[PATCH v3 5/5] interconnect: qcom: icc-rpm: Set bandwidth and clock for bucket values

[Leo Yan <leo.yan@linaro.org>]

This commit uses buckets for support bandwidth and clock rates.  It
introduces a new function qcom_icc_bus_aggregate() to calculate the
aggregate average and peak bandwidths for every bucket, and also it
calculates the maximum aggregate values across all buckets.

The maximum aggregate values are used to calculate the final bandwidth
requests.  And we can set the clock rate per bucket, we use SLEEP bucket
as default bucket if a platform doesn't enable the interconnect path
tags in DT binding; otherwise, we use WAKE bucket to set active clock
and use SLEEP bucket for other clocks.  So far we don't use AMC bucket.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 drivers/interconnect/qcom/icc-rpm.c | 80 ++++++++++++++++++++++++-----
 1 file changed, 67 insertions(+), 13 deletions(-)

diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
index b025fc6b97c9..4b932eb807c7 100644
--- a/drivers/interconnect/qcom/icc-rpm.c
+++ b/drivers/interconnect/qcom/icc-rpm.c
@@ -302,18 +302,62 @@ static int qcom_icc_bw_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
 	return 0;
 }
 
+/**
+ * qcom_icc_bus_aggregate - aggregate bandwidth by traversing all nodes
+ * @provider: generic interconnect provider
+ * @agg_avg: an array for aggregated average bandwidth of buckets
+ * @agg_peak: an array for aggregated peak bandwidth of buckets
+ * @max_agg_avg: pointer to max value of aggregated average bandwidth
+ * @max_agg_peak: pointer to max value of aggregated peak bandwidth
+ */
+static void qcom_icc_bus_aggregate(struct icc_provider *provider,
+				   u64 *agg_avg, u64 *agg_peak,
+				   u64 *max_agg_avg, u64 *max_agg_peak)
+{
+	struct icc_node *node;
+	struct qcom_icc_node *qn;
+	int i;
+
+	/* Initialise aggregate values */
+	for (i = 0; i < QCOM_ICC_NUM_BUCKETS; i++) {
+		agg_avg[i] = 0;
+		agg_peak[i] = 0;
+	}
+
+	*max_agg_avg = 0;
+	*max_agg_peak = 0;
+
+	/*
+	 * Iterate nodes on the interconnect and aggregate bandwidth
+	 * requests for every bucket.
+	 */
+	list_for_each_entry(node, &provider->nodes, node_list) {
+		qn = node->data;
+		for (i = 0; i < QCOM_ICC_NUM_BUCKETS; i++) {
+			agg_avg[i] += qn->sum_avg[i];
+			agg_peak[i] = max_t(u64, agg_peak[i], qn->max_peak[i]);
+		}
+	}
+
+	/* Find maximum values across all buckets */
+	for (i = 0; i < QCOM_ICC_NUM_BUCKETS; i++) {
+		*max_agg_avg = max_t(u64, *max_agg_avg, agg_avg[i]);
+		*max_agg_peak = max_t(u64, *max_agg_peak, agg_peak[i]);
+	}
+}
+
 static int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
 {
 	struct qcom_icc_provider *qp;
 	struct qcom_icc_node *src_qn = NULL, *dst_qn = NULL;
 	struct icc_provider *provider;
-	struct icc_node *n;
 	u64 sum_bw;
 	u64 max_peak_bw;
 	u64 rate;
-	u32 agg_avg = 0;
-	u32 agg_peak = 0;
+	u64 agg_avg[QCOM_ICC_NUM_BUCKETS], agg_peak[QCOM_ICC_NUM_BUCKETS];
+	u64 max_agg_avg, max_agg_peak;
 	int ret, i;
+	int bucket;
 
 	src_qn = src->data;
 	if (dst)
@@ -321,12 +365,11 @@ static int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
 	provider = src->provider;
 	qp = to_qcom_provider(provider);
 
-	list_for_each_entry(n, &provider->nodes, node_list)
-		provider->aggregate(n, 0, n->avg_bw, n->peak_bw,
-				    &agg_avg, &agg_peak);
+	qcom_icc_bus_aggregate(provider, agg_avg, agg_peak, &max_agg_avg,
+			       &max_agg_peak);
 
-	sum_bw = icc_units_to_bps(agg_avg);
-	max_peak_bw = icc_units_to_bps(agg_peak);
+	sum_bw = icc_units_to_bps(max_agg_avg);
+	max_peak_bw = icc_units_to_bps(max_agg_peak);
 
 	ret = __qcom_icc_set(src, src_qn, sum_bw);
 	if (ret)
@@ -337,12 +380,23 @@ static int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
 			return ret;
 	}
 
-	rate = max(sum_bw, max_peak_bw);
-
-	do_div(rate, src_qn->buswidth);
-	rate = min_t(u64, rate, LONG_MAX);
-
 	for (i = 0; i < qp->num_clks; i++) {
+		/*
+		 * Use WAKE bucket for active clock, otherwise, use SLEEP bucket
+		 * for other clocks.  If a platform doesn't set interconnect
+		 * path tags, by default use sleep bucket for all clocks.
+		 *
+		 * Note, AMC bucket is not supported yet.
+		 */
+		if (!strcmp(qp->bus_clks[i].id, "bus_a"))
+			bucket = QCOM_ICC_BUCKET_WAKE;
+		else
+			bucket = QCOM_ICC_BUCKET_SLEEP;
+
+		rate = icc_units_to_bps(max(agg_avg[bucket], agg_peak[bucket]));
+		do_div(rate, src_qn->buswidth);
+		rate = min_t(u64, rate, LONG_MAX);
+
 		if (qp->bus_clk_rate[i] == rate)
 			continue;
 
-- 
2.25.1