From e09b41010ba33a20a87472ee821fa407a5b8da36 Mon Sep 17 00:00:00 2001 From: José Pekkarinen Date: Mon, 11 Apr 2016 10:41:07 +0300 Subject: These changes are the raw update to linux-4.4.6-rt14. Kernel sources are taken from kernel.org, and rt patch from the rt wiki download page. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen --- kernel/drivers/input/serio/userio.c | 285 ++++++++++++++++++++++++++++++++++++ 1 file changed, 285 insertions(+) create mode 100644 kernel/drivers/input/serio/userio.c (limited to 'kernel/drivers/input/serio/userio.c') diff --git a/kernel/drivers/input/serio/userio.c b/kernel/drivers/input/serio/userio.c new file mode 100644 index 000000000..df1fd4186 --- /dev/null +++ b/kernel/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 + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 "); +MODULE_DESCRIPTION("Virtual Serio Device Support"); +MODULE_LICENSE("GPL"); -- cgit 1.2.3-korg