[PATCH v2] ACPI: utils: Make acpi_handle_list dynamically allocated

[Vicki Pfau <vi@endrift.com>]

This fixes a long-standing "TBD" comment in the ACPI headers regarding making
the acpi_handle_list struct's size dynamic. The number 10, which along with the
comment dates back to 2.4.23, seems like it may have been arbitrarily chosen,
and isn't sufficient in all cases. This patch finally makes the size dynamic
and updates its users to handle the modified API.

Signed-off-by: Vicki Pfau <vi@endrift.com>
---
 drivers/acpi/acpi_lpss.c                      |  5 +++-
 drivers/acpi/scan.c                           |  1 +
 drivers/acpi/thermal.c                        | 23 ++++++++++++++-----
 drivers/acpi/utils.c                          |  5 ++--
 .../platform/surface/surface_acpi_notify.c    |  5 +++-
 include/acpi/acpi_bus.h                       |  4 +---
 6 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 539e700de4d2..4b3aa84faf70 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -591,10 +591,13 @@ static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
 	}
 
 	for (i = 0; i < dep_devices.count; i++) {
-		if (dep_devices.handles[i] == handle)
+		if (dep_devices.handles[i] == handle) {
+			kfree(dep_devices.handles);
 			return true;
+		}
 	}
 
+	kfree(dep_devices.handles);
 	return false;
 }
 
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 691d4b7686ee..2fbe354db0c0 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2032,6 +2032,7 @@ static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
 		mutex_unlock(&acpi_dep_list_lock);
 	}
 
+	kfree(dep_devices.handles);
 	return count;
 }
 
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 312730f8272e..48ddc56f96f6 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -307,8 +307,10 @@ static void __acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 			tz->trips.passive.trip.valid = true;
 		}
 
-		if (memcmp(&tz->trips.passive.devices, &devices,
-			   sizeof(struct acpi_handle_list))) {
+		if (&tz->trips.passive.devices.count != devices.count ||
+			   memcmp(tz->trips.passive.devices.handles,
+			   devices.handles, sizeof(acpi_handle) * devices.count)) {
+			kfree(tz->trips.passive.devices.handles);
 			memcpy(&tz->trips.passive.devices, &devices,
 			       sizeof(struct acpi_handle_list));
 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
@@ -372,8 +374,10 @@ static void __acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 				tz->trips.active[i].trip.valid = true;
 			}
 
-			if (memcmp(&tz->trips.active[i].devices, &devices,
-				   sizeof(struct acpi_handle_list))) {
+			if (&tz->trips.active[i].devices.count != devices.count ||
+				   memcmp(tz->trips.active[i].devices.handles,
+				   devices.handles, sizeof(acpi_handle) * devices.count)) {
+				kfree(tz->trips.active[i].devices.handles);
 				memcpy(&tz->trips.active[i].devices, &devices,
 				       sizeof(struct acpi_handle_list));
 				ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
@@ -391,8 +395,10 @@ static void __acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 		memset(&devices, 0, sizeof(devices));
 		status = acpi_evaluate_reference(tz->device->handle, "_TZD",
 						 NULL, &devices);
-		if (ACPI_SUCCESS(status) &&
-		    memcmp(&tz->devices, &devices, sizeof(devices))) {
+		if (ACPI_SUCCESS(status) && (tz->devices.count != devices.count ||
+		    memcmp(tz->devices.handles, devices.handles,
+		    sizeof(acpi_handle) * devices.count))) {
+			kfree(tz->devices.handles);
 			tz->devices = devices;
 			ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
 		}
@@ -974,6 +980,7 @@ static int acpi_thermal_add(struct acpi_device *device)
 static void acpi_thermal_remove(struct acpi_device *device)
 {
 	struct acpi_thermal *tz;
+	int i;
 
 	if (!device || !acpi_driver_data(device))
 		return;
@@ -986,6 +993,10 @@ static void acpi_thermal_remove(struct acpi_device *device)
 	flush_workqueue(acpi_thermal_pm_queue);
 	acpi_thermal_unregister_thermal_zone(tz);
 
+	kfree(tz->trips.passive.devices.handles);
+	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
+		kfree(tz->trips.active[i].devices.handles);
+	kfree(tz->devices.handles);
 	kfree(tz);
 }
 
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 2ea14648a661..96f821c41756 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -370,7 +370,8 @@ acpi_evaluate_reference(acpi_handle handle,
 		goto end;
 	}
 
-	if (package->package.count > ACPI_MAX_HANDLES) {
+	list->handles = kcalloc(package->package.count, sizeof(*list->handles), GFP_KERNEL);
+	if (!list->handles) {
 		kfree(package);
 		return AE_NO_MEMORY;
 	}
@@ -402,7 +403,7 @@ acpi_evaluate_reference(acpi_handle handle,
       end:
 	if (ACPI_FAILURE(status)) {
 		list->count = 0;
-		//kfree(list->handles);
+		kfree(list->handles);
 	}
 
 	kfree(buffer.pointer);
diff --git a/drivers/platform/surface/surface_acpi_notify.c b/drivers/platform/surface/surface_acpi_notify.c
index 897cdd9c3aae..6932d4b35c6c 100644
--- a/drivers/platform/surface/surface_acpi_notify.c
+++ b/drivers/platform/surface/surface_acpi_notify.c
@@ -753,10 +753,13 @@ static bool is_san_consumer(struct platform_device *pdev, acpi_handle handle)
 	}
 
 	for (i = 0; i < dep_devices.count; i++) {
-		if (dep_devices.handles[i] == supplier)
+		if (dep_devices.handles[i] == supplier) {
+			kfree(dep_devices.handles);
 			return true;
+		}
 	}
 
+	kfree(dep_devices.handles);
 	return false;
 }
 
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 254685085c82..b4bf12343a22 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -12,11 +12,9 @@
 #include <linux/device.h>
 #include <linux/property.h>
 
-/* TBD: Make dynamic */
-#define ACPI_MAX_HANDLES	10
 struct acpi_handle_list {
 	u32 count;
-	acpi_handle handles[ACPI_MAX_HANDLES];
+	acpi_handle* handles;
 };
 
 /* acpi_utils.h */
-- 
2.42.0