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 static int afu_open(struct inode *inode, struct file *file) 100 { 101 return __afu_open(inode, file, false); 102 } 103 104 static int afu_master_open(struct inode *inode, struct file *file) 105 { 106 return __afu_open(inode, file, true); 107 } 108 109 static int afu_release(struct inode *inode, struct file *file) 110 { 111 struct cxl_context *ctx = file->private_data; 112 113 pr_devel("%s: closing cxl file descriptor. pe: %i\n", 114 __func__, ctx->pe); 115 cxl_context_detach(ctx); 116 117 mutex_lock(&ctx->mapping_lock); 118 ctx->mapping = NULL; 119 mutex_unlock(&ctx->mapping_lock); 120 121 put_device(&ctx->afu->dev); 122 123 /* 124 * At this this point all bottom halfs have finished and we should be 125 * getting no more IRQs from the hardware for this context. Once it's 126 * removed from the IDR (and RCU synchronised) it's safe to free the 127 * sstp and context. 128 */ 129 cxl_context_free(ctx); 130 131 cxl_ctx_put(); 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); 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(struct file *file, unsigned int cmd, unsigned long arg) 216 { 217 struct cxl_context *ctx = file->private_data; 218 219 if (ctx->status == CLOSED) 220 return -EIO; 221 222 pr_devel("afu_ioctl\n"); 223 switch (cmd) { 224 case CXL_IOCTL_START_WORK: 225 return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg); 226 case CXL_IOCTL_GET_PROCESS_ELEMENT: 227 return afu_ioctl_process_element(ctx, (__u32 __user *)arg); 228 } 229 return -EINVAL; 230 } 231 232 static long afu_compat_ioctl(struct file *file, unsigned int cmd, 233 unsigned long arg) 234 { 235 return afu_ioctl(file, cmd, arg); 236 } 237 238 static int afu_mmap(struct file *file, struct vm_area_struct *vm) 239 { 240 struct cxl_context *ctx = file->private_data; 241 242 /* AFU must be started before we can MMIO */ 243 if (ctx->status != STARTED) 244 return -EIO; 245 246 return cxl_context_iomap(ctx, vm); 247 } 248 249 static unsigned int afu_poll(struct file *file, struct poll_table_struct *poll) 250 { 251 struct cxl_context *ctx = file->private_data; 252 int mask = 0; 253 unsigned long flags; 254 255 256 poll_wait(file, &ctx->wq, poll); 257 258 pr_devel("afu_poll wait done pe: %i\n", ctx->pe); 259 260 spin_lock_irqsave(&ctx->lock, flags); 261 if (ctx->pending_irq || ctx->pending_fault || 262 ctx->pending_afu_err) 263 mask |= POLLIN | POLLRDNORM; 264 else if (ctx->status == CLOSED) 265 /* Only error on closed when there are no futher events pending 266 */ 267 mask |= POLLERR; 268 spin_unlock_irqrestore(&ctx->lock, flags); 269 270 pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask); 271 272 return mask; 273 } 274 275 static inline int ctx_event_pending(struct cxl_context *ctx) 276 { 277 return (ctx->pending_irq || ctx->pending_fault || 278 ctx->pending_afu_err || (ctx->status == CLOSED)); 279 } 280 281 static ssize_t afu_read(struct file *file, char __user *buf, size_t count, 282 loff_t *off) 283 { 284 struct cxl_context *ctx = file->private_data; 285 struct cxl_event event; 286 unsigned long flags; 287 int rc; 288 DEFINE_WAIT(wait); 289 290 if (count < CXL_READ_MIN_SIZE) 291 return -EINVAL; 292 293 spin_lock_irqsave(&ctx->lock, flags); 294 295 for (;;) { 296 prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE); 297 if (ctx_event_pending(ctx)) 298 break; 299 300 if (file->f_flags & O_NONBLOCK) { 301 rc = -EAGAIN; 302 goto out; 303 } 304 305 if (signal_pending(current)) { 306 rc = -ERESTARTSYS; 307 goto out; 308 } 309 310 spin_unlock_irqrestore(&ctx->lock, flags); 311 pr_devel("afu_read going to sleep...\n"); 312 schedule(); 313 pr_devel("afu_read woken up\n"); 314 spin_lock_irqsave(&ctx->lock, flags); 315 } 316 317 finish_wait(&ctx->wq, &wait); 318 319 memset(&event, 0, sizeof(event)); 320 event.header.process_element = ctx->pe; 321 event.header.size = sizeof(struct cxl_event_header); 322 if (ctx->pending_irq) { 323 pr_devel("afu_read delivering AFU interrupt\n"); 324 event.header.size += sizeof(struct cxl_event_afu_interrupt); 325 event.header.type = CXL_EVENT_AFU_INTERRUPT; 326 event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1; 327 clear_bit(event.irq.irq - 1, ctx->irq_bitmap); 328 if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count)) 329 ctx->pending_irq = false; 330 } else if (ctx->pending_fault) { 331 pr_devel("afu_read delivering data storage fault\n"); 332 event.header.size += sizeof(struct cxl_event_data_storage); 333 event.header.type = CXL_EVENT_DATA_STORAGE; 334 event.fault.addr = ctx->fault_addr; 335 event.fault.dsisr = ctx->fault_dsisr; 336 ctx->pending_fault = false; 337 } else if (ctx->pending_afu_err) { 338 pr_devel("afu_read delivering afu error\n"); 339 event.header.size += sizeof(struct cxl_event_afu_error); 340 event.header.type = CXL_EVENT_AFU_ERROR; 341 event.afu_error.error = ctx->afu_err; 342 ctx->pending_afu_err = false; 343 } else