drivers/s390/char/sclp_early_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    Copyright IBM Corp. 2015
   4  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <asm/processor.h>
   9 #include <asm/lowcore.h>
  10 #include <asm/ctlreg.h>
  11 #include <asm/ebcdic.h>
  12 #include <asm/irq.h>
  13 #include <asm/sections.h>
  14 #include <asm/physmem_info.h>
  15 #include <asm/facility.h>
  16 #include "sclp.h"
  17 #include "sclp_rw.h"
  18
  19 static struct read_info_sccb __bootdata(sclp_info_sccb);
  20 static int __bootdata(sclp_info_sccb_valid);
  21 char *__bootdata_preserved(sclp_early_sccb);
  22 int sclp_init_state = sclp_init_state_uninitialized;
  23 /*
  24  * Used to keep track of the size of the event masks. Qemu until version 2.11
  25  * only supports 4 and needs a workaround.
  26  */
  27 bool sclp_mask_compat_mode;
  28
  29 void sclp_early_wait_irq(void)
  30 {
  31         unsigned long psw_mask, addr;
  32         psw_t psw_ext_save, psw_wait;
  33         union ctlreg0 cr0, cr0_new;
  34
  35         local_ctl_store(0, &cr0.reg);
  36         cr0_new.val = cr0.val & ~CR0_IRQ_SUBCLASS_MASK;
  37         cr0_new.lap = 0;
  38         cr0_new.sssm = 1;
  39         local_ctl_load(0, &cr0_new.reg);
  40
  41         psw_ext_save = S390_lowcore.external_new_psw;
  42         psw_mask = __extract_psw();
  43         S390_lowcore.external_new_psw.mask = psw_mask;
  44         psw_wait.mask = psw_mask | PSW_MASK_EXT | PSW_MASK_WAIT;
  45         S390_lowcore.ext_int_code = 0;
  46
  47         do {
  48                 asm volatile(
  49                         "       larl    %[addr],0f\n"
  50                         "       stg     %[addr],%[psw_wait_addr]\n"
  51                         "       stg     %[addr],%[psw_ext_addr]\n"
  52                         "       lpswe   %[psw_wait]\n"
  53                         "0:\n"
  54                         : [addr] "=&d" (addr),
  55                           [psw_wait_addr] "=Q" (psw_wait.addr),
  56                           [psw_ext_addr] "=Q" (S390_lowcore.external_new_psw.addr)
  57                         : [psw_wait] "Q" (psw_wait)
  58                         : "cc", "memory");
  59         } while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);
  60
  61         S390_lowcore.external_new_psw = psw_ext_save;
  62         local_ctl_load(0, &cr0.reg);
  63 }
  64
  65 int sclp_early_cmd(sclp_cmdw_t cmd, void *sccb)
  66 {
  67         unsigned long flags;
  68         int rc;
  69
  70         flags = arch_local_irq_save();
  71         rc = sclp_service_call(cmd, sccb);
  72         if (rc)
  73                 goto out;
  74         sclp_early_wait_irq();
  75 out:
  76         arch_local_irq_restore(flags);
  77         return rc;
  78 }
  79
  80 struct write_sccb {
  81         struct sccb_header header;
  82         struct msg_buf msg;
  83 } __packed;
  84
  85 /* Output multi-line text using SCLP Message interface. */
  86 static void sclp_early_print_lm(const char *str, unsigned int len)
  87 {
  88         unsigned char *ptr, *end, ch;
  89         unsigned int count, offset;
  90         struct write_sccb *sccb;
  91         struct msg_buf *msg;
  92         struct mdb *mdb;
  93         struct mto *mto;
  94         struct go *go;
  95
  96         sccb = (struct write_sccb *) sclp_early_sccb;
  97         end = (unsigned char *) sccb + EARLY_SCCB_SIZE - 1;
  98         memset(sccb, 0, sizeof(*sccb));
  99         ptr = (unsigned char *) &sccb->msg.mdb.mto;
