[RFC PATCH 32/40] target/arm: Move "midr" to class property

[Richard Henderson <richard.henderson@linaro.org>]

With the movement of the property, we can remove the field
from the cpu entirely, using only the class.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu.h      |  1 -
 hw/arm/xilinx_zynq.c  |  9 ++++++---
 hw/intc/armv7m_nvic.c |  2 +-
 target/arm/cpu.c      | 18 ++++++++++++++++--
 target/arm/helper.c   | 14 ++++++++------
 5 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 4b47a420d5..f2dceae0e7 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -956,7 +956,6 @@ struct ArchCPU {
      * field by reading the value from the KVM vCPU.
      */
     ARMISARegisters isar;
-    uint64_t midr;
     uint32_t revidr;
     uint32_t reset_fpsid;
     uint64_t ctr;
diff --git a/hw/arm/xilinx_zynq.c b/hw/arm/xilinx_zynq.c
index 3190cc0b8d..3e5b4f4483 100644
--- a/hw/arm/xilinx_zynq.c
+++ b/hw/arm/xilinx_zynq.c
@@ -177,6 +177,7 @@ static inline int zynq_init_spi_flashes(uint32_t base_addr, qemu_irq irq,
 static void zynq_init(MachineState *machine)
 {
     ZynqMachineState *zynq_machine = ZYNQ_MACHINE(machine);
+    ObjectClass *cpu_class;
     ARMCPU *cpu;
     MemoryRegion *address_space_mem = get_system_memory();
     MemoryRegion *ocm_ram = g_new(MemoryRegion, 1);
@@ -191,7 +192,11 @@ static void zynq_init(MachineState *machine)
         exit(EXIT_FAILURE);
     }
 
-    cpu = ARM_CPU(object_new(machine->cpu_type));
+    cpu_class = object_class_by_name(machine->cpu_type);
+
+    class_property_set_uint(cpu_class, "midr", ZYNQ_BOARD_MIDR, &error_fatal);
+
+    cpu = ARM_CPU(object_new_with_class(cpu_class));
 
     /* By default A9 CPUs have EL3 enabled.  This board does not
      * currently support EL3 so the CPU EL3 property is disabled before
@@ -201,8 +206,6 @@ static void zynq_init(MachineState *machine)
         object_property_set_bool(OBJECT(cpu), "has_el3", false, &error_fatal);
     }
 
-    object_property_set_int(OBJECT(cpu), "midr", ZYNQ_BOARD_MIDR,
-                            &error_fatal);
     object_property_set_int(OBJECT(cpu), "reset-cbar", MPCORE_PERIPHBASE,
                             &error_fatal);
     qdev_realize(DEVICE(cpu), NULL, &error_fatal);
diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
index 1f7763964c..92f754a74f 100644
--- a/hw/intc/armv7m_nvic.c
+++ b/hw/intc/armv7m_nvic.c
@@ -1039,7 +1039,7 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset, MemTxAttrs attrs)
         }
         return cpu->revidr;
     case 0xd00: /* CPUID Base.  */
-        return cpu->midr;
+        return ARM_CPU_GET_CLASS(cpu)->midr;
     case 0xd04: /* Interrupt Control State (ICSR) */
         /* VECTACTIVE */
         val = cpu->env.v7m.exception;
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 22a6ccaece..7d68c50d7c 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -1209,7 +1209,6 @@ static void arm_cpu_initfn(Object *obj)
     cpu->env.features = acc->features;
     cpu->isar = acc->isar;
 
-    cpu->midr = acc->midr;
     cpu->ctr = acc->ctr;
     cpu->pmceid0 = acc->pmceid0;
     cpu->pmceid1 = acc->pmceid1;
@@ -2120,7 +2119,6 @@ static void cpu_arm_get_mp_affinity(Object *obj, Visitor *v, const char *name,
 }
 
 static Property arm_cpu_properties[] = {
-    DEFINE_PROP_UINT64("midr", ARMCPU, midr, 0),
     DEFINE_PROP_INT32("node-id", ARMCPU, node_id, CPU_UNSET_NUMA_NODE_ID),
     DEFINE_PROP_INT32("core-count", ARMCPU, core_count, -1),
     DEFINE_PROP_END_OF_LIST()
@@ -2173,6 +2171,17 @@ static const struct TCGCPUOps arm_tcg_ops = {
 };
 #endif /* CONFIG_TCG */
 
