Merge tag 'driver-core-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the "big" set of driver core patches for 4.17-rc1.

  There's really not much here, just a bunch of firmware code
  refactoring from Luis as he attempts to wrangle that codebase into
  something that is managable, along with a bunch of userspace tests for
  it. Other than that, a handful of small bugfixes and reverts of things
  that didn't work out.

  Full details are in the shortlog, it's not all that much.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (30 commits)
  drivers: base: remove check for callback in coredump_store()
  mt7601u: use firmware_request_cache() to address cache on reboot
  firmware: add firmware_request_cache() to help with cache on reboot
  firmware: fix typo on pr_info_once() when ignore_sysfs_fallback is used
  firmware: explicitly include vmalloc.h
  firmware: ensure the firmware cache is not used on incompatible calls
  test_firmware: modify custom fallback tests to use unique files
  firmware: add helper to check to see if fw cache is setup
  firmware: fix checking for return values for fw_add_devm_name()
  rename: _request_firmware_load() fw_load_sysfs_fallback()
  test_firmware: test three firmware kernel configs using a proc knob
  test_firmware: expand on library with shared helpers
  firmware: enable to force disable the fallback mechanism at run time
  firmware: enable run time change of forcing fallback loader
  firmware: move firmware loader into its own directory
  firmware: split firmware fallback functionality into its own file
  firmware: move loading timeout under struct firmware_fallback_config
  firmware: use helpers for setting up a temporary cache timeout
  firmware: simplify CONFIG_FW_LOADER_USER_HELPER_FALLBACK further
  drivers: base: add description for .coredump() callback
  ...

13 files changed, 1006 insertions, 777 deletions

diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 12a7f64d35a9..b074f242a435 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -13,7 +13,7 @@ obj-y			+= power/
 obj-$(CONFIG_HAS_DMA)	+= dma-mapping.o
 obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
 obj-$(CONFIG_ISA_BUS_API)	+= isa.o
-obj-$(CONFIG_FW_LOADER)	+= firmware_class.o
+obj-y				+= firmware_loader/
 obj-$(CONFIG_NUMA)	+= node.o
 obj-$(CONFIG_MEMORY_HOTPLUG_SPARSE) += memory.o
 ifeq ($(CONFIG_SYSFS),y)
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 52ec5174bcb1..e7cb0c6ade81 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -169,11 +169,11 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu)
 }
 
 #ifdef CONFIG_CPU_FREQ
-static cpumask_var_t cpus_to_visit __initdata;
-static void __init parsing_done_workfn(struct work_struct *work);
-static __initdata DECLARE_WORK(parsing_done_work, parsing_done_workfn);
+static cpumask_var_t cpus_to_visit;
+static void parsing_done_workfn(struct work_struct *work);
+static DECLARE_WORK(parsing_done_work, parsing_done_workfn);
 
-static int __init
+static int
 init_cpu_capacity_callback(struct notifier_block *nb,
 			   unsigned long val,
 			   void *data)
@@ -209,7 +209,7 @@ init_cpu_capacity_callback(struct notifier_block *nb,
 	return 0;
 }
 
-static struct notifier_block init_cpu_capacity_notifier __initdata = {
+static struct notifier_block init_cpu_capacity_notifier = {
 	.notifier_call = init_cpu_capacity_callback,
 };
 
@@ -242,7 +242,7 @@ static int __init register_cpufreq_notifier(void)
 }
 core_initcall(register_cpufreq_notifier);
 
-static void __init parsing_done_workfn(struct work_struct *work)
+static void parsing_done_workfn(struct work_struct *work)
 {
 	cpufreq_unregister_notifier(&init_cpu_capacity_notifier,
 					 CPUFREQ_POLICY_NOTIFIER);
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index d21a2d913107..2da998baa75c 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -382,8 +382,10 @@ int register_cpu(struct cpu *cpu, int num)
 	if (cpu->hotpluggable)
 		cpu->dev.groups = hotplugable_cpu_attr_groups;
 	error = device_register(&cpu->dev);
-	if (error)
+	if (error) {
+		put_device(&cpu->dev);
 		return error;
+	}
 
 	per_cpu(cpu_sys_devices, num) = &cpu->dev;
 	register_cpu_under_node(num, cpu_to_node(num));
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index de6fd092bf2f..c9f54089429b 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -292,8 +292,7 @@ static ssize_t coredump_store(struct device *dev, struct device_attribute *attr,
