pc-bios/s390-ccw/sclp.c

   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 }