path: root/arch/s390/kernel/ipl.c

/*
 *  arch/s390/kernel/ipl.c
 *    ipl/reipl/dump support for Linux on s390.
 *
 *    Copyright (C) IBM Corp. 2005,2006
 *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
 *		 Heiko Carstens <heiko.carstens@de.ibm.com>
 *		 Volker Sameske <sameske@de.ibm.com>
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/ctype.h>
#include <asm/smp.h>
#include <asm/setup.h>
#include <asm/cpcmd.h>
#include <asm/cio.h>
#include <asm/ebcdic.h>
#include <asm/reset.h>

#define IPL_PARM_BLOCK_VERSION 0
#define LOADPARM_LEN 8

extern char s390_readinfo_sccb[];
#define SCCB_VALID (*((__u16*)&s390_readinfo_sccb[6]) == 0x0010)
#define SCCB_LOADPARM (&s390_readinfo_sccb[24])
#define SCCB_FLAG (s390_readinfo_sccb[91])

enum ipl_type {
	IPL_TYPE_NONE	 = 1,
	IPL_TYPE_UNKNOWN = 2,
	IPL_TYPE_CCW	 = 4,
	IPL_TYPE_FCP	 = 8,
};

#define IPL_NONE_STR	 "none"
#define IPL_UNKNOWN_STR  "unknown"
#define IPL_CCW_STR	 "ccw"
#define IPL_FCP_STR	 "fcp"

static char *ipl_type_str(enum ipl_type type)
{
	switch (type) {
	case IPL_TYPE_NONE:
		return IPL_NONE_STR;
	case IPL_TYPE_CCW:
		return IPL_CCW_STR;
	case IPL_TYPE_FCP:
		return IPL_FCP_STR;
	case IPL_TYPE_UNKNOWN:
	default:
		return IPL_UNKNOWN_STR;
	}
}

enum ipl_method {
	IPL_METHOD_NONE,
	IPL_METHOD_CCW_CIO,
	IPL_METHOD_CCW_DIAG,
	IPL_METHOD_CCW_VM,
	IPL_METHOD_FCP_RO_DIAG,
	IPL_METHOD_FCP_RW_DIAG,
	IPL_METHOD_FCP_RO_VM,
};

enum shutdown_action {
	SHUTDOWN_REIPL,
	SHUTDOWN_DUMP,
	SHUTDOWN_STOP,
};

#define SHUTDOWN_REIPL_STR "reipl"
#define SHUTDOWN_DUMP_STR  "dump"
#define SHUTDOWN_STOP_STR  "stop"

static char *shutdown_action_str(enum shutdown_action action)
{
	switch (action) {
	case SHUTDOWN_REIPL:
		return SHUTDOWN_REIPL_STR;
	case SHUTDOWN_DUMP:
		return SHUTDOWN_DUMP_STR;
	case SHUTDOWN_STOP:
		return SHUTDOWN_STOP_STR;
	default:
		BUG();
	}
}

enum diag308_subcode  {
	DIAG308_IPL   = 3,
	DIAG308_DUMP  = 4,
	DIAG308_SET   = 5,
	DIAG308_STORE = 6,
};

enum diag308_ipl_type {
	DIAG308_IPL_TYPE_FCP = 0,
	DIAG308_IPL_TYPE_CCW = 2,
};

enum diag308_opt {
	DIAG308_IPL_OPT_IPL  = 0x10,
	DIAG308_IPL_OPT_DUMP = 0x20,
};

enum diag308_rc {
	DIAG308_RC_OK = 1,
};

static int diag308_set_works = 0;

static int reipl_capabilities = IPL_TYPE_UNKNOWN;
static enum ipl_type reipl_type = IPL_TYPE_UNKNOWN;
static enum ipl_method reipl_method = IPL_METHOD_NONE;
static struct ipl_parameter_block *reipl_block_fcp;
static struct ipl_parameter_block *reipl_block_ccw;

static int dump_capabilities = IPL_TYPE_NONE;
static enum ipl_type dump_type = IPL_TYPE_NONE;
static enum ipl_method dump_method = IPL_METHOD_NONE;
static struct ipl_parameter_block *dump_block_fcp;
static struct ipl_parameter_block *dump_block_ccw;

static enum shutdown_action on_panic_action = SHUTDOWN_STOP;

static int diag308(unsigned long subcode, void *addr)
{
	register unsigned long _addr asm("0") = (unsigned long) addr;
	register unsigned long _rc asm("1") = 0;

	asm volatile(
		"	diag	%0,%2,0x308\n"
		"0:\n"
		EX_TABLE(0b,0b)
		: "+d" (_addr), "+d" (_rc)
		: "d" (subcode) : "cc", "memory");
	return _rc;
}

/* SYSFS */

#define DEFINE_IPL_ATTR_RO(_prefix, _name, _format, _value)		\
static ssize_t sys_##_prefix##_##_name##_show(struct subsystem *subsys,	\
		char *page)						\
{									\
	return sprintf(page, _format, _value);				\
}									\
static struct subsys_attribute sys_##_prefix##_##_name##_attr =		\
	__ATTR(_name, S_IRUGO, sys_##_prefix##_##_name##_show, NULL);

#define DEFINE_IPL_ATTR_RW(_prefix, _name, _fmt_out, _fmt_in, _value)	\
static ssize_t sys_##_prefix##_##_name##_show(struct subsystem *subsys,	\
		char *page)						\
{									\
	return sprintf(page, _fmt_out,					\
			(unsigned long long) _value);			\
}									\
static ssize_t sys_##_prefix##_##_name##_store(struct subsystem *subsys,\
		const char *buf, size_t len)				\
{									\
	unsigned long long value;					\
	if (sscanf(buf, _fmt_in, &value) != 1)				\
		return -EINVAL;						\
	_value = value;							\
	return len;							\
}									\
static struct subsys_attribute sys_##_prefix##_##_name##_attr =		\
	__ATTR(_name,(S_IRUGO | S_IWUSR),				\
			sys_##_prefix##_##_name##_show,			\
			sys_##_prefix##_##_name##_store);

static void make_attrs_ro(struct attribute **attrs)
{
	while (*attrs) {
		(*attrs)->mode = S_IRUGO;
		attrs++;
	}
}

/*
 * ipl section
 */

static enum ipl_type ipl_get_type(void)
{
	struct ipl_parameter_block *ipl = IPL_PARMBLOCK_START;

	if (!(ipl_flags & IPL_DEVNO_VALID))
		return IPL_TYPE_UNKNOWN;
	if (!(ipl_flags & IPL_PARMBLOCK_VALID))
		return IPL_TYPE_CCW;
	if (ipl->hdr.