summaryrefslogtreecommitdiff
path: root/arch/s390/kernel/sclp.c
blob: f08af675f36f5371ce52e219cde59e176fee8c10 (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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/*
 *    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>

#define EVTYP_VT220MSG_MASK	0x00000040
#define EVTYP_MSG_MASK		0x40000000

static char _sclp_work_area[4096] __aligned(PAGE_SIZE) __section(data);
static bool have_vt220 __section(data);
static bool have_linemode __section(data);

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();
	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, 0x40,
		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;
	have_vt220 = masks[2] & EVTYP_VT220MSG_MASK;
	have_linemode = masks[2] & EVTYP_MSG_MASK;
	return 0;
}

/* Output multi-line text using SCLP Message interface. */
static void _sclp_print_lm(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 */
	_sclp_servc(0x00760005, _sclp_work_area);
}

/* Output multi-line text (plus a newline) using SCLP VT220
 * interface.
 */
static void _sclp_print_vt220(const char *str)
{
	static unsigned char const write_head[] = {
		/* sccb header */
		0x00, 0x0e,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		/* evbuf header */
		0x00, 0x06,
		0x1a, 0x00, 0x00, 0x00,
	};
	size_t len = strlen(str);

	if (sizeof(write_head) + len >= sizeof(_sclp_work_area))
		len = sizeof(_sclp_work_area) - sizeof(write_head) - 1;

	memcpy(_sclp_work_area, write_head, sizeof(write_head));
	memcpy(_sclp_work_area + sizeof(write_head), str, len);
	_sclp_work_area[sizeof(write_head) + len] = '\n';

	/* Update length fields in evbuf and sccb headers */
	*(unsigned short *)(_sclp_work_area + 8) += len + 1;
	*(unsigned short *)(_sclp_work_area + 0) += len + 1;

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

/* Output one or more lines of text on the SCLP console (VT220 and /
 * or line-mode). All lines get terminated; no need for a trailing LF.
 */
void _sclp_print_early(const char *str)
{
	if (_sclp_setup(0) != 0)
		return;
	if (have_linemode)
		_sclp_print_lm(str);
	if (have_vt220)
		_sclp_print_vt220(str);
	_sclp_setup(1);
}