diff mbox series

[v7,04/15] PCI: Add pci_find_vsec_capability() to find a specific VSEC

Message ID d89506834fb11c6fa0bd5d515c0dd55b13ac6958.1613674948.git.gustavo.pimentel@synopsys.com (mailing list archive)
State Not Applicable
Headers show
Series dmaengine: dw-edma: HDMA support | expand

Commit Message

Gustavo Pimentel Feb. 18, 2021, 7:03 p.m. UTC
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@synopsys.com>
---
 drivers/pci/pci.c   | 30 ++++++++++++++++++++++++++++++
 include/linux/pci.h |  1 +
 2 files changed, 31 insertions(+)

Comments

Bjorn Helgaas Feb. 18, 2021, 7:27 p.m. UTC | #1
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@synopsys.com>

Beautiful, thanks!

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
>  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.

>  u64 pci_get_dsn(struct pci_dev *dev);
>  
> -- 
> 2.7.4
>
Gustavo Pimentel Feb. 18, 2021, 9:32 p.m. UTC | #2
On Thu, Feb 18, 2021 at 19:27:30, Bjorn Helgaas <helgaas@kernel.org> 
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@synopsys.com>
> 
> Beautiful, thanks!
> 
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> 
> > ---
> >  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
> >
diff mbox series

Patch

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);
 
 u64 pci_get_dsn(struct pci_dev *dev);