[Qemu-devel] [PATCH qom-next v2 0/5] QOM Super class access

[Qemu-devel] [PATCH qom-next v2 0/5] QOM Super class access

[peter.crosthwaite]

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

This series enables QOM super class access and demostrates some usages.
Replaces the save->override->call via FooClass technique, to reduce
some of the boiler plate in recently fully QOMified devices.

Applied the change to ARM CPU, MB CPU and some of Andreas's recently
QOMified i386 devices, all which have the save->override->call issue.
ARMCPU I've done a brief test on and seems to work.

ARM CPU was particularly difficult, as it has 3 layers of heirachy,
where a non-concrete class (TYPE_ARM_CPU) need to super class itself
(to TYPE_CPU). This sees the need for super-classers to specify their
expected base class level. See patches for illustration.

The main future work to the series is to apply the change pattern to
the reset of the tree

changed since V1:
Simplified to use object_class_get_parent_by_type (suggest by Hu Tao)


Peter Crosthwaite (5):
  target-arm/cpu.c: delete un-needed instance/class sizes
  qom/object: Add object_class_get_parent_by_name
  target-arm: Use parent classes for reset + realize
  target-microblaze: Use parent class for reset + realize
  i8254: Use parent class for realize

 hw/i386/kvm/i8254.c         | 18 +++---------------
 hw/timer/i8254.c            | 17 +++--------------
 include/qom/object.h        |  9 +++++++++
 qom/object.c                |  5 +++++
 target-arm/cpu-qom.h        | 20 --------------------
 target-arm/cpu.c            | 18 +++++++-----------
 target-microblaze/cpu-qom.h | 20 --------------------
 target-microblaze/cpu.c     | 16 ++++++----------
 8 files changed, 33 insertions(+), 90 deletions(-)

-- 
1.8.3.rc1.44.gb387c77.dirty

[Qemu-devel] [PATCH qom-next v2 1/5] target-arm/cpu.c: delete un-needed instance/class sizes

[peter.crosthwaite]

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

QOM automatically inherits class and instance size from the parent
class. No need to redefine as the same value as the parent.

CC: qemu-trivial@nongnu.org

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
---

 target-arm/cpu.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index 1bc227e..ed53df8 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -823,9 +823,7 @@ static void cpu_register(const ARMCPUInfo *info)
 {
     TypeInfo type_info = {
         .parent = TYPE_ARM_CPU,
-        .instance_size = sizeof(ARMCPU),
         .instance_init = info->initfn,
-        .class_size = sizeof(ARMCPUClass),
         .class_init = info->class_init,
     };
 
-- 
1.8.3.rc1.44.gb387c77.dirty

[Qemu-devel] [PATCH qom-next v2 2/5] qom/object: Add object_class_get_parent_by_name

[peter.crosthwaite]

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

Function for looking up a class by name then getting its parent.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
---

 include/qom/object.h | 9 +++++++++
 qom/object.c         | 5 +++++
 2 files changed, 14 insertions(+)

diff --git a/include/qom/object.h b/include/qom/object.h
index 23fc048..f5ce2e8 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -706,6 +706,15 @@ ObjectClass *object_class_dynamic_cast(ObjectClass *klass,
 ObjectClass *object_class_get_parent(ObjectClass *klass);
 
 /**
+ * object_class_get_parent_by_name:
+ * Lookup a class by name and get its parent.
+ * @typename: The class to lookup and obtain the parent for.
+ *
+ * Returns: The parent for @typename's class or %NULL if none.
+ */
+ObjectClass *object_class_get_parent_by_name(const char *typename);
+
+/**
  * object_class_get_name:
  * @klass: The class to obtain the QOM typename for.
  *
diff --git a/qom/object.c b/qom/object.c
index cbd7e86..4a3197d 100644
--- a/qom/object.c
+++ b/qom/object.c
@@ -608,6 +608,11 @@ ObjectClass *object_class_get_parent(ObjectClass *class)
     return type->class;
 }
 
+ObjectClass *object_class_get_parent_by_name(const char *typename)
+{
+    return object_class_get_parent(object_class_by_name(typename));
+}
+
 typedef struct OCFData
 {
     void (*fn)(ObjectClass *klass, void *opaque);
-- 
1.8.3.rc1.44.gb387c77.dirty

[Qemu-devel] [PATCH qom-next v2 3/5] target-arm: Use parent classes for reset + realize

[peter.crosthwaite]

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

ARMCPUClass is only needed for parent-class abstract function access.
Just use parent classes for reset and realize access and remove
ARMCPUClass completely.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
---

 target-arm/cpu-qom.h | 20 --------------------
 target-arm/cpu.c     | 16 +++++++---------
 2 files changed, 7 insertions(+), 29 deletions(-)

diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
index ef6261f..bdad93a 100644
--- a/target-arm/cpu-qom.h
+++ b/target-arm/cpu-qom.h
@@ -24,28 +24,8 @@
 
 #define TYPE_ARM_CPU "arm-cpu"
 
-#define ARM_CPU_CLASS(klass) \
-    OBJECT_CLASS_CHECK(ARMCPUClass, (klass), TYPE_ARM_CPU)
 #define ARM_CPU(obj) \
     OBJECT_CHECK(ARMCPU, (obj), TYPE_ARM_CPU)
-#define ARM_CPU_GET_CLASS(obj) \
-    OBJECT_GET_CLASS(ARMCPUClass, (obj), TYPE_ARM_CPU)
-
-/**
- * ARMCPUClass:
- * @parent_realize: The parent class' realize handler.
- * @parent_reset: The parent class' reset handler.
- *
- * An ARM CPU model.
- */
-typedef struct ARMCPUClass {
-    /*< private >*/
-    CPUClass parent_class;
-    /*< public >*/
-
-    DeviceRealize parent_realize;
-    void (*parent_reset)(CPUState *cpu);
-} ARMCPUClass;
 
 /**
  * ARMCPU:
diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index ed53df8..ad5ec7b 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -60,7 +60,8 @@ static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
 static void arm_cpu_reset(CPUState *s)
 {
     ARMCPU *cpu = ARM_CPU(s);
-    ARMCPUClass *acc = ARM_CPU_GET_CLASS(cpu);
+    CPUClass *cc_parent =
+            CPU_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
     CPUARMState *env = &cpu->env;
 
     if (qemu_loglevel_mask(CPU_LOG_RESET)) {
@@ -68,7 +69,7 @@ static void arm_cpu_reset(CPUState *s)
         log_cpu_state(env, 0);
     }
 
-    acc->parent_reset(s);
+    cc_parent->reset(s);
 
     memset(env, 0, offsetof(CPUARMState, breakpoints));
     g_hash_table_foreach(cpu->cp_regs, cp_reg_reset, cpu);
@@ -158,7 +159,8 @@ static void arm_cpu_finalizefn(Object *obj)
 static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
 {
     ARMCPU *cpu = ARM_CPU(dev);
-    ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
+    DeviceClass *dc_parent =
+            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
     CPUARMState *env = &cpu->env;
 
