target/hppa: Drop attempted gdbstub support for hppa64

There is no support for hppa64 in gdb.  Any attempt to provide the
data for the larger hppa64 registers results in an error from gdb.
Mask CR_SAR writes to the width of the register: 5 or 6 bits.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/hppa/gdbstub.c

@@ -21,11 +21,16 @@
 #include "cpu.h"
 #include "gdbstub/helpers.h"
 
+/*
+ * GDB 15 only supports PA1.0 via the remote protocol, and ignores
+ * any provided xml.  Which means that any attempt to provide more
+ * data results in "Remote 'g' packet reply is too long".
+ */
+
 int hppa_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
 {
-    HPPACPU *cpu = HPPA_CPU(cs);
-    CPUHPPAState *env = &cpu->env;
-    target_ureg val;
+    CPUHPPAState *env = cpu_env(cs);
+    uint32_t val;
 
     switch (n) {
     case 0:
@@ -139,24 +144,13 @@ int hppa_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
         break;
     }
 
-    if (TARGET_REGISTER_BITS == 64) {
-        return gdb_get_reg64(mem_buf, val);
-    } else {
-        return gdb_get_reg32(mem_buf, val);
-    }
+    return gdb_get_reg32(mem_buf, val);
 }
 
 int hppa_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
 {
-    HPPACPU *cpu = HPPA_CPU(cs);
-    CPUHPPAState *env = &cpu->env;
-    target_ureg val;
-
-    if (TARGET_REGISTER_BITS == 64) {
-        val = ldq_p(mem_buf);
-    } else {
-        val = ldl_p(mem_buf);
-    }
+    CPUHPPAState *env = cpu_env(cs);
+    uint32_t val = ldl_p(mem_buf);
 
     switch (n) {
     case 0:
@@ -166,7 +160,7 @@ int hppa_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
         env->gr[n] = val;
         break;
     case 32:
-        env->cr[CR_SAR] = val;
+        env->cr[CR_SAR] = val & (hppa_is_pa20(env) ? 63 : 31);
         break;
     case 33:
         env->iaoq_f = val;
@@ -278,5 +272,5 @@ int hppa_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
         }
         break;
     }
-    return sizeof(target_ureg);
+    return 4;
 }