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Commit 818a04a0 authored by Alexandre Bounine's avatar Alexandre Bounine Committed by Linus Torvalds
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rapidio: add switch locking during discovery 



Add switch access locking during RapidIO discovery.  Access lock is
required when reading switch routing table contents due to indexed
mechanism of RT addressing.

Signed-off-by: default avatarAlexandre Bounine <alexandre.bounine@idt.com>
Tested-by: default avatarThomas Moll <thomas.moll@sysgo.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 07590ff0

drivers/rapidio/rio-scan.c

+144 −20
Original line number Diff line number Diff line
@@ -456,6 +456,80 @@ rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport) 
	return (result & PORT_N_ERR_STS_PORT_OK);

}



/**

 * rio_lock_device - Acquires host device lock for specified device

 * @port: Master port to send transaction

 * @destid: Destination ID for device/switch

 * @hopcount: Hopcount to reach switch

 * @wait_ms: Max wait time in msec (0 = no timeout)

 *

 * Attepts to acquire host device lock for specified device

 * Returns 0 if device lock acquired or EINVAL if timeout expires.

 */

static int

rio_lock_device(struct rio_mport *port, u16 destid, u8 hopcount, int wait_ms)

{

	u32 result;

	int tcnt = 0;



	/* Attempt to acquire device lock */

	rio_mport_write_config_32(port, destid, hopcount,

				  RIO_HOST_DID_LOCK_CSR, port->host_deviceid);

	rio_mport_read_config_32(port, destid, hopcount,

				 RIO_HOST_DID_LOCK_CSR, &result);



	while (result != port->host_deviceid) {

		if (wait_ms != 0 && tcnt == wait_ms) {

			pr_debug("RIO: timeout when locking device %x:%x\n",

				destid, hopcount);

			return -EINVAL;

		}



		/* Delay a bit */

		mdelay(1);

		tcnt++;

		/* Try to acquire device lock again */

		rio_mport_write_config_32(port, destid,

			hopcount,

			RIO_HOST_DID_LOCK_CSR,

			port->host_deviceid);

		rio_mport_read_config_32(port, destid,

			hopcount,

			RIO_HOST_DID_LOCK_CSR, &result);

	}



	return 0;

}



/**

 * rio_unlock_device - Releases host device lock for specified device

 * @port: Master port to send transaction

 * @destid: Destination ID for device/switch

 * @hopcount: Hopcount to reach switch

 *

 * Returns 0 if device lock released or EINVAL if fails.

 */

static int

rio_unlock_device(struct rio_mport *port, u16 destid, u8 hopcount)

{

	u32 result;



	/* Release device lock */

	rio_mport_write_config_32(port, destid,

				  hopcount,

				  RIO_HOST_DID_LOCK_CSR,

				  port->host_deviceid);

	rio_mport_read_config_32(port, destid, hopcount,

		RIO_HOST_DID_LOCK_CSR, &result);

	if ((result & 0xffff) != 0xffff) {

		pr_debug("RIO: badness when releasing device lock %x:%x\n",

			 destid, hopcount);

		return -EINVAL;

	}



	return 0;

}



/**

 * rio_route_add_entry- Add a route entry to a switch routing table

 * @mport: Master port to send transaction
@@ -463,6 +537,7 @@ rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport) 
 * @table: Routing table ID

 * @route_destid: Destination ID to be routed

 * @route_port: Port number to be routed

 * @lock: lock switch device flag

 *

 * Calls the switch specific add_entry() method to add a route entry

 * on a switch. The route table can be specified using the @table
@@ -471,12 +546,26 @@ rio_sport_is_active(struct rio_mport *port, u16 destid, u8 hopcount, int sport) 
 * %RIO_GLOBAL_TABLE in @table. Returns %0 on success or %-EINVAL

 * on failure.

 */

static int rio_route_add_entry(struct rio_mport *mport, struct rio_switch *rswitch,

			       u16 table, u16 route_destid, u8 route_port)

static int

rio_route_add_entry(struct rio_mport *mport, struct rio_switch *rswitch,

		    u16 table, u16 route_destid, u8 route_port, int lock)

{

	return rswitch->add_entry(mport, rswitch->destid,

	int rc;



	if (lock) {

		rc = rio_lock_device(mport, rswitch->destid,

				     rswitch->hopcount, 1000);

		if (rc)

			return rc;

	}



	rc = rswitch->add_entry(mport, rswitch->destid,

					rswitch->hopcount, table,

					route_destid, route_port);

	if (lock)

		rio_unlock_device(mport, rswitch->destid, rswitch->hopcount);



	return rc;

}



/**
@@ -486,6 +575,7 @@ static int rio_route_add_entry(struct rio_mport *mport, struct rio_switch *rswit 
 * @table: Routing table ID

 * @route_destid: Destination ID to be routed

 * @route_port: Pointer to read port number into

 * @lock: lock switch device flag

 *

 * Calls the switch specific get_entry() method to read a route entry

 * in a switch. The route table can be specified using the @table
@@ -496,11 +586,24 @@ static int rio_route_add_entry(struct rio_mport *mport, struct rio_switch *rswit 
 */

static int

rio_route_get_entry(struct rio_mport *mport, struct rio_switch *rswitch, u16 table,

		    u16 route_destid, u8 * route_port)

		    u16 route_destid, u8 *route_port, int lock)