 100         offset = 0;
 101         do {
 102                 for (count = sizeof(*mto); offset < len; count++) {
 103                         ch = str[offset++];
 104                         if ((ch == 0x0a) || (ptr + count > end))
 105                                 break;
 106                         ptr[count] = _ascebc[ch];
 107                 }
 108                 mto = (struct mto *) ptr;
 109                 memset(mto, 0, sizeof(*mto));
 110                 mto->length = count;
 111                 mto->type = 4;
 112                 mto->line_type_flags = LNTPFLGS_ENDTEXT;
 113                 ptr += count;
 114         } while ((offset < len) && (ptr + sizeof(*mto) <= end));
 115         len = ptr - (unsigned char *) sccb;
 116         sccb->header.length = len - offsetof(struct write_sccb, header);
 117         msg = &sccb->msg;
 118         msg->header.type = EVTYP_MSG;
 119         msg->header.length = len - offsetof(struct write_sccb, msg.header);
 120         mdb = &msg->mdb;
 121         mdb->header.type = 1;
 122         mdb->header.tag = 0xD4C4C240;
 123         mdb->header.revision_code = 1;
 124         mdb->header.length = len - offsetof(struct write_sccb, msg.mdb.header);
 125         go = &mdb->go;
 126         go->length = sizeof(*go);
 127         go->type = 1;
 128         sclp_early_cmd(SCLP_CMDW_WRITE_EVENT_DATA, sccb);
 129 }
 130
 131 struct vt220_sccb {
 132         struct sccb_header header;
 133         struct {
 134                 struct evbuf_header header;
 135                 char data[];
 136         } msg;
 137 } __packed;
 138
 139 /* Output multi-line text using SCLP VT220 interface. */
 140 static void sclp_early_print_vt220(const char *str, unsigned int len)
 141 {
 142         struct vt220_sccb *sccb;
 143
 144         sccb = (struct vt220_sccb *) sclp_early_sccb;
 145         if (sizeof(*sccb) + len >= EARLY_SCCB_SIZE)
 146                 len = EARLY_SCCB_SIZE - sizeof(*sccb);
 147         memset(sccb, 0, sizeof(*sccb));
 148         memcpy(&sccb->msg.data, str, len);
 149         sccb->header.length = sizeof(*sccb) + len;
 150         sccb->msg.header.length = sizeof(sccb->msg) + len;
 151         sccb->msg.header.type = EVTYP_VT220MSG;
 152         sclp_early_cmd(SCLP_CMDW_WRITE_EVENT_DATA, sccb);
 153 }
 154
 155 int sclp_early_set_event_mask(struct init_sccb *sccb,
 156                               sccb_mask_t receive_mask,
 157                               sccb_mask_t send_mask)
 158 {
 159 retry:
 160         memset(sccb, 0, sizeof(*sccb));
 161         sccb->header.length = sizeof(*sccb);
 162         if (sclp_mask_compat_mode)
 163                 sccb->mask_length = SCLP_MASK_SIZE_COMPAT;
 164         else
 165                 sccb->mask_length = sizeof(sccb_mask_t);
 166         sccb_set_recv_mask(sccb, receive_mask);
 167         sccb_set_send_mask(sccb, send_mask);
 168         if (sclp_early_cmd(SCLP_CMDW_WRITE_EVENT_MASK, sccb))
 169                 return -EIO;
 170         if ((sccb->header.response_code == 0x74f0) && !sclp_mask_compat_mode) {
 171                 sclp_mask_compat_mode = true;
 172                 goto retry;
 173         }
 174         if (sccb->header.response_code != 0x20)
 175                 return -EIO;
 176         return 0;
 177 }
 178
 179 unsigned int sclp_early_con_check_linemode(struct init_sccb *sccb)
 180 {
 181         if (!(sccb_get_sclp_send_mask(sccb) & EVTYP_OPCMD_MASK))
 182                 return 0;
