1/*
2 *  drivers/s390/char/sclp_info.c
3 *
4 *    Copyright IBM Corp. 2007
5 *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
6 */
7
8#include <linux/init.h>
9#include <linux/errno.h>
10#include <linux/string.h>
11#include <asm/sclp.h>
12#include "sclp.h"
13
14struct sclp_readinfo_sccb s390_readinfo_sccb;
15
16void __init sclp_readinfo_early(void)
17{
18	sclp_cmdw_t command;
19	struct sccb_header *sccb;
20	int ret;
21
22	__ctl_set_bit(0, 9); /* enable service signal subclass mask */
23
24	sccb = &s390_readinfo_sccb.header;
25	command = SCLP_CMDW_READ_SCP_INFO_FORCED;
26	while (1) {
27		u16 response;
28
29		memset(&s390_readinfo_sccb, 0, sizeof(s390_readinfo_sccb));
30		sccb->length = sizeof(s390_readinfo_sccb);
31		sccb->control_mask[2] = 0x80;
32
33		ret = sclp_service_call(command, &s390_readinfo_sccb);
34
35		if (ret == -EIO)
36			goto out;
37		if (ret == -EBUSY)
38			continue;
39
40		__load_psw_mask(PSW_BASE_BITS | PSW_MASK_EXT |
41				PSW_MASK_WAIT | PSW_DEFAULT_KEY);
42		local_irq_disable();
43		barrier();
44
45		response = sccb->response_code;
46
47		if (response == 0x10)
48			break;
49
50		if (response != 0x1f0 || command == SCLP_CMDW_READ_SCP_INFO)
51			break;
52
53		command = SCLP_CMDW_READ_SCP_INFO;
54	}
55out:
56	__ctl_clear_bit(0, 9); /* disable service signal subclass mask */
57}
58