blob: 5b66b3d1fa16b8126946d67daeaf6c711e7440d9 [file] [log] [blame]
// 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;
}