diff options
| author |   Jan Kiszka <jan.kiszka@siemens.com> | 2021-08-30 10:08:10 +0200 |
|---|---|---|
| committer |   Bjorn Helgaas <bhelgaas@google.com> | 2021-09-20 15:09:14 -0500 |
| commit | 0e8ae5a6ff5952253cd7cc0260df838ab4c21009 (patch) | |
| tree | 551ddd9e818e7c5bfd652384603f25ef9637447f /drivers/pci/pcie/portdrv_core.c | |
| parent | Linux 5.15-rc2 (diff) | |
| download | linux-dev-0e8ae5a6ff5952253cd7cc0260df838ab4c21009.tar.xz linux-dev-0e8ae5a6ff5952253cd7cc0260df838ab4c21009.zip | |
PCI/portdrv: Do not setup up IRQs if there are no users
Avoid registering service IRQs if there is no service that offers them
or no driver to register a handler against them. This saves IRQ vectors
when they are limited (e.g. on x86) and also avoids that spurious events
could hit a missing handler. Such spurious events need to be generated
by the Jailhouse hypervisor for active MSI vectors when enabling or
disabling itself.
Link: https://lore.kernel.org/r/8f9a13ac-8ab1-15ac-06cb-c131b488a36f@siemens.com
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pcie/portdrv_core.c')
| -rw-r--r-- | drivers/pci/pcie/portdrv_core.c | 47 |
1 files changed, 30 insertions, 17 deletions
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index 3ee63968deaa..bf5440c3ca8a 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -166,9 +166,6 @@ static int pcie_init_service_irqs(struct pci_dev *dev, int *irqs, int mask) { int ret, i; - for (i = 0; i < PCIE_PORT_DEVICE_MAXSERVICES; i++) - irqs[i] = -1; - /* * If we support PME but can't use MSI/MSI-X for it, we have to * fall back to INTx or other interrupts, e.g., a system shared @@ -317,8 +314,10 @@ static int pcie_device_init(struct pci_dev *pdev, int service, int irq) */ int pcie_port_device_register(struct pci_dev *dev) { - int status, capabilities, i, nr_service; - int irqs[PCIE_PORT_DEVICE_MAXSERVICES]; + int status, capabilities, irq_services, i, nr_service; + int irqs[PCIE_PORT_DEVICE_MAXSERVICES] = { + [0 ... PCIE_PORT_DEVICE_MAXSERVICES-1] = -1 + }; /* Enable PCI Express port device */ status = pci_enable_device(dev); @@ -331,18 +330,32 @@ int pcie_port_device_register(struct pci_dev *dev) return 0; pci_set_master(dev); - /* - * Initialize service irqs. Don't use service devices that - * require interrupts if there is no way to generate them. - * However, some drivers may have a polling mode (e.g. pciehp_poll_mode) - * that can be used in the absence of irqs. Allow them to determine - * if that is to be used. - */ - status = pcie_init_service_irqs(dev, irqs, capabilities); - if (status) { - capabilities &= PCIE_PORT_SERVICE_HP; - if (!capabilities) - goto error_disable; + + irq_services = 0; + if (IS_ENABLED(CONFIG_PCIE_PME)) + irq_services |= PCIE_PORT_SERVICE_PME; + if (IS_ENABLED(CONFIG_PCIEAER)) + irq_services |= PCIE_PORT_SERVICE_AER; + if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) + irq_services |= PCIE_PORT_SERVICE_HP; + if (IS_ENABLED(CONFIG_PCIE_DPC)) + irq_services |= PCIE_PORT_SERVICE_DPC; + irq_services &= capabilities; + + if (irq_services) { + /* + * Initialize service IRQs. Don't use service devices that + * require interrupts if there is no way to generate them. + * However, some drivers may have a polling mode (e.g. + * pciehp_poll_mode) that can be used in the absence of IRQs. + * Allow them to determine if that is to be used. + */ + status = pcie_init_service_irqs(dev, irqs, irq_services); + if (status) { + irq_services &= PCIE_PORT_SERVICE_HP; + if (!irq_services) + goto error_disable; + } } /* Allocate child services if any */ |