mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-05 08:26:59 +00:00
platform/x86: wmi: Remove chardev interface
The design of the WMI chardev interface is broken: - it assumes that WMI drivers are not instantiated twice - it offers next to no abstractions, the WMI driver gets a raw byte buffer - it is only used by a single driver, something which is unlikely to change Since the only user (dell-smbios-wmi) has been migrated to his own ioctl interface, remove it. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Armin Wolf <W_Armin@gmx.de> Link: https://lore.kernel.org/r/20231210202443.646427-6-W_Armin@gmx.de Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
This commit is contained in:
Armin Wolf
Hans de Goede
parent
93885e85a7
commit
704af3a407
2 changed files with 5 additions and 183 deletions
|
|
@ -23,17 +23,14 @@
|
|||
#include <linux/init.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/list.h>
|
||||
#include <linux/miscdevice.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/platform_device.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/sysfs.h>
|
||||
#include <linux/types.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <linux/uuid.h>
|
||||
#include <linux/wmi.h>
|
||||
#include <linux/fs.h>
|
||||
#include <uapi/linux/wmi.h>
|
||||
|
||||
MODULE_AUTHOR("Carlos Corbacho");
|
||||
MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
|
||||
|
|
@ -66,12 +63,9 @@ struct wmi_block {
|
|||
struct wmi_device dev;
|
||||
struct list_head list;
|
||||
struct guid_block gblock;
|
||||
struct miscdevice char_dev;
|
||||
struct mutex char_mutex;
|
||||
struct acpi_device *acpi_device;
|
||||
wmi_notify_handler handler;
|
||||
void *handler_data;
|
||||
u64 req_buf_size;
|
||||
unsigned long flags;
|
||||
};
|
||||
|
||||
|
|
@ -256,26 +250,6 @@ static void wmi_device_put(struct wmi_device *wdev)
|
|||
* Exported WMI functions
|
||||
*/
|
||||
|
||||
/**
|
||||
* set_required_buffer_size - Sets the buffer size needed for performing IOCTL
|
||||
* @wdev: A wmi bus device from a driver
|
||||
* @length: Required buffer size
|
||||
*
|
||||
* Allocates memory needed for buffer, stores the buffer size in that memory.
|
||||
*
|
||||
* Return: 0 on success or a negative error code for failure.
|
||||
*/
|
||||
int set_required_buffer_size(struct wmi_device *wdev, u64 length)
|
||||
{
|
||||
struct wmi_block *wblock;
|
||||
|
||||
wblock = container_of(wdev, struct wmi_block, dev);
|
||||
wblock->req_buf_size = length;
|
||||
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(set_required_buffer_size);
|
||||
|
||||
/**
|
||||
* wmi_instance_count - Get number of WMI object instances
|
||||
* @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
|
||||
|
|
@ -884,111 +858,12 @@ static int wmi_dev_match(struct device *dev, struct device_driver *driver)
|
|||
|
||||
return 0;
|
||||
}
|
||||
static int wmi_char_open(struct inode *inode, struct file *filp)
|
||||
{
|
||||
/*
|
||||
* The miscdevice already stores a pointer to itself
|
||||
* inside filp->private_data
|
||||
*/
|
||||
struct wmi_block *wblock = container_of(filp->private_data, struct wmi_block, char_dev);
|
||||
|
||||
filp->private_data = wblock;
|
||||
|
||||
return nonseekable_open(inode, filp);
|
||||
}
|
||||
|
||||
static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
|
||||
size_t length, loff_t *offset)
|
||||
{
|
||||
struct wmi_block *wblock = filp->private_data;
|
||||
|
||||
return simple_read_from_buffer(buffer, length, offset,
|
||||
&wblock->req_buf_size,
|
||||
sizeof(wblock->req_buf_size));
|
