x86/gdbstub: Clean up includes

common/gdbstub.c wants struct gdb_context but only gets it transitively
through asm/debugger.h.  None of */gdbstub.c should include asm/debugger.h so
include xen/gdbstub.h instead.

Forward declare struct cpu_user_regs in xen/gdbstub.h so it doesn't depend on
the include order to compile.

x86/setup.c doesn't need xen/gdbstub.h at all, so drop it.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/gdbstub.c

@@ -18,7 +18,10 @@
  * You should have received a copy of the GNU General Public License
  * along with this program; If not, see <http://www.gnu.org/licenses/>.
  */
-#include <asm/debugger.h>
+#include <asm/uaccess.h>
+#include <asm/x86-defns.h>
+
+#include <xen/gdbstub.h>
 
 u16
 gdb_arch_signal_num(struct cpu_user_regs *regs, unsigned long cookie)

xen/arch/x86/setup.c

@@ -15,7 +15,6 @@
 #include <xen/multiboot.h>
 #include <xen/domain_page.h>
 #include <xen/version.h>
-#include <xen/gdbstub.h>
 #include <xen/hypercall.h>
 #include <xen/keyhandler.h>
 #include <xen/numa.h>

xen/arch/x86/x86_64/gdbstub.c

@@ -17,7 +17,7 @@
  * along with this program; If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <asm/debugger.h>
+#include <xen/gdbstub.h>
 
 #define GDB_REG64(r) gdb_write_to_packet_hex(r, sizeof(u64), ctx)
 #define GDB_REG32(r)  gdb_write_to_packet_hex(r, sizeof(u32), ctx)

xen/common/gdbstub.c

@@ -38,13 +38,14 @@
 #include <xen/serial.h>
 #include <xen/irq.h>
 #include <xen/watchdog.h>
-#include <asm/debugger.h>
 #include <xen/init.h>
 #include <xen/param.h>
 #include <xen/smp.h>
 #include <xen/console.h>
 #include <xen/errno.h>
 #include <xen/delay.h>
+#include <xen/gdbstub.h>
+
 #include <asm/byteorder.h>
 
 /* Printk isn't particularly safe just after we've trapped to the

xen/include/xen/gdbstub.h

@@ -25,6 +25,8 @@
 
 #ifdef CONFIG_CRASH_DEBUG
 
+struct cpu_user_regs;
+
 struct gdb_context {
     int                 serhnd;           /* handle on our serial line */
     int                 console_steal_id; /* handle on stolen console */