     /* Some features automatically imply others: */
@@ -209,7 +211,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
 
     cpu_reset(CPU(cpu));
 
-    acc->parent_realize(dev, errp);
+    dc_parent->realize(dev, errp);
 }
 
 /* CPU models */
@@ -803,14 +805,11 @@ static const ARMCPUInfo arm_cpus[] = {
 
 static void arm_cpu_class_init(ObjectClass *oc, void *data)
 {
-    ARMCPUClass *acc = ARM_CPU_CLASS(oc);
-    CPUClass *cc = CPU_CLASS(acc);
+    CPUClass *cc = CPU_CLASS(oc);
     DeviceClass *dc = DEVICE_CLASS(oc);
 
-    acc->parent_realize = dc->realize;
     dc->realize = arm_cpu_realizefn;
 
-    acc->parent_reset = cc->reset;
     cc->reset = arm_cpu_reset;
 
     cc->class_by_name = arm_cpu_class_by_name;
@@ -839,7 +838,6 @@ static const TypeInfo arm_cpu_type_info = {
     .instance_init = arm_cpu_initfn,
     .instance_finalize = arm_cpu_finalizefn,
     .abstract = true,
-    .class_size = sizeof(ARMCPUClass),
     .class_init = arm_cpu_class_init,
 };
 
-- 
1.8.3.rc1.44.gb387c77.dirty

[Qemu-devel] [PATCH qom-next v2 4/5] target-microblaze: Use parent class for reset + realize

[peter.crosthwaite]

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

MicroblazeCPUClass is only needed for parent-class abstract function
access. Just use parent classes for reset and realize access and remove
MicroblazeCPUClass completely.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
---

 target-microblaze/cpu-qom.h | 20 --------------------
 target-microblaze/cpu.c     | 16 ++++++----------
 2 files changed, 6 insertions(+), 30 deletions(-)

diff --git a/target-microblaze/cpu-qom.h b/target-microblaze/cpu-qom.h
index 3e9c206..f47259b 100644
--- a/target-microblaze/cpu-qom.h
+++ b/target-microblaze/cpu-qom.h
@@ -24,28 +24,8 @@
 
 #define TYPE_MICROBLAZE_CPU "microblaze-cpu"
 
-#define MICROBLAZE_CPU_CLASS(klass) \
-    OBJECT_CLASS_CHECK(MicroBlazeCPUClass, (klass), TYPE_MICROBLAZE_CPU)
 #define MICROBLAZE_CPU(obj) \
     OBJECT_CHECK(MicroBlazeCPU, (obj), TYPE_MICROBLAZE_CPU)
-#define MICROBLAZE_CPU_GET_CLASS(obj) \
-    OBJECT_GET_CLASS(MicroBlazeCPUClass, (obj), TYPE_MICROBLAZE_CPU)
-
-/**
- * MicroBlazeCPUClass:
- * @parent_realize: The parent class' realize handler.
- * @parent_reset: The parent class' reset handler.
- *
- * A MicroBlaze CPU model.
- */
-typedef struct MicroBlazeCPUClass {
-    /*< private >*/
-    CPUClass parent_class;
-    /*< public >*/
-
-    DeviceRealize parent_realize;
-    void (*parent_reset)(CPUState *cpu);
-} MicroBlazeCPUClass;
 
 /**
  * MicroBlazeCPU:
diff --git a/target-microblaze/cpu.c b/target-microblaze/cpu.c
index a0fcdf4..e8d76b9 100644
--- a/target-microblaze/cpu.c
+++ b/target-microblaze/cpu.c
@@ -25,12 +25,12 @@
 #include "hw/qdev-properties.h"
 #include "migration/vmstate.h"
 
-
 /* CPUClass::reset() */
 static void mb_cpu_reset(CPUState *s)
 {
     MicroBlazeCPU *cpu = MICROBLAZE_CPU(s);
-    MicroBlazeCPUClass *mcc = MICROBLAZE_CPU_GET_CLASS(cpu);
+    CPUClass *cc_parent =
+            CPU_CLASS(object_class_get_parent_by_name(TYPE_MICROBLAZE_CPU));
     CPUMBState *env = &cpu->env;
 
     if (qemu_loglevel_mask(CPU_LOG_RESET)) {
@@ -38,7 +38,7 @@ static void mb_cpu_reset(CPUState *s)
         log_cpu_state(env, 0);
     }
 
-    mcc->parent_reset(s);
+    cc_parent->reset(s);
 
     memset(env, 0, offsetof(CPUMBState, breakpoints));
     env->res_addr = RES_ADDR_NONE;
@@ -89,11 +89,11 @@ static void mb_cpu_reset(CPUState *s)
 static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
 {
     MicroBlazeCPU *cpu = MICROBLAZE_CPU(dev);
-    MicroBlazeCPUClass *mcc = MICROBLAZE_CPU_GET_CLASS(dev);
-
+    DeviceClass *dc_parent =
+            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_MICROBLAZE_CPU));
     cpu_reset(CPU(cpu));
 
-    mcc->parent_realize(dev, errp);
+    dc_parent->realize(dev, errp);
 }
 
 static void mb_cpu_initfn(Object *obj)
@@ -128,12 +128,9 @@ static void mb_cpu_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
     CPUClass *cc = CPU_CLASS(oc);
-    MicroBlazeCPUClass *mcc = MICROBLAZE_CPU_CLASS(oc);
 
-    mcc->parent_realize = dc->realize;
     dc->realize = mb_cpu_realizefn;
 
-    mcc->parent_reset = cc->reset;
     cc->reset = mb_cpu_reset;
 
     cc->do_interrupt = mb_cpu_do_interrupt;
@@ -148,7 +145,6 @@ static const TypeInfo mb_cpu_type_info = {
     .parent = TYPE_CPU,
     .instance_size = sizeof(MicroBlazeCPU),
     .instance_init = mb_cpu_initfn,
-    .class_size = sizeof(MicroBlazeCPUClass),
     .class_init = mb_cpu_class_init,
 };
 
-- 
1.8.3.rc1.44.gb387c77.dirty

[Qemu-devel] [PATCH qom-next v2 5/5] i8254: Use parent class for realize

[peter.crosthwaite]

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

[KVM]PITClass is only needed for parent-class realize function access.
Just use parent classes for realize access and remove [KVM]PITClass
completely.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
---

 hw/i386/kvm/i8254.c | 18 +++---------------
 hw/timer/i8254.c    | 17 +++--------------
 2 files changed, 6 insertions(+), 29 deletions(-)

diff --git a/hw/i386/kvm/i8254.c b/hw/i386/kvm/i8254.c
index c1f4094..36d2e21 100644
--- a/hw/i386/kvm/i8254.c
+++ b/hw/i386/kvm/i8254.c
@@ -33,10 +33,6 @@
 #define CALIBRATION_ROUNDS   3
 