||||
}
|
||||
|
||||
static long wmi_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
|
||||
{
|
||||
struct wmi_ioctl_buffer __user *input =
|
||||
(struct wmi_ioctl_buffer __user *) arg;
|
||||
struct wmi_block *wblock = filp->private_data;
|
||||
struct wmi_ioctl_buffer *buf;
|
||||
struct wmi_driver *wdriver;
|
||||
int ret;
|
||||
|
||||
if (_IOC_TYPE(cmd) != WMI_IOC)
|
||||
return -ENOTTY;
|
||||
|
||||
/* make sure we're not calling a higher instance than exists*/
|
||||
if (_IOC_NR(cmd) >= wblock->gblock.instance_count)
|
||||
return -EINVAL;
|
||||
|
||||
mutex_lock(&wblock->char_mutex);
|
||||
buf = wblock->handler_data;
|
||||
if (get_user(buf->length, &input->length)) {
|
||||
dev_dbg(&wblock->dev.dev, "Read length from user failed\n");
|
||||
ret = -EFAULT;
|
||||
goto out_ioctl;
|
||||
}
|
||||
/* if it's too small, abort */
|
||||
if (buf->length < wblock->req_buf_size) {
|
||||
dev_err(&wblock->dev.dev,
|
||||
"Buffer %lld too small, need at least %lld\n",
|
||||
buf->length, wblock->req_buf_size);
|
||||
ret = -EINVAL;
|
||||
goto out_ioctl;
|
||||
}
|
||||
/* if it's too big, warn, driver will only use what is needed */
|
||||
if (buf->length > wblock->req_buf_size)
|
||||
dev_warn(&wblock->dev.dev,
|
||||
"Buffer %lld is bigger than required %lld\n",
|
||||
buf->length, wblock->req_buf_size);
|
||||
|
||||
/* copy the structure from userspace */
|
||||
if (copy_from_user(buf, input, wblock->req_buf_size)) {
|
||||
dev_dbg(&wblock->dev.dev, "Copy %llu from user failed\n",
|
||||
wblock->req_buf_size);
|
||||
ret = -EFAULT;
|
||||
goto out_ioctl;
|
||||
}
|
||||
|
||||
/* let the driver do any filtering and do the call */
|
||||
wdriver = drv_to_wdrv(wblock->dev.dev.driver);
|
||||
if (!try_module_get(wdriver->driver.owner)) {
|
||||
ret = -EBUSY;
|
||||
goto out_ioctl;
|
||||
}
|
||||
ret = wdriver->filter_callback(&wblock->dev, cmd, buf);
|
||||
module_put(wdriver->driver.owner);
|
||||
if (ret)
|
||||
goto out_ioctl;
|
||||
|
||||
/* return the result (only up to our internal buffer size) */
|
||||
if (copy_to_user(input, buf, wblock->req_buf_size)) {
|
||||
dev_dbg(&wblock->dev.dev, "Copy %llu to user failed\n",
|
||||
wblock->req_buf_size);
|
||||
ret = -EFAULT;
|
||||
}
|
||||
|
||||
out_ioctl:
|
||||
mutex_unlock(&wblock->char_mutex);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static const struct file_operations wmi_fops = {
|
||||
.owner = THIS_MODULE,
|
||||
.read = wmi_char_read,
|
||||
.open = wmi_char_open,
|
||||
.unlocked_ioctl = wmi_ioctl,
|
||||
.compat_ioctl = compat_ptr_ioctl,
|
||||
};
|
||||
|
||||
static int wmi_dev_probe(struct device *dev)
|
||||
{
|
||||
struct wmi_block *wblock = dev_to_wblock(dev);
|
||||
struct wmi_driver *wdriver = drv_to_wdrv(dev->driver);
|
||||
int ret = 0;
|
||||
char *buf;
|
||||
|
||||
if (ACPI_FAILURE(wmi_method_enable(wblock, true)))
|
||||
dev_warn(dev, "failed to enable device -- probing anyway\n");
|
||||
|
|
@ -996,55 +871,17 @@ static int wmi_dev_probe(struct device *dev)
|
|||
if (wdriver->probe) {
|
||||
ret = wdriver->probe(dev_to_wdev(dev),
|
||||
find_guid_context(wblock, wdriver));
|
||||
if (ret != 0)
|
||||
goto probe_failure;
|
||||
}
|
||||
if (!ret) {
|
||||
if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
|
||||
dev_warn(dev, "Failed to disable device\n");
|
||||
|
||||
/* driver wants a character device made */
|
||||
if (wdriver->filter_callback) {
|
||||
/* check that required buffer size declared by driver or MOF */
|
||||
if (!wblock->req_buf_size) {
|
||||
dev_err(&wblock->dev.dev,
|
||||
