Re: [PATCH v4] vdpa/octeon_ep: Control PCI dev enabling manually

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, May 15, 2025 at 09:14:22AM +0200, Philipp Stanner wrote:
> On Thu, 2025-05-08 at 10:51 +0200, Philipp Stanner wrote:
> > PCI region request functions such as pci_request_region() currently
> > have
> > the problem of becoming sometimes managed functions, if
> > pcim_enable_device() instead of pci_enable_device() was called. The
> > PCI
> > subsystem wants to remove this deprecated behavior from its
> > interfaces.
> > 
> > octeopn_ep enables its device with pcim_enable_device() (for VF. PF
> > uses
> > manual management), but does so only to get automatic disablement.
> > The
> > driver wants to manage its PCI resources for VF manually, without
> > devres.
> > 
> > The easiest way not to use automatic resource management at all is by
> > also handling device enable- and disablement manually.
> > 
> > Replace pcim_enable_device() with pci_enable_device(). Add the
> > necessary
> > calls to pci_disable_device().
> > 
> > Signed-off-by: Philipp Stanner <phasta@kernel.org>
> > Acked-by: Vamsi Attunuru <vattunuru@marvell.com>
> 
> Hi again,
> 
> this is the last of 12 drivers blocking me from removing a few hundred
> lines of broken code from PCI. Would be great if it could be sent to
> Linus next merge window.
> 
> Can someone take this patch in?
> 
> Thx
> P.

I intend to, working on packing things up for -next as we speak.

> > ---
> > Changes in v4:
> >   - s/AF/PF
> >   - Add Vamsi's AB
> > 
> > Changes in v3:
> >   - Only call pci_disable_device() for the PF version. For AF it
> > would
> >     cause a WARN_ON because pcim_enable_device()'s callback will also
> >     try to disable.
> > ---
> >  drivers/vdpa/octeon_ep/octep_vdpa_main.c | 17 ++++++++++++-----
> >  1 file changed, 12 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/vdpa/octeon_ep/octep_vdpa_main.c
> > b/drivers/vdpa/octeon_ep/octep_vdpa_main.c
> > index f3d4dda4e04c..9b49efd24391 100644
> > --- a/drivers/vdpa/octeon_ep/octep_vdpa_main.c
> > +++ b/drivers/vdpa/octeon_ep/octep_vdpa_main.c
> > @@ -454,6 +454,9 @@ static void octep_vdpa_remove_pf(struct pci_dev
> > *pdev)
> >  		octep_iounmap_region(pdev, octpf->base,
> > OCTEP_HW_MBOX_BAR);
> >  
> >  	octep_vdpa_pf_bar_expand(octpf);
> > +
> > +	/* The pf version does not use managed PCI. */
> > +	pci_disable_device(pdev);
> >  }
> >  
> >  static void octep_vdpa_vf_bar_shrink(struct pci_dev *pdev)
> > @@ -825,7 +828,7 @@ static int octep_vdpa_probe_pf(struct pci_dev
> > *pdev)
> >  	struct octep_pf *octpf;
> >  	int ret;
> >  
> > -	ret = pcim_enable_device(pdev);
> > +	ret = pci_enable_device(pdev);
> >  	if (ret) {
> >  		dev_err(dev, "Failed to enable device\n");
> >  		return ret;
> > @@ -834,15 +837,17 @@ static int octep_vdpa_probe_pf(struct pci_dev
> > *pdev)
> >  	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
> >  	if (ret) {
> >  		dev_err(dev, "No usable DMA configuration\n");
> > -		return ret;
> > +		goto disable_pci;
> >  	}
> >  	octpf = devm_kzalloc(dev, sizeof(*octpf), GFP_KERNEL);
> > -	if (!octpf)
> > -		return -ENOMEM;
> > +	if (!octpf) {
> > +		ret = -ENOMEM;
> > +		goto disable_pci;
> > +	}
> >  
> >  	ret = octep_iomap_region(pdev, octpf->base,
> > OCTEP_HW_MBOX_BAR);
> >  	if (ret)
> > -		return ret;
> > +		goto disable_pci;
> >  
> >  	pci_set_master(pdev);
> >  	pci_set_drvdata(pdev, octpf);
> > @@ -856,6 +861,8 @@ static int octep_vdpa_probe_pf(struct pci_dev
> > *pdev)
> >  
> >  unmap_region:
> >  	octep_iounmap_region(pdev, octpf->base, OCTEP_HW_MBOX_BAR);
> > +disable_pci:
> > +	pci_disable_device(pdev);
> >  	return ret;
> >  }
> >