Quelle  test_async_driver_probe.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2014 Google, Inc.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/delay.h>
#include <linux/init.h>
#include <linux/hrtimer.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/time.h>
#include <linux/numa.h>
#include <linux/nodemask.h>
#include <linux/topology.h>

#define TEST_PROBE_DELAY (5 * 1000) /* 5 sec */
#define TEST_PROBE_THRESHOLD (TEST_PROBE_DELAY / 2)

static atomic_t warnings, errors, timeout, async_completed;

static int test_probe(struct platform_device *pdev)
{
 struct device *dev = &pdev->dev;

 /*
 * Determine if we have hit the "timeout" limit for the test if we
 * have then report it as an error, otherwise we wil sleep for the
 * required amount of time and then report completion.
 */
 if (atomic_read(&timeout)) {
  dev_err(dev, "async probe took too long\n");
  atomic_inc(&errors);
 } else {
  dev_dbg(&pdev->dev, "sleeping for %d msecs in probe\n",
    TEST_PROBE_DELAY);
  msleep(TEST_PROBE_DELAY);
  dev_dbg(&pdev->dev, "done sleeping\n");
 }

 /*
 * Report NUMA mismatch if device node is set and we are not
 * performing an async init on that node.
 */
 if (dev->driver->probe_type == PROBE_PREFER_ASYNCHRONOUS) {
  if (IS_ENABLED(CONFIG_NUMA) &&
      dev_to_node(dev) != numa_node_id()) {
   dev_warn(dev, "NUMA node mismatch %d != %d\n",
     dev_to_node(dev), numa_node_id());
   atomic_inc(&warnings);
  }

  atomic_inc(&async_completed);
 }

 return 0;
}

static struct platform_driver async_driver = {
 .driver = {
  .name = "test_async_driver",
  .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 },
 .probe = test_probe,
};

static struct platform_driver sync_driver = {
 .driver = {
  .name = "test_sync_driver",
  .probe_type = PROBE_FORCE_SYNCHRONOUS,
 },
 .probe = test_probe,
};

static struct platform_device *async_dev[NR_CPUS * 2];
static struct platform_device *sync_dev[2];

static struct platform_device *
test_platform_device_register_node(char *name, int id, int nid)
{
 struct platform_device *pdev;
 int ret;

 pdev = platform_device_alloc(name, id);
 if (!pdev)
  return ERR_PTR(-ENOMEM);

 if (nid != NUMA_NO_NODE)
  set_dev_node(&pdev->dev, nid);

 ret = platform_device_add(pdev);
 if (ret) {
  platform_device_put(pdev);
  return ERR_PTR(ret);
 }

 return pdev;

}

static int __init test_async_probe_init(void)
{
 struct platform_device **pdev = NULL;
 int async_id = 0, sync_id = 0;
 unsigned long long duration;
 ktime_t calltime;
 int err, nid, cpu;

 pr_info("registering first set of asynchronous devices...\n");

 for_each_online_cpu(cpu) {
  nid = cpu_to_node(cpu);
  pdev = &async_dev[async_id];
  *pdev = test_platform_device_register_node("test_async_driver",
          async_id,
          nid);
  if (IS_ERR(*pdev)) {
   err = PTR_ERR(*pdev);
   *pdev = NULL;
   pr_err("failed to create async_dev: %d\n", err);
   goto err_unregister_async_devs;
  }

  async_id++;
 }

 pr_info("registering asynchronous driver...\n");
 calltime = ktime_get();
 err = platform_driver_register(&async_driver);
 if (err) {
  pr_err("Failed to register async_driver: %d\n", err);
  goto err_unregister_async_devs;
 }

 duration = (unsigned long long)ktime_ms_delta(ktime_get(), calltime);
 pr_info("registration took %lld msecs\n", duration);
 if (duration > TEST_PROBE_THRESHOLD) {
  pr_err("test failed: probe took too long\n");
  err = -ETIMEDOUT;
  goto err_unregister_async_driver;
 }

 pr_info("registering second set of asynchronous devices...\n");
 calltime = ktime_get();
 for_each_online_cpu(cpu) {
  nid = cpu_to_node(cpu);
  pdev = &async_dev[async_id];

