jump_label: move 'asm goto' support test to Kconfig
[muen/linux.git] / arch / sparc / kernel / jump_label.c
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/types.h>
4 #include <linux/mutex.h>
5 #include <linux/cpu.h>
6
7 #include <linux/jump_label.h>
8 #include <linux/memory.h>
9
10 #include <asm/cacheflush.h>
11
12 void arch_jump_label_transform(struct jump_entry *entry,
13                                enum jump_label_type type)
14 {
15         u32 *insn = (u32 *) (unsigned long) entry->code;
16         u32 val;
17
18         if (type == JUMP_LABEL_JMP) {
19                 s32 off = (s32)entry->target - (s32)entry->code;
20                 bool use_v9_branch = false;
21
22                 BUG_ON(off & 3);
23
24 #ifdef CONFIG_SPARC64
25                 if (off <= 0xfffff && off >= -0x100000)
26                         use_v9_branch = true;
27 #endif
28                 if (use_v9_branch) {
29                         /* WDISP19 - target is . + immed << 2 */
30                         /* ba,pt %xcc, . + off */
31                         val = 0x10680000 | (((u32) off >> 2) & 0x7ffff);
32                 } else {
33                         /* WDISP22 - target is . + immed << 2 */
34                         BUG_ON(off > 0x7fffff);
35                         BUG_ON(off < -0x800000);
36                         /* ba . + off */
37                         val = 0x10800000 | (((u32) off >> 2) & 0x3fffff);
38                 }
39         } else {
40                 val = 0x01000000;
41         }
42
43         mutex_lock(&text_mutex);
44         *insn = val;
45         flushi(insn);
46         mutex_unlock(&text_mutex);
47 }