[tip:,x86/cache] Documentation/x86: Update resctrl.rst for new features

diff --git a/Documentation/x86/resctrl.rst b/Documentation/x86/resctrl.rst
index 71a5310..058257d 100644
--- a/Documentation/x86/resctrl.rst
+++ b/Documentation/x86/resctrl.rst
@@ -17,14 +17,21 @@  AMD refers to this feature as AMD Platform Quality of Service(AMD QoS).
 This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo
 flag bits:
 
-=============================================	================================
+===============================================	================================
 RDT (Resource Director Technology) Allocation	"rdt_a"
 CAT (Cache Allocation Technology)		"cat_l3", "cat_l2"
 CDP (Code and Data Prioritization)		"cdp_l3", "cdp_l2"
 CQM (Cache QoS Monitoring)			"cqm_llc", "cqm_occup_llc"
 MBM (Memory Bandwidth Monitoring)		"cqm_mbm_total", "cqm_mbm_local"
 MBA (Memory Bandwidth Allocation)		"mba"
-=============================================	================================
+SMBA (Slow Memory Bandwidth Allocation)         ""
+BMEC (Bandwidth Monitoring Event Configuration) ""
+===============================================	================================
+
+Historically, new features were made visible by default in /proc/cpuinfo. This
+resulted in the feature flags becoming hard to parse by humans. Adding a new
+flag to /proc/cpuinfo should be avoided if user space can obtain information
+about the feature from resctrl's info directory.
 
 To use the feature mount the file system::
 
@@ -161,6 +168,83 @@  with the following files:
 "mon_features":
 		Lists the monitoring events if
 		monitoring is enabled for the resource.
+		Example::
+
+			# cat /sys/fs/resctrl/info/L3_MON/mon_features
+			llc_occupancy
+			mbm_total_bytes
+			mbm_local_bytes
+
+		If the system supports Bandwidth Monitoring Event
+		Configuration (BMEC), then the bandwidth events will
+		be configurable. The output will be::
+
+			# cat /sys/fs/resctrl/info/L3_MON/mon_features
+			llc_occupancy
+			mbm_total_bytes
+			mbm_total_bytes_config
+			mbm_local_bytes
+			mbm_local_bytes_config
+
+"mbm_total_bytes_config", "mbm_local_bytes_config":
+	Read/write files containing the configuration for the mbm_total_bytes
+	and mbm_local_bytes events, respectively, when the Bandwidth
+	Monitoring Event Configuration (BMEC) feature is supported.
+	The event configuration settings are domain specific and affect
+	all the CPUs in the domain. When either event configuration is
+	changed, the bandwidth counters for all RMIDs of both events
+	(mbm_total_bytes as well as mbm_local_bytes) are cleared for that
+	domain. The next read for every RMID will report "Unavailable"
+	and subsequent reads will report the valid value.
+
+	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_total_bytes configuration is set to 0x7f to count
+	all the event types and the mbm_local_bytes configuration is set to
+	0x15 to count all the local memory events.
+
+	Examples:
+
+	* To view the current configuration::
+	  ::
+
+	    # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
+	    0=0x7f;1=0x7f;2=0x7f;3=0x7f
+
+	    # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
+	    0=0x15;1=0x15;3=0x15;4=0x15
+
+	* To change the mbm_total_bytes to count only reads on domain 0,
+	  the bits 0, 1, 4 and 5 needs to be set, which is 110011b in binary
+	  (in hexadecimal 0x33):
+	  ::
+
+	    # echo  "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
+
+	    # cat /sys/fs/resctrl/info/L3_MON/mbm_total_bytes_config
+	    0=0x33;1=0x7f;2=0x7f;3=0x7f
+
+	* To change the mbm_local_bytes to count all the slow memory reads on
+	  domain 0 and 1, the bits 4 and 5 needs to be set, which is 110000b
+	  in binary (in hexadecimal 0x30):
+	  ::
+
+	    # echo  "0=0x30;1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
+
+	    # cat /sys/fs/resctrl/info/L3_MON/mbm_local_bytes_config
+	    0=0x30;1=0x30;3=0x15;4=0x15
 
 "max_threshold_occupancy":
 		Read/write file provides the largest value (in
@@ -464,6 +548,25 @@  Memory bandwidth domain is L3 cache.
 
 	MB:<cache_id0>=bw_MBps0;<cache_id1>=bw_MBps1;...
 
+Slow Memory Bandwidth Allocation (SMBA)
+---------------------------------------
+AMD hardware supports Slow Memory Bandwidth Allocation (SMBA).
+CXL.memory is the only supported "slow" memory device. With the
+support of SMBA, the hardware enables bandwidth allocation on
+the slow memory devices. If there are multiple such devices in
+the system, the throttling logic groups all the slow sources
+together and applies the limit on them as a whole.
+
+The presence of SMBA (with CXL.memory) is independent of slow memory
+devices presence. If there are no such devices on the system, then
+configuring SMBA will have no impact on the performance of the system.
+
+The bandwidth domain for slow memory is L3 cache. Its schemata file
+is formatted as:
+::
+
+	SMBA:<cache_id0>=bandwidth0;<cache_id1>=bandwidth1;...
+
 Reading/writing the schemata file
 ---------------------------------
 Reading the schemata file will show the state of all resources
@@ -479,6 +582,46 @@  which you wish to change.  E.g.
   L3DATA:0=fffff;1=fffff;2=3c0;3=fffff
   L3CODE:0=fffff;1=fffff;2=fffff;3=fffff
 
+Reading/writing the schemata file (on AMD systems)
+--------------------------------------------------
+Reading the schemata file will show the current bandwidth limit on all
+domains. The allocated resources are in multiples of one eighth GB/s.
+When writing to the file, you need to specify what cache id you wish to
+configure the bandwidth limit.
+
+For example, to allocate 2GB/s limit on the first cache id:
+
+::
+
+  # cat schemata
+    MB:0=2048;1=2048;2=2048;3=2048
+    L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+  # echo "MB:1=16" > schemata
+  # cat schemata
+    MB:0=2048;1=  16;2=2048;3=2048
+    L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+Reading/writing the schemata file (on AMD systems) with SMBA feature
+--------------------------------------------------------------------
+Reading and writing the schemata file is the same as without SMBA in
+above section.
+
+For example, to allocate 8GB/s limit on the first cache id:
+
+::
+
+  # cat schemata
+    SMBA:0=2048;1=2048;2=2048;3=2048
+      MB:0=2048;1=2048;2=2048;3=2048
+      L3:0=ffff;1=ffff;2=ffff;3=ffff
+
+  # echo "SMBA:1=64" > schemata
+  # cat schemata
+    SMBA:0=2048;1=  64;2=2048;3=2048
+      MB:0=2048;1=2048;2=2048;3=2048
+      L3:0=ffff;1=ffff;2=ffff;3=ffff
+
 Cache Pseudo-Locking
 ====================
 CAT enables a user to specify the amount of cache space that an