 183         if (!(sccb_get_sclp_recv_mask(sccb) & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
 184                 return 0;
 185         return 1;
 186 }
 187
 188 unsigned int sclp_early_con_check_vt220(struct init_sccb *sccb)
 189 {
 190         if (sccb_get_sclp_send_mask(sccb) & EVTYP_VT220MSG_MASK)
 191                 return 1;
 192         return 0;
 193 }
 194
 195 static int sclp_early_setup(int disable, int *have_linemode, int *have_vt220)
 196 {
 197         unsigned long receive_mask, send_mask;
 198         struct init_sccb *sccb;
 199         int rc;
 200
 201         BUILD_BUG_ON(sizeof(struct init_sccb) > PAGE_SIZE);
 202
 203         *have_linemode = *have_vt220 = 0;
 204         sccb = (struct init_sccb *) sclp_early_sccb;
 205         receive_mask = disable ? 0 : EVTYP_OPCMD_MASK;
 206         send_mask = disable ? 0 : EVTYP_VT220MSG_MASK | EVTYP_MSG_MASK;
 207         rc = sclp_early_set_event_mask(sccb, receive_mask, send_mask);
 208         if (rc)
 209                 return rc;
 210         *have_linemode = sclp_early_con_check_linemode(sccb);
 211         *have_vt220 = !!(sccb_get_send_mask(sccb) & EVTYP_VT220MSG_MASK);
 212         return rc;
 213 }
 214
 215 void sclp_early_set_buffer(void *sccb)
 216 {
 217         sclp_early_sccb = sccb;
 218 }
 219
 220 /*
 221  * Output one or more lines of text on the SCLP console (VT220 and /
 222  * or line-mode).
 223  */
 224 void __sclp_early_printk(const char *str, unsigned int len)
 225 {
 226         int have_linemode, have_vt220;
 227
 228         if (sclp_init_state != sclp_init_state_uninitialized)
 229                 return;
 230         if (sclp_early_setup(0, &have_linemode, &have_vt220) != 0)
 231                 return;
 232         if (have_linemode)
 233                 sclp_early_print_lm(str, len);
 234         if (have_vt220)
 235                 sclp_early_print_vt220(str, len);
 236         sclp_early_setup(1, &have_linemode, &have_vt220);
 237 }
 238
 239 void sclp_early_printk(const char *str)
 240 {
 241         __sclp_early_printk(str, strlen(str));
 242 }
 243
 244 /*
 245  * Use sclp_emergency_printk() to print a string when the system is in a
 246  * state where regular console drivers cannot be assumed to work anymore.
 247  *
 248  * Callers must make sure that no concurrent SCLP requests are outstanding
 249  * and all other CPUs are stopped, or at least disabled for external
 250  * interrupts.
 251  */
 252 void sclp_emergency_printk(const char *str)
 253 {
 254         int have_linemode, have_vt220;
 255         unsigned int len;
 256
 257         len = strlen(str);
 258         /*
 259          * Don't care about return values; if requests fail, just ignore and
 260          * continue to have a rather high chance that anything is printed.
 261          */
 262         sclp_early_setup(0, &have_linemode, &have_vt220);
 263         sclp_early_print_lm(str, len);
 264         sclp_early_print_vt220(str, len);
 265         sclp_early_setup(1, &have_linemode, &have_vt220);
 266 }
 267
 268 /*
 269  * We can't pass sclp_info_sccb to sclp_early_cmd() here directly,
 270  * because it might not fulfil the requiremets for a SCLP communication buffer:
 271  *   - lie below 2G in memory
 272  *   - be page-aligned
 273  * Therefore, we use the buffer sclp_early_sccb (which fulfils all those
 274  * requirements) temporarily for communication and copy a received response
 275  * back into the buffer sclp_info_sccb upon successful completion.
