1 // SPDX-License-Identifier: GPL-2.0+ 2 // Copyright 2017 IBM Corp. 3 #include <linux/fs.h> 4 #include <linux/poll.h> 5 #include <linux/sched/signal.h> 6 #include <linux/eventfd.h> 7 #include <linux/uaccess.h> 8 #include <uapi/misc/ocxl.h> 9 #include <asm/reg.h> 10 #include <asm/switch_to.h> 11 #include "ocxl_internal.h" 12 13 14 #define OCXL_NUM_MINORS 256 /* Total to reserve */ 15 16 static dev_t ocxl_dev; 17 static struct class *ocxl_class; 18 static DEFINE_MUTEX(minors_idr_lock); 19 static struct idr minors_idr; 20 21 static struct ocxl_file_info *find_and_get_file_info(dev_t devno) 22 { 23 struct ocxl_file_info *info; 24 25 mutex_lock(&minors_idr_lock); 26 info = idr_find(&minors_idr, MINOR(devno)); 27 if (info) 28 get_device(&info->dev); 29 mutex_unlock(&minors_idr_lock); 30 return info; 31 } 32 33 static int allocate_minor(struct ocxl_file_info *info) 34 { 35 int minor; 36 37 mutex_lock(&minors_idr_lock); 38 minor = idr_alloc(&minors_idr, info, 0, OCXL_NUM_MINORS, GFP_KERNEL); 39 mutex_unlock(&minors_idr_lock); 40 return minor; 41 } 42 43 static void free_minor(struct ocxl_file_info *info) 44 { 45 mutex_lock(&minors_idr_lock); 46 idr_remove(&minors_idr, MINOR(info->dev.devt)); 47 mutex_unlock(&minors_idr_lock); 48 } 49 50 static int afu_open(struct inode *inode, struct file *file) 51 { 52 struct ocxl_file_info *info; 53 struct ocxl_context *ctx; 54 int rc; 55 56 pr_debug("%s for device %x\n", __func__, inode->i_rdev); 57 58 info = find_and_get_file_info(inode->i_rdev); 59 if (!info) 60 return -ENODEV; 61 62 rc = ocxl_context_alloc(&ctx, info->afu, inode->i_mapping); 63 if (rc) { 64 put_device(&info->dev); 65 return rc; 66 } 67 put_device(&info->dev); 68 file->private_data = ctx; 69 return 0; 70 } 71 72 static long afu_ioctl_attach(struct ocxl_context *ctx, 73 struct ocxl_ioctl_attach __user *uarg) 74 { 75 struct ocxl_ioctl_attach arg; 76 u64 amr = 0; 77 78 pr_debug("%s for context %d\n", __func__, ctx->pasid); 79 80 if (copy_from_user(&arg, uarg, sizeof(arg))) 81 return -EFAULT; 82 83 /* Make sure reserved fields are not set for forward compatibility */ 84 if (arg.reserved1 || arg.reserved2 || arg.reserved3) 85 return -EINVAL; 86 87 amr = arg.amr & mfspr(SPRN_UAMOR); 88 return ocxl_context_attach(ctx, amr, current->mm); 89 } 90 91 static long afu_ioctl_get_metadata(struct ocxl_context *ctx, 92 struct ocxl_ioctl_metadata __user *uarg) 93 { 94 struct ocxl_ioctl_metadata arg; 95 96 memset(&arg, 0, sizeof(arg)); 97 98 arg.version = 0; 99 100 arg.afu_version_major = ctx->afu->config.version_major; 101 arg.afu_version_minor = ctx->afu->config.version_minor; 102 arg.pasid = ctx->pasid; 103 arg.pp_mmio_size = ctx->afu->config.pp_mmio_stride; 104 arg.global_mmio_size = ctx->afu->config.global_mmio_size; 105 106 if (copy_to_user(uarg, &arg, sizeof(arg))) 107 return -EFAULT; 108 109 return 0; 110 } 111 112 #ifdef CONFIG_PPC64 113 static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx, 114 struct ocxl_ioctl_p9_wait __user *uarg) 115 { 116 struct ocxl_ioctl_p9_wait arg; 117 118 