enic: assign affinity hint to interrupts

The affinity hint is used by the user space daemon, irqbalancer, to
indicate a preferred CPU mask for irqs. This patch sets the irq affinity
hint to local numa core first, when exausted we try non-local numa cores.

Also set tx xps cpus mask bassed on affinity hint.

v2: remove the global affinity policy.

Signed-off-by: Govindarajulu Varadarajan <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

Author: Govindarajulu Varadarajan

drivers/net/ethernet/cisco/enic/enic.h

@@ -50,6 +50,7 @@ struct enic_msix_entry {
 	char devname[IFNAMSIZ];
 	irqreturn_t (*isr)(int, void *);
 	void *devid;
+	cpumask_var_t affinity_mask;
 };
 
 /* Store only the lower range.  Higher range is given by fw. */
@@ -263,6 +264,32 @@ static inline unsigned int enic_msix_notify_intr(struct enic *enic)
 	return enic->rq_count + enic->wq_count + 1;
 }
 
+static inline bool enic_is_err_intr(struct enic *enic, int intr)
+{
+	switch (vnic_dev_get_intr_mode(enic->vdev)) {
+	case VNIC_DEV_INTR_MODE_INTX:
+		return intr == enic_legacy_err_intr();
+	case VNIC_DEV_INTR_MODE_MSIX:
+		return intr == enic_msix_err_intr(enic);
+	case VNIC_DEV_INTR_MODE_MSI:
+	default:
+		return false;
+	}
+}
+
+static inline bool enic_is_notify_intr(struct enic *enic, int intr)
+{
+	switch (vnic_dev_get_intr_mode(enic->vdev)) {
+	case VNIC_DEV_INTR_MODE_INTX:
+		return intr == enic_legacy_notify_intr();
+	case VNIC_DEV_INTR_MODE_MSIX:
+		return intr == enic_msix_notify_intr(enic);
+	case VNIC_DEV_INTR_MODE_MSI:
+	default:
+		return false;
+	}
+}
+
 static inline int enic_dma_map_check(struct enic *enic, dma_addr_t dma_addr)
 {
 	if (unlikely(pci_dma_mapping_error(enic->pdev, dma_addr))) {

drivers/net/ethernet/cisco/enic/enic_main.c

@@ -39,6 +39,7 @@
 #include <linux/prefetch.h>
 #include <net/ip6_checksum.h>
 #include <linux/ktime.h>
+#include <linux/numa.h>
 #ifdef CONFIG_RFS_ACCEL
 #include <linux/cpu_rmap.h>
 #endif
@@ -112,6 +113,71 @@ static struct enic_intr_mod_range mod_range[ENIC_MAX_LINK_SPEEDS] = {
 	{3,  6}, /* 10 - 40 Gbps */
 };
 
+static void enic_init_affinity_hint(struct enic *enic)
+{
+	int numa_node = dev_to_node(&enic->pdev->dev);
+	int i;
+
+	for (i = 0; i < enic->intr_count; i++) {
+		if (enic_is_err_intr(enic, i) || enic_is_notify_intr(enic, i) ||
+		    (enic->msix[i].affinity_mask &&
+		     !cpumask_empty(enic->msix[i].affinity_mask)))
+			continue;
+		if (zalloc_cpumask_var(&enic->msix[i].affinity_mask,
+				       GFP_KERNEL))
+			cpumask_set_cpu(cpumask_local_spread(i, numa_node),
+					enic->msix[i].affinity_mask);
+	}
+}
+
+static void enic_free_affinity_hint(struct enic *enic)
+{
+	int i;
+
+	for (i = 0; i < enic->intr_count; i++) {
+		if (enic_is_err_intr(enic, i) || enic_is_notify_intr(enic, i))
+			continue;
+		free_cpumask_var(enic->msix[i].affinity_mask);
+	}
+}
+
+static void enic_set_affinity_hint(struct enic *enic)
+{
+	int i;
+	int err;
+
+	for (i = 0; i < enic->intr_count; i++) {
+		if (enic_is_err_intr(enic, i)		||
+		    enic_is_notify_intr(enic, i)	||
+		    !enic->msix[i].affinity_mask	||
+		    cpumask_empty(enic->msix[i].affinity_mask))
+			continue;
+		err = irq_set_affinity_hint(enic->msix_entry[i].vector,
+					    enic->msix[i].affinity_mask);
+		if (err)
+			netdev_warn(enic->netdev, "irq_set_affinity_hint failed, err %d\n",
+				    err);
+	}
+
+	for (i = 0; i < enic->wq_count; i++) {
+		int wq_intr = enic_msix_wq_intr(enic, i);
+
+		if (enic->msix[wq_intr].affinity_mask &&
+		    !cpumask_empty(enic->msix[wq_intr].affinity_mask))
+			netif_set_xps_queue(enic->netdev,
+					    enic->msix[wq_intr].affinity_mask,
+					    i);
+	}
+}
+
+static void enic_unset_affinity_hint(struct enic *enic)
+{
+	int i;
+
+	for (i = 0; i < enic->intr_count; i++)
+		irq_set_affinity_hint(enic->msix_entry[i].vector, NULL);
+}
+
 int enic_is_dynamic(struct enic *enic)
 {
 	return enic->pdev->device == PCI_DEVICE_ID_CISCO_VIC_ENET_DYN;
@@ -1649,6 +1715,8 @@ static int enic_open(struct net_device *netdev)
 		netdev_err(netdev, "Unable to request irq.\n");
 		return err;
 	}
+	enic_init_affinity_hint(enic);
+	enic_set_affinity_hint(enic);
 
 	err = enic_dev_notify_set(enic);
 	if (err) {
@@ -1701,6 +1769,7 @@ static int enic_open(struct net_device *netdev)
 		vnic_rq_clean(&enic->rq[i], enic_free_rq_buf);
 	enic_dev_notify_unset(enic);
 err_out_free_intr:
+	enic_unset_affinity_hint(enic);
 	enic_free_intr(enic);
 
 	return err;
@@ -1754,6 +1823,7 @@ static int enic_stop(struct net_device *netdev)
 	}
 
 	enic_dev_notify_unset(enic);
+	enic_unset_affinity_hint(enic);
 	enic_free_intr(enic);
 
 	for (i = 0; i < enic->wq_count; i++)
@@ -2309,6 +2379,7 @@ static void enic_dev_deinit(struct enic *enic)
 
 	enic_free_vnic_resources(enic);
 	enic_clear_intr_mode(enic);
+	enic_free_affinity_hint(enic);
 }
 
 static void enic_kdump_kernel_config(struct enic *enic)
@@ -2404,6 +2475,7 @@ static int enic_dev_init(struct enic *enic)
 	return 0;
 
 err_out_free_vnic_resources:
+	enic_free_affinity_hint(enic);
 	enic_clear_intr_mode(enic);
 	enic_free_vnic_resources(enic);