 			    const char *buf, size_t count)
 {
 	device_lock(dev);
-	if (dev->driver->coredump)
-		dev->driver->coredump(dev);
+	dev->driver->coredump(dev);
 	device_unlock(dev);
 
 	return count;
diff --git a/drivers/base/firmware_loader/Makefile b/drivers/base/firmware_loader/Makefile
new file mode 100644
index 000000000000..a97eeb0be1d8
--- /dev/null
+++ b/drivers/base/firmware_loader/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for the Linux firmware loader
+
+obj-y			:= fallback_table.o
+obj-$(CONFIG_FW_LOADER)	+= firmware_class.o
+firmware_class-objs := main.o
+firmware_class-$(CONFIG_FW_LOADER_USER_HELPER) += fallback.o
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
new file mode 100644
index 000000000000..31b5015b59fe
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback.c
@@ -0,0 +1,675 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/types.h>
+#include <linux/kconfig.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/highmem.h>
+#include <linux/umh.h>
+#include <linux/sysctl.h>
+#include <linux/vmalloc.h>
+
+#include "fallback.h"
+#include "firmware.h"
+
+/*
+ * firmware fallback mechanism
+ */
+
+extern struct firmware_fallback_config fw_fallback_config;
+
+/* These getters are vetted to use int properly */
+static inline int __firmware_loading_timeout(void)
+{
+	return fw_fallback_config.loading_timeout;
+}
+
+/* These setters are vetted to use int properly */
+static void __fw_fallback_set_timeout(int timeout)
+{
+	fw_fallback_config.loading_timeout = timeout;
+}
+
+/*
+ * use small loading timeout for caching devices' firmware because all these
+ * firmware images have been loaded successfully at lease once, also system is
+ * ready for completing firmware loading now. The maximum size of firmware in
+ * current distributions is about 2M bytes, so 10 secs should be enough.
+ */
+void fw_fallback_set_cache_timeout(void)
+{
+	fw_fallback_config.old_timeout = __firmware_loading_timeout();
+	__fw_fallback_set_timeout(10);
+}
+
+/* Restores the timeout to the value last configured during normal operation */
+void fw_fallback_set_default_timeout(void)
+{
+	__fw_fallback_set_timeout(fw_fallback_config.old_timeout);
+}
+
+static long firmware_loading_timeout(void)
+{
+	return __firmware_loading_timeout() > 0 ?
+		__firmware_loading_timeout() * HZ : MAX_JIFFY_OFFSET;
+}
+
+static inline bool fw_sysfs_done(struct fw_priv *fw_priv)
+{
+	return __fw_state_check(fw_priv, FW_STATUS_DONE);
+}
+
+static inline bool fw_sysfs_loading(struct fw_priv *fw_priv)
+{
+	return __fw_state_check(fw_priv, FW_STATUS_LOADING);
+}
+
+static inline int fw_sysfs_wait_timeout(struct fw_priv *fw_priv,  long timeout)
+{
+	return __fw_state_wait_common(fw_priv, timeout);
+}
+
+struct fw_sysfs {
+	bool nowait;
+	struct device dev;
+	struct fw_priv *fw_priv;
+	struct firmware *fw;
+};
+
+static struct fw_sysfs *to_fw_sysfs(struct device *dev)
+{
+	return container_of(dev, struct fw_sysfs, dev);
+}
+
+static void __fw_load_abort(struct fw_priv *fw_priv)
+{
+	/*
+	 * There is a small window in which user can write to 'loading'
+	 * between loading done and disappearance of 'loading'
+	 */
+	if (fw_sysfs_done(fw_priv))
+		return;
+
+	list_del_init(&fw_priv->pending_list);
+	fw_state_aborted(fw_priv);
+}
+
+static void fw_load_abort(struct fw_sysfs *fw_sysfs)
+{
+	struct fw_priv *fw_priv = fw_sysfs->fw_priv;
+
+	__fw_load_abort(fw_priv);
+}
+
+static LIST_HEAD(pending_fw_head);
+
+void kill_pending_fw_fallback_reqs(bool only_kill_custom)
+{
+	struct fw_priv *fw_priv;
+	struct fw_priv *next;
+
+	mutex_lock(&fw_lock);
+	list_for_each_entry_safe(fw_priv, next, &pending_fw_head,
+				 pending_list) {
+		if (!fw_priv->need_uevent || !only_kill_custom)
+			 __fw_load_abort(fw_priv);
+	}
+	mutex_unlock(&fw_lock);
+}
+
+static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
+			    char *buf)
+{
+	return sprintf(buf, "%d\n", __firmware_loading_timeout());
+}
+
+/**
+ * firmware_timeout_store - set number of seconds to wait for firmware
+ * @class: device class pointer
+ * @attr: device attribute pointer
+ * @buf: buffer to scan for timeout value
+ * @count: number of bytes in @buf
+ *
+ *	Sets the number of seconds to wait for the firmware.  Once
+ *	this expires an error will be returned to the driver and no
+ *	firmware will be provided.
