S/390 fake TCG implementation

Qemu won't let us run a KVM target without having host TCG support. Well, for
now we don't have any so let's implement a fake target that only stubs out
everything.

I tried to keep the patch as close to Uli's source as possible, so whenever
he feels like it he can easily diff his version against this one.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

dyngen-exec.h

@@ -117,7 +117,7 @@ extern int printf(const char *, ...);
 
 /* The return address may point to the start of the next instruction.
    Subtracting one gets us the call instruction itself.  */
-#if defined(__s390__)
+#if defined(__s390__) && !defined(__s390x__)
 # define GETPC() ((void*)(((unsigned long)__builtin_return_address(0) & 0x7fffffffUL) - 1))
 #elif defined(__arm__)
 /* Thumb return addresses have the low bit set, so we need to subtract two.

tcg/s390/tcg-target.c

@@ -0,0 +1,105 @@
+/*
+ * Tiny Code Generator for QEMU
+ *
+ * Copyright (c) 2009 Ulrich Hecht <uli@suse.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+static const int tcg_target_reg_alloc_order[] = {
+};
+
+static const int tcg_target_call_iarg_regs[] = {
+};
+
+static const int tcg_target_call_oarg_regs[] = {
+};
+
+static void patch_reloc(uint8_t *code_ptr, int type,
+                tcg_target_long value, tcg_target_long addend)
+{
+    tcg_abort();
+}
+
+static inline int tcg_target_get_call_iarg_regs_count(int flags)
+{
+    tcg_abort();
+    return 0;
+}
+
+/* parse target specific constraints */
+static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str)
+{
+    tcg_abort();
+    return 0;
+}
+
+/* Test if a constant matches the constraint. */
+static inline int tcg_target_const_match(tcg_target_long val,
+                const TCGArgConstraint *arg_ct)
+{
+    tcg_abort();
+    return 0;
+}
+
+/* load a register with an immediate value */
+static inline void tcg_out_movi(TCGContext *s, TCGType type,
+                int ret, tcg_target_long arg)
+{
+    tcg_abort();
+}
+
+/* load data without address translation or endianness conversion */
+static inline void tcg_out_ld(TCGContext *s, TCGType type, int arg,
+                int arg1, tcg_target_long arg2)
+{
+    tcg_abort();
+}
+
+static inline void tcg_out_st(TCGContext *s, TCGType type, int arg,
+                              int arg1, tcg_target_long arg2)
+{
+    tcg_abort();
+}
+
+static inline void tcg_out_op(TCGContext *s, int opc,
+                const TCGArg *args, const int *const_args)
+{
+    tcg_abort();
+}
+
+void tcg_target_init(TCGContext *s)
+{
+    /* gets called with KVM */
+}
+
+void tcg_target_qemu_prologue(TCGContext *s)
+{
+    /* gets called with KVM */
+}
+
+static inline void tcg_out_mov(TCGContext *s, int ret, int arg)
+{
+    tcg_abort();
+}
+
+static inline void tcg_out_addi(TCGContext *s, int reg, tcg_target_long val)
+{
+    tcg_abort();
+}

tcg/s390/tcg-target.h

@@ -0,0 +1,69 @@
+/*
+ * Tiny Code Generator for QEMU
+ *
+ * Copyright (c) 2009 Ulrich Hecht <uli@suse.de>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#define TCG_TARGET_S390 1
+
+#define TCG_TARGET_REG_BITS 64
+#define TCG_TARGET_WORDS_BIGENDIAN
+
+enum {
+    TCG_REG_R0 = 0,
+    TCG_REG_R1,
+    TCG_REG_R2,
+    TCG_REG_R3,
+    TCG_REG_R4,
+    TCG_REG_R5,
+    TCG_REG_R6,
+    TCG_REG_R7,
+    TCG_REG_R8,
+    TCG_REG_R9,
+    TCG_REG_R10,
+    TCG_REG_R11,
+    TCG_REG_R12,
+    TCG_REG_R13,
+    TCG_REG_R14,
+    TCG_REG_R15
+};
+#define TCG_TARGET_NB_REGS 16
+
+/* used for function call generation */
+#define TCG_REG_CALL_STACK		TCG_REG_R15
+#define TCG_TARGET_STACK_ALIGN		8
+#define TCG_TARGET_CALL_STACK_OFFSET	0
+
+enum {
+    /* Note: must be synced with dyngen-exec.h */
+    TCG_AREG0 = TCG_REG_R10,
+    TCG_AREG1 = TCG_REG_R7,
+    TCG_AREG2 = TCG_REG_R8,
+    TCG_AREG3 = TCG_REG_R9,
+};
+
+static inline void flush_icache_range(unsigned long start, unsigned long stop)
+{
+#if QEMU_GNUC_PREREQ(4, 1)
+    __builtin___clear_cache((char *) start, (char *) stop);
+#else
+#error not implemented
+#endif
+}