linux/drivers/s390/char/sclp_info.c

58 lines
1.2 KiB
C

/*
* drivers/s390/char/sclp_info.c
*
* Copyright IBM Corp. 2007
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <asm/sclp.h>
#include "sclp.h"
struct sclp_readinfo_sccb s390_readinfo_sccb;
void __init sclp_readinfo_early(void)
{
sclp_cmdw_t command;
struct sccb_header *sccb;
int ret;
__ctl_set_bit(0, 9); /* enable service signal subclass mask */
sccb = &s390_readinfo_sccb.header;
command = SCLP_CMDW_READ_SCP_INFO_FORCED;
while (1) {
u16 response;
memset(&s390_readinfo_sccb, 0, sizeof(s390_readinfo_sccb));
sccb->length = sizeof(s390_readinfo_sccb);
sccb->control_mask[2] = 0x80;
ret = sclp_service_call(command, &s390_readinfo_sccb);
if (ret == -EIO)
goto out;
if (ret == -EBUSY)
continue;
__load_psw_mask(PSW_BASE_BITS | PSW_MASK_EXT |
PSW_MASK_WAIT | PSW_DEFAULT_KEY);
local_irq_disable();
barrier();
response = sccb->response_code;
if (response == 0x10)
break;
if (response != 0x1f0 || command == SCLP_CMDW_READ_SCP_INFO)
break;
command = SCLP_CMDW_READ_SCP_INFO;
}
out:
__ctl_clear_bit(0, 9); /* disable service signal subclass mask */
}