| Message ID | 20240416043225.1462548-1-kai.heng.feng@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | [v8,1/3] PCI: Add helper to check if any of ancestor device support D3cold | expand |
On 4/15/24 9:32 PM, Kai-Heng Feng wrote: > In addition to nearest upstream bridge, driver may want to know if the > entire hierarchy can be powered off to perform different action. > > So walk higher up the hierarchy to find out if any device has valid > _PR3. > > The user will be introduced in next patch. > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> > --- Since it has been a while, I was not sure what this series is about. IMO, it is better to include a cover letter with the summary of your changes. > v8: > - No change. > > drivers/pci/pci.c | 16 ++++++++++++++++ > include/linux/pci.h | 2 ++ > 2 files changed, 18 insertions(+) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index e5f243dd4288..7a5662f116b8 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -6225,6 +6225,22 @@ bool pci_pr3_present(struct pci_dev *pdev) > acpi_has_method(adev->handle, "_PR3"); > } > EXPORT_SYMBOL_GPL(pci_pr3_present); > + > +bool pci_ancestor_pr3_present(struct pci_dev *pdev) > +{ > + struct pci_dev *parent = pdev; > + > + if (acpi_disabled) > + return false; > + > + while ((parent = pci_upstream_bridge(parent))) { > + if (pci_pr3_present(pdev)) I think it should be "parent" here? > + return true; > + } > + > + return false; > +} > +EXPORT_SYMBOL_GPL(pci_ancestor_pr3_present); > #endif > > /** > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 16493426a04f..cd71ebfd0f89 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -2620,10 +2620,12 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus); > void > pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *)); > bool pci_pr3_present(struct pci_dev *pdev); > +bool pci_ancestor_pr3_present(struct pci_dev *pdev); > #else > static inline struct irq_domain * > pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; } > static inline bool pci_pr3_present(struct pci_dev *pdev) { return false; } > +static inline bool pci_ancestor_pr3_present(struct pci_dev *pdev) { return false; } > #endif > > #ifdef CONFIG_EEH
On Thu, Apr 18, 2024 at 9:15 AM Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> wrote: > > > On 4/15/24 9:32 PM, Kai-Heng Feng wrote: > > In addition to nearest upstream bridge, driver may want to know if the > > entire hierarchy can be powered off to perform different action. > > > > So walk higher up the hierarchy to find out if any device has valid > > _PR3. > > > > The user will be introduced in next patch. > > > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> > > --- > > Since it has been a while, I was not sure what this series is about. > > IMO, it is better to include a cover letter with the summary of your > changes. OK, will do in next revision. > > > > v8: > > - No change. > > > > drivers/pci/pci.c | 16 ++++++++++++++++ > > include/linux/pci.h | 2 ++ > > 2 files changed, 18 insertions(+) > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index e5f243dd4288..7a5662f116b8 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > > @@ -6225,6 +6225,22 @@ bool pci_pr3_present(struct pci_dev *pdev) > > acpi_has_method(adev->handle, "_PR3"); > > } > > EXPORT_SYMBOL_GPL(pci_pr3_present); > > + > > +bool pci_ancestor_pr3_present(struct pci_dev *pdev) > > +{ > > + struct pci_dev *parent = pdev; > > + > > + if (acpi_disabled) > > + return false; > > + > > + while ((parent = pci_upstream_bridge(parent))) { > > + if (pci_pr3_present(pdev)) > > I think it should be "parent" here? Thanks for catching this. But this patch will be dropped in next version for better simplicity. Kai-Heng > > > + return true; > > + } > > + > > + return false; > > +} > > +EXPORT_SYMBOL_GPL(pci_ancestor_pr3_present); > > #endif > > > > /** > > diff --git a/include/linux/pci.h b/include/linux/pci.h > > index 16493426a04f..cd71ebfd0f89 100644 > > --- a/include/linux/pci.h > > +++ b/include/linux/pci.h > > @@ -2620,10 +2620,12 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus); > > void > > pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *)); > > bool pci_pr3_present(struct pci_dev *pdev); > > +bool pci_ancestor_pr3_present(struct pci_dev *pdev); > > #else > > static inline struct irq_domain * > > pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; } > > static inline bool pci_pr3_present(struct pci_dev *pdev) { return false; } > > +static inline bool pci_ancestor_pr3_present(struct pci_dev *pdev) { return false; } > > #endif > > > > #ifdef CONFIG_EEH > > -- > Sathyanarayanan Kuppuswamy > Linux Kernel Developer >
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e5f243dd4288..7a5662f116b8 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6225,6 +6225,22 @@ bool pci_pr3_present(struct pci_dev *pdev) acpi_has_method(adev->handle, "_PR3"); } EXPORT_SYMBOL_GPL(pci_pr3_present); + +bool pci_ancestor_pr3_present(struct pci_dev *pdev) +{ + struct pci_dev *parent = pdev; + + if (acpi_disabled) + return false; + + while ((parent = pci_upstream_bridge(parent))) { + if (pci_pr3_present(pdev)) + return true; + } + + return false; +} +EXPORT_SYMBOL_GPL(pci_ancestor_pr3_present); #endif /** diff --git a/include/linux/pci.h b/include/linux/pci.h index 16493426a04f..cd71ebfd0f89 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -2620,10 +2620,12 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus); void pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *)); bool pci_pr3_present(struct pci_dev *pdev); +bool pci_ancestor_pr3_present(struct pci_dev *pdev); #else static inline struct irq_domain * pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; } static inline bool pci_pr3_present(struct pci_dev *pdev) { return false; } +static inline bool pci_ancestor_pr3_present(struct pci_dev *pdev) { return false; } #endif #ifdef CONFIG_EEH
In addition to nearest upstream bridge, driver may want to know if the entire hierarchy can be powered off to perform different action. So walk higher up the hierarchy to find out if any device has valid _PR3. The user will be introduced in next patch. Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> --- v8: - No change. drivers/pci/pci.c | 16 ++++++++++++++++ include/linux/pci.h | 2 ++ 2 files changed, 18 insertions(+)