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