[PATCH v8 5/7] x86/resctrl: Add "mba_MBps_event" file to ctrl_mon directories

[Tony Luck <tony.luck@intel.com>]

When the mba_MBps mount option is used, provide a file in each
ctrl_mon directory to show which memory monitoring event is
being used.

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 arch/x86/kernel/cpu/resctrl/internal.h    |  2 ++
 arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 25 +++++++++++++++++++++++
 arch/x86/kernel/cpu/resctrl/rdtgroup.c    | 17 +++++++++++++++
 3 files changed, 44 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index a6f051fb2e69..5f3438ca9e2b 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -609,6 +609,8 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 				char *buf, size_t nbytes, loff_t off);
 int rdtgroup_schemata_show(struct kernfs_open_file *of,
 			   struct seq_file *s, void *v);
+int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
+				 struct seq_file *s, void *v);
 bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d,
 			   unsigned long cbm, int closid, bool exclusive);
 unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_ctrl_domain *d,
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 200d89a64027..b9ba419e5c88 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -518,6 +518,31 @@ static int smp_mon_event_count(void *arg)
 	return 0;
 }
 
+int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
+				 struct seq_file *s, void *v)
+{
+	struct rdtgroup *rdtgrp;
+
+	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+
+	if (rdtgrp) {
+		switch (rdtgrp->mba_mbps_event) {
+		case QOS_L3_MBM_LOCAL_EVENT_ID:
+			seq_puts(s, "mbm_local_bytes\n");
+			break;
+		case QOS_L3_MBM_TOTAL_EVENT_ID:
+			seq_puts(s, "mbm_total_bytes\n");
+			break;
+		case QOS_L3_OCCUP_EVENT_ID:
+			break;
+		}
+	}
+
+	rdtgroup_kn_unlock(of->kn);
+
+	return 0;
+}
+
 void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
 		    struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
 		    cpumask_t *cpumask, int evtid, int first)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 5034a3dd0430..3ba81963e981 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1943,6 +1943,12 @@ static struct rftype res_common_files[] = {
 		.seq_show	= rdtgroup_schemata_show,
 		.fflags		= RFTYPE_CTRL_BASE,
 	},
+	{
+		.name		= "mba_MBps_event",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdtgroup_mba_mbps_event_show,
+	},
 	{
 		.name		= "mode",
 		.mode		= 0644,
@@ -2042,6 +2048,15 @@ void __init mbm_config_rftype_init(const char *config)
 		rft->fflags = RFTYPE_MON_INFO | RFTYPE_RES_CACHE;
 }
 
+static void mba_mbps_event_init(bool enable)
+{
+	struct rftype *rft;
+
+	rft = rdtgroup_get_rftype_by_name("mba_MBps_event");
+	if (rft)
+		rft->fflags = enable ? RFTYPE_CTRL_BASE : 0;
+}
+
 /**
  * rdtgroup_kn_mode_restrict - Restrict user access to named resctrl file
  * @r: The resource group with which the file is associated.
@@ -2371,6 +2386,8 @@ static int set_mba_sc(bool mba_sc)
 			d->mbps_val[i] = MBA_MAX_MBPS;
 	}
 
+	mba_mbps_event_init(mba_sc);
+
 	return 0;
 }
 
-- 
2.47.0