/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 *
 *   This file is part of Portals
 *   http://sourceforge.net/projects/sandiaportals/
 *
 *   Portals is free software; you can redistribute it and/or
 *   modify it under the terms of version 2 of the GNU General Public
 *   License as published by the Free Software Foundation.
 *
 *   Portals 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 Portals; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#define DEBUG_SUBSYSTEM S_LNET
#include "../../include/linux/libcfs/libcfs.h"
#include "../../include/linux/lnet/lib-lnet.h"

#if  defined(LNET_ROUTER)

/* This is really lnet_proc.c. You might need to update sanity test 215
 * if any file format is changed. */

static struct ctl_table_header *lnet_table_header;

#define LNET_LOFFT_BITS		(sizeof(loff_t) * 8)
/*
 * NB: max allowed LNET_CPT_BITS is 8 on 64-bit system and 2 on 32-bit system
 */
#define LNET_PROC_CPT_BITS	(LNET_CPT_BITS + 1)
/* change version, 16 bits or 8 bits */
#define LNET_PROC_VER_BITS	max_t(size_t, min_t(size_t, LNET_LOFFT_BITS, 64) / 4, 8)

#define LNET_PROC_HASH_BITS	LNET_PEER_HASH_BITS
/*
 * bits for peer hash offset
 * NB: we don't use the highest bit of *ppos because it's signed
 */
#define LNET_PROC_HOFF_BITS	(LNET_LOFFT_BITS -       \
				 LNET_PROC_CPT_BITS -    \
				 LNET_PROC_VER_BITS -    \
				 LNET_PROC_HASH_BITS - 1)
/* bits for hash index + position */
#define LNET_PROC_HPOS_BITS	(LNET_PROC_HASH_BITS + LNET_PROC_HOFF_BITS)
/* bits for peer hash table + hash version */
#define LNET_PROC_VPOS_BITS	(LNET_PROC_HPOS_BITS + LNET_PROC_VER_BITS)

#define LNET_PROC_CPT_MASK	((1ULL << LNET_PROC_CPT_BITS) - 1)
#define LNET_PROC_VER_MASK	((1ULL << LNET_PROC_VER_BITS) - 1)
#define LNET_PROC_HASH_MASK	((1ULL << LNET_PROC_HASH_BITS) - 1)
#define LNET_PROC_HOFF_MASK	((1ULL << LNET_PROC_HOFF_BITS) - 1)

#define LNET_PROC_CPT_GET(pos)				\
	(int)(((pos) >> LNET_PROC_VPOS_BITS) & LNET_PROC_CPT_MASK)

#define LNET_PROC_VER_GET(pos)				\
	(int)(((pos) >> LNET_PROC_HPOS_BITS) & LNET_PROC_VER_MASK)

#define LNET_PROC_HASH_GET(pos)				\
	(int)(((pos) >> LNET_PROC_HOFF_BITS) & LNET_PROC_HASH_MASK)

#define LNET_PROC_HOFF_GET(pos)				\
	(int)((pos) & LNET_PROC_HOFF_MASK)

#define LNET_PROC_POS_MAKE(cpt, ver, hash, off)		\
	(((((loff_t)(cpt)) & LNET_PROC_CPT_MASK) << LNET_PROC_VPOS_BITS) |   \
	((((loff_t)(ver)) & LNET_PROC_VER_MASK) << LNET_PROC_HPOS_BITS) |   \
	((((loff_t)(hash)) & LNET_PROC_HASH_MASK) << LNET_PROC_HOFF_BITS) | \
	((off) & LNET_PROC_HOFF_MASK))

#define LNET_PROC_VERSION(v)	((unsigned int)((v) & LNET_PROC_VER_MASK))

static int proc_call_handler(void *data, int write, loff_t *ppos,
		void __user *buffer, size_t *lenp,
		int (*handler)(void *data, int write,
		loff_t pos, void __user *buffer, int len))
{
	int rc = handler(data, write, *ppos, buffer, *lenp);

	if (rc < 0)
		return rc;

	if (write) {
		*ppos += *lenp;
	} else {
		*lenp = rc;
		*ppos += rc;
	}
	return 0;
}

static int __proc_lnet_stats(void *data, int write,
			     loff_t pos, void __user *buffer, int nob)
{
	int rc;
	lnet_counters_t *ctrs;
	int len;
	char *tmpstr;
	const int tmpsiz = 256; /* 7 %u and 4 %llu */

	if (write) {
		lnet_counters_reset();
		return 0;
	}

	/* read */

	LIBCFS_ALLOC(ctrs, sizeof(*ctrs));
	if (ctrs == NULL)
		return -ENOMEM;

