perf/mem: Introduce PERF_MEM_LVLNUM_{EXTN_MEM|IO}

PERF_MEM_LVLNUM_EXTN_MEM which can be used to indicate accesses to
extension memory like CXL etc. PERF_MEM_LVL_IO can be used for IO
accesses but it can not distinguish between local and remote IO.
Introduce new field PERF_MEM_LVLNUM_IO which can be clubbed with
PERF_MEM_REMOTE_REMOTE to indicate Remote IO accesses.

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220928095805.596-2-ravi.bangoria@amd.com

Author: Ravi Bangoria

include/uapi/linux/perf_event.h

@@ -1336,7 +1336,9 @@ union perf_mem_data_src {
 #define PERF_MEM_LVLNUM_L2	0x02 /* L2 */
 #define PERF_MEM_LVLNUM_L3	0x03 /* L3 */
 #define PERF_MEM_LVLNUM_L4	0x04 /* L4 */
-/* 5-0xa available */
+/* 5-0x8 available */
+#define PERF_MEM_LVLNUM_EXTN_MEM 0x09 /* Extension memory */
+#define PERF_MEM_LVLNUM_IO	0x0a /* I/O */
 #define PERF_MEM_LVLNUM_ANY_CACHE 0x0b /* Any cache */
 #define PERF_MEM_LVLNUM_LFB	0x0c /* LFB */
 #define PERF_MEM_LVLNUM_RAM	0x0d /* RAM */