segment.h

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/*
 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>
 *     economic rights: Technische Universität Dresden (Germany)
 *
 * This file is part of TUD:OS and distributed under the terms of the
 * GNU General Public License 2.
 * Please see the COPYING-GPL-2 file for details.
 *
 * As a special exception, you may use this file as part of a free software
 * library without restriction.  Specifically, if other files instantiate
 * templates or use macros or inline functions from this file, or you compile
 * this file and link it with other files to produce an executable, this
 * file does not by itself cause the resulting executable to be covered by
 * the GNU General Public License.  This exception does not however
 * invalidate any other reasons why the executable file might be covered by
 * the GNU General Public License.
 */
/*****************************************************************************/
#ifndef __L4_SYS__ARCH_X86__SEGMENT_H__
#define __L4_SYS__ARCH_X86__SEGMENT_H__
 
#ifndef L4API_l4f
#error This header file can only be used with a L4API version!
#endif
 
#include <l4/sys/ipc.h>
 
L4_INLINE long
fiasco_ldt_set(l4_cap_idx_t task, void *ldt, unsigned int num_desc,
               unsigned int entry_number_start, l4_utcb_t *utcb);
 
L4_INLINE long
fiasco_gdt_set(l4_cap_idx_t thread, void *desc, unsigned int size,
         unsigned int entry_number_start, l4_utcb_t *utcb);
 
L4_INLINE unsigned
fiasco_gdt_get_entry_offset(l4_cap_idx_t thread, l4_utcb_t *utcb);
 
enum L4_task_ldt_x86_consts
{
  L4_TASK_LDT_X86_ENTRY_SIZE = 8,
  L4_TASK_LDT_X86_MAX_ENTRIES
    = (L4_UTCB_GENERIC_DATA_SIZE - 2)
      / (L4_TASK_LDT_X86_ENTRY_SIZE / (L4_MWORD_BITS / 8)),
};
 
/*****************************************************************************
 *** Implementation
 *****************************************************************************/
 
#include <l4/sys/task.h>
#include <l4/sys/thread.h>
 
L4_INLINE long
fiasco_ldt_set(l4_cap_idx_t task, void *ldt, unsigned int num_desc,
               unsigned int entry_number_start, l4_utcb_t *utcb)
{
  if (num_desc > L4_TASK_LDT_X86_MAX_ENTRIES)
    return -L4_EINVAL;
  l4_utcb_mr_u(utcb)->mr[0] = L4_TASK_LDT_SET_X86_OP;
  l4_utcb_mr_u(utcb)->mr[1] = entry_number_start;
  __builtin_memcpy(&l4_utcb_mr_u(utcb)->mr[2], ldt,
                   num_desc * L4_TASK_LDT_X86_ENTRY_SIZE);
  return l4_error_u(l4_ipc_call(task, utcb, l4_msgtag(L4_PROTO_TASK, 2 + num_desc * 2, 0, 0), L4_IPC_NEVER), utcb);
}
 
L4_INLINE unsigned
fiasco_gdt_get_entry_offset(l4_cap_idx_t thread, l4_utcb_t *utcb)
{
  l4_utcb_mr_u(utcb)->mr[0] = L4_THREAD_X86_GDT_OP;
  if (l4_error_u(l4_ipc_call(thread, utcb, l4_msgtag(L4_PROTO_THREAD, 1, 0, 0), L4_IPC_NEVER), utcb))
    return -1;
  return l4_utcb_mr_u(utcb)->mr[0];
}
 
#endif /* ! __L4_SYS__ARCH_X86__SEGMENT_H__ */