xref: /openbmc/linux/arch/sparc/kernel/jump_label.c (revision 6d99a79c)
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 #ifdef HAVE_JUMP_LABEL
13 
14 void arch_jump_label_transform(struct jump_entry *entry,
15 			       enum jump_label_type type)
16 {
17 	u32 *insn = (u32 *) (unsigned long) entry->code;
18 	u32 val;
19 
20 	if (type == JUMP_LABEL_JMP) {
21 		s32 off = (s32)entry->target - (s32)entry->code;
22 		bool use_v9_branch = false;
23 
24 		BUG_ON(off & 3);
25 
26 #ifdef CONFIG_SPARC64
27 		if (off <= 0xfffff && off >= -0x100000)
28 			use_v9_branch = true;
29 #endif
30 		if (use_v9_branch) {
31 			/* WDISP19 - target is . + immed << 2 */
32 			/* ba,pt %xcc, . + off */
33 			val = 0x10680000 | (((u32) off >> 2) & 0x7ffff);
34 		} else {
35 			/* WDISP22 - target is . + immed << 2 */
36 			BUG_ON(off > 0x7fffff);
37 			BUG_ON(off < -0x800000);
38 			/* ba . + off */
39 			val = 0x10800000 | (((u32) off >> 2) & 0x3fffff);
40 		}
41 	} else {
42 		val = 0x01000000;
43 	}
44 
45 	mutex_lock(&text_mutex);
46 	*insn = val;
47 	flushi(insn);
48 	mutex_unlock(&text_mutex);
49 }
50 
51 #endif
52