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path: root/drivers/base/firmware_loader/sysfs.c
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Diffstat (limited to 'drivers/base/firmware_loader/sysfs.c')
-rw-r--r--drivers/base/firmware_loader/sysfs.c419
1 files changed, 419 insertions, 0 deletions
diff --git a/drivers/base/firmware_loader/sysfs.c b/drivers/base/firmware_loader/sysfs.c
new file mode 100644
index 000000000..5b66b3d1f
--- /dev/null
+++ b/drivers/base/firmware_loader/sysfs.c
@@ -0,0 +1,419 @@
+// 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 "sysfs.h"
+
+/*
+ * sysfs support for firmware loader
+ */
+
+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_state_is_done(fw_priv))
+ return;
+
+ fw_state_aborted(fw_priv);
+}
+
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+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 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 void fw_dev_release(struct device *dev)
+{
+ struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
+
+ if (fw_sysfs->fw_upload_priv)
+ fw_upload_free(fw_sysfs);
+
+ kfree(fw_sysfs);
+}
+
+static struct class firmware_class = {
+ .name = "firmware",
+#ifdef CONFIG_FW_LOADER_USER_HELPER
+ .class_groups = firmware_class_groups,
+ .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_state_is_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 */
+ fw_free_paged_buf(fw_priv);
+ fw_state_start(fw_priv);
+ break;
+ case 0:
+ if (fw_state_is_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);
+
+ /*
+ * If this is a user-initiated firmware upload
+ * then start the upload in a worker thread now.
+ */
+ rc = fw_upload_start(fw_sysfs);
+ if (rc)
+ written = rc;
+ }
+ break;
+ }
+ fallthrough;
+ default:
+ dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
+ fallthrough;
+ case -1:
+ fw_load_abort(fw_sysfs);
+ if (fw_sysfs->fw_upload_priv)
+ fw_state_init(fw_sysfs->fw_priv);
+
+ break;
+ }
+out:
+ mutex_unlock(&fw_lock);
+ return written;
+}
+
+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) {
+ 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);
+
+ if (read)
+ memcpy_from_page(buffer, fw_priv->pages[page_nr],
+ page_ofs, page_cnt);
+ else
+ memcpy_to_page(fw_priv->pages[page_nr], page_ofs,
+ buffer, page_cnt);
+
+ 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_state_is_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_state_is_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,
+#ifdef CONFIG_FW_UPLOAD
+ &dev_attr_cancel.attr,
+ &dev_attr_status.attr,
+ &dev_attr_error.attr,
+ &dev_attr_remaining_size.attr,
+#endif
+ 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,
+#ifdef CONFIG_FW_UPLOAD
+ .is_visible = fw_upload_is_visible,
+#endif
+};
+
+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;
+}