	LIBCFS_ALLOC(tmpstr, tmpsiz);
	if (tmpstr == NULL) {
		LIBCFS_FREE(ctrs, sizeof(*ctrs));
		return -ENOMEM;
	}

	lnet_counters_get(ctrs);

	len = snprintf(tmpstr, tmpsiz,
		       "%u %u %u %u %u %u %u %llu %llu %llu %llu",
		       ctrs->msgs_alloc, ctrs->msgs_max,
		       ctrs->errors,
		       ctrs->send_count, ctrs->recv_count,
		       ctrs->route_count, ctrs->drop_count,
		       ctrs->send_length, ctrs->recv_length,
		       ctrs->route_length, ctrs->drop_length);

	if (pos >= min_t(int, len, strlen(tmpstr)))
		rc = 0;
	else
		rc = cfs_trace_copyout_string(buffer, nob,
					      tmpstr + pos, "\n");

	LIBCFS_FREE(tmpstr, tmpsiz);
	LIBCFS_FREE(ctrs, sizeof(*ctrs));
	return rc;
}

static int proc_lnet_stats(struct ctl_table *table, int write,
			   void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return proc_call_handler(table->data, write, ppos, buffer, lenp,
				 __proc_lnet_stats);
}

static int proc_lnet_routes(struct ctl_table *table, int write,
			    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	const int tmpsiz = 256;
	char *tmpstr;
	char *s;
	int rc = 0;
	int len;
	int ver;
	int off;

	CLASSERT(sizeof(loff_t) >= 4);

	off = LNET_PROC_HOFF_GET(*ppos);
	ver = LNET_PROC_VER_GET(*ppos);

	LASSERT(!write);

	if (*lenp == 0)
		return 0;

	LIBCFS_ALLOC(tmpstr, tmpsiz);
	if (tmpstr == NULL)
		return -ENOMEM;

	s = tmpstr; /* points to current position in tmpstr[] */

	if (*ppos == 0) {
		s += snprintf(s, tmpstr + tmpsiz - s, "Routing %s\n",
			      the_lnet.ln_routing ? "enabled" : "disabled");
		LASSERT(tmpstr + tmpsiz - s > 0);

		s += snprintf(s, tmpstr + tmpsiz - s, "%-8s %4s %8s %7s %s\n",
			      "net", "hops", "priority", "state", "router");
		LASSERT(tmpstr + tmpsiz - s > 0);

		lnet_net_lock(0);
		ver = (unsigned int)the_lnet.ln_remote_nets_version;
		lnet_net_unlock(0);
		*ppos = LNET_PROC_POS_MAKE(0, ver, 0, off);
	} else {
		struct list_head *n;
		struct list_head *r;
		lnet_route_t *route = NULL;
		lnet_remotenet_t *rnet  = NULL;
		int skip  = off - 1;
		struct list_head *rn_list;
		int i;

		lnet_net_lock(0);

		if (ver != LNET_PROC_VERSION(the_lnet.ln_remote_nets_version)) {
			lnet_net_unlock(0);
			LIBCFS_FREE(tmpstr, tmpsiz);
			return -ESTALE;
		}

		for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE && route == NULL;
		     i++) {
			rn_list = &the_lnet.ln_remote_nets_hash[i];

			n = rn_list->next;

			while (n != rn_list && route == NULL) {
				rnet = list_entry(n, lnet_remotenet_t,
						      lrn_list);

				r = rnet->lrn_routes.next;

				while (r != &rnet->lrn_routes) {
					lnet_route_t *re =
						list_entry(r, lnet_route_t,
							       lr_list);
					if (skip == 0) {
						route = re;
						break;
					}

					skip--;
					r = r->next;
				}

				n = n->next;
			}
		}

		if (route != NULL) {
			__u32 net = rnet->lrn_net;
			unsigned int hops = route->lr_hops;
			unsigned int priority = route->lr_priority;
			lnet_nid_t nid = route->lr_gateway->lp_nid;
			int alive = route->lr_gateway->lp_alive;

