[PATCH v18 07/17] x86/resctrl: Prepare for new Sub-NUMA (SNC) cluster monitor files

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

When SNC is enabled monitoring data is collected at the SNC node
granularity, but must be reported at L3-cache granularity for
backwards compatibility in addition to reporting at the node
level.

Add a mon_display_scope field to the rdt_resource structure to track
reporting scope. Default is for non-SNC systems where both scopes
are the same.

This is the first step to an eventual goal of monitor reporting files
like this (for a system with two SNC nodes per L3):

$ cd /sys/fs/resctrl/mon_data
$ tree mon_L3_00
mon_L3_00			<- 00 here is L3 cache id
├── llc_occupancy		\  These files provide legacy support
├── mbm_local_bytes		 > for non-SNC aware monitor apps
├── mbm_total_bytes		/  that expect data at L3 cache level
├── mon_sub_L3_00		<- 00 here is SNC node id
│   ├── llc_occupancy		\  These files are finer grained
│   ├── mbm_local_bytes		 > data from each SNC node
│   └── mbm_total_bytes		/
└── mon_sub_L3_01
    ├── llc_occupancy		\
    ├── mbm_local_bytes		 > As above, but for node 1.
    └── mbm_total_bytes		/

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 include/linux/resctrl.h            | 2 ++
 arch/x86/kernel/cpu/resctrl/core.c | 1 +
 2 files changed, 3 insertions(+)

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 5c7775343c3e..98c0ff8ba005 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -187,6 +187,7 @@ enum resctrl_scope {
  * @num_rmid:		Number of RMIDs available
  * @ctrl_scope:		Scope of this resource for control functions
  * @mon_scope:		Scope of this resource for monitor functions
+ * @mon_display_scope:	Scope for user reporting monitor functions
  * @cache:		Cache allocation related data
  * @membw:		If the component has bandwidth controls, their properties.
  * @ctrl_domains:	RCU list of all control domains for this resource
@@ -207,6 +208,7 @@ struct rdt_resource {
 	int			num_rmid;
 	enum resctrl_scope	ctrl_scope;
 	enum resctrl_scope	mon_scope;
+	enum resctrl_scope	mon_display_scope;
 	struct resctrl_cache	cache;
 	struct resctrl_membw	membw;
 	struct list_head	ctrl_domains;
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index bfa9d3a429fd..15856254fea7 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -71,6 +71,7 @@ struct rdt_hw_resource rdt_resources_all[] = {
 			.name			= "L3",
 			.ctrl_scope		= RESCTRL_L3_CACHE,
 			.mon_scope		= RESCTRL_L3_CACHE,
+			.mon_display_scope	= RESCTRL_L3_CACHE,
 			.ctrl_domains		= ctrl_domain_init(RDT_RESOURCE_L3),
 			.mon_domains		= mon_domain_init(RDT_RESOURCE_L3),
 			.parse_ctrlval		= parse_cbm,
-- 
2.44.0