[PATCH v5 4/8] x86/resctrl: Add comments on RFTYPE flags hierarchy

[Babu Moger <babu.moger@amd.com>]

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@amd.com>
---
 arch/x86/kernel/cpu/resctrl/internal.h |   45 ++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 2051179a3b91..c20cd6acb7a3 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -240,6 +240,51 @@ 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 (directory and provides details on control
+ *     |         and monitoring resources)
+ *     |
+ *     --> base (Lists the files and information to interact with control
+ *               or monitor groups. Provides details on default control
+ *               group when filesystem is created. There is no directory
+ *               with name base)
+ *
+ *     info structure
+ *    -------------------------------------------------------------
+ *    --> RFTYPE_INFO
+ *        --> <info> directory
+ *            --> RFTYPE_TOP_INFO
+ *                Files: last_cmd_status
+ *
+ *        --> RFTYPE_MON_INFO
+ *            --> <L3_MON> directory
+ *                 Files: max_threshold_occupancy, mbm_local_bytes_config,
+ *                        mbm_total_bytes_config, mon_features, num_rmids
+ *
+ *        --> RFTYPE_CTRL_INFO
+ *            --> RFTYPE_RES_CACHE
+ *                --> <L2/L3> directory
+ *                     Files: bit_usage, cbm_mask, min_cbm_bits,
+ *                            num_closids, shareable_bits
+ *
+ *            --> RFTYPE_RES_MB
+ *                --> <MB/SMBA> directory
+ *                     Files: bandwidth_gran, delay_linear, min_bandwidth,
+ *                            num_closids
+ *
+ *     base 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)