linux/arch/mips/kernel/rtlx.c
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00

410 lines
8.7 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
* Copyright (C) 2005, 06 Ralf Baechle (ralf@linux-mips.org)
* Copyright (C) 2013 Imagination Technologies Ltd.
*/
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/syscalls.h>
#include <linux/moduleloader.h>
#include <linux/atomic.h>
#include <linux/sched/signal.h>
#include <asm/mipsmtregs.h>
#include <asm/mips_mt.h>
#include <asm/processor.h>
#include <asm/rtlx.h>
#include <asm/setup.h>
#include <asm/vpe.h>
static int sp_stopping;
struct rtlx_info *rtlx;
struct chan_waitqueues channel_wqs[RTLX_CHANNELS];
struct vpe_notifications rtlx_notify;
void (*aprp_hook)(void) = NULL;
EXPORT_SYMBOL(aprp_hook);
static void __used dump_rtlx(void)
{
int i;
pr_info("id 0x%lx state %d\n", rtlx->id, rtlx->state);
for (i = 0; i < RTLX_CHANNELS; i++) {
struct rtlx_channel *chan = &rtlx->channel[i];
pr_info(" rt_state %d lx_state %d buffer_size %d\n",
chan->rt_state, chan->lx_state, chan->buffer_size);
pr_info(" rt_read %d rt_write %d\n",
chan->rt_read, chan->rt_write);
pr_info(" lx_read %d lx_write %d\n",
chan->lx_read, chan->lx_write);
pr_info(" rt_buffer <%s>\n", chan->rt_buffer);
pr_info(" lx_buffer <%s>\n", chan->lx_buffer);
}
}
/* call when we have the address of the shared structure from the SP side. */
static int rtlx_init(struct rtlx_info *rtlxi)
{
if (rtlxi->id != RTLX_ID) {
pr_err("no valid RTLX id at 0x%p 0x%lx\n", rtlxi, rtlxi->id);
return -ENOEXEC;
}
rtlx = rtlxi;
return 0;
}
/* notifications */
void rtlx_starting(int vpe)
{
int i;
sp_stopping = 0;
/* force a reload of rtlx */
rtlx = NULL;
/* wake up any sleeping rtlx_open's */
for (i = 0; i < RTLX_CHANNELS; i++)
wake_up_interruptible(&channel_wqs[i].lx_queue);
}
void rtlx_stopping(int vpe)
{
int i;
sp_stopping = 1;
for (i = 0; i < RTLX_CHANNELS; i++)
wake_up_interruptible(&channel_wqs[i].lx_queue);
}
int rtlx_open(int index, int can_sleep)
{
struct rtlx_info **p;
struct rtlx_channel *chan;
enum rtlx_state state;
int ret = 0;
if (index >= RTLX_CHANNELS) {
pr_debug("rtlx_open index out of range\n");
return -ENOSYS;
}
if (atomic_inc_return(&channel_wqs[index].in_open) > 1) {
pr_debug("rtlx_open channel %d already opened\n", index);
ret = -EBUSY;
goto out_fail;
}
if (rtlx == NULL) {
p = vpe_get_shared(aprp_cpu_index());
if (p == NULL) {
if (can_sleep) {
ret = __wait_event_interruptible(
channel_wqs[index].lx_queue,
(p = vpe_get_shared(aprp_cpu_index())));
if (ret)
goto out_fail;
} else {
pr_debug("No SP program loaded, and device opened with O_NONBLOCK\n");
ret = -ENOSYS;
goto out_fail;
}
}
smp_rmb();
if (*p == NULL) {
if (can_sleep) {
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(
&channel_wqs[index].lx_queue,
&wait, TASK_INTERRUPTIBLE);
smp_rmb();
if (*p != NULL)
break;
if (!signal_pending(current)) {
schedule();
continue;
}
ret = -ERESTARTSYS;
goto out_fail;
}
finish_wait(&channel_wqs[index].lx_queue,
&wait);
} else {
pr_err(" *vpe_get_shared is NULL. Has an SP program been loaded?\n");
ret = -ENOSYS;
goto out_fail;
}
}
if ((unsigned int)*p < KSEG0) {
pr_warn("vpe_get_shared returned an invalid pointer maybe an error code %d\n",
(int)*p);
ret = -ENOSYS;
goto out_fail;
}
ret = rtlx_init(*p);
if (ret < 0)
goto out_ret;
}
chan = &rtlx->channel[index];
state = xchg(&chan->lx_state, RTLX_STATE_OPENED);
if (state == RTLX_STATE_OPENED) {
ret = -EBUSY;
goto out_fail;
}
out_fail:
smp_mb();
atomic_dec(&channel_wqs[index].in_open);
smp_mb();
out_ret:
return ret;
}
int rtlx_release(int index)
{
if (rtlx == NULL) {
pr_err("rtlx_release() with null rtlx\n");
return 0;
}
rtlx->channel[index].lx_state = RTLX_STATE_UNUSED;
return 0;
}
unsigned int rtlx_read_poll(int index, int can_sleep)
{
struct rtlx_channel *chan;
if (rtlx == NULL)
return 0;
chan = &rtlx->channel[index];
/* data available to read? */
if (chan->lx_read == chan->lx_write) {
if (can_sleep) {
int ret = __wait_event_interruptible(
channel_wqs[index].lx_queue,
(chan->lx_read != chan->lx_write) ||
sp_stopping);
if (ret)
return ret;
if (sp_stopping)
return 0;
} else
