Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

10 files changed, 2824 insertions, 0 deletions

diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig
new file mode 100644
index 000000000..5b24f3959
--- /dev/null
+++ b/drivers/base/firmware_loader/Kconfig
@@ -0,0 +1,185 @@
+# SPDX-License-Identifier: GPL-2.0
+menu "Firmware loader"
+
+config FW_LOADER
+	tristate "Firmware loading facility" if EXPERT
+	default y
+	help
+	  This enables the firmware loading facility in the kernel. The kernel
+	  will first look for built-in firmware, if it has any. Next, it will
+	  look for the requested firmware in a series of filesystem paths:
+
+		o firmware_class path module parameter or kernel boot param
+		o /lib/firmware/updates/UTS_RELEASE
+		o /lib/firmware/updates
+		o /lib/firmware/UTS_RELEASE
+		o /lib/firmware
+
+	  Enabling this feature only increases your kernel image by about
+	  828 bytes, enable this option unless you are certain you don't
+	  need firmware.
+
+	  You typically want this built-in (=y) but you can also enable this
+	  as a module, in which case the firmware_class module will be built.
+	  You also want to be sure to enable this built-in if you are going to
+	  enable built-in firmware (CONFIG_EXTRA_FIRMWARE).
+
+if FW_LOADER
+
+config FW_LOADER_PAGED_BUF
+	bool
+
+config EXTRA_FIRMWARE
+	string "Build named firmware blobs into the kernel binary"
+	help
+	  Device drivers which require firmware can typically deal with
+	  having the kernel load firmware from the various supported
+	  /lib/firmware/ paths. This option enables you to build into the
+	  kernel firmware files. Built-in firmware searches are preceded
+	  over firmware lookups using your filesystem over the supported
+	  /lib/firmware paths documented on CONFIG_FW_LOADER.
+
+	  This may be useful for testing or if the firmware is required early on
+	  in boot and cannot rely on the firmware being placed in an initrd or
+	  initramfs.
+
+	  This option is a string and takes the (space-separated) names of the
+	  firmware files -- the same names that appear in MODULE_FIRMWARE()
+	  and request_firmware() in the source. These files should exist under
+	  the directory specified by the EXTRA_FIRMWARE_DIR option, which is
+	  /lib/firmware by default.
+
+	  For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
+	  the usb8388.bin file into /lib/firmware, and build the kernel. Then
+	  any request_firmware("usb8388.bin") will be satisfied internally
+	  inside the kernel without ever looking at your filesystem at runtime.
+
+	  WARNING: If you include additional firmware files into your binary
+	  kernel image that are not available under the terms of the GPL,
+	  then it may be a violation of the GPL to distribute the resulting
+	  image since it combines both GPL and non-GPL work. You should
+	  consult a lawyer of your own before distributing such an image.
+
+config EXTRA_FIRMWARE_DIR
+	string "Firmware blobs root directory"
+	depends on EXTRA_FIRMWARE != ""
+	default "/lib/firmware"
+	help
+	  This option controls the directory in which the kernel build system
+	  looks for the firmware files listed in the EXTRA_FIRMWARE option.
+
+config FW_LOADER_USER_HELPER
+	bool "Enable the firmware sysfs fallback mechanism"
+	select FW_LOADER_PAGED_BUF
+	help
+	  This option enables a sysfs loading facility to enable firmware
+	  loading to the kernel through userspace as a fallback mechanism
+	  if and only if the kernel's direct filesystem lookup for the
+	  firmware failed using the different /lib/firmware/ paths, or the
+	  path specified in the firmware_class path module parameter, or the
+	  firmware_class path kernel boot parameter if the firmware_class is
+	  built-in. For details on how to work with the sysfs fallback mechanism
+	  refer to Documentation/driver-api/firmware/fallback-mechanisms.rst.
+
+	  The direct filesystem lookup for firmware is always used first now.
+
+	  If the kernel's direct filesystem lookup for firmware fails to find
+	  the requested firmware a sysfs fallback loading facility is made
+	  available and userspace is informed about this through uevents.
+	  The uevent can be suppressed if the driver explicitly requested it,
+	  this is known as the driver using the custom fallback mechanism.
+	  If the custom fallback mechanism is used userspace must always
+	  acknowledge failure to find firmware as the timeout for the fallback
+	  mechanism is disabled, and failed requests will linger forever.
+
+	  This used to be the default firmware loading facility, and udev used
+	  to listen for uvents to load firmware for the kernel. The firmware
+	  loading facility functionality in udev has been removed, as such it
+	  can no longer be relied upon as a fallback mechanism. Linux no longer
+	  relies on or uses a fallback mechanism in userspace. If you need to
+	  rely on one refer to the permissively licensed firmwared:
+
+	  https://github.com/teg/firmwared
+
+	  Since this was the default firmware loading facility at one point,
+	  old userspace may exist which relies upon it, and as such this
+	  mechanism can never be removed from the kernel.
+
+	  You should only enable this functionality if you are certain you
+	  require a fallback mechanism and have a userspace mechanism ready to
+	  load firmware in case it is not found. One main reason for this may
+	  be if you have drivers which require firmware built-in and for
+	  whatever reason cannot place the required firmware in initramfs.
+	  Another reason kernels may have this feature enabled is to support a
+	  driver which explicitly relies on this fallback mechanism. Only two
+	  drivers need this today:
+
+	    o CONFIG_LEDS_LP55XX_COMMON
+	    o CONFIG_DELL_RBU
+
+	  Outside of supporting the above drivers, another reason for needing
+	  this may be that your firmware resides outside of the paths the kernel
+	  looks for and cannot possibly be specified using the firmware_class
+	  path module parameter or kernel firmware_class path boot parameter
+	  if firmware_class is built-in.
+
+	  A modern use case may be to temporarily mount a custom partition
+	  during provisioning which is only accessible to userspace, and then
+	  to use it to look for and fetch the required firmware. Such type of
+	  driver functionality may not even ever be desirable upstream by
+	  vendors, and as such is only required to be supported as an interface
+	  for provisioning. Since udev's firmware loading facility has been
+	  removed you can use firmwared or a fork of it to customize how you
+	  want to load firmware based on uevents issued.
+
+	  Enabling this option will increase your kernel image size by about
+	  13436 bytes.
+
+	  If you are unsure about this, say N here, unless you are Linux
+	  distribution and need to support the above two drivers, or you are
+	  certain you need to support some really custom firmware loading
+	  facility in userspace.
+
+config FW_LOADER_USER_HELPER_FALLBACK
+	bool "Force the firmware sysfs fallback mechanism when possible"
+	depends on FW_LOADER_USER_HELPER
+	help
+	  Enabling this option forces a sysfs userspace fallback mechanism
+	  to be used for all firmware requests which explicitly do not disable a
+	  a fallback mechanism. Firmware calls which do prohibit a fallback
+	  mechanism is request_firmware_direct(). This option is kept for
+	  backward compatibility purposes given this precise mechanism can also
+	  be enabled by setting the proc sysctl value to true:
+
+	       /proc/sys/kernel/firmware_config/force_sysfs_fallback
+
+	  If you are unsure about this, say N here.
+
+config FW_LOADER_COMPRESS
+	bool "Enable compressed firmware support"
+	select FW_LOADER_PAGED_BUF
+	select XZ_DEC
+	help
+	  This option enables the support for loading compressed firmware
+	  files. The caller of firmware API receives the decompressed file
+	  content. The compressed file is loaded as a fallback, only after
+	  loading the raw file failed at first.
+
+	  Currently only XZ-compressed files are supported, and they have to
+	  be compressed with either none or crc32 integrity check type (pass
+	  "-C crc32" option to xz command).
+
+config FW_CACHE
+	bool "Enable firmware caching during suspend"
+	depends on PM_SLEEP
+	default y if PM_SLEEP
+	help
+	  Because firmware caching generates uevent messages that are sent
+	  over a netlink socket, it can prevent suspend on many platforms.
+	  It is also not always useful, so on such platforms we have the
+	  option.
+
+	  If unsure, say Y.