			s += snprintf(s, tmpstr + tmpsiz - s,
				      "%-8s %4u %8u %7s %s\n",
				      libcfs_net2str(net), hops,
				      priority,
				      alive ? "up" : "down",
				      libcfs_nid2str(nid));
			LASSERT(tmpstr + tmpsiz - s > 0);
		}

		lnet_net_unlock(0);
	}

	len = s - tmpstr;     /* how many bytes was written */

	if (len > *lenp) {    /* linux-supplied buffer is too small */
		rc = -EINVAL;
	} else if (len > 0) { /* wrote something */
		if (copy_to_user(buffer, tmpstr, len))
			rc = -EFAULT;
		else {
			off += 1;
			*ppos = LNET_PROC_POS_MAKE(0, ver, 0, off);
		}
	}

	LIBCFS_FREE(tmpstr, tmpsiz);

	if (rc == 0)
		*lenp = len;

	return rc;
}

static int proc_lnet_routers(struct ctl_table *table, int write,
			     void __user *buffer, size_t *lenp, loff_t *ppos)
{
	int rc = 0;
	char *tmpstr;
	char *s;
	const int tmpsiz = 256;
	int len;
	int ver;
	int off;

	off = LNET_PROC_HOFF_GET(*ppos);
	ver = LNET_PROC_VER_GET(*ppos);

	LASSERT(!write);

	if (*lenp == 0)
		return 0;

	LIBCFS_ALLOC(tmpstr, tmpsiz);
	if (tmpstr == NULL)
		return -ENOMEM;

	s = tmpstr; /* points to current position in tmpstr[] */

	if (*ppos == 0) {
		s += snprintf(s, tmpstr + tmpsiz - s,
			      "%-4s %7s %9s %6s %12s %9s %8s %7s %s\n",
			      "ref", "rtr_ref", "alive_cnt", "state",
			      "last_ping", "ping_sent", "deadline",
			      "down_ni", "router");
		LASSERT(tmpstr + tmpsiz - s > 0);

		lnet_net_lock(0);
		ver = (unsigned int)the_lnet.ln_routers_version;
		lnet_net_unlock(0);
		*ppos = LNET_PROC_POS_MAKE(0, ver, 0, off);
	} else {
		struct list_head *r;
		struct lnet_peer *peer = NULL;
		int skip = off - 1;

		lnet_net_lock(0);

		if (ver != LNET_PROC_VERSION(the_lnet.ln_routers_version)) {
			lnet_net_unlock(0);

			LIBCFS_FREE(tmpstr, tmpsiz);
			return -ESTALE;
		}

		r = the_lnet.ln_routers.next;

		while (r != &the_lnet.ln_routers) {
			lnet_peer_t *lp = list_entry(r, lnet_peer_t,
							 lp_rtr_list);

			if (skip == 0) {
				peer = lp;
				break;
			}

			skip--;
			r = r->next;
		}

		if (peer != NULL) {
			lnet_nid_t nid = peer->lp_nid;
			unsigned long now = cfs_time_current();
			unsigned long deadline = peer->lp_ping_deadline;
			int nrefs = peer->lp_refcount;
			int nrtrrefs = peer->lp_rtr_refcount;
			int alive_cnt = peer->lp_alive_count;
			int alive = peer->lp_alive;
			int pingsent = !peer->lp_ping_notsent;
			int last_ping = cfs_duration_sec(cfs_time_sub(now,
						     peer->lp_ping_timestamp));
			int down_ni = 0;
			lnet_route_t *rtr;

			if ((peer->lp_ping_feats &
			     LNET_PING_FEAT_NI_STATUS) != 0) {
				list_for_each_entry(rtr, &peer->lp_routes,
							lr_gwlist) {
					/* downis on any route should be the
					 * number of downis on the gateway */
					if (rtr->lr_downis != 0) {
						down_ni = rtr->lr_downis;
						break;
					}
				}
			}

