xref: /openbmc/linux/arch/sparc/kernel/jump_label.c (revision be709d48)
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 }
48