+
+endif # FW_LOADER
+endmenu
diff --git a/drivers/base/firmware_loader/Makefile b/drivers/base/firmware_loader/Makefile
new file mode 100644
index 000000000..e87843408
--- /dev/null
+++ b/drivers/base/firmware_loader/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for the Linux firmware loader
+
+obj-$(CONFIG_FW_LOADER_USER_HELPER) += fallback_table.o
+obj-$(CONFIG_FW_LOADER)	+= firmware_class.o
+firmware_class-objs := main.o
+firmware_class-$(CONFIG_FW_LOADER_USER_HELPER) += fallback.o
+firmware_class-$(CONFIG_EFI_EMBEDDED_FIRMWARE) += fallback_platform.o
+
+obj-y += builtin/
diff --git a/drivers/base/firmware_loader/builtin/.gitignore b/drivers/base/firmware_loader/builtin/.gitignore
new file mode 100644
index 000000000..166f76b43
--- /dev/null
+++ b/drivers/base/firmware_loader/builtin/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+*.gen.S
diff --git a/drivers/base/firmware_loader/builtin/Makefile b/drivers/base/firmware_loader/builtin/Makefile
new file mode 100644
index 000000000..5fa7ce374
--- /dev/null
+++ b/drivers/base/firmware_loader/builtin/Makefile
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Create $(fwdir) from $(CONFIG_EXTRA_FIRMWARE_DIR) -- if it doesn't have a
+# leading /, it's relative to $(srctree).
+fwdir := $(subst $(quote),,$(CONFIG_EXTRA_FIRMWARE_DIR))
+fwdir := $(addprefix $(srctree)/,$(filter-out /%,$(fwdir)))$(filter /%,$(fwdir))
+
+obj-y  := $(addsuffix .gen.o, $(subst $(quote),,$(CONFIG_EXTRA_FIRMWARE)))
+
+FWNAME    = $(patsubst $(obj)/%.gen.S,%,$@)
+comma     := ,
+FWSTR     = $(subst $(comma),_,$(subst /,_,$(subst .,_,$(subst -,_,$(FWNAME)))))
+ASM_WORD  = $(if $(CONFIG_64BIT),.quad,.long)
+ASM_ALIGN = $(if $(CONFIG_64BIT),3,2)
+PROGBITS  = $(if $(CONFIG_ARM),%,@)progbits
+
+filechk_fwbin = \
+	echo "/* Generated by $(src)/Makefile */"		;\
+	echo "    .section .rodata"				;\
+	echo "    .p2align 4"					;\
+	echo "_fw_$(FWSTR)_bin:"				;\
+	echo "    .incbin \"$(fwdir)/$(FWNAME)\""		;\
+	echo "_fw_end:"						;\
+	echo "    .section .rodata.str,\"aMS\",$(PROGBITS),1"	;\
+	echo "    .p2align $(ASM_ALIGN)"			;\
+	echo "_fw_$(FWSTR)_name:"				;\
+	echo "    .string \"$(FWNAME)\""			;\
+	echo "    .section .builtin_fw,\"a\",$(PROGBITS)"	;\
+	echo "    .p2align $(ASM_ALIGN)"			;\
+	echo "    $(ASM_WORD) _fw_$(FWSTR)_name"		;\
+	echo "    $(ASM_WORD) _fw_$(FWSTR)_bin"			;\
+	echo "    $(ASM_WORD) _fw_end - _fw_$(FWSTR)_bin"
+
+$(obj)/%.gen.S: FORCE
+	$(call filechk,fwbin)
+
+# The .o files depend on the binaries directly; the .S files don't.
+$(addprefix $(obj)/, $(obj-y)): $(obj)/%.gen.o: $(fwdir)/%
+
+targets := $(patsubst $(obj)/%,%, \
+                                $(shell find $(obj) -name \*.gen.S 2>/dev/null))
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
new file mode 100644
index 000000000..0fdd18ce2
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback.c
@@ -0,0 +1,660 @@
+// 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 <linux/module.h>
+
+#include "fallback.h"
+#include "firmware.h"
+
+/*
+ * firmware fallback mechanism
+ */
+
+MODULE_IMPORT_NS(FIRMWARE_LOADER_PRIVATE);
+
+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/aborted and disappearance of 'loading'
+	 */
+	if (fw_state_is_aborted(fw_priv) || fw_sysfs_done(fw_priv))
+		return;
+
+	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 sysfs_emit(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 sysfs_emit(buf, "%d\n", loading);
+}
+
+/**
+ * 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);
+
+	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)) {
+			fw_free_paged_buf(fw_priv);
+			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 = fw_map_paged_buf(fw_priv);
+			if (rc)
+				dev_err(dev, "%s: map pages failed\n",
+					__func__);
+			else
+				rc = security_kernel_post_load_data(fw_priv->data,
+						fw_priv->size,
+						LOADING_FIRMWARE, "blob");
+
+			/*
+			 * Same logic as fw_load_abort, only the DONE bit
+			 * is ignored and we set ABORT only on failure.
+			 */
+			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)
+{
+	int err;
+
+	err = fw_grow_paged_buf(fw_sysfs->fw_priv,
+				PAGE_ALIGN(min_size) >> PAGE_SHIFT);
+	if (err)
+		fw_load_abort(fw_sysfs);
+	return err;
+}
+
+/**
+ * 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, u32 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 sysfs fallback mechanism
+ * @fw_sysfs: firmware sysfs information for the firmware to load
+ * @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, 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);
+	if (fw_state_is_aborted(fw_priv)) {
+		mutex_unlock(&fw_lock);
+		retval = -EINTR;
+		goto out;
+	}
+	list_add(&fw_priv->pending_list, &pending_fw_head);
+	mutex_unlock(&fw_lock);
+
+	if (fw_priv->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 && retval != -ENOENT) {
+		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 if (fw_priv->is_paged_buf && !fw_priv->data)
+		retval = -ENOMEM;
+
+out:
+	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,
+				    u32 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, timeout);
+
+	if (!ret)
+		ret = assign_fw(firmware, device);
+
+out_unlock:
+	usermodehelper_read_unlock();
+
+	return ret;
+}
+
+static bool fw_force_sysfs_fallback(u32 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(u32 opt_flags)
+{
+	int ret;
+
+	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_SYSFS))
+		return false;
+
+	/* Also permit LSMs and IMA to fail firmware sysfs fallback */
+	ret = security_kernel_load_data(LOADING_FIRMWARE, true);
+	if (ret < 0)
+		return false;
+
+	return fw_force_sysfs_fallback(opt_flags);
+}
+
+/**
+ * firmware_fallback_sysfs() - use the fallback mechanism to find firmware
+ * @fw: pointer to firmware image
+ * @name: name of firmware file to look for
+ * @device: device for which firmware is being loaded
+ * @opt_flags: options to control firmware loading behaviour, as defined by
+ *	       &enum fw_opt
+ * @ret: return value from direct lookup which triggered the fallback mechanism
+ *
+ * This function is called if direct lookup for the firmware failed, it enables
+ * a fallback mechanism through userspace by exposing a sysfs loading
+ * interface. Userspace is in charge of loading the firmware through the sysfs
+ * loading interface. This sysfs fallback mechanism may be disabled completely
+ * on a system by setting the proc sysctl value ignore_sysfs_fallback to true.
+ * If this is false we check if the internal API caller set the
+ * @FW_OPT_NOFALLBACK_SYSFS flag, if so it would also disable the fallback
+ * mechanism. A system may want to enforce the sysfs fallback mechanism at all
+ * times, it can do this by setting ignore_sysfs_fallback to false and
+ * force_sysfs_fallback to true.
+ * Enabling force_sysfs_fallback is functionally equivalent to build a kernel
+ * with CONFIG_FW_LOADER_USER_HELPER_FALLBACK.