{

	return rswitch->get_entry(mport, rswitch->destid,

	int rc;



	if (lock) {

		rc = rio_lock_device(mport, rswitch->destid,

				     rswitch->hopcount, 1000);

		if (rc)

			return rc;

	}



	rc = rswitch->get_entry(mport, rswitch->destid,

					rswitch->hopcount, table,

					route_destid, route_port);

	if (lock)

		rio_unlock_device(mport, rswitch->destid, rswitch->hopcount);



	return rc;

}



/**
@@ -640,14 +743,14 @@ static int __devinit rio_enum_peer(struct rio_net *net, struct rio_mport *port, 
		sw_inport = rio_get_swpinfo_inport(port,

				RIO_ANY_DESTID(port->sys_size), hopcount);

		rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,

				    port->host_deviceid, sw_inport);

				    port->host_deviceid, sw_inport, 0);

		rdev->rswitch->route_table[port->host_deviceid] = sw_inport;



		for (destid = 0; destid < next_destid; destid++) {

			if (destid == port->host_deviceid)

				continue;

			rio_route_add_entry(port, rdev->rswitch, RIO_GLOBAL_TABLE,

					    destid, sw_inport);

					    destid, sw_inport, 0);

			rdev->rswitch->route_table[destid] = sw_inport;

		}
@@ -673,7 +776,7 @@ static int __devinit rio_enum_peer(struct rio_net *net, struct rio_mport *port, 
				rio_route_add_entry(port, rdev->rswitch,

						RIO_GLOBAL_TABLE,

						RIO_ANY_DESTID(port->sys_size),

						port_num);

						port_num, 0);



				if (rio_enum_peer(net, port, hopcount + 1) < 0)

					return -1;
@@ -687,7 +790,8 @@ static int __devinit rio_enum_peer(struct rio_net *net, struct rio_mport *port, 
						rio_route_add_entry(port, rdev->rswitch,

								    RIO_GLOBAL_TABLE,

								    destid,

								    port_num);

								    port_num,

								    0);

						rdev->rswitch->

						    route_table[destid] =

						    port_num;
@@ -778,17 +882,21 @@ rio_disc_peer(struct rio_net *net, struct rio_mport *port, u16 destid, 
				pr_debug(

				    "RIO: scanning device on port %d\n",

				    port_num);



				rio_lock_device(port, destid, hopcount, 1000);



				for (ndestid = 0;

				     ndestid < RIO_ANY_DESTID(port->sys_size);

				     ndestid++) {

					rio_route_get_entry(port, rdev->rswitch,

							    RIO_GLOBAL_TABLE,

							    ndestid,

							    &route_port);

							    &route_port, 0);

					if (route_port == port_num)

						break;

				}



				rio_unlock_device(port, destid, hopcount);

				if (rio_disc_peer

				    (net, port, ndestid, hopcount + 1) < 0)

					return -1;
@@ -889,7 +997,9 @@ static void rio_update_route_tables(struct rio_mport *port) 
						rswitch->destid, rswitch->hopcount);



				if (rswitch->add_entry)	{

					rio_route_add_entry(port, rswitch, RIO_GLOBAL_TABLE, destid, sport);

					rio_route_add_entry(port, rswitch,

						RIO_GLOBAL_TABLE, destid,

						sport, 0);

					rswitch->route_table[destid] = sport;

				}

			}
@@ -963,16 +1073,23 @@ static void rio_build_route_tables(void) 
	u8 sport;



	list_for_each_entry(rdev, &rio_devices, global_list)

	    if (rio_is_switch(rdev))

		if (rio_is_switch(rdev)) {

			rio_lock_device(rdev->net->hport, rdev->rswitch->destid,

					rdev->rswitch->hopcount, 1000);

			for (i = 0;

			     i < RIO_MAX_ROUTE_ENTRIES(rdev->net->hport->sys_size);

			     i++) {

				if (rio_route_get_entry

			    (rdev->net->hport, rdev->rswitch, RIO_GLOBAL_TABLE,

			     i, &sport) < 0)

				    (rdev->net->hport, rdev->rswitch,

				     RIO_GLOBAL_TABLE, i, &sport, 0) < 0)

					continue;

				rdev->rswitch->route_table[i] = sport;

			}



			rio_unlock_device(rdev->net->hport,

					  rdev->rswitch->destid,

					  rdev->rswitch->hopcount);

		}

}



/**
@@ -1030,6 +1147,13 @@ int __devinit rio_disc_mport(struct rio_mport *mport) 
		del_timer_sync(&rio_enum_timer);



		pr_debug("done\n");



		/* Read DestID assigned by enumerator */

		rio_local_read_config_32(mport, RIO_DID_CSR,

					 &mport->host_deviceid);

		mport->host_deviceid = RIO_GET_DID(mport->sys_size,

						   mport->host_deviceid);



		if (rio_disc_peer(net, mport, RIO_ANY_DESTID(mport->sys_size),

					0) < 0) {

			printk(KERN_INFO