test_firmware: add batched firmware tests

The firmware API has a feature to enable batching requests for the same fil
e under one worker, so only one lookup is done. This only triggers if we so
happen to schedule two lookups for same file around the same time, or if
release_firmware() has not been called for a successful firmware call. This
can happen for instance if you happen to have multiple devices and one
device driver for certain drivers where the stars line up scheduling
wise.

This adds a new sync and async test trigger. Instead of adding a new
trigger for each new test type we make the tests a bit configurable so that
we could configure the tests in userspace and just kick a test through a
few basic triggers. With this, for instance the two types of sync requests:

  o request_firmware() and
  o request_firmware_direct()

can be modified with a knob. Likewise the two type of async requests:

   o request_firmware_nowait(uevent=true) and
   o request_firmware_nowait(uevent=false)

can be configured with another knob. The call request_firmware_into_buf()
has no users... yet.

The old tests are left in place as-is given they serve a few other purposes
which we are currently not interested in also testing yet. This will change
later as we will be able to just consolidate all tests under a few basic
triggers with just one general configuration setup.

We perform two types of tests, one for where the file is present and one
for where the file is not present. All test tests go tested and they now
pass for the following 3 kernel builds possible for the firmware API:

0. Most distro setup:
   CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
   CONFIG_FW_LOADER_USER_HELPER=y
1. Android:
   CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y
   CONFIG_FW_LOADER_USER_HELPER=y
2. Rare build:
   CONFIG_FW_LOADER_USER_HELPER_FALLBACK=n
   CONFIG_FW_LOADER_USER_HELPER=n
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lib/test_firmware.c

@@ -19,10 +19,85 @@
 #include <linux/miscdevice.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+
+#define TEST_FIRMWARE_NAME	"test-firmware.bin"
+#define TEST_FIRMWARE_NUM_REQS	4
 
 static DEFINE_MUTEX(test_fw_mutex);
 static const struct firmware *test_firmware;
 
+struct test_batched_req {
+	u8 idx;
+	int rc;
+	bool sent;
+	const struct firmware *fw;
+	const char *name;
+	struct completion completion;
+	struct task_struct *task;
+	struct device *dev;
+};
+
+/**
+ * test_config - represents configuration for the test for different triggers
+ *
+ * @name: the name of the firmware file to look for
+ * @sync_direct: when the sync trigger is used if this is true
+ *	request_firmware_direct() will be used instead.
+ * @send_uevent: whether or not to send a uevent for async requests
+ * @num_requests: number of requests to try per test case. This is trigger
+ *	specific.
+ * @reqs: stores all requests information
+ * @read_fw_idx: index of thread from which we want to read firmware results
+ *	from through the read_fw trigger.
+ * @test_result: a test may use this to collect the result from the call
+ *	of the request_firmware*() calls used in their tests. In order of
+ *	priority we always keep first any setup error. If no setup errors were
+ *	found then we move on to the first error encountered while running the
+ *	API. Note that for async calls this typically will be a successful
+ *	result (0) unless of course you've used bogus parameters, or the system
+ *	is out of memory.  In the async case the callback is expected to do a
+ *	bit more homework to figure out what happened, unfortunately the only
+ *	information passed today on error is the fact that no firmware was
+ *	found so we can only assume -ENOENT on async calls if the firmware is
+ *	NULL.
+ *
+ *	Errors you can expect:
+ *
+ *	API specific:
+ *
+ *	0:		success for sync, for async it means request was sent
+ *	-EINVAL:	invalid parameters or request
+ *	-ENOENT:	files not found
+ *
+ *	System environment:
+ *
+ *	-ENOMEM:	memory pressure on system
+ *	-ENODEV:	out of number of devices to test
+ *	-EINVAL:	an unexpected error has occurred
+ * @req_firmware: if @sync_direct is true this is set to
+ *	request_firmware_direct(), otherwise request_firmware()
+ */
+struct test_config {
+	char *name;
+	bool sync_direct;
+	bool send_uevent;
+	u8 num_requests;
+	u8 read_fw_idx;
+
+	/*
+	 * These below don't belong her but we'll move them once we create
+	 * a struct fw_test_device and stuff the misc_dev under there later.
+	 */
+	struct test_batched_req *reqs;
+	int test_result;
+	int (*req_firmware)(const struct firmware **fw, const char *name,
+			    struct device *device);
+};
+
+struct test_config *test_fw_config;
+
 static ssize_t test_fw_misc_read(struct file *f, char __user *buf,
 				 size_t size, loff_t *offset)
 {
@@ -42,6 +117,338 @@ static const struct file_operations test_fw_fops = {
 	.read           = test_fw_misc_read,
 };
 
+static void __test_release_all_firmware(void)
+{
+	struct test_batched_req *req;
+	u8 i;
+
+	if (!test_fw_config->reqs)
+		return;
+
+	for (i = 0; i < test_fw_config->num_requests; i++) {
+		req = &test_fw_config->reqs[i];
+		if (req->fw)
+			release_firmware(req->fw);
+	}
+
+	vfree(test_fw_config->reqs);
+	test_fw_config->reqs = NULL;
+}
+
+static void test_release_all_firmware(void)
+{
+	mutex_lock(&test_fw_mutex);
+	__test_release_all_firmware();
+	mutex_unlock(&test_fw_mutex);
+}
+
+
+static void __test_firmware_config_free(void)
+{
+	__test_release_all_firmware();
+	kfree_const(test_fw_config->name);
+	test_fw_config->name = NULL;
+}
+
+/*
+ * XXX: move to kstrncpy() once merged.
+ *
+ * Users should use kfree_const() when freeing these.
+ */
+static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp)
+{
+	*dst = kstrndup(name, count, gfp);
+	if (!*dst)
+		return -ENOSPC;
+	return count;
+}
+
+static int __test_firmware_config_init(void)
+{
+	int ret;
+
+	ret = __kstrncpy(&test_fw_config->name, TEST_FIRMWARE_NAME,
+			 strlen(TEST_FIRMWARE_NAME), GFP_KERNEL);
+	if (ret < 0)
+		goto out;
+
+	test_fw_config->num_requests = TEST_FIRMWARE_NUM_REQS;
+	test_fw_config->send_uevent = true;
+	test_fw_config->sync_direct = false;
+	test_fw_config->req_firmware = request_firmware;
+	test_fw_config->test_result = 0;
+	test_fw_config->reqs = NULL;
+
+	return 0;
+
+out:
+	__test_firmware_config_free();
+	return ret;
+}
+
+static ssize_t reset_store(struct device *dev,
+			   struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	int ret;
+
+	mutex_lock(&test_fw_mutex);
+
+	__test_firmware_config_free();
+
+	ret = __test_firmware_config_init();
+	if (ret < 0) {
+		ret = -ENOMEM;
+		pr_err("could not alloc settings for config trigger: %d\n",
+		       ret);
+		goto out;
+	}
+
+	pr_info("reset\n");
+	ret = count;
+
+out:
+	mutex_unlock(&test_fw_mutex);
+
+	return ret;
+}
+static DEVICE_ATTR_WO(reset);
+
+static ssize_t config_show(struct device *dev,
+			   struct device_attribute *attr,
+			   char *buf)
+{
+	int len = 0;
+
+	mutex_lock(&test_fw_mutex);
+
+	len += snprintf(buf, PAGE_SIZE,
+			"Custom trigger configuration for: %s\n",
+			dev_name(dev));
+
+	if (test_fw_config->name)
+		len += snprintf(buf+len, PAGE_SIZE,
+				"name:\t%s\n",
+				test_fw_config->name);
+	else
+		len += snprintf(buf+len, PAGE_SIZE,
+				"name:\tEMTPY\n");
+
+	len += snprintf(buf+len, PAGE_SIZE,
+			"num_requests:\t%u\n", test_fw_config->num_requests);
+
+	len += snprintf(buf+len, PAGE_SIZE,
+			"send_uevent:\t\t%s\n",
+			test_fw_config->send_uevent ?
+			"FW_ACTION_HOTPLUG" :
+			"FW_ACTION_NOHOTPLUG");
+	len += snprintf(buf+len, PAGE_SIZE,
+			"sync_direct:\t\t%s\n",
+			test_fw_config->sync_direct ? "true" : "false");
+	len += snprintf(buf+len, PAGE_SIZE,
+			"read_fw_idx:\t%u\n", test_fw_config->read_fw_idx);
+
+	mutex_unlock(&test_fw_mutex);
+
+	return len;
+}
+static DEVICE_ATTR_RO(config);
+
+static ssize_t config_name_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	int ret;
+
+	mutex_lock(&test_fw_mutex);
+	kfree_const(test_fw_config->name);
+	ret = __kstrncpy(&test_fw_config->name, buf, count, GFP_KERNEL);
+	mutex_unlock(&test_fw_mutex);
+
+	return ret;
+}
+
+/*
+ * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE.
+ */
+static ssize_t config_test_show_str(char *dst,
+				    char *src)
+{
+	int len;
+
+	mutex_lock(&test_fw_mutex);
+	len = snprintf(dst, PAGE_SIZE, "%s\n", src);
+	mutex_unlock(&test_fw_mutex);
+
+	return len;
+}
+
+static int test_dev_config_update_bool(const char *buf, size_t size,
+				       bool *cfg)
+{
+	int ret;
+
+	mutex_lock(&test_fw_mutex);
+	if (strtobool(buf, cfg) < 0)
+		ret = -EINVAL;
+	else
+		ret = size;
+	mutex_unlock(&test_fw_mutex);
+
