Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * drivers/s390/char/sclp_rw.c |
| 3 | * driver: reading from and writing to system console on S/390 via SCLP |
| 4 | * |
| 5 | * S390 version |
| 6 | * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| 7 | * Author(s): Martin Peschke <mpeschke@de.ibm.com> |
| 8 | * Martin Schwidefsky <schwidefsky@de.ibm.com> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/config.h> |
| 12 | #include <linux/kmod.h> |
| 13 | #include <linux/types.h> |
| 14 | #include <linux/err.h> |
| 15 | #include <linux/string.h> |
| 16 | #include <linux/spinlock.h> |
| 17 | #include <linux/ctype.h> |
| 18 | #include <asm/uaccess.h> |
| 19 | |
| 20 | #include "sclp.h" |
| 21 | #include "sclp_rw.h" |
| 22 | |
| 23 | #define SCLP_RW_PRINT_HEADER "sclp low level driver: " |
| 24 | |
| 25 | /* |
| 26 | * The room for the SCCB (only for writing) is not equal to a pages size |
Adrian Bunk | 58ef2c4 | 2006-04-01 01:04:59 +0200 | [diff] [blame] | 27 | * (as it is specified as the maximum size in the the SCLP documentation) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | * because of the additional data structure described above. |
| 29 | */ |
| 30 | #define MAX_SCCB_ROOM (PAGE_SIZE - sizeof(struct sclp_buffer)) |
| 31 | |
| 32 | /* Event type structure for write message and write priority message */ |
| 33 | static struct sclp_register sclp_rw_event = { |
| 34 | .send_mask = EvTyp_Msg_Mask | EvTyp_PMsgCmd_Mask |
| 35 | }; |
| 36 | |
| 37 | /* |
| 38 | * Setup a sclp write buffer. Gets a page as input (4K) and returns |
| 39 | * a pointer to a struct sclp_buffer structure that is located at the |
| 40 | * end of the input page. This reduces the buffer space by a few |
| 41 | * bytes but simplifies things. |
| 42 | */ |
| 43 | struct sclp_buffer * |
| 44 | sclp_make_buffer(void *page, unsigned short columns, unsigned short htab) |
| 45 | { |
| 46 | struct sclp_buffer *buffer; |
| 47 | struct write_sccb *sccb; |
| 48 | |
| 49 | sccb = (struct write_sccb *) page; |
| 50 | /* |
| 51 | * We keep the struct sclp_buffer structure at the end |
| 52 | * of the sccb page. |
| 53 | */ |
| 54 | buffer = ((struct sclp_buffer *) ((addr_t) sccb + PAGE_SIZE)) - 1; |
| 55 | buffer->sccb = sccb; |
| 56 | buffer->retry_count = 0; |
| 57 | buffer->mto_number = 0; |
| 58 | buffer->mto_char_sum = 0; |
| 59 | buffer->current_line = NULL; |
| 60 | buffer->current_length = 0; |
| 61 | buffer->columns = columns; |
| 62 | buffer->htab = htab; |
| 63 | |
| 64 | /* initialize sccb */ |
| 65 | memset(sccb, 0, sizeof(struct write_sccb)); |
| 66 | sccb->header.length = sizeof(struct write_sccb); |
| 67 | sccb->msg_buf.header.length = sizeof(struct msg_buf); |
| 68 | sccb->msg_buf.header.type = EvTyp_Msg; |
| 69 | sccb->msg_buf.mdb.header.length = sizeof(struct mdb); |
| 70 | sccb->msg_buf.mdb.header.type = 1; |
| 71 | sccb->msg_buf.mdb.header.tag = 0xD4C4C240; /* ebcdic "MDB " */ |
| 72 | sccb->msg_buf.mdb.header.revision_code = 1; |
| 73 | sccb->msg_buf.mdb.go.length = sizeof(struct go); |
| 74 | sccb->msg_buf.mdb.go.type = 1; |
| 75 | |
| 76 | return buffer; |
| 77 | } |
| 78 | |
| 79 | /* |
| 80 | * Return a pointer to the orignal page that has been used to create |
| 81 | * the buffer. |
| 82 | */ |
| 83 | void * |
| 84 | sclp_unmake_buffer(struct sclp_buffer *buffer) |
| 85 | { |
| 86 | return buffer->sccb; |
| 87 | } |
