diff mbox series

[SRU,M,1/2] ACPI: utils: Dynamically determine acpi_handle_list size

Message ID 20240122042616.30621-2-ivan.hu@canonical.com
State New
Headers show
Series Dynamically determine acpi_handle_list size | expand

Commit Message

ivanhu Jan. 22, 2024, 4:26 a.m. UTC 
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

BugLink: https://bugs.launchpad.net/bugs/2049733

Address a long-standing "TBD" comment in the ACPI headers regarding the
number of handles in struct acpi_handle_list.

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 [1].

Finally change the code to dynamically determine the size of the handles
table in struct acpi_handle_list and allocate it accordingly.

Update the users of to struct acpi_handle_list to take the additional
dynamic allocation into account.

Link: https://lore.kernel.org/linux-acpi/20230809094451.15473-1-ivan.hu@canonical.com # [1]
Co-developed-by: Vicki Pfau <vi@endrift.com>
Signed-off-by: Vicki Pfau <vi@endrift.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit 2e57d10a6591560724b80a628235559571f4cb8d)
Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
---
 drivers/acpi/acpi_lpss.c                      | 10 ++-
 drivers/acpi/scan.c                           |  1 +
 drivers/acpi/thermal.c                        | 29 ++++++---
 drivers/acpi/utils.c                          | 61 ++++++++++++++++++-
 .../platform/surface/surface_acpi_notify.c    | 10 ++-
 include/acpi/acpi_bus.h                       |  9 ++-
 6 files changed, 100 insertions(+), 20 deletions(-)
diff mbox series

Patch

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 539e700de4d2..3e756b9b5aa6 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -578,6 +578,7 @@  static bool acpi_lpss_dep(struct acpi_device *adev, acpi_handle handle)
 {
 	struct acpi_handle_list dep_devices;
 	acpi_status status;
+	bool ret = false;
 	int i;
 
 	if (!acpi_has_method(adev->handle, "_DEP"))
@@ -591,11 +592,14 @@  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)
-			return true;
+		if (dep_devices.handles[i] == handle) {
+			ret = true;
+			break;
+		}
 	}
 
-	return false;
+	acpi_handle_list_free(&dep_devices);
+	return ret;
 }
 
 static void acpi_lpss_link_consumer(struct device *dev1,
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 87e385542576..e3ea3868611b 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2029,6 +2029,7 @@  static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
 		mutex_unlock(&acpi_dep_list_lock);
 	}
 
+	acpi_handle_list_free(&dep_devices);
 	return count;
 }
 
diff --git a/drivers/acpi/thermal.c b/drivers/acpi/thermal.c
index 3163a40f02e3..91aeea3ad766 100644
--- a/drivers/acpi/thermal.c
+++ b/drivers/acpi/thermal.c
@@ -190,7 +190,7 @@  static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 {
 	acpi_status status;
 	unsigned long long tmp;
-	struct acpi_handle_list devices;
+	struct acpi_handle_list devices = { 0 };
 	bool valid = false;
 	int i;
 
@@ -294,7 +294,7 @@  static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 		}
 	}
 	if ((flag & ACPI_TRIPS_DEVICES) && tz->trips.passive.valid) {
-		memset(&devices, 0, sizeof(struct acpi_handle_list));
+
 		status = acpi_evaluate_reference(tz->device->handle, "_PSL",
 						 NULL, &devices);
 		if (ACPI_FAILURE(status)) {
@@ -305,12 +305,12 @@  static int acpi_thermal_trips_update(struct acpi_thermal *tz, int flag)
 			tz->trips.passive.valid = true;
 		}
 
-		if (memcmp(&tz->trips.passive.devices, &devices,
-			   sizeof(struct acpi_handle_list))) {
-			memcpy(&tz->trips.passive.devices, &devices,
-			       sizeof(struct acpi_handle_list));
-			ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
+		if (acpi_handle_list_equal(&tz->trips.passive.devices, &devices)) {
+			acpi_handle_list_free(&devices);
+			return 0;
 		}
+		ACPI_THERMAL_TRIPS_EXCEPTION(flag, tz, "device");
+		acpi_handle_list_replace(&tz->trips.passive.devices, &devices);
 	}
 	if ((flag & ACPI_TRIPS_PASSIVE) || (flag & ACPI_TRIPS_DEVICES)) {
 		if (valid != tz->trips.passive.valid)
@@ -959,6 +959,17 @@  static void acpi_thermal_check_fn(struct work_struct *work)
 	mutex_unlock(&tz->thermal_check_lock);
 }
 