+ **/
+int firmware_fallback_sysfs(struct firmware *fw, const char *name,
+			    struct device *device,
+			    u32 opt_flags,
+			    int ret)
+{
+	if (!fw_run_sysfs_fallback(opt_flags))
+		return ret;
+
+	if (!(opt_flags & FW_OPT_NO_WARN))
+		dev_warn(device, "Falling back to sysfs fallback for: %s\n",
+				 name);
+	else
+		dev_dbg(device, "Falling back to sysfs fallback for: %s\n",
+				name);
+	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 000000000..3af7205b3
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __FIRMWARE_FALLBACK_H
+#define __FIRMWARE_FALLBACK_H
+
+#include <linux/firmware.h>
+#include <linux/device.h>
+
+#include "firmware.h"
+
+/**
+ * struct firmware_fallback_config - firmware fallback configuration 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 firmware_fallback_sysfs(struct firmware *fw, const char *name,
+			    struct device *device,
+			    u32 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 firmware_fallback_sysfs(struct firmware *fw, const char *name,
+					  struct device *device,
+					  u32 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 */
+
+#ifdef CONFIG_EFI_EMBEDDED_FIRMWARE
+int firmware_fallback_platform(struct fw_priv *fw_priv);
+#else
+static inline int firmware_fallback_platform(struct fw_priv *fw_priv)
+{
+	return -ENOENT;
+}
+#endif
+
+#endif /* __FIRMWARE_FALLBACK_H */
diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c
new file mode 100644
index 000000000..00af99f0a
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback_platform.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/efi_embedded_fw.h>
+#include <linux/property.h>
+#include <linux/security.h>
+#include <linux/vmalloc.h>
+
+#include "fallback.h"
+#include "firmware.h"
+
+int firmware_fallback_platform(struct fw_priv *fw_priv)
+{
+	const u8 *data;
+	size_t size;
+	int rc;
+
+	if (!(fw_priv->opt_flags & FW_OPT_FALLBACK_PLATFORM))
+		return -ENOENT;
+
+	rc = security_kernel_load_data(LOADING_FIRMWARE, true);
+	if (rc)
+		return rc;
+
+	rc = efi_get_embedded_fw(fw_priv->fw_name, &data, &size);
+	if (rc)
+		return rc; /* rc == -ENOENT when the fw was not found */
+
+	if (fw_priv->data && size > fw_priv->allocated_size)
+		return -ENOMEM;
+
+	rc = security_kernel_post_load_data((u8 *)data, size, LOADING_FIRMWARE,
+						"platform");
+	if (rc)
+		return rc;
+
+	if (!fw_priv->data)
+		fw_priv->data = vmalloc(size);
+	if (!fw_priv->data)
+		return -ENOMEM;
+
+	memcpy(fw_priv->data, data, size);
+	fw_priv->size = size;
+	fw_state_done(fw_priv);
+	return 0;
+}
diff --git a/drivers/base/firmware_loader/fallback_table.c b/drivers/base/firmware_loader/fallback_table.c
new file mode 100644
index 000000000..46a731ded
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback_table.c
@@ -0,0 +1,48 @@
+// 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
+ */
+
+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_NS_GPL(fw_fallback_config, FIRMWARE_LOADER_PRIVATE);
+
+#ifdef CONFIG_SYSCTL
+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		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{
+		.procname	= "ignore_sysfs_fallback",
+		.data		= &fw_fallback_config.ignore_sysfs_fallback,
+		.maxlen         = sizeof(unsigned int),
+		.mode           = 0644,
+		.proc_handler   = proc_douintvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{ }
+};
+#endif
diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
new file mode 100644
index 000000000..a3014e9e2
--- /dev/null
+++ b/drivers/base/firmware_loader/firmware.h
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __FIRMWARE_LOADER_H
+#define __FIRMWARE_LOADER_H
+
+#include <linux/bitops.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>
+
+/**
+ * enum fw_opt - options to control firmware loading behaviour
+ *
+ * @FW_OPT_UEVENT: Enables the fallback mechanism to send a kobject uevent
+ *	when the firmware is not found. Userspace is in charge to load the
+ *	firmware using the sysfs loading facility.
+ * @FW_OPT_NOWAIT: Used to describe the firmware request is asynchronous.
+ * @FW_OPT_USERHELPER: Enable the fallback mechanism, in case the direct
+ *	filesystem lookup fails at finding the firmware.  For details refer to
+ *	firmware_fallback_sysfs().
+ * @FW_OPT_NO_WARN: Quiet, avoid printing warning messages.
+ * @FW_OPT_NOCACHE: Disables firmware caching. Firmware caching is used to
+ *	cache the firmware upon suspend, so that upon resume races against the
+ *	firmware file lookup on storage is avoided. Used for calls where the
+ *	file may be too big, or where the driver takes charge of its own
+ *	firmware caching mechanism.
+ * @FW_OPT_NOFALLBACK_SYSFS: Disable the sysfs fallback mechanism. Takes
+ *	precedence over &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
+ * @FW_OPT_FALLBACK_PLATFORM: Enable fallback to device fw copy embedded in
+ *	the platform's main firmware. If both this fallback and the sysfs
+ *      fallback are enabled, then this fallback will be tried first.
+ * @FW_OPT_PARTIAL: Allow partial read of firmware instead of needing to read
+ *	entire file.
+ */
+enum fw_opt {
+	FW_OPT_UEVENT			= BIT(0),
+	FW_OPT_NOWAIT			= BIT(1),
+	FW_OPT_USERHELPER		= BIT(2),
+	FW_OPT_NO_WARN			= BIT(3),
+	FW_OPT_NOCACHE			= BIT(4),
+	FW_OPT_NOFALLBACK_SYSFS		= BIT(5),
+	FW_OPT_FALLBACK_PLATFORM	= BIT(6),
+	FW_OPT_PARTIAL			= BIT(7),
+};
+
+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;
+	size_t offset;
+	u32 opt_flags;
+#ifdef CONFIG_FW_LOADER_PAGED_BUF
+	bool is_paged_buf;
+	struct page **pages;
+	int nr_pages;
+	int page_array_size;
+#endif
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+	bool need_uevent;
+	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) {
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+		/*
+		 * Doing this here ensures that the fw_priv is deleted from
+		 * the pending list in all abort/done paths.
+		 */
+		list_del_init(&fw_priv->pending_list);
+#endif
+		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);
+
+#ifdef CONFIG_FW_LOADER_PAGED_BUF
+void fw_free_paged_buf(struct fw_priv *fw_priv);
+int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
+int fw_map_paged_buf(struct fw_priv *fw_priv);
+bool fw_is_paged_buf(struct fw_priv *fw_priv);
+#else
+static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
+static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
+static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
+static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
+#endif
+
+#endif /* __FIRMWARE_LOADER_H */
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
new file mode 100644
index 000000000..a4dd500bc
--- /dev/null
+++ b/drivers/base/firmware_loader/main.c
@@ -0,0 +1,1589 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * main.c - Multi purpose firmware loading support
+ *
+ * Copyright (c) 2003 Manuel Estrada Sainz
+ *
+ * Please see Documentation/driver-api/firmware/ for more information.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/capability.h>
+#include <linux/device.h>
+#include <linux/kernel_read_file.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/vmalloc.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <linux/mutex.h>
+#include <linux/workqueue.h>
+#include <linux/highmem.h>
+#include <linux/firmware.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/file.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/async.h>
+#include <linux/pm.h>
+#include <linux/suspend.h>
+#include <linux/syscore_ops.h>
+#include <linux/reboot.h>
+#include <linux/security.h>
+#include <linux/xz.h>
+
+#include <generated/utsrelease.h>
+
+#include "../base.h"
+#include "firmware.h"
+#include "fallback.h"
+
+MODULE_AUTHOR("Manuel Estrada Sainz");
+MODULE_DESCRIPTION("Multi purpose firmware loading support");
+MODULE_LICENSE("GPL");
+
+struct firmware_cache {
+	/* firmware_buf instance will be added into the below list */
+	spinlock_t lock;
+	struct list_head head;
+	int state;
+
+#ifdef CONFIG_FW_CACHE
+	/*
+	 * Names of firmware images which have been cached successfully
+	 * will be added into the below list so that device uncache
+	 * helper can trace which firmware images have been cached
+	 * before.