+	return ret;
+}
+
+static ssize_t
+test_dev_config_show_bool(char *buf,
+			  bool config)
+{
+	bool val;
+
+	mutex_lock(&test_fw_mutex);
+	val = config;
+	mutex_unlock(&test_fw_mutex);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
+static ssize_t test_dev_config_show_int(char *buf, int cfg)
+{
+	int val;
+
+	mutex_lock(&test_fw_mutex);
+	val = cfg;
+	mutex_unlock(&test_fw_mutex);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
+static int test_dev_config_update_u8(const char *buf, size_t size, u8 *cfg)
+{
+	int ret;
+	long new;
+
+	ret = kstrtol(buf, 10, &new);
+	if (ret)
+		return ret;
+
+	if (new > U8_MAX)
+		return -EINVAL;
+
+	mutex_lock(&test_fw_mutex);
+	*(u8 *)cfg = new;
+	mutex_unlock(&test_fw_mutex);
+
+	/* Always return full write size even if we didn't consume all */
+	return size;
+}
+
+static ssize_t test_dev_config_show_u8(char *buf, u8 cfg)
+{
+	u8 val;
+
+	mutex_lock(&test_fw_mutex);
+	val = cfg;
+	mutex_unlock(&test_fw_mutex);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", val);
+}
+
+static ssize_t config_name_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	return config_test_show_str(buf, test_fw_config->name);
+}
+static DEVICE_ATTR(config_name, 0644, config_name_show, config_name_store);
+
+static ssize_t config_num_requests_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	int rc;
+
+	mutex_lock(&test_fw_mutex);
+	if (test_fw_config->reqs) {
+		pr_err("Must call release_all_firmware prior to changing config\n");
+		rc = -EINVAL;
+		goto out;
+	}
+	mutex_unlock(&test_fw_mutex);
+
+	rc = test_dev_config_update_u8(buf, count,
+				       &test_fw_config->num_requests);
+
+out:
+	return rc;
+}
+
+static ssize_t config_num_requests_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	return test_dev_config_show_u8(buf, test_fw_config->num_requests);
+}
+static DEVICE_ATTR(config_num_requests, 0644, config_num_requests_show,
+		   config_num_requests_store);
+
+static ssize_t config_sync_direct_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	int rc = test_dev_config_update_bool(buf, count,
+					     &test_fw_config->sync_direct);
+
+	if (rc == count)
+		test_fw_config->req_firmware = test_fw_config->sync_direct ?
+				       request_firmware_direct :
+				       request_firmware;
+	return rc;
+}
+
+static ssize_t config_sync_direct_show(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	return test_dev_config_show_bool(buf, test_fw_config->sync_direct);
+}
+static DEVICE_ATTR(config_sync_direct, 0644, config_sync_direct_show,
+		   config_sync_direct_store);
+
+static ssize_t config_send_uevent_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	return test_dev_config_update_bool(buf, count,
+					   &test_fw_config->send_uevent);
+}
+
+static ssize_t config_send_uevent_show(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	return test_dev_config_show_bool(buf, test_fw_config->send_uevent);
+}
+static DEVICE_ATTR(config_send_uevent, 0644, config_send_uevent_show,
+		   config_send_uevent_store);
+
+static ssize_t config_read_fw_idx_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	return test_dev_config_update_u8(buf, count,
+					 &test_fw_config->read_fw_idx);
+}
+
+static ssize_t config_read_fw_idx_show(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	return test_dev_config_show_u8(buf, test_fw_config->read_fw_idx);
+}
+static DEVICE_ATTR(config_read_fw_idx, 0644, config_read_fw_idx_show,
+		   config_read_fw_idx_store);
+
+
 static ssize_t trigger_request_store(struct device *dev,
 				     struct device_attribute *attr,
 				     const char *buf, size_t count)
@@ -170,12 +577,301 @@ static ssize_t trigger_custom_fallback_store(struct device *dev,
 }
 static DEVICE_ATTR_WO(trigger_custom_fallback);
 
