v4.19.13 snapshot.
diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig
new file mode 100644
index 0000000..eb15d97
--- /dev/null
+++ b/drivers/base/firmware_loader/Kconfig
@@ -0,0 +1,154 @@
+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 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"
+ 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.
+
+endif # FW_LOADER
+endmenu
diff --git a/drivers/base/firmware_loader/Makefile b/drivers/base/firmware_loader/Makefile
new file mode 100644
index 0000000..a97eeb0
--- /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 0000000..b5c865f
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback.c
@@ -0,0 +1,702 @@
+// 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);
+}
+
+/* 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(array_size(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, enum fw_opt 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
+ * @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,
+ enum fw_opt 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,
+ enum fw_opt 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(enum fw_opt 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(enum fw_opt 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))
+ return false;
+
+ /* Also permit LSMs and IMA to fail firmware sysfs fallback */
+ ret = security_kernel_load_data(LOADING_FIRMWARE);
+ if (ret < 0)
+ return ret;
+
+ 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
+ * @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 syfs
+ * loading interface. This syfs fallback mechanism may be disabled completely
+ * on a system by setting the proc sysctl value ignore_sysfs_fallback to true.
+ * If this false we check if the internal API caller set the @FW_OPT_NOFALLBACK
+ * flag, if so it would also disable the fallback mechanism. A system may want
+ * to enfoce 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,
+ enum fw_opt 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 syfs 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 0000000..2106350
--- /dev/null
+++ b/drivers/base/firmware_loader/fallback.h
@@ -0,0 +1,69 @@
+/* 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,
+ enum fw_opt 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,
+ enum fw_opt 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 0000000..7428659
--- /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 0000000..4c1395f
--- /dev/null
+++ b/drivers/base/firmware_loader/firmware.h
@@ -0,0 +1,136 @@
+/* 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: Disable the fallback mechanism. Takes precedence over
+ * &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
+ */
+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 = BIT(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,
+ enum fw_opt opt_flags);
+
+#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 0000000..8e9213b
--- /dev/null
+++ b/drivers/base/firmware_loader/main.c
@@ -0,0 +1,1279 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * main.c - Multi purpose firmware loading support
+ *
+ * Copyright (c) 2003 Manuel Estrada Sainz
+ *
+ * Please see Documentation/firmware_class/ for more information.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/capability.h>
+#include <linux/device.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 <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_PM_SLEEP
+ /*
+ * 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 void fw_copy_to_prealloc_buf(struct firmware *fw,
+ void *buf, size_t size)
+{
+ if (!buf || size < fw->size)
+ return;
+ memcpy(buf, fw->data, fw->size);
+}
+
+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;
+ fw_copy_to_prealloc_buf(fw, buf, size);
+
+ return true;
+ }
+ }
+
+ 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 int fw_cache_piggyback_on_request(const char *name);
+
+static struct fw_priv *__allocate_fw_priv(const char *fw_name,
+ struct firmware_cache *fwc,
+ void *dbuf, size_t size)
+{
+ struct fw_priv *fw_priv;
+
+ 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_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, enum fw_opt opt_flags)
+{
+ struct fw_priv *tmp;
+
+ spin_lock(&fwc->lock);
+ if (!(opt_flags & FW_OPT_NOCACHE)) {
+ 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);
+ 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);
+
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+ if (fw_priv->is_paged_buf) {
+ int i;
+ vunmap(fw_priv->data);
+ for (i = 0; i < fw_priv->nr_pages; i++)
+ __free_page(fw_priv->pages[i]);
+ vfree(fw_priv->pages);
+ } else
+#endif
+ 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);
+}
+
+/* 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)
+{
+ loff_t size;
+ int i, len;
+ int rc = -ENOENT;
+ char *path;
+ enum kernel_read_file_id id = READING_FIRMWARE;
+ size_t msize = INT_MAX;
+
+ /* Already populated data member means we're loading into a buffer */
+ if (fw_priv->data) {
+ id = READING_FIRMWARE_PREALLOC_BUFFER;
+ msize = fw_priv->allocated_size;
+ }
+
+ path = __getname();
+ if (!path)
+ return -ENOMEM;
+
+ for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
+ /* skip the unset customized path */
+ if (!fw_path[i][0])
+ continue;
+
+ len = snprintf(path, PATH_MAX, "%s/%s",
+ fw_path[i], fw_priv->fw_name);
+ if (len >= PATH_MAX) {
+ rc = -ENAMETOOLONG;
+ break;
+ }
+
+ fw_priv->size = 0;
+ rc = kernel_read_file_from_path(path, &fw_priv->data, &size,
+ msize, id);
+ if (rc) {
+ if (rc == -ENOENT)
+ dev_dbg(device, "loading %s failed with error %d\n",
+ path, rc);
+ else
+ dev_warn(device, "loading %s failed with error %d\n",
+ path, rc);
+ continue;
+ }
+ dev_dbg(device, "direct-loading %s\n", fw_priv->fw_name);
+ 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;
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+ fw->pages = fw_priv->pages;
+#endif
+ 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_PM_SLEEP
+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,
+ enum fw_opt opt_flags)
+{
+ 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 && (opt_flags & FW_OPT_UEVENT) &&
+ !(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 (!(opt_flags & FW_OPT_NOCACHE) &&
+ fw_priv->fwc->state == FW_LOADER_START_CACHE) {
+ if (fw_cache_piggyback_on_request(fw_priv->fw_name))
+ kref_get(&fw_priv->ref);
+ }
+
+ /* 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,
+ enum fw_opt 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,
+ 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;
+ if (!fw_state_is_aborted(fw_priv))
+ fw_state_aborted(fw_priv);
+}
+
+/* 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,
+ enum fw_opt opt_flags)
+{
+ struct firmware *fw = NULL;
+ 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,
+ opt_flags);
+ if (ret <= 0) /* error or already assigned */
+ goto out;
+
+ ret = fw_get_filesystem_firmware(device, 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);
+ ret = firmware_fallback_sysfs(fw, name, device, opt_flags, ret);
+ } else
+ ret = assign_fw(fw, device, opt_flags);
+
+ 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,
+ 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, 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,
+ 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,
+ FW_OPT_UEVENT | FW_OPT_NO_WARN |
+ FW_OPT_NOFALLBACK);
+ module_put(THIS_MODULE);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(request_firmware_direct);
+
+/**
+ * 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,
+ FW_OPT_UEVENT | FW_OPT_NOCACHE);
+ module_put(THIS_MODULE);
+ return ret;
+}
+EXPORT_SYMBOL(request_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);
+ enum fw_opt 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,
+ 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_PM_SLEEP
+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 int fw_cache_piggyback_on_request(const char *name)
+{
+ struct firmware_cache *fwc = &fw_cache;
+ struct fw_cache_entry *fce;
+ int ret = 0;
+
+ spin_lock(&fwc->name_lock);
+ if (__fw_entry_found(name))
+ goto found;
+
+ fce = alloc_fw_cache_entry(name);
+ if (fce) {
+ ret = 1;
+ list_add(&fce->list, &fwc->fw_names);
+ pr_debug("%s: fw: %s\n", __func__, name);
+ }
+found:
+ spin_unlock(&fwc->name_lock);
+ return ret;
+}
+
+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 int fw_cache_piggyback_on_request(const char *name)
+{
+ return 0;
+}
+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);