From: Jiang Liu <jiang.liu@linux.intel.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Bjorn Helgaas <bhelgaas@google.com>,
Randy Dunlap <rdunlap@infradead.org>,
Yinghai Lu <yinghai@kernel.org>, Borislav Petkov <bp@alien8.de>,
Grant Likely <grant.likely@linaro.org>,
x86@kernel.org, Len Brown <lenb@kernel.org>
Cc: Jiang Liu <jiang.liu@linux.intel.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
Tony Luck <tony.luck@intel.com>, Joerg Roedel <joro@8bytes.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
linux-acpi@vger.kernel.org
Subject: [Patch v4 09/16] x86, irq: Keep balance of IOAPIC pin reference count
Date: Thu, 28 Aug 2014 10:22:34 +0800 [thread overview]
Message-ID: <1409192561-19744-10-git-send-email-jiang.liu@linux.intel.com> (raw)
In-Reply-To: <1409192561-19744-1-git-send-email-jiang.liu@linux.intel.com>
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>
---
arch/x86/pci/intel_mid_pci.c | 9 ++++++++-
arch/x86/pci/irq.c | 7 ++++++-
drivers/acpi/pci_irq.c | 11 +++++++++--
include/linux/pci.h | 1 +
4 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c
index 3865116c51fb..6a855fef78fc 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 +227,17 @@ 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 (!dev->dev.power.is_prepared && dev->irq > 0)
+ if (!dev->dev.power.is_prepared && 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 bc1a2c341891..dd1369dbcc42 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 && !dev->dev.power.is_prepared &&
- dev->irq) {
+ dev->irq_managed && dev->irq > 0) {
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 c96887d5289e..4a89701dfe36 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 */
@@ -502,6 +506,9 @@ 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 61978a460841..3e0b92715512 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -347,6 +347,7 @@ 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 */
--
1.7.10.4
next prev parent reply other threads:[~2014-08-28 2:22 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-28 2:22 [Patch v4 00/16] Enable support of IOAPIC hotplug on x86 platforms Jiang Liu
2014-08-28 2:22 ` [Patch v4 01/16] x86, PCI, ACPI: Kill private function resource_to_addr() in arch/x86/pci/acpi.c Jiang Liu
2014-08-28 2:22 ` [Patch v4 02/16] ACPI: Correct return value of acpi_dev_resource_address_space() Jiang Liu
2014-08-28 2:22 ` [Patch v4 03/16] ACPI: Fix minor syntax issues in processor_core.c Jiang Liu
2014-08-28 2:22 ` [Patch v4 04/16] ACPI: Rename processor_core.c as apic_id.c Jiang Liu
2014-09-07 22:37 ` Rafael J. Wysocki
2014-09-08 12:51 ` Hanjun Guo
2014-09-08 21:00 ` Rafael J. Wysocki
2014-09-09 2:33 ` Jiang Liu
2014-08-28 2:22 ` [Patch v4 05/16] ACPI: Add interfaces to parse IOAPIC ID for IOAPIC hotplug Jiang Liu
2014-09-09 10:54 ` Thomas Gleixner
2014-09-10 1:58 ` Jiang Liu
2014-08-28 2:22 ` [Patch v4 06/16] x86, irq: Split out alloc_ioapic_save_registers() Jiang Liu
2014-08-28 2:22 ` [Patch v4 07/16] x86, irq: Prefer assigned ID in APIC ID register for x86_64 Jiang Liu
2014-09-09 11:04 ` Thomas Gleixner
2014-09-10 2:14 ` Jiang Liu
2014-08-28 2:22 ` [Patch v4 08/16] x86, irq: Remove __init marker for functions will be used by IOAPIC hotplug Jiang Liu
2014-08-28 2:22 ` Jiang Liu [this message]
2014-08-28 2:22 ` [Patch v4 10/16] x86, irq: Refine mp_register_ioapic() to prepare for " Jiang Liu
2014-08-28 2:22 ` [Patch v4 11/16] x86, irq, ACPI: Introduce a rwsem to protect IOAPIC operations from hotplug Jiang Liu
2014-08-28 2:22 ` [Patch v4 12/16] x86, irq, ACPI: Implement interface to support ACPI based IOAPIC hot-addition Jiang Liu
2014-09-09 12:20 ` Thomas Gleixner
2014-09-10 3:13 ` Jiang Liu
2014-09-10 20:06 ` Thomas Gleixner
2014-09-11 6:05 ` Jiang Liu
2014-09-11 6:08 ` Jiang Liu
2014-08-28 2:22 ` [Patch v4 13/16] x86, irq, ACPI: Implement interfaces to support ACPI based IOAPIC hot-removal Jiang Liu
2014-08-28 2:22 ` [Patch v4 14/16] x86, irq: Introduce helper to check whether an IOAPIC has been registered Jiang Liu
2014-09-09 12:37 ` Thomas Gleixner
2014-09-10 2:46 ` Jiang Liu
2014-09-10 20:08 ` Thomas Gleixner
2014-09-11 7:17 ` Jiang Liu
2014-08-28 2:22 ` [Patch v4 15/16] PCI: Remove PCI ioapic driver Jiang Liu
2014-08-28 2:22 ` [Patch v4 16/16] x86, irq, ACPI: Implement ACPI driver to support IOAPIC hotplug Jiang Liu
2014-09-07 22:05 ` [Patch v4 00/16] Enable support of IOAPIC hotplug on x86 platforms Rafael J. Wysocki
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