/*
   * Read-Copy Update tracing for classic implementation
   *
   * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   *
   * Copyright IBM Corporation, 2008
   *
   * Papers:  http://www.rdrop.com/users/paulmck/RCU
   *
   * For detailed explanation of Read-Copy Update mechanism see -

   *		Documentation/RCU

   *
   */
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/init.h>
  #include <linux/spinlock.h>
  #include <linux/smp.h>
  #include <linux/rcupdate.h>
  #include <linux/interrupt.h>
  #include <linux/sched.h>

  #include <linux/atomic.h>

  #include <linux/bitops.h>
  #include <linux/module.h>
  #include <linux/completion.h>
  #include <linux/moduleparam.h>
  #include <linux/percpu.h>
  #include <linux/notifier.h>
  #include <linux/cpu.h>
  #include <linux/mutex.h>
  #include <linux/debugfs.h>
  #include <linux/seq_file.h>

  #define RCU_TREE_NONCORE

  #include "rcutree.h"

  static int r_open(struct inode *inode, struct file *file,
  					const struct seq_operations *op)
  {
  	int ret = seq_open(file, op);
  	if (!ret) {
  		struct seq_file *m = (struct seq_file *)file->private_data;
  		m->private = inode->i_private;
  	}
  	return ret;
  }
  
  static void *r_start(struct seq_file *m, loff_t *pos)
  {
  	struct rcu_state *rsp = (struct rcu_state *)m->private;
  	*pos = cpumask_next(*pos - 1, cpu_possible_mask);
  	if ((*pos) < nr_cpu_ids)
  		return per_cpu_ptr(rsp->rda, *pos);
  	return NULL;
  }
  
  static void *r_next(struct seq_file *m, void *v, loff_t *pos)
  {
  	(*pos)++;
  	return r_start(m, pos);
  }
  
  static void r_stop(struct seq_file *m, void *v)
  {
  }

  static int show_rcubarrier(struct seq_file *m, void *v)

  {
  	struct rcu_state *rsp = (struct rcu_state *)m->private;
  	seq_printf(m, "bcc: %d nbd: %lu
  ",
  		   atomic_read(&rsp->barrier_cpu_count),
  		   rsp->n_barrier_done);
  	return 0;
  }

  static int rcubarrier_open(struct inode *inode, struct file *file)

  {

  	return single_open(file, show_rcubarrier, inode->i_private);

  }

  static const struct file_operations rcubarrier_fops = {

  	.owner = THIS_MODULE,

  	.open = rcubarrier_open,

  	.read = seq_read,
  	.llseek = no_llseek,

  	.release = single_release,

  };

  #ifdef CONFIG_RCU_BOOST

  static char convert_kthread_status(unsigned int kthread_status)
  {
  	if (kthread_status > RCU_KTHREAD_MAX)
  		return '?';

  	return "SRWOY"[kthread_status];

  }

  #endif /* #ifdef CONFIG_RCU_BOOST */

  static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
  {

  	long ql, qll;

  	if (!rdp->beenonline)
  		return;

  	seq_printf(m, "%3d%cc=%ld g=%ld pq=%d qp=%d",

  		   rdp->cpu,
  		   cpu_is_offline(rdp->cpu) ? '!' : ' ',

  		   ulong2long(rdp->completed), ulong2long(rdp->gpnum),

  		   rdp->passed_quiesce, rdp->qs_pending);

  	seq_printf(m, " dt=%d/%llx/%d df=%lu",

  		   atomic_read(&rdp->dynticks->dynticks),

  		   rdp->dynticks->dynticks_nesting,

  		   rdp->dynticks->dynticks_nmi_nesting,

  		   rdp->dynticks_fqs);

  	seq_printf(m, " of=%lu", rdp->offline_fqs);

  	rcu_nocb_q_lengths(rdp, &ql, &qll);
  	qll += rdp->qlen_lazy;
  	ql += rdp->qlen;

  	seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c",

  		   qll, ql,

  		   ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
  			rdp->nxttail[RCU_NEXT_TAIL]],
  		   ".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
  			rdp->nxttail[RCU_NEXT_READY_TAIL]],
  		   ".W"[rdp->nxttail[RCU_DONE_TAIL] !=
  			rdp->nxttail[RCU_WAIT_TAIL]],

