Re: [PATCH v14.c 1/4] PCI: ACPI: Add helper functions for converting ACPI <-> PCI states

[Rafael J. Wysocki]

On Fri, Aug 18, 2023 at 9:40 PM Mario Limonciello
<mario.limonciello@xxxxxxx> wrote:
>
> Several functions do internal mappings in either direction. Add
> helpers for this functionality.  No intended functional changes.
>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
> v10->v11:
>  * New patch
> ---
>  drivers/pci/pci-acpi.c | 87 +++++++++++++++++++++++++-----------------
>  1 file changed, 53 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index a05350a4e49cb..b5b65cdfa3b8b 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -884,6 +884,56 @@ acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
>         return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev);
>  }
>
> +/**
> + * map_pci_to_acpi - map a PCI power state to an ACPI D-state
> + * @state: PCI power state to map
> + *
> + * Returns: Corresponding ACPI D-state, otherwise ACPI_STATE_UNKNOWN
> + */
> +static u8 map_pci_to_acpi(pci_power_t state)

I would prefer to call this pci_power_state_to_acpi() and analogously
for the other one.

With this addressed, please feel free to add my ACK to the patch.

> +{
> +       switch (state) {
> +       case PCI_D0:
> +               return ACPI_STATE_D0;
> +       case PCI_D1:
> +               return ACPI_STATE_D1;
> +       case PCI_D2:
> +               return ACPI_STATE_D2;
> +       case PCI_D3hot:
> +               return ACPI_STATE_D3_HOT;
> +       case PCI_D3cold:
> +               return ACPI_STATE_D3_COLD;
> +       }
> +
> +       return ACPI_STATE_UNKNOWN;
> +}
> +
> +/**
> + * map_acpi_to_pci - map an ACPI D-state to a PCI power state
> + * @state: ACPI D-state to map
> + *
> + * Returns: Corresponding PCI power state, otherwise PCI_POWER_ERROR.
> + */
> +static pci_power_t map_acpi_to_pci(int state)
> +{
> +       switch (state) {
> +       case ACPI_STATE_D0:
> +               return PCI_D0;
> +       case ACPI_STATE_D1:
> +               return PCI_D1;
> +       case ACPI_STATE_D2:
> +               return PCI_D2;
> +       case ACPI_STATE_D3_HOT:
> +               return PCI_D3hot;
> +       case ACPI_STATE_D3_COLD:
> +               return PCI_D3cold;
> +       case ACPI_STATE_UNKNOWN:
> +               return PCI_UNKNOWN;
> +       }
> +
> +       return PCI_POWER_ERROR;
> +}
> +
>  /*
>   * _SxD returns the D-state with the highest power
>   * (lowest D-state number) supported in the S-state "x".
> @@ -919,19 +969,7 @@ pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
>         if (acpi_state < 0)
>                 return PCI_POWER_ERROR;
>
> -       switch (acpi_state) {
> -       case ACPI_STATE_D0:
> -               return PCI_D0;
> -       case ACPI_STATE_D1:
> -               return PCI_D1;
> -       case ACPI_STATE_D2:
> -               return PCI_D2;
> -       case ACPI_STATE_D3_HOT:
> -               return PCI_D3hot;
> -       case ACPI_STATE_D3_COLD:
> -               return PCI_D3cold;
> -       }
> -       return PCI_POWER_ERROR;
> +       return map_acpi_to_pci(acpi_state);
>  }
>
>  static struct acpi_device *acpi_pci_find_companion(struct device *dev);
> @@ -1056,13 +1094,6 @@ static void acpi_pci_config_space_access(struct pci_dev *dev, bool enable)
>  int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
>  {
>         struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
> -       static const u8 state_conv[] = {
> -               [PCI_D0] = ACPI_STATE_D0,
> -               [PCI_D1] = ACPI_STATE_D1,
> -               [PCI_D2] = ACPI_STATE_D2,
> -               [PCI_D3hot] = ACPI_STATE_D3_HOT,
> -               [PCI_D3cold] = ACPI_STATE_D3_COLD,
> -       };
>         int error;
>
>         /* If the ACPI device has _EJ0, ignore the device */
> @@ -1089,7 +1120,7 @@ int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
>                 acpi_pci_config_space_access(dev, false);
>         }
>
> -       error = acpi_device_set_power(adev, state_conv[state]);
> +       error = acpi_device_set_power(adev, map_pci_to_acpi(state));
>         if (error)
>                 return error;
>
> @@ -1111,23 +1142,11 @@ int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
>  pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
>  {
>         struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
> -       static const pci_power_t state_conv[] = {
> -               [ACPI_STATE_D0]      = PCI_D0,
> -               [ACPI_STATE_D1]      = PCI_D1,
> -               [ACPI_STATE_D2]      = PCI_D2,
> -               [ACPI_STATE_D3_HOT]  = PCI_D3hot,
> -               [ACPI_STATE_D3_COLD] = PCI_D3cold,
> -       };
> -       int state;
>
>         if (!adev || !acpi_device_power_manageable(adev))
>                 return PCI_UNKNOWN;
>
> -       state = adev->power.state;
> -       if (state == ACPI_STATE_UNKNOWN)
> -               return PCI_UNKNOWN;
> -
> -       return state_conv[state];
> +       return map_acpi_to_pci(adev->power.state);
>  }
>
>  void acpi_pci_refresh_power_state(struct pci_dev *dev)
> --
> 2.34.1
>