target/arm: Implement ARMv8M's PMSAv8 registers

As part of ARMv8M, we need to add support for the PMSAv8 MPU
architecture.

PMSAv8 differs from PMSAv7 both in register/data layout (for instance
using base and limit registers rather than base and size) and also in
behaviour (for example it does not have subregions); rather than
trying to wedge it into the existing PMSAv7 code and data structures,
we define separate ones.

This commit adds the data structures which hold the state for a
PMSAv8 MPU and the register interface to it.  The implementation of
the MPU behaviour will be added in a subsequent commit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 1503414539-28762-2-git-send-email-peter.maydell@linaro.org
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 41ae6ba..8b610de 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -228,17 +228,25 @@
     env->vfp.xregs[ARM_VFP_FPEXC] = 0;
 #endif
 
-    if (arm_feature(env, ARM_FEATURE_PMSA) &&
-        arm_feature(env, ARM_FEATURE_V7)) {
+    if (arm_feature(env, ARM_FEATURE_PMSA)) {
         if (cpu->pmsav7_dregion > 0) {
-            memset(env->pmsav7.drbar, 0,
-                   sizeof(*env->pmsav7.drbar) * cpu->pmsav7_dregion);
-            memset(env->pmsav7.drsr, 0,
-                   sizeof(*env->pmsav7.drsr) * cpu->pmsav7_dregion);
-            memset(env->pmsav7.dracr, 0,
-                   sizeof(*env->pmsav7.dracr) * cpu->pmsav7_dregion);
+            if (arm_feature(env, ARM_FEATURE_V8)) {
+                memset(env->pmsav8.rbar, 0,
+                       sizeof(*env->pmsav8.rbar) * cpu->pmsav7_dregion);
+                memset(env->pmsav8.rlar, 0,
+                       sizeof(*env->pmsav8.rlar) * cpu->pmsav7_dregion);
+            } else if (arm_feature(env, ARM_FEATURE_V7)) {
+                memset(env->pmsav7.drbar, 0,
+                       sizeof(*env->pmsav7.drbar) * cpu->pmsav7_dregion);
+                memset(env->pmsav7.drsr, 0,
+                       sizeof(*env->pmsav7.drsr) * cpu->pmsav7_dregion);
+                memset(env->pmsav7.dracr, 0,
+                       sizeof(*env->pmsav7.dracr) * cpu->pmsav7_dregion);
+            }
         }
         env->pmsav7.rnr = 0;
+        env->pmsav8.mair0 = 0;
+        env->pmsav8.mair1 = 0;
     }
 
     set_flush_to_zero(1, &env->vfp.standard_fp_status);
@@ -809,9 +817,15 @@
         }
 
         if (nr) {
-            env->pmsav7.drbar = g_new0(uint32_t, nr);
-            env->pmsav7.drsr = g_new0(uint32_t, nr);
-            env->pmsav7.dracr = g_new0(uint32_t, nr);
+            if (arm_feature(env, ARM_FEATURE_V8)) {
+                /* PMSAv8 */
+                env->pmsav8.rbar = g_new0(uint32_t, nr);
+                env->pmsav8.rlar = g_new0(uint32_t, nr);
+            } else {
+                env->pmsav7.drbar = g_new0(uint32_t, nr);
+                env->pmsav7.drsr = g_new0(uint32_t, nr);
+                env->pmsav7.dracr = g_new0(uint32_t, nr);
+            }
         }
     }