			if (deadline == 0)
				s += snprintf(s, tmpstr + tmpsiz - s,
					      "%-4d %7d %9d %6s %12d %9d %8s %7d %s\n",
					      nrefs, nrtrrefs, alive_cnt,
					      alive ? "up" : "down", last_ping,
					      pingsent, "NA", down_ni,
					      libcfs_nid2str(nid));
			else
				s += snprintf(s, tmpstr + tmpsiz - s,
					      "%-4d %7d %9d %6s %12d %9d %8lu %7d %s\n",
					      nrefs, nrtrrefs, alive_cnt,
					      alive ? "up" : "down", last_ping,
					      pingsent,
					      cfs_duration_sec(cfs_time_sub(deadline, now)),
					      down_ni, libcfs_nid2str(nid));
			LASSERT(tmpstr + tmpsiz - s > 0);
		}

		lnet_net_unlock(0);
	}

	len = s - tmpstr;     /* how many bytes was written */

	if (len > *lenp) {    /* linux-supplied buffer is too small */
		rc = -EINVAL;
	} else if (len > 0) { /* wrote something */
		if (copy_to_user(buffer, tmpstr, len))
			rc = -EFAULT;
		else {
			off += 1;
			*ppos = LNET_PROC_POS_MAKE(0, ver, 0, off);
		}
	}

	LIBCFS_FREE(tmpstr, tmpsiz);

	if (rc == 0)
		*lenp = len;

	return rc;
}

static int proc_lnet_peers(struct ctl_table *table, int write,
			   void __user *buffer, size_t *lenp, loff_t *ppos)
{
	const int tmpsiz  = 256;
	struct lnet_peer_table *ptable;
	char *tmpstr;
	char *s;
	int cpt  = LNET_PROC_CPT_GET(*ppos);
	int ver  = LNET_PROC_VER_GET(*ppos);
	int hash = LNET_PROC_HASH_GET(*ppos);
	int hoff = LNET_PROC_HOFF_GET(*ppos);
	int rc = 0;
	int len;

	CLASSERT(LNET_PROC_HASH_BITS >= LNET_PEER_HASH_BITS);
	LASSERT(!write);

	if (*lenp == 0)
		return 0;

	if (cpt >= LNET_CPT_NUMBER) {
		*lenp = 0;
		return 0;
	}

	LIBCFS_ALLOC(tmpstr, tmpsiz);
	if (tmpstr == NULL)
		return -ENOMEM;

	s = tmpstr; /* points to current position in tmpstr[] */

	if (*ppos == 0) {
		s += snprintf(s, tmpstr + tmpsiz - s,
			      "%-24s %4s %5s %5s %5s %5s %5s %5s %5s %s\n",
			      "nid", "refs", "state", "last", "max",
			      "rtr", "min", "tx", "min", "queue");
		LASSERT(tmpstr + tmpsiz - s > 0);

		hoff++;
	} else {
		struct lnet_peer *peer;
		struct list_head *p;
		int skip;
 again:
		p = NULL;
		peer = NULL;
		skip = hoff - 1;

		lnet_net_lock(cpt);
		ptable = the_lnet.ln_peer_tables[cpt];
		if (hoff == 1)
			ver = LNET_PROC_VERSION(ptable->pt_version);

		if (ver != LNET_PROC_VERSION(ptable->pt_version)) {
			lnet_net_unlock(cpt);
			LIBCFS_FREE(tmpstr, tmpsiz);
			return -ESTALE;
		}

		while (hash < LNET_PEER_HASH_SIZE) {
			if (p == NULL)
				p = ptable->pt_hash[hash].next;

			while (p != &ptable->pt_hash[hash]) {
				lnet_peer_t *lp = list_entry(p, lnet_peer_t,
								 lp_hashlist);
				if (skip == 0) {
					peer = lp;

					/* minor optimization: start from idx+1
					 * on next iteration if we've just
					 * drained lp_hashlist */
					if (lp->lp_hashlist.next ==
					    &ptable->pt_hash[hash]) {
						hoff = 1;
						hash++;
					} else {
						hoff++;
					}

					break;
				}

				skip--;
				p = lp->lp_hashlist.next;
			}

			if (peer != NULL)
				break;

			p = NULL;
			hoff = 1;
			hash++;
		}

		if (peer != NULL) {
			lnet_nid_t nid = peer->lp_nid;
			int nrefs = peer->lp_refcount;
			int lastalive = -1;
			char *aliveness = "NA";
			int maxcr = peer->lp_ni->ni_peertxcredits;
			int txcr = peer->lp_txcredits;
			int mintxcr = peer->lp_mintxcredits;
			int rtrcr = peer->lp_rtrcredits;
			int minrtrcr = peer->lp_minrtrcredits;
			int txqnob = peer->lp_txqnob;

