blob: 2996077fedef1673d67725b802b749af80d025b8 [file] [log] [blame]
/*
* drivers/base/sync.c
*
* Copyright (C) 2012 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#include <linux/debugfs.h>
#include <linux/export.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/anon_inodes.h>
#include "sync.h"
#define CREATE_TRACE_POINTS
#include "trace/sync.h"
static void sync_fence_signal_pt(struct sync_pt *pt);
static int _sync_pt_has_signaled(struct sync_pt *pt);
static void sync_fence_free(struct kref *kref);
static void sync_dump(void);
static LIST_HEAD(sync_timeline_list_head);
static DEFINE_SPINLOCK(sync_timeline_list_lock);
static LIST_HEAD(sync_fence_list_head);
static DEFINE_SPINLOCK(sync_fence_list_lock);
struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops,
int size, const char *name)
{
struct sync_timeline *obj;
unsigned long flags;
if (size < sizeof(struct sync_timeline))
return NULL;
obj = kzalloc(size, GFP_KERNEL);
if (obj == NULL)
return NULL;
kref_init(&obj->kref);
obj->ops = ops;
strlcpy(obj->name, name, sizeof(obj->name));
INIT_LIST_HEAD(&obj->child_list_head);
spin_lock_init(&obj->child_list_lock);
INIT_LIST_HEAD(&obj->active_list_head);
spin_lock_init(&obj->active_list_lock);
spin_lock_irqsave(&sync_timeline_list_lock, flags);
list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head);
spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
return obj;
}
EXPORT_SYMBOL(sync_timeline_create);
static void sync_timeline_free(struct kref *kref)
{
struct sync_timeline *obj =
container_of(kref, struct sync_timeline, kref);
unsigned long flags;
if (obj->ops->release_obj)
obj->ops->release_obj(obj);
spin_lock_irqsave(&sync_timeline_list_lock, flags);
list_del(&obj->sync_timeline_list);
spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
kfree(obj);
}
void sync_timeline_destroy(struct sync_timeline *obj)
{
obj->destroyed = true;
/*
* If this is not the last reference, signal any children
* that their parent is going away.
*/
if (!kref_put(&obj->kref, sync_timeline_free))
sync_timeline_signal(obj);
}
EXPORT_SYMBOL(sync_timeline_destroy);
static void sync_timeline_add_pt(struct sync_timeline *obj, struct sync_pt *pt)
{
unsigned long flags;
pt->parent = obj;
spin_lock_irqsave(&obj->child_list_lock, flags);
list_add_tail(&pt->child_list, &obj->child_list_head);
spin_unlock_irqrestore(&obj->child_list_lock, flags);
}
static void sync_timeline_remove_pt(struct sync_pt *pt)
{
struct sync_timeline *obj = pt->parent;
unsigned long flags;
spin_lock_irqsave(&obj->active_list_lock, flags);
if (!list_empty(&pt->active_list))
list_del_init(&pt->active_list);
spin_unlock_irqrestore(&obj->active_list_lock, flags);
spin_lock_irqsave(&obj->child_list_lock, flags);
if (!list_empty(&pt->child_list))
list_del_init(&pt->child_list);
spin_unlock_irqrestore(&obj->child_list_lock, flags);
}
void sync_timeline_signal(struct sync_timeline *obj)
{
unsigned long flags;
LIST_HEAD(signaled_pts);
struct list_head *pos, *n;
trace_sync_timeline(obj);
spin_lock_irqsave(&obj->active_list_lock, flags);
list_for_each_safe(pos, n, &obj->active_list_head) {
struct sync_pt *pt =
container_of(pos, struct sync_pt, active_list);
if (_sync_pt_has_signaled(pt)) {
list_del_init(pos);
list_add(&pt->signaled_list, &signaled_pts);
kref_get(&pt->fence->kref);
}
}
spin_unlock_irqrestore(&obj->active_list_lock, flags);
list_for_each_safe(pos, n, &signaled_pts) {
struct sync_pt *pt =
