include/asm-sh/machvec_init.h

   1 /*
   2  * include/asm-sh/machvec_init.h
   3  *
   4  * Copyright 2000 Stuart Menefy (stuart.menefy@st.com)
   5  *
   6  * May be copied or modified under the terms of the GNU General Public
   7  * License.  See linux/COPYING for more information.
   8  *
   9  * This file has goodies to help simplify instantiation of machine vectors.
  10  */
  11
  12 #ifndef __SH_MACHVEC_INIT_H
  13 #define __SH_MACHVEC_INIT_H
  14
  15
  16 /*
  17  * In a GENERIC kernel, we have lots of these vectors floating about,
  18  * all but one of which we want to go away.  In a non-GENERIC kernel,
  19  * we want only one, ever.
  20  *
  21  * Accomplish this in the GENERIC kernel by puting all of the vectors
  22  * in the .init.data section where they'll go away.  We'll copy the
  23  * one we want to the real alpha_mv vector in setup_arch.
  24  *
  25  * Accomplish this in a non-GENERIC kernel by ifdef'ing out all but
  26  * one of the vectors, which will not reside in .init.data.  We then
  27  * alias this one vector to alpha_mv, so no copy is needed.
  28  *
  29  * Upshot: set __initdata to nothing for non-GENERIC kernels.
  30  *
  31  * Note we do the same thing for the UNKNOWN kernel, as we need to write
  32  * to the machine vector while setting it up.
  33  */
  34
  35 #if defined(CONFIG_SH_GENERIC) || defined(CONFIG_SH_UNKNOWN)
  36 #define __initmv __attribute__((unused,__section__ (".machvec.init")))
  37 #define ALIAS_MV(x)
  38 #else
  39 #define __initmv
  40
  41 /* GCC actually has a syntax for defining aliases, but is under some
  42    delusion that you shouldn't be able to declare it extern somewhere
  43    else beforehand.  Fine.  We'll do it ourselves.  */
  44 #if 0
  45 #define ALIAS_MV(system) \
  46   struct sh_machine_vector sh_mv __attribute__((alias("mv_"#system)));
  47 #else
  48 #define ALIAS_MV(system) \
  49   asm(".global sh_mv\nsh_mv = mv_"#system );
  50 #endif
  51 #endif /* GENERIC */
  52
  53 #endif /* __SH_MACHVEC_INIT_H */