| 88 | |
| 89 | /* |
| 90 | * Initialize a new Message Text Object (MTO) at the end of the provided buffer |
| 91 | * with enough room for max_len characters. Return 0 on success. |
| 92 | */ |
| 93 | static int |
| 94 | sclp_initialize_mto(struct sclp_buffer *buffer, int max_len) |
| 95 | { |
| 96 | struct write_sccb *sccb; |
| 97 | struct mto *mto; |
| 98 | int mto_size; |
| 99 | |
| 100 | /* max size of new Message Text Object including message text */ |
| 101 | mto_size = sizeof(struct mto) + max_len; |
| 102 | |
| 103 | /* check if current buffer sccb can contain the mto */ |
| 104 | sccb = buffer->sccb; |
| 105 | if ((MAX_SCCB_ROOM - sccb->header.length) < mto_size) |
| 106 | return -ENOMEM; |
| 107 | |
| 108 | /* find address of new message text object */ |
| 109 | mto = (struct mto *)(((addr_t) sccb) + sccb->header.length); |
| 110 | |
| 111 | /* |
| 112 | * fill the new Message-Text Object, |
| 113 | * starting behind the former last byte of the SCCB |
| 114 | */ |
| 115 | memset(mto, 0, sizeof(struct mto)); |
| 116 | mto->length = sizeof(struct mto); |
| 117 | mto->type = 4; /* message text object */ |
| 118 | mto->line_type_flags = LnTpFlgs_EndText; /* end text */ |
| 119 | |
| 120 | /* set pointer to first byte after struct mto. */ |
| 121 | buffer->current_line = (char *) (mto + 1); |
| 122 | buffer->current_length = 0; |
| 123 | |
| 124 | return 0; |
| 125 | } |
| 126 | |
| 127 | /* |
| 128 | * Finalize MTO initialized by sclp_initialize_mto(), updating the sizes of |
| 129 | * MTO, enclosing MDB, event buffer and SCCB. |
| 130 | */ |
| 131 | static void |
| 132 | sclp_finalize_mto(struct sclp_buffer *buffer) |
| 133 | { |
| 134 | struct write_sccb *sccb; |
| 135 | struct mto *mto; |
| 136 | int str_len, mto_size; |
| 137 | |
| 138 | str_len = buffer->current_length; |
| 139 | buffer->current_line = NULL; |
| 140 | buffer->current_length = 0; |
| 141 | |
| 142 | /* real size of new Message Text Object including message text */ |
| 143 | mto_size = sizeof(struct mto) + str_len; |
| 144 | |
| 145 | /* find address of new message text object */ |
| 146 | sccb = buffer->sccb; |
| 147 | mto = (struct mto *)(((addr_t) sccb) + sccb->header.length); |
| 148 | |
| 149 | /* set size of message text object */ |
| 150 | mto->length = mto_size; |
| 151 | |
| 152 | /* |
| 153 | * update values of sizes |
| 154 | * (SCCB, Event(Message) Buffer, Message Data Block) |
| 155 | */ |
| 156 | sccb->header.length += mto_size; |
| 157 | sccb->msg_buf.header.length += mto_size; |
| 158 | sccb->msg_buf.mdb.header.length += mto_size; |
| 159 | |
| 160 | /* |
| 161 | * count number of buffered messages (= number of Message Text |
| 162 | * Objects) and number of buffered characters |
| 163 | * for the SCCB currently used for buffering and at all |
| 164 | */ |
| 165 | buffer->mto_number++; |
| 166 | buffer->mto_char_sum += str_len; |
| 167 | } |
| 168 | |
| 169 | /* |
| 170 | * processing of a message including escape characters, |
| 171 | * returns number of characters written to the output sccb |
| 172 | * ("processed" means that is not guaranteed that the character have already |
| 173 | * been sent to the SCLP but that it will be done at least next time the SCLP |
| 174 | * is not busy) |
| 175 | */ |
| 176 | int |
| 177 | sclp_write(struct sclp_buffer *buffer, const unsigned char *msg, int count) |
| 178 | { |
