ACPI: scan: Extend acpi_walk_dep_device_list()

The acpi_walk_dep_device_list() function is not as generic as its
name implies, serving only to decrement the dependency count for each
dependent device of the input.

Extend it to 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.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>  # for platform/surface parts
Signed-off-by: Daniel Scally <djrscally@gmail.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 a2df7bcf4d07..2277add6da2f 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);
@@ -2107,31 +2101,70 @@ 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 *);