container_of(pos, struct sync_pt, signaled_list);
list_del_init(pos);
sync_fence_signal_pt(pt);
kref_put(&pt->fence->kref, sync_fence_free);
}
}
EXPORT_SYMBOL(sync_timeline_signal);
struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size)
{
struct sync_pt *pt;
if (size < sizeof(struct sync_pt))
return NULL;
pt = kzalloc(size, GFP_KERNEL);
if (pt == NULL)
return NULL;
INIT_LIST_HEAD(&pt->active_list);
kref_get(&parent->kref);
sync_timeline_add_pt(parent, pt);
return pt;
}
EXPORT_SYMBOL(sync_pt_create);
void sync_pt_free(struct sync_pt *pt)
{
if (pt->parent->ops->free_pt)
pt->parent->ops->free_pt(pt);
sync_timeline_remove_pt(pt);
kref_put(&pt->parent->kref, sync_timeline_free);
kfree(pt);
}
EXPORT_SYMBOL(sync_pt_free);
/* call with pt->parent->active_list_lock held */
static int _sync_pt_has_signaled(struct sync_pt *pt)
{
int old_status = pt->status;
if (!pt->status)
pt->status = pt->parent->ops->has_signaled(pt);
if (!pt->status && pt->parent->destroyed)
pt->status = -ENOENT;
if (pt->status != old_status)
pt->timestamp = ktime_get();
return pt->status;
}
static struct sync_pt *sync_pt_dup(struct sync_pt *pt)
{
return pt->parent->ops->dup(pt);
}
/* Adds a sync pt to the active queue. Called when added to a fence */
static void sync_pt_activate(struct sync_pt *pt)
{
struct sync_timeline *obj = pt->parent;
unsigned long flags;
int err;
spin_lock_irqsave(&obj->active_list_lock, flags);
err = _sync_pt_has_signaled(pt);
if (err != 0)
goto out;
list_add_tail(&pt->active_list, &obj->active_list_head);
out:
spin_unlock_irqrestore(&obj->active_list_lock, flags);
}
static int sync_fence_release(struct inode *inode, struct file *file);
static unsigned int sync_fence_poll(struct file *file, poll_table *wait);
static long sync_fence_ioctl(struct file *file, unsigned int cmd,
unsigned long arg);
static const struct file_operations sync_fence_fops = {
.release = sync_fence_release,
.poll = sync_fence_poll,
.unlocked_ioctl = sync_fence_ioctl,
.compat_ioctl = sync_fence_ioctl,
};
static struct sync_fence *sync_fence_alloc(const char *name)
{
struct sync_fence *fence;
unsigned long flags;
fence = kzalloc(sizeof(struct sync_fence), GFP_KERNEL);
if (fence == NULL)
return NULL;
fence->file = anon_inode_getfile("sync_fence", &sync_fence_fops,
fence, 0);
if (IS_ERR(fence->file))
goto err;
kref_init(&fence->kref);
strlcpy(fence->name, name, sizeof(fence->name));
INIT_LIST_HEAD(&fence->pt_list_head);
INIT_LIST_HEAD(&fence->waiter_list_head);
spin_lock_init(&fence->waiter_list_lock);
init_waitqueue_head(&fence->wq);
spin_lock_irqsave(&sync_fence_list_lock, flags);
list_add_tail(&fence->sync_fence_list, &sync_fence_list_head);
spin_unlock_irqrestore(&sync_fence_list_lock, flags);
return fence;
err:
kfree(fence);
return NULL;
}
/* TODO: implement a create which takes more that one sync_pt */
struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt)
{
struct sync_fence *fence;
if (pt->fence)
return NULL;
fence = sync_fence_alloc(name);
if (fence == NULL)
return NULL;
pt->fence = fence;
list_add(&pt->pt_list, &fence->pt_list_head);
sync_pt_activate(pt);
/*
* signal the fence in case pt was activated before
* sync_pt_activate(pt) was called
*/
sync_fence_signal_pt(pt);
return fence;
}
EXPORT_SYMBOL(sync_fence_create);
static int sync_fence_copy_pts(struct sync_fence *dst, struct sync_fence *src)
{
struct list_head *pos;
list_for_each(pos, &src->pt_list_head) {
struct sync_pt *orig_pt =
container_of(pos, struct sync_pt, pt_list);
