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rapidio: add handling of orphan port-write message

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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: Alexandre 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexandre Bounine 2010-10-27 15:34:32 -07:00 committed by Linus Torvalds
parent ac38d7232d
commit 6429cd49f4
2 changed files with 110 additions and 5 deletions
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113
drivers/rapidio/rio.c
View file

@ -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);

2
drivers/rapidio/rio.h
View file

@ -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,