			if (lnet_isrouter(peer) ||
			    lnet_peer_aliveness_enabled(peer))
				aliveness = peer->lp_alive ? "up" : "down";

			if (lnet_peer_aliveness_enabled(peer)) {
				unsigned long now = cfs_time_current();
				long delta;

				delta = cfs_time_sub(now, peer->lp_last_alive);
				lastalive = cfs_duration_sec(delta);

				/* No need to mess up peers contents with
				 * arbitrarily long integers - it suffices to
				 * know that lastalive is more than 10000s old
				 */
				if (lastalive >= 10000)
					lastalive = 9999;
			}

			lnet_net_unlock(cpt);

			s += snprintf(s, tmpstr + tmpsiz - s,
				      "%-24s %4d %5s %5d %5d %5d %5d %5d %5d %d\n",
				      libcfs_nid2str(nid), nrefs, aliveness,
				      lastalive, maxcr, rtrcr, minrtrcr, txcr,
				      mintxcr, txqnob);
			LASSERT(tmpstr + tmpsiz - s > 0);

		} else { /* peer is NULL */
			lnet_net_unlock(cpt);
		}

		if (hash == LNET_PEER_HASH_SIZE) {
			cpt++;
			hash = 0;
			hoff = 1;
			if (peer == NULL && cpt < LNET_CPT_NUMBER)
				goto again;
		}
	}

	len = s - tmpstr;     /* how many bytes was written */

	if (len > *lenp) {    /* linux-supplied buffer is too small */
		rc = -EINVAL;
	} else if (len > 0) { /* wrote something */
		if (copy_to_user(buffer, tmpstr, len))
			rc = -EFAULT;
		else
			*ppos = LNET_PROC_POS_MAKE(cpt, ver, hash, hoff);
	}

	LIBCFS_FREE(tmpstr, tmpsiz);

	if (rc == 0)
		*lenp = len;

	return rc;
}

static int __proc_lnet_buffers(void *data, int write,
			       loff_t pos, void __user *buffer, int nob)
{
	char *s;
	char *tmpstr;
	int tmpsiz;
	int idx;
	int len;
	int rc;
	int i;

	LASSERT(!write);

	/* (4 %d) * 4 * LNET_CPT_NUMBER */
	tmpsiz = 64 * (LNET_NRBPOOLS + 1) * LNET_CPT_NUMBER;
	LIBCFS_ALLOC(tmpstr, tmpsiz);
	if (tmpstr == NULL)
		return -ENOMEM;

	s = tmpstr; /* points to current position in tmpstr[] */

	s += snprintf(s, tmpstr + tmpsiz - s,
		      "%5s %5s %7s %7s\n",
		      "pages", "count", "credits", "min");
	LASSERT(tmpstr + tmpsiz - s > 0);

	if (the_lnet.ln_rtrpools == NULL)
		goto out; /* I'm not a router */

	for (idx = 0; idx < LNET_NRBPOOLS; idx++) {
		lnet_rtrbufpool_t *rbp;

		lnet_net_lock(LNET_LOCK_EX);
		cfs_percpt_for_each(rbp, i, the_lnet.ln_rtrpools) {
			s += snprintf(s, tmpstr + tmpsiz - s,
				      "%5d %5d %7d %7d\n",
				      rbp[idx].rbp_npages,
				      rbp[idx].rbp_nbuffers,
				      rbp[idx].rbp_credits,
				      rbp[idx].rbp_mincredits);
			LASSERT(tmpstr + tmpsiz - s > 0);
		}
		lnet_net_unlock(LNET_LOCK_EX);
	}

 out:
	len = s - tmpstr;

	if (pos >= min_t(int, len, strlen(tmpstr)))
		rc = 0;
	else
		rc = cfs_trace_copyout_string(buffer, nob,
					      tmpstr + pos, NULL);

