From ae6dc7deac2a8639595437af3df5fade878a1601 Mon Sep 17 00:00:00 2001 From: Gabriele Paoloni Date: Tue, 23 May 2017 15:23:59 +0100 Subject: [PATCH] PCI/portdrv: Allocate MSI/MSI-X vector for Downstream Port Containment Currently pcie_port_enable_irq_vec() only allocates MSI/MSI-X vectors for PME, hotplug, and AER. The Downstream Port Containment feature also supports MSI/MSI-X interrupts, so allocate a vector for it, too. Signed-off-by: Liudongdong Signed-off-by: Gabriele Paoloni [bhelgaas: changelog, comment] Signed-off-by: Bjorn Helgaas Reviewed-by: Christoph Hellwig --- drivers/pci/pcie/portdrv_core.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c index e00b5da07fef..313a21df1692 100644 --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -123,6 +123,33 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask) nvec = max(nvec, entry + 1); } + if (mask & PCIE_PORT_SERVICE_DPC) { + u16 reg16, pos; + + /* + * Per PCIe r4.0 (v0.9), sec 7.9.15.2, the DPC Interrupt + * Message Number in the DPC Capability register indicates + * which MSI/MSI-X vector is used for DPC. + * + * "For MSI, the [DPC Interrupt Message Number] indicates + * the offset between the base Message Data and the + * interrupt message that is generated." + * + * "For MSI-X, the [DPC Interrupt Message Number] indicates + * which MSI-X Table entry is used to generate the + * interrupt message." + */ + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC); + pci_read_config_word(dev, pos + PCI_EXP_DPC_CAP, ®16); + entry = reg16 & 0x1f; + if (entry >= nr_entries) + goto out_free_irqs; + + irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, entry); + + nvec = max(nvec, entry + 1); + } + /* * If nvec is equal to the allocated number of entries, we can just use * what we have. Otherwise, the port has some extra entries not for the -- 2.20.1