Add support for running tests on multiple channels simultaneously as the
driver currently limits to 1 channel per test run. This will add support
for stress testing DMA controllers with multi channel capabilities.
This is done by adding a callback function to the "channel" parameter
that registers the requested channel prior to the "run" parameter being
set to 1. Each time the "channel" parameter is populated with a new
dma channel, a new test is appended to the thread queue. Once the "run"
parameter is set to 1, the test will kick start all pending threads.
Signed-off-by: Seraj Alijan <seraj.alijan@xxxxxxxxxxx>
---
drivers/dma/dmatest.c | 109 +++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 89 insertions(+), 20 deletions(-)
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index aa1712b..8ce3b06 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -27,11 +27,6 @@ static unsigned int test_buf_size = 16384;
module_param(test_buf_size, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(test_buf_size, "Size of the memcpy test buffer");
-static char test_channel[20];
-module_param_string(channel, test_channel, sizeof(test_channel),
- S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)");
-
static char test_device[32];
module_param_string(device, test_device, sizeof(test_device),
S_IRUGO | S_IWUSR);
@@ -139,6 +134,21 @@ static bool dmatest_run;
module_param_cb(run, &run_ops, &dmatest_run, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(run, "Run the test (default: false)");
+static int dmatest_chan_set(const char *val, const struct kernel_param *kp);
+static int dmatest_chan_get(char *val, const struct kernel_param *kp);
+static const struct kernel_param_ops multi_chan_ops = {
+ .set = dmatest_chan_set,
+ .get = dmatest_chan_get,
+};
+
+static char test_channel[20];
+static struct kparam_string newchan_kps = {
+ .string = test_channel,
+ .maxlen = 20,
+};
+module_param_cb(channel, &multi_chan_ops, &newchan_kps, 0644);
+MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)");
+
/* Maximum amount of mismatched bytes in buffer to print */
#define MAX_ERROR_COUNT 32
@@ -179,6 +189,7 @@ struct dmatest_thread {
wait_queue_head_t done_wait;
struct dmatest_done test_done;
bool done;
+ bool pending;
};
struct dmatest_chan {
@@ -206,6 +217,22 @@ static bool is_threaded_test_run(struct dmatest_info *info)
return false;
}
+static bool is_threaded_test_pending(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->pending)
+ return true;
+ }
+ }
+
+ return false;
+}
+
static int dmatest_wait_get(char *val, const struct kernel_param *kp)
{
struct dmatest_info *info = &test_info;
@@ -476,6 +503,7 @@ static int dmatest_func(void *data)
ret = -ENOMEM;
smp_rmb();
+ thread->pending = false;
info = thread->info;
params = &info->params;
chan = thread->chan;
@@ -886,7 +914,7 @@ static int dmatest_add_threads(struct dmatest_info *info,
/* 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);
+ thread->pending = true;
}
return i;
@@ -932,7 +960,7 @@ static int dmatest_add_channel(struct dmatest_info *info,
thread_count += cnt > 0 ? cnt : 0;
}
- pr_info("Started %u threads using %s\n",
+ pr_info("Added %u threads using %s\n",
thread_count, dma_chan_name(chan));
list_add_tail(&dtc->node, &info->channels);
@@ -977,7 +1005,7 @@ static void request_channels(struct dmatest_info *info,
}
}
-static void run_threaded_test(struct dmatest_info *info)
+static void add_threaded_test(struct dmatest_info *info)
{
struct dmatest_params *params = &info->params;
@@ -1000,6 +1028,19 @@ static void run_threaded_test(struct dmatest_info *info)
request_channels(info, DMA_PQ);
}
+static void run_pending_tests(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) {
+ wake_up_process(thread->task);
+ }
+ }
+}
+
static void stop_threaded_test(struct dmatest_info *info)
{
struct dmatest_chan *dtc, *_dtc;
@@ -1016,7 +1057,7 @@ static void stop_threaded_test(struct dmatest_info *info)
info->nr_channels = 0;
}
-static void restart_threaded_test(struct dmatest_info *info, bool run)
+static void start_threaded_tests(struct dmatest_info *info)
{
/* we might be called early to set run=, defer running until all
* parameters have been evaluated
@@ -1024,11 +1065,7 @@ static void restart_threaded_test(struct dmatest_info *info, bool run)
if (!info->did_init)
return;
- /* Stop any running test first */
- stop_threaded_test(info);
-
- /* Run test with new parameters */
- run_threaded_test(info);
+ run_pending_tests(info);
}
static int dmatest_run_get(char *val, const struct kernel_param *kp)
@@ -1039,7 +1076,8 @@ static int dmatest_run_get(char *val, const struct kernel_param *kp)
if (is_threaded_test_run(info)) {
dmatest_run = true;
} else {
- stop_threaded_test(info);
+ if (!is_threaded_test_pending(info))
+ stop_threaded_test(info);
dmatest_run = false;
}
mutex_unlock(&info->lock);
@@ -1057,18 +1095,48 @@ static int dmatest_run_set(const char *val, const struct kernel_param *kp)
if (ret) {
mutex_unlock(&info->lock);
return ret;
+ } else if (dmatest_run && is_threaded_test_pending(info)) {
+ start_threaded_tests(info);
}
- if (is_threaded_test_run(info))
- ret = -EBUSY;
- else if (dmatest_run)
- restart_threaded_test(info, dmatest_run);
+ mutex_unlock(&info->lock);
+
+ return ret;
+}
+
+static int dmatest_chan_set(const char *val, const struct kernel_param *kp)
+{
+ struct dmatest_info *info = &test_info;
+ int ret;
+ mutex_lock(&info->lock);
+ ret = param_set_copystring(val, kp);
+ if (ret) {
+ mutex_unlock(&info->lock);
+ return ret;
+ }
+ if (!is_threaded_test_run(info) && !is_threaded_test_pending(info))
+ stop_threaded_test(info);
+ add_threaded_test(info);
mutex_unlock(&info->lock);
return ret;
}
+static int dmatest_chan_get(char *val, const struct kernel_param *kp)
+{
+ struct dmatest_info *info = &test_info;
+
+ mutex_lock(&info->lock);
+ if (!is_threaded_test_run(info) && !is_threaded_test_pending(info)) {
+ stop_threaded_test(info);
+ strlcpy(test_channel, "", sizeof(test_channel));
+ }
+ mutex_unlock(&info->lock);
+
+ return param_get_string(val, kp);
+}
+
static int __init dmatest_init(void)
{
struct dmatest_info *info = &test_info;
@@ -1076,7 +1144,8 @@ static int __init dmatest_init(void)
if (dmatest_run) {
mutex_lock(&info->lock);
- run_threaded_test(info);
+ add_threaded_test(info);
+ run_pending_tests(info);
mutex_unlock(&info->lock);
}
--
2.7.4