| 179 | int spaces, i_msg; |
| 180 | int rc; |
| 181 | |
| 182 | /* |
| 183 | * parse msg for escape sequences (\t,\v ...) and put formated |
| 184 | * msg into an mto (created by sclp_initialize_mto). |
| 185 | * |
| 186 | * We have to do this work ourselfs because there is no support for |
| 187 | * these characters on the native machine and only partial support |
| 188 | * under VM (Why does VM interpret \n but the native machine doesn't ?) |
| 189 | * |
| 190 | * Depending on i/o-control setting the message is always written |
| 191 | * immediately or we wait for a final new line maybe coming with the |
| 192 | * next message. Besides we avoid a buffer overrun by writing its |
| 193 | * content. |
| 194 | * |
| 195 | * RESTRICTIONS: |
| 196 | * |
| 197 | * \r and \b work within one line because we are not able to modify |
| 198 | * previous output that have already been accepted by the SCLP. |
| 199 | * |
| 200 | * \t combined with following \r is not correctly represented because |
| 201 | * \t is expanded to some spaces but \r does not know about a |
| 202 | * previous \t and decreases the current position by one column. |
| 203 | * This is in order to a slim and quick implementation. |
| 204 | */ |
| 205 | for (i_msg = 0; i_msg < count; i_msg++) { |
| 206 | switch (msg[i_msg]) { |
| 207 | case '\n': /* new line, line feed (ASCII) */ |
| 208 | /* check if new mto needs to be created */ |
| 209 | if (buffer->current_line == NULL) { |
| 210 | rc = sclp_initialize_mto(buffer, 0); |
| 211 | if (rc) |
| 212 | return i_msg; |
| 213 | } |
| 214 | sclp_finalize_mto(buffer); |
| 215 | break; |
| 216 | case '\a': /* bell, one for several times */ |
| 217 | /* set SCLP sound alarm bit in General Object */ |
| 218 | buffer->sccb->msg_buf.mdb.go.general_msg_flags |= |
| 219 | GnrlMsgFlgs_SndAlrm; |
| 220 | break; |
| 221 | case '\t': /* horizontal tabulator */ |
| 222 | /* check if new mto needs to be created */ |
| 223 | if (buffer->current_line == NULL) { |
| 224 | rc = sclp_initialize_mto(buffer, |
| 225 | buffer->columns); |
| 226 | if (rc) |
| 227 | return i_msg; |
| 228 | } |
| 229 | /* "go to (next htab-boundary + 1, same line)" */ |
| 230 | do { |
| 231 | if (buffer->current_length >= buffer->columns) |
| 232 | break; |
| 233 | /* ok, add a blank */ |
| 234 | *buffer->current_line++ = 0x40; |
| 235 | buffer->current_length++; |
| 236 | } while (buffer->current_length % buffer->htab); |
| 237 | break; |
| 238 | case '\f': /* form feed */ |
| 239 | case '\v': /* vertical tabulator */ |
| 240 | /* "go to (actual column, actual line + 1)" */ |
| 241 | /* = new line, leading spaces */ |
| 242 | if (buffer->current_line != NULL) { |
| 243 | spaces = buffer->current_length; |
| 244 | sclp_finalize_mto(buffer); |
| 245 | rc = sclp_initialize_mto(buffer, |
| 246 | buffer->columns); |
| 247 | if (rc) |
| 248 | return i_msg; |
| 249 | memset(buffer->current_line, 0x40, spaces); |
| 250 | buffer->current_line += spaces; |
| 251 | buffer->current_length = spaces; |
| 252 | } else { |
| 253 | /* one an empty line this is the same as \n */ |
| 254 | rc = sclp_initialize_mto(buffer, |
| 255 | buffer->columns); |
| 256 | if (rc) |
| 257 | return i_msg; |
| 258 | sclp_finalize_mto(buffer); |
| 259 | } |
| 260 | break; |
| 261 | case '\b': /* backspace */ |
| 262 | /* "go to (actual column - 1, actual line)" */ |
| 263 | /* decrement counter indicating position, */ |
