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-rw-r--r--arch/mips/kernel/jump_label.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c
new file mode 100644
index 000000000000..6001610cfe55
--- /dev/null
+++ b/arch/mips/kernel/jump_label.c
@@ -0,0 +1,54 @@
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2010 Cavium Networks, Inc.
7 */
8
9#include <linux/jump_label.h>
10#include <linux/kernel.h>
11#include <linux/memory.h>
12#include <linux/mutex.h>
13#include <linux/types.h>
14#include <linux/cpu.h>
15
16#include <asm/cacheflush.h>
17#include <asm/inst.h>
18
19#ifdef HAVE_JUMP_LABEL
20
21#define J_RANGE_MASK ((1ul << 28) - 1)
22
23void arch_jump_label_transform(struct jump_entry *e,
24 enum jump_label_type type)
25{
26 union mips_instruction insn;
27 union mips_instruction *insn_p =
28 (union mips_instruction *)(unsigned long)e->code;
29
30 /* Jump only works within a 256MB aligned region. */
31 BUG_ON((e->target & ~J_RANGE_MASK) != (e->code & ~J_RANGE_MASK));
32
33 /* Target must have 4 byte alignment. */
34 BUG_ON((e->target & 3) != 0);
35
36 if (type == JUMP_LABEL_ENABLE) {
37 insn.j_format.opcode = j_op;
38 insn.j_format.target = (e->target & J_RANGE_MASK) >> 2;
39 } else {
40 insn.word = 0; /* nop */
41 }
42
43 get_online_cpus();
44 mutex_lock(&text_mutex);
45 *insn_p = insn;
46
47 flush_icache_range((unsigned long)insn_p,
48 (unsigned long)insn_p + sizeof(*insn_p));
49
50 mutex_unlock(&text_mutex);
51 put_online_cpus();
52}
53
54#endif /* HAVE_JUMP_LABEL */