  		   ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
  #ifdef CONFIG_RCU_BOOST

  	seq_printf(m, " kt=%d/%c ktl=%x",

  		   per_cpu(rcu_cpu_has_work, rdp->cpu),
  		   convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
  					  rdp->cpu)),

  		   per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
  #endif /* #ifdef CONFIG_RCU_BOOST */
  	seq_printf(m, " b=%ld", rdp->blimit);

  	seq_printf(m, " ci=%lu nci=%lu co=%lu ca=%lu
  ",
  		   rdp->n_cbs_invoked, rdp->n_nocbs_invoked,
  		   rdp->n_cbs_orphaned, rdp->n_cbs_adopted);

  }

  static int show_rcudata(struct seq_file *m, void *v)

  {
  	print_one_rcu_data(m, (struct rcu_data *)v);
  	return 0;
  }

  static const struct seq_operations rcudate_op = {

  	.start = r_start,
  	.next  = r_next,
  	.stop  = r_stop,

  	.show  = show_rcudata,

  };

  static int rcudata_open(struct inode *inode, struct file *file)

  {

  	return r_open(inode, file, &rcudate_op);

  }

  static const struct file_operations rcudata_fops = {

  	.owner = THIS_MODULE,

  	.open = rcudata_open,

  	.read = seq_read,
  	.llseek = no_llseek,
  	.release = seq_release,
  };

  static int show_rcuexp(struct seq_file *m, void *v)
  {
  	struct rcu_state *rsp = (struct rcu_state *)m->private;
  
  	seq_printf(m, "s=%lu d=%lu w=%lu tf=%lu wd1=%lu wd2=%lu n=%lu sc=%lu dt=%lu dl=%lu dx=%lu
  ",
  		   atomic_long_read(&rsp->expedited_start),
  		   atomic_long_read(&rsp->expedited_done),
  		   atomic_long_read(&rsp->expedited_wrap),
  		   atomic_long_read(&rsp->expedited_tryfail),
  		   atomic_long_read(&rsp->expedited_workdone1),
  		   atomic_long_read(&rsp->expedited_workdone2),
  		   atomic_long_read(&rsp->expedited_normal),
  		   atomic_long_read(&rsp->expedited_stoppedcpus),
  		   atomic_long_read(&rsp->expedited_done_tries),
  		   atomic_long_read(&rsp->expedited_done_lost),
  		   atomic_long_read(&rsp->expedited_done_exit));
  	return 0;
  }
  
  static int rcuexp_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, show_rcuexp, inode->i_private);
  }
  
  static const struct file_operations rcuexp_fops = {
  	.owner = THIS_MODULE,
  	.open = rcuexp_open,
  	.read = seq_read,
  	.llseek = no_llseek,

  	.release = single_release,

  };

  #ifdef CONFIG_RCU_BOOST
  
  static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp)
  {

  	seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu ",

  		   rnp->grplo, rnp->grphi,
  		   "T."[list_empty(&rnp->blkd_tasks)],
  		   "N."[!rnp->gp_tasks],
  		   "E."[!rnp->exp_tasks],
  		   "B."[!rnp->boost_tasks],

  		   convert_kthread_status(rnp->boost_kthread_status),

  		   rnp->n_tasks_boosted, rnp->n_exp_boosts,

  		   rnp->n_normal_boosts);
  	seq_printf(m, "j=%04x bt=%04x
  ",

  		   (int)(jiffies & 0xffff),
  		   (int)(rnp->boost_time & 0xffff));

  	seq_printf(m, "    balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu
  ",

  		   rnp->n_balk_blkd_tasks,
  		   rnp->n_balk_exp_gp_tasks,
  		   rnp->n_balk_boost_tasks,
  		   rnp->n_balk_notblocked,
  		   rnp->n_balk_notyet,
  		   rnp->n_balk_nos);
  }
  
  static int show_rcu_node_boost(struct seq_file *m, void *unused)
  {
  	struct rcu_node *rnp;
  
  	rcu_for_each_leaf_node(&rcu_preempt_state, rnp)
  		print_one_rcu_node_boost(m, rnp);
  	return 0;
  }
  
  static int rcu_node_boost_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, show_rcu_node_boost, NULL);
  }
  
  static const struct file_operations rcu_node_boost_fops = {
  	.owner = THIS_MODULE,
  	.open = rcu_node_boost_open,
  	.read = seq_read,

