[PATCH v7 06/12] x86/resctrl: Introduce data structure to support monitor configuration

Babu Moger
2022-10-17T22:27:28Z

Add a new field in mon_evt to support Bandwidth Monitoring Event
Configuration(BMEC) and also update the "mon_features" display.

The sysfs file "mon_features" will display the monitor configuration
if supported.

Before the change.
$cat /sys/fs/resctrl/info/L3_MON/mon_features
llc_occupancy
mbm_total_bytes
mbm_local_bytes

After the change if BMEC is supported.
$cat /sys/fs/resctrl/info/L3_MON/mon_features
llc_occupancy
mbm_total_bytes
mbm_total_config
mbm_local_bytes
mbm_local_config

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
arch/x86/kernel/cpu/resctrl/core.c | 3 ++-
arch/x86/kernel/cpu/resctrl/internal.h | 4 +++-
arch/x86/kernel/cpu/resctrl/monitor.c | 7 ++++++-
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 5 ++++-
4 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index d79f494a4e91..46813b1c50c2 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -814,6 +814,7 @@ static __init bool get_rdt_alloc_resources(void)
static __init bool get_rdt_mon_resources(void)
{
struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
+ bool mon_configurable = rdt_cpu_has(X86_FEATURE_BMEC);

if (rdt_cpu_has(X86_FEATURE_CQM_OCCUP_LLC))
rdt_mon_features |= (1 << QOS_L3_OCCUP_EVENT_ID);
@@ -825,7 +826,7 @@ static __init bool get_rdt_mon_resources(void)
if (!rdt_mon_features)
return false;

- return !rdt_get_mon_l3_config(r);
+ return !rdt_get_mon_l3_config(r, mon_configurable);
}

static __init void __check_quirks_intel(void)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 16e3c6e03c79..b458f768f30c 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -63,11 +63,13 @@ DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);
* struct mon_evt - Entry in the event list of a resource
* @evtid: event id
* @name: name of the event
+ * @configurable: true if the event is configurable
* @list: entry in &rdt_resource->evt_list
*/
struct mon_evt {
enum resctrl_event_id evtid;
char *name;
+ bool configurable;
struct list_head list;
};

@@ -522,7 +524,7 @@ int closids_supported(void);
void closid_free(int closid);
int alloc_rmid(void);
void free_rmid(u32 rmid);
-int rdt_get_mon_l3_config(struct rdt_resource *r);
+int rdt_get_mon_l3_config(struct rdt_resource *r, bool configurable);
void mon_event_count(void *info);
int rdtgroup_mondata_show(struct seq_file *m, void *arg);
void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index efe0c30d3a12..4b8adb7f1c5c 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -746,7 +746,7 @@ static void l3_mon_evt_init(struct rdt_resource *r)
list_add_tail(&mbm_local_event.list, &r->evt_list);
}

-int rdt_get_mon_l3_config(struct rdt_resource *r)
+int rdt_get_mon_l3_config(struct rdt_resource *r, bool configurable)
{
unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
@@ -783,6 +783,11 @@ int rdt_get_mon_l3_config(struct rdt_resource *r)
if (ret)
return ret;

+ if (configurable) {
+ mbm_total_event.configurable = true;
+ mbm_local_event.configurable = true;
+ }
+
l3_mon_evt_init(r);

r->mon_capable = true;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 1271fd1ae2f3..5f0ef1bf4c78 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1001,8 +1001,11 @@ static int rdt_mon_features_show(struct kernfs_open_file *of,
struct rdt_resource *r = of->kn->parent->priv;
struct mon_evt *mevt;

- list_for_each_entry(mevt, &r->evt_list, list)
+ list_for_each_entry(mevt, &r->evt_list, list) {
seq_printf(seq, "%s\n", mevt->name);
+ if (mevt->configurable)
+ seq_printf(seq, "%s_config\n", mevt->name);
+ }

return 0;
}