target/hppa: Add privilege to MMU index conversion helpers

Add two macros which convert privilege level to/from MMU index:

- PRIV_TO_MMU_IDX(priv)
    returns the MMU index for the given privilege level

- MMU_IDX_TO_PRIV(mmu_idx)
    returns the corresponding privilege level for this MMU index

The introduction of those macros make the code easier to read and
will help to improve performance in follow-up patch.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

target/hppa/cpu.h

@@ -36,6 +36,9 @@
 #define MMU_USER_IDX     3
 #define MMU_PHYS_IDX     4
 
+#define PRIV_TO_MMU_IDX(priv)    (priv)
+#define MMU_IDX_TO_PRIV(mmu_idx) (mmu_idx)
+
 #define TARGET_INSN_START_EXTRA_WORDS 1
 
 /* Hardware exceptions, interrupts, faults, and traps.  */
@@ -236,7 +239,7 @@ static inline int cpu_mmu_index(CPUHPPAState *env, bool ifetch)
     return MMU_USER_IDX;
 #else
     if (env->psw & (ifetch ? PSW_C : PSW_D)) {
-        return env->iaoq_f & 3;
+        return PRIV_TO_MMU_IDX(env->iaoq_f & 3);
     }
     return MMU_PHYS_IDX;  /* mmu disabled */
 #endif

target/hppa/translate.c

@@ -4057,14 +4057,15 @@ static void hppa_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
     ctx->tb_flags = ctx->base.tb->flags;
 
 #ifdef CONFIG_USER_ONLY
-    ctx->privilege = MMU_USER_IDX;
+    ctx->privilege = MMU_IDX_TO_PRIV(MMU_USER_IDX);
     ctx->mmu_idx = MMU_USER_IDX;
-    ctx->iaoq_f = ctx->base.pc_first | MMU_USER_IDX;
-    ctx->iaoq_b = ctx->base.tb->cs_base | MMU_USER_IDX;
+    ctx->iaoq_f = ctx->base.pc_first | ctx->privilege;
+    ctx->iaoq_b = ctx->base.tb->cs_base | ctx->privilege;
     ctx->unalign = (ctx->tb_flags & TB_FLAG_UNALIGN ? MO_UNALN : MO_ALIGN);
 #else
     ctx->privilege = (ctx->tb_flags >> TB_FLAG_PRIV_SHIFT) & 3;
-    ctx->mmu_idx = (ctx->tb_flags & PSW_D ? ctx->privilege : MMU_PHYS_IDX);
+    ctx->mmu_idx = (ctx->tb_flags & PSW_D ?
+                    PRIV_TO_MMU_IDX(ctx->privilege) : MMU_PHYS_IDX);
 
     /* Recover the IAOQ values from the GVA + PRIV.  */
     uint64_t cs_base = ctx->base.tb->cs_base;