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