[PATCH v7 14/24] x86/resctrl: Introduce cntr_id in mongroup for assignments

[Babu Moger]

mbm_cntr_assign feature provides an option to the user to assign a
hardware counter to an RMID and monitor the bandwidth as long as the
counter is assigned. There can be two counters per monitor group, one
for total event and another for local event.

Introduce cntr_id to manage the assignments.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v7: Minor comment update for cntr_id.

v6: New patch.
    Separated FS and arch bits.
---
 arch/x86/kernel/cpu/resctrl/internal.h | 7 +++++++
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 6 ++++++
 2 files changed, 13 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 27617fe592ed..e0ae8b0b45b2 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -62,6 +62,11 @@
 /* Setting bit 0 in L3_QOS_EXT_CFG enables the ABMC feature. */
 #define ABMC_ENABLE_BIT			0
 
+/* Maximum assignable counters per resctrl group */
+#define MAX_CNTRS			2
+
+#define MON_CNTR_UNSET			U32_MAX
+
 /**
  * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that
  *			        aren't marked nohz_full
@@ -231,12 +236,14 @@ enum rdtgrp_mode {
  * @parent:			parent rdtgrp
  * @crdtgrp_list:		child rdtgroup node list
  * @rmid:			rmid for this rdtgroup
+ * @cntr_id:			IDs of hardware counters assigned to monitor group
  */
 struct mongroup {
 	struct kernfs_node	*mon_data_kn;
 	struct rdtgroup		*parent;
 	struct list_head	crdtgrp_list;
 	u32			rmid;
+	u32			cntr_id[MAX_CNTRS];
 };
 
 /**
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index a014d5f4c0b3..7fa92143daa7 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -3529,6 +3529,9 @@ static int mkdir_rdt_prepare_rmid_alloc(struct rdtgroup *rdtgrp)
 	}
 	rdtgrp->mon.rmid = ret;
 
+	rdtgrp->mon.cntr_id[0] = MON_CNTR_UNSET;
+	rdtgrp->mon.cntr_id[1] = MON_CNTR_UNSET;
+
 	ret = mkdir_mondata_all(rdtgrp->kn, rdtgrp, &rdtgrp->mon.mon_data_kn);
 	if (ret) {
 		rdt_last_cmd_puts("kernfs subdir error\n");
@@ -4083,6 +4086,9 @@ static void __init rdtgroup_setup_default(void)
 	rdtgroup_default.closid = RESCTRL_RESERVED_CLOSID;
 	rdtgroup_default.mon.rmid = RESCTRL_RESERVED_RMID;
 	rdtgroup_default.type = RDTCTRL_GROUP;
+	rdtgroup_default.mon.cntr_id[0] = MON_CNTR_UNSET;
+	rdtgroup_default.mon.cntr_id[1] = MON_CNTR_UNSET;
+
 	INIT_LIST_HEAD(&rdtgroup_default.mon.crdtgrp_list);
 
 	list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);
-- 
2.34.1