+static int test_fw_run_batch_request(void *data)
+{
+	struct test_batched_req *req = data;
+
+	if (!req) {
+		test_fw_config->test_result = -EINVAL;
+		return -EINVAL;
+	}
+
+	req->rc = test_fw_config->req_firmware(&req->fw, req->name, req->dev);
+	if (req->rc) {
+		pr_info("#%u: batched sync load failed: %d\n",
+			req->idx, req->rc);
+		if (!test_fw_config->test_result)
+			test_fw_config->test_result = req->rc;
+	} else if (req->fw) {
+		req->sent = true;
+		pr_info("#%u: batched sync loaded %zu\n",
+			req->idx, req->fw->size);
+	}
+	complete(&req->completion);
+
+	req->task = NULL;
+
+	return 0;
+}
+
+/*
+ * We use a kthread as otherwise the kernel serializes all our sync requests
+ * and we would not be able to mimic batched requests on a sync call. Batched
+ * requests on a sync call can for instance happen on a device driver when
+ * multiple cards are used and firmware loading happens outside of probe.
+ */
+static ssize_t trigger_batched_requests_store(struct device *dev,
+					      struct device_attribute *attr,
+					      const char *buf, size_t count)
+{
+	struct test_batched_req *req;
+	int rc;
+	u8 i;
+
+	mutex_lock(&test_fw_mutex);
+
+	test_fw_config->reqs = vzalloc(sizeof(struct test_batched_req) *
+				       test_fw_config->num_requests * 2);
+	if (!test_fw_config->reqs) {
+		rc = -ENOMEM;
+		goto out_unlock;
+	}
+
+	pr_info("batched sync firmware loading '%s' %u times\n",
+		test_fw_config->name, test_fw_config->num_requests);
+
+	for (i = 0; i < test_fw_config->num_requests; i++) {
+		req = &test_fw_config->reqs[i];
+		if (!req) {
+			WARN_ON(1);
+			rc = -ENOMEM;
+			goto out_bail;
+		}
+		req->fw = NULL;
+		req->idx = i;
+		req->name = test_fw_config->name;
+		req->dev = dev;
+		init_completion(&req->completion);
+		req->task = kthread_run(test_fw_run_batch_request, req,
+					     "%s-%u", KBUILD_MODNAME, req->idx);
+		if (!req->task || IS_ERR(req->task)) {
+			pr_err("Setting up thread %u failed\n", req->idx);
+			req->task = NULL;
+			rc = -ENOMEM;
+			goto out_bail;
+		}
+	}
+
+	rc = count;
+
+	/*
+	 * We require an explicit release to enable more time and delay of
+	 * calling release_firmware() to improve our chances of forcing a
+	 * batched request. If we instead called release_firmware() right away
+	 * then we might miss on an opportunity of having a successful firmware
+	 * request pass on the opportunity to be come a batched request.
+	 */
+
+out_bail:
+	for (i = 0; i < test_fw_config->num_requests; i++) {
+		req = &test_fw_config->reqs[i];
+		if (req->task || req->sent)
+			wait_for_completion(&req->completion);
+	}
+
+	/* Override any worker error if we had a general setup error */
+	if (rc < 0)
+		test_fw_config->test_result = rc;
+
+out_unlock:
+	mutex_unlock(&test_fw_mutex);
+
+	return rc;
+}
+static DEVICE_ATTR_WO(trigger_batched_requests);
+
+/*
+ * We wait for each callback to return with the lock held, no need to lock here
+ */
+static void trigger_batched_cb(const struct firmware *fw, void *context)
+{
+	struct test_batched_req *req = context;
+
+	if (!req) {
+		test_fw_config->test_result = -EINVAL;
+		return;
+	}
+
+	/* forces *some* batched requests to queue up */
+	if (!req->idx)
+		ssleep(2);
+
+	req->fw = fw;
+
+	/*
+	 * Unfortunately the firmware API gives us nothing other than a null FW
+	 * if the firmware was not found on async requests.  Best we can do is
+	 * just assume -ENOENT. A better API would pass the actual return
+	 * value to the callback.