 #define KVM_PIT(obj) OBJECT_CHECK(KVMPITState, (obj), TYPE_KVM_I8254)
-#define KVM_PIT_CLASS(class) \
-    OBJECT_CLASS_CHECK(KVMPITClass, (class), TYPE_KVM_I8254)
-#define KVM_PIT_GET_CLASS(obj) \
-    OBJECT_GET_CLASS(KVMPITClass, (obj), TYPE_KVM_I8254)
 
 typedef struct KVMPITState {
     PITCommonState parent_obj;
@@ -46,12 +42,6 @@ typedef struct KVMPITState {
     int64_t kernel_clock_offset;
 } KVMPITState;
 
-typedef struct KVMPITClass {
-    PITCommonClass parent_class;
-
-    DeviceRealize parent_realize;
-} KVMPITClass;
-
 static int64_t abs64(int64_t v)
 {
     return v < 0 ? -v : v;
@@ -250,7 +240,8 @@ static void kvm_pit_vm_state_change(void *opaque, int running,
 static void kvm_pit_realizefn(DeviceState *dev, Error **errp)
 {
     PITCommonState *pit = PIT_COMMON(dev);
-    KVMPITClass *kpc = KVM_PIT_GET_CLASS(dev);
+    DeviceClass *dc_parent =
+            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_KVM_I8254));
     KVMPITState *s = KVM_PIT(pit);
     struct kvm_pit_config config = {
         .flags = 0,
@@ -294,7 +285,7 @@ static void kvm_pit_realizefn(DeviceState *dev, Error **errp)
 
     qemu_add_vm_change_state_handler(kvm_pit_vm_state_change, s);
 
-    kpc->parent_realize(dev, errp);
+    dc_parent->realize(dev, errp);
 }
 
 static Property kvm_pit_properties[] = {
@@ -306,11 +297,9 @@ static Property kvm_pit_properties[] = {
 
 static void kvm_pit_class_init(ObjectClass *klass, void *data)
 {
-    KVMPITClass *kpc = KVM_PIT_CLASS(klass);
     PITCommonClass *k = PIT_COMMON_CLASS(klass);
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    kpc->parent_realize = dc->realize;
     dc->realize = kvm_pit_realizefn;
     k->set_channel_gate = kvm_pit_set_gate;
     k->get_channel_info = kvm_pit_get_channel_info;
@@ -325,7 +314,6 @@ static const TypeInfo kvm_pit_info = {
     .parent        = TYPE_PIT_COMMON,
     .instance_size = sizeof(KVMPITState),
     .class_init = kvm_pit_class_init,
-    .class_size = sizeof(KVMPITClass),
 };
 
 static void kvm_pit_register(void)
diff --git a/hw/timer/i8254.c b/hw/timer/i8254.c
index cd52140..8db8b34 100644
--- a/hw/timer/i8254.c
+++ b/hw/timer/i8254.c
@@ -35,15 +35,6 @@
 #define RW_STATE_WORD0 3
 #define RW_STATE_WORD1 4
 
-#define PIT_CLASS(class) OBJECT_CLASS_CHECK(PITClass, (class), TYPE_I8254)
-#define PIT_GET_CLASS(obj) OBJECT_GET_CLASS(PITClass, (obj), TYPE_I8254)
-
-typedef struct PITClass {
-    PITCommonClass parent_class;
-
-    DeviceRealize parent_realize;
-} PITClass;
-
 static void pit_irq_timer_update(PITChannelState *s, int64_t current_time);
 
 static int pit_get_count(PITChannelState *s)
@@ -325,7 +316,8 @@ static void pit_post_load(PITCommonState *s)
 static void pit_realizefn(DeviceState *dev, Error **err)
 {
     PITCommonState *pit = PIT_COMMON(dev);
-    PITClass *pc = PIT_GET_CLASS(dev);
+    DeviceClass *dc_parent =
+            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_I8254));
     PITChannelState *s;
 
     s = &pit->channels[0];
@@ -338,7 +330,7 @@ static void pit_realizefn(DeviceState *dev, Error **err)
 
     qdev_init_gpio_in(dev, pit_irq_control, 1);
 
-    pc->parent_realize(dev, err);
+    dc_parent->realize(dev, err);
 }
 
 static Property pit_properties[] = {
@@ -348,11 +340,9 @@ static Property pit_properties[] = {
 
 static void pit_class_initfn(ObjectClass *klass, void *data)
 {
-    PITClass *pc = PIT_CLASS(klass);
     PITCommonClass *k = PIT_COMMON_CLASS(klass);
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    pc->parent_realize = dc->realize;
     dc->realize = pit_realizefn;
     k->set_channel_gate = pit_set_channel_gate;
     k->get_channel_info = pit_get_channel_info_common;
@@ -366,7 +356,6 @@ static const TypeInfo pit_info = {
     .parent        = TYPE_PIT_COMMON,
     .instance_size = sizeof(PITCommonState),
     .class_init    = pit_class_initfn,
-    .class_size    = sizeof(PITClass),
 };
 
 static void pit_register_types(void)
-- 
1.8.3.rc1.44.gb387c77.dirty

Re: [Qemu-devel] [PATCH qom-next v2 1/5] target-arm/cpu.c: delete un-needed instance/class sizes

[Andreas Färber]

Am 11.07.2013 03:45, schrieb peter.crosthwaite@xilinx.com:
> From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> 
> QOM automatically inherits class and instance size from the parent
> class. No need to redefine as the same value as the parent.

Quoting my original comment:
"It would be fair to mention since which commit because that was
originally not the case."

http://git.qemu.org/?p=qemu.git;a=commit;h=aca59af612840772f18598363b65a25bf02bb569

E.g., "By now, QOM automatically..." or "Since commit ..."

> 
> CC: qemu-trivial@nongnu.org

We have an active ARM maintainer, so no reason to involve qemu-trivial
here by our definition. Possibly that would've required Cc: anyway? Not
actually CC'ed.

> 
> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

Still:

Reviewed-by: Andreas Färber <afaerber@suse.de>

PMM, do you want to pick this one up for target-arm.next? The rest
depends on central infrastructure under discussion. Suggest renaming to
"target-arm: Delete un-needed instance/class sizes for ARMCPU
subclasses" for simplicity and so that it aligns nicely with others.

