Re: [PATCH -next v2] PCI: endpoint: pci-epf-vntb: fix error handle in epf_ntb_mw_bar_init()

[Jon Mason]

On Mon, Jun 27, 2022 at 03:27:04PM -0500, Bjorn Helgaas wrote:
> On Sat, Jun 25, 2022 at 10:15:16AM +0800, Yang Yingliang wrote:
> > In error case of epf_ntb_mw_bar_init(), memory window BARs should be
> > cleared, so add 'num_mws' parameter in epf_ntb_mw_bar_clear() and
> > calling it in error path to clear the BARs. Also add missing error
> > code when pci_epc_mem_alloc_addr() fails.
> 
> Another one for Jon, since ff32fac00d97 appeared in -next via his
> tree
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=ff32fac00d97

Sorry for the extremely long delay in response.  This series is in my
ntb branch and will be in my pull request for v5.20 which should be
going out later today.

Thanks,
Jon

> 
> > Fixes: ff32fac00d97 ("NTB: EPF: support NTB transfer between PCI RC and EP connection")
> > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> > Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
> > ---
> > v2:
> >   add error label err_set_bar and move pci_epc_clear_bar() to it
> > ---
> >  drivers/pci/endpoint/functions/pci-epf-vntb.c | 20 ++++++++++++++-----
> >  1 file changed, 15 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > index ebf7e243eefa..ee9fee167d48 100644
> > --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> > @@ -567,6 +567,8 @@ static int epf_ntb_db_bar_init(struct epf_ntb *ntb)
> >  	return -1;
> >  }
> >  
> > +static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws);
> > +
> >  /**
> >   * epf_ntb_db_bar_clear() - Clear doorbell BAR and free memory
> >   *   allocated in peers outbound address space
> > @@ -625,13 +627,21 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
> >  							      &ntb->vpci_mw_phy[i],
> >  							      size);
> >  		if (!ntb->vpci_mw_addr[i]) {
> > +			ret = -ENOMEM;
> >  			dev_err(dev, "Failed to allocate source address\n");
> > -			goto err_alloc_mem;
> > +			goto err_set_bar;
> >  		}
> >  	}
> >  
> >  	return ret;
> > +
> > +err_set_bar:
> > +	pci_epc_clear_bar(ntb->epf->epc,
> > +			  ntb->epf->func_no,
> > +			  ntb->epf->vfunc_no,
> > +			  &ntb->epf->bar[barno]);
> >  err_alloc_mem:
> > +	epf_ntb_mw_bar_clear(ntb, i);
> >  	return ret;
> >  }
> >  
> > @@ -640,12 +650,12 @@ static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
> >   * @ntb: NTB device that facilitates communication between HOST and vHOST
> >   *
> >   */
> > -static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb)
> > +static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
> >  {
> >  	enum pci_barno barno;
> >  	int i;
> >  
> > -	for (i = 0; i < ntb->num_mws; i++) {
> > +	for (i = 0; i < num_mws; i++) {
> >  		barno = ntb->epf_ntb_bar[BAR_MW0 + i];
> >  		pci_epc_clear_bar(ntb->epf->epc,
> >  				  ntb->epf->func_no,
> > @@ -774,7 +784,7 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
> >  	return 0;
> >  
> >  err_write_header:
> > -	epf_ntb_mw_bar_clear(ntb);
> > +	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
> >  err_mw_bar_init:
> >  	epf_ntb_db_bar_clear(ntb);
> >  err_db_bar_init:
> > @@ -794,7 +804,7 @@ static int epf_ntb_epc_init(struct epf_ntb *ntb)
> >  static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
> >  {
> >  	epf_ntb_db_bar_clear(ntb);
> > -	epf_ntb_mw_bar_clear(ntb);
> > +	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
> >  }
> >  
> >  #define EPF_NTB_R(_name)						\
> > -- 
> > 2.25.1
> >