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authorStefan Richter <stefanr@s5r6.in-berlin.de>2008-08-27 01:18:32 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2009-02-24 14:51:26 +0100
commit29f8ea8ab09bad0c3c0d67964559d27643e97903 (patch)
tree841538d670636493ccb4bd240739e934dd09fda1 /drivers/ieee1394
parent612262a53352af839a14b3395975a3440c95080a (diff)
downloadop-kernel-dev-29f8ea8ab09bad0c3c0d67964559d27643e97903.zip
op-kernel-dev-29f8ea8ab09bad0c3c0d67964559d27643e97903.tar.gz
ieee1394: use correct barrier types between accesses of nodeid and generation
A compiler barrier (explicit on the read side, implicit on the write side) is not quite enough for what has to be accomplished here. Use hardware memory barriers on systems which need them. (Of course a full fix of generation handling would require much more than this. The ieee1394 core's bus generation counter had to be tied to the controller's bus generation counter; cf. Kristian's stack. It's just that I have other current business with the code around these barrier()s, so why not do at least this small fix.) Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/ieee1394')
-rw-r--r--drivers/ieee1394/nodemgr.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c
index 906c5a9..f47b6f6 100644
--- a/drivers/ieee1394/nodemgr.c
+++ b/drivers/ieee1394/nodemgr.c
@@ -1265,7 +1265,8 @@ static void nodemgr_update_node(struct node_entry *ne, struct csr1212_csr *csr,
csr1212_destroy_csr(csr);
}
- /* Mark the node current */
+ /* Finally, mark the node current */
+ smp_wmb();
ne->generation = generation;
if (ne->in_limbo) {
@@ -1798,7 +1799,7 @@ void hpsb_node_fill_packet(struct node_entry *ne, struct hpsb_packet *packet)
{
packet->host = ne->host;
packet->generation = ne->generation;
- barrier();
+ smp_rmb();
packet->node_id = ne->nodeid;
}
@@ -1807,7 +1808,7 @@ int hpsb_node_write(struct node_entry *ne, u64 addr,
{
unsigned int generation = ne->generation;
- barrier();
+ smp_rmb();
return hpsb_write(ne->host, ne->nodeid, generation,
addr, buffer, length);
}
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