arch/microblaze/include/asm/flat.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * uClinux flat-format executables
   4  *
   5  * Copyright (C) 2005 John Williams <jwilliams@itee.uq.edu.au>
   6  */
   7
   8 #ifndef _ASM_MICROBLAZE_FLAT_H
   9 #define _ASM_MICROBLAZE_FLAT_H
  10
  11 #include <linux/unaligned.h>
  12
  13 /*
  14  * Microblaze works a little differently from other arches, because
  15  * of the MICROBLAZE_64 reloc type. Here, a 32 bit address is split
  16  * over two instructions, an 'imm' instruction which provides the top
  17  * 16 bits, then the instruction "proper" which provides the low 16
  18  * bits.
  19  */
  20
  21 /*
  22  * Crack open a symbol reference and extract the address to be
  23  * relocated. rp is a potentially unaligned pointer to the
  24  * reference
  25  */
  26
  27 static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
  28                                         u32 *addr)
  29 {
  30         u32 *p = (__force u32 *)rp;
  31
  32         /* Is it a split 64/32 reference? */
  33         if (relval & 0x80000000) {
  34                 /* Grab the two halves of the reference */
  35                 u32 val_hi, val_lo;
  36
  37                 val_hi = get_unaligned(p);
  38                 val_lo = get_unaligned(p+1);
  39
  40                 /* Crack the address out */
  41                 *addr = ((val_hi & 0xffff) << 16) + (val_lo & 0xffff);
  42         } else {
  43                 /* Get the address straight out */
  44                 *addr = get_unaligned(p);
  45         }
  46
  47         return 0;
  48 }
  49
  50 /*
  51  * Insert an address into the symbol reference at rp. rp is potentially
  52  * unaligned.
  53  */
  54
  55 static inline int
  56 flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 relval)
  57 {
  58         u32 *p = (__force u32 *)rp;
  59         /* Is this a split 64/32 reloc? */
  60         if (relval & 0x80000000) {
  61                 /* Get the two "halves" */
  62                 unsigned long val_hi = get_unaligned(p);
  63                 unsigned long val_lo = get_unaligned(p + 1);
  64
  65                 /* insert the address */
  66                 val_hi = (val_hi & 0xffff0000) | addr >> 16;
  67                 val_lo = (val_lo & 0xffff0000) | (addr & 0xffff);
  68
  69                 /* store the two halves back into memory */
  70                 put_unaligned(val_hi, p);
  71                 put_unaligned(val_lo, p+1);
  72         } else {
  73                 /* Put it straight in, no messing around */
  74                 put_unaligned(addr, p);
  75         }
  76         return 0;
  77 }
  78
  79 #define flat_get_relocate_addr(rel)     (rel & 0x7fffffff)
  80
  81 #endif /* _ASM_MICROBLAZE_FLAT_H */