Commit 9c205304 authored by Keith Busch's avatar Keith Busch Committed by Bjorn Helgaas
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x86/PCI: VMD: Separate MSI and MSI-X vector sharing 



Child devices in a VMD domain that want to use MSI are slowing down MSI-X
using devices sharing the same vectors.  Move all MSI usage to a single VMD
vector, and MSI-X devices can share the rest.

Signed-off-by: default avatarKeith Busch <keith.busch@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarJon Derrick <jonathan.derrick@intel.com>
parent e382dffc

arch/x86/pci/vmd.c

+8 −4
Original line number Diff line number Diff line
@@ -169,11 +169,14 @@ static irq_hw_number_t vmd_get_hwirq(struct msi_domain_info *info, 
 * XXX: We can be even smarter selecting the best IRQ once we solve the

 * affinity problem.

 */

static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd)

static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *desc)

{

	int i, best = 0;

	int i, best = 1;

	unsigned long flags;



	if (!desc->msi_attrib.is_msix || vmd->msix_count == 1)

		return &vmd->irqs[0];



	raw_spin_lock_irqsave(&list_lock, flags);

	for (i = 1; i < vmd->msix_count; i++)

		if (vmd->irqs[i].count < vmd->irqs[best].count)
@@ -188,14 +191,15 @@ static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info, 
			unsigned int virq, irq_hw_number_t hwirq,

			msi_alloc_info_t *arg)

{

	struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(arg->desc)->bus);

	struct msi_desc *desc = arg->desc;

	struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus);

	struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL);



	if (!vmdirq)

		return -ENOMEM;



	INIT_LIST_HEAD(&vmdirq->node);

	vmdirq->irq = vmd_next_irq(vmd);

	vmdirq->irq = vmd_next_irq(vmd, desc);

	vmdirq->virq = virq;



	irq_domain_set_info(domain, virq, vmdirq->irq->vmd_vector, info->chip,

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