The patch titled
gru: fix handling of mesq failures
has been added to the -mm tree. Its filename is
gru-fix-handling-of-mesq-failures.patch
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------------------------------------------------------
Subject: gru: fix handling of mesq failures
From: Jack Steiner <steiner@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/misc/sgi-gru/grukservices.c | 33 ++++++++++++++++++--------
1 file changed, 24 insertions(+), 9 deletions(-)
diff -puN drivers/misc/sgi-gru/grukservices.c~gru-fix-handling-of-mesq-failures drivers/misc/sgi-gru/grukservices.c
--- a/drivers/misc/sgi-gru/grukservices.c~gru-fix-handling-of-mesq-failures
+++ a/drivers/misc/sgi-gru/grukservices.c
@@ -503,6 +503,29 @@ static void send_message_queue_interrupt
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
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
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();
_
Patches currently in -mm which might be from steiner@xxxxxxx are
gru-bug-fixes-for-gru-exception-handling.patch
gru-dump-chiplet-state.patch
gru-dynamic-allocation-of-kernel-contexts.patch
gru-change-context-load-and-unload.patch
gru-support-cch_allocate-for-kernel-threads.patch
gru-change-resource-assignment-for-kernel-threads.patch
gru-support-contexts-with-zero-dsrs-or-cbrs.patch
gru-fix-handling-of-mesq-failures.patch
gru-check-context-state-on-reload.patch
gru-support-instruction-completion-interrupts.patch
gru-support-for-asynchronous-gru-instructions.patch
gru-update-gru-kernel-self-tests.patch
gru-update-to-rev-09-of-gru-spec.patch
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