From b12ccb74a074afcd1dbf67ac380799aad1873f03 Mon Sep 17 00:00:00 2001
From: Houston Hoffman <hhoffman@codeaurora.org>
Date: Wed, 1 Mar 2017 20:02:28 -0800
Subject: [PATCH] qcacmn: Support oom recovery for rx ce's

In oom condition, when an rx ce is oom, the ce would
deadlock as the hw couldn't copy any messages (due to the oom)
and the sw wouldn't initiate a pipe refill without a new message.

When this happens submit a work to a workqueue to try and kickstart
the cycle by allocating an nbuf and posting it to the ce.

Change-Id: I047818145dbe230fefc447b6b034705f9b87ca70
CRs-Fixed: 2015778
---
 hif/src/ce/ce_internal.h |  1 +
 hif/src/ce/ce_main.c     | 47 +++++++++++++++++++++++++++++++++++++---
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/hif/src/ce/ce_internal.h b/hif/src/ce/ce_internal.h
index 7569d10a9c..ff649a62a1 100644
--- a/hif/src/ce/ce_internal.h
+++ b/hif/src/ce/ce_internal.h
@@ -112,6 +112,7 @@ struct CE_state {
 	fastpath_msg_handler fastpath_handler;
 	void *context;
 #endif /* WLAN_FEATURE_FASTPATH */
+	qdf_work_t oom_allocation_work;
 
 	ce_send_cb send_cb;
 	void *send_context;
diff --git a/hif/src/ce/ce_main.c b/hif/src/ce/ce_main.c
index dd3b38c014..48417a55e4 100644
--- a/hif/src/ce/ce_main.c
+++ b/hif/src/ce/ce_main.c
@@ -839,6 +839,26 @@ int hif_ce_bus_late_resume(struct hif_softc *scn)
 	return 0;
 }
 
+/**
+ * ce_oom_recovery() - try to recover rx ce from oom condition
+ * @context: CE_state of the CE with oom rx ring
+ *
+ * the executing work Will continue to be rescheduled untill
+ * at least 1 descriptor is successfully posted to the rx ring.
+ *
+ * return: none
+ */
+static void ce_oom_recovery(void *context)
+{
+	struct CE_state *ce_state = context;
+	struct hif_softc *scn = ce_state->scn;
+	struct HIF_CE_state *ce_softc = HIF_GET_CE_STATE(scn);
+	struct HIF_CE_pipe_info *pipe_info =
+		&ce_softc->pipe_info[ce_state->id];
+
+	hif_post_recv_buffers_for_pipe(pipe_info);
+}
+
 /*
  * Initialize a Copy Engine based on caller-supplied attributes.
  * This may be called once to initialize both source and destination
@@ -1062,6 +1082,9 @@ struct CE_handle *ce_init(struct hif_softc *scn,
 			goto error_target_access;
 	}
 
+	qdf_create_work(scn->qdf_dev, &CE_state->oom_allocation_work,
+			ce_oom_recovery, CE_state);
+
 	/* update the htt_data attribute */
 	ce_mark_datapath(CE_state);
 
@@ -1744,11 +1767,16 @@ static void hif_post_recv_buffers_failure(struct HIF_CE_pipe_info *pipe_info,
 	 *	there is no trigger to refill the ce and we will
 	 *	eventually crash
 	 */
-	if (bufs_needed_tmp == CE_state->dest_ring->nentries - 1)
+	if (bufs_needed_tmp == CE_state->dest_ring->nentries - 1) {
+
 		QDF_ASSERT(0);
+		qdf_sched_work(scn->qdf_dev, &CE_state->oom_allocation_work);
+	}
 }
 
 
+
+
 static int hif_post_recv_buffers_for_pipe(struct HIF_CE_pipe_info *pipe_info)
 {
 	struct CE_handle *ce_hdl;
@@ -1788,8 +1816,7 @@ static int hif_post_recv_buffers_for_pipe(struct HIF_CE_pipe_info *pipe_info)
 		 * CE_data = dma_map_single(dev, data, buf_sz, );
 		 * DMA_FROM_DEVICE);
 		 */
-		ret =
-			qdf_nbuf_map_single(scn->qdf_dev, nbuf,
+		ret = qdf_nbuf_map_single(scn->qdf_dev, nbuf,
 					    QDF_DMA_FROM_DEVICE);
 
 		if (unlikely(ret != QDF_STATUS_SUCCESS)) {
@@ -2026,6 +2053,19 @@ void hif_flush_surprise_remove(struct hif_opaque_softc *hif_ctx)
 	hif_buffer_cleanup(hif_state);
 }
 
+static void hif_destroy_oom_work(struct hif_softc *scn)
+{
+	struct CE_state *ce_state;
+	int ce_id;
+
+	for (ce_id = 0; ce_id < scn->ce_count; ce_id++) {
+		ce_state = scn->ce_id_to_state[ce_id];
+		if (ce_state)
+			qdf_destroy_work(scn->qdf_dev,
+					 &ce_state->oom_allocation_work);
+	}
+}
+
 void hif_ce_stop(struct hif_softc *scn)
 {
 	struct HIF_CE_state *hif_state = HIF_GET_CE_STATE(scn);
@@ -2036,6 +2076,7 @@ void hif_ce_stop(struct hif_softc *scn)
 	 * bottom half contexts will not be re-entered
 	 */
 	hif_nointrs(scn);
+	hif_destroy_oom_work(scn);
 	scn->hif_init_done = false;
 
 	/*