net/mlx5: Enable single IRQ for PCI Function

Prior to this patch the driver requires two IRQs to function properly,
one required IRQ for control and at least one required IRQ for IO.

This requirement can be relaxed to one as the driver now allows
sharing of IRQs, so control and IO EQs can share the same irq.

This is needed for high scale amount of VFs.

Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
index a66144b..830444f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
@@ -196,6 +196,12 @@
 
 static void irq_set_name(struct mlx5_irq_pool *pool, char *name, int vecidx)
 {
+	if (!pool->xa_num_irqs.max) {
+		/* in case we only have a single irq for the device */
+		snprintf(name, MLX5_MAX_IRQ_NAME, "mlx5_combined%d", vecidx);
+		return;
+	}
+
 	if (vecidx == pool->xa_num_irqs.max) {
 		snprintf(name, MLX5_MAX_IRQ_NAME, "mlx5_async%d", vecidx);
 		return;
@@ -204,6 +210,11 @@
 	snprintf(name, MLX5_MAX_IRQ_NAME, "mlx5_comp%d", vecidx);
 }
 
+static bool irq_pool_is_sf_pool(struct mlx5_irq_pool *pool)
+{
+	return !strncmp("mlx5_sf", pool->name, strlen("mlx5_sf"));
+}
+
 static struct mlx5_irq *irq_request(struct mlx5_irq_pool *pool, int i)
 {
 	struct mlx5_core_dev *dev = pool->dev;
@@ -215,7 +226,7 @@
 	if (!irq)
 		return ERR_PTR(-ENOMEM);
 	irq->irqn = pci_irq_vector(dev->pdev, i);
-	if (!pool->name[0])
+	if (!irq_pool_is_sf_pool(pool))
 		irq_set_name(pool, name, i);
 	else
 		irq_sf_set_name(pool, name, i);
@@ -385,6 +396,9 @@
 	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(0, irq->mask);
 	irq_set_affinity_hint(irq->irqn, irq->mask);
 unlock:
 	mutex_unlock(&pool->lock);
@@ -577,6 +591,8 @@
 
 int mlx5_irq_table_get_num_comp(struct mlx5_irq_table *table)
 {
+	if (!table->pf_pool->xa_num_irqs.max)
+		return 1;
 	return table->pf_pool->xa_num_irqs.max - table->pf_pool->xa_num_irqs.min;
 }
 
@@ -592,19 +608,15 @@
 	if (mlx5_core_is_sf(dev))
 		return 0;
 
-	pf_vec = MLX5_CAP_GEN(dev, num_ports) * num_online_cpus() +
-		 MLX5_IRQ_VEC_COMP_BASE;
+	pf_vec = MLX5_CAP_GEN(dev, num_ports) * num_online_cpus() + 1;
 	pf_vec = min_t(int, pf_vec, num_eqs);
-	if (pf_vec <= MLX5_IRQ_VEC_COMP_BASE)
-		return -ENOMEM;
 
 	total_vec = pf_vec;
 	if (mlx5_sf_max_functions(dev))
 		total_vec += MLX5_IRQ_CTRL_SF_MAX +
 			MLX5_COMP_EQS_PER_SF * mlx5_sf_max_functions(dev);
 
-	total_vec = pci_alloc_irq_vectors(dev->pdev, MLX5_IRQ_VEC_COMP_BASE + 1,
-					  total_vec, PCI_IRQ_MSIX);
+	total_vec = pci_alloc_irq_vectors(dev->pdev, 1, total_vec, PCI_IRQ_MSIX);
 	if (total_vec < 0)
 		return total_vec;
 	pf_vec = min(pf_vec, total_vec);
diff --git a/include/linux/mlx5/eq.h b/include/linux/mlx5/eq.h
index cea6ecb..ea3ff5a 100644
--- a/include/linux/mlx5/eq.h
+++ b/include/linux/mlx5/eq.h
@@ -4,7 +4,6 @@
 #ifndef MLX5_CORE_EQ_H
 #define MLX5_CORE_EQ_H
 
-#define MLX5_IRQ_VEC_COMP_BASE 1
 #define MLX5_NUM_CMD_EQE   (32)
 #define MLX5_NUM_ASYNC_EQE (0x1000)
 #define MLX5_NUM_SPARE_EQE (0x80)