target/arm: Move mode specific TB flags to tb->cs_base

Now that we have all of the proper macros defined, expanding
the CPUARMTBFlags structure and populating the two TB fields
is relatively simple.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210419202257.161730-7-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 79af9a7..a8da7c5 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -228,6 +228,7 @@
 /* See the commentary above the TBFLAG field definitions.  */
 typedef struct CPUARMTBFlags {
     uint32_t flags;
+    target_ulong flags2;
 } CPUARMTBFlags;
 
 typedef struct CPUARMState {
@@ -3381,20 +3382,26 @@
 #include "exec/cpu-all.h"
 
 /*
- * Bit usage in the TB flags field: bit 31 indicates whether we are
- * in 32 or 64 bit mode. The meaning of the other bits depends on that.
- * We put flags which are shared between 32 and 64 bit mode at the top
- * of the word, and flags which apply to only one mode at the bottom.
+ * We have more than 32-bits worth of state per TB, so we split the data
+ * between tb->flags and tb->cs_base, which is otherwise unused for ARM.
+ * We collect these two parts in CPUARMTBFlags where they are named
+ * flags and flags2 respectively.
  *
- *  31          20    18    14          9              0
- * +--------------+-----+-----+----------+--------------+
- * |              |     |   TBFLAG_A32   |              |
- * |              |     +-----+----------+  TBFLAG_AM32 |
- * |  TBFLAG_ANY  |           |TBFLAG_M32|              |
- * |              +-----------+----------+--------------|
- * |              |            TBFLAG_A64               |
- * +--------------+-------------------------------------+
- *  31          20                                     0
+ * The flags that are shared between all execution modes, TBFLAG_ANY,
+ * are stored in flags.  The flags that are specific to a given mode
+ * are stores in flags2.  Since cs_base is sized on the configured
+ * address size, flags2 always has 64-bits for A64, and a minimum of
+ * 32-bits for A32 and M32.
+ *
+ * The bits for 32-bit A-profile and M-profile partially overlap:
+ *
+ *  18             9              0
+ * +----------------+--------------+
+ * |   TBFLAG_A32   |              |
+ * +-----+----------+  TBFLAG_AM32 |
+ * |     |TBFLAG_M32|              |
+ * +-----+----------+--------------+
+ *     14          9              0
  *
  * Unless otherwise noted, these bits are cached in env->hflags.
  */
@@ -3472,19 +3479,19 @@
 #define DP_TBFLAG_ANY(DST, WHICH, VAL) \
     (DST.flags = FIELD_DP32(DST.flags, TBFLAG_ANY, WHICH, VAL))
 #define DP_TBFLAG_A64(DST, WHICH, VAL) \
-    (DST.flags = FIELD_DP32(DST.flags, TBFLAG_A64, WHICH, VAL))
+    (DST.flags2 = FIELD_DP32(DST.flags2, TBFLAG_A64, WHICH, VAL))
 #define DP_TBFLAG_A32(DST, WHICH, VAL) \
-    (DST.flags = FIELD_DP32(DST.flags, TBFLAG_A32, WHICH, VAL))
+    (DST.flags2 = FIELD_DP32(DST.flags2, TBFLAG_A32, WHICH, VAL))
 #define DP_TBFLAG_M32(DST, WHICH, VAL) \
-    (DST.flags = FIELD_DP32(DST.flags, TBFLAG_M32, WHICH, VAL))
+    (DST.flags2 = FIELD_DP32(DST.flags2, TBFLAG_M32, WHICH, VAL))
 #define DP_TBFLAG_AM32(DST, WHICH, VAL) \
-    (DST.flags = FIELD_DP32(DST.flags, TBFLAG_AM32, WHICH, VAL))
+    (DST.flags2 = FIELD_DP32(DST.flags2, TBFLAG_AM32, WHICH, VAL))
 
 #define EX_TBFLAG_ANY(IN, WHICH)   FIELD_EX32(IN.flags, TBFLAG_ANY, WHICH)
-#define EX_TBFLAG_A64(IN, WHICH)   FIELD_EX32(IN.flags, TBFLAG_A64, WHICH)
-#define EX_TBFLAG_A32(IN, WHICH)   FIELD_EX32(IN.flags, TBFLAG_A32, WHICH)
-#define EX_TBFLAG_M32(IN, WHICH)   FIELD_EX32(IN.flags, TBFLAG_M32, WHICH)
-#define EX_TBFLAG_AM32(IN, WHICH)  FIELD_EX32(IN.flags, TBFLAG_AM32, WHICH)
+#define EX_TBFLAG_A64(IN, WHICH)   FIELD_EX32(IN.flags2, TBFLAG_A64, WHICH)
+#define EX_TBFLAG_A32(IN, WHICH)   FIELD_EX32(IN.flags2, TBFLAG_A32, WHICH)
+#define EX_TBFLAG_M32(IN, WHICH)   FIELD_EX32(IN.flags2, TBFLAG_M32, WHICH)
+#define EX_TBFLAG_AM32(IN, WHICH)  FIELD_EX32(IN.flags2, TBFLAG_AM32, WHICH)
 
 /**
  * cpu_mmu_index: