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 #include <linux/config.h>
  16
  17 /*
  18  * In a GENERIC kernel, we have lots of these vectors floating about,
  19  * all but one of which we want to go away.  In a non-GENERIC kernel,
  20  * we want only one, ever.
  21  *
  22  * Accomplish this in the GENERIC kernel by puting all of the vectors
  23  * in the .init.data section where they'll go away.  We'll copy the
  24  * one we want to the real alpha_mv vector in setup_arch.
  25  *
  26  * Accomplish this in a non-GENERIC kernel by ifdef'ing out all but
  27  * one of the vectors, which will not reside in .init.data.  We then
  28  * alias this one vector to alpha_mv, so no copy is needed.
  29  *
  30  * Upshot: set __initdata to nothing for non-GENERIC kernels.
  31  *
  32  * Note we do the same thing for the UNKNOWN kernel, as we need to write
  33  * to the machine vector while setting it up.
  34  */
  35
  36 #if defined(CONFIG_SH_GENERIC) || defined(CONFIG_SH_UNKNOWN)
  37 #define __initmv __attribute__((unused,__section__ (".machvec.init")))
  38 #define ALIAS_MV(x)
  39 #else
  40 #define __initmv
  41
  42 /* GCC actually has a syntax for defining aliases, but is under some
  43    delusion that you shouldn't be able to declare it extern somewhere
  44    else beforehand.  Fine.  We'll do it ourselves.  */
  45 #if 0
  46 #define ALIAS_MV(system) \
  47   struct sh_machine_vector sh_mv __attribute__((alias("mv_"#system)));
  48 #else
  49 #define ALIAS_MV(system) \
  50   asm(".global sh_mv\nsh_mv = mv_"#system );
  51 #endif
  52 #endif /* GENERIC */
  53
  54 #endif /* __SH_MACHVEC_INIT_H */