[PATCH] ACPI: scan: Simplify acpi_table_events_fn()

Rafael J. Wysocki
2021-06-16T14:05:55Z

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Notice that the table field of struct acpi_table_events_work is never
read and its event field is always equal to ACPI_TABLE_EVENT_LOAD, so
both of them are redundant.

Accordingly, drop struct acpi_table_events_work and use struct
work_struct directly instead of it, simplify acpi_scan_table_handler()
and rename it to acpi_scan_table_notify().

Moreover, make acpi_bus_table_handler() check the event code against
ACPI_TABLE_EVENT_LOAD before calling acpi_scan_table_notify(), so it
is not necessary to do that check in the latter.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/bus.c | 3 ++-
drivers/acpi/internal.h | 2 +-
drivers/acpi/scan.c | 38 ++++++++++----------------------------
3 files changed, 13 insertions(+), 30 deletions(-)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -2471,46 +2471,28 @@ int __init __acpi_probe_device_table(str
return count;
}

-struct acpi_table_events_work {
- struct work_struct work;
- void *table;
- u32 event;
-};
-
static void acpi_table_events_fn(struct work_struct *work)
{
- struct acpi_table_events_work *tew;
-
- tew = container_of(work, struct acpi_table_events_work, work);
-
- if (tew->event == ACPI_TABLE_EVENT_LOAD) {
- acpi_scan_lock_acquire();
- acpi_bus_scan(ACPI_ROOT_OBJECT);
- acpi_scan_lock_release();
- }
+ acpi_scan_lock_acquire();
+ acpi_bus_scan(ACPI_ROOT_OBJECT);
+ acpi_scan_lock_release();

- kfree(tew);
+ kfree(work);
}

-void acpi_scan_table_handler(u32 event, void *table, void *context)
+void acpi_scan_table_notify(void)
{
- struct acpi_table_events_work *tew;
+ struct work_struct *work;

if (!acpi_scan_initialized)
return;

- if (event != ACPI_TABLE_EVENT_LOAD)
+ work = kmalloc(sizeof(*work), GFP_KERNEL);
+ if (!work)
return;

- tew = kmalloc(sizeof(*tew), GFP_KERNEL);
- if (!tew)
- return;
-
- INIT_WORK(&tew->work, acpi_table_events_fn);
- tew->table = table;
- tew->event = event;
-
- schedule_work(&tew->work);
+ INIT_WORK(work, acpi_table_events_fn);
+ schedule_work(work);
}

int acpi_reconfig_notifier_register(struct notifier_block *nb)
Index: linux-pm/drivers/acpi/bus.c
===================================================================
--- linux-pm.orig/drivers/acpi/bus.c
+++ linux-pm/drivers/acpi/bus.c
@@ -1195,7 +1195,8 @@ void __init acpi_subsystem_init(void)

static acpi_status acpi_bus_table_handler(u32 event, void *table, void *context)
{
- acpi_scan_table_handler(event, table, context);
+ if (event == ACPI_TABLE_EVENT_LOAD)
+ acpi_scan_table_notify();

return acpi_sysfs_table_handler(event, table, context);
}
Index: linux-pm/drivers/acpi/internal.h
===================================================================
--- linux-pm.orig/drivers/acpi/internal.h
+++ linux-pm/drivers/acpi/internal.h
@@ -86,7 +86,7 @@ void acpi_device_hotplug(struct acpi_dev
bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent);

acpi_status acpi_sysfs_table_handler(u32 event, void *table, void *context);
-void acpi_scan_table_handler(u32 event, void *table, void *context);
+void acpi_scan_table_notify(void);

/* --------------------------------------------------------------------------
Device Node Initialization / Removal