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

3 files changed, 66 insertions, 12 deletions

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 41ae6ba3c2..8b610ded23 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -228,17 +228,25 @@ static void arm_cpu_reset(CPUState *s)
     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 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
         }
 
         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);
+            }
         }
     }
 
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 92771d3790..9fd5de7313 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -522,6 +522,19 @@ typedef struct CPUARMState {
         uint32_t rnr;
     } pmsav7;
 
+    /* PMSAv8 MPU */
+    struct {
+        /* The PMSAv8 implementation also shares some PMSAv7 config
+         * and state:
+         *  pmsav7.rnr (region number register)
+         *  pmsav7_dregion (number of configured regions)
+         */
+        uint32_t *rbar;
+        uint32_t *rlar;
+        uint32_t mair0;
+        uint32_t mair1;
+    } pmsav8;
+
     void *nvic;
     const struct arm_boot_info *boot_info;
     /* Store GICv3CPUState to access from this struct */
diff --git a/target/arm/machine.c b/target/arm/machine.c
index 3193b00b04..7b6f9dec6b 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -159,7 +159,8 @@ static bool pmsav7_needed(void *opaque)
     CPUARMState *env = &cpu->env;
 
     return arm_feature(env, ARM_FEATURE_PMSA) &&
-           arm_feature(env, ARM_FEATURE_V7);
+           arm_feature(env, ARM_FEATURE_V7) &&
+           !arm_feature(env, ARM_FEATURE_V8);
 }
 
 static bool pmsav7_rgnr_vmstate_validate(void *opaque, int version_id)
@@ -209,6 +210,31 @@ static const VMStateDescription vmstate_pmsav7_rnr = {
     }
 };
 
+static bool pmsav8_needed(void *opaque)
+{
+    ARMCPU *cpu = opaque;
+    CPUARMState *env = &cpu->env;
+
+    return arm_feature(env, ARM_FEATURE_PMSA) &&
+        arm_feature(env, ARM_FEATURE_V8);
+}
+
+static const VMStateDescription vmstate_pmsav8 = {
+    .name = "cpu/pmsav8",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = pmsav8_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_VARRAY_UINT32(env.pmsav8.rbar, ARMCPU, pmsav7_dregion, 0,
+                              vmstate_info_uint32, uint32_t),
+        VMSTATE_VARRAY_UINT32(env.pmsav8.rlar, ARMCPU, pmsav7_dregion, 0,
+                              vmstate_info_uint32, uint32_t),
+        VMSTATE_UINT32(env.pmsav8.mair0, ARMCPU),
+        VMSTATE_UINT32(env.pmsav8.mair1, ARMCPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static int get_cpsr(QEMUFile *f, void *opaque, size_t size,
                     VMStateField *field)
 {
@@ -458,6 +484,7 @@ const VMStateDescription vmstate_arm_cpu = {
          */
         &vmstate_pmsav7_rnr,
         &vmstate_pmsav7,
+        &vmstate_pmsav8,
         NULL
     }
 };