Re: [RFC PATCH v10 6/7] PCI / PM: Move acpi wakeup code to pci core

From: Brian Norris
Date: Fri Oct 27 2017 - 19:48:46 EST

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In reply to: Jeffy Chen: "[RFC PATCH v10 6/7] PCI / PM: Move acpi wakeup code to pci core"
Next in thread: Jeffy Chen: "[RFC PATCH v10 7/7] PCI / PM: Add support for the PCIe WAKE# signal for OF"
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Hi Jeffy,

On Fri, Oct 27, 2017 at 03:26:11PM +0800, Jeffy Chen wrote:
> Move acpi wakeup code to pci core as pci_set_wakeup(), so that other
> platforms could reuse it.

I think you need to double check your refactoring. I believe you may
have changed some behavior here.

> Also add .setup_dev() / .setup_host_bridge() / .cleanup() platform pm
> ops's callbacks to setup and cleanup pci devices and host bridge for
> wakeup.
>
> Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
> ---
>
> Changes in v10: None
> Changes in v9: None
> Changes in v8: None
> Changes in v7: None
> Changes in v6: None
> Changes in v5: None
> Changes in v3: None
> Changes in v2: None
>
> drivers/pci/pci-acpi.c | 121 +++++++++++++++++++++++------------------------
> drivers/pci/pci-driver.c | 9 ++++
> drivers/pci/pci.c | 84 ++++++++++++++++++++++++++++----
> drivers/pci/pci.h | 28 +++++++++--
> drivers/pci/probe.c | 12 ++++-
> drivers/pci/remove.c | 2 +
> include/linux/pci.h | 2 +
> 7 files changed, 180 insertions(+), 78 deletions(-)
>
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index 4708eb9df71b..ee96e7afe1ac 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -569,31 +569,6 @@ static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
> return state_conv[state];
> }
>
> -static int acpi_pci_propagate_wakeup(struct pci_bus *bus, bool enable)
> -{
> - while (bus->parent) {
> - if (acpi_pm_device_can_wakeup(&bus->self->dev))
> - return acpi_pm_set_bridge_wakeup(&bus->self->dev, enable);
> -
> - bus = bus->parent;
> - }
> -
> - /* We have reached the root bus. */
> - if (bus->bridge) {
> - if (acpi_pm_device_can_wakeup(bus->bridge))
> - return acpi_pm_set_bridge_wakeup(bus->bridge, enable);
> - }
> - return 0;
> -}
> -
> -static int acpi_pci_wakeup(struct pci_dev *dev, bool enable)
> -{
> - if (acpi_pm_device_can_wakeup(&dev->dev))
> - return acpi_pm_set_device_wakeup(&dev->dev, enable);
> -
> - return acpi_pci_propagate_wakeup(dev->bus, enable);
> -}
> -
> static bool acpi_pci_need_resume(struct pci_dev *dev)
> {
> struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
> @@ -610,14 +585,29 @@ static bool acpi_pci_need_resume(struct pci_dev *dev)
> return !!adev->power.flags.dsw_present;
> }
>
> -static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
> - .is_manageable = acpi_pci_power_manageable,
> - .set_state = acpi_pci_set_power_state,
> - .get_state = acpi_pci_get_power_state,
> - .choose_state = acpi_pci_choose_state,
> - .set_wakeup = acpi_pci_wakeup,
> - .need_resume = acpi_pci_need_resume,
> -};
> +static bool acpi_pci_can_wakeup(void *pmdata)
> +{
> + struct device *dev = pmdata;
> +
> + if (!dev)
> + return false;
> +
> + return acpi_pm_device_can_wakeup(dev);
