Merge branch 'upstream' into upstream-jgarzik
[linux-2.6] / drivers / s390 / char / sclp_info.c
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
14 struct sclp_readinfo_sccb s390_readinfo_sccb;
15
16 void __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         }
55 out:
56         __ctl_clear_bit(0, 9); /* disable service signal subclass mask */
57 }