Regards,
Andreas

> ---
> 
>  target-arm/cpu.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> index 1bc227e..ed53df8 100644
> --- a/target-arm/cpu.c
> +++ b/target-arm/cpu.c
> @@ -823,9 +823,7 @@ static void cpu_register(const ARMCPUInfo *info)
>  {
>      TypeInfo type_info = {
>          .parent = TYPE_ARM_CPU,
> -        .instance_size = sizeof(ARMCPU),
>          .instance_init = info->initfn,
> -        .class_size = sizeof(ARMCPUClass),
>          .class_init = info->class_init,
>      };
>  

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] [PATCH qom-next v2 1/5] target-arm/cpu.c: delete un-needed instance/class sizes

[Peter Maydell]

On 11 July 2013 09:07, Andreas Färber <afaerber@suse.de> wrote:
> PMM, do you want to pick this one up for target-arm.next? The rest
> depends on central infrastructure under discussion. Suggest renaming to
> "target-arm: Delete un-needed instance/class sizes for ARMCPU
> subclasses" for simplicity and so that it aligns nicely with others.

I really prefer not to pick up single patches from a series,
it is awkward. A patch series should be a coherent set which
is picked up by whichever subtree it is overall most fitted to.
(Similarly, cc'ing qemu-trivial on one or two patches out of a
set doesn't make much sense.)

thanks
-- PMM

Re: [Qemu-devel] [PATCH qom-next v2 3/5] target-arm: Use parent classes for reset + realize

[Igor Mammedov]

On Thu, 11 Jul 2013 11:47:16 +1000
peter.crosthwaite@xilinx.com wrote:

> From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> 
> ARMCPUClass is only needed for parent-class abstract function access.
> Just use parent classes for reset and realize access and remove
> ARMCPUClass completely.
> 
> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> ---
> 
>  target-arm/cpu-qom.h | 20 --------------------
>  target-arm/cpu.c     | 16 +++++++---------
>  2 files changed, 7 insertions(+), 29 deletions(-)
> 
> diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
> index ef6261f..bdad93a 100644
> --- a/target-arm/cpu-qom.h
> +++ b/target-arm/cpu-qom.h
> @@ -24,28 +24,8 @@
>  
>  #define TYPE_ARM_CPU "arm-cpu"
>  
> -#define ARM_CPU_CLASS(klass) \
> -    OBJECT_CLASS_CHECK(ARMCPUClass, (klass), TYPE_ARM_CPU)
>  #define ARM_CPU(obj) \
>      OBJECT_CHECK(ARMCPU, (obj), TYPE_ARM_CPU)
> -#define ARM_CPU_GET_CLASS(obj) \
> -    OBJECT_GET_CLASS(ARMCPUClass, (obj), TYPE_ARM_CPU)
> -
> -/**
> - * ARMCPUClass:
> - * @parent_realize: The parent class' realize handler.
> - * @parent_reset: The parent class' reset handler.
> - *
> - * An ARM CPU model.
> - */
> -typedef struct ARMCPUClass {
> -    /*< private >*/
> -    CPUClass parent_class;
> -    /*< public >*/
> -
> -    DeviceRealize parent_realize;
> -    void (*parent_reset)(CPUState *cpu);
> -} ARMCPUClass;
>  
>  /**
>   * ARMCPU:
> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> index ed53df8..ad5ec7b 100644
> --- a/target-arm/cpu.c
> +++ b/target-arm/cpu.c
> @@ -60,7 +60,8 @@ static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
>  static void arm_cpu_reset(CPUState *s)
>  {
>      ARMCPU *cpu = ARM_CPU(s);
> -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(cpu);
> +    CPUClass *cc_parent =
> +            CPU_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
Maybe object_class_get_parent_of_type() would be less confusing?

This usage assumes that parent of TYPE_ARM_CPU is TYPE_CPU and if
another TYPE_X added between them, it might break if TYPE_X doesn't
re-implement this logic in its reset.

Could reset be modeled like DEVICE.instance_init() instead? Then
no explicit access to parent from child would be needed and it
still leaves possibility to override resets if parent->child
propagation order is not desirable for a particular device.

>      CPUARMState *env = &cpu->env;
>  
>      if (qemu_loglevel_mask(CPU_LOG_RESET)) {
> @@ -68,7 +69,7 @@ static void arm_cpu_reset(CPUState *s)
>          log_cpu_state(env, 0);
>      }
>  
> -    acc->parent_reset(s);
> +    cc_parent->reset(s);
>  
>      memset(env, 0, offsetof(CPUARMState, breakpoints));
>      g_hash_table_foreach(cpu->cp_regs, cp_reg_reset, cpu);
> @@ -158,7 +159,8 @@ static void arm_cpu_finalizefn(Object *obj)
>  static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
>  {
>      ARMCPU *cpu = ARM_CPU(dev);
> -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
> +    DeviceClass *dc_parent =
> +            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
>      CPUARMState *env = &cpu->env;
>  
>      /* Some features automatically imply others: */
> @@ -209,7 +211,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
>  
>      cpu_reset(CPU(cpu));
>  
> -    acc->parent_realize(dev, errp);
> +    dc_parent->realize(dev, errp);
>  }
>  
>  /* CPU models */
> @@ -803,14 +805,11 @@ static const ARMCPUInfo arm_cpus[] = {
>  
>  static void arm_cpu_class_init(ObjectClass *oc, void *data)
>  {
> -    ARMCPUClass *acc = ARM_CPU_CLASS(oc);
> -    CPUClass *cc = CPU_CLASS(acc);
> +    CPUClass *cc = CPU_CLASS(oc);
>      DeviceClass *dc = DEVICE_CLASS(oc);
>  
> -    acc->parent_realize = dc->realize;
>      dc->realize = arm_cpu_realizefn;
>  
> -    acc->parent_reset = cc->reset;
>      cc->reset = arm_cpu_reset;
>  
>      cc->class_by_name = arm_cpu_class_by_name;
> @@ -839,7 +838,6 @@ static const TypeInfo arm_cpu_type_info = {
>      .instance_init = arm_cpu_initfn,
>      .instance_finalize = arm_cpu_finalizefn,
>      .abstract = true,
> -    .class_size = sizeof(ARMCPUClass),
>      .class_init = arm_cpu_class_init,
>  };
>  

Re: [Qemu-devel] [PATCH qom-next v2 3/5] target-arm: Use parent classes for reset + realize

[Michael S. Tsirkin]