struct sync_pt *new_pt = sync_pt_dup(orig_pt);
if (new_pt == NULL)
return -ENOMEM;
new_pt->fence = dst;
list_add(&new_pt->pt_list, &dst->pt_list_head);
}
return 0;
}
static int sync_fence_merge_pts(struct sync_fence *dst, struct sync_fence *src)
{
struct list_head *src_pos, *dst_pos, *n;
list_for_each(src_pos, &src->pt_list_head) {
struct sync_pt *src_pt =
container_of(src_pos, struct sync_pt, pt_list);
bool collapsed = false;
list_for_each_safe(dst_pos, n, &dst->pt_list_head) {
struct sync_pt *dst_pt =
container_of(dst_pos, struct sync_pt, pt_list);
/* collapse two sync_pts on the same timeline
* to a single sync_pt that will signal at
* the later of the two
*/
if (dst_pt->parent == src_pt->parent) {
if (dst_pt->parent->ops->compare(dst_pt, src_pt)
== -1) {
struct sync_pt *new_pt =
sync_pt_dup(src_pt);
if (new_pt == NULL)
return -ENOMEM;
new_pt->fence = dst;
list_replace(&dst_pt->pt_list,
&new_pt->pt_list);
sync_pt_free(dst_pt);
}
collapsed = true;
break;
}
}
if (!collapsed) {
struct sync_pt *new_pt = sync_pt_dup(src_pt);
if (new_pt == NULL)
return -ENOMEM;
new_pt->fence = dst;
list_add(&new_pt->pt_list, &dst->pt_list_head);
}
}
return 0;
}
static void sync_fence_detach_pts(struct sync_fence *fence)
{
struct list_head *pos, *n;
list_for_each_safe(pos, n, &fence->pt_list_head) {
struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list);
sync_timeline_remove_pt(pt);
}
}
static void sync_fence_free_pts(struct sync_fence *fence)
{
struct list_head *pos, *n;
list_for_each_safe(pos, n, &fence->pt_list_head) {
struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list);
sync_pt_free(pt);
}
}
struct sync_fence *sync_fence_fdget(int fd)
{
struct file *file = fget(fd);
if (file == NULL)
return NULL;
if (file->f_op != &sync_fence_fops)
goto err;
return file->private_data;
err:
fput(file);
return NULL;
}
EXPORT_SYMBOL(sync_fence_fdget);
void sync_fence_put(struct sync_fence *fence)
{
fput(fence->file);
}
EXPORT_SYMBOL(sync_fence_put);
void sync_fence_install(struct sync_fence *fence, int fd)
{
fd_install(fd, fence->file);
}
EXPORT_SYMBOL(sync_fence_install);
static int sync_fence_get_status(struct sync_fence *fence)
{
struct list_head *pos;
int status = 1;
list_for_each(pos, &fence->pt_list_head) {
struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list);
int pt_status = pt->status;
if (pt_status < 0) {
status = pt_status;
break;
} else if (status == 1) {
status = pt_status;
}
}
return status;
}
struct sync_fence *sync_fence_merge(const char *name,
struct sync_fence *a, struct sync_fence *b)
{
struct sync_fence *fence;
struct list_head *pos;
int err;
fence = sync_fence_alloc(name);
if (fence == NULL)
return NULL;
err = sync_fence_copy_pts(fence, a);
if (err < 0)
goto err;
err = sync_fence_merge_pts(fence, b);
if (err < 0)
goto err;
list_for_each(pos, &fence->pt_list_head) {
struct sync_pt *pt =
container_of(pos, struct sync_pt, pt_list);
sync_pt_activate(pt);
}
/*
* signal the fence in case one of it's pts were activated before
* they were activated
*/
sync_fence_signal_pt(list_first_entry(&fence->pt_list_head,
struct sync_pt,
pt_list));
return fence;
err:
sync_fence_free_pts(fence);
kfree(fence);
return NULL;
}
EXPORT_SYMBOL(sync_fence_merge);
static void sync_fence_signal_pt(struct sync_pt *pt)
{
LIST_HEAD(signaled_waiters);
struct sync_fence *fence = pt->fence;
struct list_head *pos;
struct list_head *n;
unsigned long flags;
int status;