> +}
> +
> +static int acpi_pci_dev_wakeup(void *pmdata, bool enable)
> +{
> + struct device *dev = pmdata;
> +
> + return acpi_pm_set_device_wakeup(dev, enable);
> +}
> +
> +static int acpi_pci_bridge_wakeup(void *pmdata, bool enable)
> +{
> + struct device *dev = pmdata;
> +
> + return acpi_pm_set_bridge_wakeup(dev, enable);
> +}
>
> void acpi_pci_add_bus(struct pci_bus *bus)
> {
> @@ -658,20 +648,6 @@ void acpi_pci_remove_bus(struct pci_bus *bus)
> acpi_pci_slot_remove(bus);
> }
>
> -/* ACPI bus type */
> -static struct acpi_device *acpi_pci_find_companion(struct device *dev)
> -{
> - struct pci_dev *pci_dev = to_pci_dev(dev);
> - bool check_children;
> - u64 addr;
> -
> - check_children = pci_is_bridge(pci_dev);
> - /* Please ref to ACPI spec for the syntax of _ADR */
> - addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
> - return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
> - check_children);
> -}
> -
> /**
> * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
> * @pdev: the PCI device whose delay is to be updated
> @@ -723,34 +699,55 @@ static void pci_acpi_optimize_delay(struct pci_dev *pdev,
> ACPI_FREE(obj);
> }
>
> -static void pci_acpi_setup(struct device *dev)
> +static void *acpi_pci_setup_dev(struct pci_dev *pci_dev)
> {
> - struct pci_dev *pci_dev = to_pci_dev(dev);
> - struct acpi_device *adev = ACPI_COMPANION(dev);
> + struct acpi_device *adev = ACPI_COMPANION(&pci_dev->dev);
>
> if (!adev)
> - return;
> + return NULL;
>
> pci_acpi_optimize_delay(pci_dev, adev->handle);
>
> pci_acpi_add_pm_notifier(adev, pci_dev);
> if (!adev->wakeup.flags.valid)
> - return;
> + return NULL;
> +
> + device_set_wakeup_capable(&pci_dev->dev, true);
> + acpi_pm_set_device_wakeup(&pci_dev->dev, false);
>
> - device_set_wakeup_capable(dev, true);
> - acpi_pci_wakeup(pci_dev, false);
> + return &pci_dev->dev;
> }
>
> -static void pci_acpi_cleanup(struct device *dev)
> +static void *acpi_pci_setup_host_bridge(struct pci_host_bridge *bridge)
> {
> - struct acpi_device *adev = ACPI_COMPANION(dev);
> + return &bridge->dev;
> +}
>
> - if (!adev)
> - return;
> +static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
> + .is_manageable = acpi_pci_power_manageable,
> + .set_state = acpi_pci_set_power_state,
> + .get_state = acpi_pci_get_power_state,
> + .choose_state = acpi_pci_choose_state,
> + .need_resume = acpi_pci_need_resume,
> + .setup_dev = acpi_pci_setup_dev,
> + .setup_host_bridge = acpi_pci_setup_host_bridge,
> + .can_wakeup = acpi_pci_can_wakeup,
> + .dev_wakeup = acpi_pci_dev_wakeup,
> + .bridge_wakeup = acpi_pci_bridge_wakeup,
> +};
> +
> +/* ACPI bus type */
> +static struct acpi_device *acpi_pci_find_companion(struct device *dev)
> +{
> + struct pci_dev *pci_dev = to_pci_dev(dev);
> + bool check_children;
> + u64 addr;
>
> - pci_acpi_remove_pm_notifier(adev);
> - if (adev->wakeup.flags.valid)
> - device_set_wakeup_capable(dev, false);
> + check_children = pci_is_bridge(pci_dev);
> + /* Please ref to ACPI spec for the syntax of _ADR */
> + addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
> + return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
