PPC: E500: Implement msgclr

This patch implements the msgclr instruction. It is part of the
Embedded.Processor Control specification and clears pending doorbell
interrupts on the current CPU.
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-ppc/helper.h

@@ -358,6 +358,7 @@ DEF_HELPER_FLAGS_1(load_sr, TCG_CALL_CONST, tl, tl);
 DEF_HELPER_FLAGS_2(store_sr, TCG_CALL_CONST, void, tl, tl)
 
 DEF_HELPER_FLAGS_1(602_mfrom, TCG_CALL_CONST | TCG_CALL_PURE, tl, tl)
+DEF_HELPER_1(msgclr, void, tl)
 #endif
 
 DEF_HELPER_3(dlmzb, tl, tl, tl, i32)

target-ppc/op_helper.c

@@ -4514,4 +4514,39 @@ void helper_booke206_tlbflush(uint32_t type)
     booke206_flush_tlb(env, flags, 1);
 }
 
+/* Embedded.Processor Control */
+static int dbell2irq(target_ulong rb)
+{
+    int msg = rb & DBELL_TYPE_MASK;
+    int irq = -1;
+
+    switch (msg) {
+    case DBELL_TYPE_DBELL:
+        irq = PPC_INTERRUPT_DOORBELL;
+        break;
+    case DBELL_TYPE_DBELL_CRIT:
+        irq = PPC_INTERRUPT_CDOORBELL;
+        break;
+    case DBELL_TYPE_G_DBELL:
+    case DBELL_TYPE_G_DBELL_CRIT:
+    case DBELL_TYPE_G_DBELL_MC:
+        /* XXX implement */
+    default:
+        break;
+    }
+
+    return irq;
+}
+
+void helper_msgclr(target_ulong rb)
+{
+    int irq = dbell2irq(rb);
+
+    if (irq < 0) {
+        return;
+    }
+
+    env->pending_interrupts &= ~(1 << irq);
+}
+
 #endif /* !CONFIG_USER_ONLY */

target-ppc/translate.c

@@ -6220,6 +6220,22 @@ static void gen_icbt_440(DisasContext *ctx)
      */
 }
 
+/* Embedded.Processor Control */
+
+static void gen_msgclr(DisasContext *ctx)
+{
+#if defined(CONFIG_USER_ONLY)
+    gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
+#else
+    if (unlikely(ctx->mem_idx == 0)) {
+        gen_inval_exception(ctx, POWERPC_EXCP_PRIV_OPC);
+        return;
+    }
+
+    gen_helper_msgclr(cpu_gpr[rB(ctx->opcode)]);
+#endif
+}
+
 /***                      Altivec vector extension                         ***/
 /* Altivec registers moves */
 
@@ -8610,6 +8626,8 @@ GEN_HANDLER2_E(tlbivax_booke206, "tlbivax", 0x1F, 0x12, 0x18, 0x00000001,
                PPC_NONE, PPC2_BOOKE206),
 GEN_HANDLER2_E(tlbilx_booke206, "tlbilx", 0x1F, 0x12, 0x00, 0x03800001,
                PPC_NONE, PPC2_BOOKE206),
+GEN_HANDLER2_E(msgclr, "msgclr", 0x1F, 0x0E, 0x07, 0x03ff0001,
+               PPC_NONE, PPC2_PRCNTL),
 GEN_HANDLER(wrtee, 0x1F, 0x03, 0x04, 0x000FFC01, PPC_WRTEE),
 GEN_HANDLER(wrteei, 0x1F, 0x03, 0x05, 0x000E7C01, PPC_WRTEE),
 GEN_HANDLER(dlmzb, 0x1F, 0x0E, 0x02, 0x00000000, PPC_440_SPEC),