1 /* 2 * Copyright 2014 IBM Corp. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 */ 9 10 #include <linux/spinlock.h> 11 #include <linux/module.h> 12 #include <linux/export.h> 13 #include <linux/kernel.h> 14 #include <linux/bitmap.h> 15 #include <linux/sched.h> 16 #include <linux/poll.h> 17 #include <linux/pid.h> 18 #include <linux/fs.h> 19 #include <linux/mm.h> 20 #include <linux/slab.h> 21 #include <asm/cputable.h> 22 #include <asm/current.h> 23 #include <asm/copro.h> 24 25 #include "cxl.h" 26 #include "trace.h" 27 28 #define CXL_NUM_MINORS 256 /* Total to reserve */ 29 #define CXL_DEV_MINORS 13 /* 1 control + 4 AFUs * 3 (dedicated/master/shared) */ 30 31 #define CXL_CARD_MINOR(adapter) (adapter->adapter_num * CXL_DEV_MINORS) 32 #define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice)) 33 #define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1) 34 #define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2) 35 #define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu)) 36 #define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu)) 37 #define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu)) 38 39 #define CXL_DEVT_ADAPTER(dev) (MINOR(dev) / CXL_DEV_MINORS) 40 #define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3) 41 42 #define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0) 43 44 static dev_t cxl_dev; 45 46 static struct class *cxl_class; 47 48 static int __afu_open(struct inode *inode, struct file *file, bool master) 49 { 50 struct cxl *adapter; 51 struct cxl_afu *afu; 52 struct cxl_context *ctx; 53 int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev); 54 int slice = CXL_DEVT_AFU(inode->i_rdev); 55 int rc = -ENODEV; 56 57 pr_devel("afu_open afu%i.%i\n", slice, adapter_num); 58 59 if (!(adapter = get_cxl_adapter(adapter_num))) 60 return -ENODEV; 61 62 if (slice > adapter->slices) 63 goto err_put_adapter; 64 65 spin_lock(&adapter->afu_list_lock); 66 if (!(afu = adapter->afu[slice])) { 67 spin_unlock(&adapter->afu_list_lock); 68 goto err_put_adapter; 69 } 70 71 /* 72 * taking a ref to the afu so that it doesn't go away 73 * for rest of the function. This ref is released before 74 * we return. 75 */ 76 cxl_afu_get(afu); 77 spin_unlock(&adapter->afu_list_lock); 78 79 if (!afu->current_mode) 80 goto err_put_afu; 81 82 if (!cxl_adapter_link_ok(adapter)) { 83 rc = -EIO; 84 goto err_put_afu; 85 } 86 87 if (!(ctx = cxl_context_alloc())) { 88 rc = -ENOMEM; 89 goto err_put_afu; 90 } 91 92 if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping))) 93 goto err_put_afu; 94 95 pr_devel("afu_open pe: %i\n", ctx->pe); 96 file->private_data = ctx; 97 cxl_ctx_get(); 98 99 /* indicate success */ 100 rc = 0; 101 102 err_put_afu: 103 /* release the ref taken earlier */ 104 cxl_afu_put(afu); 105 err_put_adapter: 106 put_device(&adapter->dev); 107 return rc; 108 } 109 110 int afu_open(struct inode *inode, struct file *file) 111 { 112 return __afu_open(inode, file, false); 113 } 114 115 static int afu_master_open(struct inode *inode, struct file *file) 116 { 117 return __afu_open(inode, file, true); 118 } 119 120 int afu_release(struct inode *inode, struct file *file) 121 { 122 struct cxl_context *ctx = file->private_data; 123 124 pr_devel("%s: closing cxl file descriptor. pe: %i\n", 125 __func__, ctx->pe); 126 cxl_context_detach(ctx); 127 128 129 /* 130 * Delete the context's mapping pointer, unless it's created by the 131 * kernel API, in which case leave it so it can be freed by reclaim_ctx() 132 */ 133 if (!ctx->kernelapi) { 134 mutex_lock(&ctx->mapping_lock); 135 ctx->mapping = NULL; 136 mutex_unlock(&ctx->mapping_lock); 137 } 138 139 /* 140 * At this this point all bottom halfs have finished and we should be 141 * getting no more IRQs from the hardware for this context. Once it's 142 * removed from the IDR (and RCU synchronised) it's safe to free the 143 * sstp and context. 