+static bool arm_class_prop_uint64_ofs(ObjectClass *oc, Visitor *v,
+                                      const char *name, void *opaque,
+                                      Error **errp)
+{
+    ARMCPUClass *acc = ARM_CPU_CLASS(oc);
+    uintptr_t ofs = (uintptr_t)opaque;
+    uint64_t *ptr = (void *)acc + ofs;
+
+    return visit_type_uint64(v, name, ptr, errp);
+}
+
 static void arm_cpu_class_init(ObjectClass *oc, void *data)
 {
     ARMCPUClass *acc = ARM_CPU_CLASS(oc);
@@ -2220,6 +2229,11 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data)
      */
     acc->dtb_compatible = "qemu,unknown";
     acc->kvm_target = QEMU_KVM_ARM_TARGET_NONE;
+
+    class_property_add(oc, "midr", "uint64", NULL,
+                       arm_class_prop_uint64_ofs,
+                       arm_class_prop_uint64_ofs,
+                       (void *)(uintptr_t)offsetof(ARMCPUClass, midr));
 }
 
 static void arm_cpu_leaf_class_init(ObjectClass *oc, void *data)
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 43756e130a..d18200ed16 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -7443,6 +7443,8 @@ void register_cp_regs_for_features(ARMCPU *cpu)
 {
     /* Register all the coprocessor registers based on feature bits */
     CPUARMState *env = &cpu->env;
+    ARMCPUClass *acc = ARM_CPU_GET_CLASS(cpu);
+
     if (arm_feature(env, ARM_FEATURE_M)) {
         /* M profile has no coprocessor registers */
         return;
@@ -7926,12 +7928,12 @@ void register_cp_regs_for_features(ARMCPU *cpu)
             { .name = "VPIDR", .state = ARM_CP_STATE_AA32,
               .cp = 15, .opc1 = 4, .crn = 0, .crm = 0, .opc2 = 0,
               .access = PL2_RW, .accessfn = access_el3_aa32ns,
-              .resetvalue = cpu->midr,
+              .resetvalue = acc->midr,
               .type = ARM_CP_ALIAS | ARM_CP_EL3_NO_EL2_C_NZ,
               .fieldoffset = offsetoflow32(CPUARMState, cp15.vpidr_el2) },
             { .name = "VPIDR_EL2", .state = ARM_CP_STATE_AA64,
               .opc0 = 3, .opc1 = 4, .crn = 0, .crm = 0, .opc2 = 0,
-              .access = PL2_RW, .resetvalue = cpu->midr,
+              .access = PL2_RW, .resetvalue = acc->midr,
               .type = ARM_CP_EL3_NO_EL2_C_NZ,
               .fieldoffset = offsetof(CPUARMState, cp15.vpidr_el2) },
             { .name = "VMPIDR", .state = ARM_CP_STATE_AA32,
@@ -8106,7 +8108,7 @@ void register_cp_regs_for_features(ARMCPU *cpu)
              */
             { .name = "MIDR",
               .cp = 15, .crn = 0, .crm = 0, .opc1 = 0, .opc2 = CP_ANY,
-              .access = PL1_R, .resetvalue = cpu->midr,
+              .access = PL1_R, .resetvalue = acc->midr,
               .writefn = arm_cp_write_ignore, .raw_writefn = raw_write,
               .readfn = midr_read,
               .fieldoffset = offsetof(CPUARMState, cp15.c0_cpuid),
@@ -8131,16 +8133,16 @@ void register_cp_regs_for_features(ARMCPU *cpu)
         ARMCPRegInfo id_v8_midr_cp_reginfo[] = {
             { .name = "MIDR_EL1", .state = ARM_CP_STATE_BOTH,
               .opc0 = 3, .opc1 = 0, .crn = 0, .crm = 0, .opc2 = 0,
-              .access = PL1_R, .type = ARM_CP_NO_RAW, .resetvalue = cpu->midr,
+              .access = PL1_R, .type = ARM_CP_NO_RAW, .resetvalue = acc->midr,
               .fieldoffset = offsetof(CPUARMState, cp15.c0_cpuid),
               .readfn = midr_read },
             /* crn = 0 op1 = 0 crm = 0 op2 = 4,7 : AArch32 aliases of MIDR */
             { .name = "MIDR", .type = ARM_CP_ALIAS | ARM_CP_CONST,
               .cp = 15, .crn = 0, .crm = 0, .opc1 = 0, .opc2 = 4,
-              .access = PL1_R, .resetvalue = cpu->midr },
+              .access = PL1_R, .resetvalue = acc->midr },
             { .name = "MIDR", .type = ARM_CP_ALIAS | ARM_CP_CONST,
               .cp = 15, .crn = 0, .crm = 0, .opc1 = 0, .opc2 = 7,
-              .access = PL1_R, .resetvalue = cpu->midr },
+              .access = PL1_R, .resetvalue = acc->midr },
             { .name = "REVIDR_EL1", .state = ARM_CP_STATE_BOTH,
               .opc0 = 3, .opc1 = 0, .crn = 0, .crm = 0, .opc2 = 6,
               .access = PL1_R,
-- 
2.34.1