| 264 | /* do not remove last character */ |
| 265 | if (buffer->current_line != NULL && |
| 266 | buffer->current_length > 0) { |
| 267 | buffer->current_length--; |
| 268 | buffer->current_line--; |
| 269 | } |
| 270 | break; |
| 271 | case 0x00: /* end of string */ |
| 272 | /* transfer current line to SCCB */ |
| 273 | if (buffer->current_line != NULL) |
| 274 | sclp_finalize_mto(buffer); |
| 275 | /* skip the rest of the message including the 0 byte */ |
| 276 | i_msg = count - 1; |
| 277 | break; |
| 278 | default: /* no escape character */ |
| 279 | /* do not output unprintable characters */ |
| 280 | if (!isprint(msg[i_msg])) |
| 281 | break; |
| 282 | /* check if new mto needs to be created */ |
| 283 | if (buffer->current_line == NULL) { |
| 284 | rc = sclp_initialize_mto(buffer, |
| 285 | buffer->columns); |
| 286 | if (rc) |
| 287 | return i_msg; |
| 288 | } |
| 289 | *buffer->current_line++ = sclp_ascebc(msg[i_msg]); |
| 290 | buffer->current_length++; |
| 291 | break; |
| 292 | } |
| 293 | /* check if current mto is full */ |
| 294 | if (buffer->current_line != NULL && |
| 295 | buffer->current_length >= buffer->columns) |
| 296 | sclp_finalize_mto(buffer); |
| 297 | } |
| 298 | |
| 299 | /* return number of processed characters */ |
| 300 | return i_msg; |
| 301 | } |
| 302 | |
| 303 | /* |
| 304 | * Return the number of free bytes in the sccb |
| 305 | */ |
| 306 | int |
| 307 | sclp_buffer_space(struct sclp_buffer *buffer) |
| 308 | { |
| 309 | int count; |
| 310 | |
| 311 | count = MAX_SCCB_ROOM - buffer->sccb->header.length; |
| 312 | if (buffer->current_line != NULL) |
| 313 | count -= sizeof(struct mto) + buffer->current_length; |
| 314 | return count; |
| 315 | } |
| 316 | |
| 317 | /* |
| 318 | * Return number of characters in buffer |
| 319 | */ |
| 320 | int |
| 321 | sclp_chars_in_buffer(struct sclp_buffer *buffer) |
| 322 | { |
| 323 | int count; |
| 324 | |
| 325 | count = buffer->mto_char_sum; |
| 326 | if (buffer->current_line != NULL) |
| 327 | count += buffer->current_length; |
| 328 | return count; |
| 329 | } |
| 330 | |
| 331 | /* |
| 332 | * sets or provides some values that influence the drivers behaviour |
| 333 | */ |
| 334 | void |
| 335 | sclp_set_columns(struct sclp_buffer *buffer, unsigned short columns) |
| 336 | { |
| 337 | buffer->columns = columns; |
| 338 | if (buffer->current_line != NULL && |
| 339 | buffer->current_length > buffer->columns) |
| 340 | sclp_finalize_mto(buffer); |
| 341 | } |
| 342 | |
| 343 | void |
| 344 | sclp_set_htab(struct sclp_buffer *buffer, unsigned short htab) |
| 345 | { |
| 346 | buffer->htab = htab; |
| 347 | } |
| 348 | |
| 349 | /* |
| 350 | * called by sclp_console_init and/or sclp_tty_init |
| 351 | */ |
| 352 | int |
| 353 | sclp_rw_init(void) |
| 354 | { |
| 355 | static int init_done = 0; |
| 356 | int rc; |
| 357 | |
| 358 | if (init_done) |
| 359 | return 0; |
| 360 | |
| 361 | rc = sclp_register(&sclp_rw_event); |
| 362 | if (rc == 0) |
| 363 | init_done = 1; |
| 364 | return rc; |
| 365 | } |
| 366 | |
| 367 | #define SCLP_BUFFER_MAX_RETRY 1 |
| 368 | |
| 369 | /* |
| 370 | * second half of Write Event Data-function that has to be done after |
| 371 | * interruption indicating completion of Service Call. |
| 372 | */ |
| 373 | static void |
| 374 | sclp_writedata_callback(struct sclp_req *request, void *data) |
