xref: /openbmc/qemu/pc-bios/s390-ccw/sclp.c (revision 764a6ee9)
1 /*
2  * SCLP ASCII access driver
3  *
4  * Copyright (c) 2013 Alexander Graf <agraf@suse.de>
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or (at
7  * your option) any later version. See the COPYING file in the top-level
8  * directory.
9  */
10 
11 #include "libc.h"
12 #include "s390-ccw.h"
13 #include "sclp.h"
14 
15 long write(int fd, const void *str, size_t len);
16 
17 static char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
18 
19 const unsigned char ebc2asc[256] =
20       /* 0123456789abcdef0123456789abcdef */
21         "................................" /* 1F */
22         "................................" /* 3F */
23         " ...........<(+|&.........!$*);." /* 5F first.chr.here.is.real.space */
24         "-/.........,%_>?.........`:#@'=\""/* 7F */
25         ".abcdefghi.......jklmnopqr......" /* 9F */
26         "..stuvwxyz......................" /* BF */
27         ".ABCDEFGHI.......JKLMNOPQR......" /* DF */
28         "..STUVWXYZ......0123456789......";/* FF */
29 
30 /* Perform service call. Return 0 on success, non-zero otherwise. */
31 static int sclp_service_call(unsigned int command, void *sccb)
32 {
33         int cc;
34 
35         asm volatile(
36                 "       .insn   rre,0xb2200000,%1,%2\n"  /* servc %1,%2 */
37                 "       ipm     %0\n"
38                 "       srl     %0,28"
39                 : "=&d" (cc) : "d" (command), "a" (__pa(sccb))
40                 : "cc", "memory");
41         consume_sclp_int();
42         if (cc == 3)
43                 return -EIO;
44         if (cc == 2)
45                 return -EBUSY;
46         return 0;
47 }
48 
49 void sclp_set_write_mask(uint32_t receive_mask, uint32_t send_mask)
50 {
51     WriteEventMask *sccb = (void *)_sccb;
52 
53     sccb->h.length = sizeof(WriteEventMask);
54     sccb->mask_length = sizeof(unsigned int);
55     sccb->cp_receive_mask = receive_mask;
56     sccb->cp_send_mask = send_mask;
57 
58     sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
59 }
60 
61 void sclp_setup(void)
62 {
63     sclp_set_write_mask(0, SCLP_EVENT_MASK_MSG_ASCII);
64 }
65 
66 long write(int fd, const void *str, size_t len)
67 {
68     WriteEventData *sccb = (void *)_sccb;
69     const char *p = str;
70     size_t data_len = 0;
71     size_t i;
72 
73     if (fd != 1 && fd != 2) {
74         return -EIO;
75     }
76 
77     for (i = 0; i < len; i++) {
78         if ((data_len + 1) >= SCCB_DATA_LEN) {
79             /* We would overflow the sccb buffer, abort early */
80             len = i;
81             break;
82         }
83 
84         if (*p == '\n') {
85             /* Terminal emulators might need \r\n, so generate it */
86             sccb->data[data_len++] = '\r';
87         }
88 
89         sccb->data[data_len++] = *p;
90         p++;
91     }
92 
93     sccb->h.length = sizeof(WriteEventData) + data_len;
94     sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
95     sccb->ebh.length = sizeof(EventBufferHeader) + data_len;
96     sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
97     sccb->ebh.flags = 0;
98 
99     sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
100 
101     return len;
102 }
103 
104 void sclp_print(const char *str)
105 {
106     write(1, str, strlen(str));
107 }
108 
109 void sclp_get_loadparm_ascii(char *loadparm)
110 {
111 
112     ReadInfo *sccb = (void *)_sccb;
113 
114     memset((char *)_sccb, 0, sizeof(ReadInfo));
115     sccb->h.length = SCCB_SIZE;
116     if (!sclp_service_call(SCLP_CMDW_READ_SCP_INFO, sccb)) {
117         ebcdic_to_ascii((char *) sccb->loadparm, loadparm, LOADPARM_LEN);
118     }
119 }
120 
121 int sclp_read(char *str, size_t count)
122 {
123     ReadEventData *sccb = (void *)_sccb;
124     char *buf = (char *)(&sccb->ebh) + 7;
125 
126     /* If count exceeds max buffer size, then restrict it to the max size */
127     if (count > SCCB_SIZE - 8) {
128         count = SCCB_SIZE - 8;
129     }
130 
131     sccb->h.length = SCCB_SIZE;
132     sccb->h.function_code = SCLP_UNCONDITIONAL_READ;
133 
134     sclp_service_call(SCLP_CMD_READ_EVENT_DATA, sccb);
135     memcpy(str, buf, count);
136 
137     return sccb->ebh.length - 7;
138 }
139