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 struct mutex minors_idr_lock; 19 static struct idr minors_idr; 20 21 static struct ocxl_file_info *find_file_info(dev_t devno) 22 { 23 struct ocxl_file_info *info; 24 25 /* 26 * We don't declare an RCU critical section here, as our AFU 27 * is protected by a reference counter on the device. By the time the 28 * info reference is removed from the idr, the ref count of 29 * the device is already at 0, so no user API will access that AFU and 30 * this function can't return it. 31 */ 32 info = idr_find(&minors_idr, MINOR(devno)); 33 return info; 34 } 35 36 static int allocate_minor(struct ocxl_file_info *info) 37 { 38 int minor; 39 40 mutex_lock(&minors_idr_lock); 41 minor = idr_alloc(&minors_idr, info, 0, OCXL_NUM_MINORS, GFP_KERNEL); 42 mutex_unlock(&minors_idr_lock); 43 return minor; 44 } 45 46 static void free_minor(struct ocxl_file_info *info) 47 { 48 mutex_lock(&minors_idr_lock); 49 idr_remove(&minors_idr, MINOR(info->dev.devt)); 50 mutex_unlock(&minors_idr_lock); 51 } 52 53 static int afu_open(struct inode *inode, struct file *file) 54 { 55 struct ocxl_file_info *info; 56 struct ocxl_context *ctx; 57 int rc; 58 59 pr_debug("%s for device %x\n", __func__, inode->i_rdev); 60 61 info = find_file_info(inode->i_rdev); 62 if (!info) 63 return -ENODEV; 64 65 rc = ocxl_context_alloc(&ctx, info->afu, inode->i_mapping); 66 if (rc) 67 return rc; 68 69 file->private_data = ctx; 70 return 0; 71 } 72 73 static long afu_ioctl_attach(struct ocxl_context *ctx, 74 struct ocxl_ioctl_attach __user *uarg) 75 { 76 struct ocxl_ioctl_attach arg; 77 u64 amr = 0; 78 int rc; 79 80 pr_debug("%s for context %d\n", __func__, ctx->pasid); 81 82 if (copy_from_user(&arg, uarg, sizeof(arg))) 83 return -EFAULT; 84 85 /* Make sure reserved fields are not set for forward compatibility */ 86 if (arg.reserved1 || arg.reserved2 || arg.reserved3) 87 return -EINVAL; 88 89 amr = arg.amr & mfspr(SPRN_UAMOR); 90 rc = ocxl_context_attach(ctx, amr, current->mm); 91 return rc; 92 } 93 94 static long afu_ioctl_get_metadata(struct ocxl_context *ctx, 95 struct ocxl_ioctl_metadata __user *uarg) 96 { 97 struct ocxl_ioctl_metadata arg; 98 99 memset(&arg, 0, sizeof(arg)); 100 101 arg.version = 0; 102 103 arg.afu_version_major = ctx->afu->config.version_major; 104 arg.afu_version_minor = ctx->afu->config.version_minor; 105 arg.pasid = ctx->pasid; 106 arg.pp_mmio_size = ctx->afu->config.pp_mmio_stride; 107 arg.global_mmio_size = ctx->afu->config.global_mmio_size; 108 109 if (copy_to_user(uarg, &arg, sizeof(arg))) 110 return -EFAULT; 111 112 return 0; 113 } 114 115 #ifdef CONFIG_PPC64 116 static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx, 117 struct ocxl_ioctl_p9_wait __user *uarg) 118 { 119 struct ocxl_ioctl_p9_wait arg; 120 121 memset(&arg, 0, sizeof(arg)); 122 123 if (cpu_has_feature(CPU_FTR_P9_TIDR)) { 124 enum ocxl_context_status status; 125 126 // Locks both status & tidr 127 mutex_lock(&ctx->status_mutex); 128 if (!ctx->tidr) { 