linux-stable/kernel/time/posix-clock.c
Paul Gortmaker 6e5fdeedca kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure
These files were getting <linux/module.h> via an implicit non-obvious
path, but we want to crush those out of existence since they cost
time during compiles of processing thousands of lines of headers
for no reason.  Give them the lightweight header that just contains
the EXPORT_SYMBOL infrastructure.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:05 -04:00

446 lines
8.4 KiB
C

/*
* posix-clock.c - support for dynamic clock devices
*
* Copyright (C) 2010 OMICRON electronics GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#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>
static void delete_clock(struct kref *kref);
/*
* Returns NULL if the posix_clock instance attached to 'fp' is old and stale.
*/
static struct posix_clock *get_posix_clock(struct file *fp)
{
struct posix_clock *clk = fp->private_data;
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 *clk = get_posix_clock(fp);
int err = -EINVAL;
if (!clk)
return -ENODEV;
if (clk->ops.read)
err = clk->ops.read(clk, fp->f_flags, buf, count);
put_posix_clock(clk);
return err;
}
static unsigned int posix_clock_poll(struct file *fp, poll_table *wait)
{
struct posix_clock *clk = get_posix_clock(fp);
int result = 0;
if (!clk)
return -ENODEV;
if (clk->ops.poll)
result = clk->ops.poll(clk, fp, wait);
put_posix_clock(clk);
return result;
}
static int posix_clock_fasync(int fd, struct file *fp, int on)
{
struct posix_clock *clk = get_posix_clock(fp);
int err = 0;
if (!clk)
return -ENODEV;
if (clk->ops.fasync)
err = clk->ops.fasync(clk, fd, fp, on);
put_posix_clock(clk);
return err;
}
static int posix_clock_mmap(struct file *fp, struct vm_area_struct *vma)
{
struct posix_clock *clk = get_posix_clock(fp);
int err = -ENODEV;
if (!clk)
return -ENODEV;
if (clk->ops.mmap)
err = clk->ops.mmap(clk, vma);
put_posix_clock(clk);
return err;
}
static long posix_clock_ioctl(struct file *fp,
unsigned int cmd, unsigned long arg)
{
struct posix_clock *clk = get_posix_clock(fp);
int err = -ENOTTY;
if (!clk)
return -ENODEV;
if (clk->ops.ioctl)
err = clk->ops.ioctl(clk, cmd, arg);
put_posix_clock(clk);
return err;
}
#ifdef CONFIG_COMPAT
static long posix_clock_compat_ioctl(struct file *fp,
unsigned int cmd, unsigned long arg)
{
struct posix_clock *clk = get_posix_clock(fp);
int err = -ENOTTY;
if (!clk)
return -ENODEV;
if (clk->ops.ioctl)
err = clk->ops.ioctl(clk, cmd, arg);
put_posix_clock(clk);
return err;
}
#endif
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);
down_read(&clk->rwsem);
if (clk->zombie) {
err = -ENODEV;
goto out;
}
if (clk->ops.open)
err = clk->ops.open(clk, fp->f_mode);
else
err = 0;
if (!err) {
kref_get(&clk->kref);
fp->private_data = clk;
}
out:
up_read(&clk->rwsem);
return err;
}
static int posix_clock_release(struct inode *inode, struct file *fp)
{
struct posix_clock *clk = fp->private_data;
int err = 0;
if (clk->ops.release)
err = clk->ops.release(clk);
kref_put(&clk->kref, delete_clock);
fp->private_data = NULL;
return err;
}
static const struct file_operations posix_clock_file_operations = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = posix_clock_read,
.poll = posix_clock_poll,
.unlocked_ioctl = posix_clock_ioctl,
.open = posix_clock_open,
.release = posix_clock_release,
.fasync = posix_clock_fasync,
.mmap = posix_clock_mmap,
#ifdef CONFIG_COMPAT
.compat_ioctl = posix_clock_compat_ioctl,
#endif
};
int posix_clock_register(struct posix_clock *clk, dev_t devid)
{
int err;
kref_init(&clk->kref);
init_rwsem(&clk->rwsem);
cdev_init(&clk->cdev, &posix_clock_file_operations);
clk->cdev.owner = clk->ops.owner;
err = cdev_add(&clk->cdev, devid, 1);
return err;
}
EXPORT_SYMBOL_GPL(posix_clock_register);
static void delete_clock(struct kref *kref)
{
struct posix_clock *clk = container_of(kref, struct posix_clock, kref);
if (clk->release)
clk->release(clk);
}
void posix_clock_unregister(struct posix_clock *clk)
{
cdev_del(&clk->cdev);
down_write(&clk->rwsem);
clk->zombie = true;
up_write(&clk->rwsem);
kref_put(&clk->kref, delete_clock);
}
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 timex *tx)
{
struct posix_clock_desc cd;
int err;
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_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 timespec *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 timespec *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 timespec *ts)
{
struct posix_clock_desc cd;
int err;
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;
}
static int pc_timer_create(struct k_itimer *kit)
{
clockid_t id = kit->it_clock;
struct posix_clock_desc cd;
int err;
err = get_clock_desc(id, &cd);
if (err)
return err;
if (cd.clk->ops.timer_create)
err = cd.clk->ops.timer_create(cd.clk, kit);
else
err = -EOPNOTSUPP;
put_clock_desc(&cd);
return err;
}
static int pc_timer_delete(struct k_itimer *kit)
{
clockid_t id = kit->it_clock;
struct posix_clock_desc cd;
int err;
err = get_clock_desc(id, &cd);
if (err)
return err;
if (cd.clk->ops.timer_delete)
err = cd.clk->ops.timer_delete(cd.clk, kit);
else
err = -EOPNOTSUPP;
put_clock_desc(&cd);
return err;
}
static void pc_timer_gettime(struct k_itimer *kit, struct itimerspec *ts)
{
clockid_t id = kit->it_clock;
struct posix_clock_desc cd;
if (get_clock_desc(id, &cd))
return;
if (cd.clk->ops.timer_gettime)
cd.clk->ops.timer_gettime(cd.clk, kit, ts);
put_clock_desc(&cd);
}
static int pc_timer_settime(struct k_itimer *kit, int flags,
struct itimerspec *ts, struct itimerspec *old)
{
clockid_t id = kit->it_clock;
struct posix_clock_desc cd;
int err;
err = get_clock_desc(id, &cd);
if (err)
return err;
if (cd.clk->ops.timer_settime)
err = cd.clk->ops.timer_settime(cd.clk, kit, flags, ts, old);
else
err = -EOPNOTSUPP;
put_clock_desc(&cd);
return err;
}
struct k_clock clock_posix_dynamic = {
.clock_getres = pc_clock_getres,
.clock_set = pc_clock_settime,
.clock_get = pc_clock_gettime,
.clock_adj = pc_clock_adjtime,
.timer_create = pc_timer_create,
.timer_set = pc_timer_settime,
.timer_del = pc_timer_delete,
.timer_get = pc_timer_gettime,
};