2 files changed, 64 insertions, 35 deletions

diff --git a/Documentation/dmatest.txt b/Documentation/dmatest.txt
index 0beb4b68d81f..dd77a81bdb80 100644
--- a/Documentation/dmatest.txt
+++ b/Documentation/dmatest.txt
@@ -39,17 +39,24 @@ stops.
 
 Note that running a new test will not stop any in progress test.
 
-The following command should return actual state of the test.
-        % cat /sys/kernel/debug/dmatest/run
+The following command returns the state of the test.
+        % cat /sys/module/dmatest/parameters/run
 
-To wait for test done the user may perform a busy loop that checks the state.
+To wait for test completion userpace can poll 'run' until it is false, or use
+the wait parameter.  Specifying 'wait=1' when loading the module causes module
+initialization to pause until a test run has completed, while reading
+/sys/module/dmatest/parameters/wait waits for any running test to complete
+before returning.  For example, the following scripts wait for 42 tests
+to complete before exiting.  Note that if 'iterations' is set to 'infinite' then
+waiting is disabled.
 
-        % while [ $(cat /sys/module/dmatest/parameters/run) = "Y" ]
-        > do
-        >       echo -n "."
-        >       sleep 1
-        > done
-        > echo
+Example:
+        % modprobe dmatest run=1 iterations=42 wait=1
+        % modprobe -r dmatest
+...or:
+        % modprobe dmatest run=1 iterations=42
+        % cat /sys/module/dmatest/parameters/wait
+        % modprobe -r dmatest
 
         Part 3 - When built-in in the kernel...
 
@@ -79,7 +86,7 @@ number of tests executed, number that failed, and a result code.
 
 Example:
         % dmesg | tail -n 1
-        dmatest: dma3chan0-copy0: summary 400000 tests, 0 failures iops: 61524 KB/s 246098 (0)
+        dmatest: dma0chan0-copy0: summary 1 test, 0 failures 1000 iops 100000 KB/s (0)
 
 The details of a data miscompare error are also emitted, but do not follow the
 above format.
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 26b502069638..dd4d84d556d5 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -161,6 +161,43 @@ struct dmatest_chan {
         struct list_head        threads;
 };
 
+static DECLARE_WAIT_QUEUE_HEAD(thread_wait);
+static bool wait;
+
+static bool is_threaded_test_run(struct dmatest_info *info)
+{
+        struct dmatest_chan *dtc;
+
+        list_for_each_entry(dtc, &info->channels, node) {
+                struct dmatest_thread *thread;
+
+                list_for_each_entry(thread, &dtc->threads, node) {
+                        if (!thread->done)
+                                return true;
+                }
+        }
+
+        return false;
+}
+
+static int dmatest_wait_get(char *val, const struct kernel_param *kp)
+{
+        struct dmatest_info *info = &test_info;
+        struct dmatest_params *params = &info->params;
+
+        if (params->iterations)
+                wait_event(thread_wait, !is_threaded_test_run(info));
+        wait = true;
+        return param_get_bool(val, kp);
+}
+
+static struct kernel_param_ops wait_ops = {
+        .get = dmatest_wait_get,
+        .set = param_set_bool,
+};
+module_param_cb(wait, &wait_ops, &wait, S_IRUGO);
+MODULE_PARM_DESC(wait, "Wait for tests to complete (default: false)");
+
 static bool dmatest_match_channel(struct dmatest_params *params,
                 struct dma_chan *chan)
 {
@@ -660,12 +697,7 @@ err_thread_type:
                 dmaengine_terminate_all(chan);
 
         thread->done = true;
-
-        if (params->iterations > 0)
-                while (!kthread_should_stop()) {
-                        DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wait_dmatest_exit);
-                        interruptible_sleep_on(&wait_dmatest_exit);
-                }
+        wake_up(&thread_wait);
 
         return ret;
 }
@@ -681,6 +713,7 @@ static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
                 pr_debug("thread %s exited with status %d\n",
                          thread->task->comm, ret);
                 list_del(&thread->node);
+                put_task_struct(thread->task);
                 kfree(thread);
         }
 
@@ -719,18 +752,19 @@ static int dmatest_add_threads(struct dmatest_info *info,
                 thread->chan = dtc->chan;
                 thread->type = type;
                 smp_wmb();
-                thread->task = kthread_run(dmatest_func, thread, "%s-%s%u",
+                thread->task = kthread_create(dmatest_func, thread, "%s-%s%u",
                                 dma_chan_name(chan), op, i);
                 if (IS_ERR(thread->task)) {
-                        pr_warn("Failed to run thread %s-%s%u\n",
+                        pr_warn("Failed to create thread %s-%s%u\n",
                                 dma_chan_name(chan), op, i);
                         kfree(thread);
                         break;
                 }
 
                 /* srcbuf and dstbuf are allocated by the thread itself */
-
+                get_task_struct(thread->task);
                 list_add_tail(&thread->node, &dtc->threads);
+                wake_up_process(thread->task);
         }
 
         return i;
@@ -863,22 +897,6 @@ static void restart_threaded_test(struct dmatest_info *info, bool run)
         run_threaded_test(info);
 }
 
-static bool is_threaded_test_run(struct dmatest_info *info)
-{
-        struct dmatest_chan *dtc;
-
-        list_for_each_entry(dtc, &info->channels, node) {
-                struct dmatest_thread *thread;
-
-                list_for_each_entry(thread, &dtc->threads, node) {
-                        if (!thread->done)
-                                return true;
-                }
-        }
-
-        return false;
-}
-
 static int dmatest_run_get(char *val, const struct kernel_param *kp)
 {
         struct dmatest_info *info = &test_info;
@@ -920,6 +938,7 @@ static int dmatest_run_set(const char *val, const struct kernel_param *kp)
 static int __init dmatest_init(void)
 {
         struct dmatest_info *info = &test_info;
+        struct dmatest_params *params = &info->params;
 
         if (dmatest_run) {
                 mutex_lock(&info->lock);
@@ -927,6 +946,9 @@ static int __init dmatest_init(void)
                 mutex_unlock(&info->lock);
         }
 
+        if (params->iterations && wait)
+                wait_event(thread_wait, !is_threaded_test_run(info));
+
         /* module parameters are stable, inittime tests are started,
          * let userspace take over 'run' control
          */