+	 */
+	spinlock_t name_lock;
+	struct list_head fw_names;
+
+	struct delayed_work work;
+
+	struct notifier_block   pm_notify;
+#endif
+};
+
+struct fw_cache_entry {
+	struct list_head list;
+	const char *name;
+};
+
+struct fw_name_devm {
+	unsigned long magic;
+	const char *name;
+};
+
+static inline struct fw_priv *to_fw_priv(struct kref *ref)
+{
+	return container_of(ref, struct fw_priv, ref);
+}
+
+#define	FW_LOADER_NO_CACHE	0
+#define	FW_LOADER_START_CACHE	1
+
+/* fw_lock could be moved to 'struct fw_sysfs' but since it is just
+ * guarding for corner cases a global lock should be OK */
+DEFINE_MUTEX(fw_lock);
+
+static struct firmware_cache fw_cache;
+
+/* Builtin firmware support */
+
+#ifdef CONFIG_FW_LOADER
+
+extern struct builtin_fw __start_builtin_fw[];
+extern struct builtin_fw __end_builtin_fw[];
+
+static bool fw_copy_to_prealloc_buf(struct firmware *fw,
+				    void *buf, size_t size)
+{
+	if (!buf)
+		return true;
+	if (size < fw->size)
+		return false;
+	memcpy(buf, fw->data, fw->size);
+	return true;
+}
+
+static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
+				    void *buf, size_t size)
+{
+	struct builtin_fw *b_fw;
+
+	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
+		if (strcmp(name, b_fw->name) == 0) {
+			fw->size = b_fw->size;
+			fw->data = b_fw->data;
+			return fw_copy_to_prealloc_buf(fw, buf, size);
+		}
+	}
+
+	return false;
+}
+
+static bool fw_is_builtin_firmware(const struct firmware *fw)
+{
+	struct builtin_fw *b_fw;
+
+	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
+		if (fw->data == b_fw->data)
+			return true;
+
+	return false;
+}
+
+#else /* Module case - no builtin firmware support */
+
+static inline bool fw_get_builtin_firmware(struct firmware *fw,
+					   const char *name, void *buf,
+					   size_t size)
+{
+	return false;
+}
+
+static inline bool fw_is_builtin_firmware(const struct firmware *fw)
+{
+	return false;
+}
+#endif
+
+static void fw_state_init(struct fw_priv *fw_priv)
+{
+	struct fw_state *fw_st = &fw_priv->fw_st;
+
+	init_completion(&fw_st->completion);
+	fw_st->status = FW_STATUS_UNKNOWN;
+}
+
+static inline int fw_state_wait(struct fw_priv *fw_priv)
+{
+	return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
+}
+
+static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv);
+
+static struct fw_priv *__allocate_fw_priv(const char *fw_name,
+					  struct firmware_cache *fwc,
+					  void *dbuf,
+					  size_t size,
+					  size_t offset,
+					  u32 opt_flags)
+{
+	struct fw_priv *fw_priv;
+
+	/* For a partial read, the buffer must be preallocated. */
+	if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
+		return NULL;
+
+	/* Only partial reads are allowed to use an offset. */
+	if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
+		return NULL;
+
+	fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
+	if (!fw_priv)
+		return NULL;
+
+	fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
+	if (!fw_priv->fw_name) {
+		kfree(fw_priv);
+		return NULL;
+	}
+
+	kref_init(&fw_priv->ref);
+	fw_priv->fwc = fwc;
+	fw_priv->data = dbuf;
+	fw_priv->allocated_size = size;
+	fw_priv->offset = offset;
+	fw_priv->opt_flags = opt_flags;
+	fw_state_init(fw_priv);
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+	INIT_LIST_HEAD(&fw_priv->pending_list);
+#endif
+
+	pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
+
+	return fw_priv;
+}
+
+static struct fw_priv *__lookup_fw_priv(const char *fw_name)
+{
+	struct fw_priv *tmp;
+	struct firmware_cache *fwc = &fw_cache;
+
+	list_for_each_entry(tmp, &fwc->head, list)
+		if (!strcmp(tmp->fw_name, fw_name))
+			return tmp;
+	return NULL;
+}
+
+/* Returns 1 for batching firmware requests with the same name */
+static int alloc_lookup_fw_priv(const char *fw_name,
+				struct firmware_cache *fwc,
+				struct fw_priv **fw_priv,
+				void *dbuf,
+				size_t size,
+				size_t offset,
+				u32 opt_flags)
+{
+	struct fw_priv *tmp;
+
+	spin_lock(&fwc->lock);
+	/*
+	 * Do not merge requests that are marked to be non-cached or
+	 * are performing partial reads.
+	 */
+	if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
+		tmp = __lookup_fw_priv(fw_name);
+		if (tmp) {
+			kref_get(&tmp->ref);
+			spin_unlock(&fwc->lock);
+			*fw_priv = tmp;
+			pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
+			return 1;
+		}
+	}
+
+	tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
+	if (tmp) {
+		INIT_LIST_HEAD(&tmp->list);
+		if (!(opt_flags & FW_OPT_NOCACHE))
+			list_add(&tmp->list, &fwc->head);
+	}
+	spin_unlock(&fwc->lock);
+
+	*fw_priv = tmp;
+
+	return tmp ? 0 : -ENOMEM;
+}
+
+static void __free_fw_priv(struct kref *ref)
+	__releases(&fwc->lock)
+{
+	struct fw_priv *fw_priv = to_fw_priv(ref);
+	struct firmware_cache *fwc = fw_priv->fwc;
+
+	pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
+		 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
+		 (unsigned int)fw_priv->size);
+
+	list_del(&fw_priv->list);
+	spin_unlock(&fwc->lock);
+
+	if (fw_is_paged_buf(fw_priv))
+		fw_free_paged_buf(fw_priv);
+	else if (!fw_priv->allocated_size)
+		vfree(fw_priv->data);
+
+	kfree_const(fw_priv->fw_name);
+	kfree(fw_priv);
+}
+
+static void free_fw_priv(struct fw_priv *fw_priv)
+{
+	struct firmware_cache *fwc = fw_priv->fwc;
+	spin_lock(&fwc->lock);
+	if (!kref_put(&fw_priv->ref, __free_fw_priv))
+		spin_unlock(&fwc->lock);
+}
+
+#ifdef CONFIG_FW_LOADER_PAGED_BUF
+bool fw_is_paged_buf(struct fw_priv *fw_priv)
+{
+	return fw_priv->is_paged_buf;
+}
+
+void fw_free_paged_buf(struct fw_priv *fw_priv)
+{
+	int i;
+
+	if (!fw_priv->pages)
+		return;
+
+	vunmap(fw_priv->data);
+
+	for (i = 0; i < fw_priv->nr_pages; i++)
+		__free_page(fw_priv->pages[i]);
+	kvfree(fw_priv->pages);
+	fw_priv->pages = NULL;
+	fw_priv->page_array_size = 0;
+	fw_priv->nr_pages = 0;
+}
+
+int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
+{
+	/* 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 = kvmalloc_array(new_array_size, sizeof(void *),
+					   GFP_KERNEL);
+		if (!new_pages)
+			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));
+		kvfree(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])
+			return -ENOMEM;
+		fw_priv->nr_pages++;
+	}
+
+	return 0;
+}
+
+int fw_map_paged_buf(struct fw_priv *fw_priv)
+{
+	/* one pages buffer should be mapped/unmapped only once */
+	if (!fw_priv->pages)
+		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;
+}
+#endif
+
+/*
+ * XZ-compressed firmware support
+ */
+#ifdef CONFIG_FW_LOADER_COMPRESS
+/* show an error and return the standard error code */
+static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
+{
+	if (xz_ret != XZ_STREAM_END) {
+		dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
+		return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
+	}
+	return 0;
+}
+
+/* single-shot decompression onto the pre-allocated buffer */
+static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
+				   size_t in_size, const void *in_buffer)
+{
+	struct xz_dec *xz_dec;
+	struct xz_buf xz_buf;
+	enum xz_ret xz_ret;
+
+	xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
+	if (!xz_dec)
+		return -ENOMEM;
+
+	xz_buf.in_size = in_size;
+	xz_buf.in = in_buffer;
+	xz_buf.in_pos = 0;
+	xz_buf.out_size = fw_priv->allocated_size;
+	xz_buf.out = fw_priv->data;
+	xz_buf.out_pos = 0;
+
+	xz_ret = xz_dec_run(xz_dec, &xz_buf);
+	xz_dec_end(xz_dec);
+
+	fw_priv->size = xz_buf.out_pos;
+	return fw_decompress_xz_error(dev, xz_ret);
+}
+
+/* decompression on paged buffer and map it */
+static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
+				  size_t in_size, const void *in_buffer)
+{
+	struct xz_dec *xz_dec;
+	struct xz_buf xz_buf;
+	enum xz_ret xz_ret;
+	struct page *page;
+	int err = 0;
+
+	xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
+	if (!xz_dec)
+		return -ENOMEM;
+
+	xz_buf.in_size = in_size;
+	xz_buf.in = in_buffer;
+	xz_buf.in_pos = 0;
+
+	fw_priv->is_paged_buf = true;
+	fw_priv->size = 0;
+	do {
+		if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
+			err = -ENOMEM;
+			goto out;
+		}
+
+		/* decompress onto the new allocated page */
+		page = fw_priv->pages[fw_priv->nr_pages - 1];
+		xz_buf.out = kmap(page);
+		xz_buf.out_pos = 0;
+		xz_buf.out_size = PAGE_SIZE;
+		xz_ret = xz_dec_run(xz_dec, &xz_buf);
+		kunmap(page);
+		fw_priv->size += xz_buf.out_pos;
+		/* partial decompression means either end or error */
+		if (xz_buf.out_pos != PAGE_SIZE)
+			break;
+	} while (xz_ret == XZ_OK);
+
+	err = fw_decompress_xz_error(dev, xz_ret);
+	if (!err)
+		err = fw_map_paged_buf(fw_priv);
+
+ out:
+	xz_dec_end(xz_dec);
+	return err;
+}
+
+static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
+			    size_t in_size, const void *in_buffer)
+{
+	/* if the buffer is pre-allocated, we can perform in single-shot mode */
+	if (fw_priv->data)
+		return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
+	else
+		return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
+}
+#endif /* CONFIG_FW_LOADER_COMPRESS */
+
+/* direct firmware loading support */
+static char fw_path_para[256];
+static const char * const fw_path[] = {
+	fw_path_para,
+	"/lib/firmware/updates/" UTS_RELEASE,
+	"/lib/firmware/updates",
+	"/lib/firmware/" UTS_RELEASE,
+	"/lib/firmware"
+};
+
+/*
+ * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
+ * from kernel command line because firmware_class is generally built in
+ * kernel instead of module.
