[Qemu-devel] [PATCH v2 2/5] target-microblaze: Preserve the pvr registers during reset

[Alistair Francis]

Move the Microblaze PVR registers to the end of the CPUMBState
and preserve them during reset. This is similar to what the
QEMU ARM model does with some of it's registers.

This allows the Microblaze PVR registers to only be set once
at realise instead of constantly at reset.

Signed-off-by: Alistair Francis <address@hidden>
Reviewed-by: Peter Crosthwaite <address@hidden>
---
V2:
 - Remove the memset and cpu_reset functions as they aren't
   required in the realize and I'm touching them anyway.

NOTE: The individual machine resets still write to the PVR
registers on each reset. This is no longer required as it only
needs to be done once. Instead of moving them now, they are
being left there and will be removed when they are all
converted to the standard CPU properties.

 target-microblaze/cpu.c |   40 ++++++++++++++++++++++------------------
 target-microblaze/cpu.h |   10 ++++++----
 2 files changed, 28 insertions(+), 22 deletions(-)

diff --git a/target-microblaze/cpu.c b/target-microblaze/cpu.c
index 67e3182..95be540 100644
--- a/target-microblaze/cpu.c
+++ b/target-microblaze/cpu.c
@@ -63,13 +63,34 @@ static void mb_cpu_reset(CPUState *s)
 
     mcc->parent_reset(s);
 
-    memset(env, 0, sizeof(CPUMBState));
+    memset(env, 0, offsetof(CPUMBState, pvr));
     env->res_addr = RES_ADDR_NONE;
     tlb_flush(s, 1);
 
     /* Disable stack protector.  */
     env->shr = ~0;
 
+#if defined(CONFIG_USER_ONLY)
+    /* start in user mode with interrupts enabled.  */
+    env->sregs[SR_MSR] = MSR_EE | MSR_IE | MSR_VM | MSR_UM;
+#else
+    env->sregs[SR_MSR] = 0;
+    mmu_init(&env->mmu);
+    env->mmu.c_mmu = 3;
+    env->mmu.c_mmu_tlb_access = 3;
+    env->mmu.c_mmu_zones = 16;
+#endif
+}
+
+static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
+{
+    CPUState *cs = CPU(dev);
+    MicroBlazeCPUClass *mcc = MICROBLAZE_CPU_GET_CLASS(dev);
+    MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
+    CPUMBState *env = &cpu->env;
+
+    qemu_init_vcpu(cs);
+
     env->pvr.regs[0] = PVR0_PVR_FULL_MASK \
                        | PVR0_USE_BARREL_MASK \
                        | PVR0_USE_DIV_MASK \
@@ -99,25 +120,8 @@ static void mb_cpu_reset(CPUState *s)
     env->sregs[SR_PC] = cpu->base_vectors;
 
 #if defined(CONFIG_USER_ONLY)
-    /* start in user mode with interrupts enabled.  */
-    env->sregs[SR_MSR] = MSR_EE | MSR_IE | MSR_VM | MSR_UM;
     env->pvr.regs[10] = 0x0c000000; /* Spartan 3a dsp.  */
-#else
-    env->sregs[SR_MSR] = 0;
-    mmu_init(&env->mmu);
-    env->mmu.c_mmu = 3;
-    env->mmu.c_mmu_tlb_access = 3;
-    env->mmu.c_mmu_zones = 16;
 #endif
-}
-
-static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
-{
-    CPUState *cs = CPU(dev);
-    MicroBlazeCPUClass *mcc = MICROBLAZE_CPU_GET_CLASS(dev);
-
-    cpu_reset(cs);
-    qemu_init_vcpu(cs);
 
     mcc->parent_realize(dev, errp);
 }
diff --git a/target-microblaze/cpu.h b/target-microblaze/cpu.h
index 4ea04ac..e4c1cde 100644
--- a/target-microblaze/cpu.h
+++ b/target-microblaze/cpu.h
@@ -260,16 +260,18 @@ struct CPUMBState {
 #define IFLAGS_TB_MASK  (D_FLAG | IMM_FLAG | DRTI_FLAG | DRTE_FLAG | DRTB_FLAG)
     uint32_t iflags;
 
-    struct {
-        uint32_t regs[16];
-    } pvr;
-
 #if !defined(CONFIG_USER_ONLY)
     /* Unified MMU.  */
     struct microblaze_mmu mmu;
 #endif
 
     CPU_COMMON
+
+    /* These fields are preserved on reset.  */
+
+    struct {
+        uint32_t regs[16];
+    } pvr;
 };
 
 #include "cpu-qom.h"
-- 
1.7.1