From: Rohit Mathew <rohit.mathew@arm.com>
Date: Wed, 19 Nov 2025 12:22:59 +0000 (+0000)
Subject: arm_mpam: Probe for long/lwd mbwu counters
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=fdc29a141d6364645509cb20129cba1f84e4c10f;p=thirdparty%2Flinux.git

arm_mpam: Probe for long/lwd mbwu counters

mpam v0.1 and versions above v1.0 support optional long counter for
memory bandwidth monitoring. The MPAMF_MBWUMON_IDR register has fields
indicating support for long counters.

Probe these feature bits.

The mpam_feat_msmon_mbwu feature is used to indicate that bandwidth
monitors are supported, instead of muddling this with which size of
bandwidth monitors, add an explicit 31 bit counter feature.

Signed-off-by: Rohit Mathew <rohit.mathew@arm.com>
[ morse: Added 31bit counter feature to simplify later logic ]
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Ben Horgan <ben.horgan@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com>
Tested-by: Gavin Shan <gshan@redhat.com>
Tested-by: Zeng Heng <zengheng4@huawei.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---

diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
index ecb5ecad50f8b..380386cceb741 100644
--- a/drivers/resctrl/mpam_devices.c
+++ b/drivers/resctrl/mpam_devices.c
@@ -783,25 +783,36 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
 				dev_err_once(dev, "Counters are not usable because not-ready timeout was not provided by firmware.");
 		}
 		if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_MBWU, msmon_features)) {
-			bool hw_managed;
+			bool has_long, hw_managed;
 			u32 mbwumon_idr = mpam_read_partsel_reg(msc, MBWUMON_IDR);
 
 			props->num_mbwu_mon = FIELD_GET(MPAMF_MBWUMON_IDR_NUM_MON, mbwumon_idr);
-			if (props->num_mbwu_mon)
+			if (props->num_mbwu_mon) {
 				mpam_set_feature(mpam_feat_msmon_mbwu, props);
 
-			if (FIELD_GET(MPAMF_MBWUMON_IDR_HAS_RWBW, mbwumon_idr))
-				mpam_set_feature(mpam_feat_msmon_mbwu_rwbw, props);
+				if (FIELD_GET(MPAMF_MBWUMON_IDR_HAS_RWBW, mbwumon_idr))
+					mpam_set_feature(mpam_feat_msmon_mbwu_rwbw, props);
 
-			/* Is NRDY hardware managed? */
-			hw_managed = mpam_ris_hw_probe_hw_nrdy(ris, MBWU);
-			if (hw_managed)
-				mpam_set_feature(mpam_feat_msmon_mbwu_hw_nrdy, props);
+				has_long = FIELD_GET(MPAMF_MBWUMON_IDR_HAS_LONG, mbwumon_idr);
+				if (has_long) {
+					if (FIELD_GET(MPAMF_MBWUMON_IDR_LWD, mbwumon_idr))
+						mpam_set_feature(mpam_feat_msmon_mbwu_63counter, props);
+					else
+						mpam_set_feature(mpam_feat_msmon_mbwu_44counter, props);
+				} else {
+					mpam_set_feature(mpam_feat_msmon_mbwu_31counter, props);
+				}
 
-			/*
-			 * Don't warn about any missing firmware property for
-			 * MBWU NRDY - it doesn't make any sense!
-			 */
+				/* Is NRDY hardware managed? */
+				hw_managed = mpam_ris_hw_probe_hw_nrdy(ris, MBWU);
+				if (hw_managed)
+					mpam_set_feature(mpam_feat_msmon_mbwu_hw_nrdy, props);
+
+				/*
+				 * Don't warn about any missing firmware property for
+				 * MBWU NRDY - it doesn't make any sense!
+				 */
+			}
 		}
 	}
 
diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h
index 218e2f48c7bf2..693a315c47107 100644
--- a/drivers/resctrl/mpam_internal.h
+++ b/drivers/resctrl/mpam_internal.h
@@ -164,6 +164,9 @@ enum mpam_device_features {
 	mpam_feat_msmon_csu_xcl,
 	mpam_feat_msmon_csu_hw_nrdy,
 	mpam_feat_msmon_mbwu,
+	mpam_feat_msmon_mbwu_31counter,
+	mpam_feat_msmon_mbwu_44counter,
+	mpam_feat_msmon_mbwu_63counter,
 	mpam_feat_msmon_mbwu_capture,
 	mpam_feat_msmon_mbwu_rwbw,
 	mpam_feat_msmon_mbwu_hw_nrdy,