  	.llseek = no_llseek,

  	.release = single_release,
  };

  #endif /* #ifdef CONFIG_RCU_BOOST */

  static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
  {

  	unsigned long gpnum;

  	int level = 0;
  	struct rcu_node *rnp;

  	gpnum = rsp->gpnum;

  	seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x ",
  		   ulong2long(rsp->completed), ulong2long(gpnum),

  		   rsp->fqs_state,

  		   (long)(rsp->jiffies_force_qs - jiffies),

  		   (int)(jiffies & 0xffff));
  	seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld
  ",

  		   rsp->n_force_qs, rsp->n_force_qs_ngp,
  		   rsp->n_force_qs - rsp->n_force_qs_ngp,

  		   rsp->n_force_qs_lh, rsp->qlen_lazy, rsp->qlen);

  	for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {

  		if (rnp->level != level) {
  			seq_puts(m, "
  ");
  			level = rnp->level;
  		}

  		seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d    ",

  			   rnp->qsmask, rnp->qsmaskinit,

  			   ".G"[rnp->gp_tasks != NULL],
  			   ".E"[rnp->exp_tasks != NULL],
  			   ".T"[!list_empty(&rnp->blkd_tasks)],

  			   rnp->grplo, rnp->grphi, rnp->grpnum);
  	}
  	seq_puts(m, "
  ");
  }

  static int show_rcuhier(struct seq_file *m, void *v)

  {

  	struct rcu_state *rsp = (struct rcu_state *)m->private;
  	print_one_rcu_state(m, rsp);

  	return 0;
  }
  
  static int rcuhier_open(struct inode *inode, struct file *file)
  {

  	return single_open(file, show_rcuhier, inode->i_private);

  }

  static const struct file_operations rcuhier_fops = {

  	.owner = THIS_MODULE,
  	.open = rcuhier_open,
  	.read = seq_read,

  	.llseek = no_llseek,

  	.release = single_release,

  };

  static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp)
  {
  	unsigned long flags;
  	unsigned long completed;
  	unsigned long gpnum;
  	unsigned long gpage;
  	unsigned long gpmax;
  	struct rcu_node *rnp = &rsp->node[0];
  
  	raw_spin_lock_irqsave(&rnp->lock, flags);

  	completed = ACCESS_ONCE(rsp->completed);
  	gpnum = ACCESS_ONCE(rsp->gpnum);
  	if (completed == gpnum)

  		gpage = 0;
  	else
  		gpage = jiffies - rsp->gp_start;
  	gpmax = rsp->gp_max;
  	raw_spin_unlock_irqrestore(&rnp->lock, flags);

  	seq_printf(m, "completed=%ld  gpnum=%ld  age=%ld  max=%ld
  ",
  		   ulong2long(completed), ulong2long(gpnum), gpage, gpmax);

  }

  static int show_rcugp(struct seq_file *m, void *v)

  {

  	struct rcu_state *rsp = (struct rcu_state *)m->private;
  	show_one_rcugp(m, rsp);

  	return 0;
  }
  
  static int rcugp_open(struct inode *inode, struct file *file)
  {

  	return single_open(file, show_rcugp, inode->i_private);

  }

  static const struct file_operations rcugp_fops = {

  	.owner = THIS_MODULE,
  	.open = rcugp_open,
  	.read = seq_read,

  	.llseek = no_llseek,

  	.release = single_release,

  };

  static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
  {

  	if (!rdp->beenonline)
  		return;

  	seq_printf(m, "%3d%cnp=%ld ",

  		   rdp->cpu,
  		   cpu_is_offline(rdp->cpu) ? '!' : ' ',

  		   rdp->n_rcu_pending);
  	seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ",

  		   rdp->n_rp_qs_pending,

  		   rdp->n_rp_report_qs,

  		   rdp->n_rp_cb_ready,

  		   rdp->n_rp_cpu_needs_gp);

  	seq_printf(m, "gpc=%ld gps=%ld nn=%ld
  ",

  		   rdp->n_rp_gp_completed,
  		   rdp->n_rp_gp_started,

  		   rdp->n_rp_need_nothing);
  }

  static int show_rcu_pending(struct seq_file *m, void *v)