"Required buffer size not set\n");
|
||||
ret = -EINVAL;
|
||||
goto probe_failure;
|
||||
}
|
||||
|
||||
wblock->handler_data = kmalloc(wblock->req_buf_size,
|
||||
GFP_KERNEL);
|
||||
if (!wblock->handler_data) {
|
||||
ret = -ENOMEM;
|
||||
goto probe_failure;
|
||||
}
|
||||
|
||||
buf = kasprintf(GFP_KERNEL, "wmi/%s", wdriver->driver.name);
|
||||
if (!buf) {
|
||||
ret = -ENOMEM;
|
||||
goto probe_string_failure;
|
||||
}
|
||||
wblock->char_dev.minor = MISC_DYNAMIC_MINOR;
|
||||
wblock->char_dev.name = buf;
|
||||
wblock->char_dev.fops = &wmi_fops;
|
||||
wblock->char_dev.mode = 0444;
|
||||
ret = misc_register(&wblock->char_dev);
|
||||
if (ret) {
|
||||
dev_warn(dev, "failed to register char dev: %d\n", ret);
|
||||
ret = -ENOMEM;
|
||||
goto probe_misc_failure;
|
||||
return ret;
|
||||
}
|
||||
}
|
||||
|
||||
set_bit(WMI_PROBED, &wblock->flags);
|
||||
return 0;
|
||||
|
||||
probe_misc_failure:
|
||||
kfree(buf);
|
||||
probe_string_failure:
|
||||
kfree(wblock->handler_data);
|
||||
probe_failure:
|
||||
if (ACPI_FAILURE(wmi_method_enable(wblock, false)))
|
||||
dev_warn(dev, "failed to disable device\n");
|
||||
return ret;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void wmi_dev_remove(struct device *dev)
|
||||
|
|
@ -1054,12 +891,6 @@ static void wmi_dev_remove(struct device *dev)
|
|||
|
||||
clear_bit(WMI_PROBED, &wblock->flags);
|
||||
|
||||
if (wdriver->filter_callback) {
|
||||
misc_deregister(&wblock->char_dev);
|
||||
kfree(wblock->char_dev.name);
|
||||
kfree(wblock->handler_data);
|
||||
}
|
||||
|
||||
if (wdriver->remove)
|
||||
wdriver->remove(dev_to_wdev(dev));
|
||||
|
||||
|
|
@ -1131,7 +962,6 @@ static int wmi_create_device(struct device *wmi_bus_dev,
|
|||
|
||||
if (wblock->gblock.flags & ACPI_WMI_METHOD) {
|
||||
wblock->dev.dev.type = &wmi_type_method;
|
||||
mutex_init(&wblock->char_mutex);
|
||||
goto out_init;
|
||||
}
|
||||
|
||||
|
|
|
|||
|
|
@ -11,7 +11,6 @@
|
|||
#include <linux/device.h>
|
||||
#include <linux/acpi.h>
|
||||
#include <linux/mod_devicetable.h>
|
||||
#include <uapi/linux/wmi.h>
|
||||
|
||||
/**
|
||||
* struct wmi_device - WMI device structure
|
||||
|
|
@ -47,8 +46,6 @@ acpi_status wmidev_block_set(struct wmi_device *wdev, u8 instance, const struct
|
|||
|
||||
u8 wmidev_instance_count(struct wmi_device *wdev);
|
||||
|
||||
extern int set_required_buffer_size(struct wmi_device *wdev, u64 length);
|
||||
|
||||
/**
|
||||
* struct wmi_driver - WMI driver structure
|
||||
* @driver: Driver model structure
|
||||
|
|
@ -57,11 +54,8 @@ extern int set_required_buffer_size(struct wmi_device *wdev, u64 length);
|
|||
* @probe: Callback for device binding
|
||||
* @remove: Callback for device unbinding
|
||||
* @notify: Callback for receiving WMI events
|
||||
* @filter_callback: Callback for filtering device IOCTLs
|
||||
*
|
||||
* This represents WMI drivers which handle WMI devices.
|
||||
* @filter_callback is only necessary for drivers which
|
||||
* want to set up a WMI IOCTL interface.
|
||||
*/
|
||||
struct wmi_driver {
|
||||
struct device_driver driver;
|
||||
|
|
@ -71,8 +65,6 @@ struct wmi_driver {
|
|||
int (*probe)(struct wmi_device *wdev, const void *context);
|
||||
void (*remove)(struct wmi_device *wdev);
|
||||
void (*notify)(struct wmi_device *device, union acpi_object *data);
|
||||
long (*filter_callback)(struct wmi_device *wdev, unsigned int cmd,
|
||||
struct wmi_ioctl_buffer *arg);
|
||||
};
|
||||
|
||||
extern int __must_check __wmi_driver_register(struct wmi_driver *driver,
|
||||
|
|
|
|||
Loading…
Reference in a new issue