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 static char _sclp_work_area[4096] __aligned(PAGE_SIZE);
13
_sclp_wait_int(void)14 static void _sclp_wait_int(void)
15 {
16 unsigned long cr0, cr0_new, psw_mask, addr;
17 psw_t psw_ext_save, psw_wait;
18
19 __ctl_store(cr0, 0, 0);
20 cr0_new = cr0 | 0x200;
21 __ctl_load(cr0_new, 0, 0);
22
23 psw_ext_save = S390_lowcore.external_new_psw;
24 psw_mask = __extract_psw();
25 S390_lowcore.external_new_psw.mask = psw_mask;
26 psw_wait.mask = psw_mask | PSW_MASK_EXT | PSW_MASK_WAIT;
27 S390_lowcore.ext_int_code = 0;
28
29 do {
30 asm volatile(
31 " larl %[addr],0f\n"
32 " stg %[addr],%[psw_wait_addr]\n"
33 " stg %[addr],%[psw_ext_addr]\n"
34 " lpswe %[psw_wait]\n"
35 "0:\n"
36 : [addr] "=&d" (addr),
37 [psw_wait_addr] "=Q" (psw_wait.addr),
38 [psw_ext_addr] "=Q" (S390_lowcore.external_new_psw.addr)
39 : [psw_wait] "Q" (psw_wait)
40 : "cc", "memory");
41 } while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);
42
43 __ctl_load(cr0, 0, 0);
44 S390_lowcore.external_new_psw = psw_ext_save;
45 }
46
_sclp_servc(unsigned int cmd,char * sccb)47 static int _sclp_servc(unsigned int cmd, char *sccb)
48 {
49 unsigned int cc;
50
51 do {
52 asm volatile(
53 " .insn rre,0xb2200000,%1,%2\n"
54 " ipm %0\n"
55 : "=d" (cc) : "d" (cmd), "a" (sccb)
56 : "cc", "memory");
57 cc >>= 28;
58 if (cc == 3)
59 return -EINVAL;
60 _sclp_wait_int();
61 } while (cc != 0);
62 return (*(unsigned short *)(sccb + 6) == 0x20) ? 0 : -EIO;
63 }
64
_sclp_setup(int disable)65 static int _sclp_setup(int disable)
66 {
67 static unsigned char init_sccb[] = {
68 0x00, 0x1c,
69 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
70 0x00, 0x04,
71 0x80, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00,
72 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
73 };
74 unsigned int *masks;
75 int rc;
76
77 memcpy(_sclp_work_area, init_sccb, 28);
78 masks = (unsigned int *)(_sclp_work_area + 12);
79 if (disable)
80 memset(masks, 0, 16);
81 /* SCLP write mask */
82 rc = _sclp_servc(0x00780005, _sclp_work_area);
83 if (rc)
84 return rc;
85 if ((masks[0] & masks[3]) != masks[0] ||
86 (masks[1] & masks[2]) != masks[1])
87 return -EIO;
88 return 0;
89 }
90
_sclp_print(const char * str)91 static int _sclp_print(const char *str)
92 {
93 static unsigned char write_head[] = {
94 /* sccb header */
95 0x00, 0x52, /* 0 */
96 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 2 */
97 /* evbuf */
98 0x00, 0x4a, /* 8 */
99 0x02, 0x00, 0x00, 0x00, /* 10 */
100 /* mdb */
101 0x00, 0x44, /* 14 */
102 0x00, 0x01, /* 16 */
103 0xd4, 0xc4, 0xc2, 0x40, /* 18 */
104 0x00, 0x00, 0x00, 0x01, /* 22 */
105 /* go */
106 0x00, 0x38, /* 26 */
107 0x00, 0x01, /* 28 */
108 0x00, 0x00, 0x00, 0x00, /* 30 */
109 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 34 */
110 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 42 */
111 0x00, 0x00, 0x00, 0x00, /* 50 */
112 0x00, 0x00, /* 54 */
113 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 56 */
114 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 64 */
115 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 72 */
116 0x00, 0x00, /* 80 */
117 };
118 static unsigned char write_mto[] = {
119 /* mto */
120 0x00, 0x0a, /* 0 */
121 0x00, 0x04, /* 2 */
122 0x10, 0x00, /* 4 */
123 0x00, 0x00, 0x00, 0x00 /* 6 */
124 };
125 unsigned char *ptr, ch;
126 unsigned int count;
127
128 memcpy(_sclp_work_area, write_head, sizeof(write_head));
129 ptr = _sclp_work_area + sizeof(write_head);
130 do {
131 memcpy(ptr, write_mto, sizeof(write_mto));
132 for (count = sizeof(write_mto); (ch = *str++) != 0; count++) {
133 if (ch == 0x0a)
134 break;
135 ptr[count] = _ascebc[ch];
136 }
137 /* Update length fields in mto, mdb, evbuf and sccb */
138 *(unsigned short *) ptr = count;
139 *(unsigned short *)(_sclp_work_area + 14) += count;
140 *(unsigned short *)(_sclp_work_area + 8) += count;
141 *(unsigned short *)(_sclp_work_area + 0) += count;
142 ptr += count;
143 } while (ch != 0);
144
145 /* SCLP write data */
146 return _sclp_servc(0x00760005, _sclp_work_area);
147 }
148
_sclp_print_early(const char * str)149 int _sclp_print_early(const char *str)
150 {
151 int rc;
152
153 rc = _sclp_setup(0);
154 if (rc)
155 return rc;
156 rc = _sclp_print(str);
157 if (rc)
158 return rc;
159 return _sclp_setup(1);
160 }
161