status = sync_fence_get_status(fence);
spin_lock_irqsave(&fence->waiter_list_lock, flags);
/*
* this should protect against two threads racing on the signaled
* false -> true transition
*/
if (status && !fence->status) {
list_for_each_safe(pos, n, &fence->waiter_list_head)
list_move(pos, &signaled_waiters);
fence->status = status;
} else {
status = 0;
}
spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
if (status) {
list_for_each_safe(pos, n, &signaled_waiters) {
struct sync_fence_waiter *waiter =
container_of(pos, struct sync_fence_waiter,
waiter_list);
list_del(pos);
waiter->callback(fence, waiter);
}
wake_up(&fence->wq);
}
}
int sync_fence_wait_async(struct sync_fence *fence,
struct sync_fence_waiter *waiter)
{
unsigned long flags;
int err = 0;
spin_lock_irqsave(&fence->waiter_list_lock, flags);
if (fence->status) {
err = fence->status;
goto out;
}
list_add_tail(&waiter->waiter_list, &fence->waiter_list_head);
out:
spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
return err;
}
EXPORT_SYMBOL(sync_fence_wait_async);
int sync_fence_cancel_async(struct sync_fence *fence,
struct sync_fence_waiter *waiter)
{
struct list_head *pos;
struct list_head *n;
unsigned long flags;
int ret = -ENOENT;
spin_lock_irqsave(&fence->waiter_list_lock, flags);
/*
* Make sure waiter is still in waiter_list because it is possible for
* the waiter to be removed from the list while the callback is still
* pending.
*/
list_for_each_safe(pos, n, &fence->waiter_list_head) {
struct sync_fence_waiter *list_waiter =
container_of(pos, struct sync_fence_waiter,
waiter_list);
if (list_waiter == waiter) {
list_del(pos);
ret = 0;
break;
}
}
spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
return ret;
}
EXPORT_SYMBOL(sync_fence_cancel_async);
static bool sync_fence_check(struct sync_fence *fence)
{
/*
* Make sure that reads to fence->status are ordered with the
* wait queue event triggering
*/
smp_rmb();
return fence->status != 0;
}
int sync_fence_wait(struct sync_fence *fence, long timeout)
{
int err = 0;
struct sync_pt *pt;
trace_sync_wait(fence, 1);
list_for_each_entry(pt, &fence->pt_list_head, pt_list)
trace_sync_pt(pt);
if (timeout > 0) {
timeout = msecs_to_jiffies(timeout);
err = wait_event_interruptible_timeout(fence->wq,
sync_fence_check(fence),
timeout);
} else if (timeout < 0) {
err = wait_event_interruptible(fence->wq,
sync_fence_check(fence));
}
trace_sync_wait(fence, 0);
if (err < 0)
return err;
if (fence->status < 0) {
pr_info("fence error %d on [%p]\n", fence->status, fence);
sync_dump();
return fence->status;
}
if (fence->status == 0) {
if (timeout > 0) {
pr_info("fence timeout on [%p] after %dms\n", fence,
jiffies_to_msecs(timeout));
sync_dump();
}
return -ETIME;
}
return 0;
}
EXPORT_SYMBOL(sync_fence_wait);
static void sync_fence_free(struct kref *kref)
{
struct sync_fence *fence = container_of(kref, struct sync_fence, kref);
sync_fence_free_pts(fence);
kfree(fence);
}
static int sync_fence_release(struct inode *inode, struct file *file)
{
struct sync_fence *fence = file->private_data;
unsigned long flags;
/*
* We need to remove all ways to access this fence before droping
* our ref.
*
* start with its membership in the global fence list
*/
spin_lock_irqsave(&sync_fence_list_lock, flags);
list_del(&fence->sync_fence_list);
spin_unlock_irqrestore(&sync_fence_list_lock, flags);
/*
* remove its pts from their parents so that sync_timeline_signal()
* can't reference the fence.
