diff options
author | Jiang Liu <jiang.liu@linux.intel.com> | 2015-02-05 13:44:47 +0800 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-02-05 15:09:26 +0100 |
commit | b4b55cda587442477a3a9f0669e26bba4b7800c0 (patch) | |
tree | e60388e241582d3d9a04e11e230a7805e9b5969b /arch | |
parent | 593669c2ac0fe18baee04a3cd5539a148aa48574 (diff) | |
download | op-kernel-dev-b4b55cda587442477a3a9f0669e26bba4b7800c0.zip op-kernel-dev-b4b55cda587442477a3a9f0669e26bba4b7800c0.tar.gz |
x86/PCI: Refine the way to release PCI IRQ resources
Some PCI device drivers assume that pci_dev->irq won't change after
calling pci_disable_device() and pci_enable_device() during suspend and
resume.
Commit c03b3b0738a5 ("x86, irq, mpparse: Release IOAPIC pin when
PCI device is disabled") frees PCI IRQ resources when pci_disable_device()
is called and reallocate IRQ resources when pci_enable_device() is
called again. This breaks above assumption. So commit 3eec595235c1
("x86, irq, PCI: Keep IRQ assignment for PCI devices during
suspend/hibernation") and 9eabc99a635a ("x86, irq, PCI: Keep IRQ
assignment for runtime power management") fix the issue by avoiding
freeing/reallocating IRQ resources during PCI device suspend/resume.
They achieve this by checking dev.power.is_prepared and
dev.power.runtime_status. PM maintainer, Rafael, then pointed out that
it's really an ugly fix which leaking PM internal state information to
IRQ subsystem.
Recently David Vrabel <david.vrabel@citrix.com> also reports an
regression in pciback driver caused by commit cffe0a2b5a34 ("x86, irq:
Keep balance of IOAPIC pin reference count"). Please refer to:
http://lkml.org/lkml/2015/1/14/546
So this patch refine the way to release PCI IRQ resources. Instead of
releasing PCI IRQ resources in pci_disable_device()/
pcibios_disable_device(), we now release it at driver unbinding
notification BUS_NOTIFY_UNBOUND_DRIVER. In other word, we only release
PCI IRQ resources when there's no driver bound to the PCI device, and
it keeps the assumption that pci_dev->irq won't through multiple
invocation of pci_enable_device()/pci_disable_device().
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/include/asm/pci_x86.h | 2 | ||||
-rw-r--r-- | arch/x86/pci/common.c | 34 | ||||
-rw-r--r-- | arch/x86/pci/intel_mid_pci.c | 4 | ||||
-rw-r--r-- | arch/x86/pci/irq.c | 15 |
4 files changed, 31 insertions, 24 deletions
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h index 164e3f8..fa1195d 100644 --- a/arch/x86/include/asm/pci_x86.h +++ b/arch/x86/include/asm/pci_x86.h @@ -93,8 +93,6 @@ extern raw_spinlock_t pci_config_lock; extern int (*pcibios_enable_irq)(struct pci_dev *dev); extern void (*pcibios_disable_irq)(struct pci_dev *dev); -extern bool mp_should_keep_irq(struct device *dev); - struct pci_raw_ops { int (*read)(unsigned int domain, unsigned int bus, unsigned int devfn, int reg, int len, u32 *val); diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c index 7b20bcc..ff1f0af 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -497,6 +497,31 @@ void __init pcibios_set_cache_line_size(void) } } +/* + * Some device drivers assume dev->irq won't change after calling + * pci_disable_device(). So delay releasing of IRQ resource to driver + * unbinding time. Otherwise it will break PM subsystem and drivers + * like xen-pciback etc. + */ +static int pci_irq_notifier(struct notifier_block *nb, unsigned long action, + void *data) +{ + struct pci_dev *dev = to_pci_dev(data); + + if (action != BUS_NOTIFY_UNBOUND_DRIVER) + return NOTIFY_DONE; + + if (pcibios_disable_irq) + pcibios_disable_irq(dev); + + return NOTIFY_OK; +} + +static struct notifier_block pci_irq_nb = { + .notifier_call = pci_irq_notifier, + .priority = INT_MIN, +}; + int __init pcibios_init(void) { if (!raw_pci_ops) { @@ -509,6 +534,9 @@ int __init pcibios_init(void) if (pci_bf_sort >= pci_force_bf) pci_sort_breadthfirst(); + + bus_register_notifier(&pci_bus_type, &pci_irq_nb); + return 0; } @@ -667,12 +695,6 @@ int pcibios_enable_device(struct pci_dev *dev, int mask) return 0; } -void pcibios_disable_device (struct pci_dev *dev) -{ - if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq) - pcibios_disable_irq(dev); -} - int pci_ext_cfg_avail(void) { if (raw_pci_ext_ops) diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c index 44b9271..95c2471 100644 --- a/arch/x86/pci/intel_mid_pci.c +++ b/arch/x86/pci/intel_mid_pci.c @@ -234,10 +234,10 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev) static void intel_mid_pci_irq_disable(struct pci_dev *dev) { - if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed && - dev->irq > 0) { + if (dev->irq_managed && dev->irq > 0) { mp_unmap_irq(dev->irq); dev->irq_managed = 0; + dev->irq = 0; } } diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c index 5dc6ca5..e71b3db 100644 --- a/arch/x86/pci/irq.c +++ b/arch/x86/pci/irq.c @@ -1256,22 +1256,9 @@ static int pirq_enable_irq(struct pci_dev *dev) return 0; } -bool mp_should_keep_irq(struct device *dev) -{ - if (dev->power.is_prepared) - return true; -#ifdef CONFIG_PM - if (dev->power.runtime_status == RPM_SUSPENDING) - return true; -#endif - - return false; -} - static void pirq_disable_irq(struct pci_dev *dev) { - if (io_apic_assign_pci_irqs && !mp_should_keep_irq(&dev->dev) && - dev->irq_managed && dev->irq) { + if (io_apic_assign_pci_irqs && dev->irq_managed && dev->irq) { mp_unmap_irq(dev->irq); dev->irq = 0; dev->irq_managed = 0; |