commit 8bac22423e4c3b70082dd6c1b492ccf21f3b5a0c
author Alistair Francis <alistair.francis@xilinx.com> Fri May 29 16:30:05 2015 +1000
committer Edgar E. Iglesias <edgar.iglesias@xilinx.com> Sun Jun 21 17:20:15 2015 +1000
tree a2dba44421686bba491643d92b8cd5e7bb9a75f0
parent 53432dc9ea37d3be4c8efc3023c2382e9da5334a

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

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 @@
 
     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 @@
     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);
 }

target-microblaze/cpu.h

diff --git a/target-microblaze/cpu.h b/target-microblaze/cpu.h
index d73e1c7..534e1cf 100644
--- a/target-microblaze/cpu.h
+++ b/target-microblaze/cpu.h
@@ -260,16 +260,18 @@
 #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"