+	 */
+	if (!fw && !test_fw_config->test_result)
+		test_fw_config->test_result = -ENOENT;
+
+	complete(&req->completion);
+}
+
+static
+ssize_t trigger_batched_requests_async_store(struct device *dev,
+					     struct device_attribute *attr,
+					     const char *buf, size_t count)
+{
+	struct test_batched_req *req;
+	bool send_uevent;
+	int rc;
+	u8 i;
+
+	mutex_lock(&test_fw_mutex);
+
+	test_fw_config->reqs = vzalloc(sizeof(struct test_batched_req) *
+				       test_fw_config->num_requests * 2);
+	if (!test_fw_config->reqs) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	pr_info("batched loading '%s' custom fallback mechanism %u times\n",
+		test_fw_config->name, test_fw_config->num_requests);
+
+	send_uevent = test_fw_config->send_uevent ? FW_ACTION_HOTPLUG :
+		FW_ACTION_NOHOTPLUG;
+
+	for (i = 0; i < test_fw_config->num_requests; i++) {
+		req = &test_fw_config->reqs[i];
+		if (!req) {
+			WARN_ON(1);
+			goto out_bail;
+		}
+		req->name = test_fw_config->name;
+		req->fw = NULL;
+		req->idx = i;
+		init_completion(&req->completion);
+		rc = request_firmware_nowait(THIS_MODULE, send_uevent,
+					     req->name,
+					     dev, GFP_KERNEL, req,
+					     trigger_batched_cb);
+		if (rc) {
+			pr_info("#%u: batched async load failed setup: %d\n",
+				i, rc);
+			req->rc = rc;
+			goto out_bail;
+		} else
+			req->sent = true;
+	}
+
+	rc = count;
+
+out_bail:
+
+	/*
+	 * We require an explicit release to enable more time and delay of
+	 * calling release_firmware() to improve our chances of forcing a
+	 * batched request. If we instead called release_firmware() right away
+	 * then we might miss on an opportunity of having a successful firmware
+	 * request pass on the opportunity to be come a batched request.
+	 */
+
+	for (i = 0; i < test_fw_config->num_requests; i++) {
+		req = &test_fw_config->reqs[i];
+		if (req->sent)
+			wait_for_completion(&req->completion);
+	}
+
+	/* Override any worker error if we had a general setup error */
+	if (rc < 0)
+		test_fw_config->test_result = rc;
+
+out:
+	mutex_unlock(&test_fw_mutex);
+
+	return rc;
+}
+static DEVICE_ATTR_WO(trigger_batched_requests_async);
+
+static ssize_t test_result_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	return test_dev_config_show_int(buf, test_fw_config->test_result);
+}
+static DEVICE_ATTR_RO(test_result);
+
+static ssize_t release_all_firmware_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t count)
+{
+	test_release_all_firmware();
+	return count;
+}
+static DEVICE_ATTR_WO(release_all_firmware);
+
+static ssize_t read_firmware_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct test_batched_req *req;
+	u8 idx;
+	ssize_t rc = 0;
+
+	mutex_lock(&test_fw_mutex);
+
+	idx = test_fw_config->read_fw_idx;
+	if (idx >= test_fw_config->num_requests) {
+		rc = -ERANGE;
+		goto out;
+	}
+
+	if (!test_fw_config->reqs) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	req = &test_fw_config->reqs[idx];
+	if (!req->fw) {
+		pr_err("#%u: failed to async load firmware\n", idx);
+		rc = -ENOENT;
+		goto out;
+	}
+
+	pr_info("#%u: loaded %zu\n", idx, req->fw->size);
+
+	if (req->fw->size > PAGE_SIZE) {
+		pr_err("Testing interface must use PAGE_SIZE firmware for now\n");
+		rc = -EINVAL;
+	}
+	memcpy(buf, req->fw->data, req->fw->size);
+
+	rc = req->fw->size;
+out:
+	mutex_unlock(&test_fw_mutex);
+
+	return rc;
+}
+static DEVICE_ATTR_RO(read_firmware);
+
 #define TEST_FW_DEV_ATTR(name)          &dev_attr_##name.attr
 
