[RFC PATCH v3 06/17] x86/resctrl: Introduce interface to display number of ABMC counters

Babu Moger
2024-03-29T01:07:50Z

The ABMC feature provides an option to the user to pin (or assign) the
RMID to the hardware counter and monitor the bandwidth for a longer
duration. There are only a limited number of hardware counters.

Provide the interface to display the number of ABMC counters supported.

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
v3: Changed the field name to mbm_assign_cntrs.

v2: Changed the field name to mbm_assignable_counters from abmc_counters.
---
Documentation/arch/x86/resctrl.rst | 4 ++++
arch/x86/kernel/cpu/resctrl/monitor.c | 1 +
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 ++++++++++++++++
3 files changed, 21 insertions(+)

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index cd973a013525..e06ffddb64f6 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -262,6 +262,10 @@ with the following files:
Reports the list of assignable features supported and the enclosed brackets
indicate the feature is enabled.

+"mbm_assign_cntrs":
+ The number of assignable counters available when the assignable monitoring
+ feature is supported.
+
"max_threshold_occupancy":
Read/write file provides the largest value (in
bytes) at which a previously used LLC_occupancy
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 48d1957ea5a3..56dc49021540 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1061,6 +1061,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
if (resctrl_arch_has_abmc(r)) {
r->mbm_assign_capable = ABMC_ASSIGN;
resctrl_file_fflags_init("mbm_assign", RFTYPE_MON_INFO);
+ resctrl_file_fflags_init("mbm_assign_cntrs", RFTYPE_MON_INFO);
}
}

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 5ec807e8dd38..05f551bc316e 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -857,6 +857,16 @@ static int rdtgroup_mbm_assign_show(struct kernfs_open_file *of,
return 0;
}

+static int rdtgroup_mbm_assign_cntrs_show(struct kernfs_open_file *of,
+ struct seq_file *s, void *v)
+{
+ struct rdt_resource *r = of->kn->parent->priv;
+
+ seq_printf(s, "%d\n", r->mbm_assign_cntrs);
+
+ return 0;
+}
+
#ifdef CONFIG_PROC_CPU_RESCTRL

/*
@@ -1920,6 +1930,12 @@ static struct rftype res_common_files[] = {
.kf_ops = &rdtgroup_kf_single_ops,
.seq_show = rdtgroup_mbm_assign_show,
},
+ {
+ .name = "mbm_assign_cntrs",
+ .mode = 0444,
+ .kf_ops = &rdtgroup_kf_single_ops,
+ .seq_show = rdtgroup_mbm_assign_cntrs_show,
+ },
{
.name = "cpus",
.mode = 0644,
--
2.34.1