diff options
| -rw-r--r-- | Documentation/input/userio.txt | 70 | ||||
| -rw-r--r-- | MAINTAINERS | 6 | ||||
| -rw-r--r-- | drivers/input/serio/Kconfig | 14 | ||||
| -rw-r--r-- | drivers/input/serio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/input/serio/userio.c | 285 | ||||
| -rw-r--r-- | include/linux/miscdevice.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/userio.h | 44 |
7 files changed, 421 insertions, 0 deletions
diff --git a/Documentation/input/userio.txt b/Documentation/input/userio.txt new file mode 100644 index 000000000000..0880c0f447a6 --- /dev/null +++ b/Documentation/input/userio.txt @@ -0,0 +1,70 @@ + The userio Protocol + (c) 2015 Stephen Chandler Paul <thatslyude@gmail.com> + Sponsored by Red Hat +-------------------------------------------------------------------------------- + +1. Introduction +~~~~~~~~~~~~~~~ + This module is intended to try to make the lives of input driver developers +easier by allowing them to test various serio devices (mainly the various +touchpads found on laptops) without having to have the physical device in front +of them. userio accomplishes this by allowing any privileged userspace program +to directly interact with the kernel's serio driver and control a virtual serio +port from there. + +2. Usage overview +~~~~~~~~~~~~~~~~~ + In order to interact with the userio kernel module, one simply opens the +/dev/userio character device in their applications. Commands are sent to the +kernel module by writing to the device, and any data received from the serio +driver is read as-is from the /dev/userio device. All of the structures and +macros you need to interact with the device are defined in <linux/userio.h> and +<linux/serio.h>. + +3. Command Structure +~~~~~~~~~~~~~~~~~~~~ + The struct used for sending commands to /dev/userio is as follows: + + struct userio_cmd { + __u8 type; + __u8 data; + }; + + "type" describes the type of command that is being sent. This can be any one +of the USERIO_CMD macros defined in <linux/userio.h>. "data" is the argument +that goes along with the command. In the event that the command doesn't have an +argument, this field can be left untouched and will be ignored by the kernel. +Each command should be sent by writing the struct directly to the character +device. In the event that the command you send is invalid, an error will be +returned by the character device and a more descriptive error will be printed +to the kernel log. Only one command can be sent at a time, any additional data +written to the character device after the initial command will be ignored. + To close the virtual serio port, just close /dev/userio. + +4. Commands +~~~~~~~~~~~ + +4.1 USERIO_CMD_REGISTER +~~~~~~~~~~~~~~~~~~~~~~~ + Registers the port with the serio driver and begins transmitting data back and +forth. Registration can only be performed once a port type is set with +USERIO_CMD_SET_PORT_TYPE. Has no argument. + +4.2 USERIO_CMD_SET_PORT_TYPE +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + Sets the type of port we're emulating, where "data" is the port type being +set. Can be any of the macros from <linux/serio.h>. For example: SERIO_8042 +would set the port type to be a normal PS/2 port. + +4.3 USERIO_CMD_SEND_INTERRUPT +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + Sends an interrupt through the virtual serio port to the serio driver, where +"data" is the interrupt data being sent. + +5. Userspace tools +~~~~~~~~~~~~~~~~~~ + The userio userspace tools are able to record PS/2 devices using some of the +debugging information from i8042, and play back the devices on /dev/userio. The +latest version of these tools can be found at: + + https://github.com/Lyude/ps2emu diff --git a/MAINTAINERS b/MAINTAINERS index 797236befd27..ba59bd7b3557 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11100,6 +11100,12 @@ S: Maintained F: drivers/media/v4l2-core/videobuf2-* F: include/media/videobuf2-* +VIRTUAL SERIO DEVICE DRIVER +M: Stephen Chandler Paul <thatslyude@gmail.com> +S: Maintained +F: drivers/input/serio/userio.c +F: include/uapi/linux/userio.h + VIRTIO CONSOLE DRIVER M: Amit Shah <amit.shah@redhat.com> L: virtualization@lists.linux-foundation.org diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig index 200841b77edb..c3d05b4d3118 100644 --- a/drivers/input/serio/Kconfig +++ b/drivers/input/serio/Kconfig @@ -292,4 +292,18 @@ config SERIO_SUN4I_PS2 To compile this driver as a module, choose M here: the module