From d53513d5dc285d9a95a534fc41c5c08af6b60eac Mon Sep 17 00:00:00 2001 From: Seraj Alijan Date: Mon, 10 Dec 2018 08:52:31 +0000 Subject: [PATCH] dmaengine: dmatest: Add support for multi channel testing 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 Signed-off-by: Vinod Koul --- drivers/dma/dmatest.c | 200 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 179 insertions(+), 21 deletions(-) diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index 28deaa084257..d19277234c2d 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 +134,28 @@ 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)"); + +static int dmatest_test_list_get(char *val, const struct kernel_param *kp); +static const struct kernel_param_ops test_list_ops = { + .get = dmatest_test_list_get, +}; +module_param_cb(test_list, &test_list_ops, NULL, 0444); +MODULE_PARM_DESC(test_list, "Print current test list"); + /* Maximum amount of mismatched bytes in buffer to print */ #define MAX_ERROR_COUNT 32 @@ -179,6 +196,7 @@ struct dmatest_thread { wait_queue_head_t done_wait; struct dmatest_done test_done; bool done; + bool pending; }; struct dmatest_chan { @@ -206,6 +224,22 @@ 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 +510,7 @@ static int dmatest_func(void *data) ret = -ENOMEM; smp_rmb(); + thread->pending = false; info = thread->info; params = &info->params; chan = thread->chan; @@ -884,7 +919,7 @@ 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; @@ -930,7 +965,7 @@ 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); @@ -975,7 +1010,7 @@ 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; @@ -998,6 +1033,24 @@ 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; + unsigned int thread_count = 0; + + list_for_each_entry(dtc, &info->channels, node) { + struct dmatest_thread *thread; + + thread_count = 0; + list_for_each_entry(thread, &dtc->threads, node) { + wake_up_process(thread->task); + thread_count++; + } + pr_info("Started %u threads using %s\n", + thread_count, dma_chan_name(dtc->chan)); + } +} + static void stop_threaded_test(struct dmatest_info *info) { struct dmatest_chan *dtc, *_dtc; @@ -1014,7 +1067,7 @@ 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 @@ -1022,11 +1075,7 @@ 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) @@ -1037,7 +1086,8 @@ 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); @@ -1055,18 +1105,125 @@ 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) { + if (is_threaded_test_pending(info)) + start_threaded_tests(info); + else + pr_info("Could not start test, no channels configured\n"); + } else { + stop_threaded_test(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; + struct dmatest_chan *dtc; + char chan_reset_val[20]; + int ret = 0; + + mutex_lock(&info->lock); + ret = param_set_copystring(val, kp); + if (ret) { + mutex_unlock(&info->lock); + return ret; + } + /*Clear any previously run threads */ + if (!is_threaded_test_run(info) && !is_threaded_test_pending(info)) + stop_threaded_test(info); + /* Reject channels that are already registered */ + if (is_threaded_test_pending(info)) { + list_for_each_entry(dtc, &info->channels, node) { + if (strcmp(dma_chan_name(dtc->chan), + strim(test_channel)) == 0) { + dtc = list_last_entry(&info->channels, + struct dmatest_chan, + node); + strlcpy(chan_reset_val, + dma_chan_name(dtc->chan), + sizeof(chan_reset_val)); + ret = -EBUSY; + goto add_chan_err; + } + } + } + + add_threaded_test(info); + + /* Check if channel was added successfully */ + dtc = list_last_entry(&info->channels, struct dmatest_chan, node); + + if (dtc->chan) { + /* + * if new channel was not successfully added, revert the + * "test_channel" string to the name of the last successfully + * added channel. exception for when users issues empty string + * to channel parameter. + */ + if ((strcmp(dma_chan_name(dtc->chan), strim(test_channel)) != 0) + && (strcmp("", strim(test_channel)) != 0)) { + ret = -EINVAL; + strlcpy(chan_reset_val, dma_chan_name(dtc->chan), + sizeof(chan_reset_val)); + goto add_chan_err; + } + + } else { + /* Clear test_channel if no channels were added successfully */ + strlcpy(chan_reset_val, "", sizeof(chan_reset_val)); + ret = -EBUSY; + goto add_chan_err; + } + + mutex_unlock(&info->lock); + + return ret; + +add_chan_err: + param_set_copystring(chan_reset_val, kp); + 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 dmatest_test_list_get(char *val, const struct kernel_param *kp) +{ + struct dmatest_info *info = &test_info; + struct dmatest_chan *dtc; + unsigned int thread_count = 0; + + list_for_each_entry(dtc, &info->channels, node) { + struct dmatest_thread *thread; + + thread_count = 0; + list_for_each_entry(thread, &dtc->threads, node) { + thread_count++; + } + pr_info("%u threads using %s\n", + thread_count, dma_chan_name(dtc->chan)); + } + + return 0; +} + static int __init dmatest_init(void) { struct dmatest_info *info = &test_info; @@ -1074,7 +1231,8 @@ 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); }