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gru: fix handling of mesq failures

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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>
This commit is contained in:
Jack Steiner 2009-06-17 16:28:23 -07:00 committed by Linus Torvalds
parent 3eac2e95d7
commit 17b49a67a6
1 changed files with 24 additions and 9 deletions
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33
drivers/misc/sgi-gru/grukservices.c
View file

@ -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();