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Commit 3f2a230c authored by Ian Campbell's avatar Ian Campbell Committed by Konrad Rzeszutek Wilk
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xen: handled remapped IRQs when enabling a pcifront PCI device. 



This happens to not be an issue currently because we take pains to try
to ensure that the GSI-IRQ mapping is 1-1 in a PV guest and that
regular event channels do not clash. However a subsequent patch is
going to break this 1-1 mapping.

Signed-off-by: default avatarIan Campbell <ian.campbell@citrix.com>
Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
parent 100b33c8

arch/x86/pci/xen.c

+14 −8
Original line number Diff line number Diff line
@@ -226,21 +226,27 @@ static int xen_pcifront_enable_irq(struct pci_dev *dev) 
{

	int rc;

	int share = 1;

	u8 gsi;



	dev_info(&dev->dev, "Xen PCI enabling IRQ: %d\n", dev->irq);



	if (dev->irq < 0)

		return -EINVAL;

	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);

	if (rc < 0) {

		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",

			 rc);

		return rc;

	}



	if (dev->irq < NR_IRQS_LEGACY)

	if (gsi < NR_IRQS_LEGACY)

		share = 0;



	rc = xen_allocate_pirq(dev->irq, share, "pcifront");

	rc = xen_allocate_pirq(gsi, share, "pcifront");

	if (rc < 0) {

		dev_warn(&dev->dev, "Xen PCI IRQ: %d, failed to register:%d\n",

			 dev->irq, rc);

		dev_warn(&dev->dev, "Xen PCI: failed to register GSI%d: %d\n",

			 gsi, rc);

		return rc;

	}



	dev->irq = rc;

	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);

	return 0;

}