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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 | // SPDX-License-Identifier: GPL-2.0-only /* * SCOM FSI Client device driver * * Copyright (C) IBM Corporation 2016 */ #include <linux/fsi.h> #include <linux/module.h> #include <linux/cdev.h> #include <linux/delay.h> #include <linux/fs.h> #include <linux/uaccess.h> #include <linux/slab.h> #include <linux/list.h> #include <uapi/linux/fsi.h> #define FSI_ENGID_SCOM 0x5 /* SCOM engine register set */ #define SCOM_DATA0_REG 0x00 #define SCOM_DATA1_REG 0x04 #define SCOM_CMD_REG 0x08 #define SCOM_FSI2PIB_RESET_REG 0x18 #define SCOM_STATUS_REG 0x1C /* Read */ #define SCOM_PIB_RESET_REG 0x1C /* Write */ /* Command register */ #define SCOM_WRITE_CMD 0x80000000 #define SCOM_READ_CMD 0x00000000 /* Status register bits */ #define SCOM_STATUS_ERR_SUMMARY 0x80000000 #define SCOM_STATUS_PROTECTION 0x01000000 #define SCOM_STATUS_PARITY 0x04000000 #define SCOM_STATUS_PIB_ABORT 0x00100000 #define SCOM_STATUS_PIB_RESP_MASK 0x00007000 #define SCOM_STATUS_PIB_RESP_SHIFT 12 #define SCOM_STATUS_FSI2PIB_ERROR (SCOM_STATUS_PROTECTION | \ SCOM_STATUS_PARITY | \ SCOM_STATUS_PIB_ABORT) #define SCOM_STATUS_ANY_ERR (SCOM_STATUS_FSI2PIB_ERROR | \ SCOM_STATUS_PIB_RESP_MASK) /* SCOM address encodings */ #define XSCOM_ADDR_IND_FLAG BIT_ULL(63) #define XSCOM_ADDR_INF_FORM1 BIT_ULL(60) /* SCOM indirect stuff */ #define XSCOM_ADDR_DIRECT_PART 0x7fffffffull #define XSCOM_ADDR_INDIRECT_PART 0x000fffff00000000ull #define XSCOM_DATA_IND_READ BIT_ULL(63) #define XSCOM_DATA_IND_COMPLETE BIT_ULL(31) #define XSCOM_DATA_IND_ERR_MASK 0x70000000ull #define XSCOM_DATA_IND_ERR_SHIFT 28 #define XSCOM_DATA_IND_DATA 0x0000ffffull #define XSCOM_DATA_IND_FORM1_DATA 0x000fffffffffffffull #define XSCOM_ADDR_FORM1_LOW 0x000ffffffffull #define XSCOM_ADDR_FORM1_HI 0xfff00000000ull #define XSCOM_ADDR_FORM1_HI_SHIFT 20 /* Retries */ #define SCOM_MAX_IND_RETRIES 10 /* Retries indirect not ready */ struct scom_device { struct list_head link; struct fsi_device *fsi_dev; struct device dev; struct cdev cdev; struct mutex lock; bool dead; }; static int __put_scom(struct scom_device *scom_dev, uint64_t value, uint32_t addr, uint32_t *status) { __be32 data, raw_status; int rc; data = cpu_to_be32((value >> 32) & 0xffffffff); rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data, sizeof(uint32_t)); if (rc) return rc; data = cpu_to_be32(value & 0xffffffff); rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA1_REG, &data, sizeof(uint32_t)); if (rc) return rc; data = cpu_to_be32(SCOM_WRITE_CMD | addr); rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data, sizeof(uint32_t)); if (rc) return rc; rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status, sizeof(uint32_t)); if (rc) return rc; *status = be32_to_cpu(raw_status); return 0; } static int __get_scom(struct scom_device *scom_dev, uint64_t *value, uint32_t addr, uint32_t *status) { __be32 data, raw_status; int rc; *value = 0ULL; data = cpu_to_be32(SCOM_READ_CMD | addr); rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data, sizeof(uint32_t)); if (rc) return rc; rc = fsi_device_read(scom_dev->fsi_dev, SCOM_STATUS_REG, &raw_status, sizeof(uint32_t)); if (rc) return rc; /* * Read the data registers even on error, so we don't have * to interpret the status register here. */ rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &data, sizeof(uint32_t)); if (rc) return rc; *value |= (uint64_t)be32_to_cpu(data) << 32; rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &data, sizeof(uint32_t)); if (rc) return rc; *value |= be32_to_cpu(data); *status = be32_to_cpu(raw_status); return rc; } static int put_indirect_scom_form0(struct scom_device *scom, uint64_t value, uint64_t addr, uint32_t *status) { uint64_t ind_data, ind_addr; int rc, err; if (value & ~XSCOM_DATA_IND_DATA) return -EINVAL; ind_addr = addr & XSCOM_ADDR_DIRECT_PART; ind_data = (addr & XSCOM_ADDR_INDIRECT_PART) | value; rc = __put_scom(scom, ind_data, ind_addr, status); if (rc || (*status & SCOM_STATUS_ANY_ERR)) return rc; rc = __get_scom(scom, &ind_data, addr, status); if (rc || (*status & SCOM_STATUS_ANY_ERR)) return rc; err = (ind_data & XSCOM_DATA_IND_ERR_MASK) >> XSCOM_DATA_IND_ERR_SHIFT; *status = err << SCOM_STATUS_PIB_RESP_SHIFT; return 0; } static int put_indirect_scom_form1(struct scom_device *scom, uint64_t value, uint64_t addr, uint32_t *status) { uint64_t ind_data, ind_addr; if (value & ~XSCOM_DATA_IND_FORM1_DATA) return -EINVAL; ind_addr = addr & XSCOM_ADDR_FORM1_LOW; ind_data = value | (addr & XSCOM_ADDR_FORM1_HI) << XSCOM_ADDR_FORM1_HI_SHIFT; return __put_scom(scom, ind_data, ind_addr, status); } static int get_indirect_scom_form0(struct scom_device *scom, uint64_t *value, uint64_t addr, uint32_t *status) { uint64_t ind_data, ind_addr; int rc, err; ind_addr = addr & XSCOM_ADDR_DIRECT_PART; ind_data = (addr & XSCOM_ADDR_INDIRECT_PART) | XSCOM_DATA_IND_READ; rc = __put_scom(scom, ind_data, ind_addr, status); if (rc || (*status & SCOM_STATUS_ANY_ERR)) return rc; rc = __get_scom(scom, &ind_data, addr, status); if (rc || (*status & SCOM_STATUS_ANY_ERR)) return rc; err = (ind_data & XSCOM_DATA_IND_ERR_MASK) >> XSCOM_DATA_IND_ERR_SHIFT; *status = err << SCOM_STATUS_PIB_RESP_SHIFT; *value = ind_data & XSCOM_DATA_IND_DATA; return 0; } static int raw_put_scom(struct scom_device *scom, uint64_t value, uint64_t addr, uint32_t *status) { if (addr & XSCOM_ADDR_IND_FLAG) { if (addr & XSCOM_ADDR_INF_FORM1) return put_indirect_scom_form1(scom, value, addr, status); else return put_indirect_scom_form0(scom, value, addr, status); } else return __put_scom(scom, value, addr, status); } static int raw_get_scom(struct scom_device *scom, uint64_t *value, uint64_t addr, uint32_t *status) { if (addr & XSCOM_ADDR_IND_FLAG) { if (addr & XSCOM_ADDR_INF_FORM1) return -ENXIO; return get_indirect_scom_form0(scom, value, addr, status); } else return __get_scom(scom, value, addr, status); } static int handle_fsi2pib_status(struct scom_device *scom, uint32_t status) { uint32_t dummy = -1; if (status & SCOM_STATUS_FSI2PIB_ERROR) fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy, sizeof(uint32_t)); if (status & SCOM_STATUS_PROTECTION) return -EPERM; if (status & SCOM_STATUS_PARITY) return -EIO; if (status & SCOM_STATUS_PIB_ABORT) return -EBUSY; return 0; } static int handle_pib_status(struct scom_device *scom, uint8_t status) { uint32_t dummy = -1; if (status == SCOM_PIB_SUCCESS) return 0; if (status == SCOM_PIB_BLOCKED) return -EBUSY; /* Reset the bridge */ fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy, sizeof(uint32_t)); switch(status) { case SCOM_PIB_OFFLINE: return -ENODEV; case SCOM_PIB_BAD_ADDR: return -ENXIO; case SCOM_PIB_TIMEOUT: return -ETIMEDOUT; case SCOM_PIB_PARTIAL: case SCOM_PIB_CLK_ERR: case SCOM_PIB_PARITY_ERR: default: return -EIO; } } static int put_scom(struct scom_device *scom, uint64_t value, uint64_t addr) { uint32_t status; int rc; rc = raw_put_scom(scom, value, addr, &status); if (rc) return rc; rc = handle_fsi2pib_status(scom, status); if (rc) return rc; return handle_pib_status(scom, (status & SCOM_STATUS_PIB_RESP_MASK) >> SCOM_STATUS_PIB_RESP_SHIFT); } static int get_scom(struct scom_device *scom, uint64_t *value, uint64_t addr) { uint32_t status; int rc; rc = raw_get_scom(scom, value, addr, &status); if (rc) return rc; rc = handle_fsi2pib_status(scom, status); if (rc) return rc; return handle_pib_status(scom, (status & SCOM_STATUS_PIB_RESP_MASK) >> SCOM_STATUS_PIB_RESP_SHIFT); } static ssize_t scom_read(struct file *filep, char __user *buf, size_t len, loff_t *offset) { struct scom_device *scom = filep->private_data; struct device *dev = &scom->fsi_dev->dev; uint64_t val; int rc; if (len != sizeof(uint64_t)) return -EINVAL; mutex_lock(&scom->lock); if (scom->dead) rc = -ENODEV; else rc = get_scom(scom, &val, *offset); mutex_unlock(&scom->lock); if (rc) { dev_dbg(dev, "get_scom fail:%d\n", rc); return rc; } rc = copy_to_user(buf, &val, len); if (rc) dev_dbg(dev, "copy to user failed:%d\n", rc); return rc ? rc : len; } static ssize_t scom_write(struct file *filep, const char __user *buf, size_t len, loff_t *offset) { int rc; struct scom_device *scom = filep->private_data; struct device *dev = &scom->fsi_dev->dev; uint64_t val; if (len != sizeof(uint64_t)) return -EINVAL; rc = copy_from_user(&val, buf, len); if (rc) { dev_dbg(dev, "copy from user failed:%d\n", rc); return -EINVAL; } mutex_lock(&scom->lock); if (scom->dead) rc = -ENODEV; else rc = put_scom(scom, val, *offset); mutex_unlock(&scom->lock); if (rc) { dev_dbg(dev, "put_scom failed with:%d\n", rc); return rc; } return len; } static loff_t scom_llseek(struct file *file, loff_t offset, int whence) { switch (whence) { case SEEK_CUR: break; case SEEK_SET: file->f_pos = offset; break; default: return -EINVAL; } return offset; } static void raw_convert_status(struct scom_access *acc, uint32_t status) { acc->pib_status = (status & SCOM_STATUS_PIB_RESP_MASK) >> SCOM_STATUS_PIB_RESP_SHIFT; acc->intf_errors = 0; if (status & SCOM_STATUS_PROTECTION) acc->intf_errors |= SCOM_INTF_ERR_PROTECTION; else if (status & SCOM_STATUS_PARITY) acc->intf_errors |= SCOM_INTF_ERR_PARITY; else if (status & SCOM_STATUS_PIB_ABORT) acc->intf_errors |= SCOM_INTF_ERR_ABORT; else if (status & SCOM_STATUS_ERR_SUMMARY) acc->intf_errors |= SCOM_INTF_ERR_UNKNOWN; } static int scom_raw_read(struct scom_device *scom, void __user *argp) { struct scom_access acc; uint32_t status; int rc; if (copy_from_user(&acc, argp, sizeof(struct scom_access))) return -EFAULT; rc = raw_get_scom(scom, &acc.data, acc.addr, &status); if (rc) return rc; raw_convert_status(&acc, status); if (copy_to_user(argp, &acc, sizeof(struct scom_access))) return -EFAULT; return 0; } static int scom_raw_write(struct scom_device *scom, void __user *argp) { u64 prev_data, mask, data; struct scom_access acc; uint32_t status; int rc; if (copy_from_user(&acc, argp, sizeof(struct scom_access))) return -EFAULT; if (acc.mask) { rc = raw_get_scom(scom, &prev_data, acc.addr, &status); if (rc) return rc; if (status & SCOM_STATUS_ANY_ERR) goto fail; mask = acc.mask; } else { prev_data = mask = -1ull; } data = (prev_data & ~mask) | (acc.data & mask); rc = raw_put_scom(scom, data, acc.addr, &status); if (rc) return rc; fail: raw_convert_status(&acc, status); if (copy_to_user(argp, &acc, sizeof(struct scom_access))) return -EFAULT; return 0; } static int scom_reset(struct