mlx4: Structures and init/teardown for VF resource quotas

This is step #1 for implementing SRIOV resource quotas for VFs.

Quotas are implemented per resource type for VFs and the PF, to prevent
any entity from simply grabbing all the resources for itself and leaving
the other entities unable to obtain such resources.

Resources which are allocated using quotas:  QPs, CQs, SRQs, MPTs, MTTs, MAC,
                                             VLAN, and Counters.

The quota system works as follows:
Each entity (VF or PF) is given a max number of a given resource (its quota),
and a guaranteed minimum number for each resource (starvation prevention).

For QPs, CQs, SRQs, MPTs and MTTs:
50% of the available quantity for the resource is divided equally among
the PF and all the active VFs (i.e., the number of VFs in the mlx4_core module
parameter "num_vfs"). This 50% represents the "guaranteed minimum" pool.
The other 50% is the "free pool", allocated on a first-come-first-serve basis.
For each VF/PF, resources are first allocated from its "guaranteed-minimum"
pool. When that pool is exhausted, the driver attempts to allocate from
the resource "free-pool".

The quota (i.e., max) for the VFs and the PF is:
  The free-pool amount (50% of the real max) + the guaranteed minimum

For MACs:
  Guarantee 2 MACs per VF/PF per port. As a result, since we have only
  128 MACs per port, reduce the allowable number of VFs from 64 to 63.
  Any remaining MACs are put into a free pool.

For VLANs:
  For the PF, the per-port quota is 128 and guarantee is 64
     (to allow the PF to register at least a VLAN per VF in VST mode).
  For the VFs, the per-port quota is 64 and the guarantee is 0.
      We assume that VGT VFs are trusted not to abuse the VLAN resource.

For Counters:
  For all functions (PF and VFs), the quota is 128 and the guarantee is 0.

In this patch, we define the needed structures, which are added to the
resource-tracker struct.  In addition, we do initialization
for the resource quota, and adjust the query_device response to use quotas
rather than resource maxima.

As part of the implementation, we introduce a new field in
mlx4_dev: quotas.  This field holds the resource quotas used
to report maxima to the upper layers (ib_core, via query_device).

The HCA maxima of these values are passed to the VFs (via
QUERY_HCA) so that they may continue to use these in handling
QPs, CQs, SRQs and MPTs.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index e2e92885bdc1..f6f59271f857 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -641,12 +641,23 @@ struct mlx4_counter {
         __be64  tx_bytes;
 };
 
+struct mlx4_quotas {
+        int qp;
+        int cq;
+        int srq;
+        int mpt;
+        int mtt;
+        int counter;
+        int xrcd;
+};
+
 struct mlx4_dev {
         struct pci_dev         *pdev;
         unsigned long           flags;
         unsigned long           num_slaves;
         struct mlx4_caps        caps;
         struct mlx4_phys_caps   phys_caps;
+        struct mlx4_quotas      quotas;
         struct radix_tree_root  qp_table_tree;
         u8                      rev_id;
         char                    board_id[MLX4_BOARD_ID_LEN];
@@ -772,6 +783,12 @@ static inline int mlx4_is_master(struct mlx4_dev *dev)
         return dev->flags & MLX4_FLAG_MASTER;
 }
 
+static inline int mlx4_num_reserved_sqps(struct mlx4_dev *dev)
+{
+        return dev->phys_caps.base_sqpn + 8 +
+                16 * MLX4_MFUNC_MAX * !!mlx4_is_master(dev);
+}
+
 static inline int mlx4_is_qp_reserved(struct mlx4_dev *dev, u32 qpn)
 {
         return (qpn < dev->phys_caps.base_sqpn + 8 +