  *pdev = test_platform_device_register_node("test_async_driver",
          async_id,
          nid);
  if (IS_ERR(*pdev)) {
   err = PTR_ERR(*pdev);
   *pdev = NULL;
   pr_err("failed to create async_dev: %d\n", err);
   goto err_unregister_async_driver;
  }

  async_id++;
 }

 duration = (unsigned long long)ktime_ms_delta(ktime_get(), calltime);
 dev_info(&(*pdev)->dev,
   "registration took %lld msecs\n", duration);
 if (duration > TEST_PROBE_THRESHOLD) {
  dev_err(&(*pdev)->dev,
   "test failed: probe took too long\n");
  err = -ETIMEDOUT;
  goto err_unregister_async_driver;
 }


 pr_info("registering first synchronous device...\n");
 nid = cpu_to_node(cpu);
 pdev = &sync_dev[sync_id];

 *pdev = test_platform_device_register_node("test_sync_driver",
         sync_id,
         NUMA_NO_NODE);
 if (IS_ERR(*pdev)) {
  err = PTR_ERR(*pdev);
  *pdev = NULL;
  pr_err("failed to create sync_dev: %d\n", err);
  goto err_unregister_async_driver;
 }

 sync_id++;

 pr_info("registering synchronous driver...\n");
 calltime = ktime_get();
 err = platform_driver_register(&sync_driver);
 if (err) {
  pr_err("Failed to register async_driver: %d\n", err);
  goto err_unregister_sync_devs;
 }

 duration = (unsigned long long)ktime_ms_delta(ktime_get(), calltime);
 pr_info("registration took %lld msecs\n", duration);
 if (duration < TEST_PROBE_THRESHOLD) {
  dev_err(&(*pdev)->dev,
   "test failed: probe was too quick\n");
  err = -ETIMEDOUT;
  goto err_unregister_sync_driver;
 }

 pr_info("registering second synchronous device...\n");
 pdev = &sync_dev[sync_id];
 calltime = ktime_get();

 *pdev = test_platform_device_register_node("test_sync_driver",
         sync_id,
         NUMA_NO_NODE);
 if (IS_ERR(*pdev)) {
  err = PTR_ERR(*pdev);
  *pdev = NULL;
  pr_err("failed to create sync_dev: %d\n", err);
  goto err_unregister_sync_driver;
 }

 sync_id++;

 duration = (unsigned long long)ktime_ms_delta(ktime_get(), calltime);
 dev_info(&(*pdev)->dev,
   "registration took %lld msecs\n", duration);
 if (duration < TEST_PROBE_THRESHOLD) {
  dev_err(&(*pdev)->dev,
   "test failed: probe was too quick\n");
  err = -ETIMEDOUT;
  goto err_unregister_sync_driver;
 }

 /*
 * The async events should have completed while we were taking care
 * of the synchronous events. We will now terminate any outstanding
 * asynchronous probe calls remaining by forcing timeout and remove
 * the driver before we return which should force the flush of the
 * pending asynchronous probe calls.
 *
 * Otherwise if they completed without errors or warnings then
 * report successful completion.
 */
 if (atomic_read(&async_completed) != async_id) {
  pr_err("async events still pending, forcing timeout\n");
  atomic_inc(&timeout);
  err = -ETIMEDOUT;
 } else if (!atomic_read(&errors) && !atomic_read(&warnings)) {
  pr_info("completed successfully\n");
  return 0;
 }

err_unregister_sync_driver:
 platform_driver_unregister(&sync_driver);
err_unregister_sync_devs:
 while (sync_id--)
  platform_device_unregister(sync_dev[sync_id]);
err_unregister_async_driver:
 platform_driver_unregister(&async_driver);
err_unregister_async_devs:
 while (async_id--)
  platform_device_unregister(async_dev[async_id]);

 /*
 * If err is already set then count that as an additional error for
 * the test. Otherwise we will report an invalid argument error and
 * not count that as we should have reached here as a result of
 * errors or warnings being reported by the probe routine.
 */
 if (err)
  atomic_inc(&errors);
 else
  err = -EINVAL;

 pr_err("Test failed with %d errors and %d warnings\n",
        atomic_read(&errors), atomic_read(&warnings));

 return err;
}
module_init(test_async_probe_init);

static void __exit test_async_probe_exit(void)
{
 int id = 2;

 platform_driver_unregister(&async_driver);
 platform_driver_unregister(&sync_driver);

 while (id--)
  platform_device_unregister(sync_dev[id]);

 id = NR_CPUS * 2;
 while (id--)
  platform_device_unregister(async_dev[id]);
}
module_exit(test_async_probe_exit);

MODULE_DESCRIPTION("Test module for asynchronous driver probing");
MODULE_AUTHOR("Dmitry Torokhov ");
MODULE_LICENSE("GPL");