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authorMarc Zyngier <marc.zyngier@arm.com>2015-10-02 14:43:06 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2015-10-16 13:07:16 +0100
commit54fa97eeb9e22b47d68b67ee00987afa7fbc2178 (patch)
treebf5cbab9a60df9291dcc92592f21a1c52cc593ee /drivers/pci
parent098259eb16675a83e1d6ea31e06dc3ec152810a2 (diff)
downloadlinux-54fa97eeb9e22b47d68b67ee00987afa7fbc2178.tar.bz2
PCI/MSI: Allow the MSI domain to be device-specific
So far, we've always considered that for a given PCI device, its MSI controller was either set by the architecture-specific pcibios hook, or simply inherited from the host bridge. This doesn't cover things like firmware-defined topologies like msi-map (DT) or IORT (ACPI), which can provide information about which MSI controller to use on a per-device basis. This patch adds the necessary hook into the MSI code to allow this feature, and provides the msi-map functionnality as a first implementation. Acked-by: Rob Herring <robh@kernel.org> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/msi.c17
-rw-r--r--drivers/pci/probe.c8
2 files changed, 25 insertions, 0 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 5ab5c4f8dcb0..4cd6f3abcecf 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1359,4 +1359,21 @@ u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
return rid;
}
+
+/**
+ * pci_msi_get_device_domain - Get the MSI domain for a given PCI device
+ * @pdev: The PCI device
+ *
+ * Use the firmware data to find a device-specific MSI domain
+ * (i.e. not one that is ste as a default).
+ *
+ * Returns: The coresponding MSI domain or NULL if none has been found.
+ */
+struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
+{
+ u32 rid = 0;
+
+ pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
+ return of_msi_map_get_device_domain(&pdev->dev, rid);
+}
#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 7c333f8c2327..f14a970b61fa 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1639,6 +1639,14 @@ static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev)
if (d)
return d;
+ /*
+ * Let's see if we have a firmware interface able to provide
+ * the domain.
+ */
+ d = pci_msi_get_device_domain(dev);
+ if (d)
+ return d;
+
return NULL;
}