[v2] PCI: Simplify bus range parsing

[PATCH v2 3/4] PCI: of: Simplify devm_of_pci_get_host_bridge_resources() interface

Posted by Bjorn Helgaas 11 months, 1 week ago

From: Bjorn Helgaas <bhelgaas@google.com>

Previously pci_parse_request_of_pci_ranges() supplied the default bus range
to devm_of_pci_get_host_bridge_resources(), but that function is static and
has no other callers, so there's no reason to complicate its interface by
passing the default bus range.

Drop the busno and bus_max parameters and use 0x0 and 0xff directly in
devm_of_pci_get_host_bridge_resources().

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/pci/of.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 48b9274b846e..a2acfc52caf4 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -302,8 +302,6 @@ EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
  * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
  *                                           host bridge resources from DT
  * @dev: host bridge device
- * @busno: bus number associated with the bridge root bus
- * @bus_max: maximum number of buses for this bridge
  * @resources: list where the range of resources will be added after DT parsing
  * @ib_resources: list where the range of inbound resources (with addresses
  *                from 'dma-ranges') will be added after DT parsing
@@ -319,7 +317,6 @@ EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
  * value if it failed.
  */
 static int devm_of_pci_get_host_bridge_resources(struct device *dev,
-			unsigned char busno, unsigned char bus_max,
 			struct list_head *resources,
 			struct list_head *ib_resources,
 			resource_size_t *io_base)
@@ -343,12 +340,15 @@ static int devm_of_pci_get_host_bridge_resources(struct device *dev,
 
 	err = of_pci_parse_bus_range(dev_node, bus_range);
 	if (err) {
-		bus_range->start = busno;
-		bus_range->end = bus_max;
+		bus_range->start = 0;
+		bus_range->end = 0xff;
 		bus_range->flags = IORESOURCE_BUS;
 	} else {
-		if (bus_range->end > bus_range->start + bus_max)
-			bus_range->end = bus_range->start + bus_max;
+		if (bus_range->end > 0xff) {
+			dev_info(dev, "  Invalid end bus number in %pR, defaulting to 0xff\n",
+				 bus_range);
+			bus_range->end = 0xff;
+		}
 	}
 	pci_add_resource(resources, bus_range);
 
@@ -595,7 +595,7 @@ static int pci_parse_request_of_pci_ranges(struct device *dev,
 	INIT_LIST_HEAD(&bridge->windows);
 	INIT_LIST_HEAD(&bridge->dma_ranges);
 
-	err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, &bridge->windows,
+	err = devm_of_pci_get_host_bridge_resources(dev, &bridge->windows,
 						    &bridge->dma_ranges, &iobase);
 	if (err)
 		return err;
-- 
2.34.1

Re: [PATCH v2 3/4] PCI: of: Simplify devm_of_pci_get_host_bridge_resources() interface

Posted by Sathyanarayanan Kuppuswamy 11 months, 1 week ago

Hi Bjorn,

On 1/13/25 3:15 PM, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <bhelgaas@google.com>
>
> Previously pci_parse_request_of_pci_ranges() supplied the default bus range
> to devm_of_pci_get_host_bridge_resources(), but that function is static and
> has no other callers, so there's no reason to complicate its interface by
> passing the default bus range.
>
> Drop the busno and bus_max parameters and use 0x0 and 0xff directly in
> devm_of_pci_get_host_bridge_resources().
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> ---
>   drivers/pci/of.c | 16 ++++++++--------
>   1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index 48b9274b846e..a2acfc52caf4 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -302,8 +302,6 @@ EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
>    * devm_of_pci_get_host_bridge_resources() - Resource-managed parsing of PCI
>    *                                           host bridge resources from DT
>    * @dev: host bridge device
> - * @busno: bus number associated with the bridge root bus
> - * @bus_max: maximum number of buses for this bridge
>    * @resources: list where the range of resources will be added after DT parsing
>    * @ib_resources: list where the range of inbound resources (with addresses
>    *                from 'dma-ranges') will be added after DT parsing
> @@ -319,7 +317,6 @@ EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
>    * value if it failed.
>    */
>   static int devm_of_pci_get_host_bridge_resources(struct device *dev,
> -			unsigned char busno, unsigned char bus_max,
>   			struct list_head *resources,
>   			struct list_head *ib_resources,
>   			resource_size_t *io_base)
> @@ -343,12 +340,15 @@ static int devm_of_pci_get_host_bridge_resources(struct device *dev,
>   
>   	err = of_pci_parse_bus_range(dev_node, bus_range);
>   	if (err) {
> -		bus_range->start = busno;
> -		bus_range->end = bus_max;
> +		bus_range->start = 0;
> +		bus_range->end = 0xff;
>   		bus_range->flags = IORESOURCE_BUS;
>   	} else {
> -		if (bus_range->end > bus_range->start + bus_max)
> -			bus_range->end = bus_range->start + bus_max;
> +		if (bus_range->end > 0xff) {
> +			dev_info(dev, "  Invalid end bus number in %pR, defaulting to 0xff\n",
> +				 bus_range);

Use dev_warn() ? I noticed that dev_info() is used in place of 
warning/errors in this file.
Probably it needs to be cleaned?

> +			bus_range->end = 0xff;
> +		}
>   	}
>   	pci_add_resource(resources, bus_range);
>   
> @@ -595,7 +595,7 @@ static int pci_parse_request_of_pci_ranges(struct device *dev,
>   	INIT_LIST_HEAD(&bridge->windows);
>   	INIT_LIST_HEAD(&bridge->dma_ranges);
>   
> -	err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, &bridge->windows,
> +	err = devm_of_pci_get_host_bridge_resources(dev, &bridge->windows,
>   						    &bridge->dma_ranges, &iobase);
>   	if (err)
>   		return err;

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer

Re: [PATCH v2 3/4] PCI: of: Simplify devm_of_pci_get_host_bridge_resources() interface

Posted by Bjorn Helgaas 11 months ago

On Tue, Jan 14, 2025 at 04:21:15PM -0800, Sathyanarayanan Kuppuswamy wrote:
> On 1/13/25 3:15 PM, Bjorn Helgaas wrote:
> > From: Bjorn Helgaas <bhelgaas@google.com>
> > 
> > Previously pci_parse_request_of_pci_ranges() supplied the default bus range
> > to devm_of_pci_get_host_bridge_resources(), but that function is static and
> > has no other callers, so there's no reason to complicate its interface by
> > passing the default bus range.
> > 
> > Drop the busno and bus_max parameters and use 0x0 and 0xff directly in
> > devm_of_pci_get_host_bridge_resources().

> >   	} else {
> > -		if (bus_range->end > bus_range->start + bus_max)
> > -			bus_range->end = bus_range->start + bus_max;
> > +		if (bus_range->end > 0xff) {
> > +			dev_info(dev, "  Invalid end bus number in %pR, defaulting to 0xff\n",
> > +				 bus_range);
> 
> Use dev_warn() ? I noticed that dev_info() is used in place of
> warning/errors in this file.

Good point, changed.

> Probably it needs to be cleaned?
> 
> > +			bus_range->end = 0xff;