> + check_children);
> }
>
> static bool pci_acpi_bus_match(struct device *dev)
> @@ -762,8 +759,6 @@ static struct acpi_bus_type acpi_pci_bus = {
> .name = "PCI",
> .match = pci_acpi_bus_match,
> .find_companion = acpi_pci_find_companion,
> - .setup = pci_acpi_setup,
> - .cleanup = pci_acpi_cleanup,
> };
>
>
> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
> index 9be563067c0c..abb7caa8a6e5 100644
> --- a/drivers/pci/pci-driver.c
> +++ b/drivers/pci/pci-driver.c
> @@ -421,10 +421,17 @@ static int pci_device_probe(struct device *dev)
> if (error < 0)
> return error;
>
> + pci_dev->pmdata = platform_pci_setup_dev(pci_dev);
> + if (IS_ERR(pci_dev->pmdata)) {
> + pcibios_free_irq(pci_dev);
> + return PTR_ERR(pci_dev->pmdata);
> + }
> +
> pci_dev_get(pci_dev);
> if (pci_device_can_probe(pci_dev)) {
> error = __pci_device_probe(drv, pci_dev);
> if (error) {
> + platform_pci_cleanup(pci_dev->pmdata);
> pcibios_free_irq(pci_dev);
> pci_dev_put(pci_dev);
> }
> @@ -438,6 +445,8 @@ static int pci_device_remove(struct device *dev)
> struct pci_dev *pci_dev = to_pci_dev(dev);
> struct pci_driver *drv = pci_dev->driver;
>
> + platform_pci_cleanup(pci_dev->pmdata);
> +
> if (drv) {
> if (drv->remove) {
> pm_runtime_get_sync(dev);
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index e120b00a9017..6add5d3209bf 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -585,6 +585,52 @@ static inline bool platform_pci_power_manageable(struct pci_dev *dev)
> return false;
> }
>
> +void *platform_pci_setup_dev(struct pci_dev *dev)
> +{
> + if (pci_platform_pm && pci_platform_pm->setup_dev)
> + return pci_platform_pm->setup_dev(dev);
> +
> + return NULL;
> +}
> +
> +void *platform_pci_setup_host_bridge(struct pci_host_bridge *bridge)
> +{
> + if (pci_platform_pm && pci_platform_pm->setup_host_bridge)
> + return pci_platform_pm->setup_host_bridge(bridge);
> +
> + return NULL;
> +}
> +
> +void platform_pci_cleanup(void *pmdata)
> +{
> + if (pci_platform_pm && pci_platform_pm->cleanup)
> + pci_platform_pm->cleanup(pmdata);
> +}
> +
> +static inline bool platform_pci_can_wakeup(void *pmdata)
> +{
> + if (pci_platform_pm && pci_platform_pm->can_wakeup)
> + return pci_platform_pm->can_wakeup(pmdata);
> +
> + return false;
> +}
> +
> +static inline int platform_pci_dev_wakeup(void *pmdata, bool enable)
> +{
> + if (pci_platform_pm && pci_platform_pm->dev_wakeup)
> + return pci_platform_pm->dev_wakeup(pmdata, enable);
> +
> + return -ENODEV;
> +}
> +
> +static inline int platform_pci_bridge_wakeup(void *pmdata, bool enable)
> +{
> + if (pci_platform_pm && pci_platform_pm->bridge_wakeup)
> + return pci_platform_pm->bridge_wakeup(pmdata, enable);
> +
> + return -ENODEV;
> +}
> +
> static inline int platform_pci_set_power_state(struct pci_dev *dev,
> pci_power_t t)
> {
> @@ -610,14 +656,6 @@ static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev)
> return PCI_POWER_ERROR;
> }
>
> -static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable)
> -{
> - if (pci_platform_pm && pci_platform_pm->set_wakeup)
> - return pci_platform_pm->set_wakeup(dev, enable);
> -
> - return -ENODEV;

