diff mbox series

[dt,+,pci,2/2] PCI: Add function for parsing `slot-power-limit-milliwatt` DT property

Message ID 20211031150706.27873-2-kabel@kernel.org (mailing list archive)
State Superseded
Delegated to: Rob Herring
Headers show
Series [dt,+,pci,1/2] dt-bindings: Add 'slot-power-limit-milliwatt' PCIe port property | expand

Commit Message

Marek Behún Oct. 31, 2021, 3:07 p.m. UTC
From: Pali Rohár <pali@kernel.org>

Add function of_pci_get_slot_power_limit(), which parses the
`slot-power-limit-milliwatt` DT property, returning the value in
milliwatts and in format ready for the PCIe Slot Capabilities Register.

Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
---
 drivers/pci/of.c  | 64 +++++++++++++++++++++++++++++++++++++++++++++++
 drivers/pci/pci.h | 15 +++++++++++
 2 files changed, 79 insertions(+)

Comments

Marek Behún Jan. 7, 2022, 6:04 p.m. UTC | #1
Hello Bjorn,

the property was merged into dt-schema, see
  https://github.com/devicetree-org/dt-schema/commit/7b2d7c521ba55903846cbba00518e1c4038699b4
so we don't need to add it to linux git anymore.

Since the property is documented id dt-schema, can we now merge this
patch, which adds the of_pci_get_slot_power_limit() function? Both
aardvark and mvebu driver will use this function.

Marek

On Sun, 31 Oct 2021 16:07:06 +0100
Marek Behún <kabel@kernel.org> wrote:

> From: Pali Rohár <pali@kernel.org>
> 
> Add function of_pci_get_slot_power_limit(), which parses the
> `slot-power-limit-milliwatt` DT property, returning the value in
> milliwatts and in format ready for the PCIe Slot Capabilities Register.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Signed-off-by: Marek Behún <kabel@kernel.org>
> ---
>  drivers/pci/of.c  | 64 +++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/pci/pci.h | 15 +++++++++++
>  2 files changed, 79 insertions(+)
> 
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index d84381ce82b5..9c1a38d5dd99 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -627,3 +627,67 @@ int of_pci_get_max_link_speed(struct device_node *node)
>  	return max_link_speed;
>  }
>  EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
> +
> +/**
> + * of_pci_get_slot_power_limit - Parses the "slot-power-limit-milliwatt"
> + *				 property.
> + *
> + * @node: device tree node with the slot power limit information
> + * @slot_power_limit_value: pointer where the value should be stored in PCIe
> + *			    Slot Capabilities Register format
> + * @slot_power_limit_scale: pointer where the scale should be stored in PCIe
> + *			    Slot Capabilities Register format
> + *
> + * Returns the slot power limit in milliwatts and if @slot_power_limit_value
> + * and @slot_power_limit_scale pointers are non-NULL, fills in the value and
> + * scale in format used by PCIe Slot Capabilities Register.
> + *
> + * If the property is not found or is invalid, returns 0.
> + */
> +u32 of_pci_get_slot_power_limit(struct device_node *node,
> +				u8 *slot_power_limit_value,
> +				u8 *slot_power_limit_scale)
> +{
