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Commit 6429cd49 authored by Alexandre Bounine's avatar Alexandre Bounine Committed by Linus Torvalds
Browse files

rapidio: add handling of orphan port-write message 



Add check for access to port-write (PW) message source device before
processing the PW message.  If source RIO device is not available (power
down or RIO link failure) trace back to a last available switch/port on
the PW message route and service failure at that point.

Signed-off-by: default avatarAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Thomas 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>
Cc: Micha Nelissen <micha@neli.hopto.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ac38d723

drivers/rapidio/rio.c

+108 −5
Original line number Diff line number Diff line
@@ -494,6 +494,92 @@ int rio_set_port_lockout(struct rio_dev *rdev, u32 pnum, int lock) 
	return 0;

}



/**

 * rio_chk_dev_route - Validate route to the specified device.

 * @rdev:  RIO device failed to respond

 * @nrdev: Last active device on the route to rdev

 * @npnum: nrdev's port number on the route to rdev

 *

 * Follows a route to the specified RIO device to determine the last available

 * device (and corresponding RIO port) on the route.

 */

static int

rio_chk_dev_route(struct rio_dev *rdev, struct rio_dev **nrdev, int *npnum)

{

	u32 result;

	int p_port, rc = -EIO;

	struct rio_dev *prev = NULL;



	/* Find switch with failed RIO link */

	while (rdev->prev && (rdev->prev->pef & RIO_PEF_SWITCH)) {

		if (!rio_read_config_32(rdev->prev, RIO_DEV_ID_CAR, &result)) {

			prev = rdev->prev;

			break;

		}

		rdev = rdev->prev;

	}



	if (prev == NULL)

		goto err_out;



	/* Find port with failed RIO link */

	for (p_port = 0;

	     p_port < RIO_GET_TOTAL_PORTS(prev->swpinfo); p_port++)

		if (prev->rswitch->nextdev[p_port] == rdev)

			break;



	if (p_port < RIO_GET_TOTAL_PORTS(prev->swpinfo)) {

		pr_debug("RIO: link failed on [%s]-P%d\n",

			 rio_name(prev), p_port);

		*nrdev = prev;

		*npnum = p_port;

		rc = 0;

	} else

		pr_debug("RIO: failed to trace route to %s\n", rio_name(prev));

err_out:

	return rc;

}



/**

 * rio_mport_chk_dev_access - Validate access to the specified device.

 * @mport: Master port to send transactions

 * @destid: Device destination ID in network

 * @hopcount: Number of hops into the network

 */

static int

rio_mport_chk_dev_access(struct rio_mport *mport, u16 destid, u8 hopcount)

{

	int i = 0;

	u32 tmp;



	while (rio_mport_read_config_32(mport, destid, hopcount,

					RIO_DEV_ID_CAR, &tmp)) {

		i++;

		if (i == RIO_MAX_CHK_RETRY)

			return -EIO;

		mdelay(1);

	}



	return 0;

}



/**

 * rio_chk_dev_access - Validate access to the specified device.

 * @rdev: Pointer to RIO device control structure

 */

static int rio_chk_dev_access(struct rio_dev *rdev)

{

	u8 hopcount = 0xff;

	u16 destid = rdev->destid;



	if (rdev->rswitch) {

		destid = rdev->rswitch->destid;

		hopcount = rdev->rswitch->hopcount;

	}



	return rio_mport_chk_dev_access(rdev->net->hport, destid, hopcount);

}



/**

 * rio_get_input_status - Sends a Link-Request/Input-Status control symbol and

 *                        returns link-response (if requested).
@@ -654,8 +740,8 @@ int rio_inb_pwrite_handler(union rio_pw_msg *pw_msg) 


	rdev = rio_get_comptag(pw_msg->em.comptag, NULL);

	if (rdev == NULL) {

		/* Someting bad here (probably enumeration error) */

		pr_err("RIO: %s No matching device for CTag 0x%08x\n",

		/* Device removed or enumeration error */

		pr_debug("RIO: %s No matching device for CTag 0x%08x\n",

			__func__, pw_msg->em.comptag);

		return -EIO;

	}
@@ -686,6 +772,26 @@ int rio_inb_pwrite_handler(union rio_pw_msg *pw_msg) 
			return 0;

	}



	portnum = pw_msg->em.is_port & 0xFF;



	/* Check if device and route to it are functional:

	 * Sometimes devices may send PW message(s) just before being

	 * powered down (or link being lost).

	 */

	if (rio_chk_dev_access(rdev)) {

		pr_debug("RIO: device access failed - get link partner\n");

		/* Scan route to the device and identify failed link.

		 * This will replace device and port reported in PW message.

		 * PW message should not be used after this point.

		 */

		if (rio_chk_dev_route(rdev, &rdev, &portnum)) {

			pr_err("RIO: Route trace for %s failed\n",

				rio_name(rdev));

			return -EIO;

		}

		pw_msg = NULL;

	}



	/* For End-point devices processing stops here */

	if (!(rdev->pef & RIO_PEF_SWITCH))

		return 0;
@@ -703,9 +809,6 @@ int rio_inb_pwrite_handler(union rio_pw_msg *pw_msg) 
	/*

	 * Process the port-write notification from switch

	 */



	portnum = pw_msg->em.is_port & 0xFF;



	if (rdev->rswitch->em_handle)

		rdev->rswitch->em_handle(rdev, portnum);

drivers/rapidio/rio.h

+2 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 
#include <linux/list.h>

#include <linux/rio.h>



#define RIO_MAX_CHK_RETRY	3



/* Functions internal to the RIO core code */



extern u32 rio_mport_get_feature(struct rio_mport *mport, int local, u16 destid,