Re: [PATCH net-next, 3/6] net/mlx5: Add wrappers for HyperV PCIe operations

Eran Ben Elisha
2019-08-15T11:34:47Z

On 8/14/2019 11:41 PM, Mark Bloch wrote:
>
>
> On 8/14/19 12:08 PM, Haiyang Zhang wrote:
>> From: Eran Ben Elisha <eranbe@mellanox.com>
>>
>> Add wrapper functions for HyperV PCIe read / write /
>> block_invalidate_register operations. This will be used as an
>> infrastructure in the downstream patch for software communication.
>>
>> This will be enabled by default if CONFIG_PCI_HYPERV_MINI is set.
>>
>> Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
>> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
>> ---
>> drivers/net/ethernet/mellanox/mlx5/core/Makefile | 1 +
>> drivers/net/ethernet/mellanox/mlx5/core/lib/hv.c | 64 ++++++++++++++++++++++++
>> drivers/net/ethernet/mellanox/mlx5/core/lib/hv.h | 22 ++++++++
>> 3 files changed, 87 insertions(+)
>> create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/lib/hv.c
>> create mode 100644 drivers/net/ethernet/mellanox/mlx5/core/lib/hv.h
>>
>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/Makefile b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
>> index 8b7edaa..a8950b1 100644
>> --- a/drivers/net/ethernet/mellanox/mlx5/core/Makefile
>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/Makefile
>> @@ -45,6 +45,7 @@ mlx5_core-$(CONFIG_MLX5_ESWITCH) += eswitch.o eswitch_offloads.o eswitch_offlo
>> mlx5_core-$(CONFIG_MLX5_MPFS) += lib/mpfs.o
>> mlx5_core-$(CONFIG_VXLAN) += lib/vxlan.o
>> mlx5_core-$(CONFIG_PTP_1588_CLOCK) += lib/clock.o
>> +mlx5_core-$(CONFIG_PCI_HYPERV_MINI) += lib/hv.o
>>
>> #
>> # Ipoib netdev
>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/hv.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/hv.c
>> new file mode 100644
>> index 0000000..cf08d02
>> --- /dev/null
>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/hv.c
>> @@ -0,0 +1,64 @@
>> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
>> +// Copyright (c) 2018 Mellanox Technologies
>> +
>> +#include <linux/hyperv.h>
>> +#include "mlx5_core.h"
>> +#include "lib/hv.h"
>> +
>> +static int mlx5_hv_config_common(struct mlx5_core_dev *dev, void *buf, int len,
>> + int offset, bool read)
>> +{
>> + int rc = -EOPNOTSUPP;
>> + int bytes_returned;
>> + int block_id;
>> +
>> + if (offset % HV_CONFIG_BLOCK_SIZE_MAX || len % HV_CONFIG_BLOCK_SIZE_MAX)
>> + return -EINVAL;
>> +
>> + block_id = offset / HV_CONFIG_BLOCK_SIZE_MAX;
>> +
>> + rc = read ?
>> + hyperv_read_cfg_blk(dev->pdev, buf,
>> + HV_CONFIG_BLOCK_SIZE_MAX, block_id,
>> + &bytes_returned) :
>> + hyperv_write_cfg_blk(dev->pdev, buf,
>> + HV_CONFIG_BLOCK_SIZE_MAX, block_id);
>> +
>> + /* Make sure len bytes were read successfully */
>> + if (read)
>> + rc |= !(len == bytes_returned);
>> +
>> + if (rc) {
>> + mlx5_core_err(dev, "Failed to %s hv config, err = %d, len = %d, offset = %d\n",
>> + read ? "read" : "write", rc, len,
>> + offset);
>> + return rc;
>> + }
>> +
>> + return 0;
>> +}
>
> This seems out of place why not expose this function as part of hyperv and mlx5
> will just pass the pdev.
>
The HV driver works with block chunks. I found it less convenience to do
so directly, so I add a small wrapper for mlx5 core.

Haiyangz,
Do you see a reason to export this callback style from the HYPERV level
instead?

>> +
>> +int mlx5_hv_read_config(struct mlx5_core_dev *dev, void *buf, int len,
>> + int offset)
>> +{
>> + return mlx5_hv_config_common(dev, buf, len, offset, true);
>> +}
>> +
>> +int mlx5_hv_write_config(struct mlx5_core_dev *dev, void *buf, int len,
>> + int offset)
>> +{
>> + return mlx5_hv_config_common(dev, buf, len, offset, false);
>> +}
>> +
>> +int mlx5_hv_register_invalidate(struct mlx5_core_dev *dev, void *context,
>> + void (*block_invalidate)(void *context,
>> + u64 block_mask))
>> +{
>> + return hyperv_reg_block_invalidate(dev->pdev, context,
>> + block_invalidate);
>> +}
>> +
>> +void mlx5_hv_unregister_invalidate(struct mlx5_core_dev *dev)
>> +{
>> + hyperv_reg_block_invalidate(dev->pdev, NULL, NULL);
>> +}
>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/hv.h b/drivers/net/ethernet/mellanox/mlx5/core/lib/hv.h
>> new file mode 100644
>> index 0000000..7f69771
>> --- /dev/null
>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/hv.h
>> @@ -0,0 +1,22 @@
>> +/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
>> +/* Copyright (c) 2019 Mellanox Technologies. */
>> +
>> +#ifndef __LIB_HV_H__
>> +#define __LIB_HV_H__
>> +
>> +#if IS_ENABLED(CONFIG_PCI_HYPERV_MINI)
>> +
>> +#include <linux/hyperv.h>
>> +#include <linux/mlx5/driver.h>
>> +
>> +int mlx5_hv_read_config(struct mlx5_core_dev *dev, void *buf, int len,
>> + int offset);
>> +int mlx5_hv_write_config(struct mlx5_core_dev *dev, void *buf, int len,
>> + int offset);
>> +int mlx5_hv_register_invalidate(struct mlx5_core_dev *dev, void *context,
>> + void (*block_invalidate)(void *context,
>> + u64 block_mask));
>> +void mlx5_hv_unregister_invalidate(struct mlx5_core_dev *dev);
>> +#endif
>> +
>> +#endif /* __LIB_HV_H__ */
>>
>
> Mark
>