+ */
+module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
+MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
+
+static int
+fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
+			   const char *suffix,
+			   int (*decompress)(struct device *dev,
+					     struct fw_priv *fw_priv,
+					     size_t in_size,
+					     const void *in_buffer))
+{
+	size_t size;
+	int i, len;
+	int rc = -ENOENT;
+	char *path;
+	size_t msize = INT_MAX;
+	void *buffer = NULL;
+
+	/* Already populated data member means we're loading into a buffer */
+	if (!decompress && fw_priv->data) {
+		buffer = fw_priv->data;
+		msize = fw_priv->allocated_size;
+	}
+
+	path = __getname();
+	if (!path)
+		return -ENOMEM;
+
+	for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
+		size_t file_size = 0;
+		size_t *file_size_ptr = NULL;
+
+		/* skip the unset customized path */
+		if (!fw_path[i][0])
+			continue;
+
+		len = snprintf(path, PATH_MAX, "%s/%s%s",
+			       fw_path[i], fw_priv->fw_name, suffix);
+		if (len >= PATH_MAX) {
+			rc = -ENAMETOOLONG;
+			break;
+		}
+
+		fw_priv->size = 0;
+
+		/*
+		 * The total file size is only examined when doing a partial
+		 * read; the "full read" case needs to fail if the whole
+		 * firmware was not completely loaded.
+		 */
+		if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
+			file_size_ptr = &file_size;
+
+		/* load firmware files from the mount namespace of init */
+		rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
+						       &buffer, msize,
+						       file_size_ptr,
+						       READING_FIRMWARE);
+		if (rc < 0) {
+			if (rc != -ENOENT)
+				dev_warn(device, "loading %s failed with error %d\n",
+					 path, rc);
+			else
+				dev_dbg(device, "loading %s failed for no such file or directory.\n",
+					 path);
+			continue;
+		}
+		size = rc;
+		rc = 0;
+
+		dev_dbg(device, "Loading firmware from %s\n", path);
+		if (decompress) {
+			dev_dbg(device, "f/w decompressing %s\n",
+				fw_priv->fw_name);
+			rc = decompress(device, fw_priv, size, buffer);
+			/* discard the superfluous original content */
+			vfree(buffer);
+			buffer = NULL;
+			if (rc) {
+				fw_free_paged_buf(fw_priv);
+				continue;
+			}
+		} else {
+			dev_dbg(device, "direct-loading %s\n",
+				fw_priv->fw_name);
+			if (!fw_priv->data)
+				fw_priv->data = buffer;
+			fw_priv->size = size;
+		}
+		fw_state_done(fw_priv);
+		break;
+	}
+	__putname(path);
+
+	return rc;
+}
+
+/* firmware holds the ownership of pages */
+static void firmware_free_data(const struct firmware *fw)
+{
+	/* Loaded directly? */
+	if (!fw->priv) {
+		vfree(fw->data);
+		return;
+	}
+	free_fw_priv(fw->priv);
+}
+
+/* store the pages buffer info firmware from buf */
+static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
+{
+	fw->priv = fw_priv;
+	fw->size = fw_priv->size;
+	fw->data = fw_priv->data;
+
+	pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
+		 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
+		 (unsigned int)fw_priv->size);
+}
+
+#ifdef CONFIG_FW_CACHE
+static void fw_name_devm_release(struct device *dev, void *res)
+{
+	struct fw_name_devm *fwn = res;
+
+	if (fwn->magic == (unsigned long)&fw_cache)
+		pr_debug("%s: fw_name-%s devm-%p released\n",
+				__func__, fwn->name, res);
+	kfree_const(fwn->name);
+}
+
+static int fw_devm_match(struct device *dev, void *res,
+		void *match_data)
+{
+	struct fw_name_devm *fwn = res;
+
+	return (fwn->magic == (unsigned long)&fw_cache) &&
+		!strcmp(fwn->name, match_data);
+}
+
+static struct fw_name_devm *fw_find_devm_name(struct device *dev,
+		const char *name)
+{
+	struct fw_name_devm *fwn;
+
+	fwn = devres_find(dev, fw_name_devm_release,
+			  fw_devm_match, (void *)name);
+	return fwn;
+}
+
+static bool fw_cache_is_setup(struct device *dev, const char *name)
+{
+	struct fw_name_devm *fwn;
+
+	fwn = fw_find_devm_name(dev, name);
+	if (fwn)
+		return true;
+
+	return false;
+}
+
+/* add firmware name into devres list */
+static int fw_add_devm_name(struct device *dev, const char *name)
+{
+	struct fw_name_devm *fwn;
+
+	if (fw_cache_is_setup(dev, name))
+		return 0;
+
+	fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
+			   GFP_KERNEL);
+	if (!fwn)
+		return -ENOMEM;
+	fwn->name = kstrdup_const(name, GFP_KERNEL);
+	if (!fwn->name) {
+		devres_free(fwn);
+		return -ENOMEM;
+	}
+
+	fwn->magic = (unsigned long)&fw_cache;
+	devres_add(dev, fwn);
+
+	return 0;
+}
+#else
+static bool fw_cache_is_setup(struct device *dev, const char *name)
+{
+	return false;
+}
+
+static int fw_add_devm_name(struct device *dev, const char *name)
+{
+	return 0;
+}
+#endif
+
+int assign_fw(struct firmware *fw, struct device *device)
+{
+	struct fw_priv *fw_priv = fw->priv;
+	int ret;
+
+	mutex_lock(&fw_lock);
+	if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
+		mutex_unlock(&fw_lock);
+		return -ENOENT;
+	}
+
+	/*
+	 * add firmware name into devres list so that we can auto cache
+	 * and uncache firmware for device.
+	 *
+	 * device may has been deleted already, but the problem
+	 * should be fixed in devres or driver core.
+	 */
+	/* don't cache firmware handled without uevent */
+	if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
+	    !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
+		ret = fw_add_devm_name(device, fw_priv->fw_name);
+		if (ret) {
+			mutex_unlock(&fw_lock);
+			return ret;
+		}
+	}
+
+	/*
+	 * After caching firmware image is started, let it piggyback
+	 * on request firmware.
+	 */
+	if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
+	    fw_priv->fwc->state == FW_LOADER_START_CACHE)
+		fw_cache_piggyback_on_request(fw_priv);
+
+	/* pass the pages buffer to driver at the last minute */
+	fw_set_page_data(fw_priv, fw);
+	mutex_unlock(&fw_lock);
+	return 0;
+}
+
+/* prepare firmware and firmware_buf structs;
+ * return 0 if a firmware is already assigned, 1 if need to load one,
+ * or a negative error code
+ */
+static int
+_request_firmware_prepare(struct firmware **firmware_p, const char *name,
+			  struct device *device, void *dbuf, size_t size,
+			  size_t offset, u32 opt_flags)
+{
+	struct firmware *firmware;
+	struct fw_priv *fw_priv;
+	int ret;
+
+	*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
+	if (!firmware) {
+		dev_err(device, "%s: kmalloc(struct firmware) failed\n",
+			__func__);
+		return -ENOMEM;
+	}
+
+	if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
+		dev_dbg(device, "using built-in %s\n", name);
+		return 0; /* assigned */
+	}
+
+	ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
+				   offset, opt_flags);
+
+	/*
+	 * bind with 'priv' now to avoid warning in failure path
+	 * of requesting firmware.