On Thu, Jul 11, 2013 at 11:47:59AM +0200, Igor Mammedov wrote:
> On Thu, 11 Jul 2013 11:47:16 +1000
> peter.crosthwaite@xilinx.com wrote:
> 
> > From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> > 
> > ARMCPUClass is only needed for parent-class abstract function access.
> > Just use parent classes for reset and realize access and remove
> > ARMCPUClass completely.
> > 
> > Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> > ---
> > 
> >  target-arm/cpu-qom.h | 20 --------------------
> >  target-arm/cpu.c     | 16 +++++++---------
> >  2 files changed, 7 insertions(+), 29 deletions(-)
> > 
> > diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
> > index ef6261f..bdad93a 100644
> > --- a/target-arm/cpu-qom.h
> > +++ b/target-arm/cpu-qom.h
> > @@ -24,28 +24,8 @@
> >  
> >  #define TYPE_ARM_CPU "arm-cpu"
> >  
> > -#define ARM_CPU_CLASS(klass) \
> > -    OBJECT_CLASS_CHECK(ARMCPUClass, (klass), TYPE_ARM_CPU)
> >  #define ARM_CPU(obj) \
> >      OBJECT_CHECK(ARMCPU, (obj), TYPE_ARM_CPU)
> > -#define ARM_CPU_GET_CLASS(obj) \
> > -    OBJECT_GET_CLASS(ARMCPUClass, (obj), TYPE_ARM_CPU)
> > -
> > -/**
> > - * ARMCPUClass:
> > - * @parent_realize: The parent class' realize handler.
> > - * @parent_reset: The parent class' reset handler.
> > - *
> > - * An ARM CPU model.
> > - */
> > -typedef struct ARMCPUClass {
> > -    /*< private >*/
> > -    CPUClass parent_class;
> > -    /*< public >*/
> > -
> > -    DeviceRealize parent_realize;
> > -    void (*parent_reset)(CPUState *cpu);
> > -} ARMCPUClass;
> >  
> >  /**
> >   * ARMCPU:
> > diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> > index ed53df8..ad5ec7b 100644
> > --- a/target-arm/cpu.c
> > +++ b/target-arm/cpu.c
> > @@ -60,7 +60,8 @@ static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
> >  static void arm_cpu_reset(CPUState *s)
> >  {
> >      ARMCPU *cpu = ARM_CPU(s);
> > -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(cpu);
> > +    CPUClass *cc_parent =
> > +            CPU_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
> Maybe object_class_get_parent_of_type() would be less confusing?
> 
> This usage assumes that parent of TYPE_ARM_CPU is TYPE_CPU and if
> another TYPE_X added between them, it might break if TYPE_X doesn't
> re-implement this logic in its reset.

If what's needed is TYPE_CPU, you can just look up the class by name.

> Could reset be modeled like DEVICE.instance_init() instead? Then
> no explicit access to parent from child would be needed and it
> still leaves possibility to override resets if parent->child
> propagation order is not desirable for a particular device.
> 
> >      CPUARMState *env = &cpu->env;
> >  
> >      if (qemu_loglevel_mask(CPU_LOG_RESET)) {
> > @@ -68,7 +69,7 @@ static void arm_cpu_reset(CPUState *s)
> >          log_cpu_state(env, 0);
> >      }
> >  
> > -    acc->parent_reset(s);
> > +    cc_parent->reset(s);
> >  
> >      memset(env, 0, offsetof(CPUARMState, breakpoints));
> >      g_hash_table_foreach(cpu->cp_regs, cp_reg_reset, cpu);
> > @@ -158,7 +159,8 @@ static void arm_cpu_finalizefn(Object *obj)
> >  static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
> >  {
> >      ARMCPU *cpu = ARM_CPU(dev);
> > -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
> > +    DeviceClass *dc_parent =
> > +            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
> >      CPUARMState *env = &cpu->env;
> >  
> >      /* Some features automatically imply others: */
> > @@ -209,7 +211,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
> >  
> >      cpu_reset(CPU(cpu));
> >  
> > -    acc->parent_realize(dev, errp);
> > +    dc_parent->realize(dev, errp);
> >  }
> >  
> >  /* CPU models */
> > @@ -803,14 +805,11 @@ static const ARMCPUInfo arm_cpus[] = {
> >  
> >  static void arm_cpu_class_init(ObjectClass *oc, void *data)
> >  {
> > -    ARMCPUClass *acc = ARM_CPU_CLASS(oc);
> > -    CPUClass *cc = CPU_CLASS(acc);
> > +    CPUClass *cc = CPU_CLASS(oc);
> >      DeviceClass *dc = DEVICE_CLASS(oc);
> >  
> > -    acc->parent_realize = dc->realize;
> >      dc->realize = arm_cpu_realizefn;
> >  
> > -    acc->parent_reset = cc->reset;
> >      cc->reset = arm_cpu_reset;
> >  
> >      cc->class_by_name = arm_cpu_class_by_name;
> > @@ -839,7 +838,6 @@ static const TypeInfo arm_cpu_type_info = {
> >      .instance_init = arm_cpu_initfn,
> >      .instance_finalize = arm_cpu_finalizefn,
> >      .abstract = true,
> > -    .class_size = sizeof(ARMCPUClass),
> >      .class_init = arm_cpu_class_init,
> >  };
> >  

Re: [Qemu-devel] [PATCH qom-next v2 3/5] target-arm: Use parent classes for reset + realize

[Andreas Färber]

Am 11.07.2013 12:31, schrieb Michael S. Tsirkin:
> On Thu, Jul 11, 2013 at 11:47:59AM +0200, Igor Mammedov wrote:
>> On Thu, 11 Jul 2013 11:47:16 +1000
>> peter.crosthwaite@xilinx.com wrote:
>>
>>> From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>>>
>>> ARMCPUClass is only needed for parent-class abstract function access.
>>> Just use parent classes for reset and realize access and remove
>>> ARMCPUClass completely.
>>>
>>> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>>> ---
>>>
>>>  target-arm/cpu-qom.h | 20 --------------------
>>>  target-arm/cpu.c     | 16 +++++++---------
>>>  2 files changed, 7 insertions(+), 29 deletions(-)
>>>
>>> diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
>>> index ef6261f..bdad93a 100644
>>> --- a/target-arm/cpu-qom.h
>>> +++ b/target-arm/cpu-qom.h
>>> @@ -24,28 +24,8 @@
>>>  
>>>  #define TYPE_ARM_CPU "arm-cpu"
>>>  
>>> -#define ARM_CPU_CLASS(klass) \
>>> -    OBJECT_CLASS_CHECK(ARMCPUClass, (klass), TYPE_ARM_CPU)
>>>  #define ARM_CPU(obj) \
>>>      OBJECT_CHECK(ARMCPU, (obj), TYPE_ARM_CPU)
>>> -#define ARM_CPU_GET_CLASS(obj) \
>>> -    OBJECT_GET_CLASS(ARMCPUClass, (obj), TYPE_ARM_CPU)
>>> -
>>> -/**
>>> - * ARMCPUClass:
>>> - * @parent_realize: The parent class' realize handler.
>>> - * @parent_reset: The parent class' reset handler.
>>> - *
>>> - * An ARM CPU model.
>>> - */
>>> -typedef struct ARMCPUClass {
>>> -    /*< private >*/
>>> -    CPUClass parent_class;
>>> -    /*< public >*/
>>> -
>>> -    DeviceRealize parent_realize;
>>> -    void (*parent_reset)(CPUState *cpu);
>>> -} ARMCPUClass;
>>>  
>>>  /**
>>>   * ARMCPU:
>>> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
>>> index ed53df8..ad5ec7b 100644
>>> --- a/target-arm/cpu.c
>>> +++ b/target-arm/cpu.c
>>> @@ -60,7 +60,8 @@ static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
>>>  static void arm_cpu_reset(CPUState *s)
>>>  {
>>>      ARMCPU *cpu = ARM_CPU(s);
>>> -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(cpu);
>>> +    CPUClass *cc_parent =
>>> +            CPU_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
>> Maybe object_class_get_parent_of_type() would be less confusing?
>>
>> This usage assumes that parent of TYPE_ARM_CPU is TYPE_CPU and if
>> another TYPE_X added between them, it might break if TYPE_X doesn't
>> re-implement this logic in its reset.
> 
> If what's needed is TYPE_CPU, you can just look up the class by name.

