[Qemu-devel] [PATCH 12/25] target-openrisc: Enable m[tf]spr from user mode

[Richard Henderson <rth@twiddle.net>]

The architecture manual doesn't say these opcodes are user only.
Leaving them disabled excludes user mode from accessing interesting
SPRs like MACLO/MACHI.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 target-openrisc/helper.h     |  4 +--
 target-openrisc/sys_helper.c | 77 +++++++++++++++++---------------------------
 target-openrisc/translate.c  | 32 +++++++-----------
 3 files changed, 43 insertions(+), 70 deletions(-)

diff --git a/target-openrisc/helper.h b/target-openrisc/helper.h
index 4b0a935..ef243cd 100644
--- a/target-openrisc/helper.h
+++ b/target-openrisc/helper.h
@@ -64,5 +64,5 @@ DEF_HELPER_FLAGS_1(fl1, TCG_CALL_NO_RWG_SE, tl, tl)
 DEF_HELPER_FLAGS_1(rfe, 0, void, env)
 
 /* sys */
-DEF_HELPER_FLAGS_4(mtspr, 0, void, env, tl, tl, tl)
-DEF_HELPER_FLAGS_4(mfspr, TCG_CALL_NO_WG, tl, env, tl, tl, tl)
+DEF_HELPER_FLAGS_3(mtspr, 0, void, env, i32, tl)
+DEF_HELPER_FLAGS_2(mfspr, TCG_CALL_NO_WG, tl, env, i32)
diff --git a/target-openrisc/sys_helper.c b/target-openrisc/sys_helper.c
index e0d8893..1530558 100644
--- a/target-openrisc/sys_helper.c
+++ b/target-openrisc/sys_helper.c
@@ -25,12 +25,11 @@
 
 #define TO_SPR(group, number) (((group) << 11) + (number))
 
-void HELPER(mtspr)(CPUOpenRISCState *env,
-                   target_ulong ra, target_ulong rb, target_ulong offset)
+void HELPER(mtspr)(CPUOpenRISCState *env, uint32_t spr, target_ulong rb)
 {
 #ifndef CONFIG_USER_ONLY
-    int spr = (ra | offset);
     int idx;
+#endif
 
     OpenRISCCPU *cpu = openrisc_env_get_cpu(env);
     CPUState *cs = CPU(cpu);
@@ -50,6 +49,7 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
             tlb_flush(cs, 1);
         }
         cpu_set_sr(env, rb);
+#ifndef CONFIG_USER_ONLY
         if (env->sr & SR_DME) {
             env->tlb->cpu_openrisc_map_address_data =
                 &cpu_openrisc_get_phys_data;
@@ -65,6 +65,7 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
             env->tlb->cpu_openrisc_map_address_code =
                 &cpu_openrisc_get_phys_nommu;
         }
+#endif
         break;
 
     case TO_SPR(0, 18): /* PPC */
@@ -82,6 +83,15 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
     case TO_SPR(0, 64): /* ESR */
         env->esr = rb;
         break;
+
+    case TO_SPR(5, 1):  /* MACLO */
+        env->mac = deposit64(env->mac, 0, 32, rb);
+        break;
+    case TO_SPR(5, 2):  /* MACHI */
+        env->mac = deposit64(env->mac, 32, 32, rb);
+        break;
+
+#ifndef CONFIG_USER_ONLY
     case TO_SPR(1, 512) ... TO_SPR(1, 512+DTLB_SIZE-1): /* DTLBW0MR 0-127 */
         idx = spr - TO_SPR(1, 512);
         if (!(rb & 1)) {
@@ -89,7 +99,6 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
         }
         env->tlb->dtlb[0][idx].mr = rb;
         break;
-
     case TO_SPR(1, 640) ... TO_SPR(1, 640+DTLB_SIZE-1): /* DTLBW0TR 0-127 */
         idx = spr - TO_SPR(1, 640);
         env->tlb->dtlb[0][idx].tr = rb;
@@ -108,7 +117,6 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
         }
         env->tlb->itlb[0][idx].mr = rb;
         break;
-
     case TO_SPR(2, 640) ... TO_SPR(2, 640+ITLB_SIZE-1): /* ITLBW0TR 0-127 */
         idx = spr - TO_SPR(2, 640);
         env->tlb->itlb[0][idx].tr = rb;
@@ -120,12 +128,7 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
     case TO_SPR(2, 1280) ... TO_SPR(2, 1407): /* ITLBW3MR 0-127 */
     case TO_SPR(2, 1408) ... TO_SPR(2, 1535): /* ITLBW3TR 0-127 */
         break;
-    case TO_SPR(5, 1):  /* MACLO */
-        env->mac = deposit64(env->mac, 0, 32, rb);
-        break;
-    case TO_SPR(5, 2):  /* MACHI */
-        env->mac = deposit64(env->mac, 32, 32, rb);
-        break;
+
     case TO_SPR(9, 0):  /* PICMR */
         env->picmr |= rb;
         break;
@@ -169,21 +172,19 @@ void HELPER(mtspr)(CPUOpenRISCState *env,
         }
         cpu_openrisc_timer_update(cpu);
         break;
-    default:
+#endif
 
