[PATCH v7 4/8] x86/resctrl: Add comments on RFTYPE flags hierarchy

[Babu Moger]

resctrl uses RFTYPE flags for creating resctrl directory structure.

Definitions and directory structures are not documented. Add
comments to improve the readability and help future additions.

Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
 arch/x86/kernel/cpu/resctrl/internal.h |   49 ++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 2051179a3b91..37800724e002 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -240,6 +240,55 @@ struct rdtgroup {
 
 /*
  * Define the file type flags for base and info directories.
+ *
+ * RESCTRL filesystem has two main components
+ *	a. info
+ *	b. base
+ *
+ * /sys/fs/resctrl/
+ *	|
+ *	--> info (Top level directory named "info". Contains files that
+ *	|	  provide details on control and monitoring resources.)
+ *	|
+ *	--> base (Root directory associated with default resource group
+ *		  as well as directories created by user for MON and CTRL
+ *		  groups. Contains files to interact with MON and CTRL
+ *		  groups.)
+ *
+ *	info directory structure
+ *	------------------------------------------------------------------
+ *	--> RFTYPE_INFO
+ *	--> <info> directory
+ *		--> RFTYPE_TOP_INFO
+ *		    Files: last_cmd_status
+ *
+ *		--> RFTYPE_MON_INFO
+ *		--> <L3_MON> directory
+ *		    Files: max_threshold_occupancy, mon_features,
+ *			   num_rmids, mbm_total_bytes_config,
+ *			   mbm_local_bytes_config
+ *
+ *		--> RFTYPE_CTRL_INFO
+ *		    Files: num_closids
+ *
+ *			--> RFTYPE_RES_CACHE
+ *			--> <L2,L3> directories
+ *			    Files: bit_usage, cbm_mask, min_cbm_bits,
+ *				   shareable_bits
+ *
+ *			--> RFTYPE_RES_MB
+ *			--> <MB,SMBA> directories
+ *			    Files: bandwidth_gran, delay_linear,
+ *				   min_bandwidth, thread_throttle_mode
+ *
+ *	base directory structure
+ *	------------------------------------------------------------------
+ *	--> RFTYPE_BASE (Files common for both MON and CTRL groups)
+ *	    Files: cpus, cpus_list, tasks
+ *
+ *	--> RFTYPE_CTRL_BASE (Files only for CTRL group)
+ *	    Files: mode, schemata, size
+ *
  */
 #define RFTYPE_INFO			BIT(0)
 #define RFTYPE_BASE			BIT(1)