RE: [PATCH v2 net-next 4/5] stmmac: intel: add support for multi-vector msi and msi-x

[Ong, Boon Leong]

>+static int stmmac_config_multi_msi(struct pci_dev *pdev,
>+				   struct plat_stmmacenet_data *plat,
>+				   struct stmmac_resources *res)
>+{
For optimum RX & TX queue processing on the same IRQ, we should use
irq_set_affinity_hint() to set those RXQ and TXQ IRQ to the same CPU.
This will benefit processing for up-coming XDP TX and XDP TX ZC processing.

cpumask_t cpu_mask;

>+	int ret;
>+	int i;
>+
>+	if (plat->msi_rx_base_vec >= STMMAC_MSI_VEC_MAX ||
>+	    plat->msi_tx_base_vec >= STMMAC_MSI_VEC_MAX) {
>+		dev_info(&pdev->dev, "%s: Invalid RX & TX vector defined\n",
>+			 __func__);
>+		return -1;
>+	}
>+
>+	ret = pci_alloc_irq_vectors(pdev, 2, STMMAC_MSI_VEC_MAX,
>+				    PCI_IRQ_MSI | PCI_IRQ_MSIX);
>+	if (ret < 0) {
>+		dev_info(&pdev->dev, "%s: multi MSI enablement failed\n",
>+			 __func__);
>+		return ret;
>+	}
>+
>+	/* For RX MSI */
>+	for (i = 0; i < plat->rx_queues_to_use; i++) {
>+		res->rx_irq[i] = pci_irq_vector(pdev,
>+						plat->msi_rx_base_vec + i * 2);

		cpumask_clear(&cpu_mask);
		cpumask_set_cpu(i % num_online_cpus(), &cpu_mask);
		irq_set_affinity_hint(res->rx_irq[i], &cpu_mask);

>+	}
>+
>+	/* For TX MSI */
>+	for (i = 0; i < plat->tx_queues_to_use; i++) {
>+		res->tx_irq[i] = pci_irq_vector(pdev,
>+						plat->msi_tx_base_vec + i * 2);

		cpumask_clear(&cpu_mask);
		cpumask_set_cpu(i % num_online_cpus(), &cpu_mask);
		irq_set_affinity_hint(res->tx_irq[i], &cpu_mask);

>+	}
>+
>+	if (plat->msi_mac_vec < STMMAC_MSI_VEC_MAX)
>+		res->irq = pci_irq_vector(pdev, plat->msi_mac_vec);
>+	if (plat->msi_wol_vec < STMMAC_MSI_VEC_MAX)
>+		res->wol_irq = pci_irq_vector(pdev, plat->msi_wol_vec);
>+	if (plat->msi_lpi_vec < STMMAC_MSI_VEC_MAX)
>+		res->lpi_irq = pci_irq_vector(pdev, plat->msi_lpi_vec);
>+	if (plat->msi_sfty_ce_vec < STMMAC_MSI_VEC_MAX)
>+		res->sfty_ce_irq = pci_irq_vector(pdev, plat-
>>msi_sfty_ce_vec);
>+	if (plat->msi_sfty_ue_vec < STMMAC_MSI_VEC_MAX)
>+		res->sfty_ue_irq = pci_irq_vector(pdev, plat-
>>msi_sfty_ue_vec);
>+
>+	plat->multi_msi_en = 1;
>+	dev_info(&pdev->dev, "%s: multi MSI enablement successful\n",
>__func__);
>+
>+	return 0;
>+}