arm: Clean up handling of no-MPU PMSA CPUs

ARM CPUs come in two flavours:
 * proper MMU ("VMSA")
 * only an MPU ("PMSA")
For PMSA, the MPU may be implemented, or not (in which case there
is default "always acts the same" behaviour, but it isn't guest
programmable).

QEMU is a bit confused about how we indicate this: we have an
ARM_FEATURE_MPU, but it's not clear whether this indicates
"PMSA, not VMSA" or "PMSA and MPU present" , and sometimes we
use it for one purpose and sometimes the other.

Currently trying to implement a PMSA-without-MPU core won't
work correctly because we turn off the ARM_FEATURE_MPU bit
and then a lot of things which should still exist get
turned off too.

As the first step in cleaning this up, rename the feature
bit to ARM_FEATURE_PMSA, which indicates a PMSA CPU (with
or without MPU).

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 1493122030-32191-5-git-send-email-peter.maydell@linaro.org

1 files changed, 6 insertions, 6 deletions

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 4e8fe1c69d..f844af5673 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -593,7 +593,7 @@ static void arm_cpu_post_init(Object *obj)
                                  &error_abort);
     }
 
-    if (arm_feature(&cpu->env, ARM_FEATURE_MPU)) {
+    if (arm_feature(&cpu->env, ARM_FEATURE_PMSA)) {
         qdev_property_add_static(DEVICE(obj), &arm_cpu_has_mpu_property,
                                  &error_abort);
         if (arm_feature(&cpu->env, ARM_FEATURE_V7)) {
@@ -689,7 +689,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
 
     if (arm_feature(env, ARM_FEATURE_V7) &&
         !arm_feature(env, ARM_FEATURE_M) &&
-        !arm_feature(env, ARM_FEATURE_MPU)) {
+        !arm_feature(env, ARM_FEATURE_PMSA)) {
         /* v7VMSA drops support for the old ARMv5 tiny pages, so we
          * can use 4K pages.
          */
@@ -764,10 +764,10 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
     }
 
     if (!cpu->has_mpu) {
-        unset_feature(env, ARM_FEATURE_MPU);
+        unset_feature(env, ARM_FEATURE_PMSA);
     }
 
-    if (arm_feature(env, ARM_FEATURE_MPU) &&
+    if (arm_feature(env, ARM_FEATURE_PMSA) &&
         arm_feature(env, ARM_FEATURE_V7)) {
         uint32_t nr = cpu->pmsav7_dregion;
 
@@ -867,7 +867,7 @@ static void arm946_initfn(Object *obj)
 
     cpu->dtb_compatible = "arm,arm946";
     set_feature(&cpu->env, ARM_FEATURE_V5);
-    set_feature(&cpu->env, ARM_FEATURE_MPU);
+    set_feature(&cpu->env, ARM_FEATURE_PMSA);
     set_feature(&cpu->env, ARM_FEATURE_DUMMY_C15_REGS);
     cpu->midr = 0x41059461;
     cpu->ctr = 0x0f004006;
@@ -1079,7 +1079,7 @@ static void cortex_r5_initfn(Object *obj)
     set_feature(&cpu->env, ARM_FEATURE_THUMB_DIV);
     set_feature(&cpu->env, ARM_FEATURE_ARM_DIV);
     set_feature(&cpu->env, ARM_FEATURE_V7MP);
-    set_feature(&cpu->env, ARM_FEATURE_MPU);
+    set_feature(&cpu->env, ARM_FEATURE_PMSA);
     cpu->midr = 0x411fc153; /* r1p3 */
     cpu->id_pfr0 = 0x0131;
     cpu->id_pfr1 = 0x001;