Gitweb: http://git.kernel.org/linus/17b49a67a6a59f0e9f3c22e67ddb602410e8e182
Commit: 17b49a67a6a59f0e9f3c22e67ddb602410e8e182
Parent: 3eac2e95d7bb92222e185e445eca1fe3f695050f
Author: Jack Steiner <steiner@sgi.com>
AuthorDate: Wed Jun 17 16:28:23 2009 -0700
Committer: Linus Torvalds <torvalds@linux-foundation.org>
CommitDate: Thu Jun 18 13:04:00 2009 -0700
gru: fix handling of mesq failures
Fix endcase in handling GRU message queue failures due to NACKs of PUT
requests. Must ensure that the "present" bits are cleared before
resending the message.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/misc/sgi-gru/grukservices.c | 33 ++++++++++++++++++++++++---------
1 files changed, 24 insertions(+), 9 deletions(-)
diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c
index 50b4dd8..a0f9810 100644
--- a/drivers/misc/sgi-gru/grukservices.c
+++ b/drivers/misc/sgi-gru/grukservices.c
@@ -503,6 +503,29 @@ static void send_message_queue_interrupt(struct gru_message_queue_desc *mqd)
mqd->interrupt_vector);
}
+/*
+ * Handle a PUT failure. Note: if message was a 2-line message, one of the
+ * lines might have successfully have been written. Before sending the
+ * message, "present" must be cleared in BOTH lines to prevent the receiver
+ * from prematurely seeing the full message.
+ */
+static int send_message_put_nacked(void *cb, struct gru_message_queue_desc *mqd,
+ void *mesg, int lines)
+{
+ unsigned long m;
+
+ m = mqd->mq_gpa + (gru_get_amo_value_head(cb) << 6);
+ if (lines == 2) {
+ gru_vset(cb, m, 0, XTYPE_CL, lines, 1, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ return MQE_UNEXPECTED_CB_ERR;
+ }
+ gru_vstore(cb, m, gru_get_tri(mesg), XTYPE_CL, lines, 1, IMA);
+ if (gru_wait(cb) != CBS_IDLE)
+ return MQE_UNEXPECTED_CB_ERR;
+ send_message_queue_interrupt(mqd);
+ return MQE_OK;
+}
/*
* Handle a gru_mesq failure. Some of these failures are software recoverable
@@ -512,7 +535,6 @@ static int send_message_failure(void *cb, struct gru_message_queue_desc *mqd,
void *mesg, int lines)
{
int substatus, ret = 0;
- unsigned long m;
substatus = gru_get_cb_message_queue_substatus(cb);
switch (substatus) {
@@ -534,14 +556,7 @@ static int send_message_failure(void *cb, struct gru_message_queue_desc *mqd,
break;
case CBSS_PUT_NACKED:
STAT(mesq_send_put_nacked);
- m = mqd->mq_gpa + (gru_get_amo_value_head(cb) << 6);
- gru_vstore(cb, m, gru_get_tri(mesg), XTYPE_CL, lines, 1, IMA);
- if (gru_wait(cb) == CBS_IDLE) {
- ret = MQE_OK;
- send_message_queue_interrupt(mqd);
- } else {
- ret = MQE_UNEXPECTED_CB_ERR;
- }
+ ret = send_message_put_nacked(cb, mqd, mesg, lines);
break;
default:
BUG();
--
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
