S/390 CPU fake emulation

Because Qemu currently requires a TCG target to exist and there are quite some
useful helpers here to lay the groundwork for out KVM target, let's create a
stub TCG emulation target for S390X CPUs.

This is required to make tcg happy. The emulation target itself won't work
though.

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

1 files changed, 122 insertions, 0 deletions

diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
new file mode 100644
index 0000000000..9b10518fe7
--- /dev/null
+++ b/target-s390x/cpu.h
@@ -0,0 +1,122 @@
+/*
+ * S/390 virtual CPU header
+ *
+ *  Copyright (c) 2009 Ulrich Hecht
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
+ */
+#ifndef CPU_S390X_H
+#define CPU_S390X_H
+
+#define TARGET_LONG_BITS 64
+
+#define ELF_MACHINE	EM_S390
+
+#define CPUState struct CPUS390XState
+
+#include "cpu-defs.h"
+
+#include "softfloat.h"
+
+#define NB_MMU_MODES 2 // guess
+#define MMU_USER_IDX 0 // guess
+
+typedef union FPReg {
+    struct {
+#ifdef WORDS_BIGENDIAN
+        float32 e;
+        int32_t __pad;
+#else
+        int32_t __pad;
+        float32 e;
+#endif
+    };
+    float64 d;
+    uint64_t i;
+} FPReg;
+
+typedef struct CPUS390XState {
+    uint64_t regs[16];	/* GP registers */
+
+    uint32_t aregs[16];	/* access registers */
+
+    uint32_t fpc;	/* floating-point control register */
+    FPReg fregs[16]; /* FP registers */
+    float_status fpu_status; /* passed to softfloat lib */
+
+    struct {
+        uint64_t mask;
+        uint64_t addr;
+    } psw;
+
+    int cc; /* condition code (0-3) */
+
+    uint64_t __excp_addr;
+
+    CPU_COMMON
+} CPUS390XState;
+
+#if defined(CONFIG_USER_ONLY)
+static inline void cpu_clone_regs(CPUState *env, target_ulong newsp)
+{
+    if (newsp)
+        env->regs[15] = newsp;
+    env->regs[0] = 0;
+}
+#endif
+
+CPUS390XState *cpu_s390x_init(const char *cpu_model);
+int cpu_s390x_exec(CPUS390XState *s);
+void cpu_s390x_close(CPUS390XState *s);
+
+/* you can call this signal handler from your SIGBUS and SIGSEGV
+   signal handlers to inform the virtual CPU of exceptions. non zero
+   is returned if the signal was handled by the virtual CPU.  */
+int cpu_s390x_signal_handler(int host_signum, void *pinfo,
+                           void *puc);
+int cpu_s390x_handle_mmu_fault (CPUS390XState *env, target_ulong address, int rw,
+                              int mmu_idx, int is_softmuu);
+#define cpu_handle_mmu_fault cpu_s390x_handle_mmu_fault
+
+#define TARGET_PAGE_BITS 12
+
+#define cpu_init cpu_s390x_init
+#define cpu_exec cpu_s390x_exec
+#define cpu_gen_code cpu_s390x_gen_code
+
+#include "cpu-all.h"
+#include "exec-all.h"
+
+#define EXCP_OPEX 1 /* operation exception (sigill) */
+#define EXCP_SVC 2 /* supervisor call (syscall) */
+#define EXCP_ADDR 5 /* addressing exception */
+#define EXCP_EXECUTE_SVC 0xff00000 /* supervisor call via execute insn */
+
+static inline void cpu_pc_from_tb(CPUState *env, TranslationBlock* tb)
+{
+    env->psw.addr = tb->pc;
+}
+
+static inline void cpu_get_tb_cpu_state(CPUState* env, target_ulong *pc,
+                                        target_ulong *cs_base, int *flags)
+{
+    *pc = env->psw.addr;
+    /* XXX this is correct for user-mode emulation, but needs
+     *     the asce register information as well when softmmu
+     *     is implemented in the future */
+    *cs_base = 0;
+    *flags = env->psw.mask;
+}
+#endif