  {
  	print_one_rcu_pending(m, (struct rcu_data *)v);
  	return 0;
  }

  static const struct seq_operations rcu_pending_op = {

  	.start = r_start,
  	.next  = r_next,
  	.stop  = r_stop,

  	.show  = show_rcu_pending,

  };

  static int rcu_pending_open(struct inode *inode, struct file *file)

  {

  	return r_open(inode, file, &rcu_pending_op);

  }

  static const struct file_operations rcu_pending_fops = {

  	.owner = THIS_MODULE,

  	.open = rcu_pending_open,

  	.read = seq_read,
  	.llseek = no_llseek,
  	.release = seq_release,
  };

  static int show_rcutorture(struct seq_file *m, void *unused)
  {
  	seq_printf(m, "rcutorture test sequence: %lu %s
  ",
  		   rcutorture_testseq >> 1,
  		   (rcutorture_testseq & 0x1) ? "(test in progress)" : "");
  	seq_printf(m, "rcutorture update version number: %lu
  ",
  		   rcutorture_vernum);
  	return 0;
  }
  
  static int rcutorture_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, show_rcutorture, NULL);
  }
  
  static const struct file_operations rcutorture_fops = {
  	.owner = THIS_MODULE,
  	.open = rcutorture_open,
  	.read = seq_read,
  	.llseek = seq_lseek,
  	.release = single_release,
  };

  static struct dentry *rcudir;

  static int __init rcutree_trace_init(void)

  {

  	struct rcu_state *rsp;

  	struct dentry *retval;

  	struct dentry *rspdir;

  	rcudir = debugfs_create_dir("rcu", NULL);
  	if (!rcudir)

  		goto free_out;

  	for_each_rcu_flavor(rsp) {
  		rspdir = debugfs_create_dir(rsp->name, rcudir);
  		if (!rspdir)
  			goto free_out;

  		retval = debugfs_create_file("rcudata", 0444,
  				rspdir, rsp, &rcudata_fops);
  		if (!retval)
  			goto free_out;

  		retval = debugfs_create_file("rcuexp", 0444,
  				rspdir, rsp, &rcuexp_fops);
  		if (!retval)
  			goto free_out;

  		retval = debugfs_create_file("rcu_pending", 0444,
  				rspdir, rsp, &rcu_pending_fops);
  		if (!retval)
  			goto free_out;

  		retval = debugfs_create_file("rcubarrier", 0444,
  				rspdir, rsp, &rcubarrier_fops);
  		if (!retval)
  			goto free_out;

  
  #ifdef CONFIG_RCU_BOOST

  		if (rsp == &rcu_preempt_state) {
  			retval = debugfs_create_file("rcuboost", 0444,
  				rspdir, NULL, &rcu_node_boost_fops);

  			if (!retval)
  				goto free_out;

  		}
  #endif

  		retval = debugfs_create_file("rcugp", 0444,
  				rspdir, rsp, &rcugp_fops);
  		if (!retval)
  			goto free_out;

  		retval = debugfs_create_file("rcuhier", 0444,
  				rspdir, rsp, &rcuhier_fops);
  		if (!retval)
  			goto free_out;
  	}

  	retval = debugfs_create_file("rcutorture", 0444, rcudir,
  						NULL, &rcutorture_fops);
  	if (!retval)
  		goto free_out;

  	return 0;
  free_out:

  	debugfs_remove_recursive(rcudir);

  	return 1;
  }

  static void __exit rcutree_trace_cleanup(void)

  {

  	debugfs_remove_recursive(rcudir);

  }

  module_init(rcutree_trace_init);
  module_exit(rcutree_trace_cleanup);

  
  MODULE_AUTHOR("Paul E. McKenney");
  MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
  MODULE_LICENSE("GPL");