+static void acpi_thermal_free_thermal_zone(struct acpi_thermal *tz)
+{
+	int i;
+
+	acpi_handle_list_free(&tz->trips.passive.devices);
+	for (i = 0; i < ACPI_THERMAL_MAX_ACTIVE; i++)
+		acpi_handle_list_free(&tz->trips.active[i].devices);
+
+	kfree(tz);
+}
+
 static int acpi_thermal_add(struct acpi_device *device)
 {
 	struct acpi_thermal *tz;
@@ -996,7 +1007,7 @@  static int acpi_thermal_add(struct acpi_device *device)
 	goto end;
 
 free_memory:
-	kfree(tz);
+	acpi_thermal_free_thermal_zone(tz);
 end:
 	return result;
 }
@@ -1012,7 +1023,7 @@  static void acpi_thermal_remove(struct acpi_device *device)
 	tz = acpi_driver_data(device);
 
 	acpi_thermal_unregister_thermal_zone(tz);
-	kfree(tz);
+	acpi_thermal_free_thermal_zone(tz);
 }
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 2ea14648a661..c6f83c21bb2a 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 +403,8 @@  acpi_evaluate_reference(acpi_handle handle,
       end:
 	if (ACPI_FAILURE(status)) {
 		list->count = 0;
-		//kfree(list->handles);
+		kfree(list->handles);
+		list->handles = NULL;
 	}
 
 	kfree(buffer.pointer);
@@ -412,6 +414,61 @@  acpi_evaluate_reference(acpi_handle handle,
 
 EXPORT_SYMBOL(acpi_evaluate_reference);
 
+/**
+ * acpi_handle_list_equal - Check if two ACPI handle lists are the same
+ * @list1: First list to compare.
+ * @list2: Second list to compare.
+ *
+ * Return true if the given ACPI handle lists are of the same size and
+ * contain the same ACPI handles in the same order.  Otherwise, return false.
+ */
+bool acpi_handle_list_equal(struct acpi_handle_list *list1,
+			    struct acpi_handle_list *list2)
+{
+	return list1->count == list2->count &&
+		!memcmp(list1->handles, list2->handles,
+		        list1->count * sizeof(acpi_handle));
+}
+EXPORT_SYMBOL_GPL(acpi_handle_list_equal);
+
+/**
+ * acpi_handle_list_replace - Replace one ACPI handle list with another
+ * @dst: ACPI handle list to replace.
+ * @src: Source ACPI handle list.
+ *
+ * Free the handles table in @dst, move the handles table from @src to @dst,
+ * copy count from @src to @dst and clear @src.
+ */
+void acpi_handle_list_replace(struct acpi_handle_list *dst,
+			      struct acpi_handle_list *src)
+{
+	if (dst->count)
+		kfree(dst->handles);
+
+	dst->count = src->count;
+	dst->handles = src->handles;
+
+	src->handles = NULL;
+	src->count = 0;
+}
+EXPORT_SYMBOL_GPL(acpi_handle_list_replace);
+
+/**
+ * acpi_handle_list_free - Free the handles table in an ACPI handle list
+ * @list: ACPI handle list to free.
+ *
+ * Free the handles table in @list and clear its count field.
+ */
+void acpi_handle_list_free(struct acpi_handle_list *list)
+{
+	if (!list->count)
+		return;
+
+	kfree(list->handles);
+	list->count = 0;
+}
+EXPORT_SYMBOL_GPL(acpi_handle_list_free);
+
 acpi_status
 acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
 {
diff --git a/drivers/platform/surface/surface_acpi_notify.c b/drivers/platform/surface/surface_acpi_notify.c
index 897cdd9c3aae..0412a644fece 100644
--- a/drivers/platform/surface/surface_acpi_notify.c
+++ b/drivers/platform/surface/surface_acpi_notify.c
@@ -741,6 +741,7 @@  static bool is_san_consumer(struct platform_device *pdev, acpi_handle handle)
 	struct acpi_handle_list dep_devices;
 	acpi_handle supplier = ACPI_HANDLE(&pdev->dev);
 	acpi_status status;
+	bool ret = false;
 	int i;
 
 	if (!acpi_has_method(handle, "_DEP"))
@@ -753,11 +754,14 @@  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)
-			return true;
+		if (dep_devices.handles[i] == supplier) {
+			ret = true;
+			break;
+		}
 	}
 
-	return false;
+	acpi_handle_list_free(&dep_devices);
+	return ret;
 }
 
 static acpi_status san_consumer_setup(acpi_handle handle, u32 lvl,
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index fb95fff23e5b..9a4782d3e738 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 */
@@ -32,6 +30,11 @@  acpi_evaluate_reference(acpi_handle handle,
 			acpi_string pathname,
 			struct acpi_object_list *arguments,
 			struct acpi_handle_list *list);
+bool acpi_handle_list_equal(struct acpi_handle_list *list1,
+			    struct acpi_handle_list *list2);
+void acpi_handle_list_replace(struct acpi_handle_list *dst,
+			      struct acpi_handle_list *src);
+void acpi_handle_list_free(struct acpi_handle_list *list);
 acpi_status
 acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
 		  struct acpi_buffer *status_buf);