| Message ID | 1427641227-7574-3-git-send-email-mst@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Sun, 03/29 17:04, Michael S. Tsirkin wrote: > commit d5dea7d95c48d7bc951cee4910a7fd9c0cd26fb0 > "PCI: msi: Disable msi interrupts when we initialize a pci device" > fixes kexec when the booting kernel does not enable msi interupts. > > Unfortunately the relevant functionality is in msi.c so it isn't > compiled in when CONFIG_PCI_MSI is off, which means such configurations > would still get interrupt storms. > > Fix by moving part of the functionality probe.c, and compiling it > unconditionally. Reviewed-by: Fam Zheng <famz@redhat.com> > > Cc: Eric W. Biederman <ebiederm@xmission.com> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/pci/msi.c | 12 ------------ > drivers/pci/probe.c | 16 ++++++++++++++++ > 2 files changed, 16 insertions(+), 12 deletions(-) > > diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > index 9942f68..f66be86 100644 > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -1041,18 +1041,6 @@ EXPORT_SYMBOL(pci_msi_enabled); > void pci_msi_init_pci_dev(struct pci_dev *dev) > { > INIT_LIST_HEAD(&dev->msi_list); > - > - /* Disable the msi hardware to avoid screaming interrupts > - * during boot. This is the power on reset default so > - * usually this should be a noop. > - */ > - dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); > - if (dev->msi_cap) > - pci_msi_set_enable(dev, 0); > - > - dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); > - if (dev->msix_cap) > - pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); > } > > /** > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 8d2f400..50dd934 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1483,10 +1483,26 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) > return dev; > } > > +static void pci_msi_setup_pci_dev(struct pci_dev *dev) > +{ > + /* Disable the msi hardware to avoid screaming interrupts > + * during boot. This is the power on reset default so > + * usually this should be a noop. > + */ > + dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); > + if (dev->msi_cap) > + pci_msi_set_enable(dev, 0); > + > + dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); > + if (dev->msix_cap) > + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); > +} > + > static void pci_init_capabilities(struct pci_dev *dev) > { > /* MSI/MSI-X list */ > pci_msi_init_pci_dev(dev); > + pci_msi_setup_pci_dev(dev); > > /* Buffers for saving PCIe and PCI-X capabilities */ > pci_allocate_cap_save_buffers(dev); > -- > MST > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Fam Zheng <famz@redhat.com> writes: > On Sun, 03/29 17:04, Michael S. Tsirkin wrote: >> commit d5dea7d95c48d7bc951cee4910a7fd9c0cd26fb0 >> "PCI: msi: Disable msi interrupts when we initialize a pci device" >> fixes kexec when the booting kernel does not enable msi interupts. >> >> Unfortunately the relevant functionality is in msi.c so it isn't >> compiled in when CONFIG_PCI_MSI is off, which means such configurations >> would still get interrupt storms. >> >> Fix by moving part of the functionality probe.c, and compiling it >> unconditionally. > > Reviewed-by: Fam Zheng <famz@redhat.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> I am a little surprised that there are systems that compile out MSI support, but I do remember the problem being a limitation of the code when wrote it and given how nasty screaming irqs are during boot up it seems well worth it to have a little extra code to turn them off. Eric >> Cc: Eric W. Biederman <ebiederm@xmission.com> >> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> >> --- >> drivers/pci/msi.c | 12 ------------ >> drivers/pci/probe.c | 16 ++++++++++++++++ >> 2 files changed, 16 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c >> index 9942f68..f66be86 100644 >> --- a/drivers/pci/msi.c >> +++ b/drivers/pci/msi.c >> @@ -1041,18 +1041,6 @@ EXPORT_SYMBOL(pci_msi_enabled); >> void pci_msi_init_pci_dev(struct pci_dev *dev) >> { >> INIT_LIST_HEAD(&dev->msi_list); >> - >> - /* Disable the msi hardware to avoid screaming interrupts >> - * during boot. This is the power on reset default so >> - * usually this should be a noop. >> - */ >> - dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); >> - if (dev->msi_cap) >> - pci_msi_set_enable(dev, 0); >> - >> - dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); >> - if (dev->msix_cap) >> - pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); >> } >> >> /** >> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c >> index 8d2f400..50dd934 100644 >> --- a/drivers/pci/probe.c >> +++ b/drivers/pci/probe.c >> @@ -1483,10 +1483,26 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) >> return dev; >> } >> >> +static void pci_msi_setup_pci_dev(struct pci_dev *dev) >> +{ >> + /* Disable the msi hardware to avoid screaming interrupts >> + * during boot. This is the power on reset default so >> + * usually this should be a noop. >> + */ >> + dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); >> + if (dev->msi_cap) >> + pci_msi_set_enable(dev, 0); >> + >> + dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); >> + if (dev->msix_cap) >> + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); >> +} >> + >> static void pci_init_capabilities(struct pci_dev *dev) >> { >> /* MSI/MSI-X list */ >> pci_msi_init_pci_dev(dev); >> + pci_msi_setup_pci_dev(dev); >> >> /* Buffers for saving PCIe and PCI-X capabilities */ >> pci_allocate_cap_save_buffers(dev); >> -- >> MST >> -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 9942f68..f66be86 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1041,18 +1041,6 @@ EXPORT_SYMBOL(pci_msi_enabled); void pci_msi_init_pci_dev(struct pci_dev *dev) { INIT_LIST_HEAD(&dev->msi_list); - - /* Disable the msi hardware to avoid screaming interrupts - * during boot. This is the power on reset default so - * usually this should be a noop. - */ - dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); - if (dev->msi_cap) - pci_msi_set_enable(dev, 0); - - dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); - if (dev->msix_cap) - pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); } /** diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 8d2f400..50dd934 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1483,10 +1483,26 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) return dev; } +static void pci_msi_setup_pci_dev(struct pci_dev *dev) +{ + /* Disable the msi hardware to avoid screaming interrupts + * during boot. This is the power on reset default so + * usually this should be a noop. + */ + dev->msi_cap = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (dev->msi_cap) + pci_msi_set_enable(dev, 0); + + dev->msix_cap = pci_find_capability(dev, PCI_CAP_ID_MSIX); + if (dev->msix_cap) + pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0); +} + static void pci_init_capabilities(struct pci_dev *dev) { /* MSI/MSI-X list */ pci_msi_init_pci_dev(dev); + pci_msi_setup_pci_dev(dev); /* Buffers for saving PCIe and PCI-X capabilities */ pci_allocate_cap_save_buffers(dev);
commit d5dea7d95c48d7bc951cee4910a7fd9c0cd26fb0 "PCI: msi: Disable msi interrupts when we initialize a pci device" fixes kexec when the booting kernel does not enable msi interupts. Unfortunately the relevant functionality is in msi.c so it isn't compiled in when CONFIG_PCI_MSI is off, which means such configurations would still get interrupt storms. Fix by moving part of the functionality probe.c, and compiling it unconditionally. Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/pci/msi.c | 12 ------------ drivers/pci/probe.c | 16 ++++++++++++++++ 2 files changed, 16 insertions(+), 12 deletions(-)