[Qemu-devel] [PATCH v2 2/6] target-arm: add powered off cpu state

[Rob Herring <robherring2@gmail.com>]

From: Rob Herring <rob.herring@linaro.org>

Add tracking of cpu power state in order to support powering off of
cores in system emulation. The initial state is determined by the
start-powered-off QOM property.

Signed-off-by: Rob Herring <rob.herring@linaro.org>
---
v2:
- Add vmstate for powered_off

 target-arm/cpu-qom.h | 2 ++
 target-arm/cpu.c     | 7 ++++++-
 target-arm/machine.c | 5 +++--
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/target-arm/cpu-qom.h b/target-arm/cpu-qom.h
index eaee944..f835900 100644
--- a/target-arm/cpu-qom.h
+++ b/target-arm/cpu-qom.h
@@ -102,6 +102,8 @@ typedef struct ARMCPU {

     /* Should CPU start in PSCI powered-off state? */
     bool start_powered_off;
+    /* CPU currently in PSCI powered-off state */
+    bool powered_off;

     /* [QEMU_]KVM_ARM_TARGET_* constant for this CPU, or
      * QEMU_KVM_ARM_TARGET_NONE if the kernel doesn't support this CPU type.
diff --git a/target-arm/cpu.c b/target-arm/cpu.c
index f46b375..a0f9916 100644
--- a/target-arm/cpu.c
+++ b/target-arm/cpu.c
@@ -40,7 +40,9 @@ static void arm_cpu_set_pc(CPUState *cs, vaddr value)

 static bool arm_cpu_has_work(CPUState *cs)
 {
-    return cs->interrupt_request &
+    ARMCPU *cpu = ARM_CPU(cs);
+
+    return !cpu->powered_off && cs->interrupt_request &
         (CPU_INTERRUPT_FIQ | CPU_INTERRUPT_HARD | CPU_INTERRUPT_EXITTB);
 }

@@ -91,6 +93,9 @@ static void arm_cpu_reset(CPUState *s)
     env->vfp.xregs[ARM_VFP_MVFR1] = cpu->mvfr1;
     env->vfp.xregs[ARM_VFP_MVFR2] = cpu->mvfr2;

+    cpu->powered_off = cpu->start_powered_off;
+    s->halted = cpu->start_powered_off;
+
     if (arm_feature(env, ARM_FEATURE_IWMMXT)) {
         env->iwmmxt.cregs[ARM_IWMMXT_wCID] = 0x69051000 | 'Q';
     }
diff --git a/target-arm/machine.c b/target-arm/machine.c
index 5092dcd..c8aa1d6 100644
--- a/target-arm/machine.c
+++ b/target-arm/machine.c
@@ -218,8 +218,8 @@ static int cpu_post_load(void *opaque, int version_id)

 const VMStateDescription vmstate_arm_cpu = {
     .name = "cpu",
-    .version_id = 17,
-    .minimum_version_id = 17,
+    .version_id = 18,
+    .minimum_version_id = 18,
     .pre_save = cpu_pre_save,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
@@ -259,6 +259,7 @@ const VMStateDescription vmstate_arm_cpu = {
         VMSTATE_UINT64(env.exception.vaddress, ARMCPU),
         VMSTATE_TIMER(gt_timer[GTIMER_PHYS], ARMCPU),
         VMSTATE_TIMER(gt_timer[GTIMER_VIRT], ARMCPU),
+        VMSTATE_BOOL(powered_off, ARMCPU),
         VMSTATE_END_OF_LIST()
     },
     .subsections = (VMStateSubsection[]) {
--
1.9.1