Re: [PATCH v4 1/8] ACPI: scan: Extend acpi_walk_dep_device_list()

[Maximilian Luz <luzmaximilian@gmail.com>]

On 5/20/21 4:09 PM, Daniel Scally wrote:
> The acpi_walk_dep_device_list() is not as generalisable as its name
> implies, serving only to decrement the dependency count for each
> dependent device of the input. Extend the function to instead accept
> a callback which can be applied to all the dependencies in acpi_dep_list.
> Replace all existing calls to the function with calls to a wrapper, passing
> a callback that applies the same dependency reduction.
> 
> Signed-off-by: Daniel Scally <djrscally@gmail.com>

Acked-by: Maximilian Luz <luzmaximilian@gmail.com>  # for platform/surface parts

> ---
> changes since v3:
> 
> 	- Most of the functions got renamed
> 	- acpi_dev_get_dependent_dev() was altered to take a struct acpi_device
> 	This had some repurcussions in the other files, mostly switching from
> 	ACPI_HANDLE() to ACPI_COMPANION().
> 	- acpi_walk_dep_device_list() was altered to check the return value of
> 	the callback on each iteration of the loop, to allow for error handling
> 	of the callbacks or breaking the loop early to save time. Andy, Wolfram,
> 	I thought this change was significant enough to drop your R-b and Ack.
> 
>   drivers/acpi/ec.c                             |  2 +-
>   drivers/acpi/pmic/intel_pmic_chtdc_ti.c       |  2 +-
>   drivers/acpi/scan.c                           | 69 ++++++++++++++-----
>   drivers/gpio/gpiolib-acpi.c                   | 10 +--
>   drivers/i2c/i2c-core-acpi.c                   |  8 +--
>   drivers/platform/surface/aggregator/core.c    |  6 +-
>   drivers/platform/surface/surface3_power.c     | 22 +++---
>   .../platform/surface/surface_acpi_notify.c    |  7 +-
>   include/acpi/acpi_bus.h                       |  7 ++
>   include/linux/acpi.h                          |  4 +-
>   10 files changed, 90 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
> index 13565629ce0a..3f7680a007a3 100644
> --- a/drivers/acpi/ec.c
> +++ b/drivers/acpi/ec.c
> @@ -1627,7 +1627,7 @@ static int acpi_ec_add(struct acpi_device *device)
>   	WARN(!ret, "Could not request EC cmd io port 0x%lx", ec->command_addr);
>   
>   	/* Reprobe devices depending on the EC */
> -	acpi_walk_dep_device_list(ec->handle);
> +	acpi_dev_clear_dependencies(device);
>   
>   	acpi_handle_debug(ec->handle, "enumerated.\n");
>   	return 0;
> diff --git a/drivers/acpi/pmic/intel_pmic_chtdc_ti.c b/drivers/acpi/pmic/intel_pmic_chtdc_ti.c
> index a5101b07611a..fef7831d0d63 100644
> --- a/drivers/acpi/pmic/intel_pmic_chtdc_ti.c
> +++ b/drivers/acpi/pmic/intel_pmic_chtdc_ti.c
> @@ -117,7 +117,7 @@ static int chtdc_ti_pmic_opregion_probe(struct platform_device *pdev)
>   		return err;
>   
>   	/* Re-enumerate devices depending on PMIC */
> -	acpi_walk_dep_device_list(ACPI_HANDLE(pdev->dev.parent));
> +	acpi_dev_clear_dependencies(ACPI_COMPANION(pdev->dev.parent));
>   	return 0;
>   }
>   
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 453eff8ec8c3..195635c3462b 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -47,12 +47,6 @@ static DEFINE_MUTEX(acpi_hp_context_lock);
>    */
>   static u64 spcr_uart_addr;
>   
> -struct acpi_dep_data {
> -	struct list_head node;
> -	acpi_handle supplier;
> -	acpi_handle consumer;
> -};
> -
>   void acpi_scan_lock_acquire(void)
>   {
>   	mutex_lock(&acpi_scan_lock);
> @@ -2111,30 +2105,69 @@ static void acpi_bus_attach(struct acpi_device *device, bool first_pass)
>   		device->handler->hotplug.notify_online(device);
>   }
>   
> -void acpi_walk_dep_device_list(acpi_handle handle)
> +static int acpi_scan_clear_dep(struct acpi_dep_data *dep, void *data)
>   {
> -	struct acpi_dep_data *dep, *tmp;
>   	struct acpi_device *adev;
>   
> +	acpi_bus_get_device(dep->consumer, &adev);
> +
> +	if (adev) {
> +		adev->dep_unmet--;
> +		if (!adev->dep_unmet)
> +			acpi_bus_attach(adev, true);
> +	}
> +
> +	list_del(&dep->node);
> +	kfree(dep);
> +
> +	return 0;
> +}
> +
> +/**
> + * acpi_walk_dep_device_list - Apply a callback to every entry in acpi_dep_list
> + * @handle:	The ACPI handle of the supplier device
> + * @callback:	Pointer to the callback function to apply
> + * @data:	Pointer to some data to pass to the callback
> + *
> + * The return value of the callback determines this function's behaviour. If 0
> + * is returned we continue to iterate over acpi_dep_list. If a positive value
> + * is returned then the loop is broken but this function returns 0. If a
> + * negative value is returned by the callback then the loop is broken and that
> + * value is returned as the final error.
