From 8bac22423e4c3b70082dd6c1b492ccf21f3b5a0c Mon Sep 17 00:00:00 2001
From: Alistair Francis <alistair.francis@xilinx.com>
Date: Fri, 29 May 2015 16:30:05 +1000
Subject: [PATCH] target-microblaze: Preserve the pvr registers during reset

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 <alistair.francis@xilinx.com>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
---
 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 67e3182f70..95be540124 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 d73e1c7286..534e1cf6a5 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"
-- 
2.11.4.GIT