memset(&arg, 0, sizeof(arg)); 119 120 if (cpu_has_feature(CPU_FTR_P9_TIDR)) { 121 enum ocxl_context_status status; 122 123 // Locks both status & tidr 124 mutex_lock(&ctx->status_mutex); 125 if (!ctx->tidr) { 126 if (set_thread_tidr(current)) { 127 mutex_unlock(&ctx->status_mutex); 128 return -ENOENT; 129 } 130 131 ctx->tidr = current->thread.tidr; 132 } 133 134 status = ctx->status; 135 mutex_unlock(&ctx->status_mutex); 136 137 if (status == ATTACHED) { 138 int rc = ocxl_link_update_pe(ctx->afu->fn->link, 139 ctx->pasid, ctx->tidr); 140 141 if (rc) 142 return rc; 143 } 144 145 arg.thread_id = ctx->tidr; 146 } else 147 return -ENOENT; 148 149 if (copy_to_user(uarg, &arg, sizeof(arg))) 150 return -EFAULT; 151 152 return 0; 153 } 154 #endif 155 156 157 static long afu_ioctl_get_features(struct ocxl_context *ctx, 158 struct ocxl_ioctl_features __user *uarg) 159 { 160 struct ocxl_ioctl_features arg; 161 162 memset(&arg, 0, sizeof(arg)); 163 164 #ifdef CONFIG_PPC64 165 if (cpu_has_feature(CPU_FTR_P9_TIDR)) 166 arg.flags[0] |= OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT; 167 #endif 168 169 if (copy_to_user(uarg, &arg, sizeof(arg))) 170 return -EFAULT; 171 172 return 0; 173 } 174 175 #define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" : \ 176 x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" : \ 177 x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" : \ 178 x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" : \ 179 x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" : \ 180 x == OCXL_IOCTL_ENABLE_P9_WAIT ? "ENABLE_P9_WAIT" : \ 181 x == OCXL_IOCTL_GET_FEATURES ? "GET_FEATURES" : \ 182 "UNKNOWN") 183 184 static irqreturn_t irq_handler(void *private) 185 { 186 struct eventfd_ctx *ev_ctx = private; 187 188 eventfd_signal(ev_ctx, 1); 189 return IRQ_HANDLED; 190 } 191 192 static void irq_free(void *private) 193 { 194 struct eventfd_ctx *ev_ctx = private; 195 196 eventfd_ctx_put(ev_ctx); 197 } 198 199 static long afu_ioctl(struct file *file, unsigned int cmd, 200 unsigned long args) 201 { 202 struct ocxl_context *ctx = file->private_data; 203 struct ocxl_ioctl_irq_fd irq_fd; 204 struct eventfd_ctx *ev_ctx; 205 int irq_id; 206 u64 irq_offset; 207 long rc; 208 bool closed; 209 210 pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid, 211 CMD_STR(cmd)); 212 213 mutex_lock(&ctx->status_mutex); 214 closed = (ctx->status == CLOSED); 215 mutex_unlock(&ctx->status_mutex); 216 217 if (closed) 218 return -EIO; 219 220 switch (cmd) { 221 case OCXL_IOCTL_ATTACH: 222 rc = afu_ioctl_attach(ctx, 223 (struct ocxl_ioctl_attach __user *) args); 224 break; 225 226 case OCXL_IOCTL_IRQ_ALLOC: 227 rc = ocxl_afu_irq_alloc(ctx, &irq_id); 228 if (!rc) { 229 irq_offset = ocxl_irq_id_to_offset(ctx, irq_id); 230 rc = copy_to_user((u64 __user *) args, &irq_offset, 231 sizeof(irq_offset)); 232 if (rc) { 233 ocxl_afu_irq_free(ctx, irq_id); 234 return -EFAULT; 235 } 236 } 237 break; 238 239 case OCXL_IOCTL_IRQ_FREE: 240 rc = copy_from_user(&irq_offset, (u64 __user *) args, 241 