*/
sync_fence_detach_pts(fence);
kref_put(&fence->kref, sync_fence_free);
return 0;
}
static unsigned int sync_fence_poll(struct file *file, poll_table *wait)
{
struct sync_fence *fence = file->private_data;
poll_wait(file, &fence->wq, wait);
/*
* Make sure that reads to fence->status are ordered with the
* wait queue event triggering
*/
smp_rmb();
if (fence->status == 1)
return POLLIN;
else if (fence->status < 0)
return POLLERR;
else
return 0;
}
static long sync_fence_ioctl_wait(struct sync_fence *fence, unsigned long arg)
{
__s32 value;
if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
return -EFAULT;
return sync_fence_wait(fence, value);
}
static long sync_fence_ioctl_merge(struct sync_fence *fence, unsigned long arg)
{
int fd = get_unused_fd();
int err;
struct sync_fence *fence2, *fence3;
struct sync_merge_data data;
if (fd < 0)
return fd;
if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
err = -EFAULT;
goto err_put_fd;
}
fence2 = sync_fence_fdget(data.fd2);
if (fence2 == NULL) {
err = -ENOENT;
goto err_put_fd;
}
data.name[sizeof(data.name) - 1] = '\0';
fence3 = sync_fence_merge(data.name, fence, fence2);
if (fence3 == NULL) {
err = -ENOMEM;
goto err_put_fence2;
}
data.fence = fd;
if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
err = -EFAULT;
goto err_put_fence3;
}
sync_fence_install(fence3, fd);
sync_fence_put(fence2);
return 0;
err_put_fence3:
sync_fence_put(fence3);
err_put_fence2:
sync_fence_put(fence2);
err_put_fd:
put_unused_fd(fd);
return err;
}
static int sync_fill_pt_info(struct sync_pt *pt, void *data, int size)
{
struct sync_pt_info *info = data;
int ret;
if (size < sizeof(struct sync_pt_info))
return -ENOMEM;
info->len = sizeof(struct sync_pt_info);
if (pt->parent->ops->fill_driver_data) {
ret = pt->parent->ops->fill_driver_data(pt, info->driver_data,
size - sizeof(*info));
if (ret < 0)
return ret;
info->len += ret;
}
strlcpy(info->obj_name, pt->parent->name, sizeof(info->obj_name));
strlcpy(info->driver_name, pt->parent->ops->driver_name,
sizeof(info->driver_name));
info->status = pt->status;
info->timestamp_ns = ktime_to_ns(pt->timestamp);
return info->len;
}
static long sync_fence_ioctl_fence_info(struct sync_fence *fence,
unsigned long arg)
{
struct sync_fence_info_data *data;
struct list_head *pos;
__u32 size;
__u32 len = 0;
int ret;
if (copy_from_user(&size, (void __user *)arg, sizeof(size)))
return -EFAULT;
if (size < sizeof(struct sync_fence_info_data))
return -EINVAL;
if (size > 4096)
size = 4096;
data = kzalloc(size, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
strlcpy(data->name, fence->name, sizeof(data->name));
data->status = fence->status;
len = sizeof(struct sync_fence_info_data);
list_for_each(pos, &fence->pt_list_head) {
struct sync_pt *pt =
container_of(pos, struct sync_pt, pt_list);
ret = sync_fill_pt_info(pt, (u8 *)data + len, size - len);
if (ret < 0)
goto out;
len += ret;
}
data->len = len;
if (copy_to_user((void __user *)arg, data, len))
ret = -EFAULT;
else
ret = 0;
out:
kfree(data);
return ret;
}
static long sync_fence_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct sync_fence *fence = file->private_data;
switch (cmd) {
case SYNC_IOC_WAIT:
return sync_fence_ioctl_wait(fence, arg);
case SYNC_IOC_MERGE:
return sync_fence_ioctl_merge(fence, arg);
case SYNC_IOC_FENCE_INFO:
return sync_fence_ioctl_fence_info(fence, arg);
default:
return -ENOTTY;
}
}
#ifdef CONFIG_DEBUG_FS
static const char *sync_status_str(int status)
{
if (status > 0)
return "signaled";
else if (status == 0)
return "active";
else
return "error";
}
static void sync_print_pt(struct seq_file *s, struct sync_pt *pt, bool fence)
{
int status = pt->status;