+ *
+ *	Note: zero means 'wait forever'.
+ **/
+static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
+			     const char *buf, size_t count)
+{
+	int tmp_loading_timeout = simple_strtol(buf, NULL, 10);
+
+	if (tmp_loading_timeout < 0)
+		tmp_loading_timeout = 0;
+
+	__fw_fallback_set_timeout(tmp_loading_timeout);
+
+	return count;
+}
+static CLASS_ATTR_RW(timeout);
+
+static struct attribute *firmware_class_attrs[] = {
+	&class_attr_timeout.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(firmware_class);
+
+static void fw_dev_release(struct device *dev)
+{
+	struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
+
+	kfree(fw_sysfs);
+}
+
+static int do_firmware_uevent(struct fw_sysfs *fw_sysfs, struct kobj_uevent_env *env)
+{
+	if (add_uevent_var(env, "FIRMWARE=%s", fw_sysfs->fw_priv->fw_name))
+		return -ENOMEM;
+	if (add_uevent_var(env, "TIMEOUT=%i", __firmware_loading_timeout()))
+		return -ENOMEM;
+	if (add_uevent_var(env, "ASYNC=%d", fw_sysfs->nowait))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
+	int err = 0;
+
+	mutex_lock(&fw_lock);
+	if (fw_sysfs->fw_priv)
+		err = do_firmware_uevent(fw_sysfs, env);
+	mutex_unlock(&fw_lock);
+	return err;
+}
+
+static struct class firmware_class = {
+	.name		= "firmware",
+	.class_groups	= firmware_class_groups,
+	.dev_uevent	= firmware_uevent,
+	.dev_release	= fw_dev_release,
+};
+
+int register_sysfs_loader(void)
+{
+	return class_register(&firmware_class);
+}
+
+void unregister_sysfs_loader(void)
+{
+	class_unregister(&firmware_class);
+}
+
+static ssize_t firmware_loading_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
+	int loading = 0;
+
+	mutex_lock(&fw_lock);
+	if (fw_sysfs->fw_priv)
+		loading = fw_sysfs_loading(fw_sysfs->fw_priv);
+	mutex_unlock(&fw_lock);
+
+	return sprintf(buf, "%d\n", loading);
+}
+
+/* Some architectures don't have PAGE_KERNEL_RO */
+#ifndef PAGE_KERNEL_RO
+#define PAGE_KERNEL_RO PAGE_KERNEL
+#endif
+
+/* one pages buffer should be mapped/unmapped only once */
+static int map_fw_priv_pages(struct fw_priv *fw_priv)
+{
+	if (!fw_priv->is_paged_buf)
+		return 0;
+
+	vunmap(fw_priv->data);
+	fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
+			     PAGE_KERNEL_RO);
+	if (!fw_priv->data)
+		return -ENOMEM;
+	return 0;
+}
+
+/**
+ * firmware_loading_store - set value in the 'loading' control file
+ * @dev: device pointer
+ * @attr: device attribute pointer
+ * @buf: buffer to scan for loading control value
+ * @count: number of bytes in @buf
+ *
+ *	The relevant values are:
+ *
+ *	 1: Start a load, discarding any previous partial load.
