[Qemu-devel] [PATCH target-arm v3 1/7] target-arm/helper.c: define MPUIR register

[Peter Crosthwaite]

Define the MPUIR register for MPU supporting ARMv6 and onwards.
Currently we only support unified MPU.

The size of the unified MPU is defined via the number of "dregions".
So just a single config is added to specify this size. (When split MPU
is implemented we will add an extra iregions config).

Signed-off-by: Peter Crosthwaite <address@hidden>
---
changed since v2 (PMM review):
Fix commit message wording issues.
change assertion to realize error.
allow 0 regions.
raise error of >255 memory regions.
changed since v1:
Add #regions configuration
conditionalize MPUIR existence

 target-arm/cpu-qom.h |  2 ++
 target-arm/cpu.c     | 18 ++++++++++++++++++
 target-arm/helper.c  | 10 ++++++++++
 3 files changed, 30 insertions(+)

diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
index 072aa9b..3cbc4a0 100644
--- a/target-arm/cpu-qom.h
+++ b/target-arm/cpu-qom.h
@@ -105,6 +105,8 @@ typedef struct ARMCPU {
 
     /* CPU has memory protection unit */
     bool has_mpu;
+    /* PMSAv7 MPU number of supported regions */
+    uint32_t pmsav7_dregion;
 
     /* PSCI conduit used to invoke PSCI methods
      * 0 - disabled, 1 - smc, 2 - hvc
diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index 7496983..a3d702f 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -457,6 +457,9 @@ static Property arm_cpu_has_el3_property =
 static Property arm_cpu_has_mpu_property =
             DEFINE_PROP_BOOL("has-mpu", ARMCPU, has_mpu, true);
 
+static Property arm_cpu_pmsav7_dregion_property =
+            DEFINE_PROP_UINT32("pmsav7-dregion", ARMCPU, pmsav7_dregion, 16);
+
 static void arm_cpu_post_init(Object *obj)
 {
     ARMCPU *cpu = ARM_CPU(obj);
@@ -488,6 +491,11 @@ static void arm_cpu_post_init(Object *obj)
     if (arm_feature(&cpu->env, ARM_FEATURE_MPU)) {
         qdev_property_add_static(DEVICE(obj), &arm_cpu_has_mpu_property,
                                  &error_abort);
+        if (arm_feature(&cpu->env, ARM_FEATURE_V7)) {
+            qdev_property_add_static(DEVICE(obj),
+                                     &arm_cpu_pmsav7_dregion_property,
+                                     &error_abort);
+        }
     }
 
 }
@@ -580,6 +588,16 @@ static void arm_cpu_realizefn(DeviceState *dev, Error 
**errp)
         unset_feature(env, ARM_FEATURE_MPU);
     }
 
+    if (arm_feature(env, ARM_FEATURE_MPU) &&
+        arm_feature(env, ARM_FEATURE_V7)) {
+        uint32_t nr = cpu->pmsav7_dregion;
+
+        if (nr > 0xff) {
+            error_setg(errp, "PMSAv7 MPU #regions invalid %" PRIu32 "\n", nr);
+            return;
+        }
+    }
+
     register_cp_regs_for_features(cpu);
     arm_cpu_register_gdb_regs_for_features(cpu);
 
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 00509b1..685f972 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -3465,6 +3465,13 @@ void register_cp_regs_for_features(ARMCPU *cpu)
               .cp = 15, .crn = 0, .crm = 0, .opc1 = 0, .opc2 = 3,
               .access = PL1_R, .type = ARM_CP_CONST, .resetvalue = 0,
         };
+        /* MPUIR is specific to PMSA V6+ */
+        ARMCPRegInfo id_mpuir_reginfo = {
+              .name = "MPUIR",
+              .cp = 15, .crn = 0, .crm = 0, .opc1 = 0, .opc2 = 4,
+              .access = PL1_R, .type = ARM_CP_CONST,
+              .resetvalue = cpu->pmsav7_dregion << 8
+        };
         ARMCPRegInfo crn0_wi_reginfo = {
             .name = "CRN0_WI", .cp = 15, .crn = 0, .crm = CP_ANY,
             .opc1 = CP_ANY, .opc2 = CP_ANY, .access = PL1_W,
@@ -3487,6 +3494,7 @@ void register_cp_regs_for_features(ARMCPU *cpu)
                 r->access = PL1_RW;
             }
             id_tlbtr_reginfo.access = PL1_RW;
+            id_tlbtr_reginfo.access = PL1_RW;
         }
         if (arm_feature(env, ARM_FEATURE_V8)) {
             define_arm_cp_regs(cpu, id_v8_midr_cp_reginfo);
@@ -3496,6 +3504,8 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         define_arm_cp_regs(cpu, id_cp_reginfo);
         if (!arm_feature(env, ARM_FEATURE_MPU)) {
             define_one_arm_cp_reg(cpu, &id_tlbtr_reginfo);
+        } else if (arm_feature(env, ARM_FEATURE_V7)) {
+            define_one_arm_cp_reg(cpu, &id_mpuir_reginfo);
         }
     }
 
-- 
2.4.3.3.g905f831