Re: [dpdk-dev] [PATCH v1 2/8] net/mlx5: add mlx5 Linux specific file with getter functions

[Ophir Munk <ophirmu@mellanox.com>]

Hi Ferruh,
Please see inline

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Monday, June 8, 2020 2:20 PM
> To: Ophir Munk <ophirmu@mellanox.com>; dev@dpdk.org; Matan Azrad
> <matan@mellanox.com>; Raslan Darawsheh <rasland@mellanox.com>
> Subject: Re: [dpdk-dev] [PATCH v1 2/8] net/mlx5: add mlx5 Linux specific file
> with getter functions
> 
> On 6/3/2020 4:05 PM, Ophir Munk wrote:
> > 'ctx' type (field in 'struct mlx5_ctx_shared') is changed from 'struct
> > ibv_context *' to 'void *'.  'ctx' members which are verbs dependent
> > (e.g. device_name) will be accessed through getter functions which are
> > added to a new file under Linux directory: linux/mlx5_os.c.
> >
> > Signed-off-by: Ophir Munk <ophirmu@mellanox.com>
> > Acked-by: Matan Azrad <matan@mellanox.com>
> 
> <...>
> 
> > @@ -0,0 +1,87 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright 2015 6WIND S.A.
> > + * Copyright 2020 Mellanox Technologies, Ltd  */
> 
> Just to double check if '6WIND' is copy/paste error in this new file?
> 

Some functions were moved from file mlx5.c (with 6WIND copyright) to this file
and renamed. 
Should 6WIND copyright be kept or removed in this file (mlx5_os.c)?

> <...>
> 
> > @@ -677,13 +677,14 @@ mlx5_dev_shared_handler_install(struct
> mlx5_dev_ctx_shared *sh)
> >  	int flags;
> >
> >  	sh->intr_handle.fd = -1;
> > -	flags = fcntl(sh->ctx->async_fd, F_GETFL);
> > -	ret = fcntl(sh->ctx->async_fd, F_SETFL, flags | O_NONBLOCK);
> > +	flags = fcntl(((struct ibv_context *)sh->ctx)->async_fd, F_GETFL);
> > +	ret = fcntl(((struct ibv_context *)sh->ctx)->async_fd,
> > +		    F_SETFL, flags | O_NONBLOCK);
> 
> As far as I understand you are trying to remove to the dependency to ibverbs,
> at least in root level, linux/x.c will have that dependency. (I assume this is for
> Windows support) The 'mlx5_os_get_ctx_device_path()' wrapper seems can
> work for it but what is the point of above usage, that you explicitly cast "void
> *" to "(struct ibv_context *)", so you still keep the ibv dependency?

The reason for keeping an explicit cast for async_fd (and not creating a new getter API)
is that this code snippet will be moved under linux in next commits where no getter function is needed.
I wanted to avoid adding a getter function here and then remove it in a follow up commit.