return 0;
}
return (chan->lx_write + chan->buffer_size - chan->lx_read)
% chan->buffer_size;
}
static inline int write_spacefree(int read, int write, int size)
{
if (read == write) {
/*
* Never fill the buffer completely, so indexes are always
* equal if empty and only empty, or !equal if data available
*/
return size - 1;
}
return ((read + size - write) % size) - 1;
}
unsigned int rtlx_write_poll(int index)
{
struct rtlx_channel *chan = &rtlx->channel[index];
return write_spacefree(chan->rt_read, chan->rt_write,
chan->buffer_size);
}
ssize_t rtlx_read(int index, void __user *buff, size_t count)
{
size_t lx_write, fl = 0L;
struct rtlx_channel *lx;
unsigned long failed;
if (rtlx == NULL)
return -ENOSYS;
lx = &rtlx->channel[index];
mutex_lock(&channel_wqs[index].mutex);
smp_rmb();
lx_write = lx->lx_write;
/* find out how much in total */
count = min(count,
(size_t)(lx_write + lx->buffer_size - lx->lx_read)
% lx->buffer_size);
/* then how much from the read pointer onwards */
fl = min(count, (size_t)lx->buffer_size - lx->lx_read);
failed = copy_to_user(buff, lx->lx_buffer + lx->lx_read, fl);
if (failed)
goto out;
/* and if there is anything left at the beginning of the buffer */
if (count - fl)
failed = copy_to_user(buff + fl, lx->lx_buffer, count - fl);
out:
count -= failed;
smp_wmb();
lx->lx_read = (lx->lx_read + count) % lx->buffer_size;
smp_wmb();
mutex_unlock(&channel_wqs[index].mutex);
return count;
}
ssize_t rtlx_write(int index, const void __user *buffer, size_t count)
{
struct rtlx_channel *rt;
unsigned long failed;
size_t rt_read;
size_t fl;
if (rtlx == NULL)
return -ENOSYS;
rt = &rtlx->channel[index];
mutex_lock(&channel_wqs[index].mutex);
smp_rmb();
rt_read = rt->rt_read;
/* total number of bytes to copy */
count = min_t(size_t, count, write_spacefree(rt_read, rt->rt_write,
rt->buffer_size));
/* first bit from write pointer to the end of the buffer, or count */
fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
failed = copy_from_user(rt->rt_buffer + rt->rt_write, buffer, fl);
if (failed)
goto out;
/* if there's any left copy to the beginning of the buffer */
if (count - fl)
failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
out:
count -= failed;
smp_wmb();
rt->rt_write = (rt->rt_write + count) % rt->buffer_size;
smp_wmb();
mutex_unlock(&channel_wqs[index].mutex);
_interrupt_sp();
return count;
}
static int file_open(struct inode *inode, struct file *filp)
{
return rtlx_open(iminor(inode), (filp->f_flags & O_NONBLOCK) ? 0 : 1);
}
static int file_release(struct inode *inode, struct file *filp)
{
return rtlx_release(iminor(inode));
}
static __poll_t file_poll(struct file *file, poll_table *wait)
{
int minor = iminor(file_inode(file));
__poll_t mask = 0;
poll_wait(file, &channel_wqs[minor].rt_queue, wait);
poll_wait(file, &channel_wqs[minor].lx_queue, wait);
if (rtlx == NULL)
return 0;
/* data available to read? */
if (rtlx_read_poll(minor, 0))
mask |= EPOLLIN | EPOLLRDNORM;
/* space to write */
if (rtlx_write_poll(minor))
mask |= EPOLLOUT | EPOLLWRNORM;
return mask;
}
static ssize_t file_read(struct file *file, char __user *buffer, size_t count,
loff_t *ppos)
{
int minor = iminor(file_inode(file));
/* data available? */
if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1))
return 0; /* -EAGAIN makes 'cat' whine */
return rtlx_read(minor, buffer, count);
}
static ssize_t file_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
int minor = iminor(file_inode(file));
/* any space left... */
if (!rtlx_write_poll(minor)) {
int ret;
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
ret = __wait_event_interruptible(channel_wqs[minor].rt_queue,
rtlx_write_poll(minor));
if (ret)
return ret;
}
return rtlx_write(minor, buffer, count);
}
const struct file_operations rtlx_fops = {
.owner = THIS_MODULE,
.open = file_open,
.release = file_release,
.write = file_write,
.read = file_read,
.poll = file_poll,
.llseek = noop_llseek,
};
module_init(rtlx_module_init);
module_exit(rtlx_module_exit);
MODULE_DESCRIPTION("MIPS RTLX");
MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
MODULE_LICENSE("GPL");