 static struct attribute *test_dev_attrs[] = {
+	TEST_FW_DEV_ATTR(reset),
+
+	TEST_FW_DEV_ATTR(config),
+	TEST_FW_DEV_ATTR(config_name),
+	TEST_FW_DEV_ATTR(config_num_requests),
+	TEST_FW_DEV_ATTR(config_sync_direct),
+	TEST_FW_DEV_ATTR(config_send_uevent),
+	TEST_FW_DEV_ATTR(config_read_fw_idx),
+
+	/* These don't use the config at all - they could be ported! */
 	TEST_FW_DEV_ATTR(trigger_request),
 	TEST_FW_DEV_ATTR(trigger_async_request),
 	TEST_FW_DEV_ATTR(trigger_custom_fallback),
+
+	/* These use the config and can use the test_result */
+	TEST_FW_DEV_ATTR(trigger_batched_requests),
+	TEST_FW_DEV_ATTR(trigger_batched_requests_async),
+
+	TEST_FW_DEV_ATTR(release_all_firmware),
+	TEST_FW_DEV_ATTR(test_result),
+	TEST_FW_DEV_ATTR(read_firmware),
 	NULL,
 };
 
@@ -192,8 +888,17 @@ static int __init test_firmware_init(void)
 {
 	int rc;
 