+	 */
+	firmware->priv = fw_priv;
+
+	if (ret > 0) {
+		ret = fw_state_wait(fw_priv);
+		if (!ret) {
+			fw_set_page_data(fw_priv, firmware);
+			return 0; /* assigned */
+		}
+	}
+
+	if (ret < 0)
+		return ret;
+	return 1; /* need to load */
+}
+
+/*
+ * Batched requests need only one wake, we need to do this step last due to the
+ * fallback mechanism. The buf is protected with kref_get(), and it won't be
+ * released until the last user calls release_firmware().
+ *
+ * Failed batched requests are possible as well, in such cases we just share
+ * the struct fw_priv and won't release it until all requests are woken
+ * and have gone through this same path.
+ */
+static void fw_abort_batch_reqs(struct firmware *fw)
+{
+	struct fw_priv *fw_priv;
+
+	/* Loaded directly? */
+	if (!fw || !fw->priv)
+		return;
+
+	fw_priv = fw->priv;
+	mutex_lock(&fw_lock);
+	if (!fw_state_is_aborted(fw_priv))
+		fw_state_aborted(fw_priv);
+	mutex_unlock(&fw_lock);
+}
+
+/* called from request_firmware() and request_firmware_work_func() */
+static int
+_request_firmware(const struct firmware **firmware_p, const char *name,
+		  struct device *device, void *buf, size_t size,
+		  size_t offset, u32 opt_flags)
+{
+	struct firmware *fw = NULL;
+	struct cred *kern_cred = NULL;
+	const struct cred *old_cred;
+	bool nondirect = false;
+	int ret;
+
+	if (!firmware_p)
+		return -EINVAL;
+
+	if (!name || name[0] == '\0') {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = _request_firmware_prepare(&fw, name, device, buf, size,
+					offset, opt_flags);
+	if (ret <= 0) /* error or already assigned */
+		goto out;
+
+	/*
+	 * We are about to try to access the firmware file. Because we may have been
+	 * called by a driver when serving an unrelated request from userland, we use
+	 * the kernel credentials to read the file.
+	 */
+	kern_cred = prepare_kernel_cred(NULL);
+	if (!kern_cred) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	old_cred = override_creds(kern_cred);
+
+	ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
+
+	/* Only full reads can support decompression, platform, and sysfs. */
+	if (!(opt_flags & FW_OPT_PARTIAL))
+		nondirect = true;
+
+#ifdef CONFIG_FW_LOADER_COMPRESS
+	if (ret == -ENOENT && nondirect)
+		ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
+						 fw_decompress_xz);
+#endif
+	if (ret == -ENOENT && nondirect)
+		ret = firmware_fallback_platform(fw->priv);
+
+	if (ret) {
+		if (!(opt_flags & FW_OPT_NO_WARN))
+			dev_warn(device,
+				 "Direct firmware load for %s failed with error %d\n",
+				 name, ret);
+		if (nondirect)
+			ret = firmware_fallback_sysfs(fw, name, device,
+						      opt_flags, ret);
+	} else
+		ret = assign_fw(fw, device);
+
+	revert_creds(old_cred);
+	put_cred(kern_cred);
+
+ out:
+	if (ret < 0) {
+		fw_abort_batch_reqs(fw);
+		release_firmware(fw);
+		fw = NULL;
+	}
+
+	*firmware_p = fw;
+	return ret;
+}
+
+/**
+ * request_firmware() - send firmware request and wait for it
+ * @firmware_p: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded
+ *
+ *      @firmware_p will be used to return a firmware image by the name
+ *      of @name for device @device.
+ *
+ *      Should be called from user context where sleeping is allowed.
+ *
+ *      @name will be used as $FIRMWARE in the uevent environment and
+ *      should be distinctive enough not to be confused with any other
+ *      firmware image for this or any other device.
+ *
+ *	Caller must hold the reference count of @device.
+ *
+ *	The function can be called safely inside device's suspend and
+ *	resume callback.
+ **/
+int
+request_firmware(const struct firmware **firmware_p, const char *name,
+		 struct device *device)
+{
+	int ret;
+
+	/* Need to pin this module until return */
+	__module_get(THIS_MODULE);
+	ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
+				FW_OPT_UEVENT);
+	module_put(THIS_MODULE);
+	return ret;
+}
+EXPORT_SYMBOL(request_firmware);
+
+/**
+ * firmware_request_nowarn() - request for an optional fw module
+ * @firmware: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded
+ *
+ * This function is similar in behaviour to request_firmware(), except it
+ * doesn't produce warning messages when the file is not found. The sysfs
+ * fallback mechanism is enabled if direct filesystem lookup fails. However,
+ * failures to find the firmware file with it are still suppressed. It is
+ * therefore up to the driver to check for the return value of this call and to
+ * decide when to inform the users of errors.
+ **/
+int firmware_request_nowarn(const struct firmware **firmware, const char *name,
+			    struct device *device)
+{
+	int ret;
+
+	/* Need to pin this module until return */
+	__module_get(THIS_MODULE);
+	ret = _request_firmware(firmware, name, device, NULL, 0, 0,
+				FW_OPT_UEVENT | FW_OPT_NO_WARN);
+	module_put(THIS_MODULE);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(firmware_request_nowarn);
+
+/**
+ * request_firmware_direct() - load firmware directly without usermode helper
+ * @firmware_p: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded
+ *
+ * This function works pretty much like request_firmware(), but this doesn't
+ * fall back to usermode helper even if the firmware couldn't be loaded
+ * directly from fs.  Hence it's useful for loading optional firmwares, which
+ * aren't always present, without extra long timeouts of udev.
+ **/
+int request_firmware_direct(const struct firmware **firmware_p,
+			    const char *name, struct device *device)
+{
+	int ret;
+
+	__module_get(THIS_MODULE);
+	ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
+				FW_OPT_UEVENT | FW_OPT_NO_WARN |
+				FW_OPT_NOFALLBACK_SYSFS);
+	module_put(THIS_MODULE);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(request_firmware_direct);
+
+/**
+ * firmware_request_platform() - request firmware with platform-fw fallback
+ * @firmware: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded
+ *
+ * This function is similar in behaviour to request_firmware, except that if
+ * direct filesystem lookup fails, it will fallback to looking for a copy of the
+ * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
+ **/
+int firmware_request_platform(const struct firmware **firmware,
+			      const char *name, struct device *device)
+{
+	int ret;
+
+	/* Need to pin this module until return */
+	__module_get(THIS_MODULE);
+	ret = _request_firmware(firmware, name, device, NULL, 0, 0,
+				FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
+	module_put(THIS_MODULE);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(firmware_request_platform);
+
+/**
+ * firmware_request_cache() - cache firmware for suspend so resume can use it
+ * @name: name of firmware file
+ * @device: device for which firmware should be cached for
+ *
+ * There are some devices with an optimization that enables the device to not
+ * require loading firmware on system reboot. This optimization may still
+ * require the firmware present on resume from suspend. This routine can be
+ * used to ensure the firmware is present on resume from suspend in these
+ * situations. This helper is not compatible with drivers which use
+ * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
+ **/
+int firmware_request_cache(struct device *device, const char *name)
+{
+	int ret;
+
+	mutex_lock(&fw_lock);
+	ret = fw_add_devm_name(device, name);
+	mutex_unlock(&fw_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(firmware_request_cache);
+
+/**
+ * request_firmware_into_buf() - load firmware into a previously allocated buffer
+ * @firmware_p: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded and DMA region allocated
+ * @buf: address of buffer to load firmware into
+ * @size: size of buffer
+ *
+ * This function works pretty much like request_firmware(), but it doesn't
+ * allocate a buffer to hold the firmware data. Instead, the firmware
+ * is loaded directly into the buffer pointed to by @buf and the @firmware_p
+ * data member is pointed at @buf.
+ *
+ * This function doesn't cache firmware either.
