[RFC PATCH 3/5] firmware_loader: Split fw_sysfs support from fallback
From: Russ Weight
Date: Thu Feb 03 2022 - 16:31:19 EST
In preparation for sharing the "loading" and "data" sysfs nodes with the
new firmware upload support, split out sysfs functionality from fallback.c
and fallback.h into fw_sysfs.c and fw_sysfs.h. This includes the firmware
class driver code that is associated with the sysfs files and the
fw_fallback_config support for the timeout sysfs node.
CONFIG_FW_LOADER_SYSFS is created and is selected by
CONFIG_FW_LOADER_USER_HELPER in order to include fw_sysfs.o in
firmware_class-objs.
This is mostly just a code reorganization. There are a few symbols that
change in scope, and these can be identified by looking at the header
file changes. A few white-space warnings from checkpatch are also
addressed in this patch.
Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
---
drivers/base/firmware_loader/Kconfig | 4 +
drivers/base/firmware_loader/Makefile | 1 +
drivers/base/firmware_loader/fallback.c | 430 ------------------------
drivers/base/firmware_loader/fallback.h | 46 +--
drivers/base/firmware_loader/fw_sysfs.c | 413 +++++++++++++++++++++++
drivers/base/firmware_loader/fw_sysfs.h | 94 ++++++
6 files changed, 513 insertions(+), 475 deletions(-)
create mode 100644 drivers/base/firmware_loader/fw_sysfs.c
create mode 100644 drivers/base/firmware_loader/fw_sysfs.h
diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig
index 5b24f3959255..1bfe18900ed5 100644
--- a/drivers/base/firmware_loader/Kconfig
+++ b/drivers/base/firmware_loader/Kconfig
@@ -29,6 +29,9 @@ if FW_LOADER
config FW_LOADER_PAGED_BUF
bool
+config FW_LOADER_SYSFS
+ bool
+
config EXTRA_FIRMWARE
string "Build named firmware blobs into the kernel binary"
help
@@ -70,6 +73,7 @@ config EXTRA_FIRMWARE_DIR
config FW_LOADER_USER_HELPER
bool "Enable the firmware sysfs fallback mechanism"
+ select FW_LOADER_SYSFS
select FW_LOADER_PAGED_BUF
help
This option enables a sysfs loading facility to enable firmware
diff --git a/drivers/base/firmware_loader/Makefile b/drivers/base/firmware_loader/Makefile
index e87843408fe6..787c833d0c6e 100644
--- a/drivers/base/firmware_loader/Makefile
+++ b/drivers/base/firmware_loader/Makefile
@@ -6,5 +6,6 @@ obj-$(CONFIG_FW_LOADER) += firmware_class.o
firmware_class-objs := main.o
firmware_class-$(CONFIG_FW_LOADER_USER_HELPER) += fallback.o
firmware_class-$(CONFIG_EFI_EMBEDDED_FIRMWARE) += fallback_platform.o
+firmware_class-$(CONFIG_FW_LOADER_SYSFS) += fw_sysfs.o
obj-y += builtin/
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index d82e055a4297..bf68e3947814 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -3,12 +3,9 @@
#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"
@@ -18,22 +15,6 @@
* 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
@@ -58,52 +39,11 @@ static long firmware_loading_timeout(void)
__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)
@@ -120,376 +60,6 @@ void kill_pending_fw_fallback_reqs(bool only_kill_custom)
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());
-}
-
-/**
- * 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)
-{
- int ret = class_register(&firmware_class);
-
- if (ret != 0)
- return ret;
- return register_firmware_config_sysctl();
-}
-
-void unregister_sysfs_loader(void)
-{
- unregister_firmware_config_sysctl();
- 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) || fw_state_is_done(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
diff --git a/drivers/base/firmware_loader/fallback.h b/drivers/base/firmware_loader/fallback.h
index 9f3055d3b4ca..52adc5a0bf52 100644
--- a/drivers/base/firmware_loader/fallback.h
+++ b/drivers/base/firmware_loader/fallback.h
@@ -6,29 +6,7 @@
#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;
-};
+#include "fw_sysfs.h"
#ifdef CONFIG_FW_LOADER_USER_HELPER
int firmware_fallback_sysfs(struct firmware *fw, const char *name,
@@ -40,19 +18,6 @@ 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);
-#ifdef CONFIG_SYSCTL
-extern int register_firmware_config_sysctl(void);
