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From: Jiang Liu <jiang.liu@linux.intel.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Thomas Gleixner <tglx@linutronix.de>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Yinghai Lu <yinghai@kernel.org>, Borislav Petkov <bp@alien8.de>,
	Lv Zheng <lv.zheng@intel.com>, Ingo Molnar <mingo@redhat.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, Len Brown <lenb@kernel.org>
Cc: Jiang Liu <jiang.liu@linux.intel.com>,
	Tony Luck <tony.luck@intel.com>,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	linux-acpi@vger.kernel.org
Subject: [Patch v2 20/22] x86/PCI: Refine the way to release PCI IRQ resources
Date: Wed, 28 Jan 2015 18:57:38 +0800	[thread overview]
Message-ID: <1422442660-455-21-git-send-email-jiang.liu@linux.intel.com> (raw)
In-Reply-To: <1422442660-455-1-git-send-email-jiang.liu@linux.intel.com>

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 c03b3b0738a56cf283b0d05256988d5e3c8bd719 ("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>
---
 arch/x86/include/asm/pci_x86.h |    2 --
 arch/x86/pci/common.c          |   30 ++++++++++++++++++++++++++++--
 arch/x86/pci/intel_mid_pci.c   |    4 ++--
 arch/x86/pci/irq.c             |   15 +--------------
 drivers/acpi/pci_irq.c         |    9 +--------
 5 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index 164e3f8d3c3d..fa1195dae425 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 7b20bccf3648..99f15ed19f38 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -497,6 +497,25 @@ void __init pcibios_set_cache_line_size(void)
 	}
 }
 
+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 +528,9 @@ 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;
 }
 
@@ -669,8 +691,12 @@ int pcibios_enable_device(struct pci_dev *dev, int mask)
 
 void pcibios_disable_device (struct pci_dev *dev)
 {
-	if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq)
-		pcibios_disable_irq(dev);
+	/*
+	 * 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.
+	 */
 }
 
 int pci_ext_cfg_avail(void)
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
index 44b9271580b5..95c2471f6819 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 5dc6ca5e1741..e71b3dbd87b8 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;
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index b1def411c0b8..e7f718d6918a 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -485,14 +485,6 @@ 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;
@@ -513,5 +505,6 @@ void acpi_pci_irq_disable(struct pci_dev *dev)
 	if (gsi >= 0) {
 		acpi_unregister_gsi(gsi);
 		dev->irq_managed = 0;
+		dev->irq = 0;
 	}
 }
-- 
1.7.10.4


  parent reply	other threads:[~2015-01-28 20:23 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-28 10:57 [Patch v2 00/22] Improve ACPI resource parsing interfaces and enable IOAPIC hotplug Jiang Liu
2015-01-28 10:57 ` [Patch v2 01/22] ACPICA: Resources: Provide common part for struct acpi_resource_address structures Jiang Liu
2015-01-28 10:57 ` [Patch v2 02/22] ACPI: Remove redundant check in function acpi_dev_resource_address_space() Jiang Liu
2015-01-28 10:57 ` [Patch v2 03/22] ACPI: Implement proper length checks for mem resources Jiang Liu
2015-01-28 10:57 ` [Patch v2 04/22] ACPI: Use the length check for io resources as well Jiang Liu
2015-01-28 10:57 ` [Patch v2 05/22] ACPI: Let the parser return false for disabled resources Jiang Liu
2015-01-28 10:57 ` [Patch v2 06/22] ACPI: Unify the parsing of address_space and ext_address_space Jiang Liu
2015-01-28 10:57 ` [Patch v2 07/22] ACPI: Move the window flag logic to the combined parser Jiang Liu
2015-01-28 10:57 ` [Patch v2 08/22] ACPI: Add prefetch decoding to the address space parser Jiang Liu
2015-01-28 10:57 ` [Patch v2 09/22] ACPI: Fix a bug in parsing ACPI Memroy24 resource Jiang Liu
2015-01-28 23:15   ` Bjorn Helgaas
2015-01-28 10:57 ` [Patch v2 10/22] ACPI: Normalize return value of resource parser functions Jiang Liu
2015-01-28 10:57 ` [Patch v2 11/22] ACPI: Set flag IORESOURCE_UNSET for unassigned resources Jiang Liu
2015-01-28 10:57 ` [Patch v2 12/22] ACPI: Enforce stricter checks for address space descriptors Jiang Liu
2015-01-28 10:57 ` [Patch v2 13/22] ACPI: Return translation offset when parsing ACPI address space resources Jiang Liu
2015-01-28 10:57 ` [Patch v2 14/22] ACPI: Translate resource into master side address for bridge window resources Jiang Liu
2015-01-28 10:57 ` [Patch v2 15/22] ACPI: Add field offset to struct resource_list_entry Jiang Liu
2015-01-28 10:57 ` [Patch v2 16/22] ACPI: Introduce helper function acpi_dev_filter_resource_type() Jiang Liu
2015-01-28 10:57 ` [Patch v2 17/22] resources: Move struct resource_list_entry from ACPI into resource core Jiang Liu
2015-02-05  1:56   ` Vinod Koul
2015-01-28 10:57 ` [Patch v2 18/22] PCI: Use common resource list management code instead of private implementation Jiang Liu
2015-01-28 13:46   ` Will Deacon
2015-01-28 23:34   ` Bjorn Helgaas
2015-01-28 10:57 ` [Patch v2 19/22] x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation Jiang Liu
2015-01-28 23:37   ` Bjorn Helgaas
2015-01-29  3:00     ` Jiang Liu
2015-01-28 23:51   ` Bjorn Helgaas
2015-01-29  3:11     ` Jiang Liu
2015-01-28 10:57 ` Jiang Liu [this message]
2015-01-28 23:38   ` [Patch v2 20/22] x86/PCI: Refine the way to release PCI IRQ resources Bjorn Helgaas
2015-01-28 10:57 ` [Patch v2 21/22] ACPI: Add interfaces to parse IOAPIC ID for IOAPIC hotplug Jiang Liu
2015-01-28 10:57 ` [Patch v2 22/22] x86/irq, ACPI: Implement ACPI driver to support " Jiang Liu

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