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| author | Rui Wang <rui.y.wang@intel.com> | 2017-02-28 21:34:28 +0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-03-01 10:51:41 +0100 |
| commit | 153654dbe595a68845ba14d5b0bfe299fa6a7e99 (patch) | |
| tree | b7b8d2282f720f0815513173e381edfa0b8489a2 /arch/x86 | |
| parent | e86a2d2d34e20289ae7d46692e16d43c3a785db9 (diff) | |
| download | linux-153654dbe595a68845ba14d5b0bfe299fa6a7e99.tar.gz linux-153654dbe595a68845ba14d5b0bfe299fa6a7e99.tar.bz2 linux-153654dbe595a68845ba14d5b0bfe299fa6a7e99.zip | |
x86/PCI: Implement pcibios_release_device to release IRQ from IOAPIC
The revert of 991de2e59090 ("PCI, x86: Implement pcibios_alloc_irq()
and pcibios_free_irq()") causes a problem for IOAPIC hotplug. The
problem is that IRQs are allocated and freed in pci_enable_device()
and pci_disable_device(). But there are some drivers which don't call
pci_disable_device(), and they have good reasons not calling it, so
if they're using IOAPIC their IRQs won't have a chance to be released
from the IOAPIC. When this happens IOAPIC hot-removal fails with a
kernel stack dump and an error message like this:
[149335.697989] pin16 on IOAPIC2 is still in use.
It turns out that we can fix it in a different way without moving IRQ
allocation into pcibios_alloc_irq(), thus avoiding the regression of
991de2e59090. We can keep the allocation and freeing of IRQs as is
within pci_enable_device()/pci_disable_device(), without breaking any
previous assumption of the rest of the system, keeping compatibility
with both the legacy and the modern drivers. We can accomplish this by
implementing the existing __weak hook of pcibios_release_device() thus
when a pci device is about to be deleted we get notified in the hook
and take the chance to release its IRQ, if any, from the IOAPIC.
Implement pcibios_release_device() for x86 to release any IRQ not released
by the driver.
Signed-off-by: Rui Wang <rui.y.wang@intel.com>
Cc: tony.luck@intel.com
Cc: linux-pci@vger.kernel.org
Cc: rjw@rjwysocki.net
Cc: linux-acpi@vger.kernel.org
Cc: fengguang.wu@intel.com
Cc: helgaas@kernel.org
Cc: kbuild-all@01.org
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1488288869-31290-2-git-send-email-rui.y.wang@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/pci/common.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c index 0cb52ae0a8f0..190e718694b1 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -735,6 +735,15 @@ void pcibios_disable_device (struct pci_dev *dev) pcibios_disable_irq(dev); } +#ifdef CONFIG_ACPI_HOTPLUG_IOAPIC +void pcibios_release_device(struct pci_dev *dev) +{ + if (atomic_dec_return(&dev->enable_cnt) >= 0) + pcibios_disable_device(dev); + +} +#endif + int pci_ext_cfg_avail(void) { if (raw_pci_ext_ops) |