> +	u32 slot_power_limit;
> +	u8 value, scale;
> +
> +	if (of_property_read_u32(node, "slot-power-limit-milliwatt",
> +				 &slot_power_limit))
> +		slot_power_limit = 0;
> +
> +	/* Calculate Slot Power Limit Value and Slot Power Limit Scale */
> +	if (slot_power_limit == 0) {
> +		value = 0x00;
> +		scale = 0;
> +	} else if (slot_power_limit <= 255) {
> +		value = slot_power_limit;
> +		scale = 3;
> +	} else if (slot_power_limit <= 255*10) {
> +		value = slot_power_limit / 10;
> +		scale = 2;
> +	} else if (slot_power_limit <= 255*100) {
> +		value = slot_power_limit / 100;
> +		scale = 1;
> +	} else if (slot_power_limit <= 239*1000) {
> +		value = slot_power_limit / 1000;
> +		scale = 0;
> +	} else if (slot_power_limit <= 250*1000) {
> +		value = 0xF0;
> +		scale = 0;
> +	} else if (slot_power_limit <= 275*1000) {
> +		value = 0xF1;
> +		scale = 0;
> +	} else {
> +		value = 0xF2;
> +		scale = 0;
> +	}
> +
> +	if (slot_power_limit_value)
> +		*slot_power_limit_value = value;
> +
> +	if (slot_power_limit_scale)
> +		*slot_power_limit_scale = scale;
> +
> +	return slot_power_limit;
> +}
> +EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit);
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 1cce56c2aea0..9352278141be 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -665,6 +665,9 @@ struct device_node;
>  int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
>  int of_get_pci_domain_nr(struct device_node *node);
>  int of_pci_get_max_link_speed(struct device_node *node);
> +u32 of_pci_get_slot_power_limit(struct device_node *node,
> +				u8 *slot_power_limit_value,
> +				u8 *slot_power_limit_scale);
>  void pci_set_of_node(struct pci_dev *dev);
>  void pci_release_of_node(struct pci_dev *dev);
>  void pci_set_bus_of_node(struct pci_bus *bus);
> @@ -691,6 +694,18 @@ of_pci_get_max_link_speed(struct device_node *node)
>  	return -EINVAL;
>  }
>  
> +static inline u32
> +of_pci_get_slot_power_limit(struct device_node *node,
> +			    u8 *slot_power_limit_value,
> +			    u8 *slot_power_limit_scale)
> +{
> +	if (slot_power_limit_value)
> +		*slot_power_limit_value = 0;
> +	if (slot_power_limit_scale)
> +		*slot_power_limit_scale = 0;
> +	return 0;
> +}
> +
>  static inline void pci_set_of_node(struct pci_dev *dev) { }
>  static inline void pci_release_of_node(struct pci_dev *dev) { }
>  static inline void pci_set_bus_of_node(struct pci_bus *bus) { }
Rob Herring Jan. 7, 2022, 9:17 p.m. UTC | #2
On Sun, Oct 31, 2021 at 10:07 AM Marek Behún <kabel@kernel.org> wrote:
>
> From: Pali Rohár <pali@kernel.org>
>
> Add function of_pci_get_slot_power_limit(), which parses the
> `slot-power-limit-milliwatt` DT property, returning the value in
> milliwatts and in format ready for the PCIe Slot Capabilities Register.
>
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Signed-off-by: Marek Behún <kabel@kernel.org>
> ---
>  drivers/pci/of.c  | 64 +++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/pci/pci.h | 15 +++++++++++
>  2 files changed, 79 insertions(+)