sizeof(irq_offset)); 242 if (rc) 243 return -EFAULT; 244 irq_id = ocxl_irq_offset_to_id(ctx, irq_offset); 245 rc = ocxl_afu_irq_free(ctx, irq_id); 246 break; 247 248 case OCXL_IOCTL_IRQ_SET_FD: 249 rc = copy_from_user(&irq_fd, (u64 __user *) args, 250 sizeof(irq_fd)); 251 if (rc) 252 return -EFAULT; 253 if (irq_fd.reserved) 254 return -EINVAL; 255 irq_id = ocxl_irq_offset_to_id(ctx, irq_fd.irq_offset); 256 ev_ctx = eventfd_ctx_fdget(irq_fd.eventfd); 257 if (IS_ERR(ev_ctx)) 258 return PTR_ERR(ev_ctx); 259 rc = ocxl_irq_set_handler(ctx, irq_id, irq_handler, irq_free, ev_ctx); 260 break; 261 262 case OCXL_IOCTL_GET_METADATA: 263 rc = afu_ioctl_get_metadata(ctx, 264 (struct ocxl_ioctl_metadata __user *) args); 265 break; 266 267 #ifdef CONFIG_PPC64 268 case OCXL_IOCTL_ENABLE_P9_WAIT: 269 rc = afu_ioctl_enable_p9_wait(ctx, 270 (struct ocxl_ioctl_p9_wait __user *) args); 271 break; 272 #endif 273 274 case OCXL_IOCTL_GET_FEATURES: 275 rc = afu_ioctl_get_features(ctx, 276 (struct ocxl_ioctl_features __user *) args); 277 break; 278 279 default: 280 rc = -EINVAL; 281 } 282 return rc; 283 } 284 285 static long afu_compat_ioctl(struct file *file, unsigned int cmd, 286 unsigned long args) 287 { 288 return afu_ioctl(file, cmd, args); 289 } 290 291 static int afu_mmap(struct file *file, struct vm_area_struct *vma) 292 { 293 struct ocxl_context *ctx = file->private_data; 294 295 pr_debug("%s for context %d\n", __func__, ctx->pasid); 296 return ocxl_context_mmap(ctx, vma); 297 } 298 299 static bool has_xsl_error(struct ocxl_context *ctx) 300 { 301 bool ret; 302 303 mutex_lock(&ctx->xsl_error_lock); 304 ret = !!ctx->xsl_error.addr; 305 mutex_unlock(&ctx->xsl_error_lock); 306 307 return ret; 308 } 309 310 /* 311 * Are there any events pending on the AFU 312 * ctx: The AFU context 313 * Returns: true if there are events pending 314 */ 315 static bool afu_events_pending(struct ocxl_context *ctx) 316 { 317 if (has_xsl_error(ctx)) 318 return true; 319 return false; 320 } 321 322 static unsigned int afu_poll(struct file *file, struct poll_table_struct *wait) 323 { 324 struct ocxl_context *ctx = file->private_data; 325 unsigned int mask = 0; 326 bool closed; 327 328 pr_debug("%s for context %d\n", __func__, ctx->pasid); 329 330 poll_wait(file, &ctx->events_wq, wait); 331 332 mutex_lock(&ctx->status_mutex); 333 closed = (ctx->status == CLOSED); 334 mutex_unlock(&ctx->status_mutex); 335 336 if (afu_events_pending(ctx)) 337 mask = EPOLLIN | EPOLLRDNORM; 338 else if (closed) 339 mask = EPOLLERR; 340 341 return mask; 342 } 343 344 /* 345 * Populate the supplied buffer with a single XSL error 346 * ctx: The AFU context to report the error from 347 * header: the event header to populate 348 * buf: The buffer to write the body into (should be at least 349 * AFU_EVENT_BODY_XSL_ERROR_SIZE) 350 * Return: the amount of buffer that was populated 351 */ 352 static ssize_t append_xsl_error(struct ocxl_context *ctx, 353 struct ocxl_kernel_event_header *header, 354 char __user *buf) 355 { 356 struct ocxl_kernel_event_xsl_fault_error