| Message ID | 20240313105804.100168-2-cassel@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: endpoint: set prefetchable bit for 64-bit BARs | expand |
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. - Mani > Thus, we need to check the flag also after pci_epf_alloc_space(). > > Signed-off-by: Niklas Cassel <cassel@kernel.org> > --- > 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 >
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@kernel.org> > > --- > > 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
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;
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. Thus, we need to check the flag also after pci_epf_alloc_space(). Signed-off-by: Niklas Cassel <cassel@kernel.org> --- drivers/pci/endpoint/functions/pci-epf-test.c | 6 ++++++ 1 file changed, 6 insertions(+)