+ *	 0: Conclude the load and hand the data to the driver code.
+ *	-1: Conclude the load with an error and discard any written data.
+ **/
+static ssize_t firmware_loading_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t count)
+{
+	struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
+	struct fw_priv *fw_priv;
+	ssize_t written = count;
+	int loading = simple_strtol(buf, NULL, 10);
+	int i;
+
+	mutex_lock(&fw_lock);
+	fw_priv = fw_sysfs->fw_priv;
+	if (fw_state_is_aborted(fw_priv))
+		goto out;
+
+	switch (loading) {
+	case 1:
+		/* discarding any previous partial load */
+		if (!fw_sysfs_done(fw_priv)) {
+			for (i = 0; i < fw_priv->nr_pages; i++)
+				__free_page(fw_priv->pages[i]);
+			vfree(fw_priv->pages);
+			fw_priv->pages = NULL;
+			fw_priv->page_array_size = 0;
+			fw_priv->nr_pages = 0;
+			fw_state_start(fw_priv);
+		}
+		break;
+	case 0:
+		if (fw_sysfs_loading(fw_priv)) {
+			int rc;
+
+			/*
+			 * Several loading requests may be pending on
+			 * one same firmware buf, so let all requests
+			 * see the mapped 'buf->data' once the loading
+			 * is completed.
+			 * */
+			rc = map_fw_priv_pages(fw_priv);
+			if (rc)
+				dev_err(dev, "%s: map pages failed\n",
+					__func__);
+			else
+				rc = security_kernel_post_read_file(NULL,
+						fw_priv->data, fw_priv->size,
+						READING_FIRMWARE);
+
+			/*
+			 * Same logic as fw_load_abort, only the DONE bit
+			 * is ignored and we set ABORT only on failure.
+			 */
+			list_del_init(&fw_priv->pending_list);
+			if (rc) {
+				fw_state_aborted(fw_priv);
+				written = rc;
+			} else {
+				fw_state_done(fw_priv);
+			}
+			break;
+		}
+		/* fallthrough */
+	default:
+		dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
+		/* fallthrough */
+	case -1:
+		fw_load_abort(fw_sysfs);
+		break;
+	}
+out:
+	mutex_unlock(&fw_lock);
+	return written;
+}
+
+static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
+
+static void firmware_rw_data(struct fw_priv *fw_priv, char *buffer,
+			   loff_t offset, size_t count, bool read)
+{
+	if (read)
+		memcpy(buffer, fw_priv->data + offset, count);
+	else
+		memcpy(fw_priv->data + offset, buffer, count);
+}
+
+static void firmware_rw(struct fw_priv *fw_priv, char *buffer,
+			loff_t offset, size_t count, bool read)
+{
+	while (count) {
+		void *page_data;
+		int page_nr = offset >> PAGE_SHIFT;
+		int page_ofs = offset & (PAGE_SIZE-1);
+		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
+
+		page_data = kmap(fw_priv->pages[page_nr]);
+
+		if (read)
+			memcpy(buffer, page_data + page_ofs, page_cnt);
+		else
+			memcpy(page_data + page_ofs, buffer, page_cnt);
+
+		kunmap(fw_priv->pages[page_nr]);
+		buffer += page_cnt;
+		offset += page_cnt;
+		count -= page_cnt;
+	}
+}
+
+static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
+				  struct bin_attribute *bin_attr,
+				  char *buffer, loff_t offset, size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
+	struct fw_priv *fw_priv;
+	ssize_t ret_count;
+
+	mutex_lock(&fw_lock);
+	fw_priv = fw_sysfs->fw_priv;
+	if (!fw_priv || fw_sysfs_done(fw_priv)) {
+		ret_count = -ENODEV;
+		goto out;
+	}
+	if (offset > fw_priv->size) {
+		ret_count = 0;
+		goto out;
+	}
+	if (count > fw_priv->size - offset)
+		count = fw_priv->size - offset;
+
+	ret_count = count;
+
+	if (fw_priv->data)
+		firmware_rw_data(fw_priv, buffer, offset, count, true);
+	else
+		firmware_rw(fw_priv, buffer, offset, count, true);
+
+out:
+	mutex_unlock(&fw_lock);
+	return ret_count;
+}
+
+static int fw_realloc_pages(struct fw_sysfs *fw_sysfs, int min_size)
+{
+	struct fw_priv *fw_priv= fw_sysfs->fw_priv;
+	int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
+
+	/* If the array of pages is too small, grow it... */
