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From: Alexandre Bounine on 8 Mar 2010 14:10

From: Alexandre Bounine <alexandre.bounine(a)idt.com>

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: Alexandre Bounine <alexandre.bounine(a)idt.com>
Tested-by: Thomas Moll <thomas.moll(a)sysgo.com>
---

rio-scan.c | 163 +++++++++++++++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 143 insertions(+), 20 deletions(-)

diff -x '*.pj' -X dontdiff_2.6.32-rc5 -pNur w33a/drivers/rapidio/rio-scan.c w33b/drivers/rapidio/rio-scan.c
--- w33a/drivers/rapidio/rio-scan.c 2010-03-01 11:16:46.197496000 -0500
+++ w33b/drivers/rapidio/rio-scan.c 2010-03-04 10:03:35.860207000 -0500
@@ -457,12 +457,87 @@ rio_sport_is_active(struct rio_mport *po
}

/**
+ * 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
* @rswitch: Switch device
* @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 *po
* %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 ri
* @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 ri
*/
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(struc
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(struc
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 +790,7 @@ static int __devinit rio_enum_peer(struc
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 +881,21 @@ rio_disc_peer(struct rio_net *net, struc
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;
@@ -886,7 +993,9 @@ static void rio_update_route_tables(stru
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;
}
}
@@ -960,15 +1069,22 @@ static void rio_build_route_tables(void)
u8 sport;

list_for_each_entry(rdev, &rio_devices, global_list)
- if (rio_is_switch(rdev))
- 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)
- continue;
- rdev->rswitch->route_table[i] = sport;
+ 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) < 0)
+ continue;
+ rdev->rswitch->route_table[i] = sport;
+ }
+
+ rio_unlock_device(rdev->net->hport,
+ rdev->rswitch->destid,
+ rdev->rswitch->hopcount);
}
}

@@ -1027,6 +1143,13 @@ int __devinit rio_disc_mport(struct rio_
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

---

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Prev: [PATCH] Security: key: keyring: fix code style issues
Next: tracing: adding ftrace events for graph tracer