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[v4,2/2] powerpc/pseries: Pass MSI affinity to irq_create_mapping()

Message ID 20201126082852.1178497-3-lvivier@redhat.com (mailing list archive)
State Accepted
Commit 9ea69a55b3b9a71cded9726af591949c1138f235
Headers show
Series powerpc/pseries: fix MSI/X IRQ affinity on pseries | expand

Commit Message

Laurent Vivier Nov. 26, 2020, 8:28 a.m. UTC
With virtio multiqueue, normally each queue IRQ is mapped to a CPU.

Commit 0d9f0a52c8b9f ("virtio_scsi: use virtio IRQ affinity") exposed
an existing shortcoming of the arch code by moving virtio_scsi to
the automatic IRQ affinity assignment.

The affinity is correctly computed in msi_desc but this is not applied
to the system IRQs.

It appears the affinity is correctly passed to rtas_setup_msi_irqs() but
lost at this point and never passed to irq_domain_alloc_descs()
(see commit 06ee6d571f0e ("genirq: Add affinity hint to irq allocation"))
because irq_create_mapping() doesn't take an affinity parameter.

As the previous patch has added the affinity parameter to
irq_create_mapping() we can forward the affinity from rtas_setup_msi_irqs()
to irq_domain_alloc_descs().

With this change, the virtqueues are correctly dispatched between the CPUs
on pseries.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/platforms/pseries/msi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index 133f6adcb39c..b3ac2455faad 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -458,7 +458,8 @@  static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec_in, int type)
 			return hwirq;
 		}
 
-		virq = irq_create_mapping(NULL, hwirq);
+		virq = irq_create_mapping_affinity(NULL, hwirq,
+						   entry->affinity);
 
 		if (!virq) {
 			pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);