	LIBCFS_FREE(tmpstr, tmpsiz);
	return rc;
}

static int proc_lnet_buffers(struct ctl_table *table, int write,
			     void __user *buffer, size_t *lenp, loff_t *ppos)
{
	return proc_call_handler(table->data, write, ppos, buffer, lenp,
				 __proc_lnet_buffers);
}

static int proc_lnet_nis(struct ctl_table *table, int write,
			 void __user *buffer, size_t *lenp, loff_t *ppos)
{
	int tmpsiz = 128 * LNET_CPT_NUMBER;
	int rc = 0;
	char *tmpstr;
	char *s;
	int len;

	LASSERT(!write);

	if (*lenp == 0)
		return 0;

	LIBCFS_ALLOC(tmpstr, tmpsiz);
	if (tmpstr == NULL)
		return -ENOMEM;

	s = tmpstr; /* points to current position in tmpstr[] */

	if (*ppos == 0) {
		s += snprintf(s, tmpstr + tmpsiz - s,
			      "%-24s %6s %5s %4s %4s %4s %5s %5s %5s\n",
			      "nid", "status", "alive", "refs", "peer",
			      "rtr", "max", "tx", "min");
		LASSERT(tmpstr + tmpsiz - s > 0);
	} else {
		struct list_head *n;
		lnet_ni_t *ni   = NULL;
		int skip = *ppos - 1;

		lnet_net_lock(0);

		n = the_lnet.ln_nis.next;

		while (n != &the_lnet.ln_nis) {
			lnet_ni_t *a_ni = list_entry(n, lnet_ni_t, ni_list);

			if (skip == 0) {
				ni = a_ni;
				break;
			}

			skip--;
			n = n->next;
		}

		if (ni != NULL) {
			struct lnet_tx_queue *tq;
			char *stat;
			long now = get_seconds();
			int last_alive = -1;
			int i;
			int j;

			if (the_lnet.ln_routing)
				last_alive = now - ni->ni_last_alive;

			/* @lo forever alive */
			if (ni->ni_lnd->lnd_type == LOLND)
				last_alive = 0;

			lnet_ni_lock(ni);
			LASSERT(ni->ni_status != NULL);
			stat = (ni->ni_status->ns_status ==
				LNET_NI_STATUS_UP) ? "up" : "down";
			lnet_ni_unlock(ni);

			/* we actually output credits information for
			 * TX queue of each partition */
			cfs_percpt_for_each(tq, i, ni->ni_tx_queues) {
				for (j = 0; ni->ni_cpts != NULL &&
				     j < ni->ni_ncpts; j++) {
					if (i == ni->ni_cpts[j])
						break;
				}

				if (j == ni->ni_ncpts)
					continue;

				if (i != 0)
					lnet_net_lock(i);

				s += snprintf(s, tmpstr + tmpsiz - s,
				      "%-24s %6s %5d %4d %4d %4d %5d %5d %5d\n",
				      libcfs_nid2str(ni->ni_nid), stat,
				      last_alive, *ni->ni_refs[i],
				      ni->ni_peertxcredits,
				      ni->ni_peerrtrcredits,
				      tq->tq_credits_max,
				      tq->tq_credits, tq->tq_credits_min);
				if (i != 0)
					lnet_net_unlock(i);
			}
			LASSERT(tmpstr + tmpsiz - s > 0);
		}

		lnet_net_unlock(0);
	}

	len = s - tmpstr;     /* how many bytes was written */

	if (len > *lenp) {    /* linux-supplied buffer is too small */
		rc = -EINVAL;
	} else if (len > 0) { /* wrote something */
		if (copy_to_user(buffer, tmpstr, len))
			rc = -EFAULT;
		else
			*ppos += 1;
	}

	LIBCFS_FREE(tmpstr, tmpsiz);

	if (rc == 0)
		*lenp = len;

	return rc;
}

struct lnet_portal_rotors {
	int pr_value;
	const char *pr_name;
	const char *pr_desc;
};

static struct lnet_portal_rotors	portal_rotors[] = {
	{
		.pr_value = LNET_PTL_ROTOR_OFF,
		.pr_name  = "OFF",
		.pr_desc  = "Turn off message rotor for wildcard portals"
	},
	{
		.pr_value = LNET_PTL_ROTOR_ON,
		.pr_name  = "ON",
		.pr_desc  = "round-robin dispatch all PUT messages for wildcard portals"
	},
	{
		.pr_value = LNET_PTL_ROTOR_RR_RT,
		.pr_name  = "RR_RT",
		.pr_desc  = "round-robin dispatch routed PUT message for wildcard portals"
	},
	{
		.pr_value = LNET_PTL_ROTOR_HASH_RT,
		.pr_name  = "HASH_RT",
		.pr_desc  = "dispatch routed PUT message by hashing source NID for wildcard portals"
	},
	{
		.pr_value = -1,
		.pr_name  = NULL,
		.pr_desc  = NULL
	},
};