129 if (set_thread_tidr(current)) { 130 mutex_unlock(&ctx->status_mutex); 131 return -ENOENT; 132 } 133 134 ctx->tidr = current->thread.tidr; 135 } 136 137 status = ctx->status; 138 mutex_unlock(&ctx->status_mutex); 139 140 if (status == ATTACHED) { 141 int rc = ocxl_link_update_pe(ctx->afu->fn->link, 142 ctx->pasid, ctx->tidr); 143 144 if (rc) 145 return rc; 146 } 147 148 arg.thread_id = ctx->tidr; 149 } else 150 return -ENOENT; 151 152 if (copy_to_user(uarg, &arg, sizeof(arg))) 153 return -EFAULT; 154 155 return 0; 156 } 157 #endif 158 159 160 static long afu_ioctl_get_features(struct ocxl_context *ctx, 161 struct ocxl_ioctl_features __user *uarg) 162 { 163 struct ocxl_ioctl_features arg; 164 165 memset(&arg, 0, sizeof(arg)); 166 167 #ifdef CONFIG_PPC64 168 if (cpu_has_feature(CPU_FTR_P9_TIDR)) 169 arg.flags[0] |= OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT; 170 #endif 171 172 if (copy_to_user(uarg, &arg, sizeof(arg))) 173 return -EFAULT; 174 175 return 0; 176 } 177 178 #define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" : \ 179 x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" : \ 180 x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" : \ 181 x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" : \ 182 x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" : \ 183 x == OCXL_IOCTL_ENABLE_P9_WAIT ? "ENABLE_P9_WAIT" : \ 184 x == OCXL_IOCTL_GET_FEATURES ? "GET_FEATURES" : \ 185 "UNKNOWN") 186 187 static irqreturn_t irq_handler(void *private) 188 { 189 struct eventfd_ctx *ev_ctx = private; 190 191 eventfd_signal(ev_ctx, 1); 192 return IRQ_HANDLED; 193 } 194 195 static void irq_free(void *private) 196 { 197 struct eventfd_ctx *ev_ctx = private; 198 199 eventfd_ctx_put(ev_ctx); 200 } 201 202 static long afu_ioctl(struct file *file, unsigned int cmd, 203 unsigned long args) 204 { 205 struct ocxl_context *ctx = file->private_data; 206 struct ocxl_ioctl_irq_fd irq_fd; 207 struct eventfd_ctx *ev_ctx; 208 int irq_id; 209 u64 irq_offset; 210 long rc; 211 bool closed; 212 213 pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid, 214 CMD_STR(cmd)); 215 216 mutex_lock(&ctx->status_mutex); 217 closed = (ctx->status == CLOSED); 218 mutex_unlock(&ctx->status_mutex); 219 220 if (closed) 221 return -EIO; 222 223 switch (cmd) { 224 case OCXL_IOCTL_ATTACH: 225 rc = afu_ioctl_attach(ctx, 226 (struct ocxl_ioctl_attach __user *) args); 227 break; 228 229 case OCXL_IOCTL_IRQ_ALLOC: 230 rc = ocxl_afu_irq_alloc(ctx, &irq_id); 231 if (!rc) { 232 irq_offset = ocxl_irq_id_to_offset(ctx, irq_id); 233 rc = copy_to_user((u64 __user *) args, &irq_offset, 234 sizeof(irq_offset)); 235 if (rc) { 236 ocxl_afu_irq_free(ctx, irq_id); 237 return -EFAULT; 238 } 239 } 240 break; 241 242 case OCXL_IOCTL_IRQ_FREE: 243 rc = copy_from_user(&irq_offset, (u64 __user *) args, 244 sizeof(irq_offset)); 245 if (rc) 246 return -EFAULT; 247 irq_id = ocxl_irq_offset_to_id(ctx, irq_offset); 248 rc = ocxl_afu_irq_free(ctx, irq_id); 249 break; 250 