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Groups > linux.kernel > #1240740

[PATCH v2 7/8] PCI: Add per-device MSI domain hook

From Marc Zyngier <marc.zyngier@arm.com>
Newsgroups linux.kernel
Subject [PATCH v2 7/8] PCI: Add per-device MSI domain hook
Date 2015-10-06 19:10 +0200
Message-ID <qgDUv-3Yw-23@gated-at.bofh.it> (permalink)
References <qgDUu-3Yw-9@gated-at.bofh.it>
Organization linux.* mail to news gateway

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So far, we have considered that the MSI domain for a device was
either set via the architecture-dependent pcibios implementation
or inherited from the host bridge.

As we're about to break that assumption, add pci_dev_msi_domain
which is the equivalent of pci_host_bridge_msi_domain, but for
a single device.

Other than moving things around a bit, this patch on its own
has no effect.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/pci/probe.c | 35 ++++++++++++++++++++++++++++++-----
 1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 8361d27..7c333f8 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1622,15 +1622,40 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_enable_acs(dev);
 }
 
+/*
+ * This is the equivalent of pci_host_bridge_msi_domain that acts on
+ * devices. Firmware interfaces that can select the MSI domain on a
+ * per-device basis should be called from here.
+ */
+static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev)
+{
+	struct irq_domain *d;
+
+	/*
+	 * If a domain has been set through the pcibios_add_device
+	 * callback, then this is the one (platform code knows best).
+	 */
+	d = dev_get_msi_domain(&dev->dev);
+	if (d)
+		return d;
+
+	return NULL;
+}
+
 static void pci_set_msi_domain(struct pci_dev *dev)
 {
+	struct irq_domain *d;
+
 	/*
-	 * If no domain has been set through the pcibios_add_device
-	 * callback, inherit the default from the bus device.
+	 * If the platform or firmware interfaces cannot supply a
+	 * device-specific MSI domain, then inherit the default domain
+	 * from the host bridge itself.
 	 */
-	if (!dev_get_msi_domain(&dev->dev))
-		dev_set_msi_domain(&dev->dev,
-				   dev_get_msi_domain(&dev->bus->dev));
+	d = pci_dev_msi_domain(dev);
+	if (!d)
+		d = dev_get_msi_domain(&dev->bus->dev);
+
+	dev_set_msi_domain(&dev->dev, d);
 }
 
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
-- 
2.1.4

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Thread

[PATCH v2 7/8] PCI: Add per-device MSI domain hook Marc Zyngier <marc.zyngier@arm.com> - 2015-10-06 19:10 +0200
  Re: [PATCH v2 7/8] PCI: Add per-device MSI domain hook Bjorn Helgaas <helgaas@kernel.org> - 2015-10-15 22:20 +0200

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