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 <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index 0c22fd0..b36643e 100644
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/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 @@
 	{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 @@
 		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 @@
 		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 @@
 	}
 
 	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 @@
 
 	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 @@
 	return 0;
 
 err_out_free_vnic_resources:
+	enic_free_affinity_hint(enic);
 	enic_clear_intr_mode(enic);
 	enic_free_vnic_resources(enic);