251 case OCXL_IOCTL_IRQ_SET_FD: 252 rc = copy_from_user(&irq_fd, (u64 __user *) args, 253 sizeof(irq_fd)); 254 if (rc) 255 return -EFAULT; 256 if (irq_fd.reserved) 257 return -EINVAL; 258 irq_id = ocxl_irq_offset_to_id(ctx, irq_fd.irq_offset); 259 ev_ctx = eventfd_ctx_fdget(irq_fd.eventfd); 260 if (IS_ERR(ev_ctx)) 261 return PTR_ERR(ev_ctx); 262 rc = ocxl_irq_set_handler(ctx, irq_id, irq_handler, irq_free, ev_ctx); 263 break; 264 265 case OCXL_IOCTL_GET_METADATA: 266 rc = afu_ioctl_get_metadata(ctx, 267 (struct ocxl_ioctl_metadata __user *) args); 268 break; 269 270 #ifdef CONFIG_PPC64 271 case OCXL_IOCTL_ENABLE_P9_WAIT: 272 rc = afu_ioctl_enable_p9_wait(ctx, 273 (struct ocxl_ioctl_p9_wait __user *) args); 274 break; 275 #endif 276 277 case OCXL_IOCTL_GET_FEATURES: 278 rc = afu_ioctl_get_features(ctx, 279 (struct ocxl_ioctl_features __user *) args); 280 break; 281 282 default: 283 rc = -EINVAL; 284 } 285 return rc; 286 } 287 288 static long afu_compat_ioctl(struct file *file, unsigned int cmd, 289 unsigned long args) 290 { 291 return afu_ioctl(file, cmd, args); 292 } 293 294 static int afu_mmap(struct file *file, struct vm_area_struct *vma) 295 { 296 struct ocxl_context *ctx = file->private_data; 297 298 pr_debug("%s for context %d\n", __func__, ctx->pasid); 299 return ocxl_context_mmap(ctx, vma); 300 } 301 302 static bool has_xsl_error(struct ocxl_context *ctx) 303 { 304 bool ret; 305 306 mutex_lock(&ctx->xsl_error_lock); 307 ret = !!ctx->xsl_error.addr; 308 mutex_unlock(&ctx->xsl_error_lock); 309 310 return ret; 311 } 312 313 /* 314 * Are there any events pending on the AFU 315 * ctx: The AFU context 316 * Returns: true if there are events pending 317 */ 318 static bool afu_events_pending(struct ocxl_context *ctx) 319 { 320 if (has_xsl_error(ctx)) 321 return true; 322 return false; 323 } 324 325 static unsigned int afu_poll(struct file *file, struct poll_table_struct *wait) 326 { 327 struct ocxl_context *ctx = file->private_data; 328 unsigned int mask = 0; 329 bool closed; 330 331 pr_debug("%s for context %d\n", __func__, ctx->pasid); 332 333 poll_wait(file, &ctx->events_wq, wait); 334 335 mutex_lock(&ctx->status_mutex); 336 closed = (ctx->status == CLOSED); 337 mutex_unlock(&ctx->status_mutex); 338 339 if (afu_events_pending(ctx)) 340 mask = EPOLLIN | EPOLLRDNORM; 341 else if (closed) 342 mask = EPOLLERR; 343 344 return mask; 345 } 346 347 /* 348 * Populate the supplied buffer with a single XSL error 349 * ctx: The AFU context to report the error from 350 * header: the event header to populate 351 * buf: The buffer to write the body into (should be at least 352 * AFU_EVENT_BODY_XSL_ERROR_SIZE) 353 * Return: the amount of buffer that was populated 354 */ 355 static ssize_t append_xsl_error(struct ocxl_context *ctx, 356 struct ocxl_kernel_event_header *header, 357 char __user *buf) 358 { 359 struct ocxl_kernel_event_xsl_fault_error body; 360 361 memset(&body, 0, sizeof(body)); 362 363 mutex_lock(&ctx->xsl_error_lock); 364 if (!ctx->xsl_error.addr) { 