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