1/*
  2 *    Copyright IBM Corp. 2015
  3 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  4 */
  5#include <linux/kernel.h>
  6#include <asm/ebcdic.h>
  7#include <asm/irq.h>
  8#include <asm/lowcore.h>
  9#include <asm/processor.h>
 10#include <asm/sclp.h>
 11
 12#define EVTYP_VT220MSG_MASK	0x00000040
 13#define EVTYP_MSG_MASK		0x40000000
 14
 15static char _sclp_work_area[4096] __aligned(PAGE_SIZE) __section(data);
 16static bool have_vt220 __section(data);
 17static bool have_linemode __section(data);
 18
 19static void _sclp_wait_int(void)
 20{
 21	unsigned long cr0, cr0_new, psw_mask, addr;
 22	psw_t psw_ext_save, psw_wait;
 23
 24	__ctl_store(cr0, 0, 0);
 25	cr0_new = cr0 | 0x200;
 26	__ctl_load(cr0_new, 0, 0);
 27
 28	psw_ext_save = S390_lowcore.external_new_psw;
 29	psw_mask = __extract_psw();
 30	S390_lowcore.external_new_psw.mask = psw_mask;
 31	psw_wait.mask = psw_mask | PSW_MASK_EXT | PSW_MASK_WAIT;
 32	S390_lowcore.ext_int_code = 0;
 33
 34	do {
 35		asm volatile(
 36			"	larl	%[addr],0f\n"
 37			"	stg	%[addr],%[psw_wait_addr]\n"
 38			"	stg	%[addr],%[psw_ext_addr]\n"
 39			"	lpswe	%[psw_wait]\n"
 40			"0:\n"
 41			: [addr] "=&d" (addr),
 42			  [psw_wait_addr] "=Q" (psw_wait.addr),
 43			  [psw_ext_addr] "=Q" (S390_lowcore.external_new_psw.addr)
 44			: [psw_wait] "Q" (psw_wait)
 45			: "cc", "memory");
 46	} while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);
 47
 48	__ctl_load(cr0, 0, 0);
 49	S390_lowcore.external_new_psw = psw_ext_save;
 50}
 51
 52static int _sclp_servc(unsigned int cmd, char *sccb)
 53{
 54	unsigned int cc;
 55
 56	do {
 57		asm volatile(
 58			"	.insn	rre,0xb2200000,%1,%2\n"
 59			"	ipm	%0\n"
 60			: "=d" (cc) : "d" (cmd), "a" (sccb)
 61			: "cc", "memory");
 62		cc >>= 28;
 63		if (cc == 3)
 64			return -EINVAL;
 65		_sclp_wait_int();
 66	} while (cc != 0);
 67	return (*(unsigned short *)(sccb + 6) == 0x20) ? 0 : -EIO;
 68}
 69
 70static int _sclp_setup(int disable)
 71{
 72	static unsigned char init_sccb[] = {
 73		0x00, 0x1c,
 74		0x00, 0x00, 0x00, 0x00,	0x00, 0x00, 0x00, 0x00,
 75		0x00, 0x04,
 76		0x80, 0x00, 0x00, 0x00,	0x40, 0x00, 0x00, 0x40,
 77		0x00, 0x00, 0x00, 0x00,	0x00, 0x00, 0x00, 0x00
 78	};
 79	unsigned int *masks;
 80	int rc;
 81
 82	memcpy(_sclp_work_area, init_sccb, 28);
 83	masks = (unsigned int *)(_sclp_work_area + 12);
 84	if (disable)
 85		memset(masks, 0, 16);
 86	/* SCLP write mask */
 87	rc = _sclp_servc(0x00780005, _sclp_work_area);
 88	if (rc)
 89		return rc;
 90	have_vt220 = masks[2] & EVTYP_VT220MSG_MASK;
 91	have_linemode = masks[2] & EVTYP_MSG_MASK;
 92	return 0;
 93}
 94
 95/* Output multi-line text using SCLP Message interface. */
 96static void _sclp_print_lm(const char *str)
 97{
 98	static unsigned char write_head[] = {
 99		/* sccb header */
100		0x00, 0x52,					/* 0 */
101		0x00, 0x00, 0x00, 0x00, 0x00, 0x00,		/* 2 */
102		/* evbuf */
103		0x00, 0x4a,					/* 8 */
104		0x02, 0x00, 0x00, 0x00,				/* 10 */
105		/* mdb */