body; 357 358 memset(&body, 0, sizeof(body)); 359 360 mutex_lock(&ctx->xsl_error_lock); 361 if (!ctx->xsl_error.addr) { 362 mutex_unlock(&ctx->xsl_error_lock); 363 return 0; 364 } 365 366 body.addr = ctx->xsl_error.addr; 367 body.dsisr = ctx->xsl_error.dsisr; 368 body.count = ctx->xsl_error.count; 369 370 ctx->xsl_error.addr = 0; 371 ctx->xsl_error.dsisr = 0; 372 ctx->xsl_error.count = 0; 373 374 mutex_unlock(&ctx->xsl_error_lock); 375 376 header->type = OCXL_AFU_EVENT_XSL_FAULT_ERROR; 377 378 if (copy_to_user(buf, &body, sizeof(body))) 379 return -EFAULT; 380 381 return sizeof(body); 382 } 383 384 #define AFU_EVENT_BODY_MAX_SIZE sizeof(struct ocxl_kernel_event_xsl_fault_error) 385 386 /* 387 * Reports events on the AFU 388 * Format: 389 * Header (struct ocxl_kernel_event_header) 390 * Body (struct ocxl_kernel_event_*) 391 * Header... 392 */ 393 static ssize_t afu_read(struct file *file, char __user *buf, size_t count, 394 loff_t *off) 395 { 396 struct ocxl_context *ctx = file->private_data; 397 struct ocxl_kernel_event_header header; 398 ssize_t rc; 399 ssize_t used = 0; 400 DEFINE_WAIT(event_wait); 401 402 memset(&header, 0, sizeof(header)); 403 404 /* Require offset to be 0 */ 405 if (*off != 0) 406 return -EINVAL; 407 408 if (count < (sizeof(struct ocxl_kernel_event_header) + 409 AFU_EVENT_BODY_MAX_SIZE)) 410 return -EINVAL; 411 412 for (;;) { 413 prepare_to_wait(&ctx->events_wq, &event_wait, 414 TASK_INTERRUPTIBLE); 415 416 if (afu_events_pending(ctx)) 417 break; 418 419 if (ctx->status == CLOSED) 420 break; 421 422 if (file->f_flags & O_NONBLOCK) { 423 finish_wait(&ctx->events_wq, &event_wait); 424 return -EAGAIN; 425 } 426 427 if (signal_pending(current)) { 428 finish_wait(&ctx->events_wq, &event_wait); 429 return -ERESTARTSYS; 430 } 431 432 schedule(); 433 } 434 435 finish_wait(&ctx->events_wq, &event_wait); 436 437 if (has_xsl_error(ctx)) { 438 used = append_xsl_error(ctx, &header, buf + sizeof(header)); 439 if (used < 0) 440 return used; 441 } 442 443 if (!afu_events_pending(ctx)) 444 header.flags |= OCXL_KERNEL_EVENT_FLAG_LAST; 445 446 if (copy_to_user(buf, &header, sizeof(header))) 447 return -EFAULT; 448 449 used += sizeof(header); 450 451 rc = used; 452 return rc; 453 } 454 455 static int afu_release(struct inode *inode, struct file *file) 456 { 457 struct ocxl_context *ctx = file->private_data; 458 int rc; 459 460 pr_debug("%s for device %x\n", __func__, inode->i_rdev); 461 rc = ocxl_context_detach(ctx); 462 mutex_lock(&ctx->mapping_lock); 463 ctx->mapping = NULL; 464 mutex_unlock(&ctx->mapping_lock); 465 wake_up_all(&ctx->events_wq); 466 if (rc != -EBUSY) 467 ocxl_context_free(ctx); 468 return 0; 469 } 470 471 static const struct file_operations ocxl_afu_fops = { 472 .owner = THIS_MODULE, 473 .open = afu_open, 474 .unlocked_ioctl = afu_ioctl, 475 .compat_ioctl = afu_compat_ioctl, 476 .mmap = afu_mmap, 477 .poll = afu_poll, 478 .read = afu_read, 479 .release = afu_release, 480 }; 481 482 // Free the info struct 483 static void info_release(struct device *dev) 484 { 485 struct ocxl_file_info *info = container_of(dev, struct ocxl_file_info, dev); 486 487 ocxl_afu_put(info->afu); 488 kfree(info); 489 } 490 491 static int ocxl_file_make_visible(struct ocxl_file_info *info) 492 { 493 int rc; 494 495 cdev_init(&info->cdev, &ocxl_afu_fops); 496 rc = cdev_add(&info->cdev, info->dev.devt, 1); 497 if (rc) { 498 dev_err(&info->dev, "Unable to add afu char device: %d\n", rc); 499 return rc; 500 } 501 502 return 0; 503 } 504 505 static void ocxl_file_make_invisible(struct ocxl_file_info *info) 506 { 507 cdev_del(&info->cdev); 508 } 509 510 int ocxl_file_register_afu(struct ocxl_afu *afu) 511 { 512 int minor; 513 int rc; 514 struct ocxl_file_info *info; 515 struct ocxl_fn *fn = afu->fn; 516 struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent); 517 518 info = kzalloc(sizeof(*info), GFP_KERNEL); 519 if (info == NULL) 520 return -ENOMEM; 521 522 minor = allocate_minor(info); 523 if (minor < 0) { 524 kfree(info); 525 return minor; 526 } 527 528 info->dev.parent = &fn->dev; 529 info->dev.devt = MKDEV(MAJOR(ocxl_dev), minor); 530 info->dev.class = ocxl_class; 531 info->dev.release = info_release; 532 533 info->afu = afu; 534 ocxl_afu_get(afu); 535 536 rc = dev_set_name(&info->dev, "%s.%s.%hhu", 537 afu->config.name, dev_name(&pci_dev->dev), afu->config.idx); 538 if (rc) 539 goto err_put; 540 541 rc = device_register(&info->dev); 542 if (rc) 543 goto err_put; 544 545 rc = ocxl_sysfs_register_afu(info); 546 if (rc) 547 goto err_unregister; 548 549 rc = ocxl_file_make_visible(info); 550 if (rc) 551 goto err_unregister; 552 553 ocxl_afu_set_private(afu, info); 554 555 return 0; 556 557 err_unregister: 558 ocxl_sysfs_unregister_afu(info); // safe to call even if register failed 559 device_unregister(&info->dev); 560 err_put: 561 ocxl_afu_put(afu); 562 free_minor(info); 563 kfree(info); 564 return rc; 565 } 566 567 void ocxl_file_unregister_afu(struct ocxl_afu *afu) 568 { 569 struct ocxl_file_info *info = ocxl_afu_get_private(afu); 570 571 if (!info) 572 return; 573 574 ocxl_file_make_invisible(info); 575 ocxl_sysfs_unregister_afu(info); 576 free_minor(info); 577 device_unregister(&info->dev); 578 } 579 580 static char *ocxl_devnode(struct device *dev, umode_t *mode) 581 { 582 return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev)); 583 } 584 585 int ocxl_file_init(void) 586 { 587 int rc; 588 589 idr_init(&minors_idr); 590 591 rc = alloc_chrdev_region(&ocxl_dev, 0, OCXL_NUM_MINORS, "ocxl"); 592 if (rc) { 593 pr_err("Unable to allocate ocxl major number: %d\n", rc); 594 return rc; 595 } 596 597 ocxl_class = class_create(THIS_MODULE, "ocxl"); 598 if (IS_ERR(ocxl_class)) { 599 pr_err("Unable to create ocxl class\n"); 600 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); 601 return PTR_ERR(ocxl_class); 602 } 603 604 ocxl_class->devnode = ocxl_devnode; 605 return 0; 606 } 607 608 void ocxl_file_exit(void) 609 { 610 class_destroy(ocxl_class); 611 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); 612 idr_destroy(&minors_idr); 613 } 614