firmware_class: Move request_firmware_nowait() to workqueues

Oddly enough a work_struct was already part of the firmware_work
structure but nobody was using it. Instead of creating a new
kthread for each request_firmware_nowait() call just schedule the
work on the system workqueue. This should avoid some overhead
in forking new threads when they're not strictly necessary.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 7 insertions, 20 deletions

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index ae00a2fd280f..5401814c874d 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -16,10 +16,11 @@
 #include <linux/interrupt.h>
 #include <linux/bitops.h>
 #include <linux/mutex.h>
-#include <linux/kthread.h>
+#include <linux/workqueue.h>
 #include <linux/highmem.h>
 #include <linux/firmware.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
 
 #define to_dev(obj) container_of(obj, struct device, kobj)
 
@@ -630,19 +631,15 @@ struct firmware_work {
         bool uevent;
 };
 
-static int request_firmware_work_func(void *arg)
+static void request_firmware_work_func(struct work_struct *work)
 {
-        struct firmware_work *fw_work = arg;
+        struct firmware_work *fw_work;
         const struct firmware *fw;
         struct firmware_priv *fw_priv;
         long timeout;
         int ret;
 
-        if (!arg) {
-                WARN_ON(1);
-                return 0;
-        }
-
+        fw_work = container_of(work, struct firmware_work, work);
         fw_priv = _request_firmware_prepare(&fw, fw_work->name, fw_work->device,
                         fw_work->uevent, true);
         if (IS_ERR_OR_NULL(fw_priv)) {
@@ -667,8 +664,6 @@ static int request_firmware_work_func(void *arg)
 
         module_put(fw_work->module);
         kfree(fw_work);
-
-        return ret;
 }
 
 /**
@@ -694,7 +689,6 @@ request_firmware_nowait(
         const char *name, struct device *device, gfp_t gfp, void *context,
         void (*cont)(const struct firmware *fw, void *context))
 {
-        struct task_struct *task;
         struct firmware_work *fw_work;
 
         fw_work = kzalloc(sizeof (struct firmware_work), gfp);
@@ -713,15 +707,8 @@ request_firmware_nowait(
                 return -EFAULT;
         }
 
-        task = kthread_run(request_firmware_work_func, fw_work,
-                            "firmware/%s", name);
-        if (IS_ERR(task)) {
-                fw_work->cont(NULL, fw_work->context);
-                module_put(fw_work->module);
-                kfree(fw_work);
-                return PTR_ERR(task);
-        }
-
+        INIT_WORK(&fw_work->work, request_firmware_work_func);
+        schedule_work(&fw_work->work);
         return 0;
 }