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authorJack Steiner <steiner@sgi.com>2009-06-17 16:28:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-18 13:04:00 -0700
commit17b49a67a6a59f0e9f3c22e67ddb602410e8e182 (patch)
treec12156560f6ed549d008ce4d630d791be11f4999 /drivers/misc
parent3eac2e95d7bb92222e185e445eca1fe3f695050f (diff)
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>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/sgi-gru/grukservices.c33
1 files changed, 24 insertions, 9 deletions
diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c
index 50b4dd8b0c9f..a0f981022a6c 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();