From 17b49a67a6a59f0e9f3c22e67ddb602410e8e182 Mon Sep 17 00:00:00 2001 From: Jack Steiner Date: Wed, 17 Jun 2009 16:28:23 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/misc/sgi-gru/grukservices.c | 33 +++++++++++++++++++++-------- 1 file 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(); -- 2.20.1