Reviewed-by: Rob Herring <robh@kernel.org>
Bjorn Helgaas Jan. 12, 2022, 10:08 p.m. UTC | #3
On Sun, Oct 31, 2021 at 04:07:06PM +0100, Marek Behún wrote:
> From: Pali Rohár <pali@kernel.org>
> 
> Add function of_pci_get_slot_power_limit(), which parses the
> `slot-power-limit-milliwatt` DT property, returning the value in
> milliwatts and in format ready for the PCIe Slot Capabilities Register.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Signed-off-by: Marek Behún <kabel@kernel.org>

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

Do we have a caller of of_pci_get_slot_power_limit() yet?  I didn't
see one from a quick look
(https://lore.kernel.org/linux-pci/?q=b%3Aof_pci_get_slot_power_limit).

Let's merge this when we have a user for it.

> ---
>  drivers/pci/of.c  | 64 +++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/pci/pci.h | 15 +++++++++++
>  2 files changed, 79 insertions(+)
> 
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index d84381ce82b5..9c1a38d5dd99 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -627,3 +627,67 @@ int of_pci_get_max_link_speed(struct device_node *node)
>  	return max_link_speed;
>  }
>  EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
> +
> +/**
> + * of_pci_get_slot_power_limit - Parses the "slot-power-limit-milliwatt"
> + *				 property.
> + *
> + * @node: device tree node with the slot power limit information
> + * @slot_power_limit_value: pointer where the value should be stored in PCIe
> + *			    Slot Capabilities Register format
> + * @slot_power_limit_scale: pointer where the scale should be stored in PCIe
> + *			    Slot Capabilities Register format
> + *
> + * Returns the slot power limit in milliwatts and if @slot_power_limit_value
> + * and @slot_power_limit_scale pointers are non-NULL, fills in the value and
> + * scale in format used by PCIe Slot Capabilities Register.
> + *
> + * If the property is not found or is invalid, returns 0.
> + */
> +u32 of_pci_get_slot_power_limit(struct device_node *node,
> +				u8 *slot_power_limit_value,
> +				u8 *slot_power_limit_scale)
> +{
> +	u32 slot_power_limit;
> +	u8 value, scale;
> +
> +	if (of_property_read_u32(node, "slot-power-limit-milliwatt",
> +				 &slot_power_limit))
> +		slot_power_limit = 0;
> +
> +	/* Calculate Slot Power Limit Value and Slot Power Limit Scale */
> +	if (slot_power_limit == 0) {
> +		value = 0x00;
> +		scale = 0;
> +	} else if (slot_power_limit <= 255) {
> +		value = slot_power_limit;
> +		scale = 3;
> +	} else if (slot_power_limit <= 255*10) {
> +		value = slot_power_limit / 10;
> +		scale = 2;
> +	} else if (slot_power_limit <= 255*100) {
> +		value = slot_power_limit / 100;
> +		scale = 1;
> +	} else if (slot_power_limit <= 239*1000) {
> +		value = slot_power_limit / 1000;
> +		scale = 0;
> +	} else if (slot_power_limit <= 250*1000) {
> +		value = 0xF0;
> +		scale = 0;
> +	} else if (slot_power_limit <= 275*1000) {
> +		value = 0xF1;
> +		scale = 0;
> +	} else {
> +		value = 0xF2;
> +		scale = 0;
> +	}
> +
> +	if (slot_power_limit_value)
> +		*slot_power_limit_value = value;
> +
> +	if (slot_power_limit_scale)
> +		*slot_power_limit_scale = scale;
> +
> +	return slot_power_limit;
> +}
> +EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit);
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 1cce56c2aea0..9352278141be 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -665,6 +665,9 @@ struct device_node;
>  int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
>  int of_get_pci_domain_nr(struct device_node *node);
>  int of_pci_get_max_link_speed(struct device_node *node);
> +u32 of_pci_get_slot_power_limit(struct device_node *node,
> +				u8 *slot_power_limit_value,
> +				u8 *slot_power_limit_scale);
>  void pci_set_of_node(struct pci_dev *dev);
>  void pci_release_of_node(struct pci_dev *dev);
>  void pci_set_bus_of_node(struct pci_bus *bus);
> @@ -691,6 +694,18 @@ of_pci_get_max_link_speed(struct device_node *node)
>  	return -EINVAL;
>  }
>  
> +static inline u32
> +of_pci_get_slot_power_limit(struct device_node *node,
> +			    u8 *slot_power_limit_value,
> +			    u8 *slot_power_limit_scale)
> +{
> +	if (slot_power_limit_value)
> +		*slot_power_limit_value = 0;
> +	if (slot_power_limit_scale)
> +		*slot_power_limit_scale = 0;
> +	return 0;
> +}
> +
>  static inline void pci_set_of_node(struct pci_dev *dev) { }
>  static inline void pci_release_of_node(struct pci_dev *dev) { }
>  static inline void pci_set_bus_of_node(struct pci_bus *bus) { }
> -- 
> 2.32.0
>
Pali Rohár Jan. 12, 2022, 10:28 p.m. UTC | #4
On Wednesday 12 January 2022 16:08:15 Bjorn Helgaas wrote:
> On Sun, Oct 31, 2021 at 04:07:06PM +0100, Marek Behún wrote:
> > From: Pali Rohár <pali@kernel.org>
> > 
> > Add function of_pci_get_slot_power_limit(), which parses the
> > `slot-power-limit-milliwatt` DT property, returning the value in
> > milliwatts and in format ready for the PCIe Slot Capabilities Register.
> > 
> > Signed-off-by: Pali Rohár <pali@kernel.org>
> > Signed-off-by: Marek Behún <kabel@kernel.org>
> 
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> 
> Do we have a caller of of_pci_get_slot_power_limit() yet?  I didn't
> see one from a quick look
> (https://lore.kernel.org/linux-pci/?q=b%3Aof_pci_get_slot_power_limit).
> 
> Let's merge this when we have a user for it.

I have a patch for both pci-mvebu.c and pci-aardvark.c drivers. But
there are lot of patches for these drivers waiting on mailing list for
review... Should I sent another patch for pci-mvebu.c which will use
this of_pci_get_slot_power_limit() function?

