Subject: [PATCH net-next 02/15] net/mlx5: Introduce control IRQ request API

From: Saeed Mahameed <[email-masked]>
Date: Thu, 6 Jan 2022 16:29:43 -0800

From: Shay Drory <[email-masked]>

Currently, IRQ layer have a separate flow for ctrl and comp IRQs, and
the distinction between ctrl and comp IRQs is done in the IRQ layer.

In order to ease the coding and maintenance of the IRQ layer,
introduce a new API for requesting control IRQs -
mlx5_ctrl_irq_request(struct mlx5_core_dev *dev).

Signed-off-by: Shay Drory <[email-masked]>
Reviewed-by: Moshe Shemesh <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/eq.c  |  5 +-
 .../ethernet/mellanox/mlx5/core/mlx5_irq.h    |  1 +
 .../net/ethernet/mellanox/mlx5/core/pci_irq.c | 62 ++++++++++++++++---
 3 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
index b695aad71ee1..1eb0326a489b 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
@@ -289,7 +289,10 @@ create_map_eq(struct mlx5_core_dev *dev, struct mlx5_eq *eq,
 	mlx5_init_fbc(eq->frag_buf.frags, log_eq_stride, log_eq_size, &eq->fbc);
 	init_eq_buf(eq);
 
-	eq->irq = mlx5_irq_request(dev, vecidx, param->affinity);
+	if (vecidx == MLX5_IRQ_EQ_CTRL)
+		eq->irq = mlx5_ctrl_irq_request(dev);
+	else
+		eq->irq = mlx5_irq_request(dev, vecidx, param->affinity);
 	if (IS_ERR(eq->irq)) {
 		err = PTR_ERR(eq->irq);
 		goto err_buf;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_irq.h b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_irq.h
index 8116815663a7..7028e4b43837 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_irq.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_irq.h
@@ -22,6 +22,7 @@ int mlx5_set_msix_vec_count(struct mlx5_core_dev *dev, int devfn,
 			    int msix_vec_count);
 int mlx5_get_default_msix_vec_count(struct mlx5_core_dev *dev, int num_vfs);
 
+struct mlx5_irq *mlx5_ctrl_irq_request(struct mlx5_core_dev *dev);
 struct mlx5_irq *mlx5_irq_request(struct mlx5_core_dev *dev, u16 vecidx,
 				  struct cpumask *affinity);
 void mlx5_irq_release(struct mlx5_irq *irq);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
index 163e01fe500e..510a9b91ff9a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
@@ -396,23 +396,36 @@ irq_pool_request_vector(struct mlx5_irq_pool *pool, int vecidx,
 	if (IS_ERR(irq) || !affinity)
 		goto unlock;
 	cpumask_copy(irq->mask, affinity);
-	if (!irq_pool_is_sf_pool(pool) && !pool->xa_num_irqs.max &&
-	    cpumask_empty(irq->mask))
-		cpumask_set_cpu(cpumask_first(cpu_online_mask), irq->mask);
 	irq_set_affinity_hint(irq->irqn, irq->mask);
 unlock:
 	mutex_unlock(&pool->lock);
 	return irq;
 }
 
-static struct mlx5_irq_pool *find_sf_irq_pool(struct mlx5_irq_table *irq_table,
-					      int i, struct cpumask *affinity)
+static struct mlx5_irq_pool *sf_ctrl_irq_pool_get(struct mlx5_irq_table *irq_table)
+{
+	return irq_table->sf_ctrl_pool;
+}
+
+static struct mlx5_irq_pool *sf_irq_pool_get(struct mlx5_irq_table *irq_table)
 {
-	if (cpumask_empty(affinity) && i == MLX5_IRQ_EQ_CTRL)
-		return irq_table->sf_ctrl_pool;
 	return irq_table->sf_comp_pool;
 }
 
+static struct mlx5_irq_pool *ctrl_irq_pool_get(struct mlx5_core_dev *dev)
+{
+	struct mlx5_irq_table *irq_table = mlx5_irq_table_get(dev);
+	struct mlx5_irq_pool *pool = NULL;
+
+	if (mlx5_core_is_sf(dev))
+		pool = sf_ctrl_irq_pool_get(irq_table);
+
+	/* In some configs, there won't be a pool of SFs IRQs. Hence, returning
+	 * the PF IRQs pool in case the SF pool doesn't exist.
+	 */
+	return pool ? pool : irq_table->pf_pool;
+}
+
 /**
  * mlx5_irq_release - release an IRQ back to the system.
  * @irq: irq to be released.
@@ -423,6 +436,38 @@ void mlx5_irq_release(struct mlx5_irq *irq)
 	irq_put(irq);
 }
 
+/**
+ * mlx5_ctrl_irq_request - request a ctrl IRQ for mlx5 device.
+ * @dev: mlx5 device that requesting the IRQ.
+ *
+ * This function returns a pointer to IRQ, or ERR_PTR in case of error.
+ */
+struct mlx5_irq *mlx5_ctrl_irq_request(struct mlx5_core_dev *dev)
+{
+	struct mlx5_irq_pool *pool = ctrl_irq_pool_get(dev);
+	cpumask_var_t req_mask;
+	struct mlx5_irq *irq;
+
+	if (!zalloc_cpumask_var(&req_mask, GFP_KERNEL))
+		return ERR_PTR(-ENOMEM);
+	cpumask_copy(req_mask, cpu_online_mask);
+	if (!irq_pool_is_sf_pool(pool)) {
+		/* In case we are allocating a control IRQ for PF/VF */
+		if (!pool->xa_num_irqs.max) {
+			cpumask_clear(req_mask);
+			/* In case we only have a single IRQ for PF/VF */
+			cpumask_set_cpu(cpumask_first(cpu_online_mask), req_mask);
+		}
+		/* Allocate the IRQ in the last index of the pool */
+		irq = irq_pool_request_vector(pool, pool->xa_num_irqs.max, req_mask);
+	} else {
+		irq = irq_pool_request_affinity(pool, req_mask);
+	}
+
+	free_cpumask_var(req_mask);
+	return irq;
+}
+
 /**
  * mlx5_irq_request - request an IRQ for mlx5 device.
  * @dev: mlx5 device that requesting the IRQ.
@@ -440,7 +485,7 @@ struct mlx5_irq *mlx5_irq_request(struct mlx5_core_dev *dev, u16 vecidx,
 	struct mlx5_irq *irq;
 
 	if (mlx5_core_is_sf(dev)) {
-		pool = find_sf_irq_pool(irq_table, vecidx, affinity);
+		pool = sf_irq_pool_get(irq_table);
 		if (!pool)
 			/* we don't have IRQs for SFs, using the PF IRQs */
 			goto pf_irq;
@@ -453,7 +498,6 @@ struct mlx5_irq *mlx5_irq_request(struct mlx5_core_dev *dev, u16 vecidx,
 	}
 pf_irq:
 	pool = irq_table->pf_pool;
-	vecidx = (vecidx == MLX5_IRQ_EQ_CTRL) ? pool->xa_num_irqs.max : vecidx;
 	irq = irq_pool_request_vector(pool, vecidx, affinity);
 out:
 	if (IS_ERR(irq))
-- 
2.33.1