+	if (fw_priv->page_array_size < pages_needed) {
+		int new_array_size = max(pages_needed,
+					 fw_priv->page_array_size * 2);
+		struct page **new_pages;
+
+		new_pages = vmalloc(new_array_size * sizeof(void *));
+		if (!new_pages) {
+			fw_load_abort(fw_sysfs);
+			return -ENOMEM;
+		}
+		memcpy(new_pages, fw_priv->pages,
+		       fw_priv->page_array_size * sizeof(void *));
+		memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
+		       (new_array_size - fw_priv->page_array_size));
+		vfree(fw_priv->pages);
+		fw_priv->pages = new_pages;
+		fw_priv->page_array_size = new_array_size;
+	}
+
+	while (fw_priv->nr_pages < pages_needed) {
+		fw_priv->pages[fw_priv->nr_pages] =
+			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+
+		if (!fw_priv->pages[fw_priv->nr_pages]) {
+			fw_load_abort(fw_sysfs);
+			return -ENOMEM;
+		}
+		fw_priv->nr_pages++;
+	}
+	return 0;
+}
+
+/**
+ * firmware_data_write - write method for firmware
+ * @filp: open sysfs file
+ * @kobj: kobject for the device
+ * @bin_attr: bin_attr structure
+ * @buffer: buffer being written
+ * @offset: buffer offset for write in total data store area
+ * @count: buffer size
+ *
+ *	Data written to the 'data' attribute will be later handed to
+ *	the driver as a firmware image.
+ **/
+static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
+				   struct bin_attribute *bin_attr,
+				   char *buffer, loff_t offset, size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
+	struct fw_priv *fw_priv;
+	ssize_t retval;
+
+	if (!capable(CAP_SYS_RAWIO))
+		return -EPERM;
+
+	mutex_lock(&fw_lock);
+	fw_priv = fw_sysfs->fw_priv;
+	if (!fw_priv || fw_sysfs_done(fw_priv)) {
+		retval = -ENODEV;
+		goto out;
+	}
+
+	if (fw_priv->data) {
+		if (offset + count > fw_priv->allocated_size) {
+			retval = -ENOMEM;
+			goto out;
+		}
+		firmware_rw_data(fw_priv, buffer, offset, count, false);
+		retval = count;
+	} else {
+		retval = fw_realloc_pages(fw_sysfs, offset + count);
+		if (retval)
+			goto out;
+
+		retval = count;
+		firmware_rw(fw_priv, buffer, offset, count, false);
+	}
+
+	fw_priv->size = max_t(size_t, offset + count, fw_priv->size);
+out:
+	mutex_unlock(&fw_lock);
+	return retval;
+}
+
+static struct bin_attribute firmware_attr_data = {
+	.attr = { .name = "data", .mode = 0644 },
+	.size = 0,
+	.read = firmware_data_read,
+	.write = firmware_data_write,
+};
+
+static struct attribute *fw_dev_attrs[] = {
+	&dev_attr_loading.attr,
+	NULL
+};
+
+static struct bin_attribute *fw_dev_bin_attrs[] = {
+	&firmware_attr_data,
+	NULL
+};
+
+static const struct attribute_group fw_dev_attr_group = {
+	.attrs = fw_dev_attrs,
+	.bin_attrs = fw_dev_bin_attrs,
+};
+
+static const struct attribute_group *fw_dev_attr_groups[] = {
+	&fw_dev_attr_group,
+	NULL
+};
+
+static struct fw_sysfs *
+fw_create_instance(struct firmware *firmware, const char *fw_name,
+		   struct device *device, unsigned int opt_flags)
+{
+	struct fw_sysfs *fw_sysfs;
+	struct device *f_dev;
+
+	fw_sysfs = kzalloc(sizeof(*fw_sysfs), GFP_KERNEL);
+	if (!fw_sysfs) {
+		fw_sysfs = ERR_PTR(-ENOMEM);
+		goto exit;
+	}
+
+	fw_sysfs->nowait = !!(opt_flags & FW_OPT_NOWAIT);
+	fw_sysfs->fw = firmware;
+	f_dev = &fw_sysfs->dev;
+
+	device_initialize(f_dev);
+	dev_set_name(f_dev, "%s", fw_name);
+	f_dev->parent = device;
+	f_dev->class = &firmware_class;
+	f_dev->groups = fw_dev_attr_groups;
+exit:
+	return fw_sysfs;
+}
+
+/**
+ * fw_load_sysfs_fallback - load a firmware via the syfs fallback mechanism
+ * @fw_sysfs: firmware syfs information for the firmware to load
+ * @opt_flags: flags of options, FW_OPT_*
+ * @timeout: timeout to wait for the load
+ *
+ * In charge of constructing a sysfs fallback interface for firmware loading.
