xref: /OK3568_Linux_fs/kernel/arch/microblaze/include/asm/flat.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * uClinux flat-format executables
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Copyright (C) 2005 John Williams <jwilliams@itee.uq.edu.au>
6*4882a593Smuzhiyun  */
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun #ifndef _ASM_MICROBLAZE_FLAT_H
9*4882a593Smuzhiyun #define _ASM_MICROBLAZE_FLAT_H
10*4882a593Smuzhiyun 
11*4882a593Smuzhiyun #include <asm/unaligned.h>
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun /*
14*4882a593Smuzhiyun  * Microblaze works a little differently from other arches, because
15*4882a593Smuzhiyun  * of the MICROBLAZE_64 reloc type. Here, a 32 bit address is split
16*4882a593Smuzhiyun  * over two instructions, an 'imm' instruction which provides the top
17*4882a593Smuzhiyun  * 16 bits, then the instruction "proper" which provides the low 16
18*4882a593Smuzhiyun  * bits.
19*4882a593Smuzhiyun  */
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun /*
22*4882a593Smuzhiyun  * Crack open a symbol reference and extract the address to be
23*4882a593Smuzhiyun  * relocated. rp is a potentially unaligned pointer to the
24*4882a593Smuzhiyun  * reference
25*4882a593Smuzhiyun  */
26*4882a593Smuzhiyun 
flat_get_addr_from_rp(u32 __user * rp,u32 relval,u32 flags,u32 * addr)27*4882a593Smuzhiyun static inline int flat_get_addr_from_rp(u32 __user *rp, u32 relval, u32 flags,
28*4882a593Smuzhiyun 					u32 *addr)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun 	u32 *p = (__force u32 *)rp;
31*4882a593Smuzhiyun 
32*4882a593Smuzhiyun 	/* Is it a split 64/32 reference? */
33*4882a593Smuzhiyun 	if (relval & 0x80000000) {
34*4882a593Smuzhiyun 		/* Grab the two halves of the reference */
35*4882a593Smuzhiyun 		u32 val_hi, val_lo;
36*4882a593Smuzhiyun 
37*4882a593Smuzhiyun 		val_hi = get_unaligned(p);
38*4882a593Smuzhiyun 		val_lo = get_unaligned(p+1);
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun 		/* Crack the address out */
41*4882a593Smuzhiyun 		*addr = ((val_hi & 0xffff) << 16) + (val_lo & 0xffff);
42*4882a593Smuzhiyun 	} else {
43*4882a593Smuzhiyun 		/* Get the address straight out */
44*4882a593Smuzhiyun 		*addr = get_unaligned(p);
45*4882a593Smuzhiyun 	}
46*4882a593Smuzhiyun 
47*4882a593Smuzhiyun 	return 0;
48*4882a593Smuzhiyun }
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun /*
51*4882a593Smuzhiyun  * Insert an address into the symbol reference at rp. rp is potentially
52*4882a593Smuzhiyun  * unaligned.
53*4882a593Smuzhiyun  */
54*4882a593Smuzhiyun 
55*4882a593Smuzhiyun static inline int
flat_put_addr_at_rp(u32 __user * rp,u32 addr,u32 relval)56*4882a593Smuzhiyun flat_put_addr_at_rp(u32 __user *rp, u32 addr, u32 relval)
57*4882a593Smuzhiyun {
58*4882a593Smuzhiyun 	u32 *p = (__force u32 *)rp;
59*4882a593Smuzhiyun 	/* Is this a split 64/32 reloc? */
60*4882a593Smuzhiyun 	if (relval & 0x80000000) {
61*4882a593Smuzhiyun 		/* Get the two "halves" */
62*4882a593Smuzhiyun 		unsigned long val_hi = get_unaligned(p);
63*4882a593Smuzhiyun 		unsigned long val_lo = get_unaligned(p + 1);
64*4882a593Smuzhiyun 
65*4882a593Smuzhiyun 		/* insert the address */
66*4882a593Smuzhiyun 		val_hi = (val_hi & 0xffff0000) | addr >> 16;
67*4882a593Smuzhiyun 		val_lo = (val_lo & 0xffff0000) | (addr & 0xffff);
68*4882a593Smuzhiyun 
69*4882a593Smuzhiyun 		/* store the two halves back into memory */
70*4882a593Smuzhiyun 		put_unaligned(val_hi, p);
71*4882a593Smuzhiyun 		put_unaligned(val_lo, p+1);
72*4882a593Smuzhiyun 	} else {
73*4882a593Smuzhiyun 		/* Put it straight in, no messing around */
74*4882a593Smuzhiyun 		put_unaligned(addr, p);
75*4882a593Smuzhiyun 	}
76*4882a593Smuzhiyun 	return 0;
77*4882a593Smuzhiyun }
78*4882a593Smuzhiyun 
79*4882a593Smuzhiyun #define	flat_get_relocate_addr(rel)	(rel & 0x7fffffff)
80*4882a593Smuzhiyun 
81*4882a593Smuzhiyun #endif /* _ASM_MICROBLAZE_FLAT_H */
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