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