> > ---
> >  drivers/pci/of.c  | 64 +++++++++++++++++++++++++++++++++++++++++++++++
> >  drivers/pci/pci.h | 15 +++++++++++
> >  2 files changed, 79 insertions(+)
> > 
> > diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> > index d84381ce82b5..9c1a38d5dd99 100644
> > --- a/drivers/pci/of.c
> > +++ b/drivers/pci/of.c
> > @@ -627,3 +627,67 @@ int of_pci_get_max_link_speed(struct device_node *node)
> >  	return max_link_speed;
> >  }
> >  EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
> > +
> > +/**
> > + * of_pci_get_slot_power_limit - Parses the "slot-power-limit-milliwatt"
> > + *				 property.
> > + *
> > + * @node: device tree node with the slot power limit information
> > + * @slot_power_limit_value: pointer where the value should be stored in PCIe
> > + *			    Slot Capabilities Register format
> > + * @slot_power_limit_scale: pointer where the scale should be stored in PCIe
> > + *			    Slot Capabilities Register format
> > + *
> > + * Returns the slot power limit in milliwatts and if @slot_power_limit_value
> > + * and @slot_power_limit_scale pointers are non-NULL, fills in the value and
> > + * scale in format used by PCIe Slot Capabilities Register.
> > + *
> > + * If the property is not found or is invalid, returns 0.
> > + */
> > +u32 of_pci_get_slot_power_limit(struct device_node *node,
> > +				u8 *slot_power_limit_value,
> > +				u8 *slot_power_limit_scale)
> > +{
> > +	u32 slot_power_limit;
> > +	u8 value, scale;
> > +
> > +	if (of_property_read_u32(node, "slot-power-limit-milliwatt",
> > +				 &slot_power_limit))
> > +		slot_power_limit = 0;
> > +
> > +	/* Calculate Slot Power Limit Value and Slot Power Limit Scale */
> > +	if (slot_power_limit == 0) {
> > +		value = 0x00;
> > +		scale = 0;
> > +	} else if (slot_power_limit <= 255) {
> > +		value = slot_power_limit;
> > +		scale = 3;
> > +	} else if (slot_power_limit <= 255*10) {
> > +		value = slot_power_limit / 10;
> > +		scale = 2;
> > +	} else if (slot_power_limit <= 255*100) {
> > +		value = slot_power_limit / 100;
> > +		scale = 1;
> > +	} else if (slot_power_limit <= 239*1000) {
> > +		value = slot_power_limit / 1000;
> > +		scale = 0;
> > +	} else if (slot_power_limit <= 250*1000) {
> > +		value = 0xF0;
> > +		scale = 0;
> > +	} else if (slot_power_limit <= 275*1000) {
> > +		value = 0xF1;
> > +		scale = 0;
> > +	} else {
> > +		value = 0xF2;
> > +		scale = 0;
> > +	}
> > +
> > +	if (slot_power_limit_value)
> > +		*slot_power_limit_value = value;
> > +
> > +	if (slot_power_limit_scale)
> > +		*slot_power_limit_scale = scale;
> > +
> > +	return slot_power_limit;
> > +}
> > +EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit);
> > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> > index 1cce56c2aea0..9352278141be 100644
> > --- a/drivers/pci/pci.h
> > +++ b/drivers/pci/pci.h
> > @@ -665,6 +665,9 @@ struct device_node;
> >  int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
> >  int of_get_pci_domain_nr(struct device_node *node);
> >  int of_pci_get_max_link_speed(struct device_node *node);
> > +u32 of_pci_get_slot_power_limit(struct device_node *node,
> > +				u8 *slot_power_limit_value,
> > +				u8 *slot_power_limit_scale);
> >  void pci_set_of_node(struct pci_dev *dev);
> >  void pci_release_of_node(struct pci_dev *dev);
> >  void pci_set_bus_of_node(struct pci_bus *bus);
> > @@ -691,6 +694,18 @@ of_pci_get_max_link_speed(struct device_node *node)
> >  	return -EINVAL;
> >  }
> >  
> > +static inline u32
> > +of_pci_get_slot_power_limit(struct device_node *node,
> > +			    u8 *slot_power_limit_value,
> > +			    u8 *slot_power_limit_scale)
> > +{
> > +	if (slot_power_limit_value)
> > +		*slot_power_limit_value = 0;
> > +	if (slot_power_limit_scale)
> > +		*slot_power_limit_scale = 0;
> > +	return 0;
> > +}
> > +
> >  static inline void pci_set_of_node(struct pci_dev *dev) { }
> >  static inline void pci_release_of_node(struct pci_dev *dev) { }
> >  static inline void pci_set_bus_of_node(struct pci_bus *bus) { }
> > -- 
> > 2.32.0
> >
Bjorn Helgaas Jan. 13, 2022, midnight UTC | #5
On Wed, Jan 12, 2022 at 11:28:22PM +0100, Pali Rohár wrote:
> On Wednesday 12 January 2022 16:08:15 Bjorn Helgaas wrote:
> > On Sun, Oct 31, 2021 at 04:07:06PM +0100, Marek Behún wrote:
> > > From: Pali Rohár <pali@kernel.org>
> > > 
> > > Add function of_pci_get_slot_power_limit(), which parses the
> > > `slot-power-limit-milliwatt` DT property, returning the value in
> > > milliwatts and in format ready for the PCIe Slot Capabilities Register.
> > > 
> > > Signed-off-by: Pali Rohár <pali@kernel.org>
> > > Signed-off-by: Marek Behún <kabel@kernel.org>
> > 
> > Acked-by: Bjorn Helgaas <bhelgaas@google.com>
> > 
> > Do we have a caller of of_pci_get_slot_power_limit() yet?  I didn't
> > see one from a quick look
> > (https://lore.kernel.org/linux-pci/?q=b%3Aof_pci_get_slot_power_limit).
> > 
> > Let's merge this when we have a user for it.
> 
> I have a patch for both pci-mvebu.c and pci-aardvark.c drivers. But
> there are lot of patches for these drivers waiting on mailing list for
> review... Should I sent another patch for pci-mvebu.c which will use
> this of_pci_get_slot_power_limit() function?

