/*
 * 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 <linux/time64.h>
#include "sync.h"

#ifdef CONFIG_DEBUG_FS

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);

void sync_timeline_debug_add(struct sync_timeline *obj)
{
        unsigned long flags;

        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);
}

void sync_timeline_debug_remove(struct sync_timeline *obj)
{
        unsigned long flags;

        spin_lock_irqsave(&sync_timeline_list_lock, flags);
        list_del(&obj->sync_timeline_list);
        spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
}

void sync_fence_debug_add(struct sync_fence *fence)
{
        unsigned long flags;

        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);
}

void sync_fence_debug_remove(struct sync_fence *fence)
{
        unsigned long flags;

        spin_lock_irqsave(&sync_fence_list_lock, flags);
        list_del(&fence->sync_fence_list);
        spin_unlock_irqrestore(&sync_fence_list_lock, flags);
}

static const char *sync_status_str(int status)
{
        if (status == 0)
                return "signaled";

        if (status > 0)
                return "active";

        return "error";
}

static void sync_print_pt(struct seq_file *s, struct fence *pt, bool fence)
{
        int status = 1;

        if (fence_is_signaled_locked(pt))
                status = pt->status;

        seq_printf(s, "  %s%spt %s",
                   fence && pt->ops->get_timeline_name ?
                   pt->ops->get_timeline_name(pt) : "",
                   fence ? "_" : "",
                   sync_status_str(status));

        if (status <= 0) {
                struct timespec64 ts64 =
                        ktime_to_timespec64(pt->timestamp);

                seq_printf(s, "@%lld.%09ld", (s64)ts64.tv_sec, ts64.tv_nsec);
        }

        if ((!fence || pt->ops->timeline_value_str) &&
            pt->ops->fence_value_str) {
                char value[64];
                bool success;

                pt->ops->fence_value_str(pt, value, sizeof(value));
                success = strlen(value);

                if (success)
                        seq_printf(s, ": %s", value);

                if (success && fence) {
                        pt->ops->timeline_value_str(pt, value, sizeof(value));

                        if (strlen(value))
                                seq_printf(s, " / %s", value);
                }
        }

        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);
        }

        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->base, false);
        }
        spin_unlock_irqrestore(&obj->child_list_lock, flags);
}

static void sync_print_fence(struct seq_file *s, struct sync_fence *fence)
{
        wait_queue_t *pos;
        unsigned long flags;
        int i;

        seq_printf(s, "[%p] %s: %s\n", fence, fence->name,
                   sync_status_str(atomic_read(&fence->status)));

        for (i = 0; i < fence->num_fences; ++i) {
                sync_print_pt(s, fence->cbs[i].sync_pt, true);
        }

        spin_lock_irqsave(&fence->wq.lock, flags);
        list_for_each_entry(pos, &fence->wq.task_list, task_list) {
                struct sync_fence_waiter *waiter;

                if (pos->func != &sync_fence_wake_up_wq)
                        continue;

                waiter = container_of(pos, struct sync_fence_waiter, work);

                seq_printf(s, "waiter %pF\n", waiter->callback);
        }
        spin_unlock_irqrestore(&fence->wq.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];
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);
                }
        }
}

#endif