s390x/gdb: generate target.xml and handle fp/ac as coprocessors

This patch reduces the core registers to the psw and the general purpose
registers. The fpc and ac registers are handled as coprocessors registers by gdb.
This allows to reuse the feature xml files taken from gdb without further
modification and is what other architectures do.

The target.xml is now generated and provided to the gdb client. Therefore, the
client doesn't have to guess which registers are available at which logical
register number.

Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 70 insertions, 21 deletions

diff --git a/target-s390x/gdbstub.c b/target-s390x/gdbstub.c
index 8d55006706..cda80530e4 100644
--- a/target-s390x/gdbstub.c
+++ b/target-s390x/gdbstub.c
@@ -42,14 +42,7 @@ int s390_cpu_gdb_read_register(CPUState *cs, uint8_t *mem_buf, int n)
         return gdb_get_regl(mem_buf, env->psw.addr);
     case S390_R0_REGNUM ... S390_R15_REGNUM:
         return gdb_get_regl(mem_buf, env->regs[n-S390_R0_REGNUM]);
-    case S390_A0_REGNUM ... S390_A15_REGNUM:
-        return gdb_get_reg32(mem_buf, env->aregs[n-S390_A0_REGNUM]);
-    case S390_FPC_REGNUM:
-        return gdb_get_reg32(mem_buf, env->fpc);
-    case S390_F0_REGNUM ... S390_F15_REGNUM:
-        return gdb_get_reg64(mem_buf, env->fregs[n-S390_F0_REGNUM].ll);
     }
-
     return 0;
 }
 
@@ -57,11 +50,7 @@ int s390_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 {
     S390CPU *cpu = S390_CPU(cs);
     CPUS390XState *env = &cpu->env;
-    target_ulong tmpl;
-    uint32_t tmp32;
-    int r = 8;
-    tmpl = ldtul_p(mem_buf);
-    tmp32 = ldl_p(mem_buf);
+    target_ulong tmpl = ldtul_p(mem_buf);
 
     switch (n) {
     case S390_PSWM_REGNUM:
@@ -76,19 +65,79 @@ int s390_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
     case S390_R0_REGNUM ... S390_R15_REGNUM:
         env->regs[n-S390_R0_REGNUM] = tmpl;
         break;
+    default:
+        return 0;
+    }
+    return 8;
+}
+
+/* the values represent the positions in s390-acr.xml */
+#define S390_A0_REGNUM 0
+#define S390_A15_REGNUM 15
+/* total number of registers in s390-acr.xml */
+#define S390_NUM_AC_REGS 16
+
+static int cpu_read_ac_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
+{
+    switch (n) {
     case S390_A0_REGNUM ... S390_A15_REGNUM:
-        env->aregs[n-S390_A0_REGNUM] = tmp32;
-        r = 4;
-        break;
+        return gdb_get_reg32(mem_buf, env->aregs[n]);
+    default:
+        return 0;
+    }
+}
+
+static int cpu_write_ac_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
+{
+    switch (n) {
+    case S390_A0_REGNUM ... S390_A15_REGNUM:
+        env->aregs[n] = ldl_p(mem_buf);
+        return 4;
+    default:
+        return 0;
+    }
+}
+
+/* the values represent the positions in s390-fpr.xml */
+#define S390_FPC_REGNUM 0
+#define S390_F0_REGNUM 1
+#define S390_F15_REGNUM 16
+/* total number of registers in s390-fpr.xml */
+#define S390_NUM_FP_REGS 17
+
+static int cpu_read_fp_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
+{
+    switch (n) {
     case S390_FPC_REGNUM:
-        env->fpc = tmp32;
-        r = 4;
-        break;
+        return gdb_get_reg32(mem_buf, env->fpc);
     case S390_F0_REGNUM ... S390_F15_REGNUM:
-        env->fregs[n-S390_F0_REGNUM].ll = tmpl;
-        break;
+        return gdb_get_reg64(mem_buf, env->fregs[n - S390_F0_REGNUM].ll);
     default:
         return 0;
     }
-    return r;
+}
+
+static int cpu_write_fp_reg(CPUS390XState *env, uint8_t *mem_buf, int n)
+{
+    switch (n) {
+    case S390_FPC_REGNUM:
+        env->fpc = ldl_p(mem_buf);
+        return 4;
+    case S390_F0_REGNUM ... S390_F15_REGNUM:
+        env->fregs[n - S390_F0_REGNUM].ll = ldtul_p(mem_buf);
+        return 8;
+    default:
+        return 0;
+    }
+}
+
+void s390_cpu_gdb_init(CPUState *cs)
+{
+    gdb_register_coprocessor(cs, cpu_read_ac_reg,
+                             cpu_write_ac_reg,
+                             S390_NUM_AC_REGS, "s390-acr.xml", 0);
+
+    gdb_register_coprocessor(cs, cpu_read_fp_reg,
+                             cpu_write_fp_reg,
+                             S390_NUM_FP_REGS, "s390-fpr.xml", 0);
 }