scom_device *scom, void __user *argp) { uint32_t flags, dummy = -1; int rc = 0; if (get_user(flags, (__u32 __user *)argp)) return -EFAULT; if (flags & SCOM_RESET_PIB) rc = fsi_device_write(scom->fsi_dev, SCOM_PIB_RESET_REG, &dummy, sizeof(uint32_t)); if (!rc && (flags & (SCOM_RESET_PIB | SCOM_RESET_INTF))) rc = fsi_device_write(scom->fsi_dev, SCOM_FSI2PIB_RESET_REG, &dummy, sizeof(uint32_t)); return rc; } static int scom_check(struct scom_device *scom, void __user *argp) { /* Still need to find out how to get "protected" */ return put_user(SCOM_CHECK_SUPPORTED, (__u32 __user *)argp); } static long scom_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct scom_device *scom = file->private_data; void __user *argp = (void __user *)arg; int rc = -ENOTTY; mutex_lock(&scom->lock); if (scom->dead) { mutex_unlock(&scom->lock); return -ENODEV; } switch(cmd) { case FSI_SCOM_CHECK: rc = scom_check(scom, argp); break; case FSI_SCOM_READ: rc = scom_raw_read(scom, argp); break; case FSI_SCOM_WRITE: rc = scom_raw_write(scom, argp); break; case FSI_SCOM_RESET: rc = scom_reset(scom, argp); break; } mutex_unlock(&scom->lock); return rc; } static int scom_open(struct inode *inode, struct file *file) { struct scom_device *scom = container_of(inode->i_cdev, struct scom_device, cdev); file->private_data = scom; return 0; } static const struct file_operations scom_fops = { .owner = THIS_MODULE, .open = scom_open, .llseek = scom_llseek, .read = scom_read, .write = scom_write, .unlocked_ioctl = scom_ioctl, }; static void scom_free(struct device *dev) { struct scom_device *scom = container_of(dev, struct scom_device, dev); put_device(&scom->fsi_dev->dev); kfree(scom); } static int scom_probe(struct device *dev) { struct fsi_device *fsi_dev = to_fsi_dev(dev); struct scom_device *scom; int rc, didx; scom = kzalloc(sizeof(*scom), GFP_KERNEL); if (!scom) return -ENOMEM; dev_set_drvdata(dev, scom); mutex_init(&scom->lock); /* Grab a reference to the device (parent of our cdev), we'll drop it later */ if (!get_device(dev)) { kfree(scom); return -ENODEV; } scom->fsi_dev = fsi_dev; /* Create chardev for userspace access */ scom->dev.type = &fsi_cdev_type; scom->dev.parent = dev; scom->dev.release = scom_free; device_initialize(&scom->dev); /* Allocate a minor in the FSI space */ rc = fsi_get_new_minor(fsi_dev, fsi_dev_scom, &scom->dev.devt, &didx); if (rc) goto err; dev_set_name(&scom->dev, "scom%d", didx); cdev_init(&scom->cdev, &scom_fops); rc = cdev_device_add(&scom->cdev, &scom->dev); if (rc) { dev_err(dev, "Error %d creating char device %s\n", rc, dev_name(&scom->dev)); goto err_free_minor; } return 0; err_free_minor: fsi_free_minor(scom->dev.devt); err: put_device(&scom->dev); return rc; } static int scom_remove(struct device *dev) { struct scom_device *scom = dev_get_drvdata(dev); mutex_lock(&scom->lock); scom->dead = true; mutex_unlock(&scom->lock); cdev_device_del(&scom->cdev, &scom->dev); fsi_free_minor(scom->dev.devt); put_device(&scom->dev); return 0; } static const struct fsi_device_id scom_ids[] = { { .engine_type = FSI_ENGID_SCOM, .version = FSI_VERSION_ANY, }, { 0 } }; static struct fsi_driver scom_drv = { .id_table = scom_ids, .drv = { .name = "scom", .bus = &fsi_bus_type, .probe = scom_probe, .remove = scom_remove, } }; static int scom_init(void) { return fsi_driver_register(&scom_drv); } static void scom_exit(void) { fsi_driver_unregister(&scom_drv); } module_init(scom_init); module_exit(scom_exit); MODULE_LICENSE("GPL"); |