1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/highmem.h>
4 #include <linux/module.h>
5 #include <linux/security.h>
6 #include <linux/slab.h>
7 #include <linux/types.h>
12 * sysfs support for firmware loader
15 void __fw_load_abort(struct fw_priv *fw_priv)
18 * There is a small window in which user can write to 'loading'
19 * between loading done/aborted and disappearance of 'loading'
21 if (fw_state_is_aborted(fw_priv) || fw_state_is_done(fw_priv))
24 fw_state_aborted(fw_priv);
27 #ifdef CONFIG_FW_LOADER_USER_HELPER
28 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
31 return sysfs_emit(buf, "%d\n", __firmware_loading_timeout());
35 * timeout_store() - set number of seconds to wait for firmware
36 * @class: device class pointer
37 * @attr: device attribute pointer
38 * @buf: buffer to scan for timeout value
39 * @count: number of bytes in @buf
41 * Sets the number of seconds to wait for the firmware. Once
42 * this expires an error will be returned to the driver and no
43 * firmware will be provided.
45 * Note: zero means 'wait forever'.
47 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
48 const char *buf, size_t count)
50 int tmp_loading_timeout = simple_strtol(buf, NULL, 10);
52 if (tmp_loading_timeout < 0)
53 tmp_loading_timeout = 0;
55 __fw_fallback_set_timeout(tmp_loading_timeout);
59 static CLASS_ATTR_RW(timeout);
61 static struct attribute *firmware_class_attrs[] = {
62 &class_attr_timeout.attr,
65 ATTRIBUTE_GROUPS(firmware_class);
67 static int do_firmware_uevent(struct fw_sysfs *fw_sysfs, struct kobj_uevent_env *env)
69 if (add_uevent_var(env, "FIRMWARE=%s", fw_sysfs->fw_priv->fw_name))
71 if (add_uevent_var(env, "TIMEOUT=%i", __firmware_loading_timeout()))
73 if (add_uevent_var(env, "ASYNC=%d", fw_sysfs->nowait))
79 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
81 struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
85 if (fw_sysfs->fw_priv)
86 err = do_firmware_uevent(fw_sysfs, env);
87 mutex_unlock(&fw_lock);
90 #endif /* CONFIG_FW_LOADER_USER_HELPER */
92 static void fw_dev_release(struct device *dev)
94 struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
96 if (fw_sysfs->fw_upload_priv) {
97 free_fw_priv(fw_sysfs->fw_priv);
98 kfree(fw_sysfs->fw_upload_priv);
103 static struct class firmware_class = {
105 #ifdef CONFIG_FW_LOADER_USER_HELPER
106 .class_groups = firmware_class_groups,
107 .dev_uevent = firmware_uevent,
109 .dev_release = fw_dev_release,
112 int register_sysfs_loader(void)
114 int ret = class_register(&firmware_class);
118 return register_firmware_config_sysctl();
121 void unregister_sysfs_loader(void)
123 unregister_firmware_config_sysctl();
124 class_unregister(&firmware_class);
127 static ssize_t firmware_loading_show(struct device *dev,
128 struct device_attribute *attr, char *buf)
130 struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
133 mutex_lock(&fw_lock);
134 if (fw_sysfs->fw_priv)
135 loading = fw_state_is_loading(fw_sysfs->fw_priv);
136 mutex_unlock(&fw_lock);
138 return sysfs_emit(buf, "%d\n", loading);
142 * firmware_loading_store() - set value in the 'loading' control file
143 * @dev: device pointer
144 * @attr: device attribute pointer
145 * @buf: buffer to scan for loading control value
146 * @count: number of bytes in @buf
148 * The relevant values are:
150 * 1: Start a load, discarding any previous partial load.
151 * 0: Conclude the load and hand the data to the driver code.
152 * -1: Conclude the load with an error and discard any written data.
154 static ssize_t firmware_loading_store(struct device *dev,
155 struct device_attribute *attr,
156 const char *buf, size_t count)
158 struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
159 struct fw_priv *fw_priv;
160 ssize_t written = count;
161 int loading = simple_strtol(buf, NULL, 10);
163 mutex_lock(&fw_lock);
164 fw_priv = fw_sysfs->fw_priv;
165 if (fw_state_is_aborted(fw_priv) || fw_state_is_done(fw_priv))
170 /* discarding any previous partial load */
171 fw_free_paged_buf(fw_priv);
172 fw_state_start(fw_priv);
175 if (fw_state_is_loading(fw_priv)) {
179 * Several loading requests may be pending on
180 * one same firmware buf, so let all requests
181 * see the mapped 'buf->data' once the loading
184 rc = fw_map_paged_buf(fw_priv);
186 dev_err(dev, "%s: map pages failed\n",
189 rc = security_kernel_post_load_data(fw_priv->data,
195 * Same logic as fw_load_abort, only the DONE bit
196 * is ignored and we set ABORT only on failure.
199 fw_state_aborted(fw_priv);
202 fw_state_done(fw_priv);
205 * If this is a user-initiated firmware upload
206 * then start the upload in a worker thread now.
