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

 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}