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From: Jason Gunthorpe <jgg@nvidia.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Leon Romanovsky <leon@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Saeed Mahameed <saeedm@nvidia.com>,
	Alexander Duyck <alexander.duyck@gmail.com>,
	Jakub Kicinski <kuba@kernel.org>, <linux-pci@vger.kernel.org>,
	<linux-rdma@vger.kernel.org>, <netdev@vger.kernel.org>,
	Don Dutile <ddutile@redhat.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH mlx5-next v6 1/4] PCI: Add sysfs callback to allow MSI-X table size change of SR-IOV VFs
Date: Tue, 16 Feb 2021 16:37:26 -0400	[thread overview]
Message-ID: <20210216203726.GH4247@nvidia.com> (raw)
In-Reply-To: <20210216161212.GA805748@bjorn-Precision-5520>

On Tue, Feb 16, 2021 at 10:12:12AM -0600, Bjorn Helgaas wrote:
> > >
> > > But I still don't like the fact that we're calling
> > > sysfs_create_files() and sysfs_remove_files() directly.  It makes
> > > complication and opportunities for errors.
> > 
> > It is not different from any other code that we have in the kernel.
> 
> It *is* different.  There is a general rule that drivers should not
> call sysfs_* [1].  The PCI core is arguably not a "driver," but it is
> still true that callers of sysfs_create_files() are very special, and
> I'd prefer not to add another one.

I think the point of [1] is people should be setting up their sysfs in
the struct device attribute groups/etc before doing device_add() and
allowing the driver core to handle everything. This can be done in
a lot of cases, eg we have examples of building a dynamic list of
attributes

In other cases, calling wrappers like device_create_file() introduces
a bit more type safety, so adding a device_create_files() would be
trivial enough

Other places in PCI are using syfs_create_group() (and there are over
400 calls to this function in all sorts of device drivers):

drivers/pci/msi.c:      ret = sysfs_create_groups(&pdev->dev.kobj, msi_irq_groups);
drivers/pci/p2pdma.c:   error = sysfs_create_group(&pdev->dev.kobj, &p2pmem_group);
drivers/pci/pci-label.c:        return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
drivers/pci/pci-label.c:        return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);

For post-driver_add() stuff, maybe this should do the same, a
"srio_vf/" group?

And a minor cleanup would change these to use device_create_bin_file():

drivers/pci/pci-sysfs.c:        retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
drivers/pci/pci-sysfs.c:                retval = sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
drivers/pci/pci-sysfs.c:                retval = sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
drivers/pci/pci-sysfs.c:                retval = sysfs_create_bin_file(&pdev->dev.kobj, attr);
drivers/pci/vpd.c:      retval = sysfs_create_bin_file(&dev->dev.kobj, attr);

I haven't worked out why pci_create_firmware_label_files() and all of
this needs to be after device_add() though.. Would be slick to put
that in the normal attribute list - we've got some examples of dynamic
pre-device_add() attribute lists in the tree (eg tpm, rdma) that work
nicely.

Jason

  parent reply	other threads:[~2021-02-16 20:38 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-09 13:34 [PATCH mlx5-next v6 0/4] Dynamically assign MSI-X vectors count Leon Romanovsky
2021-02-09 13:34 ` [PATCH mlx5-next v6 1/4] PCI: Add sysfs callback to allow MSI-X table size change of SR-IOV VFs Leon Romanovsky
2021-02-15 21:01   ` Bjorn Helgaas
2021-02-16  7:33     ` Leon Romanovsky
2021-02-16 16:12       ` Bjorn Helgaas
2021-02-16 19:58         ` Leon Romanovsky
2021-02-17 18:02           ` Bjorn Helgaas
2021-02-17 19:25             ` Jason Gunthorpe
2021-02-17 20:28               ` Bjorn Helgaas
2021-02-17 23:52                 ` Jason Gunthorpe
2021-02-18 10:15             ` Leon Romanovsky
2021-02-18 22:39               ` Bjorn Helgaas
2021-02-19  7:52                 ` Leon Romanovsky
2021-02-19  8:20                   ` Greg Kroah-Hartman
2021-02-19 16:58                     ` Leon Romanovsky
2021-02-20 19:06                     ` Bjorn Helgaas
2021-02-21  6:59                       ` Leon Romanovsky
2021-02-23 21:07                         ` Bjorn Helgaas
2021-02-24  8:09                           ` Greg Kroah-Hartman
2021-02-24 21:37                             ` Don Dutile
2021-02-24  9:53                           ` Leon Romanovsky
2021-02-24 15:07                             ` Bjorn Helgaas
2021-02-21 13:00                       ` Greg Kroah-Hartman
2021-02-21 13:55                         ` Leon Romanovsky
2021-02-21 15:01                           ` Greg Kroah-Hartman
2021-02-21 15:30                             ` Leon Romanovsky
2021-02-16 20:37         ` Jason Gunthorpe [this message]
2021-02-09 13:34 ` [PATCH mlx5-next v6 2/4] net/mlx5: Add dynamic MSI-X capabilities bits Leon Romanovsky
2021-02-09 13:34 ` [PATCH mlx5-next v6 3/4] net/mlx5: Dynamically assign MSI-X vectors count Leon Romanovsky
2021-02-09 13:34 ` [PATCH mlx5-next v6 4/4] net/mlx5: Allow to the users to configure number of MSI-X vectors Leon Romanovsky
2021-02-09 21:06 ` [PATCH mlx5-next v6 0/4] Dynamically assign MSI-X vectors count Alexander Duyck
2021-02-14  5:24   ` Leon Romanovsky

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