diff options
| -rw-r--r-- | Documentation/dmatest.txt | 48 | ||||
| -rw-r--r-- | drivers/dma/dmatest.c | 257 |
2 files changed, 303 insertions, 2 deletions
diff --git a/Documentation/dmatest.txt b/Documentation/dmatest.txt new file mode 100644 index 0000000..9a90729 --- /dev/null +++ b/Documentation/dmatest.txt @@ -0,0 +1,48 @@ + DMA Test Guide + ============== + + Andy Shevchenko <andriy.shevchenko@linux.intel.com> + +This small document introduces how to test DMA drivers using dmatest module. + + Part 1 - How to build the test module + +The menuconfig contains an option that could be found by following path: + Device Drivers -> DMA Engine support -> DMA Test client + +In the configuration file the option called CONFIG_DMATEST. The dmatest could +be built as module or inside kernel. Let's consider those cases. + + Part 2 - When dmatest is built as a module... + +After mounting debugfs and loading the module, the /sys/kernel/debug/dmatest +folder with nodes will be created. They are the same as module parameters with +addition of the 'run' node that controls run and stop phases of the test. + +Note that in this case test will not run on load automatically. + +Example of usage: + % echo dma0chan0 > /sys/kernel/debug/dmatest/channel + % echo 2000 > /sys/kernel/debug/dmatest/timeout + % echo 1 > /sys/kernel/debug/dmatest/iterations + % echo 1 > /sys/kernel/debug/dmatest/run + +Hint: available channel list could be extracted by running the following +command: + % ls -1 /sys/class/dma/ + +After a while you will start to get messages about current status or error like +in the original code. + +Note that running a new test will stop any in progress test. + + Part 3 - When built-in in the kernel... + +The module parameters that is supplied to the kernel command line will be used +for the first performed test. After user gets a control, the test could be +interrupted or re-run with same or different parameters. For the details see +the above section "Part 2 - When dmatest is built as a module..." + +In both cases the module parameters are used as initial values for the test case. +You always could check them at run-time by running + % grep -H . /sys/module/dmatest/parameters/* diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index c6e5d83..fc31542 100644 --- a/drivers/dma/dmatest.c +++ b/drivers/dma/dmatest.c @@ -2,6 +2,7 @@ * DMA Engine test module * * Copyright (C) 2007 Atmel Corporation + * Copyright (C) 2013 Intel Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -18,6 +19,10 @@ #include <linux/random.h> #include <linux/slab.h> #include <linux/wait.h> +#include <linux/ctype.h> +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/seq_file.h> static unsigned int test_buf_size = 16384; module_param(test_buf_size, uint, S_IRUGO); @@ -123,6 +128,7 @@ struct dmatest_params { /** * struct dmatest_info - test information. * @params: test parameters + * @lock: access protection to the fields of this structure */ struct dmatest_info { /* Test parameters */ @@ -131,6 +137,11 @@ struct dmatest_info { /* Internal state */ struct list_head channels; unsigned int nr_channels; + struct mutex lock; + + /* debugfs related stuff */ + struct dentry *root; + struct dmatest_params dbgfs_params; }; static struct dmatest_info test_info; @@ -718,7 +729,7 @@ static bool filter(struct dma_chan *chan, void *param) return true; } -static int run_threaded_test(struct dmatest_info *info) +static int __run_threaded_test(struct dmatest_info *info) { dma_cap_mask_t mask; struct dma_chan *chan; @@ -744,7 +755,19 @@ static int run_threaded_test(struct dmatest_info *info) return err; } -static void stop_threaded_test(struct dmatest_info *info) +#ifndef MODULE +static int run_threaded_test(struct dmatest_info *info) +{ + int ret; + + mutex_lock(&info->lock); + ret = __run_threaded_test(info); + mutex_unlock(&info->lock); + return ret; +} +#endif + +static void __stop_threaded_test(struct dmatest_info *info) { struct dmatest_chan *dtc, *_dtc; struct dma_chan *chan; @@ -760,13 +783,234 @@ static void stop_threaded_test(struct dmatest_info *info) info->nr_channels = 0; } +static void stop_threaded_test(struct dmatest_info *info) +{ + mutex_lock(&info->lock); + __stop_threaded_test(info); + mutex_unlock(&info->lock); +} + +static int __restart_threaded_test(struct dmatest_info *info, bool run) +{ + struct dmatest_params *params = &info->params; + int ret; + + /* Stop any running test first */ + __stop_threaded_test(info); + + if (run == false) + return 0; + + /* Copy test parameters */ + memcpy(params, &info->dbgfs_params, sizeof(*params)); + + /* Run test with new parameters */ + ret = __run_threaded_test(info); + if (ret) { + __stop_threaded_test(info); + pr_err("dmatest: Can't run test\n"); + } + + return ret; +} + +static ssize_t dtf_write_string(void *to, size_t available, loff_t *ppos, + const void __user *from, size_t count) +{ + char tmp[20]; + ssize_t len; + + len = simple_write_to_buffer(tmp, sizeof(tmp) - 1, ppos, from, count); + if (len >= 0) { + tmp[len] = '\0'; + strlcpy(to, strim(tmp), available); + } + + return len; +} + +static ssize_t dtf_read_channel(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct dmatest_info *info = file->private_data; + return simple_read_from_buffer(buf, count, ppos, + info->dbgfs_params.channel, + strlen(info->dbgfs_params.channel)); +} + +static ssize_t dtf_write_channel(struct file *file, const char __user *buf, + size_t size, loff_t *ppos) +{ + struct dmatest_info *info = file->private_data; + return dtf_write_string(info->dbgfs_params.channel, + sizeof(info->dbgfs_params.channel), + ppos, buf, size); +} + +static const struct file_operations dtf_channel_fops = { + .read = dtf_read_channel, + .write = dtf_write_channel, + .open = simple_open, + .llseek = default_llseek, +}; + +static ssize_t dtf_read_device(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct dmatest_info *info = file->private_data; + return simple_read_from_buffer(buf, count, ppos, + info->dbgfs_params.device, + strlen(info->dbgfs_params.device)); +} + +static ssize_t dtf_write_device(struct file *file, const char __user *buf, + size_t size, loff_t *ppos) +{ + struct dmatest_info *info = file->private_data; + return dtf_write_string(info->dbgfs_params.device, + sizeof(info->dbgfs_params.device), + ppos, buf, size); +} + +static const struct file_operations dtf_device_fops = { + .read = dtf_read_device, + .write = dtf_write_device, + .open = simple_open, + .llseek = default_llseek, +}; + +static ssize_t dtf_read_run(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct dmatest_info *info = file->private_data; + char buf[3]; + + mutex_lock(&info->lock); + if (info->nr_channels) + buf[0] = 'Y'; + else + buf[0] = 'N'; + mutex_unlock(&info->lock); + buf[1] = '\n'; + buf[2] = 0x00; + return simple_read_from_buffer(user_buf, count, ppos, buf, 2); +} + +static ssize_t dtf_write_run(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct dmatest_info *info = file->private_data; + char buf[16]; + bool bv; + int ret = 0; + + if (copy_from_user(buf, user_buf, min(count, (sizeof(buf) - 1)))) + return -EFAULT; + + if (strtobool(buf, &bv) == 0) { + mutex_lock(&info->lock); + ret = __restart_threaded_test(info, bv); + mutex_unlock(&info->lock); + } + + return ret ? ret : count; +} + +static const struct file_operations dtf_run_fops = { + .read = dtf_read_run, + .write = dtf_write_run, + .open = simple_open, + .llseek = default_llseek, +}; + +static int dmatest_register_dbgfs(struct dmatest_info *info) +{ + struct dentry *d; + struct dmatest_params *params = &info->dbgfs_params; + int ret = -ENOMEM; + + d = debugfs_create_dir("dmatest", NULL); + if (IS_ERR(d)) + return PTR_ERR(d); + if (!d) + goto err_root; + + info->root = d; + + /* Copy initial values */ + memcpy(params, &info->params, sizeof(*params)); + + /* Test parameters */ + + d = debugfs_create_u32("test_buf_size", S_IWUSR | S_IRUGO, info->root, + (u32 *)¶ms->buf_size); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + d = debugfs_create_file("channel", S_IRUGO | S_IWUSR, info->root, + info, &dtf_channel_fops); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + d = debugfs_create_file("device", S_IRUGO | S_IWUSR, info->root, + info, &dtf_device_fops); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + d = debugfs_create_u32("threads_per_chan", S_IWUSR | S_IRUGO, info->root, + (u32 *)¶ms->threads_per_chan); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + d = debugfs_create_u32("max_channels", S_IWUSR | S_IRUGO, info->root, + (u32 *)¶ms->max_channels); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + d = debugfs_create_u32("iterations", S_IWUSR | S_IRUGO, info->root, + (u32 *)¶ms->iterations); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + d = debugfs_create_u32("xor_sources", S_IWUSR | S_IRUGO, info->root, + (u32 *)¶ms->xor_sources); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + d = debugfs_create_u32("pq_sources", S_IWUSR | S_IRUGO, info->root, + (u32 *)¶ms->pq_sources); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + d = debugfs_create_u32("timeout", S_IWUSR | S_IRUGO, info->root, + (u32 *)¶ms->timeout); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + /* Run or stop threaded test */ + d = debugfs_create_file("run", S_IWUSR | S_IRUGO, info->root, + info, &dtf_run_fops); + if (IS_ERR_OR_NULL(d)) + goto err_node; + + return 0; + +err_node: + debugfs_remove_recursive(info->root); +err_root: + pr_err("dmatest: Failed to initialize debugfs\n"); + return ret; +} + static int __init dmatest_init(void) { struct dmatest_info *info = &test_info; struct dmatest_params *params = &info->params; + int ret; memset(info, 0, sizeof(*info)); + mutex_init(&info->lock); INIT_LIST_HEAD(&info->channels); /* Set default parameters */ @@ -780,7 +1024,15 @@ static int __init dmatest_init(void) params->pq_sources = pq_sources; params->timeout = timeout; + ret = dmatest_register_dbgfs(info); + if (ret) + return ret; + +#ifdef MODULE + return 0; +#else return run_threaded_test(info); +#endif } /* when compiled-in wait for drivers to load first */ late_initcall(dmatest_init); @@ -789,6 +1041,7 @@ static void __exit dmatest_exit(void) { struct dmatest_info *info = &test_info; + debugfs_remove_recursive(info->root); stop_threaded_test(info); } module_exit(dmatest_exit); |