if (ctx->status == CLOSED) { 344 pr_devel("afu_read fatal error\n"); 345 spin_unlock_irqrestore(&ctx->lock, flags); 346 return -EIO; 347 } else 348 WARN(1, "afu_read must be buggy\n"); 349 350 spin_unlock_irqrestore(&ctx->lock, flags); 351 352 if (copy_to_user(buf, &event, event.header.size)) 353 return -EFAULT; 354 return event.header.size; 355 356 out: 357 finish_wait(&ctx->wq, &wait); 358 spin_unlock_irqrestore(&ctx->lock, flags); 359 return rc; 360 } 361 362 static const struct file_operations afu_fops = { 363 .owner = THIS_MODULE, 364 .open = afu_open, 365 .poll = afu_poll, 366 .read = afu_read, 367 .release = afu_release, 368 .unlocked_ioctl = afu_ioctl, 369 .compat_ioctl = afu_compat_ioctl, 370 .mmap = afu_mmap, 371 }; 372 373 static const struct file_operations afu_master_fops = { 374 .owner = THIS_MODULE, 375 .open = afu_master_open, 376 .poll = afu_poll, 377 .read = afu_read, 378 .release = afu_release, 379 .unlocked_ioctl = afu_ioctl, 380 .compat_ioctl = afu_compat_ioctl, 381 .mmap = afu_mmap, 382 }; 383 384 385 static char *cxl_devnode(struct device *dev, umode_t *mode) 386 { 387 if (CXL_DEVT_IS_CARD(dev->devt)) { 388 /* 389 * These minor numbers will eventually be used to program the 390 * PSL and AFUs once we have dynamic reprogramming support 391 */ 392 return NULL; 393 } 394 return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev)); 395 } 396 397 extern struct class *cxl_class; 398 399 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev, 400 struct device **chardev, char *postfix, char *desc, 401 const struct file_operations *fops) 402 { 403 struct device *dev; 404 int rc; 405 406 cdev_init(cdev, fops); 407 if ((rc = cdev_add(cdev, devt, 1))) { 408 dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc); 409 return rc; 410 } 411 412 dev = device_create(cxl_class, &afu->dev, devt, afu, 413 "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix); 414 if (IS_ERR(dev)) { 415 dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc); 416 rc = PTR_ERR(dev); 417 goto err; 418 } 419 420 *chardev = dev; 421 422 return 0; 423 err: 424 cdev_del(cdev); 425 return rc; 426 } 427 428 int cxl_chardev_d_afu_add(struct cxl_afu *afu) 429 { 430 return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d, 431 &afu->chardev_d, "d", "dedicated", 432 &afu_master_fops); /* Uses master fops */ 433 } 434 435 int cxl_chardev_m_afu_add(struct cxl_afu *afu) 436 { 437 return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m, 438 &afu->chardev_m, "m", "master", 439 &afu_master_fops); 440 } 441 442 int cxl_chardev_s_afu_add(struct cxl_afu *afu) 443 { 444 return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s, 445 &afu->chardev_s, "s", "shared", 446 &afu_fops); 447 } 448 449 void cxl_chardev_afu_remove(struct cxl_afu *afu) 450 { 451 if (afu->chardev_d) { 452 cdev_del(&afu->afu_cdev_d); 453 device_unregister(afu->chardev_d); 454 afu->chardev_d = NULL; 455 } 456 if (afu->chardev_m) { 457 cdev_del(&afu->afu_cdev_m); 458 device_unregister(afu->chardev_m); 459 afu->chardev_m = NULL; 460 } 461 if (afu->chardev_s) { 462 cdev_del(&afu->afu_cdev_s); 463 device_unregister(afu->chardev_s); 464 afu->chardev_s = NULL; 465 } 466 } 467 468 int cxl_register_afu(struct cxl_afu *afu) 469 { 470 afu->dev.class = cxl_class; 471 472 return device_register(&afu->dev); 473 } 474 475 int cxl_register_adapter(struct cxl *adapter) 476 { 477 adapter->dev.class = cxl_class; 478 479 /* 480 * Future: When we support dynamically reprogramming the PSL & AFU we 481 * will expose the interface to do that via a chardev: 482 * adapter->dev.devt = CXL_CARD_MKDEV(adapter); 483 */ 484 485 return device_register(&adapter->dev); 486 } 487 488 int __init cxl_file_init(void) 489 { 490 int rc; 491 492 /* 493 * If these change we really need to update API. Either change some 494 * flags or update API version number CXL_API_VERSION. 495 */ 496 BUILD_BUG_ON(CXL_API_VERSION != 1); 497 BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64); 498 BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8); 499 BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8); 500 BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32); 501 BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16); 502 503 if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) { 504 pr_err("Unable to allocate CXL major number: %i\n", rc); 505 return rc; 506 } 507 508 pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev)); 509 510 cxl_class = class_create(THIS_MODULE, "cxl"); 511 if (IS_ERR(cxl_class)) { 512 pr_err("Unable to create CXL class\n"); 513 rc = PTR_ERR(cxl_class); 514 goto err; 515 } 516 cxl_class->devnode = cxl_devnode; 517 518 return 0; 519 520 err: 521 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS); 522 return rc; 523 } 524 525 void cxl_file_exit(void) 526 { 527 unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS); 528 class_destroy(cxl_class); 529 } 530