From 29f8ea8ab09bad0c3c0d67964559d27643e97903 Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Wed, 27 Aug 2008 01:18:32 +0200 Subject: 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 --- drivers/ieee1394/nodemgr.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/ieee1394') diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c index 906c5a98d814..f47b6f69d2a9 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); } -- cgit v1.2.3-58-ga151