+	test_fw_config = kzalloc(sizeof(struct test_config), GFP_KERNEL);
+	if (!test_fw_config)
+		return -ENOMEM;
+
+	rc = __test_firmware_config_init();
+	if (rc)
+		return rc;
+
 	rc = misc_register(&test_fw_misc_device);
 	if (rc) {
+		kfree(test_fw_config);
 		pr_err("could not register misc device: %d\n", rc);
 		return rc;
 	}
@@ -207,8 +912,13 @@ module_init(test_firmware_init);
 
 static void __exit test_firmware_exit(void)
 {
+	mutex_lock(&test_fw_mutex);
 	release_firmware(test_firmware);
 	misc_deregister(&test_fw_misc_device);
+	__test_firmware_config_free();
+	kfree(test_fw_config);
+	mutex_unlock(&test_fw_mutex);
+
 	pr_warn("removed interface\n");
 }
 

tools/testing/selftests/firmware/fw_filesystem.sh

@@ -25,8 +25,9 @@ if [ ! -d $DIR ]; then
 fi
 
 # CONFIG_FW_LOADER_USER_HELPER has a sysfs class under /sys/class/firmware/
-# These days no one enables CONFIG_FW_LOADER_USER_HELPER so check for that
-# as an indicator for CONFIG_FW_LOADER_USER_HELPER.
+# These days most distros enable CONFIG_FW_LOADER_USER_HELPER but disable
+# CONFIG_FW_LOADER_USER_HELPER_FALLBACK. We use /sys/class/firmware/ as an
+# indicator for CONFIG_FW_LOADER_USER_HELPER.
 HAS_FW_LOADER_USER_HELPER=$(if [ -d /sys/class/firmware/ ]; then echo yes; else echo no; fi)
 
 if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
@@ -116,4 +117,240 @@ else
 	echo "$0: async filesystem loading works"
 fi
 
