From: Marc Zyngier Date: Sun, 29 Nov 2020 13:52:08 +0000 (+0000) Subject: irqchip/gic-v3-its: Flag device allocation as proxied if behind a PCI bridge X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=34dd263fce3114147f21698f8e55e05b9e8185bd;p=linux.git irqchip/gic-v3-its: Flag device allocation as proxied if behind a PCI bridge An aliasing PCI bridge is another case where we should flag the corresponding allocation as "proxied", as MSIs are coming with the bridge's RID, and not the originating device's. Signed-off-by: Marc Zyngier Tested-by: John Garry Link: https://lore.kernel.org/r/20201129135208.680293-4-maz@kernel.org --- diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c index 87711e0f80140..ad2810c017ed1 100644 --- a/drivers/irqchip/irq-gic-v3-its-pci-msi.c +++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c @@ -67,11 +67,16 @@ static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev, /* * If pdev is downstream of any aliasing bridges, take an upper * bound of how many other vectors could map to the same DevID. + * Also tell the ITS that the signalling will come from a proxy + * device, and that special allocation rules apply. */ pci_for_each_dma_alias(pdev, its_get_pci_alias, &alias_dev); - if (alias_dev != pdev && alias_dev->subordinate) - pci_walk_bus(alias_dev->subordinate, its_pci_msi_vec_count, - &alias_count); + if (alias_dev != pdev) { + if (alias_dev->subordinate) + pci_walk_bus(alias_dev->subordinate, + its_pci_msi_vec_count, &alias_count); + info->flags |= MSI_ALLOC_FLAGS_PROXY_DEVICE; + } /* ITS specific DeviceID, as the core ITS ignores dev. */ info->scratchpad[0].ul = pci_msi_domain_get_msi_rid(domain, pdev);