#include <linux/device.h>
#include <linux/export.h>
#include <linux/file.h>
#include <linux/posix-clock.h>
#include <linux/slab.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include "posix-timers.h"
static struct posix_clock *get_posix_clock(struct file *fp)
{
struct posix_clock_context *pccontext = fp->private_data;
struct posix_clock *clk = pccontext->clk;
down_read(&clk->rwsem);
if (!clk->zombie)
return clk;
up_read(&clk->rwsem);
return NULL;
}
static void put_posix_clock(struct posix_clock *clk)
{
up_read(&clk->rwsem);
}
static ssize_t posix_clock_read(struct file *fp, char __user *buf,
size_t count, loff_t *ppos)
{
struct posix_clock_context *pccontext = fp->private_data;
struct posix_clock *clk = get_posix_clock(fp);
int err = -EINVAL;
if (!clk)
return -ENODEV;
if (clk->ops.read)
err = clk->ops.read(pccontext, fp->f_flags, buf, count);
put_posix_clock(clk);
return err;
}
static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
{
struct posix_clock_context *pccontext = fp->private_data;
struct posix_clock *clk = get_posix_clock(fp);
__poll_t result = 0;
if (!clk)
return EPOLLERR;
if (clk->ops.poll)
result = clk->ops.poll(pccontext, fp, wait);
put_posix_clock(clk);
return result;
}
static long posix_clock_ioctl(struct file *fp,
unsigned int cmd, unsigned long arg)
{
struct posix_clock_context *pccontext = fp->private_data;
struct posix_clock *clk = get_posix_clock(fp);
int err = -ENOTTY;
if (!clk)
return -ENODEV;
if (clk->ops.ioctl)
err = clk->ops.ioctl(pccontext, cmd, arg);
put_posix_clock(clk);
return err;
}
static int posix_clock_open(struct inode *inode, struct file *fp)
{
int err;
struct posix_clock *clk =
container_of(inode->i_cdev, struct posix_clock, cdev);
struct posix_clock_context *pccontext;
down_read(&clk->rwsem);
if (clk->zombie) {
err = -ENODEV;
goto out;
}
pccontext = kzalloc_obj(*pccontext);
if (!pccontext) {
err = -ENOMEM;
goto out;
}
pccontext->clk = clk;
pccontext->fp = fp;
if (clk->ops.open) {
err = clk->ops.open(pccontext, fp->f_mode);
if (err) {
kfree(pccontext);
goto out;
}
}
fp->private_data = pccontext;
get_device(clk->dev);
err = 0;
out:
up_read(&clk->rwsem);
return err;
}
static int posix_clock_release(struct inode *inode, struct file *fp)
{
struct posix_clock_context *pccontext = fp->private_data;
struct posix_clock *clk;
int err = 0;
if (!pccontext)
return -ENODEV;
clk = pccontext->clk;
if (clk->ops.release)
err = clk->ops.release(pccontext);
put_device(clk->dev);
kfree(pccontext);
fp->private_data = NULL;
return err;
}
static const struct file_operations posix_clock_file_operations = {
.owner = THIS_MODULE,
.read = posix_clock_read,
.poll = posix_clock_poll,
.unlocked_ioctl = posix_clock_ioctl,
.compat_ioctl = posix_clock_ioctl,
.open = posix_clock_open,
.release = posix_clock_release,
};
int posix_clock_register(struct posix_clock *clk, struct device *dev)
{
int err;
init_rwsem(&clk->rwsem);
cdev_init(&clk->cdev, &posix_clock_file_operations);
err = cdev_device_add(&clk->cdev, dev);
if (err) {
pr_err("%s unable to add device %d:%d\n",
dev_name(dev), MAJOR(dev->devt), MINOR(dev->devt));
return err;
}
clk->cdev.owner = clk->ops.owner;
clk->dev = dev;
return 0;
}
EXPORT_SYMBOL_GPL(posix_clock_register);
void posix_clock_unregister(struct posix_clock *clk)
{
cdev_device_del(&clk->cdev, clk->dev);
down_write(&clk->rwsem);
clk->zombie = true;
up_write(&clk->rwsem);
put_device(clk->dev);
}
EXPORT_SYMBOL_GPL(posix_clock_unregister);
struct posix_clock_desc {
struct file *fp;
struct posix_clock *clk;
};
static int get_clock_desc(const clockid_t id, struct posix_clock_desc *cd)
{
struct file *fp = fget(clockid_to_fd(id));
int err = -EINVAL;
if (!fp)
return err;
if (fp->f_op->open != posix_clock_open || !fp->private_data)
goto out;
cd->fp = fp;
cd->clk = get_posix_clock(fp);
err = cd->clk ? 0 : -ENODEV;
out:
if (err)
fput(fp);
return err;
}
static void put_clock_desc(struct posix_clock_desc *cd)
{
put_posix_clock(cd->clk);
fput(cd->fp);
}
static int pc_clock_adjtime(clockid_t id, struct __kernel_timex *tx)
{
struct posix_clock_desc cd;
int err;
err = get_clock_desc(id, &cd);
if (err)
return err;
if (tx->modes && (cd.fp->f_mode & FMODE_WRITE) == 0) {
err = -EACCES;
goto out;
}
if (cd.clk->ops.clock_adjtime)
err = cd.clk->ops.clock_adjtime(cd.clk, tx);
else
err = -EOPNOTSUPP;
out:
put_clock_desc(&cd);
return err;
}
static int pc_clock_gettime(clockid_t id, struct timespec64 *ts)
{
struct posix_clock_desc cd;
int err;
err = get_clock_desc(id, &cd);
if (err)
return err;
if (cd.clk->ops.clock_gettime)
err = cd.clk->ops.clock_gettime(cd.clk, ts);
else
err = -EOPNOTSUPP;
put_clock_desc(&cd);
return err;
}
static int pc_clock_getres(clockid_t id, struct timespec64 *ts)
{
struct posix_clock_desc cd;
int err;
err = get_clock_desc(id, &cd);
if (err)
return err;
if (cd.clk->ops.clock_getres)
err = cd.clk->ops.clock_getres(cd.clk, ts);
else
err = -EOPNOTSUPP;
put_clock_desc(&cd);
return err;
}
static int pc_clock_settime(clockid_t id, const struct timespec64 *ts)
{
struct posix_clock_desc cd;
int err;
if (!timespec64_valid_strict(ts))
return -EINVAL;
err = get_clock_desc(id, &cd);
if (err)
return err;
if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
err = -EACCES;
goto out;
}
if (cd.clk->ops.clock_settime)
err = cd.clk->ops.clock_settime(cd.clk, ts);
else
err = -EOPNOTSUPP;
out:
put_clock_desc(&cd);
return err;
}
const struct k_clock clock_posix_dynamic = {
.clock_getres = pc_clock_getres,
.clock_set = pc_clock_settime,
.clock_get_timespec = pc_clock_gettime,
.clock_adj = pc_clock_adjtime,
};