> + */
> +int acpi_walk_dep_device_list(acpi_handle handle,
> +			      int (*callback)(struct acpi_dep_data *, void *),
> +			      void *data)
> +{
> +	struct acpi_dep_data *dep, *tmp;
> +	int ret;
> +
>   	mutex_lock(&acpi_dep_list_lock);
>   	list_for_each_entry_safe(dep, tmp, &acpi_dep_list, node) {
>   		if (dep->supplier == handle) {
> -			acpi_bus_get_device(dep->consumer, &adev);
> -
> -			if (adev) {
> -				adev->dep_unmet--;
> -				if (!adev->dep_unmet)
> -					acpi_bus_attach(adev, true);
> -			}
> -
> -			list_del(&dep->node);
> -			kfree(dep);
> +			ret = callback(dep, data);
> +			if (ret)
> +				break;
>   		}
>   	}
>   	mutex_unlock(&acpi_dep_list_lock);
> +
> +	return ret > 0 ? 0 : ret;
>   }
>   EXPORT_SYMBOL_GPL(acpi_walk_dep_device_list);
>   
> +/**
> + * acpi_dev_clear_dependencies - Inform consumers that the device is now active
> + * @supplier: Pointer to the supplier &struct acpi_device
> + *
> + * Clear dependencies on the given device.
> + */
> +void acpi_dev_clear_dependencies(struct acpi_device *supplier)
> +{
> +	acpi_walk_dep_device_list(supplier->handle, acpi_scan_clear_dep, NULL);
> +}
> +EXPORT_SYMBOL_GPL(acpi_dev_clear_dependencies);
> +
>   /**
>    * acpi_bus_scan - Add ACPI device node objects in a given namespace scope.
>    * @handle: Root of the namespace scope to scan.
> diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
> index 3ef22a3c104d..5b4111e4be3f 100644
> --- a/drivers/gpio/gpiolib-acpi.c
> +++ b/drivers/gpio/gpiolib-acpi.c
> @@ -1233,14 +1233,14 @@ static void acpi_gpiochip_scan_gpios(struct acpi_gpio_chip *achip)
>   void acpi_gpiochip_add(struct gpio_chip *chip)
>   {
>   	struct acpi_gpio_chip *acpi_gpio;
> -	acpi_handle handle;
> +	struct acpi_device *adev;
>   	acpi_status status;
>   
>   	if (!chip || !chip->parent)
>   		return;
>   
> -	handle = ACPI_HANDLE(chip->parent);
> -	if (!handle)
> +	adev = ACPI_COMPANION(chip->parent);
> +	if (!adev)
>   		return;
>   
>   	acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
> @@ -1254,7 +1254,7 @@ void acpi_gpiochip_add(struct gpio_chip *chip)
>   	INIT_LIST_HEAD(&acpi_gpio->events);
>   	INIT_LIST_HEAD(&acpi_gpio->deferred_req_irqs_list_entry);
>   
> -	status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
> +	status = acpi_attach_data(adev->handle, acpi_gpio_chip_dh, acpi_gpio);
>   	if (ACPI_FAILURE(status)) {
