From: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx> This patch has been added to the 3.18 stable tree. If you have any objections, please let us know. =============== [ Upstream commit cffe0a2b5a34c95a4dadc9ec7132690a5b0f6687 ] 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@xxxxxxxxxxxxxxx> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Cc: Joerg Roedel <joro@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Yinghai Lu <yinghai@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Len Brown <lenb@xxxxxxxxxx> Link: http://lkml.kernel.org/r/1414387308-27148-13-git-send-email-jiang.liu@xxxxxxxxxxxxxxx Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx> --- arch/x86/pci/intel_mid_pci.c | 10 +++++++++- arch/x86/pci/irq.c | 7 ++++++- drivers/acpi/pci_irq.c | 11 +++++++++-- include/linux/pci.h | 1 + 4 files changed, 25 insertions(+), 4 deletions(-) diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c index b9958c3..44b9271 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 eb500c2..a47e2de 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); @@ -1257,8 +1261,9 @@ static int pirq_enable_irq(struct pci_dev *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; } } diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c index 6e6b80e..5f1fdca 100644 --- a/drivers/acpi/pci_irq.c +++ b/drivers/acpi/pci_irq.c @@ -413,6 +413,9 @@ int acpi_pci_irq_enable(struct pci_dev *dev) return 0; } + if (dev->irq_managed && dev->irq > 0) + return 0; + entry = acpi_pci_irq_lookup(dev, pin); if (!entry) { /* @@ -456,6 +459,7 @@ int acpi_pci_irq_enable(struct pci_dev *dev) return rc; } dev->irq = rc; + dev->irq_managed = 1; if (link) snprintf(link_desc, sizeof(link_desc), " -> Link[%s]", link); @@ -478,7 +482,7 @@ void acpi_pci_irq_disable(struct pci_dev *dev) u8 pin; pin = dev->pin; - if (!pin) + if (!pin || !dev->irq_managed || dev->irq <= 0) return; /* Keep IOAPIC pin configuration when suspending */ @@ -506,6 +510,9 @@ void acpi_pci_irq_disable(struct pci_dev *dev) */ dev_dbg(&dev->dev, "PCI INT %c disabled\n", pin_name(pin)); - if (gsi >= 0 && dev->irq > 0) + if (gsi >= 0) { acpi_unregister_gsi(gsi); + dev->irq = 0; + dev->irq_managed = 0; + } } diff --git a/include/linux/pci.h b/include/linux/pci.h index 7a34844..f188a66 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -355,6 +355,7 @@ struct pci_dev { unsigned int __aer_firmware_first:1; unsigned int broken_intx_masking:1; unsigned int io_window_1k:1; /* Intel P2P bridge 1K I/O windows */ + unsigned int irq_managed:1; pci_dev_flags_t dev_flags; atomic_t enable_cnt; /* pci_enable_device has been called */ -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html