Currently pre-caculate each set vectors, and this way requires same
'max_vecs' and 'min_vecs' passed to pci_alloc_irq_vectors_affinity(),
then nvme_setup_irqs() has to retry in case of allocation failure.

This usage & interface is a bit awkward because the retry should have
been avoided by providing one reasonable 'min_vecs'.

Implement the callback of .calc_sets, so that pci_alloc_irq_vectors_affinity()
can calculate each set's vector after IRQ vectors is allocated and
before spread IRQ, then NVMe's retry in case of irq allocation failure
can be removed.

Reviewed-by: Keith Busch <keith.bu...@intel.com>
Signed-off-by: Ming Lei <ming....@redhat.com>
---
 drivers/nvme/host/pci.c | 62 +++++++++++++------------------------------------
 1 file changed, 16 insertions(+), 46 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 0086bdf80ea1..8c51252a897e 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2078,14 +2078,25 @@ static void nvme_calc_io_queues(struct nvme_dev *dev, 
unsigned int irq_queues)
        }
 }
 
+static void nvme_calc_irq_sets(struct irq_affinity *affd, int nvecs)
+{
+       struct nvme_dev *dev = affd->priv;
+
+       nvme_calc_io_queues(dev, nvecs);
+
+       affd->set_vectors[HCTX_TYPE_DEFAULT] = 
dev->io_queues[HCTX_TYPE_DEFAULT];
+       affd->set_vectors[HCTX_TYPE_READ] = dev->io_queues[HCTX_TYPE_READ];
+       affd->nr_sets = 2;
+}
+
 static int nvme_setup_irqs(struct nvme_dev *dev, unsigned int nr_io_queues)
 {
        struct pci_dev *pdev = to_pci_dev(dev->dev);
        struct irq_affinity affd = {
                .pre_vectors = 1,
-               .nr_sets = 2,
+               .calc_sets = nvme_calc_irq_sets,
+               .priv = dev,
        };
-       int *irq_sets = affd.set_vectors;
        int result = 0;
        unsigned int irq_queues, this_p_queues;
 
@@ -2102,50 +2113,8 @@ static int nvme_setup_irqs(struct nvme_dev *dev, 
unsigned int nr_io_queues)
        }
        dev->io_queues[HCTX_TYPE_POLL] = this_p_queues;
 
-       /*
-        * For irq sets, we have to ask for minvec == maxvec. This passes
-        * any reduction back to us, so we can adjust our queue counts and
-        * IRQ vector needs.
-        */
-       do {
-               nvme_calc_io_queues(dev, irq_queues);
-               irq_sets[0] = dev->io_queues[HCTX_TYPE_DEFAULT];
-               irq_sets[1] = dev->io_queues[HCTX_TYPE_READ];
-               if (!irq_sets[1])
-                       affd.nr_sets = 1;
-
-               /*
-                * If we got a failure and we're down to asking for just
-                * 1 + 1 queues, just ask for a single vector. We'll share
-                * that between the single IO queue and the admin queue.
-                * Otherwise, we assign one independent vector to admin queue.
-                */
-               if (irq_queues > 1)
-                       irq_queues = irq_sets[0] + irq_sets[1] + 1;
-
-               result = pci_alloc_irq_vectors_affinity(pdev, irq_queues,
-                               irq_queues,
-                               PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
-
-               /*
-                * Need to reduce our vec counts. If we get ENOSPC, the
-                * platform should support mulitple vecs, we just need
-                * to decrease our ask. If we get EINVAL, the platform
-                * likely does not. Back down to ask for just one vector.
-                */
-               if (result == -ENOSPC) {
-                       irq_queues--;
-                       if (!irq_queues)
-                               return result;
-                       continue;
-               } else if (result == -EINVAL) {
-                       irq_queues = 1;
-                       continue;
-               } else if (result <= 0)
-                       return -EIO;
-               break;
-       } while (1);
-
+       result = pci_alloc_irq_vectors_affinity(pdev, 1, irq_queues,
+                       PCI_IRQ_ALL_TYPES | PCI_IRQ_AFFINITY, &affd);
        return result;
 }
 
@@ -3021,6 +2990,7 @@ static struct pci_driver nvme_driver = {
 
 static int __init nvme_init(void)
 {
+       BUILD_BUG_ON(2 > IRQ_MAX_SETS);
        return pci_register_driver(&nvme_driver);
 }
 
-- 
2.9.5

Reply via email to