[RFC PATCH 10/10] arm_mpam: resctrl: Expose the bandwidth minimum and limit as pseudo resources

[Jinjie Ruan]

Expose MBMIN, MBHDL and MBOPT, re-using the class picked for MBA.

MBMIN carries the bandwidth minimum as a percentage; MBHDL toggles the
MBW_MAX hard-limit bit; MBOPT exposes the raw MBW_MAX fraction without
the percentage scaling.

control_init() describes them as RESCTRL_SCHEMA_RANGE, with the ranges
derived from bwa_wd. update_one() and get_config() carry the values
through the mpam_config fields added earlier.

Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
 drivers/resctrl/mpam_resctrl.c | 73 ++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c
index 008db81e734b..346ee3729ddf 100644
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -1064,8 +1064,14 @@ static void mpam_resctrl_pick_mba(void)
 		res->class = candidate_class;
 
 		/* As with the caches, re-use the class for the pseudo resources */
+		if (mpam_has_feature(mpam_feat_mbw_min, cprops))
+			mpam_resctrl_controls[RDT_RESOURCE_MB_MIN].class = candidate_class;
 		if (mpam_has_feature(mpam_feat_intpri_part, cprops))
 			mpam_resctrl_controls[RDT_RESOURCE_MB_PRI].class = candidate_class;
+		if (mpam_has_feature(mpam_feat_max_limit, cprops))
+			mpam_resctrl_controls[RDT_RESOURCE_MB_HDL].class = candidate_class;
+		if (mba_class_use_mbw_max(cprops))
+			mpam_resctrl_controls[RDT_RESOURCE_MB_OPT].class = candidate_class;
 	}
 }
 
@@ -1317,6 +1323,19 @@ static int mpam_resctrl_control_init(struct mpam_resctrl_res *res)
 		r->name = (r->rid == RDT_RESOURCE_L2_MIN) ? "L2MIN" : "L3MIN";
 		r->alloc_capable = true;
 		break;
+	case RDT_RESOURCE_MB_MIN:
+		r->schema_fmt = RESCTRL_SCHEMA_RANGE;
+		r->ctrl_scope = RESCTRL_L3_CACHE;
+
+		r->membw.delay_linear = true;
+		r->membw.throttle_mode = THREAD_THROTTLE_UNDEFINED;
+		r->membw.min_bw = 0;
+		r->membw.max_bw = MAX_MBA_BW;
+		r->membw.bw_gran = 1;
+
+		r->name = "MBMIN";
+		r->alloc_capable = true;
+		break;
 	case RDT_RESOURCE_L3_PRI:
 	case RDT_RESOURCE_L2_PRI:
 	case RDT_RESOURCE_MB_PRI:
@@ -1334,6 +1353,32 @@ static int mpam_resctrl_control_init(struct mpam_resctrl_res *res)
 			((r->rid == RDT_RESOURCE_L2_PRI) ? "L2PRI" : "L3PRI");
 		r->alloc_capable = true;
 		break;
+	case RDT_RESOURCE_MB_HDL:
+		r->schema_fmt = RESCTRL_SCHEMA_RANGE;
+		r->ctrl_scope = RESCTRL_L3_CACHE;
+
+		r->membw.delay_linear = true;
+		r->membw.throttle_mode = THREAD_THROTTLE_UNDEFINED;
+		r->membw.min_bw = 0;
+		r->membw.max_bw = 1;
+		r->membw.bw_gran = 1;
+
+		r->name = "MBHDL";
+		r->alloc_capable = true;
+		break;
+	case RDT_RESOURCE_MB_OPT:
+		r->schema_fmt = RESCTRL_SCHEMA_RANGE;
+		r->ctrl_scope = RESCTRL_L3_CACHE;
+
+		r->membw.delay_linear = true;
+		r->membw.throttle_mode = THREAD_THROTTLE_UNDEFINED;
+		r->membw.min_bw = 1;
+		r->membw.max_bw = GENMASK(cprops->bwa_wd - 1, 0);
+		r->membw.bw_gran = 1;
+
+		r->name = "MBOPT";
+		r->alloc_capable = true;
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -1511,6 +1556,15 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
 	case RDT_RESOURCE_MB_PRI:
 		configured_by = mpam_feat_intpri_part;
 		break;
+	case RDT_RESOURCE_MB_MIN:
+		configured_by = mpam_feat_mbw_min;
+		break;
+	case RDT_RESOURCE_MB_HDL:
+		configured_by = mpam_feat_max_limit;
+		break;
+	case RDT_RESOURCE_MB_OPT:
+		configured_by = mpam_feat_mbw_max;
+		break;
 	case RDT_RESOURCE_MBA:
 		if (mpam_has_feature(mpam_feat_mbw_max, cprops)) {
 			configured_by = mpam_feat_mbw_max;
@@ -1534,7 +1588,14 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
 		return ca_max_to_percent(cfg->cmin, cprops);
 	case mpam_feat_intpri_part:
 		return cfg->intpri;
+	case mpam_feat_mbw_min:
+		return mbw_max_to_percent(cfg->mbw_min, cprops);
+	case mpam_feat_max_limit:
+		return cfg->max_limit;
 	case mpam_feat_mbw_max:
+		/* MB_OPT exposes the raw fraction, without the percent scaling */
+		if (r->rid == RDT_RESOURCE_MB_OPT)
+			return cfg->mbw_max >> (16 - cprops->bwa_wd);
 		return mbw_max_to_percent(cfg->mbw_max, cprops);
 	default:
 		return resctrl_get_default_ctrl(r);
@@ -1602,6 +1663,18 @@ int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d,
 		cfg.intpri = cfg_val;
 		mpam_set_feature(mpam_feat_intpri_part, &cfg);
 		break;
+	case RDT_RESOURCE_MB_MIN:
+		cfg.mbw_min = percent_to_mbw_max(cfg_val, cprops);
+		mpam_set_feature(mpam_feat_mbw_min, &cfg);
+		break;
+	case RDT_RESOURCE_MB_HDL:
+		cfg.max_limit = !!cfg_val;
+		mpam_set_feature(mpam_feat_max_limit, &cfg);
+		break;
+	case RDT_RESOURCE_MB_OPT:
+		cfg.mbw_max = cfg_val << (16 - cprops->bwa_wd);
+		mpam_set_feature(mpam_feat_mbw_max, &cfg);
+		break;
 	case RDT_RESOURCE_MBA:
 		if (mpam_has_feature(mpam_feat_mbw_max, cprops)) {
 			cfg.mbw_max = percent_to_mbw_max(cfg_val, cprops);
-- 
2.34.1