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 if (rc) 261 eventfd_ctx_put(ev_ctx); 262 break; 263 264 case OCXL_IOCTL_GET_METADATA: 265 rc = afu_ioctl_get_metadata(ctx, 266 (struct ocxl_ioctl_metadata __user *) args); 267 break; 268 269 #ifdef CONFIG_PPC64 270 case OCXL_IOCTL_ENABLE_P9_WAIT: 271 rc = afu_ioctl_enable_p9_wait(ctx, 272 (struct ocxl_ioctl_p9_wait __user *) args); 273 break; 274 #endif 275 276 case OCXL_IOCTL_GET_FEATURES: 277 rc = afu_ioctl_get_features(ctx, 278 (struct ocxl_ioctl_features __user *) args); 279 break; 280 281 default: 282 rc = -EINVAL; 283 } 284 return rc; 285 } 286 287 static long afu_compat_ioctl(struct file *file, unsigned int cmd, 288 unsigned long args) 289 { 290 return afu_ioctl(file, cmd, args); 291 } 292 293 static int afu_mmap(struct file *file, struct vm_area_struct *vma) 294 { 295 struct ocxl_context *ctx = file->private_data; 296 297 pr_debug("%s for context %d\n", __func__, ctx->pasid); 298 return ocxl_context_mmap(ctx, vma); 299 } 300 301 static bool has_xsl_error(struct ocxl_context *ctx) 302 { 303 bool ret; 304 305 mutex_lock(&ctx->xsl_error_lock); 306 ret = !!ctx->xsl_error.addr; 307 mutex_unlock(&ctx->xsl_error_lock); 308 309 return ret; 310 } 311 312 /* 313 * Are there any events pending on the AFU 314 * ctx: The AFU context 315 * Returns: true if there are events pending 316 */ 317 static bool afu_events_pending(struct ocxl_context *ctx) 318 { 319 if (has_xsl_error(ctx)) 320 return true; 321 return false; 322 } 323 324 static unsigned int afu_poll(struct file *file, struct poll_table_struct *wait) 325 { 326 struct ocxl_context *ctx = file->private_data; 327 unsigned int mask = 0; 328 bool closed; 329 330 pr_debug("%s for context %d\n", __func__, ctx->pasid); 331 332 poll_wait(file, &ctx->events_wq, wait); 333 334 mutex_lock(&ctx->status_mutex); 335 closed = (ctx->status == CLOSED); 336 mutex_unlock(&ctx->status_mutex); 337 338 if (afu_events_pending(ctx)) 339 mask = EPOLLIN | EPOLLRDNORM; 340 else if (closed) 341 mask = EPOLLERR; 342 343 return mask; 344 } 345 346 /* 347 * Populate the supplied buffer with a single XSL error 348 * ctx: The AFU context to report the error from 349 * header: the event header to populate 350 * buf: The buffer to write the body into (should be at least 351 * AFU_EVENT_BODY_XSL_ERROR_SIZE) 352 * Return: the amount of buffer that was populated 353 */ 354 static ssize_t append_xsl_error(struct ocxl_context *ctx, 355 struct ocxl_kernel_event_header *header, 356 char __user *buf) 357 { 358 struct ocxl_kernel_event_xsl_fault_error body; 359 360 memset(&body, 0, sizeof(body)); 361 362 mutex_lock(&ctx->xsl_error_lock); 363 if (!ctx->xsl_error.addr) { 364 mutex_unlock(&ctx->xsl_error_lock); 365 return 0; 366 } 367 368 body.addr = ctx->xsl_error.addr; 369 body.dsisr = ctx->xsl_error.dsisr; 370 body.count = ctx->xsl_error.count; 371 372 ctx->xsl_error.addr = 0; 373 ctx->xsl_error.dsisr = 0; 374 ctx->xsl_error.count = 0; 375 376 mutex_unlock(&ctx->xsl_error_lock); 377 378 header->type = OCXL_AFU_EVENT_XSL_FAULT_ERROR; 379 380 if (copy_to_user(buf, &body, sizeof(body))) 381 return -EFAULT; 382 383 return sizeof(body); 384 } 385 386 #define AFU_EVENT_BODY_MAX_SIZE sizeof(struct ocxl_kernel_event_xsl_fault_error) 387 388 /* 389 * Reports events on the AFU 390 * Format: 391 * Header (struct ocxl_kernel_event_header) 392 * Body (struct ocxl_kernel_event_*) 393 * Header... 394 */ 395 static ssize_t afu_read(struct file *file, char __user *buf, size_t count, 396 loff_t *off) 397 { 398 struct ocxl_context *ctx = file->private_data; 399 struct ocxl_kernel_event_header header; 400 ssize_t rc; 401 ssize_t used = 0; 402 DEFINE_WAIT(event_wait); 403 404 memset(&header, 0, sizeof(header)); 405 406 /* Require offset to be 0 */ 407 if (*off != 0) 408 return -EINVAL; 409 410 if (count < (sizeof(struct ocxl_kernel_event_header) + 411 AFU_EVENT_BODY_MAX_SIZE)) 412 return -EINVAL; 413 414 for (;;) { 415 prepare_to_wait(&ctx->events_wq, &event_wait, 416 TASK_INTERRUPTIBLE); 417 418 if (afu_events_pending(ctx)) 419 break; 420 421 if (ctx->status == CLOSED) 422 break; 423 424 if (file->f_flags & O_NONBLOCK) { 425 finish_wait(&ctx->events_wq, &event_wait); 426 return -EAGAIN; 427 } 428 429 if (signal_pending(current)) { 430 finish_wait(&ctx->events_wq, &event_wait); 431 return -ERESTARTSYS; 432 } 433 434 schedule(); 435 } 436 437 finish_wait(&ctx->events_wq, &event_wait); 438 439 if (has_xsl_error(ctx)) { 440 used = append_xsl_error(ctx, &header, buf + sizeof(header)); 441 if (used < 0) 442 return used; 443 } 444 445 if (!afu_events_pending(ctx)) 446 header.flags |= OCXL_KERNEL_EVENT_FLAG_LAST; 447 448 if (copy_to_user(buf, &header, sizeof(header))) 449 return -EFAULT; 450 451 used += sizeof(header); 452 453 rc = used; 454 return rc; 455 } 456 457 static int afu_release(struct inode *inode, struct file *file) 458 { 459 struct ocxl_context *ctx = file->private_data; 460 int rc; 461 462 pr_debug("%s for device %x\n", __func__, inode->i_rdev); 463 rc = ocxl_context_detach(ctx); 464 mutex_lock(&ctx->mapping_lock); 465 ctx->mapping = NULL; 466 mutex_unlock(&ctx->mapping_lock); 467 wake_up_all(&ctx->events_wq); 468 if (rc != -EBUSY) 469 ocxl_context_free(ctx); 470 return 0; 471 } 472 473 static const struct file_operations ocxl_afu_fops = { 474 .owner = THIS_MODULE, 475 .open = afu_open, 476 .unlocked_ioctl = afu_ioctl, 477 .compat_ioctl = afu_compat_ioctl, 478 .mmap = afu_mmap, 479 .poll = afu_poll, 480 .read = afu_read, 481 .release = afu_release, 482 }; 483 484 // Free the info struct 485 static void info_release(struct device *dev) 486 { 487 struct ocxl_file_info *info = container_of(dev, struct ocxl_file_info, dev); 488 489 ocxl_afu_put(info->afu); 490 kfree(info); 491 } 492 493 static int ocxl_file_make_visible(struct ocxl_file_info *info) 494 { 495 int rc; 496 497 cdev_init(&info->cdev, &ocxl_afu_fops); 498 rc = cdev_add(&info->cdev, info->dev.devt, 1); 499 if (rc) { 500 dev_err(&info->dev, "Unable to add afu char device: %d\n", rc); 501 return rc; 502 } 503 504 return 0; 505 } 506 507 static void ocxl_file_make_invisible(struct ocxl_file_info *info) 508 { 509 cdev_del(&info->cdev); 510 } 511 512 int ocxl_file_register_afu(struct ocxl_afu *afu) 513 { 514 int minor; 515 int rc; 516 struct ocxl_file_info *info; 517 struct ocxl_fn *fn = afu->fn; 518 struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent); 519 520 info = kzalloc(sizeof(*info), GFP_KERNEL); 521 if (info == NULL) 522 return -ENOMEM; 523 524 minor = allocate_minor(info); 525 if (minor < 0) { 526 kfree(info); 527 return minor; 528 } 529 530 info->dev.parent = &fn->dev; 531 info->dev.devt = MKDEV(MAJOR(ocxl_dev), minor); 532 info->dev.class = ocxl_class; 533 info->dev.release = info_release; 534 535 info->afu = afu; 536 ocxl_afu_get(afu); 537 538 rc = dev_set_name(&info->dev, "%s.%s.%hhu", 539 afu->config.name, dev_name(&pci_dev->dev), afu->config.idx); 540 if (rc) 541 goto err_put; 542 543 rc = device_register(&info->dev); 544 if (rc) { 545 free_minor(info); 546 put_device(&info->dev); 547 return rc; 548 } 549 550 rc = ocxl_sysfs_register_afu(info); 551 if (rc) 552 goto err_unregister; 553 554 rc = ocxl_file_make_visible(info); 555 if (rc) 556 goto err_unregister; 557 558 ocxl_afu_set_private(afu, info); 559 560 return 0; 561 562 err_unregister: 563 ocxl_sysfs_unregister_afu(info); // safe to call even if register failed 564 free_minor(info); 565 device_unregister(&info->dev); 566 return rc; 567 err_put: 568 ocxl_afu_put(afu); 569 free_minor(info); 570 kfree(info); 571 return rc; 572 } 573 574 void ocxl_file_unregister_afu(struct ocxl_afu *afu) 575 { 576 struct ocxl_file_info *info = ocxl_afu_get_private(afu); 577 578 if (!info) 579 return; 580 581 ocxl_file_make_invisible(info); 582 ocxl_sysfs_unregister_afu(info); 583 free_minor(info); 584 device_unregister(&info->dev); 585 } 586 587 static char *ocxl_devnode(const struct device *dev, umode_t *mode) 588 { 589 return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev)); 590 } 591 592 int ocxl_file_init(void) 593 { 594 int rc; 595 596 idr_init(&minors_idr); 597 598 rc = alloc_chrdev_region(&ocxl_dev, 0, OCXL_NUM_MINORS, "ocxl"); 599 if (rc) { 600 pr_err("Unable to allocate ocxl major number: %d\n", rc); 601 return rc; 602 } 603 604 ocxl_class = class_create("ocxl"); 605 if (IS_ERR(ocxl_class)) { 606 pr_err("Unable to create ocxl class\n"); 607 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); 608 return PTR_ERR(ocxl_class); 609 } 610 611 ocxl_class->devnode = ocxl_devnode; 612 return 0; 613 } 614 615 void ocxl_file_exit(void) 616 { 617 class_destroy(ocxl_class); 618 unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); 619 idr_destroy(&minors_idr); 620 } 621