include/exec/page-vary.h

   1 /*
   2  * Definitions for cpus with variable page sizes.
   3  *
   4  *  Copyright (c) 2003 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #ifndef EXEC_PAGE_VARY_H
  21 #define EXEC_PAGE_VARY_H
  22
  23 typedef struct {
  24     bool decided;
  25     int bits;
  26     uint64_t mask;
  27 } TargetPageBits;
  28
  29 #ifdef IN_PAGE_VARY
  30 extern bool set_preferred_target_page_bits_common(int bits);
  31 extern void finalize_target_page_bits_common(int min);
  32 #endif
  33
  34 /**
  35  * set_preferred_target_page_bits:
  36  * @bits: number of bits needed to represent an address within the page
  37  *
  38  * Set the preferred target page size (the actual target page
  39  * size may be smaller than any given CPU's preference).
  40  * Returns true on success, false on failure (which can only happen
  41  * if this is called after the system has already finalized its
  42  * choice of page size and the requested page size is smaller than that).
  43  */
  44 bool set_preferred_target_page_bits(int bits);
  45
  46 /**
  47  * finalize_target_page_bits:
  48  * Commit the final value set by set_preferred_target_page_bits.
  49  */
  50 void finalize_target_page_bits(void);
  51
  52 #endif /* EXEC_PAGE_VARY_H */