will be called sun4i-ps2. +config USERIO + tristate "User space serio port driver support" + help + Say Y here if you want to support user level drivers for serio + subsystem accessible under char device 10:240 - /dev/userio. Using + this facility userspace programs can implement serio ports that + will be used by the standard in-kernel serio consumer drivers, + such as psmouse and atkbd. + + To compile this driver as a module, choose M here: the module will be + called userio. + + If you are unsure, say N. + endif diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile index c600089b7a34..2374ef9b33d7 100644 --- a/drivers/input/serio/Makefile +++ b/drivers/input/serio/Makefile @@ -30,3 +30,4 @@ obj-$(CONFIG_SERIO_APBPS2) += apbps2.o obj-$(CONFIG_SERIO_OLPC_APSP) += olpc_apsp.o obj-$(CONFIG_HYPERV_KEYBOARD) += hyperv-keyboard.o obj-$(CONFIG_SERIO_SUN4I_PS2) += sun4i-ps2.o +obj-$(CONFIG_USERIO) += userio.o diff --git a/drivers/input/serio/userio.c b/drivers/input/serio/userio.c new file mode 100644 index 000000000000..df1fd41860ac --- /dev/null +++ b/drivers/input/serio/userio.c @@ -0,0 +1,285 @@ +/* + * userio kernel serio device emulation module + * Copyright (C) 2015 Red Hat + * Copyright (C) 2015 Stephen Chandler Paul <thatslyude@gmail.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser + * General Public License for more details. + */ + +#include <linux/circ_buf.h> +#include <linux/mutex.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/serio.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/sched.h> +#include <linux/poll.h> +#include <uapi/linux/userio.h> + +#define USERIO_NAME "userio" +#define USERIO_BUFSIZE 16 + +static struct miscdevice userio_misc; + +struct userio_device { + struct serio *serio; + struct mutex mutex; + + bool running; + + u8 head; + u8 tail; + + spinlock_t buf_lock; + unsigned char buf[USERIO_BUFSIZE]; + + wait_queue_head_t waitq; +}; + +/** + * userio_device_write - Write data from serio to a userio device in userspace + * @id: The serio port for the userio device + * @val: The data to write to the device + */ +static int userio_device_write(struct serio *id, unsigned char val) +{ + struct userio_device *userio = id->port_data; + unsigned long flags; + + spin_lock_irqsave(&userio->buf_lock, flags); + + userio->buf[userio->head] = val; + userio->head = (userio->head + 1) % USERIO_BUFSIZE; + + if (userio->head == userio->tail) + dev_warn(userio_misc.this_device, + "Buffer overflowed, userio client isn't keeping up"); + + spin_unlock_irqrestore(&userio->buf_lock, flags); + + wake_up_interruptible(&userio->waitq); + + return 0; +} + +static int userio_char_open(struct inode *inode, struct file *file) +{ + struct userio_device *userio; + + userio = kzalloc(sizeof(struct userio_device), GFP_KERNEL); + if (!userio) + return -ENOMEM; + + mutex_init(&userio->mutex); + spin_lock_init(&userio->buf_lock); + init_waitqueue_head(&userio->waitq); + + userio->serio = kzalloc(sizeof(struct serio), GFP_KERNEL); + if (!userio->serio) { + kfree(userio); + return -ENOMEM; + } + + userio->serio->write = userio_device_write; + userio->serio->port_data = userio; + + file->private_data = userio; + + return 0; +} + +static int userio_char_release(struct inode *inode, struct file *file) +{ + struct userio_device *userio = file->private_data; + + if (userio->running) { + /* + * Don't free the serio port here, serio_unregister_port() + * does it for us. + */ + serio_unregister_port(userio->serio); + } else { + kfree(userio->serio); + } + + kfree(userio); + + return 0; +} + +static ssize_t userio_char_read(struct file *file, char __user *user_buffer, + size_t count, loff_t *ppos) +{ + struct userio_device *userio = file->private_data; + int error; + size_t nonwrap_len, copylen; + unsigned char buf[USERIO_BUFSIZE]; + unsigned long flags; + + /* + * By the time we get here, the data that was waiting might have + * been taken by another thread. Grab the buffer lock and check if + * there's still any data waiting, otherwise repeat this process + * until we have data (unless the file descriptor is non-blocking + * of course). + */ + for (;;) { + spin_lock_irqsave(&userio->buf_lock, flags); + + nonwrap_len = CIRC_CNT_TO_END(userio->head, + userio->tail, + USERIO_BUFSIZE); + copylen = min(nonwrap_len, count); + if (copylen) { + memcpy(buf, &userio->buf[userio->tail], copylen); + userio->tail = (userio->tail + copylen) % + USERIO_BUFSIZE; + } + + spin_unlock_irqrestore(&userio->buf_lock, flags); + + if (nonwrap_len) + break; + + /* buffer was/is empty */ + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + /* + * count == 0 is special - no IO is done but we check + * for error conditions (see above). + */ + if (count == 0) + return 0; + + error = wait_event_interruptible(userio->waitq, + userio->head != userio->tail); + if (error) + return error; + } + + if (copylen) + if (copy_to_user(user_buffer, buf, copylen)) + return -EFAULT; + + return copylen; +} + +static ssize_t userio_char_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + struct userio_device *userio = file->private_data; + struct userio_cmd cmd; + int error; + + if (count != sizeof(cmd)) { + dev_warn(userio_misc.this_device, "Invalid payload size\n"); + return -EINVAL; + } + + if (copy_from_user(&cmd, buffer, sizeof(cmd))) + return -EFAULT; + + error = mutex_lock_interruptible(&userio->mutex); + if (error) + return error; + + switch (cmd.type) { + case USERIO_CMD_REGISTER: + if (!userio->serio->id.type) { + dev_warn(userio_misc.this_device, + "No port type given on /dev/userio\n"); + + error = -EINVAL; + goto out; + } + + if (userio->running) { + dev_warn(userio_misc.this_device, + "Begin command sent, but we're already running\n"); + error = -EBUSY; + goto out; + } + + userio->running = true; + serio_register_port(userio->serio); + break; + + case USERIO_CMD_SET_PORT_TYPE: + if (userio->running) { + dev_warn(userio_misc.this_device, + "Can't change port type on an already running userio instance\n"); + error = -EBUSY; + goto out; + } + + userio->serio->id.type = cmd.data; + break; + + case USERIO_CMD_SEND_INTERRUPT: + if (!userio->running) { + dev_warn(userio_misc.this_device, + "The device must be registered before sending interrupts\n"); + error = -ENODEV; + goto out; + } + + serio_interrupt(userio->serio, cmd.data, 0); + break; + + default: + error = -EOPNOTSUPP; + goto out; + } + +out: + mutex_unlock(&userio->mutex); + return error ?: count; +} + +static unsigned int userio_char_poll(struct file *file, poll_table *wait) +{ + struct userio_device *userio = file->private_data; + + poll_wait(file, &userio->waitq, wait); + + if (userio->head != userio->tail) + return POLLIN | POLLRDNORM; + + return 0; +} + +static const struct file_operations userio_fops = { + .owner = THIS_MODULE, + .open = userio_char_open, + .release = userio_char_release, + .read = userio_char_read, + .write = userio_char_write, + .poll = userio_char_poll, + .llseek = no_llseek, +}; + +static struct miscdevice userio_misc = { + .fops = &userio_fops, + .minor = USERIO_MINOR, + .name = USERIO_NAME, +}; +module_driver(userio_misc, misc_register, misc_deregister); + +MODULE_ALIAS_MISCDEV(USERIO_MINOR); +MODULE_ALIAS("devname:" USERIO_NAME); + +MODULE_AUTHOR("Stephen Chandler Paul <thatslyude@gmail.com>"); +MODULE_DESCRIPTION("Virtual Serio Device Support"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h index 81f6e427ba6b..543037465973 100644 --- a/include/linux/miscdevice.h +++ b/include/linux/miscdevice.h @@ -49,6 +49,7 @@ #define LOOP_CTRL_MINOR 237 #define VHOST_NET_MINOR 238 #define UHID_MINOR 239 +#define USERIO_MINOR 240 #define MISC_DYNAMIC_MINOR 255 struct device; diff --git a/include/uapi/linux/userio.h b/include/uapi/linux/userio.h new file mode 100644 index 000000000000..37d147f0a13a --- /dev/null +++ b/include/uapi/linux/userio.h @@ -0,0 +1,44 @@ +/* + * userio: virtual serio device support + * Copyright (C) 2015 Red Hat + * Copyright (C) 2015 Lyude (Stephen Chandler Paul) <cpaul@redhat.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU Lesser General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more + * details. + * + * This is the public header used for user-space communication with the userio + * driver. __attribute__((__packed__)) is used for all structs to keep ABI + * compatibility between all architectures. + */ + +#ifndef _USERIO_H +#define _USERIO_H + +#include <linux/types.h> + +enum userio_cmd_type { + USERIO_CMD_REGISTER = 0, + USERIO_CMD_SET_PORT_TYPE = 1, + USERIO_CMD_SEND_INTERRUPT = 2 +}; + +/* + * userio Commands + * All commands sent to /dev/userio are encoded using this structure. The type + * field should contain a USERIO_CMD* value that indicates what kind of command + * is being sent to userio. The data field should contain the accompanying + * argument for the command, if there is one. + */ +struct userio_cmd { + __u8 type; + __u8 data; +} __attribute__((__packed__)); + +#endif /* !_USERIO_H */ |