On Fri, Mar 15, 2024 at 10:50:45AM +0530, Manivannan Sadhasivam wrote:
> On Wed, Mar 13, 2024 at 11:57:53AM +0100, Niklas Cassel wrote:
> > pci_epf_test_alloc_space() currently skips the BAR succeeding a 64-bit BAR
> > if the 64-bit flag is set, before calling pci_epf_alloc_space().
> >
> > However, pci_epf_alloc_space() will set the 64-bit flag if we request an
> > allocation of 4 GB or larger, even if it wasn't set before the allocation.
> >
>
> Max BAR size is 1MB currently, so I believe you are adding the check just for
> the sake of correctness. If so, please mention it explicitly.
The BAR size defined in:
static size_t bar_size[] = { 512, 512, 1024, 16384, 131072, 1048576 };
will only be used if the BAR is not fixed size.
(A fixed BAR size will override the size in static size_t bar_size[])
So a platform could have a fixed size BAR of e.g. 4GB.
Although, you could argue that if a platform has a fixed BAR size of 4GB,
they should have also marked the BAR as "only 64-bit".
(Considering that the largest size supported by a 32-bit BAR is 2GB.)
I will drop this patch in V4.
Kind regards,
Niklas
>
> - Mani
>
> > Thus, we need to check the flag also after pci_epf_alloc_space().
> >
> > Signed-off-by: Niklas Cassel <cassel@xxxxxxxxxx>
> > ---
> > drivers/pci/endpoint/functions/pci-epf-test.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> > index cd4ffb39dcdc..01ba088849cc 100644
> > --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> > +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> > @@ -865,6 +865,12 @@ static int pci_epf_test_alloc_space(struct pci_epf *epf)
> > dev_err(dev, "Failed to allocate space for BAR%d\n",
> > bar);
> > epf_test->reg[bar] = base;
> > +
> > + /*
> > + * pci_epf_alloc_space() might have given us a 64-bit BAR,
> > + * if we requested a size larger than 4 GB.
> > + */
> > + add = (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ? 2 : 1;
> > }
> >
> > return 0;
> > --
> > 2.44.0
> >
>
> --
> மணிவண்ணன் சதாசிவம்
