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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319// SPDX-License-Identifier: GPL-2.0+/* * Support for dynamic clock devices * * Copyright (C) 2010 OMICRON electronics GmbH */#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"
/* * 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_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,};