208 rc = fw_upload_start(fw_sysfs);
216 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
219 fw_load_abort(fw_sysfs);
220 if (fw_sysfs->fw_upload_priv)
221 fw_state_init(fw_sysfs->fw_priv);
226 mutex_unlock(&fw_lock);
230 DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
232 static void firmware_rw_data(struct fw_priv *fw_priv, char *buffer,
233 loff_t offset, size_t count, bool read)
236 memcpy(buffer, fw_priv->data + offset, count);
238 memcpy(fw_priv->data + offset, buffer, count);
241 static void firmware_rw(struct fw_priv *fw_priv, char *buffer,
242 loff_t offset, size_t count, bool read)
246 int page_nr = offset >> PAGE_SHIFT;
247 int page_ofs = offset & (PAGE_SIZE - 1);
248 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
250 page_data = kmap(fw_priv->pages[page_nr]);
253 memcpy(buffer, page_data + page_ofs, page_cnt);
255 memcpy(page_data + page_ofs, buffer, page_cnt);
257 kunmap(fw_priv->pages[page_nr]);
264 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
265 struct bin_attribute *bin_attr,
266 char *buffer, loff_t offset, size_t count)
268 struct device *dev = kobj_to_dev(kobj);
269 struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
270 struct fw_priv *fw_priv;
273 mutex_lock(&fw_lock);
274 fw_priv = fw_sysfs->fw_priv;
275 if (!fw_priv || fw_state_is_done(fw_priv)) {
279 if (offset > fw_priv->size) {
283 if (count > fw_priv->size - offset)
284 count = fw_priv->size - offset;
289 firmware_rw_data(fw_priv, buffer, offset, count, true);
291 firmware_rw(fw_priv, buffer, offset, count, true);
294 mutex_unlock(&fw_lock);
298 static int fw_realloc_pages(struct fw_sysfs *fw_sysfs, int min_size)
302 err = fw_grow_paged_buf(fw_sysfs->fw_priv,
303 PAGE_ALIGN(min_size) >> PAGE_SHIFT);
305 fw_load_abort(fw_sysfs);
310 * firmware_data_write() - write method for firmware
311 * @filp: open sysfs file
312 * @kobj: kobject for the device
313 * @bin_attr: bin_attr structure
314 * @buffer: buffer being written
315 * @offset: buffer offset for write in total data store area
316 * @count: buffer size
318 * Data written to the 'data' attribute will be later handed to
319 * the driver as a firmware image.
321 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
322 struct bin_attribute *bin_attr,
323 char *buffer, loff_t offset, size_t count)
325 struct device *dev = kobj_to_dev(kobj);
326 struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
327 struct fw_priv *fw_priv;
330 if (!capable(CAP_SYS_RAWIO))
333 mutex_lock(&fw_lock);
334 fw_priv = fw_sysfs->fw_priv;
335 if (!fw_priv || fw_state_is_done(fw_priv)) {
341 if (offset + count > fw_priv->allocated_size) {
345 firmware_rw_data(fw_priv, buffer, offset, count, false);
348 retval = fw_realloc_pages(fw_sysfs, offset + count);
353 firmware_rw(fw_priv, buffer, offset, count, false);
356 fw_priv->size = max_t(size_t, offset + count, fw_priv->size);
358 mutex_unlock(&fw_lock);
362 static struct bin_attribute firmware_attr_data = {
363 .attr = { .name = "data", .mode = 0644 },
365 .read = firmware_data_read,
366 .write = firmware_data_write,
369 static struct attribute *fw_dev_attrs[] = {
370 &dev_attr_loading.attr,
371 #ifdef CONFIG_FW_UPLOAD
372 &dev_attr_cancel.attr,
373 &dev_attr_status.attr,
374 &dev_attr_error.attr,
375 &dev_attr_remaining_size.attr,
380 static struct bin_attribute *fw_dev_bin_attrs[] = {
385 static const struct attribute_group fw_dev_attr_group = {
386 .attrs = fw_dev_attrs,
387 .bin_attrs = fw_dev_bin_attrs,
388 #ifdef CONFIG_FW_UPLOAD
389 .is_visible = fw_upload_is_visible,
393 static const struct attribute_group *fw_dev_attr_groups[] = {
399 fw_create_instance(struct firmware *firmware, const char *fw_name,
400 struct device *device, u32 opt_flags)
402 struct fw_sysfs *fw_sysfs;
403 struct device *f_dev;
405 fw_sysfs = kzalloc(sizeof(*fw_sysfs), GFP_KERNEL);
407 fw_sysfs = ERR_PTR(-ENOMEM);
411 fw_sysfs->nowait = !!(opt_flags & FW_OPT_NOWAIT);
412 fw_sysfs->fw = firmware;
413 f_dev = &fw_sysfs->dev;
415 device_initialize(f_dev);
416 dev_set_name(f_dev, "%s", fw_name);
417 f_dev->parent = device;
418 f_dev->class = &firmware_class;
419 f_dev->groups = fw_dev_attr_groups;