>   		dev_err(chip->parent, "Failed to attach ACPI GPIO chip\n");
>   		kfree(acpi_gpio);
> @@ -1263,7 +1263,7 @@ void acpi_gpiochip_add(struct gpio_chip *chip)
>   
>   	acpi_gpiochip_request_regions(acpi_gpio);
>   	acpi_gpiochip_scan_gpios(acpi_gpio);
> -	acpi_walk_dep_device_list(handle);
> +	acpi_dev_clear_dependencies(adev);
>   }
>   
>   void acpi_gpiochip_remove(struct gpio_chip *chip)
> diff --git a/drivers/i2c/i2c-core-acpi.c b/drivers/i2c/i2c-core-acpi.c
> index 8ceaa88dd78f..6f0aa0ed3241 100644
> --- a/drivers/i2c/i2c-core-acpi.c
> +++ b/drivers/i2c/i2c-core-acpi.c
> @@ -259,8 +259,8 @@ static acpi_status i2c_acpi_add_device(acpi_handle handle, u32 level,
>    */
>   void i2c_acpi_register_devices(struct i2c_adapter *adap)
>   {
> +	struct acpi_device *adev;
>   	acpi_status status;
> -	acpi_handle handle;
>   
>   	if (!has_acpi_companion(&adap->dev))
>   		return;
> @@ -275,11 +275,11 @@ void i2c_acpi_register_devices(struct i2c_adapter *adap)
>   	if (!adap->dev.parent)
>   		return;
>   
> -	handle = ACPI_HANDLE(adap->dev.parent);
> -	if (!handle)
> +	adev = ACPI_COMPANION(adap->dev.parent);
> +	if (!adev)
>   		return;
>   
> -	acpi_walk_dep_device_list(handle);
> +	acpi_dev_clear_dependencies(adev);
>   }
>   
>   static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {
> diff --git a/drivers/platform/surface/aggregator/core.c b/drivers/platform/surface/aggregator/core.c
> index 8dc2c267bcd6..517f774a6e60 100644
> --- a/drivers/platform/surface/aggregator/core.c
> +++ b/drivers/platform/surface/aggregator/core.c
> @@ -621,8 +621,8 @@ static const struct acpi_gpio_mapping ssam_acpi_gpios[] = {
>   
>   static int ssam_serial_hub_probe(struct serdev_device *serdev)
>   {
> +	struct acpi_device *ssh = ACPI_COMPANION(&serdev->dev);
>   	struct ssam_controller *ctrl;
> -	acpi_handle *ssh = ACPI_HANDLE(&serdev->dev);
>   	acpi_status astatus;
>   	int status;
>   
> @@ -652,7 +652,7 @@ static int ssam_serial_hub_probe(struct serdev_device *serdev)
>   	if (status)
>   		goto err_devopen;
>   
> -	astatus = ssam_serdev_setup_via_acpi(ssh, serdev);
> +	astatus = ssam_serdev_setup_via_acpi(ssh->handle, serdev);
>   	if (ACPI_FAILURE(astatus)) {
>   		status = -ENXIO;
>   		goto err_devinit;
> @@ -706,7 +706,7 @@ static int ssam_serial_hub_probe(struct serdev_device *serdev)
>   	 *       For now let's thus default power/wakeup to false.
