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 <asm/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
27static 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
55static inline int
56flat_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 */
82