On Wed, Jun 05, 2024 at 10:15:59AM +0200, Philipp Stanner wrote:
> The bit describing whether the PCI device is currently enabled is stored
> in struct pci_devres. Besides this struct being subject of a cleanup
> process, struct pci_device is in general the right place to store this
> information, since it is not devres-specific.
>
> Move the 'enabled' boolean bit to struct pci_dev.
I think this (and the similar 'pinned' patch) appeared in v6.
It sounds plausible to have this in struct pci_dev, but it's confusing
to have both:
pci_dev.enabled
pci_dev.enable_cnt, used by pci_is_enabled()
I haven't looked hard enough to see whether both are required. If
they are, I think we should rename "enabled" to something descriptive
enough to make it obviously different from "enable_cnt".
> Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx>
> ---
> drivers/pci/devres.c | 11 ++++-------
> drivers/pci/pci.c | 17 ++++++++++-------
> drivers/pci/pci.h | 1 -
> include/linux/pci.h | 1 +
> 4 files changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c
> index 572a4e193879..ea590caf8995 100644
> --- a/drivers/pci/devres.c
> +++ b/drivers/pci/devres.c
> @@ -398,7 +398,7 @@ static void pcim_release(struct device *gendev, void *res)
> if (this->restore_intx)
> pci_intx(dev, this->orig_intx);
>
> - if (this->enabled && !this->pinned)
> + if (!this->pinned)
> pci_disable_device(dev);
> }
>
> @@ -441,14 +441,11 @@ int pcim_enable_device(struct pci_dev *pdev)
> dr = get_pci_dr(pdev);
> if (unlikely(!dr))
> return -ENOMEM;
> - if (dr->enabled)
> - return 0;
>
> rc = pci_enable_device(pdev);
> - if (!rc) {
> + if (!rc)
> pdev->is_managed = 1;
> - dr->enabled = 1;
> - }
> +
> return rc;
> }
> EXPORT_SYMBOL(pcim_enable_device);
> @@ -466,7 +463,7 @@ void pcim_pin_device(struct pci_dev *pdev)
> struct pci_devres *dr;
>
> dr = find_pci_dr(pdev);
> - WARN_ON(!dr || !dr->enabled);
> + WARN_ON(!dr || !pdev->enabled);
> if (dr)
> dr->pinned = 1;
> }
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 8dd711b9a291..04accdfab7ce 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2011,6 +2011,9 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
> u16 cmd;
> u8 pin;
>
> + if (dev->enabled)
> + return 0;
> +
> err = pci_set_power_state(dev, PCI_D0);
> if (err < 0 && err != -EIO)
> return err;
> @@ -2025,7 +2028,7 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
> pci_fixup_device(pci_fixup_enable, dev);
>
> if (dev->msi_enabled || dev->msix_enabled)
> - return 0;
> + goto success_out;
>
> pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
> if (pin) {
> @@ -2035,6 +2038,8 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
> cmd & ~PCI_COMMAND_INTX_DISABLE);
> }
>
> +success_out:
> + dev->enabled = true;
> return 0;
> }
>
> @@ -2193,6 +2198,9 @@ static void do_pci_disable_device(struct pci_dev *dev)
> {
> u16 pci_command;
>
> + if (!dev->enabled)
> + return;
> +
> pci_read_config_word(dev, PCI_COMMAND, &pci_command);
> if (pci_command & PCI_COMMAND_MASTER) {
> pci_command &= ~PCI_COMMAND_MASTER;
> @@ -2200,6 +2208,7 @@ static void do_pci_disable_device(struct pci_dev *dev)
> }
>
> pcibios_disable_device(dev);
> + dev->enabled = false;
> }
>
> /**
> @@ -2227,12 +2236,6 @@ void pci_disable_enabled_device(struct pci_dev *dev)
> */
> void pci_disable_device(struct pci_dev *dev)
> {
> - struct pci_devres *dr;
> -
> - dr = find_pci_dr(dev);
> - if (dr)
> - dr->enabled = 0;
> -
> dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0,
> "disabling already-disabled device");
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 9fd50bc99e6b..e223e0f7dada 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -823,7 +823,6 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
> * then remove them from here.
> */
> struct pci_devres {
> - unsigned int enabled:1;
> unsigned int pinned:1;
> unsigned int orig_intx:1;
> unsigned int restore_intx:1;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 16493426a04f..110548f00b3b 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -367,6 +367,7 @@ struct pci_dev {
> this is D0-D3, D0 being fully
> functional, and D3 being off. */
> u8 pm_cap; /* PM capability offset */
> + unsigned int enabled:1; /* Whether this dev is enabled */
> unsigned int imm_ready:1; /* Supports Immediate Readiness */
> unsigned int pme_support:5; /* Bitmask of states from which PME#
> can be generated */
> --
> 2.45.0
>