106		0x00, 0x44,					/* 14 */
107		0x00, 0x01,					/* 16 */
108		0xd4, 0xc4, 0xc2, 0x40,				/* 18 */
109		0x00, 0x00, 0x00, 0x01,				/* 22 */
110		/* go */
111		0x00, 0x38,					/* 26 */
112		0x00, 0x01,					/* 28 */
113		0x00, 0x00, 0x00, 0x00,				/* 30 */
114		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 34 */
115		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 42 */
116		0x00, 0x00, 0x00, 0x00,				/* 50 */
117		0x00, 0x00,					/* 54 */
118		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 56 */
119		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 64 */
120		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 72 */
121		0x00, 0x00,					/* 80 */
122	};
123	static unsigned char write_mto[] = {
124		/* mto	*/
125		0x00, 0x0a,					/* 0 */
126		0x00, 0x04,					/* 2 */
127		0x10, 0x00,					/* 4 */
128		0x00, 0x00, 0x00, 0x00				/* 6 */
129	};
130	unsigned char *ptr, ch;
131	unsigned int count;
132
133	memcpy(_sclp_work_area, write_head, sizeof(write_head));
134	ptr = _sclp_work_area + sizeof(write_head);
135	do {
136		memcpy(ptr, write_mto, sizeof(write_mto));
137		for (count = sizeof(write_mto); (ch = *str++) != 0; count++) {
138			if (ch == 0x0a)
139				break;
140			ptr[count] = _ascebc[ch];
141		}
142		/* Update length fields in mto, mdb, evbuf and sccb */
143		*(unsigned short *) ptr = count;
144		*(unsigned short *)(_sclp_work_area + 14) += count;
145		*(unsigned short *)(_sclp_work_area + 8) += count;
146		*(unsigned short *)(_sclp_work_area + 0) += count;
147		ptr += count;
148	} while (ch != 0);
149
150	/* SCLP write data */
151	_sclp_servc(0x00760005, _sclp_work_area);
152}
153
154/* Output multi-line text (plus a newline) using SCLP VT220
155 * interface.
156 */
157static void _sclp_print_vt220(const char *str)
158{
159	static unsigned char const write_head[] = {
160		/* sccb header */
161		0x00, 0x0e,
162		0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
163		/* evbuf header */
164		0x00, 0x06,
165		0x1a, 0x00, 0x00, 0x00,
166	};
167	size_t len = strlen(str);
168
169	if (sizeof(write_head) + len >= sizeof(_sclp_work_area))
170		len = sizeof(_sclp_work_area) - sizeof(write_head) - 1;
171
172	memcpy(_sclp_work_area, write_head, sizeof(write_head));
173	memcpy(_sclp_work_area + sizeof(write_head), str, len);
174	_sclp_work_area[sizeof(write_head) + len] = '\n';
175
176	/* Update length fields in evbuf and sccb headers */
177	*(unsigned short *)(_sclp_work_area + 8) += len + 1;
178	*(unsigned short *)(_sclp_work_area + 0) += len + 1;
179
180	/* SCLP write data */
181	(void)_sclp_servc(0x00760005, _sclp_work_area);
182}
183
184/* Output one or more lines of text on the SCLP console (VT220 and /
185 * or line-mode). All lines get terminated; no need for a trailing LF.
186 */
187void _sclp_print_early(const char *str)
188{
189	if (_sclp_setup(0) != 0)
190		return;
191	if (have_linemode)
192		_sclp_print_lm(str);
193	if (have_vt220)
194		_sclp_print_vt220(str);
195	_sclp_setup(1);
196}