So this function used to return -ENODEV if the platform didn't implement
PM. Now you're transitioning to pci_set_wakeup() below:

> -}
> -
> static inline bool platform_pci_need_resume(struct pci_dev *dev)
> {
> if (pci_platform_pm && pci_platform_pm->need_resume)
> @@ -1903,6 +1941,32 @@ void pci_pme_active(struct pci_dev *dev, bool enable)
> }
> EXPORT_SYMBOL(pci_pme_active);
>
> +static int pci_set_wakeup(struct pci_dev *dev, bool enable)
> +{
> + struct pci_bus *bus = dev->bus;
> + struct pci_host_bridge *bridge;
> +
> + /* Handle per device wakeup */
> + if (platform_pci_can_wakeup(dev->pmdata))
> + return platform_pci_dev_wakeup(dev->pmdata, enable);
> +
> + /* Find a parent which can handle wakeup */
> + while (bus->parent) {
> + if (platform_pci_can_wakeup(bus->self->pmdata))
> + return platform_pci_bridge_wakeup(bus->self->pmdata,
> + enable);
> +
> + bus = bus->parent;
> + }
> +
> + /* We have reached the root bus. */
> + bridge = to_pci_host_bridge(bus->bridge);
> + if (platform_pci_can_wakeup(bridge->pmdata))
> + return platform_pci_bridge_wakeup(bridge->pmdata, enable);
> +
> + return 0;

And it looks like the fallback behavior is just 'return 0', if none of
the devices supported wakeup. It's weird that this already used to
happen for ACPI -- if no device/bridge implemented wakeup, we still
returned success. But now you're making this happen for platforms
without PM operations too.

This affects the behavior of pci_enable_wake below, which tries to
return an error if both PME and "platform wake" failed.

I wonder if this should just return an error code if we reached the end
(i.e., no device or bridge supported wakeup). This would technically
change the ACPI behavior, but then I think it would also be more
correct.

If you do this, that should probably be a separate patch, to be clear
we're changing the error logic before we refactor.

> +}
> +
> /**
> * pci_enable_wake - enable PCI device as wakeup event source
> * @dev: PCI device affected
> @@ -1950,13 +2014,13 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable)
> pci_pme_active(dev, true);
> else
> ret = 1;
> - error = platform_pci_set_wakeup(dev, true);
> + error = pci_set_wakeup(dev, true);
> if (ret)
> ret = error;
> if (!ret)
> dev->wakeup_prepared = true;
> } else {
> - platform_pci_set_wakeup(dev, false);
> + pci_set_wakeup(dev, false);
> pci_pme_active(dev, false);
> dev->wakeup_prepared = false;
> }
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 048668271014..dcefb9e759d7 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -47,21 +47,43 @@ int pci_probe_reset_function(struct pci_dev *dev);
> * platform; to be used during system-wide transitions from a
> * sleeping state to the working state and vice versa
> *
> - * @set_wakeup: enables/disables wakeup capability for the device
> - *
> * @need_resume: returns 'true' if the given device (which is currently
> * suspended) needs to be resumed to be configured for system
> * wakeup.
> + *
> + * @setup_dev: setup device's wakeup ability, alloc and return device's private
> + * pm data.
> + *
> + * @setup_host_bridge: setup host bridge's wakeup ability, alloc and return host
> + * bridge's private pm data.
> + *
> + * @cleanup: cleanup the private pm data and deinit wakeup ability.
> + *
> + * @can_wakeup: returns 'true' if given device is capable of waking up the
> + * system from a sleeping state.
> + *
> + * @dev_wakeup: enables/disables wakeup capability for the device.
> + *
> + * @bridge_wakeup: enables/disables wakeup capability for the bridge.
> */
> struct pci_platform_pm_ops {
> bool (*is_manageable)(struct pci_dev *dev);
> int (*set_state)(struct pci_dev *dev, pci_power_t state);
> pci_power_t (*get_state)(struct pci_dev *dev);
> pci_power_t (*choose_state)(struct pci_dev *dev);
> - int (*set_wakeup)(struct pci_dev *dev, bool enable);

I believe you're breaking pci-mid.c, which still assigns a '.set_wakeup'
callback.