365 mutex_unlock(&ctx->xsl_error_lock); 366 return 0; 367 } 368 369 body.addr = ctx->xsl_error.addr; 370 body.dsisr = ctx->xsl_error.dsisr; 371 body.count = ctx->xsl_error.count; 372 373 ctx->xsl_error.addr = 0; 374 ctx->xsl_error.dsisr = 0; 375 ctx->xsl_error.count = 0; 376 377 mutex_unlock(&ctx->xsl_error_lock); 378 379 header->type = OCXL_AFU_EVENT_XSL_FAULT_ERROR; 380 381 if (copy_to_user(buf, &body, sizeof(body))) 382 return -EFAULT; 383 384 return sizeof(body); 385 } 386 387 #define AFU_EVENT_BODY_MAX_SIZE sizeof(struct ocxl_kernel_event_xsl_fault_error) 388 389 /* 390 * Reports events on the AFU 391 * Format: 392 * Header (struct ocxl_kernel_event_header) 393 * Body (struct ocxl_kernel_event_*) 394 * Header... 395 */ 396 static ssize_t afu_read(struct file *file, char __user *buf, size_t count, 397 loff_t *off) 398 { 399 struct ocxl_context *ctx = file->private_data; 400 struct ocxl_kernel_event_header header; 401 ssize_t rc; 402 ssize_t used = 0; 403 DEFINE_WAIT(event_wait); 404 405 memset(&header, 0, sizeof(header)); 406 407 /* Require offset to be 0 */ 408 if (*off != 0) 409 return -EINVAL; 410 411 if (count < (sizeof(struct ocxl_kernel_event_header) + 412 AFU_EVENT_BODY_MAX_SIZE)) 413 return -EINVAL; 414 415 for (;;) { 416 prepare_to_wait(&ctx->events_wq, &event_wait, 417 TASK_INTERRUPTIBLE); 418 419 if (afu_events_pending(ctx)) 420 break; 421 422 if (ctx->status == CLOSED) 423 break; 424 425 if (file->f_flags & O_NONBLOCK) { 426 finish_wait(&ctx->events_wq, &event_wait); 427 return -EAGAIN; 428 } 429 430 if (signal_pending(current)) { 431 finish_wait(&ctx->events_wq, &event_wait); 432 return -ERESTARTSYS; 433 } 434 435 schedule(); 436 } 437 438 finish_wait(&ctx->events_wq, &event_wait); 439 440 if (has_xsl_error(ctx)) { 441 used = append_xsl_error(ctx, &header, buf + sizeof(header)); 442 if (used < 0) 443 return used; 444 } 445 446 if (!afu_events_pending(ctx)) 447 header.flags |= OCXL_KERNEL_EVENT_FLAG_LAST; 448 449 if (copy_to_user(buf, &header, sizeof(header))) 450 return -EFAULT; 451 452 used += sizeof(header); 453 454 rc = used; 455 return rc; 456 } 457 458 static int afu_release(struct inode *inode, struct file *file) 459 { 460 struct ocxl_context *ctx = file->private_data; 461 int rc; 462 463 pr_debug("%s for device %x\n", __func__, inode->i_rdev); 464 rc = ocxl_context_detach(ctx); 465 mutex_lock(&ctx->mapping_lock); 466 ctx->mapping = NULL; 467 mutex_unlock(&ctx->mapping_lock); 468 wake_up_all(&ctx->events_wq); 469 if (rc != -EBUSY) 470 ocxl_context_free(ctx); 471 return 0; 472 } 473 474 static const struct file_operations ocxl_afu_fops = { 475 .owner = THIS_MODULE, 476 .open = afu_open, 477 .unlocked_ioctl = afu_ioctl, 478 .compat_ioctl = afu_compat_ioctl, 479 .mmap = afu_mmap, 480 .poll = afu_poll, 481 .read = afu_read, 482 .release = afu_release, 483 }; 484 485 // Free the info struct 486 static void info_release(struct device *dev) 487 { 488 struct ocxl_file_info *info = container_of(dev, struct