mlx4: Add blue flame support for kernel consumers

Using blue flame can improve latency by allowing the HW to more efficiently
access the WQE. This patch presents two functions that are used to allocate or
release HW resources for using blue flame; the caller need to supply a struct
mlx4_bf object when allocating resources. Consumers that make use of this API
should post doorbells to the UAR object pointed by the initialized struct
mlx4_bf;

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/net/mlx4/main.c b/drivers/net/mlx4/main.c
index c8e276138f8..05c5671749a 100644
--- a/drivers/net/mlx4/main.c
+++ b/drivers/net/mlx4/main.c
@@ -39,6 +39,7 @@
 #include <linux/pci.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
+#include <linux/io-mapping.h>
 
 #include <linux/mlx4/device.h>
 #include <linux/mlx4/doorbell.h>
@@ -721,8 +722,31 @@ static void mlx4_free_icms(struct mlx4_dev *dev)
         mlx4_free_icm(dev, priv->fw.aux_icm, 0);
 }
 
+static int map_bf_area(struct mlx4_dev *dev)
+{
+        struct mlx4_priv *priv = mlx4_priv(dev);
+        resource_size_t bf_start;
+        resource_size_t bf_len;
+        int err = 0;
+
+        bf_start = pci_resource_start(dev->pdev, 2) + (dev->caps.num_uars << PAGE_SHIFT);
+        bf_len = pci_resource_len(dev->pdev, 2) - (dev->caps.num_uars << PAGE_SHIFT);
+        priv->bf_mapping = io_mapping_create_wc(bf_start, bf_len);
+        if (!priv->bf_mapping)
+                err = -ENOMEM;
+
+        return err;
+}
+
+static void unmap_bf_area(struct mlx4_dev *dev)
+{
+        if (mlx4_priv(dev)->bf_mapping)
+                io_mapping_free(mlx4_priv(dev)->bf_mapping);
+}
+
 static void mlx4_close_hca(struct mlx4_dev *dev)
 {
+        unmap_bf_area(dev);
         mlx4_CLOSE_HCA(dev, 0);
         mlx4_free_icms(dev);
         mlx4_UNMAP_FA(dev);
@@ -775,6 +799,9 @@ static int mlx4_init_hca(struct mlx4_dev *dev)
                 goto err_stop_fw;
         }
 
+        if (map_bf_area(dev))
+                mlx4_dbg(dev, "Failed to map blue flame area\n");
+
         init_hca.log_uar_sz = ilog2(dev->caps.num_uars);
 
         err = mlx4_init_icm(dev, &dev_cap, &init_hca, icm_size);
@@ -805,6 +832,7 @@ err_free_icm:
         mlx4_free_icms(dev);
 
 err_stop_fw:
+        unmap_bf_area(dev);
         mlx4_UNMAP_FA(dev);
         mlx4_free_icm(dev, priv->fw.fw_icm, 0);
 
@@ -1196,6 +1224,9 @@ static int __mlx4_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
         pci_read_config_byte(pdev, PCI_REVISION_ID, &dev->rev_id);
 
+        INIT_LIST_HEAD(&priv->bf_list);
+        mutex_init(&priv->bf_mutex);
+
         /*
          * Now reset the HCA before we touch the PCI capabilities or
          * attempt a firmware command, since a boot ROM may have left