mlx4_core: Add support for multiple completion event vectors

When using MSI-X mode, create a completion event queue for each CPU.
Report the number of completion EQs in a new struct mlx4_caps member,
num_comp_vectors, and extend the mlx4_cq_alloc() interface with a
vector parameter so that consumers can specify which completion EQ
should be used to report events for the CQ being created.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 39 insertions, 14 deletions

diff --git a/drivers/net/mlx4/main.c b/drivers/net/mlx4/main.c
index 90a0281d15ea..710c79e7a2db 100644
--- a/drivers/net/mlx4/main.c
+++ b/drivers/net/mlx4/main.c
@@ -421,9 +421,7 @@ static int mlx4_init_cmpt_table(struct mlx4_dev *dev, u64 cmpt_base,
                                   ((u64) (MLX4_CMPT_TYPE_EQ *
                                           cmpt_entry_sz) << MLX4_CMPT_SHIFT),
                                   cmpt_entry_sz,
-                                  roundup_pow_of_two(MLX4_NUM_EQ +
-                                                     dev->caps.reserved_eqs),
-                                  MLX4_NUM_EQ + dev->caps.reserved_eqs, 0, 0);
+                                  dev->caps.num_eqs, dev->caps.num_eqs, 0, 0);
         if (err)
                 goto err_cq;
 
@@ -810,12 +808,12 @@ static int mlx4_setup_hca(struct mlx4_dev *dev)
                 if (dev->flags & MLX4_FLAG_MSI_X) {
                         mlx4_warn(dev, "NOP command failed to generate MSI-X "
                                   "interrupt IRQ %d).\n",
-                                  priv->eq_table.eq[MLX4_EQ_ASYNC].irq);
+                                  priv->eq_table.eq[dev->caps.num_comp_vectors].irq);
                         mlx4_warn(dev, "Trying again without MSI-X.\n");
                 } else {
                         mlx4_err(dev, "NOP command failed to generate interrupt "
                                  "(IRQ %d), aborting.\n",
-                                 priv->eq_table.eq[MLX4_EQ_ASYNC].irq);
+                                 priv->eq_table.eq[dev->caps.num_comp_vectors].irq);
                         mlx4_err(dev, "BIOS or ACPI interrupt routing problem?\n");
                 }
 
@@ -908,31 +906,50 @@ err_uar_table_free:
 static void mlx4_enable_msi_x(struct mlx4_dev *dev)
 {
         struct mlx4_priv *priv = mlx4_priv(dev);
-        struct msix_entry entries[MLX4_NUM_EQ];
+        struct msix_entry *entries;
+        int nreq;
         int err;
         int i;
 
         if (msi_x) {
-                for (i = 0; i < MLX4_NUM_EQ; ++i)
+                nreq = min(dev->caps.num_eqs - dev->caps.reserved_eqs,
+                           num_possible_cpus() + 1);
+                entries = kcalloc(nreq, sizeof *entries, GFP_KERNEL);
+                if (!entries)
+                        goto no_msi;
+
+                for (i = 0; i < nreq; ++i)
                         entries[i].entry = i;
 
-                err = pci_enable_msix(dev->pdev, entries, ARRAY_SIZE(entries));
+        retry:
+                err = pci_enable_msix(dev->pdev, entries, nreq);
                 if (err) {
-                        if (err > 0)
-                                mlx4_info(dev, "Only %d MSI-X vectors available, "
-                                          "not using MSI-X\n", err);
+                        /* Try again if at least 2 vectors are available */
+                        if (err > 1) {
+                                mlx4_info(dev, "Requested %d vectors, "
+                                          "but only %d MSI-X vectors available, "
+                                          "trying again\n", nreq, err);
+                                nreq = err;
+                                goto retry;
+                        }
+
                         goto no_msi;
                 }
 
-                for (i = 0; i < MLX4_NUM_EQ; ++i)
+                dev->caps.num_comp_vectors = nreq - 1;
+                for (i = 0; i < nreq; ++i)
                         priv->eq_table.eq[i].irq = entries[i].vector;
 
                 dev->flags |= MLX4_FLAG_MSI_X;
+
+                kfree(entries);
                 return;
         }
 
 no_msi:
-        for (i = 0; i < MLX4_NUM_EQ; ++i)
+        dev->caps.num_comp_vectors = 1;
+
+        for (i = 0; i < 2; ++i)
                 priv->eq_table.eq[i].irq = dev->pdev->irq;
 }
 
@@ -1074,6 +1091,10 @@ static int __mlx4_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
         if (err)
                 goto err_cmd;
 
+        err = mlx4_alloc_eq_table(dev);
+        if (err)
+                goto err_close;
+
         mlx4_enable_msi_x(dev);
 
         err = mlx4_setup_hca(dev);
@@ -1084,7 +1105,7 @@ static int __mlx4_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
         }
 
         if (err)
-                goto err_close;
+                goto err_free_eq;
 
         for (port = 1; port <= dev->caps.num_ports; port++) {
                 err = mlx4_init_port_info(dev, port);
@@ -1114,6 +1135,9 @@ err_port:
         mlx4_cleanup_pd_table(dev);
         mlx4_cleanup_uar_table(dev);
 
+err_free_eq:
+        mlx4_free_eq_table(dev);
+
 err_close:
         if (dev->flags & MLX4_FLAG_MSI_X)
                 pci_disable_msix(pdev);
@@ -1177,6 +1201,7 @@ static void mlx4_remove_one(struct pci_dev *pdev)
                 iounmap(priv->kar);
                 mlx4_uar_free(dev, &priv->driver_uar);
                 mlx4_cleanup_uar_table(dev);
+                mlx4_free_eq_table(dev);
                 mlx4_close_hca(dev);
                 mlx4_cmd_cleanup(dev);