Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
fa0d1dbf | 2 | #include <linux/bug.h> |
d82227cf RV |
3 | #include <linux/kernel.h> |
4 | #include <asm/opcodes.h> | |
5 | ||
6 | static 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 | ||
36 | static 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 | ||
56 | unsigned 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 | } |