+ **/
+static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs,
+				  unsigned int opt_flags, long timeout)
+{
+	int retval = 0;
+	struct device *f_dev = &fw_sysfs->dev;
+	struct fw_priv *fw_priv = fw_sysfs->fw_priv;
+
+	/* fall back on userspace loading */
+	if (!fw_priv->data)
+		fw_priv->is_paged_buf = true;
+
+	dev_set_uevent_suppress(f_dev, true);
+
+	retval = device_add(f_dev);
+	if (retval) {
+		dev_err(f_dev, "%s: device_register failed\n", __func__);
+		goto err_put_dev;
+	}
+
+	mutex_lock(&fw_lock);
+	list_add(&fw_priv->pending_list, &pending_fw_head);
+	mutex_unlock(&fw_lock);
+
+	if (opt_flags & FW_OPT_UEVENT) {
+		fw_priv->need_uevent = true;
+		dev_set_uevent_suppress(f_dev, false);
+		dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_name);
+		kobject_uevent(&fw_sysfs->dev.kobj, KOBJ_ADD);
+	} else {
+		timeout = MAX_JIFFY_OFFSET;
+	}
+
+	retval = fw_sysfs_wait_timeout(fw_priv, timeout);
+	if (retval < 0) {
+		mutex_lock(&fw_lock);
+		fw_load_abort(fw_sysfs);
+		mutex_unlock(&fw_lock);
+	}
+
+	if (fw_state_is_aborted(fw_priv)) {
+		if (retval == -ERESTARTSYS)
+			retval = -EINTR;
+		else
+			retval = -EAGAIN;
+	} else if (fw_priv->is_paged_buf && !fw_priv->data)
+		retval = -ENOMEM;
+
+	device_del(f_dev);
+err_put_dev:
+	put_device(f_dev);
+	return retval;
+}
+
+static int fw_load_from_user_helper(struct firmware *firmware,
+				    const char *name, struct device *device,
+				    unsigned int opt_flags)
+{
+	struct fw_sysfs *fw_sysfs;
+	long timeout;
+	int ret;
+
+	timeout = firmware_loading_timeout();
+	if (opt_flags & FW_OPT_NOWAIT) {
+		timeout = usermodehelper_read_lock_wait(timeout);
+		if (!timeout) {
+			dev_dbg(device, "firmware: %s loading timed out\n",
+				name);
+			return -EBUSY;
+		}
+	} else {
+		ret = usermodehelper_read_trylock();
+		if (WARN_ON(ret)) {
+			dev_err(device, "firmware: %s will not be loaded\n",
+				name);
+			return ret;
+		}
+	}
+
+	fw_sysfs = fw_create_instance(firmware, name, device, opt_flags);
+	if (IS_ERR(fw_sysfs)) {
+		ret = PTR_ERR(fw_sysfs);
+		goto out_unlock;
+	}
+
+	fw_sysfs->fw_priv = firmware->priv;
+	ret = fw_load_sysfs_fallback(fw_sysfs, opt_flags, timeout);
+
+	if (!ret)
+		ret = assign_fw(firmware, device, opt_flags);
+
+out_unlock:
+	usermodehelper_read_unlock();
+
+	return ret;
+}
+
+static bool fw_force_sysfs_fallback(unsigned int opt_flags)
+{
+	if (fw_fallback_config.force_sysfs_fallback)
+		return true;
+	if (!(opt_flags & FW_OPT_USERHELPER))
+		return false;
+	return true;
+}
+
+static bool fw_run_sysfs_fallback(unsigned int opt_flags)
+{
+	if (fw_fallback_config.ignore_sysfs_fallback) {
+		pr_info_once("Ignoring firmware sysfs fallback due to sysctl knob\n");
+		return false;
+	}
+
+	if ((opt_flags & FW_OPT_NOFALLBACK))
+		return false;
+
+	return fw_force_sysfs_fallback(opt_flags);
+}
+
+int fw_sysfs_fallback(struct firmware *fw, const char *name,
+		      struct device *device,
+		      unsigned int opt_flags,
+		      int ret)
+{
+	if (!fw_run_sysfs_fallback(opt_flags))
+		return ret;
+
+	dev_warn(device, "Falling back to user helper\n");
+	return fw_load_from_user_helper(fw, name, device, opt_flags);
+}
diff --git a/drivers/base/firmware_loader/fallback.h b/drivers/base/firmware_loader/fallback.h
new file mode 100644
index 000000000000..dfebc644ed35
