[PATCH 4/5] nvme-pci: simplify nvme_setup_irqs() via .setup_affinity callback

Ming Lei
2019-01-25T09:54:44Z

Use the callback of .setup_affinity() to re-caculate number
of queues, and build irqs affinity with help of irq_build_affinity().

Then nvme_setup_irqs() gets simplified a lot.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/nvme/host/pci.c | 97 ++++++++++++++++++++++++-------------------------
1 file changed, 48 insertions(+), 49 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 9bc585415d9b..24496de0a29b 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2078,17 +2078,58 @@ static void nvme_calc_io_queues(struct nvme_dev *dev, unsigned int irq_queues)
}
}

+static int nvme_setup_affinity(const struct irq_affinity *affd,
+ struct irq_affinity_desc *masks,
+ unsigned int nmasks)
+{
+ struct nvme_dev *dev = affd->priv;
+ int affvecs = nmasks - affd->pre_vectors - affd->post_vectors;
+ int curvec, usedvecs;
+ int i;
+
+ nvme_calc_io_queues(dev, nmasks);
+
+ /* Fill out vectors at the beginning that don't need affinity */
+ for (curvec = 0; curvec < affd->pre_vectors; curvec++)
+ cpumask_copy(&masks[curvec].mask, cpu_possible_mask);
+
+ for (i = 0, usedvecs = 0; i < HCTX_TYPE_POLL; i++) {
+ int this_vecs = dev->io_queues[i];
+ int ret;
+
+ if (!this_vecs)
+ break;
+
+ ret = irq_build_affinity(affd, curvec, this_vecs, curvec,
+ masks, nmasks);
+ if (ret)
+ return ret;
+
+ curvec += this_vecs;
+ usedvecs += this_vecs;
+ }
+
+ /* Fill out vectors at the end that don't need affinity */
+ curvec = affd->pre_vectors + min(usedvecs, affvecs);
+ for (; curvec < nmasks; curvec++)
+ cpumask_copy(&masks[curvec].mask, cpu_possible_mask);
+
+ /* Mark the managed interrupts */
+ for (i = affd->pre_vectors; i < nmasks - affd->post_vectors; i++)
+ masks[i].is_managed = 1;
+
+ return 0;
+}
+
static int nvme_setup_irqs(struct nvme_dev *dev, unsigned int nr_io_queues)
{
struct pci_dev *pdev = to_pci_dev(dev->dev);
- int irq_sets[2];
struct irq_affinity affd = {
.pre_vectors = 1,
- .nr_sets = ARRAY_SIZE(irq_sets),
- .sets = irq_sets,
+ .setup_affinity = nvme_setup_affinity,
+ .priv = dev,
};
- int result = 0;
- unsigned int irq_queues, this_p_queues;
+ int result, irq_queues, this_p_queues;

/*
* Poll queues don't need interrupts, but we need at least one IO
@@ -2103,50 +2144,8 @@ 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;
}

--
2.9.5