target-arm: Support v6 barriers in linux-user mode

[qemu.git] / target-arm / translate.c

diff --git a/target-arm/translate.c b/target-arm/translate.c
index 34d5e6ef1a7b908af9dee5d14f6bd62e93da09a7..c7961b809711100588bb23cbeea1cae48a138bae 100644 (file)
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -2498,12 +2498,6 @@ static int cp15_user_ok(CPUState *env, uint32_t insn)
         if (op == 2 || (op == 3 && (insn & ARM_CP_RW_BIT)))
             return 1;
     }
-    if (cpn == 7) {
-        /* ISB, DSB, DMB.  */
-        if ((cpm == 5 && op == 4)
-                || (cpm == 10 && (op == 4 || op == 5)))
-            return 1;
-    }
     return 0;
 }
 
@@ -2579,39 +2573,60 @@ static int disas_cp15_insn(CPUState *env, DisasContext *s, uint32_t insn)
         /* cdp */
         return 1;
     }
-    if (IS_USER(s) && !cp15_user_ok(env, insn)) {
-        return 1;
-    }
-
-    /* Pre-v7 versions of the architecture implemented WFI via coprocessor
-     * instructions rather than a separate instruction.
+    /* We special case a number of cp15 instructions which were used
+     * for things which are real instructions in ARMv7. This allows
+     * them to work in linux-user mode which doesn't provide functional
+     * get_cp15/set_cp15 helpers, and is more efficient anyway.
      */
-    if ((insn & 0x0fff0fff) == 0x0e070f90) {
+    switch ((insn & 0x0fff0fff)) {
+    case 0x0e070f90:
         /* 0,c7,c0,4: Standard v6 WFI (also used in some pre-v6 cores).
          * In v7, this must NOP.
          */
+        if (IS_USER(s)) {
+            return 1;
+        }
         if (!arm_feature(env, ARM_FEATURE_V7)) {
             /* Wait for interrupt.  */
             gen_set_pc_im(s->pc);
             s->is_jmp = DISAS_WFI;
         }
         return 0;
-    }
-
-    if ((insn & 0x0fff0fff) == 0x0e070f58) {
+    case 0x0e070f58:
         /* 0,c7,c8,2: Not all pre-v6 cores implemented this WFI,
          * so this is slightly over-broad.
          */
-        if (!arm_feature(env, ARM_FEATURE_V6)) {
+        if (!IS_USER(s) && !arm_feature(env, ARM_FEATURE_V6)) {
             /* Wait for interrupt.  */
             gen_set_pc_im(s->pc);
             s->is_jmp = DISAS_WFI;
             return 0;
         }
-        /* Otherwise fall through to handle via helper function.
+        /* Otherwise continue to handle via helper function.
          * In particular, on v7 and some v6 cores this is one of
          * the VA-PA registers.
          */
+        break;
+    case 0x0e070f3d:
+        /* 0,c7,c13,1: prefetch-by-MVA in v6, NOP in v7 */
+        if (arm_feature(env, ARM_FEATURE_V6)) {
+            return IS_USER(s) ? 1 : 0;
+        }
+        break;
+    case 0x0e070f95: /* 0,c7,c5,4 : ISB */
+    case 0x0e070f9a: /* 0,c7,c10,4: DSB */
+    case 0x0e070fba: /* 0,c7,c10,5: DMB */
+        /* Barriers in both v6 and v7 */
+        if (arm_feature(env, ARM_FEATURE_V6)) {
+            return 0;
+        }
+        break;
+    default:
+        break;
+    }
+
+    if (IS_USER(s) && !cp15_user_ok(env, insn)) {
+        return 1;
     }
 
     rd = (insn >> 12) & 0xf;