
diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index cb50e281d838..99884588a47a 100644
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -1202,6 +1202,9 @@ static int pirq_enable_irq(struct pci_dev *dev)
int irq;
struct io_apic_irq_attr irq_attr;
+ if (dev->irq_managed && dev->irq > 0)
+ return 0;
+
irq = IO_APIC_get_PCI_irq_vector(dev->bus->number,
PCI_SLOT(dev->devfn),
pin - 1, &irq_attr);
@@ -1228,6 +1231,7 @@ static int pirq_enable_irq(struct pci_dev *dev)
}
dev = temp_dev;
if (irq >= 0) {
+ dev->irq_managed = 1;
dev->irq = irq;
dev_info(&dev->dev, "PCI->APIC IRQ transform: "
"INT %c -> IRQ %d\n", 'A' + pin - 1, irq);
@@ -1269,8 +1273,9 @@ bool mp_should_keep_irq(struct device *dev)
static void pirq_disable_irq(struct pci_dev *dev)
{
if (io_apic_assign_pci_irqs && !mp_should_keep_irq(&dev->dev) &&
- dev->irq) {
+ dev->irq_managed && dev->irq) {
mp_unmap_irq(dev->irq);
dev->irq = 0;
+ dev->irq_managed = 0;
}
}