net/mlx5: Add reserved-gids support

Reserved GIDs are entries in the GID table in use by the mlx5_core
and its submodules (e.g. FPGA, SRIOV, E-Swtich, netdev).
The entries are reserved at the high indexes of the GID table.

A mlx5 submodule may reserve a certain amount of GIDs for its own use
during the load sequence by calling mlx5_core_reserve_gids, and must
also take care to un-reserve these GIDs when it closes.
Reservation is only allowed during the load sequence and before any
interfaces (e.g. mlx5_ib or mlx5_en) are up.

After reservation, a submodule may call mlx5_core_reserved_gid_alloc/
free to allocate entries from the reserved GIDs pool.

Reserve a GID table entry for every supported FPGA QP.

A later patch in the patchset will remove them from being reported to
IB core.
Another such patch will make use of these for FPGA QPs in Innova NIC.

Added lib/mlx5.h to serve as a library for mlx5 submodlues, and to
expose only public mlx5 API, more mlx5 library files will be added in
future submissions.

Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

2 files changed, 35 insertions, 1 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fpga/core.c b/drivers/net/ethernet/mellanox/mlx5/core/fpga/core.c
index d88b332e9669..92d8b1b6e598 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/core.c
@@ -35,6 +35,7 @@
 #include <linux/mlx5/driver.h>
 
 #include "mlx5_core.h"
+#include "lib/mlx5.h"
 #include "fpga/core.h"
 
 static const char *const mlx5_fpga_error_strings[] = {
@@ -104,6 +105,7 @@ int mlx5_fpga_device_start(struct mlx5_core_dev *mdev)
 {
 	struct mlx5_fpga_device *fdev = mdev->fpga;
 	unsigned long flags;
+	unsigned int max_num_qps;
 	int err;
 
 	if (!fdev)
@@ -123,6 +125,9 @@ int mlx5_fpga_device_start(struct mlx5_core_dev *mdev)
 		       mlx5_fpga_image_name(fdev->last_oper_image),
 		       MLX5_CAP_FPGA(fdev->mdev, image_version));
 
+	max_num_qps = MLX5_CAP_FPGA(mdev, shell_caps.max_num_qps);
+	err = mlx5_core_reserve_gids(mdev, max_num_qps);
+
 out:
 	spin_lock_irqsave(&fdev->state_lock, flags);
 	fdev->state = err ? MLX5_FPGA_STATUS_FAILURE : MLX5_FPGA_STATUS_SUCCESS;
@@ -151,9 +156,33 @@ int mlx5_fpga_device_init(struct mlx5_core_dev *mdev)
 	return 0;
 }
 
+void mlx5_fpga_device_stop(struct mlx5_core_dev *mdev)
+{
+	struct mlx5_fpga_device *fdev = mdev->fpga;
+	unsigned int max_num_qps;
+	unsigned long flags;
+
+	if (!fdev)
+		return;
+
+	spin_lock_irqsave(&fdev->state_lock, flags);
+	if (fdev->state != MLX5_FPGA_STATUS_SUCCESS) {
+		spin_unlock_irqrestore(&fdev->state_lock, flags);
+		return;
+	}
+	fdev->state = MLX5_FPGA_STATUS_NONE;
+	spin_unlock_irqrestore(&fdev->state_lock, flags);
+
+	max_num_qps = MLX5_CAP_FPGA(mdev, shell_caps.max_num_qps);
+	mlx5_core_unreserve_gids(mdev, max_num_qps);
+}
+
 void mlx5_fpga_device_cleanup(struct mlx5_core_dev *mdev)
 {
-	kfree(mdev->fpga);
+	struct mlx5_fpga_device *fdev = mdev->fpga;
+
+	mlx5_fpga_device_stop(mdev);
+	kfree(fdev);
 	mdev->fpga = NULL;
 }
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fpga/core.h b/drivers/net/ethernet/mellanox/mlx5/core/fpga/core.h
index c55044d66778..557d83973ade 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/core.h
@@ -71,6 +71,7 @@ struct mlx5_fpga_device {
 int mlx5_fpga_device_init(struct mlx5_core_dev *mdev);
 void mlx5_fpga_device_cleanup(struct mlx5_core_dev *mdev);
 int mlx5_fpga_device_start(struct mlx5_core_dev *mdev);
+void mlx5_fpga_device_stop(struct mlx5_core_dev *mdev);
 void mlx5_fpga_event(struct mlx5_core_dev *mdev, u8 event, void *data);
 
 #else
@@ -89,6 +90,10 @@ static inline int mlx5_fpga_device_start(struct mlx5_core_dev *mdev)
 	return 0;
 }
 
+static inline void mlx5_fpga_device_stop(struct mlx5_core_dev *mdev)
+{
+}
+
 static inline void mlx5_fpga_event(struct mlx5_core_dev *mdev, u8 event,
 				   void *data)
 {