+    default:
         break;
     }
-#endif
 }
 
-target_ulong HELPER(mfspr)(CPUOpenRISCState *env,
-                           target_ulong rd, target_ulong ra, uint32_t offset)
+target_ulong HELPER(mfspr)(CPUOpenRISCState *env, uint32_t spr)
 {
 #ifndef CONFIG_USER_ONLY
-    int spr = (ra | offset);
-    int idx;
-
     OpenRISCCPU *cpu = openrisc_env_get_cpu(env);
+    int idx;
+#endif
 
     switch (spr) {
     case TO_SPR(0, 0): /* VR */
@@ -219,6 +220,14 @@ target_ulong HELPER(mfspr)(CPUOpenRISCState *env,
     case TO_SPR(0, 64): /* ESR */
         return env->esr;
 
+    case TO_SPR(5, 1):  /* MACLO */
+        return (uint32_t)env->mac;
+        break;
+    case TO_SPR(5, 2):  /* MACHI */
+        return env->mac >> 32;
+        break;
+
+#ifndef CONFIG_USER_ONLY
     case TO_SPR(1, 512) ... TO_SPR(1, 512+DTLB_SIZE-1): /* DTLBW0MR 0-127 */
         idx = spr - TO_SPR(1, 512);
         return env->tlb->dtlb[0][idx].mr;
@@ -251,13 +260,6 @@ target_ulong HELPER(mfspr)(CPUOpenRISCState *env,
     case TO_SPR(2, 1408) ... TO_SPR(2, 1535): /* ITLBW3TR 0-127 */
         break;
 
-    case TO_SPR(5, 1):  /* MACLO */
-        return (uint32_t)env->mac;
-        break;
-    case TO_SPR(5, 2):  /* MACHI */
-        return env->mac >> 32;
-        break;
-
     case TO_SPR(9, 0):  /* PICMR */
         return env->picmr;
 
@@ -270,31 +272,10 @@ target_ulong HELPER(mfspr)(CPUOpenRISCState *env,
     case TO_SPR(10, 1): /* TTCR */
         cpu_openrisc_count_update(cpu);
         return env->ttcr;
+#endif
 
     default:
         break;
     }
-#endif
-
-/*If we later need to add tracepoints (or debug printfs) for the return
-value, it may be useful to structure the code like this:
-
-target_ulong ret = 0;
-
-switch() {
-case x:
- ret = y;
- break;
-case z:
- ret = 42;
- break;
-...
-}
-
-later something like trace_spr_read(ret);
-
-return ret;*/
-
-    /* for rd is passed in, if rd unchanged, just keep it back.  */
-    return rd;
+    return 0;
 }
diff --git a/target-openrisc/translate.c b/target-openrisc/translate.c
index 6ca0420..4dde531 100644
--- a/target-openrisc/translate.c
+++ b/target-openrisc/translate.c
@@ -749,32 +749,24 @@ static void dec_misc(DisasContext *dc, uint32_t insn)
 
     case 0x2d:    /* l.mfspr */
         LOG_DIS("l.mfspr r%d, r%d, %d\n", rd, ra, K16);
-#if defined(CONFIG_USER_ONLY)
-        return;
-#else
-        if (dc->mem_idx == MMU_USER_IDX) {
-            gen_illegal_exception(dc);
-            return;
+        {
+            TCGv_i32 tmp = tcg_temp_new_i32();
+            tcg_gen_trunc_tl_i32(tmp, cpu_R[ra]);
+            tcg_gen_ori_i32(tmp, tmp, K16);
+            gen_helper_mfspr(cpu_R[rd], cpu_env, tmp);
+            tcg_temp_free_i32(tmp);
         }
-        t0 = tcg_const_i32(K16);
-        gen_helper_mfspr(cpu_R[rd], cpu_env, cpu_R[rd], cpu_R[ra], t0);
-        tcg_temp_free(t0);
-#endif
         break;
 
     case 0x30:    /* l.mtspr */
         LOG_DIS("l.mtspr r%d, r%d, %d\n", ra, rb, K5_11);
-#if defined(CONFIG_USER_ONLY)
-        return;
-#else
-        if (dc->mem_idx == MMU_USER_IDX) {
-            gen_illegal_exception(dc);
-            return;
+        {
+            TCGv_i32 tmp = tcg_temp_new_i32();
+            tcg_gen_trunc_tl_i32(tmp, cpu_R[ra]);
+            tcg_gen_ori_i32(tmp, tmp, K5_11);
+            gen_helper_mtspr(cpu_env, tmp, cpu_R[rb]);
+            tcg_temp_free_i32(tmp);
         }
-        t0 = tcg_const_tl(K5_11);
-        gen_helper_mtspr(cpu_env, cpu_R[ra], cpu_R[rb], t0);
-        tcg_temp_free(t0);
-#endif
         break;
 
     case 0x34:    /* l.sd */
-- 
2.5.5