1/*
 2 * Jump label s390 support
 3 *
 4 * Copyright IBM Corp. 2011
 5 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
 6 */
 7#include <linux/module.h>
 8#include <linux/uaccess.h>
 9#include <linux/stop_machine.h>
10#include <linux/jump_label.h>
11#include <asm/ipl.h>
12
13#ifdef HAVE_JUMP_LABEL
14
15struct insn {
16	u16 opcode;
17	s32 offset;
18} __packed;
19
20struct insn_args {
21	unsigned long *target;
22	struct insn *insn;
23	ssize_t size;
24};
25
26static int __arch_jump_label_transform(void *data)
27{
28	struct insn_args *args = data;
29	int rc;
30
31	rc = probe_kernel_write(args->target, args->insn, args->size);
32	WARN_ON_ONCE(rc < 0);
33	return 0;
34}
35
36void arch_jump_label_transform(struct jump_entry *entry,
37			       enum jump_label_type type)
38{
39	struct insn_args args;
40	struct insn insn;
41
42	if (type == JUMP_LABEL_ENABLE) {
43		/* brcl 15,offset */
44		insn.opcode = 0xc0f4;
45		insn.offset = (entry->target - entry->code) >> 1;
46	} else {
47		/* brcl 0,0 */
48		insn.opcode = 0xc004;
49		insn.offset = 0;
50	}
51
52	args.target = (void *) entry->code;
53	args.insn = &insn;
54	args.size = JUMP_LABEL_NOP_SIZE;
55
56	stop_machine(__arch_jump_label_transform, &args, NULL);
57}
58
59#endif

 1/*
 2 * Jump label s390 support
 3 *
 4 * Copyright IBM Corp. 2011
 5 * Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
 6 */
 7#include <linux/module.h>
 8#include <linux/uaccess.h>
 9#include <linux/stop_machine.h>
10#include <linux/jump_label.h>
11#include <asm/ipl.h>
12
13#ifdef HAVE_JUMP_LABEL
14
15struct insn {
16	u16 opcode;
17	s32 offset;
18} __packed;
19
20struct insn_args {
21	unsigned long *target;
22	struct insn *insn;
23	ssize_t size;
24};
25
26static int __arch_jump_label_transform(void *data)
27{
28	struct insn_args *args = data;
29	int rc;
30
31	rc = probe_kernel_write(args->target, args->insn, args->size);
32	WARN_ON_ONCE(rc < 0);
33	return 0;
34}
35
36void arch_jump_label_transform(struct jump_entry *entry,
37			       enum jump_label_type type)
38{
39	struct insn_args args;
40	struct insn insn;
41
42	if (type == JUMP_LABEL_ENABLE) {
43		/* brcl 15,offset */
44		insn.opcode = 0xc0f4;
45		insn.offset = (entry->target - entry->code) >> 1;
46	} else {
47		/* brcl 0,0 */
48		insn.opcode = 0xc004;
49		insn.offset = 0;
50	}
51
52	args.target = (void *) entry->code;
53	args.insn = &insn;
54	args.size = JUMP_LABEL_NOP_SIZE;
55
56	stop_machine(__arch_jump_label_transform, &args, NULL);
57}
58
59#endif