From: Alexandre Bounine <[email protected]>
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 <[email protected]>
Tested-by: Thomas Moll <[email protected]>
---
rio-scan.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 79 insertions(+), 9 deletions(-)
diff -x '*.pj' -X dontdiff_2.6.32-rc5 -pNur w33r7a/drivers/rapidio/rio-scan.c w33r7b/drivers/rapidio/rio-scan.c
--- w33r7a/drivers/rapidio/rio-scan.c 2010-02-09 15:11:09.141972000 -0500
+++ w33r7b/drivers/rapidio/rio-scan.c 2010-02-10 16:13:56.382802000 -0500
@@ -750,6 +750,7 @@ rio_disc_peer(struct rio_net *net, struc
int num_ports;
struct rio_dev *rdev;
u16 ndestid;
+ u32 result;
/* Setup new RIO device */
if ((rdev = rio_setup_device(net, port, destid, hopcount, 0))) {
@@ -778,6 +779,27 @@ rio_disc_peer(struct rio_net *net, struc
pr_debug(
"RIO: scanning device on port %d\n",
port_num);
+
+ /* 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) {
+ /* Delay a bit */
+ mdelay(1);
+ /* 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);
+ }
+
for (ndestid = 0;
ndestid < RIO_ANY_DESTID(port->sys_size);
ndestid++) {
@@ -789,6 +811,19 @@ rio_disc_peer(struct rio_net *net, struc
break;
}
+ /* 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_info("RIO: badness when releasing " \
+ "host lock on %s\n",
+ rio_name(rdev));
+ }
+
if (rio_disc_peer
(net, port, ndestid, hopcount + 1) < 0)
return -1;
@@ -958,17 +993,45 @@ static void rio_build_route_tables(void)
struct rio_dev *rdev;
int i;
u8 sport;
+ u32 result;
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)) {
+ /* Attempt to acquire device lock */
+ rio_write_config_32(rdev, RIO_HOST_DID_LOCK_CSR,
+ rdev->net->hport->host_deviceid);
+ rio_read_config_32(rdev,
+ RIO_HOST_DID_LOCK_CSR, &result);
+ while (result != rdev->net->hport->host_deviceid) {
+ /* Delay a bit */
+ mdelay(1);
+ /* Attempt to acquire device lock again */
+ rio_write_config_32(rdev, RIO_HOST_DID_LOCK_CSR,
+ rdev->net->hport->host_deviceid);
+ rio_read_config_32(rdev,
+ RIO_HOST_DID_LOCK_CSR, &result);
+ }
+
+ 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;
+ }
+
+ /* Release device lock */
+ rio_write_config_32(rdev, RIO_HOST_DID_LOCK_CSR,
+ rdev->net->hport->host_deviceid);
+ rio_read_config_32(rdev,
+ RIO_HOST_DID_LOCK_CSR, &result);
+ if ((result & 0xffff) != 0xffff) {
+ pr_info("RIO: badness when releasing " \
+ "host lock on %s\n", rio_name(rdev));
+ }
+
}
}
@@ -1027,6 +1090,13 @@ 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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Micha Nelissen wrote:
>
> Alexandre Bounine wrote:
> > + /* 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) {
>
> It's better to abstract the locking of a device into a new function,
> rio_lock_device / rio_unlock_device.
>
> Then you can use those in rio_get_route_entry and rio_add_route_entry.
Agree. Plus, adding a "lock" parameter to
rio_get_route_entry/rio_add_route_entry to avoid excessive locking
requests when scanning entire table. I will do it in next version or as
additional patch: I have to address locking anyway for future changes.
>
> > @@ -1027,6 +1090,13 @@ int __devinit rio_disc_mport(struct rio_
> > +
> > + /* 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);
> > +
>
> This fixes something else, should be a separate patch.
This sets an ID used for locking during discovery. On a startup only
enumerator's ID is set to the specified value. All discovering agents
have this ID set to -1. After enumeration is completed it is safe to
initialize host_deviceid for agents as well.
Alex.