| 375 | { |
| 376 | int rc; |
| 377 | struct sclp_buffer *buffer; |
| 378 | struct write_sccb *sccb; |
| 379 | |
| 380 | buffer = (struct sclp_buffer *) data; |
| 381 | sccb = buffer->sccb; |
| 382 | |
| 383 | if (request->status == SCLP_REQ_FAILED) { |
| 384 | if (buffer->callback != NULL) |
| 385 | buffer->callback(buffer, -EIO); |
| 386 | return; |
| 387 | } |
| 388 | /* check SCLP response code and choose suitable action */ |
| 389 | switch (sccb->header.response_code) { |
| 390 | case 0x0020 : |
| 391 | /* Normal completion, buffer processed, message(s) sent */ |
| 392 | rc = 0; |
| 393 | break; |
| 394 | |
| 395 | case 0x0340: /* Contained SCLP equipment check */ |
| 396 | if (++buffer->retry_count > SCLP_BUFFER_MAX_RETRY) { |
| 397 | rc = -EIO; |
| 398 | break; |
| 399 | } |
| 400 | /* remove processed buffers and requeue rest */ |
| 401 | if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { |
| 402 | /* not all buffers were processed */ |
| 403 | sccb->header.response_code = 0x0000; |
| 404 | buffer->request.status = SCLP_REQ_FILLED; |
| 405 | rc = sclp_add_request(request); |
| 406 | if (rc == 0) |
| 407 | return; |
| 408 | } else |
| 409 | rc = 0; |
| 410 | break; |
| 411 | |
| 412 | case 0x0040: /* SCLP equipment check */ |
| 413 | case 0x05f0: /* Target resource in improper state */ |
| 414 | if (++buffer->retry_count > SCLP_BUFFER_MAX_RETRY) { |
| 415 | rc = -EIO; |
| 416 | break; |
| 417 | } |
| 418 | /* retry request */ |
| 419 | sccb->header.response_code = 0x0000; |
| 420 | buffer->request.status = SCLP_REQ_FILLED; |
| 421 | rc = sclp_add_request(request); |
| 422 | if (rc == 0) |
| 423 | return; |
| 424 | break; |
| 425 | default: |
| 426 | if (sccb->header.response_code == 0x71f0) |
| 427 | rc = -ENOMEM; |
| 428 | else |
| 429 | rc = -EINVAL; |
| 430 | break; |
| 431 | } |
| 432 | if (buffer->callback != NULL) |
| 433 | buffer->callback(buffer, rc); |
| 434 | } |
| 435 | |
| 436 | /* |
| 437 | * Setup the request structure in the struct sclp_buffer to do SCLP Write |
| 438 | * Event Data and pass the request to the core SCLP loop. Return zero on |
| 439 | * success, non-zero otherwise. |
| 440 | */ |
| 441 | int |
| 442 | sclp_emit_buffer(struct sclp_buffer *buffer, |
| 443 | void (*callback)(struct sclp_buffer *, int)) |
| 444 | { |
| 445 | struct write_sccb *sccb; |
| 446 | |
| 447 | /* add current line if there is one */ |
| 448 | if (buffer->current_line != NULL) |
| 449 | sclp_finalize_mto(buffer); |
| 450 | |
| 451 | /* Are there messages in the output buffer ? */ |
| 452 | if (buffer->mto_number == 0) |
| 453 | return -EIO; |
| 454 | |
| 455 | sccb = buffer->sccb; |
| 456 | if (sclp_rw_event.sclp_send_mask & EvTyp_Msg_Mask) |
| 457 | /* Use normal write message */ |
| 458 | sccb->msg_buf.header.type = EvTyp_Msg; |
| 459 | else if (sclp_rw_event.sclp_send_mask & EvTyp_PMsgCmd_Mask) |
| 460 | /* Use write priority message */ |
| 461 | sccb->msg_buf.header.type = EvTyp_PMsgCmd; |
| 462 | else |
| 463 | return -ENOSYS; |
| 464 | buffer->request.command = SCLP_CMDW_WRITEDATA; |
| 465 | buffer->request.status = SCLP_REQ_FILLED; |
| 466 | buffer->request.callback = sclp_writedata_callback; |
| 467 | buffer->request.callback_data = buffer; |
| 468 | buffer->request.sccb = sccb; |
| 469 | buffer->callback = callback; |
| 470 | return sclp_add_request(&buffer->request); |
| 471 | } |