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