On Thu, 2019-02-28 at 23:37 -0600, Parav Pandit wrote:
> Add a subdev driver to probe the subdev devices and create fake
> netdevice for it.
>
> Signed-off-by: Parav Pandit <pa...@mellanox.com>
> ---
> drivers/net/ethernet/mellanox/mlx5/core/Makefile | 2 +-
> drivers/net/ethernet/mellanox/mlx5/core/main.c | 8 +-
> .../net/ethernet/mellanox/mlx5/core/mlx5_core.h | 3 +
> .../ethernet/mellanox/mlx5/core/subdev_driver.c | 93
> ++++++++++++++++++++++
> 4 files changed, 104 insertions(+), 2 deletions(-)
> create mode 100644
> drivers/net/ethernet/mellanox/mlx5/core/subdev_driver.c
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/Makefile
> b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
> index f218789..c8aeaf1 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/Makefile
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
> @@ -16,7 +16,7 @@ mlx5_core-y := main.o cmd.o debugfs.o fw.o
> eq.o uar.o pagealloc.o \
> transobj.o vport.o sriov.o fs_cmd.o fs_core.o \
> fs_counters.o rl.o lag.o dev.o events.o wq.o lib/gid.o
> \
> lib/devcom.o diag/fs_tracepoint.o diag/fw_tracer.o
> -mlx5_core-$(CONFIG_SUBDEV) += subdev.o
> +mlx5_core-$(CONFIG_SUBDEV) += subdev.o subdev_driver.o
>
> #
> # Netdev basic
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/main.c
> b/drivers/net/ethernet/mellanox/mlx5/core/main.c
> index 5f8cf0d..7dfa8c4 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
> @@ -1548,7 +1548,11 @@ static int __init init(void)
> mlx5e_init();
> #endif
>
> - return 0;
> + err = subdev_register_driver(&mlx5_subdev_driver);
> + if (err)
> + pci_unregister_driver(&mlx5_core_driver);
> +
> + return err;
>
> err_debug:
> mlx5_unregister_debugfs();
> @@ -1557,6 +1561,8 @@ static int __init init(void)
>
> static void __exit cleanup(void)
> {
> + subdev_unregister_driver(&mlx5_subdev_driver);
> +
> #ifdef CONFIG_MLX5_CORE_EN
> mlx5e_cleanup();
> #endif
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
> b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
> index 2a54148..1b733c7 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.h
> @@ -41,12 +41,15 @@
> #include <linux/ptp_clock_kernel.h>
> #include <linux/mlx5/cq.h>
> #include <linux/mlx5/fs.h>
> +#include <linux/subdev_bus.h>
>
> #define DRIVER_NAME "mlx5_core"
> #define DRIVER_VERSION "5.0-0"
>
> extern uint mlx5_core_debug_mask;
>
> +extern struct subdev_driver mlx5_subdev_driver;
> +
> #define mlx5_core_dbg(__dev, format, ...)
> \
> dev_dbg(&(__dev)->pdev->dev, "%s:%d:(pid %d): " format,
> \
> __func__, __LINE__, current->pid,
> \
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/subdev_driver.c
> b/drivers/net/ethernet/mellanox/mlx5/core/subdev_driver.c
> new file mode 100644
> index 0000000..880aa4f
> --- /dev/null
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/subdev_driver.c
> @@ -0,0 +1,93 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2018-19 Mellanox Technologies
> +
> +#include <linux/module.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/subdev_bus.h>
> +#include <linux/subdev_ids.h>
> +#include <linux/etherdevice.h>
> +
> +struct mlx5_subdev_ndev {
> + struct net_device ndev;
> +};
> +
> +static void mlx5_dma_test(struct device *dev)
> +{
> + dma_addr_t pa;
> + void *va;
> +
> + va = dma_alloc_coherent(dev, 4096, &pa, GFP_KERNEL);
> + if (va)
> + dma_free_coherent(dev, 4096, va, pa);
> +}
> +
> +static struct net_device *ndev;
> +
> +static int mlx5e_subdev_open(struct net_device *netdev)
> +{
> + return 0;
> +}
> +
> +static int mlx5e_subdev_close(struct net_device *netdev)
> +{
> + return 0;
> +}
> +
> +static netdev_tx_t
> +mlx5e_subdev_xmit(struct sk_buff *skb, struct net_device *netdev)
> +{
> + return NETDEV_TX_BUSY;
> +}
> +
> +const struct net_device_ops mlx5e_subdev_netdev_ops = {
> + .ndo_open = mlx5e_subdev_open,
> + .ndo_stop = mlx5e_subdev_close,
> + .ndo_start_xmit = mlx5e_subdev_xmit,
> +};
> +
> +static int mlx5_subdev_probe(struct device *dev)
> +{
> + int err;
> +
> + mlx5_dma_test(dev);
Hi Parav, can you please shed some light on how do you plan to
communicate with the parent device ? (pci_dev and it's running driver
instance), We will need to share some resources, such as IRQs/BARs/etc
.., and maybe some HW objects which are going to be managed by the
parent pci device driver.
Just allocating a dma buffer doesn't mean anything, the dma buffer is
just bound to the generic device.
> + /* Only one device supported in rfc */
> + if (ndev)
> + return 0;
> +
> + ndev = alloc_etherdev_mqs(sizeof(struct mlx5_subdev_ndev), 1,
> 1);
> + if (!ndev)
> + return -ENOMEM;
> +
> + SET_NETDEV_DEV(ndev, dev);
> + ndev->netdev_ops = &mlx5e_subdev_netdev_ops;
> + err = register_netdev(ndev);
> + if (err) {
> + free_netdev(ndev);
> + ndev = NULL;
> + }
> + return err;
> +}
> +
> +static int mlx5_subdev_remove(struct device *dev)
> +{
> + if (ndev) {
> + unregister_netdev(ndev);
> + free_netdev(ndev);
> + ndev = NULL;
> + }
> + return 0;
> +}
> +
> +static const struct subdev_id mlx5_subdev_id_table[] = {
> + { .vendor_id = SUBDEV_VENDOR_ID_MELLANOX,
> + .device_id = SUBDEV_DEVICE_ID_MELLANOX_SF },
> + { 0, }
> +};
> +MODULE_DEVICE_TABLE(subdev, mlx5_subdev_id_table);
> +
> +struct subdev_driver mlx5_subdev_driver = {
> + .id_table = mlx5_subdev_id_table,
> + .driver.name = "mlx5_subdev_driver",
> + .driver.probe = mlx5_subdev_probe,
> + .driver.remove = mlx5_subdev_remove,
> +};