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __FIRMWARE_FALLBACK_H
+#define __FIRMWARE_FALLBACK_H
+
+#include <linux/firmware.h>
+#include <linux/device.h>
+
+/**
+ * struct firmware_fallback_config - firmware fallback configuratioon settings
+ *
+ * Helps describe and fine tune the fallback mechanism.
+ *
+ * @force_sysfs_fallback: force the sysfs fallback mechanism to be used
+ * 	as if one had enabled CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y.
+ * 	Useful to help debug a CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y
+ * 	functionality on a kernel where that config entry has been disabled.
+ * @ignore_sysfs_fallback: force to disable the sysfs fallback mechanism.
+ * 	This emulates the behaviour as if we had set the kernel
+ * 	config CONFIG_FW_LOADER_USER_HELPER=n.
+ * @old_timeout: for internal use
+ * @loading_timeout: the timeout to wait for the fallback mechanism before
+ * 	giving up, in seconds.
+ */
+struct firmware_fallback_config {
+	unsigned int force_sysfs_fallback;
+	unsigned int ignore_sysfs_fallback;
+	int old_timeout;
+	int loading_timeout;
+};
+
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+int fw_sysfs_fallback(struct firmware *fw, const char *name,
+		      struct device *device,
+		      unsigned int opt_flags,
+		      int ret);
+void kill_pending_fw_fallback_reqs(bool only_kill_custom);
+
+void fw_fallback_set_cache_timeout(void);
+void fw_fallback_set_default_timeout(void);
+
+int register_sysfs_loader(void);
+void unregister_sysfs_loader(void);
+#else /* CONFIG_FW_LOADER_USER_HELPER */
+static inline int fw_sysfs_fallback(struct firmware *fw, const char *name,
+				    struct device *device,
+				    unsigned int opt_flags,
+				    int ret)
+{
+	/* Keep carrying over the same error */
+	return ret;
+}
+
+static inline void kill_pending_fw_fallback_reqs(bool only_kill_custom) { }
+static inline void fw_fallback_set_cache_timeout(void) { }
+static inline void fw_fallback_set_default_timeout(void) { }
+
+static inline int register_sysfs_loader(void)
+{
+	return 0;
+}
+
+static inline void unregister_sysfs_loader(void)
+{
+}
+#endif /* CONFIG_FW_LOADER_USER_HELPER */
+
+#endif /* __FIRMWARE_FALLBACK_H */
diff --git a/drivers/base/firmware_loader/fallback_table.c b/drivers/base/firmware_loader/fallback_table.c
new file mode 100644
index 000000000000..7428659d8df9
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback_table.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/types.h>
+#include <linux/kconfig.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/highmem.h>
+#include <linux/umh.h>
+#include <linux/sysctl.h>
+
+#include "fallback.h"
+#include "firmware.h"
+
+/*
+ * firmware fallback configuration table
+ */
+
+/* Module or buit-in */
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+
+static unsigned int zero;
+static unsigned int one = 1;
+
+struct firmware_fallback_config fw_fallback_config = {
+	.force_sysfs_fallback = IS_ENABLED(CONFIG_FW_LOADER_USER_HELPER_FALLBACK),
+	.loading_timeout = 60,
+	.old_timeout = 60,
+};
+EXPORT_SYMBOL_GPL(fw_fallback_config);
+
+struct ctl_table firmware_config_table[] = {
+	{
+		.procname	= "force_sysfs_fallback",
+		.data		= &fw_fallback_config.force_sysfs_fallback,
+		.maxlen         = sizeof(unsigned int),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &one,