ocxl_file_info, dev); 489 490 free_minor(info); 491 ocxl_afu_put(info->afu); 492 kfree(info); 493 } 494 495 static int ocxl_file_make_visible(struct ocxl_file_info *info) 496 { 497 int rc; 498 499 cdev_init(&info->cdev, &ocxl_afu_fops); 500 rc = cdev_add(&info->cdev, info->dev.devt, 1); 501 if (rc) { 502 dev_err(&info->dev, "Unable to add afu char device: %d\n", rc); 503 return rc; 504 } 505 506 return 0; 507 } 508 509 static void ocxl_file_make_invisible(struct ocxl_file_info *info) 510 { 511 cdev_del(&info->cdev); 512 } 513 514 int ocxl_file_register_afu(struct ocxl_afu *afu) 515 { 516 int minor; 517 int rc; 518 struct ocxl_file_info *info; 519 struct ocxl_fn *fn = afu->fn; 520 struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent); 521 522 info = kzalloc(sizeof(*info), GFP_KERNEL); 523 if (info == NULL) 524 return -ENOMEM; 525 526 minor = allocate_minor(info); 527 if (minor < 0) { 528 kfree(info); 529 return minor; 530 } 531 532 info->dev.parent = &fn->dev; 533 info->dev.devt = MKDEV(MAJOR(ocxl_dev), minor); 534 info->dev.class = ocxl_class; 535 info->dev.release = info_release; 536 537 info->afu = afu; 538 ocxl_afu_get(afu); 539 540 rc = dev_set_name(&info->dev, "%s.%s.%hhu", 541 afu->config.name, dev_name(&pci_dev->dev), afu->config.idx); 542 if (rc) 543 goto err_put; 544 545 rc = device_register(&info->dev); 546 if (rc) 547 goto err_put; 548 549 rc = ocxl_sysfs_register_afu(info); 550 if (rc) 551 goto err_unregister; 552 553 rc = ocxl_file_make_visible(info); 554 if (rc) 555 goto err_unregister; 556 557 ocxl_afu_set_private(afu, info); 558 559 return 0; 560 561 err_unregister: 562 ocxl_sysfs_unregister_afu(info); // safe to call even if register failed 563 device_unregister(&info->dev); 564 err_put: 565 ocxl_afu_put(afu); 566 free_minor(info); 567 kfree(info); 568 return rc; 569 } 570 571 void ocxl_file_unregister_afu(struct ocxl_afu *afu) 572 { 573 struct ocxl_file_info *info = ocxl_afu_get_private(afu); 574 575 if (!info) 576 return; 577 578 ocxl_file_make_invisible(info); 579 ocxl_sysfs_unregister_afu(info); 580 device_unregister(&info->dev); 581 } 582 583 static char *ocxl_devnode(struct device *dev, umode_t *mode) 584 { 585 return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev)); 586 } 587 588 int ocxl_file_init(void) 589 { 590 int rc; 591 592 mutex_init(&minors_idr_lock); 593 idr_init(&minors_idr); 594 595 rc = alloc_chrdev_region(&ocxl_dev, 0, OCXL_NUM_MINORS, "ocxl"); 596 if (rc) { 597 pr_err("Unable to allocate ocxl major number: %d\n", rc); 598 return rc; 599 } 600 601 ocxl_class = class_create(THIS_MODULE, "ocxl"); 602 if (IS_ERR(ocxl_class)) { 603 pr_err("Unable to create ocxl class\n"); 604 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); 605 return PTR_ERR(ocxl_class); 606 } 607 608 ocxl_class->devnode = ocxl_devnode; 609 return 0; 610 } 611 612 void ocxl_file_exit(void) 613 { 614 class_destroy(ocxl_class); 615 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); 616 idr_destroy(&minors_idr); 617 } 618