summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/sclp.c
blob: fa0bdff1d41305cb61fdc160d381a509ec4a53b7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
/*
 *    Copyright IBM Corp. 2015
 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
 */
#include <linux/kernel.h>
#include <asm/ebcdic.h>
#include <asm/irq.h>
#include <asm/lowcore.h>
#include <asm/processor.h>
#include <asm/sclp.h>

static char _sclp_work_area[4096] __aligned(PAGE_SIZE);

static void _sclp_wait_int(void)
{
	unsigned long cr0, cr0_new, psw_mask, addr;
	psw_t psw_ext_save, psw_wait;

	__ctl_store(cr0, 0, 0);
	cr0_new = cr0 | 0x200;
	__ctl_load(cr0_new, 0, 0);

	psw_ext_save = S390_lowcore.external_new_psw;
	psw_mask = __extract_psw() & (PSW_MASK_EA | PSW_MASK_BA);
	S390_lowcore.external_new_psw.mask = psw_mask;
	psw_wait.mask = psw_mask | PSW_MASK_EXT | PSW_MASK_WAIT;
	S390_lowcore.ext_int_code = 0;

	do {
		asm volatile(
			"	larl	%[addr],0f\n"
			"	stg	%[addr],%[psw_wait_addr]\n"
			"	stg	%[addr],%[psw_ext_addr]\n"
			"	lpswe	%[psw_wait]\n"
			"0:\n"
			: [addr] "=&d" (addr),
			  [psw_wait_addr] "=Q" (psw_wait.addr),
			  [psw_ext_addr] "=Q" (S390_lowcore.external_new_psw.addr)
			: [psw_wait] "Q" (psw_wait)
			: "cc", "memory");
	} while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);

	__ctl_load(cr0, 0, 0);
	S390_lowcore.external_new_psw = psw_ext_save;
}

static int _sclp_servc(unsigned int cmd, char *sccb)
{
	unsigned int cc;

	do {
		asm volatile(
			"	.insn	rre,0xb2200000,%1,%2\n"
			"	ipm	%0\n"
			: "=d" (cc) : "d" (cmd), "a" (sccb)
			: "cc", "memory");
		cc >>= 28;
		if (cc == 3)
			return -EINVAL;
		_sclp_wait_int();
	} while (cc != 0);
	return (*(unsigned short *)(sccb + 6) == 0x20) ? 0 : -EIO;
}

static int _sclp_setup(int disable)
{
	static unsigned char init_sccb[] = {
		0x00, 0x1c,
		0x00, 0x00, 0x00, 0x00,	0x00, 0x00, 0x00, 0x00,
		0x00, 0x04,
		0x80, 0x00, 0x00, 0x00,	0x40, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00,	0x00, 0x00, 0x00, 0x00
	};
	unsigned int *masks;
	int rc;

	memcpy(_sclp_work_area, init_sccb, 28);
	masks = (unsigned int *)(_sclp_work_area + 12);
	if (disable)
		memset(masks, 0, 16);
	/* SCLP write mask */
	rc = _sclp_servc(0x00780005, _sclp_work_area);
	if (rc)
		return rc;
	if ((masks[0] & masks[3]) != masks[0] ||
	    (masks[1] & masks[2]) != masks[1])
		return -EIO;
	return 0;
}

static int _sclp_print(const char *str)
{
	static unsigned char write_head[] = {
		/* sccb header */
		0x00, 0x52,					/* 0 */
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00,		/* 2 */
		/* evbuf */
		0x00, 0x4a,					/* 8 */
		0x02, 0x00, 0x00, 0x00,				/* 10 */
		/* mdb */
		0x00, 0x44,					/* 14 */
		0x00, 0x01,					/* 16 */
		0xd4, 0xc4, 0xc2, 0x40,				/* 18 */
		0x00, 0x00, 0x00, 0x01,				/* 22 */
		/* go */
		0x00, 0x38,					/* 26 */
		0x00, 0x01,					/* 28 */
		0x00, 0x00, 0x00, 0x00,				/* 30 */
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 34 */
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 42 */
		0x00, 0x00, 0x00, 0x00,				/* 50 */
		0x00, 0x00,					/* 54 */
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 56 */
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 64 */
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 72 */
		0x00, 0x00,					/* 80 */
	};
	static unsigned char write_mto[] = {
		/* mto	*/
		0x00, 0x0a,					/* 0 */
		0x00, 0x04,					/* 2 */
		0x10, 0x00,					/* 4 */
		0x00, 0x00, 0x00, 0x00				/* 6 */
	};
	unsigned char *ptr, ch;
	unsigned int count;

	memcpy(_sclp_work_area, write_head, sizeof(write_head));
	ptr = _sclp_work_area + sizeof(write_head);
	do {
		memcpy(ptr, write_mto, sizeof(write_mto));
		for (count = sizeof(write_mto); (ch = *str++) != 0; count++) {
			if (ch == 0x0a)
				break;
			ptr[count] = _ascebc[ch];
		}
		/* Update length fields in mto, mdb, evbuf and sccb */
		*(unsigned short *) ptr = count;
		*(unsigned short *)(_sclp_work_area + 14) += count;
		*(unsigned short *)(_sclp_work_area + 8) += count;
		*(unsigned short *)(_sclp_work_area + 0) += count;
		ptr += count;
	} while (ch != 0);

	/* SCLP write data */
	return _sclp_servc(0x00760005, _sclp_work_area);
}

int _sclp_print_early(const char *str)
{
	int rc;

	rc = _sclp_setup(0);
	if (rc)
		return rc;
	rc = _sclp_print(str);
	if (rc)
		return rc;
	return _sclp_setup(1);
}
OpenPOWER on IntegriCloud