144 */ 145 cxl_context_free(ctx); 146 147 return 0; 148 } 149 150 static long afu_ioctl_start_work(struct cxl_context *ctx, 151 struct cxl_ioctl_start_work __user *uwork) 152 { 153 struct cxl_ioctl_start_work work; 154 u64 amr = 0; 155 int rc; 156 157 pr_devel("%s: pe: %i\n", __func__, ctx->pe); 158 159 /* Do this outside the status_mutex to avoid a circular dependency with 160 * the locking in cxl_mmap_fault() */ 161 if (copy_from_user(&work, uwork, 162 sizeof(struct cxl_ioctl_start_work))) { 163 rc = -EFAULT; 164 goto out; 165 } 166 167 mutex_lock(&ctx->status_mutex); 168 if (ctx->status != OPENED) { 169 rc = -EIO; 170 goto out; 171 } 172 173 /* 174 * if any of the reserved fields are set or any of the unused 175 * flags are set it's invalid 176 */ 177 if (work.reserved1 || work.reserved2 || work.reserved3 || 178 work.reserved4 || work.reserved5 || work.reserved6 || 179 (work.flags & ~CXL_START_WORK_ALL)) { 180 rc = -EINVAL; 181 goto out; 182 } 183 184 if (!(work.flags & CXL_START_WORK_NUM_IRQS)) 185 work.num_interrupts = ctx->afu->pp_irqs; 186 else if ((work.num_interrupts < ctx->afu->pp_irqs) || 187 (work.num_interrupts > ctx->afu->irqs_max)) { 188 rc = -EINVAL; 189 goto out; 190 } 191 if ((rc = afu_register_irqs(ctx, work.num_interrupts))) 192 goto out; 193 194 if (work.flags & CXL_START_WORK_AMR) 195 amr = work.amr & mfspr(SPRN_UAMOR); 196 197 ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF); 198 199 /* 200 * We grab the PID here and not in the file open to allow for the case 201 * where a process (master, some daemon, etc) has opened the chardev on 202 * behalf of another process, so the AFU's mm gets bound to the process 203 * that performs this ioctl and not the process that opened the file. 204 * Also we grab the PID of the group leader so that if the task that 205 * has performed the attach operation exits the mm context of the 206 * process is still accessible. 207 */ 208 ctx->pid = get_task_pid(current, PIDTYPE_PID); 209 ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID); 210 211 trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr); 212 213 if ((rc = cxl_attach_process(ctx, false, work.work_element_descriptor, 214 amr))) { 215 afu_release_irqs(ctx, ctx); 216 goto out; 217 } 218 219 ctx->status = STARTED; 220 rc = 0; 221 out: 222 mutex_unlock(&ctx->status_mutex); 223 return rc; 224 } 225 static long afu_ioctl_process_element(struct cxl_context *ctx, 226 int __user *upe) 227 { 228 pr_devel("%s: pe: %i\n", __func__, ctx->pe); 229 230 if (copy_to_user(upe, &ctx->pe, sizeof(__u32))) 231 return -EFAULT; 232 233 return 0; 234 } 235 236 static long afu_ioctl_get_afu_id(struct cxl_context *ctx, 237 struct cxl_afu_id __user *upafuid) 238 { 239 struct cxl_afu_id afuid = { 0 }; 240 241 afuid.card_id = ctx->afu->adapter->adapter_num; 242 afuid.afu_offset = ctx->afu->slice; 243 afuid.afu_mode = ctx->afu->current_mode; 244 245 /* set the flag bit in case the afu is a slave */ 246 if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master) 247 afuid.flags |= CXL_AFUID_FLAG_SLAVE; 248 249 if (copy_to_user(upafuid, &afuid, sizeof(afuid))) 250 return -EFAULT; 251 252 return 0; 253 } 254 255 long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 256 { 257 struct cxl_context *ctx = file->private_data; 258 259 if (ctx->status == CLOSED) 260 return -EIO; 261 262 if (!cxl_adapter_link_ok(ctx->afu->adapter)) 263 return -EIO; 264 265 pr_devel("afu_ioctl\n"); 266 switch (cmd) { 267 case CXL_IOCTL_START_WORK: 268 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg); 269 case CXL_IOCTL_GET_PROCESS_ELEMENT: 270 return afu_ioctl_process_element(ctx, (__u32 __user *)arg); 271 case CXL_IOCTL_GET_AFU_ID: 272 return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *) 273 arg); 274 } 275 return -EINVAL; 276 } 277 278 static long afu_compat_ioctl(struct file *file, unsigned int cmd, 279 unsigned long arg) 280 { 281 return afu_ioctl(file, cmd, arg); 282 } 283 284 int afu_mmap(struct file *file, struct vm_area_struct *vm) 285 { 286 struct cxl_context *ctx = file->private_data; 287 288 /* AFU must be started before we can MMIO */ 289 if (ctx->status != STARTED) 290 return -EIO; 291 292 if (!cxl_adapter_link_ok(ctx->afu->adapter)) 293 