Add Smcdeleg CSR+constants

Adds CSR scountinhibit (0x120), MSTATEEN0.CD (bit 56), and siselect
range (0x40 - 0x5F).

constants.py

@@ -108,6 +108,7 @@
   (0x10D, 'sstateen1'), # Smstateen
   (0x10E, 'sstateen2'), # Smstateen
   (0x10F, 'sstateen3'), # Smstateen
+  (0x120, 'scountinhibit'), # Smcdeleg
   (0x140, 'sscratch'),
   (0x141, 'sepc'),
   (0x142, 'scause'),

encoding.h

@@ -163,6 +163,7 @@
 #define MSTATEEN0_FCSR     0x00000002
 #define MSTATEEN0_JVT      0x00000004
 #define MSTATEEN0_HCONTEXT 0x0200000000000000
+#define MSTATEEN0_CD       0x0100000000000000
 #define MSTATEEN0_HENVCFG  0x4000000000000000
 #define MSTATEEN_HSTATEEN  0x8000000000000000
 
@@ -196,6 +197,18 @@
 #define HENVCFGH_PBMTE 0x40000000
 #define HENVCFGH_STCE  0x80000000
 
+#define SISELECT_SMCDELEG_START       0x40
+#define SISELECT_SMCDELEG_UNUSED      0x41
+#define SISELECT_SMCDELEG_INSTRET     0x42
+#define SISELECT_SMCDELEG_INSTRETCFG  0x42
+/*
+ * ?iselect values for hpmcounters4..31 and hpmevent4..31
+ * can easily computed, and were elided for brevity.
+ */
+#define SISELECT_SMCDELEG_HPMCOUNTER_3  0x43
+#define SISELECT_SMCDELEG_HPMEVENT_3    0x43
+#define SISELECT_SMCDELEG_END           0x5f
+
 #define HSTATEEN0_CS       0x00000001
 #define HSTATEEN0_FCSR     0x00000002
 #define HSTATEEN0_JVT      0x00000004