My suggestion was to hide the implementation details behind an
ARM_CPU_GET_PARENT_CLASS(obj) macro.

That would at the same time allow to later switch to an iterative
approach as seen in v1 without a whole lot of refactoring.

Andreas

> 
>> Could reset be modeled like DEVICE.instance_init() instead? Then
>> no explicit access to parent from child would be needed and it
>> still leaves possibility to override resets if parent->child
>> propagation order is not desirable for a particular device.
>>
>>>      CPUARMState *env = &cpu->env;
>>>  
>>>      if (qemu_loglevel_mask(CPU_LOG_RESET)) {
>>> @@ -68,7 +69,7 @@ static void arm_cpu_reset(CPUState *s)
>>>          log_cpu_state(env, 0);
>>>      }
>>>  
>>> -    acc->parent_reset(s);
>>> +    cc_parent->reset(s);
>>>  
>>>      memset(env, 0, offsetof(CPUARMState, breakpoints));
>>>      g_hash_table_foreach(cpu->cp_regs, cp_reg_reset, cpu);
>>> @@ -158,7 +159,8 @@ static void arm_cpu_finalizefn(Object *obj)
>>>  static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
>>>  {
>>>      ARMCPU *cpu = ARM_CPU(dev);
>>> -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
>>> +    DeviceClass *dc_parent =
>>> +            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
>>>      CPUARMState *env = &cpu->env;
>>>  
>>>      /* Some features automatically imply others: */
>>> @@ -209,7 +211,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
>>>  
>>>      cpu_reset(CPU(cpu));
>>>  
>>> -    acc->parent_realize(dev, errp);
>>> +    dc_parent->realize(dev, errp);
>>>  }
>>>  
>>>  /* CPU models */
>>> @@ -803,14 +805,11 @@ static const ARMCPUInfo arm_cpus[] = {
>>>  
>>>  static void arm_cpu_class_init(ObjectClass *oc, void *data)
>>>  {
>>> -    ARMCPUClass *acc = ARM_CPU_CLASS(oc);
>>> -    CPUClass *cc = CPU_CLASS(acc);
>>> +    CPUClass *cc = CPU_CLASS(oc);
>>>      DeviceClass *dc = DEVICE_CLASS(oc);
>>>  
>>> -    acc->parent_realize = dc->realize;
>>>      dc->realize = arm_cpu_realizefn;
>>>  
>>> -    acc->parent_reset = cc->reset;
>>>      cc->reset = arm_cpu_reset;
>>>  
>>>      cc->class_by_name = arm_cpu_class_by_name;
>>> @@ -839,7 +838,6 @@ static const TypeInfo arm_cpu_type_info = {
>>>      .instance_init = arm_cpu_initfn,
>>>      .instance_finalize = arm_cpu_finalizefn,
>>>      .abstract = true,
>>> -    .class_size = sizeof(ARMCPUClass),
>>>      .class_init = arm_cpu_class_init,
>>>  };
>>>  


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] [PATCH qom-next v2 3/5] target-arm: Use parent classes for reset + realize

[Igor Mammedov]

On Thu, 11 Jul 2013 13:31:15 +0300
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Thu, Jul 11, 2013 at 11:47:59AM +0200, Igor Mammedov wrote:
> > On Thu, 11 Jul 2013 11:47:16 +1000
> > peter.crosthwaite@xilinx.com wrote:
> > 
> > > From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> > > 
> > > ARMCPUClass is only needed for parent-class abstract function access.
> > > Just use parent classes for reset and realize access and remove
> > > ARMCPUClass completely.
> > > 
> > > Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> > > ---
> > > 
> > >  target-arm/cpu-qom.h | 20 --------------------
> > >  target-arm/cpu.c     | 16 +++++++---------
> > >  2 files changed, 7 insertions(+), 29 deletions(-)
> > > 
> > > diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
> > > index ef6261f..bdad93a 100644
> > > --- a/target-arm/cpu-qom.h
> > > +++ b/target-arm/cpu-qom.h
> > > @@ -24,28 +24,8 @@
> > >  
> > >  #define TYPE_ARM_CPU "arm-cpu"
> > >  
> > > -#define ARM_CPU_CLASS(klass) \
> > > -    OBJECT_CLASS_CHECK(ARMCPUClass, (klass), TYPE_ARM_CPU)
> > >  #define ARM_CPU(obj) \
> > >      OBJECT_CHECK(ARMCPU, (obj), TYPE_ARM_CPU)
> > > -#define ARM_CPU_GET_CLASS(obj) \
> > > -    OBJECT_GET_CLASS(ARMCPUClass, (obj), TYPE_ARM_CPU)
> > > -
> > > -/**
> > > - * ARMCPUClass:
> > > - * @parent_realize: The parent class' realize handler.
> > > - * @parent_reset: The parent class' reset handler.
> > > - *
> > > - * An ARM CPU model.
> > > - */
> > > -typedef struct ARMCPUClass {
> > > -    /*< private >*/
> > > -    CPUClass parent_class;
> > > -    /*< public >*/
> > > -
> > > -    DeviceRealize parent_realize;
> > > -    void (*parent_reset)(CPUState *cpu);
> > > -} ARMCPUClass;
> > >  
> > >  /**
> > >   * ARMCPU:
> > > diff --git a/target-arm/cpu.c b/target-arm/cpu.c
> > > index ed53df8..ad5ec7b 100644
> > > --- a/target-arm/cpu.c
> > > +++ b/target-arm/cpu.c
> > > @@ -60,7 +60,8 @@ static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
> > >  static void arm_cpu_reset(CPUState *s)
> > >  {
> > >      ARMCPU *cpu = ARM_CPU(s);
> > > -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(cpu);
> > > +    CPUClass *cc_parent =
> > > +            CPU_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
> > Maybe object_class_get_parent_of_type() would be less confusing?
> > 
> > This usage assumes that parent of TYPE_ARM_CPU is TYPE_CPU and if
> > another TYPE_X added between them, it might break if TYPE_X doesn't
> > re-implement this logic in its reset.
> 
> If what's needed is TYPE_CPU, you can just look up the class by name.