return -EIO; 294 295 return cxl_context_iomap(ctx, vm); 296 } 297 298 unsigned int afu_poll(struct file *file, struct poll_table_struct *poll) 299 { 300 struct cxl_context *ctx = file->private_data; 301 int mask = 0; 302 unsigned long flags; 303 304 305 poll_wait(file, &ctx->wq, poll); 306 307 pr_devel("afu_poll wait done pe: %i\n", ctx->pe); 308 309 spin_lock_irqsave(&ctx->lock, flags); 310 if (ctx->pending_irq || ctx->pending_fault || 311 ctx->pending_afu_err) 312 mask |= POLLIN | POLLRDNORM; 313 else if (ctx->status == CLOSED) 314 /* Only error on closed when there are no futher events pending 315 */ 316 mask |= POLLERR; 317 spin_unlock_irqrestore(&ctx->lock, flags); 318 319 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask); 320 321 return mask; 322 } 323 324 static inline int ctx_event_pending(struct cxl_context *ctx) 325 { 326 return (ctx->pending_irq || ctx->pending_fault || 327 ctx->pending_afu_err || (ctx->status == CLOSED)); 328 } 329 330 ssize_t afu_read(struct file *file, char __user *buf, size_t count, 331 loff_t *off) 332 { 333 struct cxl_context *ctx = file->private_data; 334 struct cxl_event event; 335 unsigned long flags; 336 int rc; 337 DEFINE_WAIT(wait); 338 339 if (!cxl_adapter_link_ok(ctx->afu->adapter)) 340 return -EIO; 341 342 if (count < CXL_READ_MIN_SIZE) 343 return -EINVAL; 344 345 spin_lock_irqsave(&ctx->lock, flags); 346 347 for (;;) { 348 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE); 349 if (ctx_event_pending(ctx)) 350 break; 351 352 if (!cxl_adapter_link_ok(ctx->afu->adapter)) { 353 rc = -EIO; 354 goto out; 355 } 356 357 if (file->f_flags & O_NONBLOCK) { 358 rc = -EAGAIN; 359 goto out; 360 } 361 362 if (signal_pending(current)) { 363 rc = -ERESTARTSYS; 364 goto out; 365 } 366 367 spin_unlock_irqrestore(&ctx->lock, flags); 368 pr_devel("afu_read going to sleep...\n"); 369 schedule(); 370 pr_devel("afu_read woken up\n"); 371 spin_lock_irqsave(&ctx->lock, flags); 372 } 373 374 finish_wait(&ctx->wq, &wait); 375 376 memset(&event, 0, sizeof(event)); 377 event.header.process_element = ctx->pe; 378 event.header.size = sizeof(struct cxl_event_header); 379 if (ctx->pending_irq) { 380 pr_devel("afu_read delivering AFU interrupt\n"); 381 event.header.size += sizeof(struct cxl_event_afu_interrupt); 382 event.header.type = CXL_EVENT_AFU_INTERRUPT; 383 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1; 384 clear_bit(event.irq.irq - 1, ctx->irq_bitmap); 385 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count)) 386 ctx->pending_irq = false; 387 } else if (ctx->pending_fault) { 388 pr_devel("afu_read delivering data storage fault\n"); 389 event.header.size += sizeof(struct cxl_event_data_storage); 390 event.header.type = CXL_EVENT_DATA_STORAGE; 391 event.fault.addr = ctx->fault_addr; 392 event.fault.dsisr = ctx->fault_dsisr; 393 ctx->pending_fault = false; 394 } else if (ctx->pending_afu_err) { 395 pr_devel("afu_read delivering afu error\n"); 396 event.header.size += sizeof(struct cxl_event_afu_error); 397 event.header.type = CXL_EVENT_AFU_ERROR; 398 event.afu_error.error = ctx->afu_err; 399 ctx->pending_afu_err = false; 400 } else if (ctx->status == CLOSED) { 401 pr_devel("afu_read fatal error\n"); 402 spin_unlock_irqrestore(&ctx->lock, flags); 403 return -EIO; 404 } else 405 WARN(1, "afu_read must be buggy\n"); 406 407 spin_unlock_irqrestore(&ctx->lock, flags); 408 409 if (copy_to_user(buf, &event, event.header.size)) 410 return -EFAULT; 411 return event.header.size; 412 413 out: 414 finish_wait(&ctx->wq, &wait); 415 spin_unlock_irqrestore(&ctx->lock, flags); 416 return rc; 417 } 418 419 /* 420 * Note: if this is updated, we need to update api.c to patch the new ones in 421 * too 422 */ 423 const struct file_operations afu_fops = { 424 .owner = THIS_MODULE, 425 .open = afu_open, 426 .poll = afu_poll, 427 .read = afu_read, 428 .release = afu_release, 429 .unlocked_ioctl = afu_ioctl, 430 .compat_ioctl = afu_compat_ioctl, 431 .mmap = afu_mmap, 432 }; 433 434 static const struct file_operations afu_master_fops = { 435 .owner = THIS_MODULE, 