On Thu, Feb 18, 2021 at 19:27:30, Bjorn Helgaas <helgaas@xxxxxxxxxx>
wrote:
> On Thu, Feb 18, 2021 at 08:03:58PM +0100, Gustavo Pimentel wrote:
> > Add pci_find_vsec_capability() to locate a Vendor-Specific Extended
> > Capability with the specified VSEC ID.
> >
> > The Vendor-Specific Extended Capability (VSEC) allows one or more
> > proprietary capabilities defined by the vendor which aren't standard
> > or shared between vendors.
> >
> > Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
>
> Beautiful, thanks!
>
> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
> > ---
> > drivers/pci/pci.c | 30 ++++++++++++++++++++++++++++++
> > include/linux/pci.h | 1 +
> > 2 files changed, 31 insertions(+)
> >
> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > index b9fecc2..aef217c 100644
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -693,6 +693,36 @@ u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap)
> > EXPORT_SYMBOL_GPL(pci_find_ht_capability);
> >
> > /**
> > + * pci_find_vsec_capability - Find a vendor-specific extended capability
> > + * @dev: PCI device to query
> > + * @vendor: Vendor ID for which capability is defined
> > + * @cap: Vendor-specific capability ID
> > + *
> > + * If @dev has Vendor ID @vendor, search for a VSEC capability with
> > + * VSEC ID @cap. If found, return the capability offset in
> > + * config space; otherwise return 0.
> > + */
> > +u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap)
> > +{
> > + u16 vsec = 0;
> > + u32 header;
> > +
> > + if (vendor != dev->vendor)
> > + return 0;
> > +
> > + while ((vsec = pci_find_next_ext_capability(dev, vsec,
> > + PCI_EXT_CAP_ID_VNDR))) {
> > + if (pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER,
> > + &header) == PCIBIOS_SUCCESSFUL &&
> > + PCI_VNDR_HEADER_ID(header) == cap)
> > + return vsec;
> > + }
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
> > +
> > +/**
> > * pci_find_parent_resource - return resource region of parent bus of given
> > * region
> > * @dev: PCI device structure contains resources to be searched
> > diff --git a/include/linux/pci.h b/include/linux/pci.h
> > index b32126d..814f814 100644
> > --- a/include/linux/pci.h
> > +++ b/include/linux/pci.h
> > @@ -1077,6 +1077,7 @@ u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap);
> > u16 pci_find_ext_capability(struct pci_dev *dev, int cap);
> > u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 pos, int cap);
> > struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
> > +u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap);
>
> If you do any updates for other reasons, slide this up one more line
> so we have:
>
> u16 pci_find_ext_capability(struct pci_dev *dev, int cap);
> u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 pos, int cap);
> u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap);
>
> struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
>
> I don't know why pci_find_next_bus() got stuck with the capability
> things. It doesn't have anything to do with finding capabilities. It
> goes more with pci_get_device(), etc.
>
> But don't roll the series just for that.
Thanks, Bjorn.
I can those arrangements if some request comes along.
I can also move the pci_find_next_bus() next to the pci_get_device() if
you like.
-Gustavo
>
> > u64 pci_get_dsn(struct pci_dev *dev);
> >
> > --
> > 2.7.4
> >
