arch/blackfin/kernel/flat.c

   1 /*
   2  *  arch/blackfin/kernel/flat.c
   3  *
   4  *  Copyright (C) 2007 Analog Devices, Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program 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
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/sched.h>
  23 #include <linux/flat.h>
  24
  25 #define FLAT_BFIN_RELOC_TYPE_16_BIT 0
  26 #define FLAT_BFIN_RELOC_TYPE_16H_BIT 1
  27 #define FLAT_BFIN_RELOC_TYPE_32_BIT 2
  28
  29 unsigned long bfin_get_addr_from_rp(unsigned long *ptr,
  30                 unsigned long relval,
  31                 unsigned long flags,
  32                 unsigned long *persistent)
  33 {
  34         unsigned short *usptr = (unsigned short *)ptr;
  35         int type = (relval >> 26) & 7;
  36         unsigned long val;
  37
  38         switch (type) {
  39                 case FLAT_BFIN_RELOC_TYPE_16_BIT:
  40                 case FLAT_BFIN_RELOC_TYPE_16H_BIT:
  41                         usptr = (unsigned short *)ptr;
  42                         pr_debug("*usptr = %x", get_unaligned(usptr));
  43                         val = get_unaligned(usptr);
  44                         val += *persistent;
  45                         break;
  46
  47                 case FLAT_BFIN_RELOC_TYPE_32_BIT:
  48                         pr_debug("*ptr = %lx", get_unaligned(ptr));
  49                         val = get_unaligned(ptr);
  50                         break;
  51
  52                 default:
  53                         pr_debug("BINFMT_FLAT: Unknown relocation type %x\n",
  54                                 type);
  55
  56                         return 0;
  57         }
  58
  59         /*
  60          * Stack-relative relocs contain the offset into the stack, we
  61          * have to add the stack's start address here and return 1 from
  62          * flat_addr_absolute to prevent the normal address calculations
  63          */
  64         if (relval & (1 << 29))
  65                 return val + current->mm->context.end_brk;
  66
  67         if ((flags & FLAT_FLAG_GOTPIC) == 0)
  68                 val = htonl(val);
  69         return val;
  70 }
  71 EXPORT_SYMBOL(bfin_get_addr_from_rp);
  72
  73 /*
  74  * Insert the address ADDR into the symbol reference at RP;
  75  * RELVAL is the raw relocation-table entry from which RP is derived
  76  */
  77 void bfin_put_addr_at_rp(unsigned long *ptr, unsigned long addr,
  78                 unsigned long relval)
  79 {
  80         unsigned short *usptr = (unsigned short *)ptr;
  81         int type = (relval >> 26) & 7;
  82
  83         switch (type) {
  84                 case FLAT_BFIN_RELOC_TYPE_16_BIT:
  85                         put_unaligned(addr, usptr);
  86                         pr_debug("new value %x at %p", get_unaligned(usptr),
  87                                 usptr);
  88                         break;
  89
  90                 case FLAT_BFIN_RELOC_TYPE_16H_BIT:
  91                         put_unaligned(addr >> 16, usptr);
  92                         pr_debug("new value %x", get_unaligned(usptr));
  93                         break;
  94
  95                 case FLAT_BFIN_RELOC_TYPE_32_BIT:
  96                         put_unaligned(addr, ptr);
  97                         pr_debug("new ptr =%lx", get_unaligned(ptr));
  98                         break;
  99         }
 100 }
 101 EXPORT_SYMBOL(bfin_put_addr_at_rp);