As a quick way to reduce amount of current code /save+override+call/ it will
work too, but adding intermediate TYPE bears the same risk, i.e. children
must be amended to call its reset if it has one.

> 
> > Could reset be modeled like DEVICE.instance_init() instead? Then
> > no explicit access to parent from child would be needed and it
> > still leaves possibility to override resets if parent->child
> > propagation order is not desirable for a particular device.
> > 
> > >      CPUARMState *env = &cpu->env;
> > >  
> > >      if (qemu_loglevel_mask(CPU_LOG_RESET)) {
> > > @@ -68,7 +69,7 @@ static void arm_cpu_reset(CPUState *s)
> > >          log_cpu_state(env, 0);
> > >      }
> > >  
> > > -    acc->parent_reset(s);
> > > +    cc_parent->reset(s);
> > >  
> > >      memset(env, 0, offsetof(CPUARMState, breakpoints));
> > >      g_hash_table_foreach(cpu->cp_regs, cp_reg_reset, cpu);
> > > @@ -158,7 +159,8 @@ static void arm_cpu_finalizefn(Object *obj)
> > >  static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
> > >  {
> > >      ARMCPU *cpu = ARM_CPU(dev);
> > > -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
> > > +    DeviceClass *dc_parent =
> > > +            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
> > >      CPUARMState *env = &cpu->env;
> > >  
> > >      /* Some features automatically imply others: */
> > > @@ -209,7 +211,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
> > >  
> > >      cpu_reset(CPU(cpu));
> > >  
> > > -    acc->parent_realize(dev, errp);
> > > +    dc_parent->realize(dev, errp);
> > >  }
> > >  
> > >  /* CPU models */
> > > @@ -803,14 +805,11 @@ static const ARMCPUInfo arm_cpus[] = {
> > >  
> > >  static void arm_cpu_class_init(ObjectClass *oc, void *data)
> > >  {
> > > -    ARMCPUClass *acc = ARM_CPU_CLASS(oc);
> > > -    CPUClass *cc = CPU_CLASS(acc);
> > > +    CPUClass *cc = CPU_CLASS(oc);
> > >      DeviceClass *dc = DEVICE_CLASS(oc);
> > >  
> > > -    acc->parent_realize = dc->realize;
> > >      dc->realize = arm_cpu_realizefn;
> > >  
> > > -    acc->parent_reset = cc->reset;
> > >      cc->reset = arm_cpu_reset;
> > >  
> > >      cc->class_by_name = arm_cpu_class_by_name;
> > > @@ -839,7 +838,6 @@ static const TypeInfo arm_cpu_type_info = {
> > >      .instance_init = arm_cpu_initfn,
> > >      .instance_finalize = arm_cpu_finalizefn,
> > >      .abstract = true,
> > > -    .class_size = sizeof(ARMCPUClass),
> > >      .class_init = arm_cpu_class_init,
> > >  };
> > >  
> 

Re: [Qemu-devel] [PATCH qom-next v2 3/5] target-arm: Use parent classes for reset + realize

[Peter Crosthwaite]

Hi Igor,

On Thu, Jul 11, 2013 at 7:47 PM, Igor Mammedov <imammedo@redhat.com> wrote:
> On Thu, 11 Jul 2013 11:47:16 +1000
> peter.crosthwaite@xilinx.com wrote:
>
>> From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>>
>> ARMCPUClass is only needed for parent-class abstract function access.
>> Just use parent classes for reset and realize access and remove
>> ARMCPUClass completely.
>>
>> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>> ---
>>
>>  target-arm/cpu-qom.h | 20 --------------------
>>  target-arm/cpu.c     | 16 +++++++---------
>>  2 files changed, 7 insertions(+), 29 deletions(-)
>>
>> diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
>> index ef6261f..bdad93a 100644
>> --- a/target-arm/cpu-qom.h
>> +++ b/target-arm/cpu-qom.h
>> @@ -24,28 +24,8 @@
>>
>>  #define TYPE_ARM_CPU "arm-cpu"
>>
>> -#define ARM_CPU_CLASS(klass) \
>> -    OBJECT_CLASS_CHECK(ARMCPUClass, (klass), TYPE_ARM_CPU)
>>  #define ARM_CPU(obj) \
>>      OBJECT_CHECK(ARMCPU, (obj), TYPE_ARM_CPU)
>> -#define ARM_CPU_GET_CLASS(obj) \
>> -    OBJECT_GET_CLASS(ARMCPUClass, (obj), TYPE_ARM_CPU)
>> -
>> -/**
>> - * ARMCPUClass:
>> - * @parent_realize: The parent class' realize handler.
>> - * @parent_reset: The parent class' reset handler.
>> - *
>> - * An ARM CPU model.
>> - */
>> -typedef struct ARMCPUClass {
>> -    /*< private >*/
>> -    CPUClass parent_class;
>> -    /*< public >*/
>> -
>> -    DeviceRealize parent_realize;
>> -    void (*parent_reset)(CPUState *cpu);
>> -} ARMCPUClass;
>>
>>  /**
>>   * ARMCPU:
>> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
>> index ed53df8..ad5ec7b 100644
>> --- a/target-arm/cpu.c
>> +++ b/target-arm/cpu.c
>> @@ -60,7 +60,8 @@ static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
>>  static void arm_cpu_reset(CPUState *s)
>>  {
>>      ARMCPU *cpu = ARM_CPU(s);
>> -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(cpu);
>> +    CPUClass *cc_parent =
>> +            CPU_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
> Maybe object_class_get_parent_of_type() would be less confusing?
>
> This usage assumes that parent of TYPE_ARM_CPU is TYPE_CPU

It assumes that a parent (could be a grandparent on any level) is
TYPE_CPU not necessarily the direct parent.

> and if
> another TYPE_X added between them, it might break if TYPE_X doesn't
> re-implement this logic in its reset.

That's not really an issue. Assuming your example inheritance heirachy:

TYPE_ARM_CPU -> TYPE_X -> TYPE_CPU

If TYPE_X does not override reset, then TYPE_X inherits
TYPE_CPU::reset as its reset. When TYPE_ARM_CPU does
object_class_get_parent_by_name(TYPE_ARM_CPU), TYPE_X will be
returned, but it will call TYPE_CPU::reset through inheritance anyway.
If TYPE_X does implement a reset, then its TYPE_X's job to call parent
reset as well but that is no different to the status quo anyway.

>
> Could reset be modeled like DEVICE.instance_init() instead? Then
> no explicit access to parent from child would be needed and it
> still leaves possibility to override resets if parent->child
> propagation order is not desirable for a particular device.
>

I don't think thats a good idea. Then reset is inconsistent with other
deviceClass::foo APIs. Leave calling of the parent open coded for the
child to determine. Also the parent should not be allowed to force the
child to call its reset. The child should be able override an API
throwing the original away entirely. The child should also be able to
call the parent version when it wants, rather than us having to worry
about the need for multiple "post or pre" versions.

