nvmet: pci-epf: cleanup nvmet_pci_epf_raise_irq()

There is no point in taking the controller irq_lock and calling
nvmet_pci_epf_should_raise_irq() for a completion queue which does not
have IRQ enabled (NVMET_PCI_EPF_Q_IRQ_ENABLED flag is not set).
Move the test for the NVMET_PCI_EPF_Q_IRQ_ENABLED flag out of
nvmet_pci_epf_should_raise_irq() to the top of nvmet_pci_epf_raise_irq()
to return early when no IRQ should be raised.

Also, use dev_err_ratelimited() to avoid a message storm under load when
raising IRQs is failing.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Author: damien-lemoal

drivers/nvme/target/pci-epf.c

@@ -596,9 +596,6 @@ static bool nvmet_pci_epf_should_raise_irq(struct nvmet_pci_epf_ctrl *ctrl,
 	struct nvmet_pci_epf_irq_vector *iv = cq->iv;
 	bool ret;
 
-	if (!test_bit(NVMET_PCI_EPF_Q_IRQ_ENABLED, &cq->flags))
-		return false;
-
 	/* IRQ coalescing for the admin queue is not allowed. */
 	if (!cq->qid)
 		return true;
@@ -625,7 +622,8 @@ static void nvmet_pci_epf_raise_irq(struct nvmet_pci_epf_ctrl *ctrl,
 	struct pci_epf *epf = nvme_epf->epf;
 	int ret = 0;
 
-	if (!test_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags))
+	if (!test_bit(NVMET_PCI_EPF_Q_LIVE, &cq->flags) ||
+	    !test_bit(NVMET_PCI_EPF_Q_IRQ_ENABLED, &cq->flags))
 		return;
 
 	mutex_lock(&ctrl->irq_lock);
@@ -658,7 +656,9 @@ static void nvmet_pci_epf_raise_irq(struct nvmet_pci_epf_ctrl *ctrl,
 	}
 
 	if (ret)
-		dev_err(ctrl->dev, "Failed to raise IRQ (err=%d)\n", ret);
+		dev_err_ratelimited(ctrl->dev,
+				    "CQ[%u]: Failed to raise IRQ (err=%d)\n",
+				    cq->qid, ret);
 
 unlock:
 	mutex_unlock(&ctrl->irq_lock);