user/test/lib/powerpc/44x/map.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License, version 2, as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program; if not, write to the Free Software
  13  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  14  *
  15  * Copyright IBM Corp. 2008
  16  *
  17  * Authors: Hollis Blanchard <hollisb@us.ibm.com>
  18  */
  19
  20 #include "libcflat.h"
  21
  22 #define TLB_SIZE 64
  23
  24 extern void tlbwe(unsigned int index,
  25                   unsigned char tid,
  26                   unsigned int word0,
  27                   unsigned int word1,
  28                   unsigned int word2);
  29
  30 unsigned int next_free_index;
  31
  32 #define PAGE_SHIFT 12
  33 #define PAGE_MASK (~((1<<PAGE_SHIFT)-1))
  34
  35 #define V (1<<9)
  36
  37 void map(unsigned long vaddr, unsigned long paddr)
  38 {
  39         unsigned int w0, w1, w2;
  40
  41         /* We don't install exception handlers, so we can't handle TLB misses,
  42          * so we can't loop around and overwrite entry 0. */
  43         if (next_free_index++ >= TLB_SIZE)
  44                 panic("TLB overflow");
  45
  46         w0 = (vaddr & PAGE_MASK) | V;
  47         w1 = paddr & PAGE_MASK;
  48         w2 = 0x3;
  49
  50         tlbwe(next_free_index, 0, w0, w1, w2);
  51 }