[PATCH v6 08/12] x86/resctrl: Add sysfs interface to read mbm_local_bytes event configuration

[Babu Moger]

The current event configuration can be viewed by the user by reading
the configuration file /sys/fs/resctrl/info/L3_MON/mbm_local_config.

Following are the types of events supported:

====  ===========================================================
Bits   Description
====  ===========================================================
6      Dirty Victims from the QOS domain to all types of memory
5      Reads to slow memory in the non-local NUMA domain
4      Reads to slow memory in the local NUMA domain
3      Non-temporal writes to non-local NUMA domain
2      Non-temporal writes to local NUMA domain
1      Reads to memory in the non-local NUMA domain
0      Reads to memory in the local NUMA domain
====  ===========================================================

By default, the mbm_local_bytes configuration is set to 0x15 to count
all the local event types. The event configuration settings are domain
specific. Changing the configuration on one CPU in a domain would
affect the whole domain.

For example:
    $cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
    0=0x15;1=0x15;2=0x15;3=0x15

    In this case the event mbm_local_bytes is currently configured with
    0x15 on domains 0 to 3.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |   20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 0982845594d0..305fb0475970 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1484,6 +1484,16 @@ static int mbm_total_config_show(struct kernfs_open_file *of,
 	return 0;
 }
 
+static int mbm_local_config_show(struct kernfs_open_file *of,
+				 struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+
+	mbm_config_show(seq, r, QOS_L3_MBM_LOCAL_EVENT_ID);
+
+	return 0;
+}
+
 /* rdtgroup information files for one cache resource. */
 static struct rftype res_common_files[] = {
 	{
@@ -1588,6 +1598,12 @@ static struct rftype res_common_files[] = {
 		.kf_ops		= &rdtgroup_kf_single_ops,
 		.seq_show	= mbm_total_config_show,
 	},
+	{
+		.name		= "mbm_local_config",
+		.mode		= 0644,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= mbm_local_config_show,
+	},
 	{
 		.name		= "cpus",
 		.mode		= 0644,
@@ -1701,6 +1717,10 @@ void __init mbm_config_rftype_init(void)
 	rft = rdtgroup_get_rftype_by_name("mbm_total_config");
 	if (rft)
 		rft->fflags = RF_MON_INFO | RFTYPE_RES_CACHE;
+
+	rft = rdtgroup_get_rftype_by_name("mbm_local_config");
+	if (rft)
+		rft->fflags = RF_MON_INFO | RFTYPE_RES_CACHE;
 }
 
 /**