linux-kernel - Re: [PATCH 4/5] PCI/pwrctl: Move pwrctl device creation to its own helper function

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACMJSesmyfS4wj=ys16FmqpAoojuChY1OHSC750bjtM23y5baA@mail.gmail.com>
Date: Wed, 23 Oct 2024 12:23:57 +0200
From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
To: manivannan.sadhasivam@...aro.org
Cc: Bjorn Helgaas <bhelgaas@...gle.com>, linux-pci@...r.kernel.org, 
	linux-kernel@...r.kernel.org, Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, 
	Johan Hovold <johan+linaro@...nel.org>, Abel Vesa <abel.vesa@...aro.org>, 
	Stephan Gerhold <stephan.gerhold@...aro.org>, 
	Srinivas Kandagatla <srinivas.kandagatla@...aro.org>, 
	Bjorn Andersson <bjorn.andersson@....qualcomm.com>
Subject: Re: [PATCH 4/5] PCI/pwrctl: Move pwrctl device creation to its own
 helper function

On Tue, 22 Oct 2024 at 12:28, Manivannan Sadhasivam via B4 Relay
<devnull+manivannan.sadhasivam.linaro.org@...nel.org> wrote:
>
> From: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
>
> This makes the pci_bus_add_device() API easier to maintain. Also add more
> comments to the helper to describe how the devices are created.
>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
> ---
>  drivers/pci/bus.c | 59 ++++++++++++++++++++++++++++++++++++++-----------------
>  1 file changed, 41 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
> index 351af581904f..c4cae1775c9e 100644
> --- a/drivers/pci/bus.c
> +++ b/drivers/pci/bus.c
> @@ -321,6 +321,46 @@ void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
>
>  void __weak pcibios_bus_add_device(struct pci_dev *pdev) { }
>
> +/*
> + * Create pwrctl devices (if required) for the PCI devices to handle the power
> + * state.
> + */
> +static void pci_pwrctl_create_devices(struct pci_dev *dev)
> +{
> +       struct device_node *np = dev_of_node(&dev->dev);
> +       struct device *parent = &dev->dev;
> +       struct platform_device *pdev;
> +
> +       /*
> +        * First ensure that we are starting from a PCI bridge and it has a
> +        * corresponding devicetree node.
> +        */
> +       if (np && pci_is_bridge(dev)) {
> +               /*
> +                * Now look for the child PCI device nodes and create pwrctl
> +                * devices for them. The pwrctl device drivers will manage the
> +                * power state of the devices.
> +                */
> +               for_each_child_of_node_scoped(np, child) {
> +                       /*
> +                        * First check whether the pwrctl device really needs to
> +                        * be created or not. This is decided based on at least
> +                        * one of the power supplies being defined in the
> +                        * devicetree node of the device.
> +                        */
> +                       if (!of_pci_is_supply_present(child)) {
> +                               pci_dbg(dev, "skipping OF node: %s\n", child->name);
> +                               return;
> +                       }
> +
> +                       /* Now create the pwrctl device */
> +                       pdev = of_platform_device_create(child, NULL, parent);
> +                       if (!pdev)
> +                               pci_err(dev, "failed to create OF node: %s\n", child->name);
> +               }
> +       }
> +}
> +
>  /**
>   * pci_bus_add_device - start driver for a single device
>   * @dev: device to add
> @@ -345,24 +385,7 @@ void pci_bus_add_device(struct pci_dev *dev)
>         pci_proc_attach_device(dev);
>         pci_bridge_d3_update(dev);
>
> -       if (dev_of_node(&dev->dev) && pci_is_bridge(dev)) {
> -               for_each_child_of_node_scoped(dn, child) {
> -                       /*
> -                        * First check whether the pwrctl device needs to be
> -                        * created or not. This is decided based on at least
> -                        * one of the power supplies being defined in the
> -                        * devicetree node of the device.
> -                        */
> -                       if (!of_pci_is_supply_present(child)) {
> -                               pci_dbg(dev, "skipping OF node: %s\n", child->name);
> -                               continue;
> -                       }
> -
> -                       pdev = of_platform_device_create(child, NULL, &dev->dev);
> -                       if (!pdev)
> -                               pci_err(dev, "failed to create OF node: %s\n", child->name);
> -               }
> -       }
> +       pci_pwrctl_create_devices(dev);
>
>         /*
>          * Create a device link between the PCI device and pwrctl device (if
>
> --
> 2.25.1
>
>

Would it be possible to move this into drivers/pwrctl/ and provide a
header stub for when PCI_PWRCTL is disabled in Kconfig?

Bart