+ */
+int
+request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
+			  struct device *device, void *buf, size_t size)
+{
+	int ret;
+
+	if (fw_cache_is_setup(device, name))
+		return -EOPNOTSUPP;
+
+	__module_get(THIS_MODULE);
+	ret = _request_firmware(firmware_p, name, device, buf, size, 0,
+				FW_OPT_UEVENT | FW_OPT_NOCACHE);
+	module_put(THIS_MODULE);
+	return ret;
+}
+EXPORT_SYMBOL(request_firmware_into_buf);
+
+/**
+ * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
+ * @firmware_p: pointer to firmware image
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded and DMA region allocated
+ * @buf: address of buffer to load firmware into
+ * @size: size of buffer
+ * @offset: offset into file to read
+ *
+ * This function works pretty much like request_firmware_into_buf except
+ * it allows a partial read of the file.
+ */
+int
+request_partial_firmware_into_buf(const struct firmware **firmware_p,
+				  const char *name, struct device *device,
+				  void *buf, size_t size, size_t offset)
+{
+	int ret;
+
+	if (fw_cache_is_setup(device, name))
+		return -EOPNOTSUPP;
+
+	__module_get(THIS_MODULE);
+	ret = _request_firmware(firmware_p, name, device, buf, size, offset,
+				FW_OPT_UEVENT | FW_OPT_NOCACHE |
+				FW_OPT_PARTIAL);
+	module_put(THIS_MODULE);
+	return ret;
+}
+EXPORT_SYMBOL(request_partial_firmware_into_buf);
+
+/**
+ * release_firmware() - release the resource associated with a firmware image
+ * @fw: firmware resource to release
+ **/
+void release_firmware(const struct firmware *fw)
+{
+	if (fw) {
+		if (!fw_is_builtin_firmware(fw))
+			firmware_free_data(fw);
+		kfree(fw);
+	}
+}
+EXPORT_SYMBOL(release_firmware);
+
+/* Async support */
+struct firmware_work {
+	struct work_struct work;
+	struct module *module;
+	const char *name;
+	struct device *device;
+	void *context;
+	void (*cont)(const struct firmware *fw, void *context);
+	u32 opt_flags;
+};
+
+static void request_firmware_work_func(struct work_struct *work)
+{
+	struct firmware_work *fw_work;
+	const struct firmware *fw;
+
+	fw_work = container_of(work, struct firmware_work, work);
+
+	_request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
+			  fw_work->opt_flags);
+	fw_work->cont(fw, fw_work->context);
+	put_device(fw_work->device); /* taken in request_firmware_nowait() */
+
+	module_put(fw_work->module);
+	kfree_const(fw_work->name);
+	kfree(fw_work);
+}
+
+/**
+ * request_firmware_nowait() - asynchronous version of request_firmware
+ * @module: module requesting the firmware
+ * @uevent: sends uevent to copy the firmware image if this flag
+ *	is non-zero else the firmware copy must be done manually.
+ * @name: name of firmware file
+ * @device: device for which firmware is being loaded
+ * @gfp: allocation flags
+ * @context: will be passed over to @cont, and
+ *	@fw may be %NULL if firmware request fails.
+ * @cont: function will be called asynchronously when the firmware
+ *	request is over.
+ *
+ *	Caller must hold the reference count of @device.
+ *
+ *	Asynchronous variant of request_firmware() for user contexts:
+ *		- sleep for as small periods as possible since it may
+ *		  increase kernel boot time of built-in device drivers
+ *		  requesting firmware in their ->probe() methods, if
+ *		  @gfp is GFP_KERNEL.
+ *
+ *		- can't sleep at all if @gfp is GFP_ATOMIC.
+ **/
+int
+request_firmware_nowait(
+	struct module *module, bool uevent,
+	const char *name, struct device *device, gfp_t gfp, void *context,
+	void (*cont)(const struct firmware *fw, void *context))
+{
+	struct firmware_work *fw_work;
+
+	fw_work = kzalloc(sizeof(struct firmware_work), gfp);
+	if (!fw_work)
+		return -ENOMEM;
+
+	fw_work->module = module;
+	fw_work->name = kstrdup_const(name, gfp);
+	if (!fw_work->name) {
+		kfree(fw_work);
+		return -ENOMEM;
+	}
+	fw_work->device = device;
+	fw_work->context = context;
+	fw_work->cont = cont;
+	fw_work->opt_flags = FW_OPT_NOWAIT |
+		(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
+
+	if (!uevent && fw_cache_is_setup(device, name)) {
+		kfree_const(fw_work->name);
+		kfree(fw_work);
+		return -EOPNOTSUPP;
+	}
+
+	if (!try_module_get(module)) {
+		kfree_const(fw_work->name);
+		kfree(fw_work);
+		return -EFAULT;
+	}
+
+	get_device(fw_work->device);
+	INIT_WORK(&fw_work->work, request_firmware_work_func);
+	schedule_work(&fw_work->work);
+	return 0;
+}
+EXPORT_SYMBOL(request_firmware_nowait);
+
+#ifdef CONFIG_FW_CACHE
+static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
+
+/**
+ * cache_firmware() - cache one firmware image in kernel memory space
+ * @fw_name: the firmware image name
+ *
+ * Cache firmware in kernel memory so that drivers can use it when
+ * system isn't ready for them to request firmware image from userspace.
+ * Once it returns successfully, driver can use request_firmware or its
+ * nowait version to get the cached firmware without any interacting
+ * with userspace
+ *
+ * Return 0 if the firmware image has been cached successfully
+ * Return !0 otherwise
+ *
+ */
+static int cache_firmware(const char *fw_name)
+{
+	int ret;
+	const struct firmware *fw;
+
+	pr_debug("%s: %s\n", __func__, fw_name);
+
+	ret = request_firmware(&fw, fw_name, NULL);
+	if (!ret)
+		kfree(fw);
+
+	pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
+
+	return ret;
+}
+
+static struct fw_priv *lookup_fw_priv(const char *fw_name)
+{
+	struct fw_priv *tmp;
+	struct firmware_cache *fwc = &fw_cache;
+
+	spin_lock(&fwc->lock);
+	tmp = __lookup_fw_priv(fw_name);
+	spin_unlock(&fwc->lock);
+
+	return tmp;
+}
+
+/**
+ * uncache_firmware() - remove one cached firmware image
+ * @fw_name: the firmware image name
+ *
+ * Uncache one firmware image which has been cached successfully
+ * before.