436 .open = afu_master_open, 437 .poll = afu_poll, 438 .read = afu_read, 439 .release = afu_release, 440 .unlocked_ioctl = afu_ioctl, 441 .compat_ioctl = afu_compat_ioctl, 442 .mmap = afu_mmap, 443 }; 444 445 446 static char *cxl_devnode(struct device *dev, umode_t *mode) 447 { 448 if (CXL_DEVT_IS_CARD(dev->devt)) { 449 /* 450 * These minor numbers will eventually be used to program the 451 * PSL and AFUs once we have dynamic reprogramming support 452 */ 453 return NULL; 454 } 455 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev)); 456 } 457 458 extern struct class *cxl_class; 459 460 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev, 461 struct device **chardev, char *postfix, char *desc, 462 const struct file_operations *fops) 463 { 464 struct device *dev; 465 int rc; 466 467 cdev_init(cdev, fops); 468 if ((rc = cdev_add(cdev, devt, 1))) { 469 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc); 470 return rc; 471 } 472 473 dev = device_create(cxl_class, &afu->dev, devt, afu, 474 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix); 475 if (IS_ERR(dev)) { 476 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc); 477 rc = PTR_ERR(dev); 478 goto err; 479 } 480 481 *chardev = dev; 482 483 return 0; 484 err: 485 cdev_del(cdev); 486 return rc; 487 } 488 489 int cxl_chardev_d_afu_add(struct cxl_afu *afu) 490 { 491 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d, 492 &afu->chardev_d, "d", "dedicated", 493 &afu_master_fops); /* Uses master fops */ 494 } 495 496 int cxl_chardev_m_afu_add(struct cxl_afu *afu) 497 { 498 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m, 499 &afu->chardev_m, "m", "master", 500 &afu_master_fops); 501 } 502 503 int cxl_chardev_s_afu_add(struct cxl_afu *afu) 504 { 505 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s, 506 &afu->chardev_s, "s", "shared", 507 &afu_fops); 508 } 509 510 void cxl_chardev_afu_remove(struct cxl_afu *afu) 511 { 512 if (afu->chardev_d) { 513 cdev_del(&afu->afu_cdev_d); 514 device_unregister(afu->chardev_d); 515 afu->chardev_d = NULL; 516 } 517 if (afu->chardev_m) { 518 cdev_del(&afu->afu_cdev_m); 519 device_unregister(afu->chardev_m); 520 afu->chardev_m = NULL; 521 } 522 if (afu->chardev_s) { 523 cdev_del(&afu->afu_cdev_s); 524 device_unregister(afu->chardev_s); 525 afu->chardev_s = NULL; 526 } 527 } 528 529 int cxl_register_afu(struct cxl_afu *afu) 530 { 531 afu->dev.class = cxl_class; 532 533 return device_register(&afu->dev); 534 } 535 536 int cxl_register_adapter(struct cxl *adapter) 537 { 538 adapter->dev.class = cxl_class; 539 540 /* 541 * Future: When we support dynamically reprogramming the PSL & AFU we 542 * will expose the interface to do that via a chardev: 543 * adapter->dev.devt = CXL_CARD_MKDEV(adapter); 544 */ 545 546 return device_register(&adapter->dev); 547 } 548 549 int __init cxl_file_init(void) 550 { 551 int rc; 552 553 /* 554 * If these change we really need to update API. Either change some 555 * flags or update API version number CXL_API_VERSION. 556 */ 557 BUILD_BUG_ON(CXL_API_VERSION != 2); 558 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64); 559 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8); 560 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8); 561 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32); 562 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16); 563 564 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) { 565 pr_err("Unable to allocate CXL major number: %i\n", rc); 566 return rc; 567 } 568 569 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev)); 570 571 cxl_class = class_create(THIS_MODULE, "cxl"); 572 if (IS_ERR(cxl_class)) { 573 pr_err("Unable to create CXL class\n"); 574 rc = PTR_ERR(cxl_class); 575 goto err; 576 } 577 cxl_class->devnode = cxl_devnode; 578 579 return 0; 580 581 err: 582 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS); 583 return rc; 584 } 585 586 void cxl_file_exit(void) 587 { 588 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS); 589 class_destroy(cxl_class); 590 } 591