Commit | Line | Data |
---|---|---|
fa0d1dbf | 1 | #include <linux/bug.h> |
d82227cf RV |
2 | #include <linux/kernel.h> |
3 | #include <asm/opcodes.h> | |
4 | ||
5 | static 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 | ||
35 | static 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 | ||
55 | unsigned 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 | } |