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) __section(data);
  16 static bool have_vt220 __section(data);
  17 static bool have_linemode __section(data);
  18
  19 static void _sclp_wait_int(void)
  20 {
  21         unsigned long cr0, cr0_new, psw_mask, addr;
  22         psw_t psw_ext_save, psw_wait;
  23
  24         __ctl_store(cr0, 0, 0);
  25         cr0_new = cr0 | 0x200;
  26         __ctl_load(cr0_new, 0, 0);
  27
  28         psw_ext_save = S390_lowcore.external_new_psw;
  29         psw_mask = __extract_psw();
  30         S390_lowcore.external_new_psw.mask = psw_mask;
  31         psw_wait.mask = psw_mask | PSW_MASK_EXT | PSW_MASK_WAIT;
  32         S390_lowcore.ext_int_code = 0;
  33
  34         do {
  35                 asm volatile(
  36                         "       larl    %[addr],0f\n"
  37                         "       stg     %[addr],%[psw_wait_addr]\n"
  38                         "       stg     %[addr],%[psw_ext_addr]\n"
  39                         "       lpswe   %[psw_wait]\n"
  40                         "0:\n"
  41                         : [addr] "=&d" (addr),
  42                           [psw_wait_addr] "=Q" (psw_wait.addr),
  43                           [psw_ext_addr] "=Q" (S390_lowcore.external_new_psw.addr)
  44                         : [psw_wait] "Q" (psw_wait)
  45                         : "cc", "memory");
  46         } while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);
  47
  48         __ctl_load(cr0, 0, 0);
  49         S390_lowcore.external_new_psw = psw_ext_save;
  50 }
  51
  52 static int _sclp_servc(unsigned int cmd, char *sccb)
  53 {
  54         unsigned int cc;
  55
  56         do {
  57                 asm volatile(
  58                         "       .insn   rre,0xb2200000,%1,%2\n"
  59                         "       ipm     %0\n"
  60                         : "=d" (cc) : "d" (cmd), "a" (sccb)
  61                         : "cc", "memory");
  62                 cc >>= 28;
  63                 if (cc == 3)
  64                         return -EINVAL;
  65                 _sclp_wait_int();
  66         } while (cc != 0);
  67         return (*(unsigned short *)(sccb + 6) == 0x20) ? 0 : -EIO;
  68 }
  69
  70 static int _sclp_setup(int disable)
  71 {
  72         static unsigned char init_sccb[] = {
  73                 0x00, 0x1c,
  74                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  75                 0x00, 0x04,
  76                 0x80, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x40,
  77                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
  78         };
  79         unsigned int *masks;
  80         int rc;
  81
  82         memcpy(_sclp_work_area, init_sccb, 28);
  83         masks = (unsigned int *)(_sclp_work_area + 12);
  84         if (disable)
  85                 memset(masks, 0, 16);
  86         /* SCLP write mask */
  87         rc = _sclp_servc(0x00780005, _sclp_work_area);
  88         if (rc)
  89                 return rc;
  90         have_vt220 = masks[2] & EVTYP_VT220MSG_MASK;
  91         have_linemode = masks[2] & EVTYP_MSG_MASK;
  92         return 0;
  93 }
  94
  95 /* Output multi-line text using SCLP Message interface. */
  96 static void _sclp_print_lm(const char *str)
  97 {
  98         static unsigned char write_head[] = {
  99                 /* sccb header */
 100                 0x00, 0x52,                                     /* 0 */
 101                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,             /* 2 */
 102                 /* evbuf */
 103                 0x00, 0x4a,                                     /* 8 */
 104                 0x02, 0x00, 0x00, 0x00,                         /* 10 */
 105                 /* mdb */
 106                 0x00, 0x44,                                     /* 14 */
 107                 0x00, 0x01,                                     /* 16 */
 108                 0xd4, 0xc4, 0xc2, 0x40,                         /* 18 */
 109                 0x00, 0x00, 0x00, 0x01,                         /* 22 */
 110                 /* go */
 111                 0x00, 0x38,                                     /* 26 */
 112                 0x00, 0x01,                                     /* 28 */
 113                 0x00, 0x00, 0x00, 0x00,                         /* 30 */
 114                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 34 */
 115                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 42 */
 116                 0x00, 0x00, 0x00, 0x00,                         /* 50 */
 117                 0x00, 0x00,                                     /* 54 */
 118                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 56 */
 119                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 64 */
 120                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 72 */
 121                 0x00, 0x00,                                     /* 80 */
 122         };
 123         static unsigned char write_mto[] = {
 124                 /* mto  */
 125                 0x00, 0x0a,                                     /* 0 */
 126                 0x00, 0x04,                                     /* 2 */
 127                 0x10, 0x00,                                     /* 4 */
 128                 0x00, 0x00, 0x00, 0x00                          /* 6 */
 129         };
 130         unsigned char *ptr, ch;
 131         unsigned int count;
 132
 133         memcpy(_sclp_work_area, write_head, sizeof(write_head));
 134         ptr = _sclp_work_area + sizeof(write_head);
 135         do {
 136                 memcpy(ptr, write_mto, sizeof(write_mto));
 137                 for (count = sizeof(write_mto); (ch = *str++) != 0; count++) {
 138                         if (ch == 0x0a)
 139                                 break;
 140                         ptr[count] = _ascebc[ch];
 141                 }
 142                 /* Update length fields in mto, mdb, evbuf and sccb */
 143                 *(unsigned short *) ptr = count;
 144                 *(unsigned short *)(_sclp_work_area + 14) += count;
 145                 *(unsigned short *)(_sclp_work_area + 8) += count;
 146                 *(unsigned short *)(_sclp_work_area + 0) += count;
 147                 ptr += count;
 148         } while (ch != 0);
 149
 150         /* SCLP write data */
 151         _sclp_servc(0x00760005, _sclp_work_area);
 152 }
 153
 154 /* Output multi-line text (plus a newline) using SCLP VT220
 155  * interface.
 156  */
 157 static void _sclp_print_vt220(const char *str)
 158 {
 159         static unsigned char const write_head[] = {
 160                 /* sccb header */
 161                 0x00, 0x0e,
 162                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 163                 /* evbuf header */
 164                 0x00, 0x06,
 165                 0x1a, 0x00, 0x00, 0x00,
 166         };
 167         size_t len = strlen(str);
 168
 169         if (sizeof(write_head) + len >= sizeof(_sclp_work_area))
 170                 len = sizeof(_sclp_work_area) - sizeof(write_head) - 1;
 171
 172         memcpy(_sclp_work_area, write_head, sizeof(write_head));
 173         memcpy(_sclp_work_area + sizeof(write_head), str, len);
 174         _sclp_work_area[sizeof(write_head) + len] = '\n';
 175
 176         /* Update length fields in evbuf and sccb headers */
 177         *(unsigned short *)(_sclp_work_area + 8) += len + 1;
 178         *(unsigned short *)(_sclp_work_area + 0) += len + 1;
 179
 180         /* SCLP write data */
 181         (void)_sclp_servc(0x00760005, _sclp_work_area);
 182 }
 183
 184 /* Output one or more lines of text on the SCLP console (VT220 and /
 185  * or line-mode). All lines get terminated; no need for a trailing LF.
 186  */
 187 void _sclp_print_early(const char *str)
 188 {
 189         if (_sclp_setup(0) != 0)
 190                 return;
 191         if (have_linemode)
 192                 _sclp_print_lm(str);
 193         if (have_vt220)
 194                 _sclp_print_vt220(str);
 195         _sclp_setup(1);
 196 }