[RFC PATCH v2 4/5] arm_mpam: resctrl: Add resctrl_arch_cntr_read() & resctrl_arch_reset_cntr()

[Ben Horgan]

From: James Morse <james.morse@xxxxxxx>

When used in 'mbm_event' mode, ABMC emulation, resctrl uses arch hooks to
read and reset the memory bandwidth utilization (MBWU) counters.

Add these.

Reviewed-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Ben Horgan <ben.horgan@xxxxxxx>
---
Changes since rfc v1:
Move __reset_mon() and reset_mon_cdp_safe() helpers here
support mbwu in __read_mon()
Mention mbm_event mode in commit message
---
 drivers/resctrl/mpam_resctrl.c | 99 +++++++++++++++++++++++++++++-----
 1 file changed, 86 insertions(+), 13 deletions(-)

diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 4f49483f6445..9f6f0091f356 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -121,19 +121,6 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_l3_mon_domain *d
 {
 }
 
-void resctrl_arch_reset_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
-			     u32 closid, u32 rmid, int cntr_id,
-			     enum resctrl_event_id eventid)
-{
-}
-
-int resctrl_arch_cntr_read(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
-			   u32 unused, u32 rmid, int cntr_id,
-			   enum resctrl_event_id eventid, u64 *val)
-{
-	return -EOPNOTSUPP;
-}
-
 bool resctrl_arch_mbm_cntr_assign_enabled(struct rdt_resource *r)
 {
 	return (r == &mpam_resctrl_controls[RDT_RESOURCE_L3].resctrl_res);
@@ -459,6 +446,14 @@ static int __read_mon(struct mpam_resctrl_mon *mon, struct mpam_component *mon_c
 	/* Shift closid to account for CDP */
 	closid = resctrl_get_config_index(closid, cdp_type);
 
+	if (mon_idx == USE_PRE_ALLOCATED) {
+		int mbwu_idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+
+		mon_idx = mon->mbwu_idx_to_mon[mbwu_idx];
+		if (mon_idx == -1)
+			return -ENOENT;
+	}
+
 	if (irqs_disabled()) {
 		/* Check if we can access this domain without an IPI */
 		return -EIO;
@@ -531,6 +526,84 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain_hdr *hdr,
 				 closid, rmid, val);
 }
 
+/* MBWU counters when in ABMC mode */
+int resctrl_arch_cntr_read(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+			   u32 closid, u32 rmid, int mon_idx,
+			   enum resctrl_event_id eventid, u64 *val)
+{
+	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
+	struct mpam_resctrl_dom *l3_dom;
+	struct mpam_component *mon_comp;
+
+	if (!mpam_is_enabled())
+		return -EINVAL;
+
+	if (eventid == QOS_L3_OCCUP_EVENT_ID || !mon->class)
+		return -EINVAL;
+
+	l3_dom = container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom);
+	mon_comp = l3_dom->mon_comp[eventid];
+
+	return read_mon_cdp_safe(mon, mon_comp, mpam_feat_msmon_mbwu, mon_idx,
+				 closid, rmid, val);
+}
+
+static void __reset_mon(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+			int mon_idx,
+			enum resctrl_conf_type cdp_type, u32 closid, u32 rmid)
+{
+	struct mon_cfg cfg = { };
+
+	if (!mpam_is_enabled())
+		return;
+
+	/* Shift closid to account for CDP */
+	closid = resctrl_get_config_index(closid, cdp_type);
+
+	if (mon_idx == USE_PRE_ALLOCATED) {
+		int mbwu_idx = resctrl_arch_rmid_idx_encode(closid, rmid);
+
+		mon_idx = mon->mbwu_idx_to_mon[mbwu_idx];
+	}
+
+	if (mon_idx == -1)
+		return;
+	cfg.mon = mon_idx;
+	mpam_msmon_reset_mbwu(mon_comp, &cfg);
+}
+
+static void reset_mon_cdp_safe(struct mpam_resctrl_mon *mon, struct mpam_component *mon_comp,
+			       int mon_idx, u32 closid, u32 rmid)
+{
+	if (cdp_enabled) {
+		__reset_mon(mon, mon_comp, mon_idx, CDP_CODE, closid, rmid);
+		__reset_mon(mon, mon_comp, mon_idx, CDP_DATA, closid, rmid);
+	} else {
+		__reset_mon(mon, mon_comp, mon_idx, CDP_NONE, closid, rmid);
+	}
+}
+
+/* Reset an assigned counter */
+void resctrl_arch_reset_cntr(struct rdt_resource *r, struct rdt_l3_mon_domain *d,
+			     u32 closid, u32 rmid, int cntr_id,
+			     enum resctrl_event_id eventid)
+{
+	struct mpam_resctrl_mon *mon = &mpam_resctrl_counters[eventid];
+	struct mpam_resctrl_dom *l3_dom;
+	struct mpam_component *mon_comp;
+
+	if (!mpam_is_enabled())
+		return;
+
+	if (eventid == QOS_L3_OCCUP_EVENT_ID || !mon->class)
+		return;
+
+	l3_dom = container_of(d, struct mpam_resctrl_dom, resctrl_mon_dom);
+	mon_comp = l3_dom->mon_comp[eventid];
+
+	reset_mon_cdp_safe(mon, mon_comp, USE_PRE_ALLOCATED, closid, rmid);
+}
+
 /*
  * The rmid realloc threshold should be for the smallest cache exposed to
  * resctrl.
-- 
2.43.0