+	},
+	{
+		.procname	= "ignore_sysfs_fallback",
+		.data		= &fw_fallback_config.ignore_sysfs_fallback,
+		.maxlen         = sizeof(unsigned int),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &one,
+	},
+	{ }
+};
+EXPORT_SYMBOL_GPL(firmware_config_table);
+
+#endif
diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
new file mode 100644
index 000000000000..64acbb1a392c
--- /dev/null
+++ b/drivers/base/firmware_loader/firmware.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __FIRMWARE_LOADER_H
+#define __FIRMWARE_LOADER_H
+
+#include <linux/firmware.h>
+#include <linux/types.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/completion.h>
+
+#include <generated/utsrelease.h>
+
+/* firmware behavior options */
+#define FW_OPT_UEVENT			(1U << 0)
+#define FW_OPT_NOWAIT			(1U << 1)
+#define FW_OPT_USERHELPER		(1U << 2)
+#define FW_OPT_NO_WARN			(1U << 3)
+#define FW_OPT_NOCACHE			(1U << 4)
+#define FW_OPT_NOFALLBACK		(1U << 5)
+
+enum fw_status {
+	FW_STATUS_UNKNOWN,
+	FW_STATUS_LOADING,
+	FW_STATUS_DONE,
+	FW_STATUS_ABORTED,
+};
+
+/*
+ * Concurrent request_firmware() for the same firmware need to be
+ * serialized.  struct fw_state is simple state machine which hold the
+ * state of the firmware loading.
+ */
+struct fw_state {
+	struct completion completion;
+	enum fw_status status;
+};
+
+struct fw_priv {
+	struct kref ref;
+	struct list_head list;
+	struct firmware_cache *fwc;
+	struct fw_state fw_st;
+	void *data;
+	size_t size;
+	size_t allocated_size;
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+	bool is_paged_buf;
+	bool need_uevent;
+	struct page **pages;
+	int nr_pages;
+	int page_array_size;
+	struct list_head pending_list;
+#endif
+	const char *fw_name;
+};
+
+extern struct mutex fw_lock;
+
+static inline bool __fw_state_check(struct fw_priv *fw_priv,
+				    enum fw_status status)
+{
+	struct fw_state *fw_st = &fw_priv->fw_st;
+
+	return fw_st->status == status;
+}
+
+static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
+{
+	struct fw_state *fw_st = &fw_priv->fw_st;
+	long ret;
+
+	ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
+	if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
+		return -ENOENT;
+	if (!ret)
+		return -ETIMEDOUT;
+
+	return ret < 0 ? ret : 0;
+}
+
+static inline void __fw_state_set(struct fw_priv *fw_priv,
+				  enum fw_status status)
+{
+	struct fw_state *fw_st = &fw_priv->fw_st;
+
+	WRITE_ONCE(fw_st->status, status);
+
+	if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
+		complete_all(&fw_st->completion);
+}
+
+static inline void fw_state_aborted(struct fw_priv *fw_priv)
+{
+	__fw_state_set(fw_priv, FW_STATUS_ABORTED);
+}
+
+static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
+{
+	return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
+}
+
+static inline void fw_state_start(struct fw_priv *fw_priv)
+{
+	__fw_state_set(fw_priv, FW_STATUS_LOADING);
+}
+
+static inline void fw_state_done(struct fw_priv *fw_priv)
+{
+	__fw_state_set(fw_priv, FW_STATUS_DONE);
+}
+
+int assign_fw(struct firmware *fw, struct device *device,
+	      unsigned int opt_flags);
+
+#endif /* __FIRMWARE_LOADER_H */
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_loader/main.c
index 7dd36ace6152..eb34089e4299 100644
--- a/