1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/bug.h>
 3#include <linux/kernel.h>
 4#include <asm/opcodes.h>
 5
 6static unsigned long
 7__arm_gen_branch_thumb2(unsigned long pc, unsigned long addr, bool link)
 
 8{
 9	unsigned long s, j1, j2, i1, i2, imm10, imm11;
10	unsigned long first, second;
11	long offset;
12
13	offset = (long)addr - (long)(pc + 4);
14	if (offset < -16777216 || offset > 16777214) {
15		WARN_ON_ONCE(1);
16		return 0;
17	}
18
19	s	= (offset >> 24) & 0x1;
20	i1	= (offset >> 23) & 0x1;
21	i2	= (offset >> 22) & 0x1;
22	imm10	= (offset >> 12) & 0x3ff;
23	imm11	= (offset >>  1) & 0x7ff;
24
25	j1 = (!i1) ^ s;
26	j2 = (!i2) ^ s;
27
28	first = 0xf000 | (s << 10) | imm10;
29	second = 0x9000 | (j1 << 13) | (j2 << 11) | imm11;
30	if (link)
31		second |= 1 << 14;
32
33	return __opcode_thumb32_compose(first, second);
34}
35
36static unsigned long
37__arm_gen_branch_arm(unsigned long pc, unsigned long addr, bool link)
38{
39	unsigned long opcode = 0xea000000;
40	long offset;
41
42	if (link)
43		opcode |= 1 << 24;
44
45	offset = (long)addr - (long)(pc + 8);
46	if (unlikely(offset < -33554432 || offset > 33554428)) {
47		WARN_ON_ONCE(1);
48		return 0;
49	}
50
51	offset = (offset >> 2) & 0x00ffffff;
52
53	return opcode | offset;
54}
55
56unsigned long
57__arm_gen_branch(unsigned long pc, unsigned long addr, bool link)
58{
59	if (IS_ENABLED(CONFIG_THUMB2_KERNEL))
60		return __arm_gen_branch_thumb2(pc, addr, link);
61	else
62		return __arm_gen_branch_arm(pc, addr, link);
63}

 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/bug.h>
 3#include <linux/kernel.h>
 4#include <asm/opcodes.h>
 5
 6static unsigned long __arm_gen_branch_thumb2(unsigned long pc,
 7					     unsigned long addr, bool link,
 8					     bool warn)
 9{
10	unsigned long s, j1, j2, i1, i2, imm10, imm11;
11	unsigned long first, second;
12	long offset;
13
14	offset = (long)addr - (long)(pc + 4);
15	if (offset < -16777216 || offset > 16777214) {
16		WARN_ON_ONCE(warn);
17		return 0;
18	}
19
20	s	= (offset >> 24) & 0x1;
21	i1	= (offset >> 23) & 0x1;
22	i2	= (offset >> 22) & 0x1;
23	imm10	= (offset >> 12) & 0x3ff;
24	imm11	= (offset >>  1) & 0x7ff;
25
26	j1 = (!i1) ^ s;
27	j2 = (!i2) ^ s;
28
29	first = 0xf000 | (s << 10) | imm10;
30	second = 0x9000 | (j1 << 13) | (j2 << 11) | imm11;
31	if (link)
32		second |= 1 << 14;
33
34	return __opcode_thumb32_compose(first, second);
35}
36
37static unsigned long __arm_gen_branch_arm(unsigned long pc, unsigned long addr,
38					  bool link, bool warn)
39{
40	unsigned long opcode = 0xea000000;
41	long offset;
42
43	if (link)
44		opcode |= 1 << 24;
45
46	offset = (long)addr - (long)(pc + 8);
47	if (unlikely(offset < -33554432 || offset > 33554428)) {
48		WARN_ON_ONCE(warn);
49		return 0;
50	}
51
52	offset = (offset >> 2) & 0x00ffffff;
53
54	return opcode | offset;
55}
56
57unsigned long
58__arm_gen_branch(unsigned long pc, unsigned long addr, bool link, bool warn)
59{
60	if (IS_ENABLED(CONFIG_THUMB2_KERNEL))
61		return __arm_gen_branch_thumb2(pc, addr, link, warn);
62	else
63		return __arm_gen_branch_arm(pc, addr, link, warn);
64}