+### Batched requests tests
+test_config_present()
+{
+	if [ ! -f $DIR/reset ]; then
+		echo "Configuration triggers not present, ignoring test"
+		exit 0
+	fi
+}
+
+# Defaults :
+#
+# send_uevent: 1
+# sync_direct: 0
+# name: test-firmware.bin
+# num_requests: 4
+config_reset()
+{
+	echo 1 >  $DIR/reset
+}
+
+release_all_firmware()
+{
+	echo 1 >  $DIR/release_all_firmware
+}
+
+config_set_name()
+{
+	echo -n $1 >  $DIR/config_name
+}
+
+config_set_sync_direct()
+{
+	echo 1 >  $DIR/config_sync_direct
+}
+
+config_unset_sync_direct()
+{
+	echo 0 >  $DIR/config_sync_direct
+}
+
+config_set_uevent()
+{
+	echo 1 >  $DIR/config_send_uevent
+}
+
+config_unset_uevent()
+{
+	echo 0 >  $DIR/config_send_uevent
+}
+
+config_trigger_sync()
+{
+	echo -n 1 > $DIR/trigger_batched_requests 2>/dev/null
+}
+
+config_trigger_async()
+{
+	echo -n 1 > $DIR/trigger_batched_requests_async 2> /dev/null
+}
+
+config_set_read_fw_idx()
+{
+	echo -n $1 > $DIR/config_read_fw_idx 2> /dev/null
+}
+
+read_firmwares()
+{
+	for i in $(seq 0 3); do
+		config_set_read_fw_idx $i
+		# Verify the contents are what we expect.
+		# -Z required for now -- check for yourself, md5sum
+		# on $FW and DIR/read_firmware will yield the same. Even
+		# cmp agrees, so something is off.
+		if ! diff -q -Z "$FW" $DIR/read_firmware 2>/dev/null ; then
+			echo "request #$i: firmware was not loaded" >&2
+			exit 1
+		fi
+	done
+}
+
+read_firmwares_expect_nofile()
+{
+	for i in $(seq 0 3); do
+		config_set_read_fw_idx $i
+		# Ensures contents differ
+		if diff -q -Z "$FW" $DIR/read_firmware 2>/dev/null ; then
+			echo "request $i: file was not expected to match" >&2
+			exit 1
+		fi
+	done
+}
+
+test_batched_request_firmware_nofile()
+{
+	echo -n "Batched request_firmware() nofile try #$1: "
+	config_reset
+	config_set_name nope-test-firmware.bin
+	config_trigger_sync
+	read_firmwares_expect_nofile
+	release_all_firmware
+	echo "OK"
+}
+
+test_batched_request_firmware_direct_nofile()
+{
+	echo -n "Batched request_firmware_direct() nofile try #$1: "
+	config_reset
+	config_set_name nope-test-firmware.bin
+	config_set_sync_direct
+	config_trigger_sync
+	release_all_firmware
+	echo "OK"
+}
+
+test_request_firmware_nowait_uevent_nofile()
+{
+	echo -n "Batched request_firmware_nowait(uevent=true) nofile try #$1: "
+	config_reset
+	config_set_name nope-test-firmware.bin
+	config_trigger_async
+	release_all_firmware
+	echo "OK"
+}
+
+test_wait_and_cancel_custom_load()
+{
+	if [ "$HAS_FW_LOADER_USER_HELPER" != "yes" ]; then
+		return
+	fi
+	local timeout=10
+	name=$1
+	while [ ! -e "$DIR"/"$name"/loading ]; do
+		sleep 0.1
+		timeout=$(( $timeout - 1 ))
+		if [ "$timeout" -eq 0 ]; then
+			echo "firmware interface never appeared:" >&2
+			echo "$DIR/$name/loading" >&2
+			exit 1
+		fi
+	done
+	echo -1 >"$DIR"/"$name"/loading
+}
+
+test_request_firmware_nowait_custom_nofile()
+{
+	echo -n "Batched request_firmware_nowait(uevent=false) nofile try #$1: "
+	config_unset_uevent
+	config_set_name nope-test-firmware.bin
+	config_trigger_async &
+	test_wait_and_cancel_custom_load nope-test-firmware.bin
+	wait
+	release_all_firmware
+	echo "OK"
+}
+
+test_batched_request_firmware()
+{
+	echo -n "Batched request_firmware() try #$1: "
+	config_reset
+	config_trigger_sync
+	read_firmwares
+	release_all_firmware
+	echo "OK"
+}
+
+test_batched_request_firmware_direct()
+{
+	echo -n "Batched request_firmware_direct() try #$1: "
+	config_reset
+	config_set_sync_direct
+	config_trigger_sync
+	release_all_firmware
+	echo "OK"
+}
+
+test_request_firmware_nowait_uevent()
+{
+	echo -n "Batched request_firmware_nowait(uevent=true) try #$1: "
+	config_reset
+	config_trigger_async
+	release_all_firmware
+	echo "OK"
+}
+
+test_request_firmware_nowait_custom()
+{
+	echo -n "Batched request_firmware_nowait(uevent=false) try #$1: "
+	config_unset_uevent
+	config_trigger_async
+	release_all_firmware
+	echo "OK"
+}
+
+# Only continue if batched request triggers are present on the
+# test-firmware driver
+test_config_present
+
+# test with the file present
+echo
+echo "Testing with the file present..."
+for i in $(seq 1 5); do
+	test_batched_request_firmware $i
+done
+
+for i in $(seq 1 5); do
+	test_batched_request_firmware_direct $i
+done
+
+for i in $(seq 1 5); do
+	test_request_firmware_nowait_uevent $i
+done
+
+for i in $(seq 1 5); do
+	test_request_firmware_nowait_custom $i
+done
+
+# Test for file not found, errors are expected, the failure would be
+# a hung task, which would require a hard reset.
+echo
+echo "Testing with the file missing..."
+for i in $(seq 1 5); do
+	test_batched_request_firmware_nofile $i
+done
+
+for i in $(seq 1 5); do
+	test_batched_request_firmware_direct_nofile $i
+done
+
+for i in $(seq 1 5); do
+	test_request_firmware_nowait_uevent_nofile $i
+done
+
+for i in $(seq 1 5); do
+	test_request_firmware_nowait_custom_nofile $i
+done
+
 exit 0