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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-03-20 14:56:19 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-03-20 14:56:19 +0100
commit9e8ce4b96b781b003e3174fbbc62e1d4388c8b8f (patch)
tree3823451bc7aba0d2601ec67bdb9b43a3e51ea2f3
parent06e5801b8cb3fc057d88cb4dc03c0b64b2744cda (diff)
downloadlinux-sh-9e8ce4b96b781b003e3174fbbc62e1d4388c8b8f.tar.gz
Revert "x86/PCI: Refine the way to release PCI IRQ resources"
Commit b4b55cda5874 (Refine the way to release PCI IRQ resources) introduced a regression in the PCI IRQ resource management by causing the IRQ resource of a device, established when pci_enabled_device() is called on a fully disabled device, to be released when the driver is unbound from the device, regardless of the enable_cnt. This leads to the situation that an ill-behaved driver can now make a device unusable to subsequent drivers by an imbalance in their use of pci_enable/disable_device(). That is a serious problem for secondary drivers like vfio-pci, which are innocent of the transgressions of the previous driver. Since the solution of this problem is not immediate and requires further discussion, revert commit b4b55cda5874 and the issue it was supposed to address (a bug related to xen-pciback) will be taken care of in a different way going forward. Reported-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--arch/x86/include/asm/pci_x86.h2
-rw-r--r--arch/x86/pci/common.c34
-rw-r--r--arch/x86/pci/intel_mid_pci.c4
-rw-r--r--arch/x86/pci/irq.c15
-rw-r--r--drivers/acpi/pci_irq.c9
5 files changed, 32 insertions, 32 deletions
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index fa1195dae425..164e3f8d3c3d 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -93,6 +93,8 @@ 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 3d2612b68694..2fb384724ebb 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -513,31 +513,6 @@ 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) {
@@ -550,9 +525,6 @@ 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;
}
@@ -711,6 +683,12 @@ 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 efb849323c74..852aa4c92da0 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 (dev->irq_managed && 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;
- dev->irq = 0;
}
}
diff --git a/arch/x86/pci/irq.c b/arch/x86/pci/irq.c
index e71b3dbd87b8..5dc6ca5e1741 100644
--- a/arch/x86/pci/irq.c
+++ b/arch/x86/pci/irq.c
@@ -1256,9 +1256,22 @@ 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 && dev->irq_managed && dev->irq) {
+ if (io_apic_assign_pci_irqs && !mp_should_keep_irq(&dev->dev) &&
+ 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 e7f718d6918a..b1def411c0b8 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -485,6 +485,14 @@ void acpi_pci_irq_disable(struct pci_dev *dev)
if (!pin || !dev->irq_managed || dev->irq <= 0)
return;
+ /* Keep IOAPIC pin configuration when suspending */
+ if (dev->dev.power.is_prepared)
+ return;
+#ifdef CONFIG_PM
+ if (dev->dev.power.runtime_status == RPM_SUSPENDING)
+ return;
+#endif
+
entry = acpi_pci_irq_lookup(dev, pin);
if (!entry)
return;
@@ -505,6 +513,5 @@ void acpi_pci_irq_disable(struct pci_dev *dev)
if (gsi >= 0) {
acpi_unregister_gsi(gsi);
dev->irq_managed = 0;
- dev->irq = 0;
}
}