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", type);
  54                 return 0;
  55         }
  56
  57         /*
  58          * Stack-relative relocs contain the offset into the stack, we
  59          * have to add the stack's start address here and return 1 from
  60          * flat_addr_absolute to prevent the normal address calculations
  61          */
  62         if (relval & (1 << 29))
  63                 return val + current->mm->context.end_brk;
  64
  65         if ((flags & FLAT_FLAG_GOTPIC) == 0)
  66                 val = htonl(val);
  67         return val;
  68 }
  69 EXPORT_SYMBOL(bfin_get_addr_from_rp);
  70
  71 /*
  72  * Insert the address ADDR into the symbol reference at RP;
  73  * RELVAL is the raw relocation-table entry from which RP is derived
  74  */
  75 void bfin_put_addr_at_rp(unsigned long *ptr, unsigned long addr,
  76                 unsigned long relval)
  77 {
  78         unsigned short *usptr = (unsigned short *)ptr;
  79         int type = (relval >> 26) & 7;
  80
  81         switch (type) {
  82         case FLAT_BFIN_RELOC_TYPE_16_BIT:
  83                 put_unaligned(addr, usptr);
  84                 pr_debug("new value %x at %p", get_unaligned(usptr), usptr);
  85                 break;
  86
  87         case FLAT_BFIN_RELOC_TYPE_16H_BIT:
  88                 put_unaligned(addr >> 16, usptr);
  89                 pr_debug("new value %x", get_unaligned(usptr));
  90                 break;
  91
  92         case FLAT_BFIN_RELOC_TYPE_32_BIT:
  93                 put_unaligned(addr, ptr);
  94                 pr_debug("new ptr =%lx", get_unaligned(ptr));
  95                 break;
  96         }
  97 }
  98 EXPORT_SYMBOL(bfin_put_addr_at_rp);