-extern void unregister_firmware_config_sysctl(void);
-#else
-static inline int register_firmware_config_sysctl(void)
-{
- return 0;
-}
-static inline void unregister_firmware_config_sysctl(void) { }
-#endif /* CONFIG_SYSCTL */
-
#else /* CONFIG_FW_LOADER_USER_HELPER */
static inline int firmware_fallback_sysfs(struct firmware *fw, const char *name,
struct device *device,
@@ -66,15 +31,6 @@ static inline int firmware_fallback_sysfs(struct firmware *fw, const char *name,
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
diff --git a/drivers/base/firmware_loader/fw_sysfs.c b/drivers/base/firmware_loader/fw_sysfs.c
new file mode 100644
index 000000000000..70cb1d67ffb2
--- /dev/null
+++ b/drivers/base/firmware_loader/fw_sysfs.c
@@ -0,0 +1,413 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/security.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "firmware.h"
+#include "fw_sysfs.h"
+
+/*
+ * sysfs support for firmware loader
+ */
+
+MODULE_IMPORT_NS(FIRMWARE_LOADER_PRIVATE);
+
+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);
+}
+
+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 ssize_t timeout_show(struct class *class, struct class_attribute *attr,
+ char *buf)
+{
+ return sysfs_emit(buf, "%d\n", __firmware_loading_timeout());
+}
+
+/**
+ * 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);
+}
+
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+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;
+}
+#endif /* CONFIG_FW_LOADER_USER_HELPER */
+
+static struct class firmware_class = {
+ .name = "firmware",
+ .class_groups = firmware_class_groups,
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+ .dev_uevent = firmware_uevent,
+#endif
+ .dev_release = fw_dev_release,
+};
+
+int register_sysfs_loader(void)
+{
+ int ret = class_register(&firmware_class);
+
+ if (ret != 0)
+ return ret;
+ return register_firmware_config_sysctl();
+}
+
+void unregister_sysfs_loader(void)
+{
+ unregister_firmware_config_sysctl();
+ 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) || fw_state_is_done(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
+};
+
+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;
+}
diff --git a/drivers/base/firmware_loader/fw_sysfs.h b/drivers/base/firmware_loader/fw_sysfs.h
new file mode 100644
index 000000000000..0ca7f72892b0
--- /dev/null
+++ b/drivers/base/firmware_loader/fw_sysfs.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __FIRMWARE_SYSFS_H
+#define __FIRMWARE_SYSFS_H
+
+#include <linux/device.h>
+
+extern struct firmware_fallback_config fw_fallback_config;
+
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+/**
+ * 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;
+};
+
+int register_sysfs_loader(void);
+void unregister_sysfs_loader(void);
+#ifdef CONFIG_SYSCTL
+int register_firmware_config_sysctl(void);
+void unregister_firmware_config_sysctl(void);
+#else
+static inline int register_firmware_config_sysctl(void)
+{
+ return 0;
+}
+
+static inline void unregister_firmware_config_sysctl(void) { }
+#endif /* CONFIG_SYSCTL */
+#else /* CONFIG_FW_LOADER_USER_HELPER */
+static inline int register_sysfs_loader(void)
+{
+ return 0;
+}
+
+static inline void unregister_sysfs_loader(void)
+{
+}
+#endif /* CONFIG_FW_LOADER_USER_HELPER */
+
+struct fw_sysfs {
+ bool nowait;
+ struct device dev;
+ struct fw_priv *fw_priv;
+ struct firmware *fw;
+};
+
+static inline struct fw_sysfs *to_fw_sysfs(struct device *dev)
+{
+ return container_of(dev, struct fw_sysfs, dev);
+}
+
+/* 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 inline void __fw_fallback_set_timeout(int timeout)
+{
+ fw_fallback_config.loading_timeout = timeout;
+}
+
+void __fw_load_abort(struct fw_priv *fw_priv);
+
+static inline void fw_load_abort(struct fw_sysfs *fw_sysfs)
+{
+ struct fw_priv *fw_priv = fw_sysfs->fw_priv;
+
+ __fw_load_abort(fw_priv);
+}
+
+struct fw_sysfs *
+fw_create_instance(struct firmware *firmware, const char *fw_name,
+ struct device *device, u32 opt_flags);
+
+#endif /* __FIRMWARE_SYSFS_H */
--
2.25.1