net/mlx5: Introduce API for bulk request and release of IRQs

Currently IRQs are requested one by one. To balance spreading IRQs
among cpus using such scheme requires remembering cpu mask for the
cpus used for a given device. This complicates the IRQ allocation
scheme in subsequent patch.

Hence, prepare the code for bulk IRQs allocation. This enables
spreading IRQs among cpus in subsequent patch.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

1 files changed, 64 insertions, 5 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
index 496826a7a88b..2e19c3c222fe 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
@@ -342,13 +342,27 @@ static struct mlx5_irq_pool *ctrl_irq_pool_get(struct mlx5_core_dev *dev)
 }
 
 /**
- * mlx5_irq_release - release an IRQ back to the system.
- * @irq: irq to be released.
+ * mlx5_irqs_release - release one or more IRQs back to the system.
+ * @irqs: IRQs to be released.
+ * @nirqs: number of IRQs to be released.
  */
-void mlx5_irq_release(struct mlx5_irq *irq)
+static void mlx5_irqs_release(struct mlx5_irq **irqs, int nirqs)
 {
-	synchronize_irq(irq->irqn);
-	irq_put(irq);
+	int i;
+
+	for (i = 0; i < nirqs; i++) {
+		synchronize_irq(irqs[i]->irqn);
+		irq_put(irqs[i]);
+	}
+}
+
+/**
+ * mlx5_ctrl_irq_release - release a ctrl IRQ back to the system.
+ * @ctrl_irq: ctrl IRQ to be released.
+ */
+void mlx5_ctrl_irq_release(struct mlx5_irq *ctrl_irq)
+{
+	mlx5_irqs_release(&ctrl_irq, 1);
 }
 
 /**
@@ -423,6 +437,51 @@ out:
 	return irq;
 }
 
+/**
+ * mlx5_irqs_release_vectors - release one or more IRQs back to the system.
+ * @irqs: IRQs to be released.
+ * @nirqs: number of IRQs to be released.
+ */
+void mlx5_irqs_release_vectors(struct mlx5_irq **irqs, int nirqs)
+{
+	mlx5_irqs_release(irqs, nirqs);
+}
+
+/**
+ * mlx5_irqs_request_vectors - request one or more IRQs for mlx5 device.
+ * @dev: mlx5 device that is requesting the IRQs.
+ * @cpus: CPUs array for binding the IRQs
+ * @nirqs: number of IRQs to request.
+ * @irqs: an output array of IRQs pointers.
+ *
+ * Each IRQ is bound to at most 1 CPU.
+ * This function is requests nirqs IRQs, starting from @vecidx.
+ *
+ * This function returns the number of IRQs requested, (which might be smaller than
+ * @nirqs), if successful, or a negative error code in case of an error.
+ */
+int mlx5_irqs_request_vectors(struct mlx5_core_dev *dev, u16 *cpus, int nirqs,
+			      struct mlx5_irq **irqs)
+{
+	cpumask_var_t req_mask;
+	struct mlx5_irq *irq;
+	int i;
+
+	if (!zalloc_cpumask_var(&req_mask, GFP_KERNEL))
+		return -ENOMEM;
+	for (i = 0; i < nirqs; i++) {
+		cpumask_set_cpu(cpus[i], req_mask);
+		irq = mlx5_irq_request(dev, i, req_mask);
+		if (IS_ERR(irq))
+			break;
+		cpumask_clear(req_mask);
+		irqs[i] = irq;
+	}
+
+	free_cpumask_var(req_mask);
+	return i ? i : PTR_ERR(irq);
+}
+
 static struct mlx5_irq_pool *
 irq_pool_alloc(struct mlx5_core_dev *dev, int start, int size, char *name,
 	       u32 min_threshold, u32 max_threshold)