> bool (*need_resume)(struct pci_dev *dev);
> + void *(*setup_dev)(struct pci_dev *dev);
> + void *(*setup_host_bridge)(struct pci_host_bridge *bridge);
> + void (*cleanup)(void *pmdata);
> + bool (*can_wakeup)(void *pmdata);
> + int (*dev_wakeup)(void *pmdata, bool enable);
> + int (*bridge_wakeup)(void *pmdata, bool enable);

You're splitting the "set_wakeup" callback into a "dev_wakeup" and a
"bridge_wakeup" function, but you're losing the "set" terminology, which
I think makes things clearer here. So, maybe "set_dev_wakeup" and
"set_bridge_wakeup"? And same for the corresponding platform_pci_*()
helpers.

Brian

> };
>
> +void *platform_pci_setup_dev(struct pci_dev *dev);
> +void *platform_pci_setup_host_bridge(struct pci_host_bridge *bridge);
> +void platform_pci_cleanup(void *pmdata);
> +
> void pci_set_platform_pm(const struct pci_platform_pm_ops *ops);
> void pci_update_current_state(struct pci_dev *dev, pci_power_t state);
> void pci_power_up(struct pci_dev *dev);
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index cdc2f83c11c5..b12c552a5522 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -809,7 +809,13 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
>
> err = device_register(&bus->dev);
> if (err)
> - goto unregister;
> + goto unregister_bridge;
> +
> + bridge->pmdata = platform_pci_setup_host_bridge(bridge);
> + if (IS_ERR(bridge->pmdata)) {
> + err = PTR_ERR(bridge->pmdata);
> + goto unregister_bus;
> + }
>
> pcibios_add_bus(bus);
>
> @@ -853,7 +859,9 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
>
> return 0;
>
> -unregister:
> +unregister_bus:
> + device_unregister(&bus->dev);
> +unregister_bridge:
> put_device(&bridge->dev);
> device_unregister(&bridge->dev);
>
> diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
> index 73a03d382590..d7a8cf1dc69f 100644
> --- a/drivers/pci/remove.c
> +++ b/drivers/pci/remove.c
> @@ -153,6 +153,8 @@ void pci_remove_root_bus(struct pci_bus *bus)
> if (!pci_is_root_bus(bus))
> return;
>
> + platform_pci_cleanup(host_bridge->pmdata);
> +
> host_bridge = to_pci_host_bridge(bus->bridge);
> list_for_each_entry_safe(child, tmp,
> &bus->devices, bus_list)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 80eaa2dbe3e9..628faa58c790 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -293,6 +293,7 @@ struct pci_dev {
> struct pci_bus *subordinate; /* bus this device bridges to */
>
> void *sysdata; /* hook for sys-specific extension */
> + void *pmdata; /* data for platform pm */
> struct proc_dir_entry *procent; /* device entry in /proc/bus/pci */
> struct pci_slot *slot; /* Physical slot this device is in */
>
> @@ -467,6 +468,7 @@ struct pci_host_bridge {
> struct pci_bus *bus; /* root bus */
> struct pci_ops *ops;
> void *sysdata;
> + void *pmdata; /* data for platform pm */
> int busnr;
> struct list_head windows; /* resource_entry */
> u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* platform IRQ swizzler */
> --
> 2.11.0
>
>

Next message: Ricardo Neri: "[PATCH v10 01/13] x86/insn-eval: Extend get_seg_base_addr() to also obtain segment limit"
Previous message: Baoquan He: "Re: [PATCH] x86/mm/64: Rename the register_page_bootmem_memmap() 'size' parameter to 'nr_pages'"
In reply to: Jeffy Chen: "[RFC PATCH v10 6/7] PCI / PM: Move acpi wakeup code to pci core"
Next in thread: Jeffy Chen: "[RFC PATCH v10 7/7] PCI / PM: Add support for the PCIe WAKE# signal for OF"
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