If the of_pci_get_slot_power_limit() patches are independent of the
ones waiting for review, they could be added to *this* series.

Bjorn
diff mbox series

Patch

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index d84381ce82b5..9c1a38d5dd99 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -627,3 +627,67 @@  int of_pci_get_max_link_speed(struct device_node *node)
 	return max_link_speed;
 }
 EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
+
+/**
+ * of_pci_get_slot_power_limit - Parses the "slot-power-limit-milliwatt"
+ *				 property.
+ *
+ * @node: device tree node with the slot power limit information
+ * @slot_power_limit_value: pointer where the value should be stored in PCIe
+ *			    Slot Capabilities Register format
+ * @slot_power_limit_scale: pointer where the scale should be stored in PCIe
+ *			    Slot Capabilities Register format
+ *
+ * Returns the slot power limit in milliwatts and if @slot_power_limit_value
+ * and @slot_power_limit_scale pointers are non-NULL, fills in the value and
+ * scale in format used by PCIe Slot Capabilities Register.
+ *
+ * If the property is not found or is invalid, returns 0.
+ */
+u32 of_pci_get_slot_power_limit(struct device_node *node,
+				u8 *slot_power_limit_value,
+				u8 *slot_power_limit_scale)
+{
+	u32 slot_power_limit;
+	u8 value, scale;
+
+	if (of_property_read_u32(node, "slot-power-limit-milliwatt",
+				 &slot_power_limit))
+		slot_power_limit = 0;
+
+	/* Calculate Slot Power Limit Value and Slot Power Limit Scale */
+	if (slot_power_limit == 0) {
+		value = 0x00;
+		scale = 0;
+	} else if (slot_power_limit <= 255) {
+		value = slot_power_limit;
+		scale = 3;
+	} else if (slot_power_limit <= 255*10) {
+		value = slot_power_limit / 10;
+		scale = 2;
+	} else if (slot_power_limit <= 255*100) {
+		value = slot_power_limit / 100;
+		scale = 1;
+	} else if (slot_power_limit <= 239*1000) {
+		value = slot_power_limit / 1000;
+		scale = 0;
+	} else if (slot_power_limit <= 250*1000) {
+		value = 0xF0;
+		scale = 0;
+	} else if (slot_power_limit <= 275*1000) {
+		value = 0xF1;
+		scale = 0;
+	} else {
+		value = 0xF2;
+		scale = 0;
+	}
+
+	if (slot_power_limit_value)
+		*slot_power_limit_value = value;
+
+	if (slot_power_limit_scale)
+		*slot_power_limit_scale = scale;
+
+	return slot_power_limit;
+}
+EXPORT_SYMBOL_GPL(of_pci_get_slot_power_limit);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 1cce56c2aea0..9352278141be 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -665,6 +665,9 @@  struct device_node;
 int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
 int of_get_pci_domain_nr(struct device_node *node);
 int of_pci_get_max_link_speed(struct device_node *node);
+u32 of_pci_get_slot_power_limit(struct device_node *node,
+				u8 *slot_power_limit_value,
+				u8 *slot_power_limit_scale);
 void pci_set_of_node(struct pci_dev *dev);
 void pci_release_of_node(struct pci_dev *dev);
 void pci_set_bus_of_node(struct pci_bus *bus);
@@ -691,6 +694,18 @@  of_pci_get_max_link_speed(struct device_node *node)
 	return -EINVAL;
 }
 
+static inline u32
+of_pci_get_slot_power_limit(struct device_node *node,
+			    u8 *slot_power_limit_value,
+			    u8 *slot_power_limit_scale)
+{
+	if (slot_power_limit_value)
+		*slot_power_limit_value = 0;
+	if (slot_power_limit_scale)
+		*slot_power_limit_scale = 0;
+	return 0;
+}
+
 static inline void pci_set_of_node(struct pci_dev *dev) { }
 static inline void pci_release_of_node(struct pci_dev *dev) { }
 static inline void pci_set_bus_of_node(struct pci_bus *bus) { }