Regards,
Peter

>>      CPUARMState *env = &cpu->env;
>>
>>      if (qemu_loglevel_mask(CPU_LOG_RESET)) {
>> @@ -68,7 +69,7 @@ static void arm_cpu_reset(CPUState *s)
>>          log_cpu_state(env, 0);
>>      }
>>
>> -    acc->parent_reset(s);
>> +    cc_parent->reset(s);
>>
>>      memset(env, 0, offsetof(CPUARMState, breakpoints));
>>      g_hash_table_foreach(cpu->cp_regs, cp_reg_reset, cpu);
>> @@ -158,7 +159,8 @@ static void arm_cpu_finalizefn(Object *obj)
>>  static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
>>  {
>>      ARMCPU *cpu = ARM_CPU(dev);
>> -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(dev);
>> +    DeviceClass *dc_parent =
>> +            DEVICE_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
>>      CPUARMState *env = &cpu->env;
>>
>>      /* Some features automatically imply others: */
>> @@ -209,7 +211,7 @@ static void arm_cpu_realizefn(DeviceState *dev, Error **errp)
>>
>>      cpu_reset(CPU(cpu));
>>
>> -    acc->parent_realize(dev, errp);
>> +    dc_parent->realize(dev, errp);
>>  }
>>
>>  /* CPU models */
>> @@ -803,14 +805,11 @@ static const ARMCPUInfo arm_cpus[] = {
>>
>>  static void arm_cpu_class_init(ObjectClass *oc, void *data)
>>  {
>> -    ARMCPUClass *acc = ARM_CPU_CLASS(oc);
>> -    CPUClass *cc = CPU_CLASS(acc);
>> +    CPUClass *cc = CPU_CLASS(oc);
>>      DeviceClass *dc = DEVICE_CLASS(oc);
>>
>> -    acc->parent_realize = dc->realize;
>>      dc->realize = arm_cpu_realizefn;
>>
>> -    acc->parent_reset = cc->reset;
>>      cc->reset = arm_cpu_reset;
>>
>>      cc->class_by_name = arm_cpu_class_by_name;
>> @@ -839,7 +838,6 @@ static const TypeInfo arm_cpu_type_info = {
>>      .instance_init = arm_cpu_initfn,
>>      .instance_finalize = arm_cpu_finalizefn,
>>      .abstract = true,
>> -    .class_size = sizeof(ARMCPUClass),
>>      .class_init = arm_cpu_class_init,
>>  };
>>
>
>

Re: [Qemu-devel] [PATCH qom-next v2 3/5] target-arm: Use parent classes for reset + realize

[Peter Crosthwaite]

On Thu, Jul 11, 2013 at 8:36 PM, Andreas Färber <afaerber@suse.de> wrote:
> Am 11.07.2013 12:31, schrieb Michael S. Tsirkin:
>> On Thu, Jul 11, 2013 at 11:47:59AM +0200, Igor Mammedov wrote:
>>> On Thu, 11 Jul 2013 11:47:16 +1000
>>> peter.crosthwaite@xilinx.com wrote:
>>>
>>>> From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>>>>
>>>> ARMCPUClass is only needed for parent-class abstract function access.
>>>> Just use parent classes for reset and realize access and remove
>>>> ARMCPUClass completely.
>>>>
>>>> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
>>>> ---
>>>>
>>>>  target-arm/cpu-qom.h | 20 --------------------
>>>>  target-arm/cpu.c     | 16 +++++++---------
>>>>  2 files changed, 7 insertions(+), 29 deletions(-)
>>>>
>>>> diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
>>>> index ef6261f..bdad93a 100644
>>>> --- a/target-arm/cpu-qom.h
>>>> +++ b/target-arm/cpu-qom.h
>>>> @@ -24,28 +24,8 @@
>>>>
>>>>  #define TYPE_ARM_CPU "arm-cpu"
>>>>
>>>> -#define ARM_CPU_CLASS(klass) \
>>>> -    OBJECT_CLASS_CHECK(ARMCPUClass, (klass), TYPE_ARM_CPU)
>>>>  #define ARM_CPU(obj) \
>>>>      OBJECT_CHECK(ARMCPU, (obj), TYPE_ARM_CPU)
>>>> -#define ARM_CPU_GET_CLASS(obj) \
>>>> -    OBJECT_GET_CLASS(ARMCPUClass, (obj), TYPE_ARM_CPU)
>>>> -
>>>> -/**
>>>> - * ARMCPUClass:
>>>> - * @parent_realize: The parent class' realize handler.
>>>> - * @parent_reset: The parent class' reset handler.
>>>> - *
>>>> - * An ARM CPU model.
>>>> - */
>>>> -typedef struct ARMCPUClass {
>>>> -    /*< private >*/
>>>> -    CPUClass parent_class;
>>>> -    /*< public >*/
>>>> -
>>>> -    DeviceRealize parent_realize;
>>>> -    void (*parent_reset)(CPUState *cpu);
>>>> -} ARMCPUClass;
>>>>
>>>>  /**
>>>>   * ARMCPU:
>>>> diff --git a/target-arm/cpu.c b/target-arm/cpu.c
>>>> index ed53df8..ad5ec7b 100644
>>>> --- a/target-arm/cpu.c
>>>> +++ b/target-arm/cpu.c
>>>> @@ -60,7 +60,8 @@ static void cp_reg_reset(gpointer key, gpointer value, gpointer opaque)
>>>>  static void arm_cpu_reset(CPUState *s)
>>>>  {
>>>>      ARMCPU *cpu = ARM_CPU(s);
>>>> -    ARMCPUClass *acc = ARM_CPU_GET_CLASS(cpu);
>>>> +    CPUClass *cc_parent =
>>>> +            CPU_CLASS(object_class_get_parent_by_name(TYPE_ARM_CPU));
>>> Maybe object_class_get_parent_of_type() would be less confusing?
>>>
>>> This usage assumes that parent of TYPE_ARM_CPU is TYPE_CPU and if
>>> another TYPE_X added between them, it might break if TYPE_X doesn't
>>> re-implement this logic in its reset.
>>
>> If what's needed is TYPE_CPU, you can just look up the class by name.
>

That means the function has knowedge of who the direct parent is which
I am trying to avoid. The goal is the Device::realize function knows
it has to call the parent version. As for who that direct parent is,
that ideally remain abstracted away from here. If you directly
reference a parent class by name you also make it hard to change an
objects parent (which is currently only defined in one place.

> My suggestion was to hide the implementation details behind an
> ARM_CPU_GET_PARENT_CLASS(obj) macro.
>

Respinning. as such. I think this is a good idea. Looks more
consistent with neighbouring code as well.

Regards,
Peter