arch/s390/kernel/sclp.c

   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
  15 static char _sclp_work_area[4096] __aligned(PAGE_SIZE);
  16 static bool have_vt220, have_linemode;
  17
  18 static 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
  51 static 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
  69 static 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. */
  95 static 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  */
 156 static 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  */
 186 void _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 }