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