From: Rafael J. Wysocki rafael.j.wysocki@intel.com
[ Upstream commit c1013ff7a5472db637c56bb6237f8343398c03a7 ]
The upfront allocation of new_bus_id is done to avoid allocating memory under acpi_device_lock, but it doesn't really help, because (1) it leads to many unnecessary memory allocations for _ADR devices, (2) kstrdup_const() is run under that lock anyway and (3) it complicates the code.
Rearrange acpi_device_add() to allocate memory for a new struct acpi_device_bus_id instance only when necessary, eliminate a redundant local variable from it and reduce the number of labels in there.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Reviewed-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/scan.c | 57 +++++++++++++++++++++------------------------ 1 file changed, 26 insertions(+), 31 deletions(-)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 22566b4b3150..1efeb8f78ae4 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -623,12 +623,23 @@ void acpi_bus_put_acpi_device(struct acpi_device *adev) put_device(&adev->dev); }
+static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id) +{ + struct acpi_device_bus_id *acpi_device_bus_id; + + /* Find suitable bus_id and instance number in acpi_bus_id_list. */ + list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) { + if (!strcmp(acpi_device_bus_id->bus_id, dev_id)) + return acpi_device_bus_id; + } + return NULL; +} + int acpi_device_add(struct acpi_device *device, void (*release)(struct device *)) { + struct acpi_device_bus_id *acpi_device_bus_id; int result; - struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id; - int found = 0;
if (device->handle) { acpi_status status; @@ -654,38 +665,26 @@ int acpi_device_add(struct acpi_device *device, INIT_LIST_HEAD(&device->del_list); mutex_init(&device->physical_node_lock);
- new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL); - if (!new_bus_id) { - pr_err(PREFIX "Memory allocation error\n"); - result = -ENOMEM; - goto err_detach; - } - mutex_lock(&acpi_device_lock); - /* - * Find suitable bus_id and instance number in acpi_bus_id_list - * If failed, create one and link it into acpi_bus_id_list - */ - list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) { - if (!strcmp(acpi_device_bus_id->bus_id, - acpi_device_hid(device))) { - acpi_device_bus_id->instance_no++; - found = 1; - kfree(new_bus_id); - break; + + acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device)); + if (acpi_device_bus_id) { + acpi_device_bus_id->instance_no++; + } else { + acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id), + GFP_KERNEL); + if (!acpi_device_bus_id) { + result = -ENOMEM; + goto err_unlock; } - } - if (!found) { - acpi_device_bus_id = new_bus_id; acpi_device_bus_id->bus_id = kstrdup_const(acpi_device_hid(device), GFP_KERNEL); if (!acpi_device_bus_id->bus_id) { - pr_err(PREFIX "Memory allocation error for bus id\n"); + kfree(acpi_device_bus_id); result = -ENOMEM; - goto err_free_new_bus_id; + goto err_unlock; }
- acpi_device_bus_id->instance_no = 0; list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list); } dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no); @@ -720,13 +719,9 @@ int acpi_device_add(struct acpi_device *device, list_del(&device->node); list_del(&device->wakeup_list);
- err_free_new_bus_id: - if (!found) - kfree(new_bus_id); - + err_unlock: mutex_unlock(&acpi_device_lock);
- err_detach: acpi_detach_data(device->handle, acpi_scan_drop_device); return result; }