 276  */
 277 int __init sclp_early_read_info(void)
 278 {
 279         int i;
 280         int length = test_facility(140) ? EXT_SCCB_READ_SCP : PAGE_SIZE;
 281         struct read_info_sccb *sccb = (struct read_info_sccb *)sclp_early_sccb;
 282         sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
 283                                   SCLP_CMDW_READ_SCP_INFO};
 284
 285         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 286                 memset(sccb, 0, length);
 287                 sccb->header.length = length;
 288                 sccb->header.function_code = 0x80;
 289                 sccb->header.control_mask[2] = 0x80;
 290                 if (sclp_early_cmd(commands[i], sccb))
 291                         break;
 292                 if (sccb->header.response_code == 0x10) {
 293                         memcpy(&sclp_info_sccb, sccb, length);
 294                         sclp_info_sccb_valid = 1;
 295                         return 0;
 296                 }
 297                 if (sccb->header.response_code != 0x1f0)
 298                         break;
 299         }
 300         return -EIO;
 301 }
 302
 303 struct read_info_sccb * __init sclp_early_get_info(void)
 304 {
 305         if (!sclp_info_sccb_valid)
 306                 return NULL;
 307
 308         return &sclp_info_sccb;
 309 }
 310
 311 int __init sclp_early_get_memsize(unsigned long *mem)
 312 {
 313         unsigned long rnmax;
 314         unsigned long rnsize;
 315         struct read_info_sccb *sccb = &sclp_info_sccb;
 316
 317         if (!sclp_info_sccb_valid)
 318                 return -EIO;
 319
 320         rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
 321         rnsize = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
 322         rnsize <<= 20;
 323         *mem = rnsize * rnmax;
 324         return 0;
 325 }
 326
 327 int __init sclp_early_get_hsa_size(unsigned long *hsa_size)
 328 {
 329         if (!sclp_info_sccb_valid)
 330                 return -EIO;
 331
 332         *hsa_size = 0;
 333         if (sclp_info_sccb.hsa_size)
 334                 *hsa_size = (sclp_info_sccb.hsa_size - 1) * PAGE_SIZE;
 335         return 0;
 336 }
 337
 338 #define SCLP_STORAGE_INFO_FACILITY     0x0000400000000000UL
 339
 340 void __weak __init add_physmem_online_range(u64 start, u64 end) {}
 341 int __init sclp_early_read_storage_info(void)
 342 {
 343         struct read_storage_sccb *sccb = (struct read_storage_sccb *)sclp_early_sccb;
 344         int rc, id, max_id = 0;
 345         unsigned long rn, rzm;
 346         sclp_cmdw_t command;
 347         u16 sn;
 348
 349         if (!sclp_info_sccb_valid)
 350                 return -EIO;
 351
 352         if (!(sclp_info_sccb.facilities & SCLP_STORAGE_INFO_FACILITY))
 353                 return -EOPNOTSUPP;
 354
 355         rzm = sclp_info_sccb.rnsize ?: sclp_info_sccb.rnsize2;
 356         rzm <<= 20;
 357
 358         for (id = 0; id <= max_id; id++) {
 359                 memset(sclp_early_sccb, 0, EARLY_SCCB_SIZE);
 360                 sccb->header.length = EARLY_SCCB_SIZE;
 361                 command = SCLP_CMDW_READ_STORAGE_INFO | (id << 8);
 362                 rc = sclp_early_cmd(command, sccb);
 363                 if (rc)
 364                         goto fail;
 365
 366                 max_id = sccb->max_id;
 367                 switch (sccb->header.response_code) {
 368                 case 0x0010:
 369                         for (sn = 0; sn < sccb->assigned; sn++) {
 370                                 if (!sccb->entries[sn])
 371                                         continue;
 372                                 rn = sccb->entries[sn] >> 16;
 373                                 add_physmem_online_range((rn - 1) * rzm, rn * rzm);
 374                         }
 375                         break;
 376                 case 0x0310:
 377                 case 0x0410:
 378                         break;
 379                 default:
 380                         goto fail;
 381                 }
 382         }
 383
 384         return 0;
 385 fail:
 386         physmem_info.range_count = 0;
 387         return -EIO;
 388 }