extern int portal_rotor;

static int __proc_lnet_portal_rotor(void *data, int write,
				    loff_t pos, void __user *buffer, int nob)
{
	const int buf_len = 128;
	char *buf;
	char *tmp;
	int rc;
	int i;

	LIBCFS_ALLOC(buf, buf_len);
	if (buf == NULL)
		return -ENOMEM;

	if (!write) {
		lnet_res_lock(0);

		for (i = 0; portal_rotors[i].pr_value >= 0; i++) {
			if (portal_rotors[i].pr_value == portal_rotor)
				break;
		}

		LASSERT(portal_rotors[i].pr_value == portal_rotor);
		lnet_res_unlock(0);

		rc = snprintf(buf, buf_len,
			      "{\n\tportals: all\n"
			      "\trotor: %s\n\tdescription: %s\n}",
			      portal_rotors[i].pr_name,
			      portal_rotors[i].pr_desc);

		if (pos >= min_t(int, rc, buf_len)) {
			rc = 0;
		} else {
			rc = cfs_trace_copyout_string(buffer, nob,
					buf + pos, "\n");
		}
		goto out;
	}

	rc = cfs_trace_copyin_string(buf, buf_len, buffer, nob);
	if (rc < 0)
		goto out;

	tmp = cfs_trimwhite(buf);

	rc = -EINVAL;
	lnet_res_lock(0);
	for (i = 0; portal_rotors[i].pr_name != NULL; i++) {
		if (strncasecmp(portal_rotors[i].pr_name, tmp,
				strlen(portal_rotors[i].pr_name)) == 0) {
			portal_rotor = portal_rotors[i].pr_value;
			rc = 0;
			break;
		}
	}
	lnet_res_unlock(0);
out:
	LIBCFS_FREE(buf, buf_len);
	return rc;
}

static int proc_lnet_portal_rotor(struct ctl_table *table, int write,
				  void __user *buffer, size_t *lenp,
				  loff_t *ppos)
{
	return proc_call_handler(table->data, write, ppos, buffer, lenp,
				 __proc_lnet_portal_rotor);
}

static struct ctl_table lnet_table[] = {
	/*
	 * NB No .strategy entries have been provided since sysctl(8) prefers
	 * to go via /proc for portability.
	 */
	{
		.procname     = "stats",
		.mode         = 0644,
		.proc_handler = &proc_lnet_stats,
	},
	{
		.procname     = "routes",
		.mode         = 0444,
		.proc_handler = &proc_lnet_routes,
	},
	{
		.procname     = "routers",
		.mode         = 0444,
		.proc_handler = &proc_lnet_routers,
	},
	{
		.procname     = "peers",
		.mode         = 0444,
		.proc_handler = &proc_lnet_peers,
	},
	{
		.procname     = "buffers",
		.mode         = 0444,
		.proc_handler = &proc_lnet_buffers,
	},
	{
		.procname     = "nis",
		.mode         = 0444,
		.proc_handler = &proc_lnet_nis,
	},
	{
		.procname     = "portal_rotor",
		.mode         = 0644,
		.proc_handler = &proc_lnet_portal_rotor,
	},
	{
	}
};

static struct ctl_table top_table[] = {
	{
		.procname = "lnet",
		.mode     = 0555,
		.data     = NULL,
		.maxlen   = 0,
		.child    = lnet_table,
	},
	{
	}
};

void
lnet_proc_init(void)
{
	if (lnet_table_header == NULL)
		lnet_table_header = register_sysctl_table(top_table);
}

void
lnet_proc_fini(void)
{
	if (lnet_table_header != NULL)
		unregister_sysctl_table(lnet_table_header);

	lnet_table_header = NULL;
}

#else

void
lnet_proc_init(void)
{
}

void
lnet_proc_fini(void)
{
}

#endif