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authorMarc Zyngier <maz@kernel.org>2020-11-29 14:52:08 +0100
committerMarc Zyngier <maz@kernel.org>2020-12-11 15:47:50 +0100
commit34dd263fce3114147f21698f8e55e05b9e8185bd (patch)
tree6045eaf9f75dc183fa0a20e11e271ad985c53e1b
parentirqchip/gic-v3-its: Tag ITS device as shared if allocating for a proxy device (diff)
downloadlinux-34dd263fce3114147f21698f8e55e05b9e8185bd.tar.xz
linux-34dd263fce3114147f21698f8e55e05b9e8185bd.zip
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 <maz@kernel.org> Tested-by: John Garry <john.garry@huawei.com> Link: https://lore.kernel.org/r/20201129135208.680293-4-maz@kernel.org
-rw-r--r--drivers/irqchip/irq-gic-v3-its-pci-msi.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
index 87711e0f8014..ad2810c017ed 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);