seq_printf(s, " %s%spt %s",
fence ? pt->parent->name : "",
fence ? "_" : "",
sync_status_str(status));
if (pt->status) {
struct timeval tv = ktime_to_timeval(pt->timestamp);
seq_printf(s, "@%ld.%06ld", tv.tv_sec, tv.tv_usec);
}
if (pt->parent->ops->timeline_value_str &&
pt->parent->ops->pt_value_str) {
char value[64];
pt->parent->ops->pt_value_str(pt, value, sizeof(value));
seq_printf(s, ": %s", value);
if (fence) {
pt->parent->ops->timeline_value_str(pt->parent, value,
sizeof(value));
seq_printf(s, " / %s", value);
}
} else if (pt->parent->ops->print_pt) {
seq_puts(s, ": ");
pt->parent->ops->print_pt(s, pt);
}
seq_puts(s, "\n");
}
static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
{
struct list_head *pos;
unsigned long flags;
seq_printf(s, "%s %s", obj->name, obj->ops->driver_name);
if (obj->ops->timeline_value_str) {
char value[64];
obj->ops->timeline_value_str(obj, value, sizeof(value));
seq_printf(s, ": %s", value);
} else if (obj->ops->print_obj) {
seq_puts(s, ": ");
obj->ops->print_obj(s, obj);
}
seq_puts(s, "\n");
spin_lock_irqsave(&obj->child_list_lock, flags);
list_for_each(pos, &obj->child_list_head) {
struct sync_pt *pt =
container_of(pos, struct sync_pt, child_list);
sync_print_pt(s, pt, false);
}
spin_unlock_irqrestore(&obj->child_list_lock, flags);
}
static void sync_print_fence(struct seq_file *s, struct sync_fence *fence)
{
struct list_head *pos;
unsigned long flags;
seq_printf(s, "[%p] %s: %s\n", fence, fence->name,
sync_status_str(fence->status));
list_for_each(pos, &fence->pt_list_head) {
struct sync_pt *pt =
container_of(pos, struct sync_pt, pt_list);
sync_print_pt(s, pt, true);
}
spin_lock_irqsave(&fence->waiter_list_lock, flags);
list_for_each(pos, &fence->waiter_list_head) {
struct sync_fence_waiter *waiter =
container_of(pos, struct sync_fence_waiter,
waiter_list);
seq_printf(s, "waiter %pF\n", waiter->callback);
}
spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
}
static int sync_debugfs_show(struct seq_file *s, void *unused)
{
unsigned long flags;
struct list_head *pos;
seq_puts(s, "objs:\n--------------\n");
spin_lock_irqsave(&sync_timeline_list_lock, flags);
list_for_each(pos, &sync_timeline_list_head) {
struct sync_timeline *obj =
container_of(pos, struct sync_timeline,
sync_timeline_list);
sync_print_obj(s, obj);
seq_puts(s, "\n");
}
spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
seq_puts(s, "fences:\n--------------\n");
spin_lock_irqsave(&sync_fence_list_lock, flags);
list_for_each(pos, &sync_fence_list_head) {
struct sync_fence *fence =
container_of(pos, struct sync_fence, sync_fence_list);
sync_print_fence(s, fence);
seq_puts(s, "\n");
}
spin_unlock_irqrestore(&sync_fence_list_lock, flags);
return 0;
}
static int sync_debugfs_open(struct inode *inode, struct file *file)
{
return single_open(file, sync_debugfs_show, inode->i_private);
}
static const struct file_operations sync_debugfs_fops = {
.open = sync_debugfs_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static __init int sync_debugfs_init(void)
{
debugfs_create_file("sync", S_IRUGO, NULL, NULL, &sync_debugfs_fops);
return 0;
}
late_initcall(sync_debugfs_init);
#define DUMP_CHUNK 256
static char sync_dump_buf[64 * 1024];
static void sync_dump(void)
{
struct seq_file s = {
.buf = sync_dump_buf,
.size = sizeof(sync_dump_buf) - 1,
};
int i;
sync_debugfs_show(&s, NULL);
for (i = 0; i < s.count; i += DUMP_CHUNK) {
if ((s.count - i) > DUMP_CHUNK) {
char c = s.buf[i + DUMP_CHUNK];
s.buf[i + DUMP_CHUNK] = 0;
pr_cont("%s", s.buf + i);
s.buf[i + DUMP_CHUNK] = c;
} else {
s.buf[s.count] = 0;
pr_cont("%s", s.buf + i);
}
}
}
#else
static void sync_dump(void)
{
}
#endif