1 /*
2 * Copyright 2015 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 *
14 * jump label TILE-Gx support
15 */
16
17 #include <linux/jump_label.h>
18 #include <linux/memory.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/cpu.h>
22
23 #include <asm/cacheflush.h>
24 #include <asm/insn.h>
25
26 #ifdef HAVE_JUMP_LABEL
27
__jump_label_transform(struct jump_entry * e,enum jump_label_type type)28 static void __jump_label_transform(struct jump_entry *e,
29 enum jump_label_type type)
30 {
31 tilegx_bundle_bits opcode;
32 /* Operate on writable kernel text mapping. */
33 unsigned long pc_wr = ktext_writable_addr(e->code);
34
35 if (type == JUMP_LABEL_JMP)
36 opcode = tilegx_gen_branch(e->code, e->target, false);
37 else
38 opcode = NOP();
39
40 *(tilegx_bundle_bits *)pc_wr = opcode;
41 /* Make sure that above mem writes were issued towards the memory. */
42 smp_wmb();
43 }
44
arch_jump_label_transform(struct jump_entry * e,enum jump_label_type type)45 void arch_jump_label_transform(struct jump_entry *e,
46 enum jump_label_type type)
47 {
48 mutex_lock(&text_mutex);
49
50 __jump_label_transform(e, type);
51 flush_icache_range(e->code, e->code + sizeof(tilegx_bundle_bits));
52
53 mutex_unlock(&text_mutex);
54 }
55
arch_jump_label_transform_static(struct jump_entry * e,enum jump_label_type type)56 __init_or_module void arch_jump_label_transform_static(struct jump_entry *e,
57 enum jump_label_type type)
58 {
59 __jump_label_transform(e, type);
60 }
61
62 #endif /* HAVE_JUMP_LABEL */
63