+ *
+ * Return 0 if the firmware cache has been removed successfully
+ * Return !0 otherwise
+ *
+ */
+static int uncache_firmware(const char *fw_name)
+{
+	struct fw_priv *fw_priv;
+	struct firmware fw;
+
+	pr_debug("%s: %s\n", __func__, fw_name);
+
+	if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
+		return 0;
+
+	fw_priv = lookup_fw_priv(fw_name);
+	if (fw_priv) {
+		free_fw_priv(fw_priv);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
+{
+	struct fw_cache_entry *fce;
+
+	fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
+	if (!fce)
+		goto exit;
+
+	fce->name = kstrdup_const(name, GFP_ATOMIC);
+	if (!fce->name) {
+		kfree(fce);
+		fce = NULL;
+		goto exit;
+	}
+exit:
+	return fce;
+}
+
+static int __fw_entry_found(const char *name)
+{
+	struct firmware_cache *fwc = &fw_cache;
+	struct fw_cache_entry *fce;
+
+	list_for_each_entry(fce, &fwc->fw_names, list) {
+		if (!strcmp(fce->name, name))
+			return 1;
+	}
+	return 0;
+}
+
+static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
+{
+	const char *name = fw_priv->fw_name;
+	struct firmware_cache *fwc = fw_priv->fwc;
+	struct fw_cache_entry *fce;
+
+	spin_lock(&fwc->name_lock);
+	if (__fw_entry_found(name))
+		goto found;
+
+	fce = alloc_fw_cache_entry(name);
+	if (fce) {
+		list_add(&fce->list, &fwc->fw_names);
+		kref_get(&fw_priv->ref);
+		pr_debug("%s: fw: %s\n", __func__, name);
+	}
+found:
+	spin_unlock(&fwc->name_lock);
+}
+
+static void free_fw_cache_entry(struct fw_cache_entry *fce)
+{
+	kfree_const(fce->name);
+	kfree(fce);
+}
+
+static void __async_dev_cache_fw_image(void *fw_entry,
+				       async_cookie_t cookie)
+{
+	struct fw_cache_entry *fce = fw_entry;
+	struct firmware_cache *fwc = &fw_cache;
+	int ret;
+
+	ret = cache_firmware(fce->name);
+	if (ret) {
+		spin_lock(&fwc->name_lock);
+		list_del(&fce->list);
+		spin_unlock(&fwc->name_lock);
+
+		free_fw_cache_entry(fce);
+	}
+}
+
+/* called with dev->devres_lock held */
+static void dev_create_fw_entry(struct device *dev, void *res,
+				void *data)
+{
+	struct fw_name_devm *fwn = res;
+	const char *fw_name = fwn->name;
+	struct list_head *head = data;
+	struct fw_cache_entry *fce;
+
+	fce = alloc_fw_cache_entry(fw_name);
+	if (fce)
+		list_add(&fce->list, head);
+}
+
+static int devm_name_match(struct device *dev, void *res,
+			   void *match_data)
+{
+	struct fw_name_devm *fwn = res;
+	return (fwn->magic == (unsigned long)match_data);
+}
+
+static void dev_cache_fw_image(struct device *dev, void *data)
+{
+	LIST_HEAD(todo);
+	struct fw_cache_entry *fce;
+	struct fw_cache_entry *fce_next;
+	struct firmware_cache *fwc = &fw_cache;
+
+	devres_for_each_res(dev, fw_name_devm_release,
+			    devm_name_match, &fw_cache,
+			    dev_create_fw_entry, &todo);
+
+	list_for_each_entry_safe(fce, fce_next, &todo, list) {
+		list_del(&fce->list);
+
+		spin_lock(&fwc->name_lock);
+		/* only one cache entry for one firmware */
+		if (!__fw_entry_found(fce->name)) {
+			list_add(&fce->list, &fwc->fw_names);
+		} else {
+			free_fw_cache_entry(fce);
+			fce = NULL;
+		}
+		spin_unlock(&fwc->name_lock);
+
+		if (fce)
+			async_schedule_domain(__async_dev_cache_fw_image,
+					      (void *)fce,
+					      &fw_cache_domain);
+	}
+}
+
+static void __device_uncache_fw_images(void)
+{
+	struct firmware_cache *fwc = &fw_cache;
+	struct fw_cache_entry *fce;
+
+	spin_lock(&fwc->name_lock);
+	while (!list_empty(&fwc->fw_names)) {
+		fce = list_entry(fwc->fw_names.next,
+				struct fw_cache_entry, list);
+		list_del(&fce->list);
+		spin_unlock(&fwc->name_lock);
+
+		uncache_firmware(fce->name);
+		free_fw_cache_entry(fce);
+
+		spin_lock(&fwc->name_lock);
+	}
+	spin_unlock(&fwc->name_lock);
+}
+
+/**
+ * device_cache_fw_images() - cache devices' firmware
+ *
+ * If one device called request_firmware or its nowait version
+ * successfully before, the firmware names are recored into the
+ * device's devres link list, so device_cache_fw_images can call
+ * cache_firmware() to cache these firmwares for the device,
+ * then the device driver can load its firmwares easily at
+ * time when system is not ready to complete loading firmware.
+ */
+static void device_cache_fw_images(void)
+{
+	struct firmware_cache *fwc = &fw_cache;
+	DEFINE_WAIT(wait);
+
+	pr_debug("%s\n", __func__);
+
+	/* cancel uncache work */
+	cancel_delayed_work_sync(&fwc->work);
+
+	fw_fallback_set_cache_timeout();
+
+	mutex_lock(&fw_lock);
+	fwc->state = FW_LOADER_START_CACHE;
+	dpm_for_each_dev(NULL, dev_cache_fw_image);
+	mutex_unlock(&fw_lock);
+
+	/* wait for completion of caching firmware for all devices */
+	async_synchronize_full_domain(&fw_cache_domain);
+
+	fw_fallback_set_default_timeout();
+}
+
+/**
+ * device_uncache_fw_images() - uncache devices' firmware
+ *
+ * uncache all firmwares which have been cached successfully
+ * by device_uncache_fw_images earlier
+ */
+static void device_uncache_fw_images(void)
+{
+	pr_debug("%s\n", __func__);
+	__device_uncache_fw_images();
+}
+
+static void device_uncache_fw_images_work(struct work_struct *work)
+{
+	device_uncache_fw_images();
+}
+
+/**
+ * device_uncache_fw_images_delay() - uncache devices firmwares
+ * @delay: number of milliseconds to delay uncache device firmwares
+ *
+ * uncache all devices's firmwares which has been cached successfully
+ * by device_cache_fw_images after @delay milliseconds.
+ */
+static void device_uncache_fw_images_delay(unsigned long delay)
+{
+	queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
+			   msecs_to_jiffies(delay));
+}
+
+static int fw_pm_notify(struct notifier_block *notify_block,
+			unsigned long mode, void *unused)
+{
+	switch (mode) {
+	case PM_HIBERNATION_PREPARE:
+	case PM_SUSPEND_PREPARE:
+	case PM_RESTORE_PREPARE:
+		/*
+		 * kill pending fallback requests with a custom fallback
+		 * to avoid stalling suspend.
+		 */
+		kill_pending_fw_fallback_reqs(true);
+		device_cache_fw_images();
+		break;
+
+	case PM_POST_SUSPEND:
+	case PM_POST_HIBERNATION:
+	case PM_POST_RESTORE:
+		/*
+		 * In case that system sleep failed and syscore_suspend is
+		 * not called.
+		 */
+		mutex_lock(&fw_lock);
+		fw_cache.state = FW_LOADER_NO_CACHE;
+		mutex_unlock(&fw_lock);
+
+		device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
+		break;
+	}
+
+	return 0;
+}
+
+/* stop caching firmware once syscore_suspend is reached */
+static int fw_suspend(void)
+{
+	fw_cache.state = FW_LOADER_NO_CACHE;
+	return 0;
+}
+
+static struct syscore_ops fw_syscore_ops = {
+	.suspend = fw_suspend,
+};
+
+static int __init register_fw_pm_ops(void)
+{
+	int ret;
+
+	spin_lock_init(&fw_cache.name_lock);
+	INIT_LIST_HEAD(&fw_cache.fw_names);
+
+	INIT_DELAYED_WORK(&fw_cache.work,
+			  device_uncache_fw_images_work);
+
+	fw_cache.pm_notify.notifier_call = fw_pm_notify;
+	ret = register_pm_notifier(&fw_cache.pm_notify);
+	if (ret)
+		return ret;
+
+	register_syscore_ops(&fw_syscore_ops);
+
+	return ret;
+}
+
+static inline void unregister_fw_pm_ops(void)
+{
+	unregister_syscore_ops(&fw_syscore_ops);
+	unregister_pm_notifier(&fw_cache.pm_notify);
+}
+#else
+static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
+{
+}
+static inline int register_fw_pm_ops(void)
+{
+	return 0;
+}
+static inline void unregister_fw_pm_ops(void)
+{
+}
+#endif
+
+static void __init fw_cache_init(void)
+{
+	spin_lock_init(&fw_cache.lock);
+	INIT_LIST_HEAD(&fw_cache.head);
+	fw_cache.state = FW_LOADER_NO_CACHE;
+}
+
+static int fw_shutdown_notify(struct notifier_block *unused1,
+			      unsigned long unused2, void *unused3)
+{
+	/*
+	 * Kill all pending fallback requests to avoid both stalling shutdown,
+	 * and avoid a deadlock with the usermode_lock.
+	 */
+	kill_pending_fw_fallback_reqs(false);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block fw_shutdown_nb = {
+	.notifier_call = fw_shutdown_notify,
+};
+
+static int __init firmware_class_init(void)
+{
+	int ret;
+
+	/* No need to unfold these on exit */
+	fw_cache_init();
+
+	ret = register_fw_pm_ops();
+	if (ret)
+		return ret;
+
+	ret = register_reboot_notifier(&fw_shutdown_nb);
+	if (ret)
+		goto out;
+
+	return register_sysfs_loader();
+
+out:
+	unregister_fw_pm_ops();
+	return ret;
+}
+
+static void __exit firmware_class_exit(void)
+{
+	unregister_fw_pm_ops();
+	unregister_reboot_notifier(&fw_shutdown_nb);
+	unregister_sysfs_loader();
+}
+
+fs_initcall(firmware_class_init);
+module_exit(firmware_class_exit);