>   	 */
>   	device_set_wakeup_capable(&serdev->dev, true);
> -	acpi_walk_dep_device_list(ssh);
> +	acpi_dev_clear_dependencies(ssh);
>   
>   	return 0;
>   
> diff --git a/drivers/platform/surface/surface3_power.c b/drivers/platform/surface/surface3_power.c
> index cc4f9cba6856..dea82aa1abd4 100644
> --- a/drivers/platform/surface/surface3_power.c
> +++ b/drivers/platform/surface/surface3_power.c
> @@ -446,12 +446,12 @@ mshw0011_space_handler(u32 function, acpi_physical_address command,
>   
>   static int mshw0011_install_space_handler(struct i2c_client *client)
>   {
> -	acpi_handle handle;
> +	struct acpi_device *adev;
>   	struct mshw0011_handler_data *data;
>   	acpi_status status;
>   
> -	handle = ACPI_HANDLE(&client->dev);
> -	if (!handle)
> +	adev = ACPI_COMPANION(&client->dev);
> +	if (!adev)
>   		return -ENODEV;
>   
>   	data = kzalloc(sizeof(struct mshw0011_handler_data),
> @@ -460,25 +460,25 @@ static int mshw0011_install_space_handler(struct i2c_client *client)
>   		return -ENOMEM;
>   
>   	data->client = client;
> -	status = acpi_bus_attach_private_data(handle, (void *)data);
> +	status = acpi_bus_attach_private_data(adev->handle, (void *)data);
>   	if (ACPI_FAILURE(status)) {
>   		kfree(data);
>   		return -ENOMEM;
>   	}
>   
> -	status = acpi_install_address_space_handler(handle,
> -				ACPI_ADR_SPACE_GSBUS,
> -				&mshw0011_space_handler,
> -				NULL,
> -				data);
> +	status = acpi_install_address_space_handler(adev->handle,
> +						    ACPI_ADR_SPACE_GSBUS,
> +						    &mshw0011_space_handler,
> +						    NULL,
> +						    data);
>   	if (ACPI_FAILURE(status)) {
>   		dev_err(&client->dev, "Error installing i2c space handler\n");
> -		acpi_bus_detach_private_data(handle);
> +		acpi_bus_detach_private_data(adev->handle);
>   		kfree(data);
>   		return -ENOMEM;
>   	}
>   
> -	acpi_walk_dep_device_list(handle);
> +	acpi_dev_clear_dependencies(adev);
>   	return 0;
>   }
>   
> diff --git a/drivers/platform/surface/surface_acpi_notify.c b/drivers/platform/surface/surface_acpi_notify.c
> index ef9c1f8e8336..8339988d95c1 100644
> --- a/drivers/platform/surface/surface_acpi_notify.c
> +++ b/drivers/platform/surface/surface_acpi_notify.c
> @@ -798,7 +798,7 @@ static int san_consumer_links_setup(struct platform_device *pdev)
>   
>   static int san_probe(struct platform_device *pdev)
>   {
> -	acpi_handle san = ACPI_HANDLE(&pdev->dev);
> +	struct acpi_device *san = ACPI_COMPANION(&pdev->dev);
>   	struct ssam_controller *ctrl;
>   	struct san_data *data;
>   	acpi_status astatus;
> @@ -821,7 +821,8 @@ static int san_probe(struct platform_device *pdev)
>   
>   	platform_set_drvdata(pdev, data);
>   
> -	astatus = acpi_install_address_space_handler(san, ACPI_ADR_SPACE_GSBUS,
> +	astatus = acpi_install_address_space_handler(san->handle,
> +						     ACPI_ADR_SPACE_GSBUS,
>   						     &san_opreg_handler, NULL,
>   						     &data->info);
>   	if (ACPI_FAILURE(astatus))
> @@ -835,7 +836,7 @@ static int san_probe(struct platform_device *pdev)
>   	if (status)
>   		goto err_install_dev;
>   
> -	acpi_walk_dep_device_list(san);
> +	acpi_dev_clear_dependencies(san);
>   	return 0;
>   
>   err_install_dev:
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 3a82faac5767..0b2c4f170f4d 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -280,6 +280,12 @@ struct acpi_device_power {
>   	struct acpi_device_power_state states[ACPI_D_STATE_COUNT];	/* Power states (D0-D3Cold) */
>   };
>   
> +struct acpi_dep_data {
> +	struct list_head node;
> +	acpi_handle supplier;
> +	acpi_handle consumer;
> +};
> +
>   /* Performance Management */
>   
>   struct acpi_device_perf_flags {
> @@ -685,6 +691,7 @@ static inline bool acpi_device_can_poweroff(struct acpi_device *adev)
>   
>   bool acpi_dev_hid_uid_match(struct acpi_device *adev, const char *hid2, const char *uid2);
>   
> +void acpi_dev_clear_dependencies(struct acpi_device *supplier);
>   struct acpi_device *
>   acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv);
>   struct acpi_device *
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index c60745f657e9..170b9bebdb2b 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -666,7 +666,9 @@ extern bool acpi_driver_match_device(struct device *dev,
>   				     const struct device_driver *drv);
>   int acpi_device_uevent_modalias(struct device *, struct kobj_uevent_env *);
>   int acpi_device_modalias(struct device *, char *, int);
> -void acpi_walk_dep_device_list(acpi_handle handle);
> +int acpi_walk_dep_device_list(acpi_handle handle,
> +			      int (*callback)(struct acpi_dep_data *, void *),
> +			      void *data);
>   
>   struct platform_device *acpi_create_platform_device(struct acpi_device *,
>   						    struct property_entry *);
> 

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