[uaccess] Formalise the uaccess API

The userptr_t is now the fundamental type that gets used for conversions.
For example, virt_to_phys() is implemented in terms of virt_to_user() and
user_to_phys().

src/arch/i386/core/gdbidt.S

@@ -2,7 +2,7 @@
  * Interrupt Descriptor Table (IDT) setup and interrupt handlers for GDB stub.
  */
 
-#include <virtaddr.h>
+#include <librm.h>
 
 #define SIZEOF_I386_REGS	32
 #define SIZEOF_I386_FLAGS	4

src/arch/i386/core/gdbmach.c

@@ -19,7 +19,7 @@
 #include <stddef.h>
 #include <stdio.h>
 #include <assert.h>
-#include <virtaddr.h>
+#include <gpxe/uaccess.h>
 #include <gpxe/gdbstub.h>
 #include <gdbmach.h>
 

src/arch/i386/core/pic8259.c

@@ -16,6 +16,7 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <gpxe/io.h>
 #include <pic8259.h>
 
 /** @file

src/arch/i386/core/virtaddr.S

@@ -4,7 +4,7 @@
  *
  */
 
-#include "virtaddr.h"
+#include "librm.h"
 
 	.arch i386
 	.text

src/arch/i386/core/x86_io.c

@@ -65,10 +65,8 @@ static void x86_writeq ( uint64_t data, volatile uint64_t *io_addr ) {
 			       : : "A" ( data ), "r" ( io_addr ) );
 }
 
-PROVIDE_IOAPI_INLINE ( x86, virt_to_phys );
-PROVIDE_IOAPI_INLINE ( x86, phys_to_virt );
-PROVIDE_IOAPI_INLINE ( x86, virt_to_bus );
-PROVIDE_IOAPI_INLINE ( x86, bus_to_virt );
+PROVIDE_IOAPI_INLINE ( x86, phys_to_bus );
+PROVIDE_IOAPI_INLINE ( x86, bus_to_phys );
 PROVIDE_IOAPI_INLINE ( x86, ioremap );
 PROVIDE_IOAPI_INLINE ( x86, iounmap );
 PROVIDE_IOAPI_INLINE ( x86, io_to_bus );

src/arch/i386/drivers/net/undinet.c

@@ -23,6 +23,7 @@
 #include <biosint.h>
 #include <pnpbios.h>
 #include <basemem_packet.h>
+#include <gpxe/io.h>
 #include <gpxe/iobuf.h>
 #include <gpxe/netdevice.h>
 #include <gpxe/if_ether.h>

src/arch/i386/firmware/pcbios/gateA20.c

@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <realmode.h>
 #include <bios.h>
+#include <gpxe/io.h>
 #include <gpxe/timer.h>
 
 #define K_RDWR		0x60		/* keyboard data & cmds (read/write) */