misc/cxl/file.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Copyright 2014 IBM Corp.
0004  */
0005
0006 #include <linux/spinlock.h>
0007 #include <linux/module.h>
0008 #include <linux/export.h>
0009 #include <linux/kernel.h>
0010 #include <linux/bitmap.h>
0011 #include <linux/sched/signal.h>
0012 #include <linux/poll.h>
0013 #include <linux/pid.h>
0014 #include <linux/fs.h>
0015 #include <linux/mm.h>
0016 #include <linux/slab.h>
0017 #include <linux/sched/mm.h>
0018 #include <linux/mmu_context.h>
0019 #include <asm/cputable.h>
0020 #include <asm/current.h>
0021 #include <asm/copro.h>
0022
0023 #include "cxl.h"
0024 #include "trace.h"
0025
0026 #define CXL_NUM_MINORS 256 /* Total to reserve */
0027
0028 #define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
0029 #define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
0030 #define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
0031 #define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))
0032 #define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
0033 #define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))
0034
0035 #define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
0036
0037 #define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
0038
0039 static dev_t cxl_dev;
0040
0041 static struct class *cxl_class;
0042
0043 static int __afu_open(struct inode *inode, struct file *file, bool master)
0044 {
0045     struct cxl *adapter;
0046     struct cxl_afu *afu;
0047     struct cxl_context *ctx;
0048     int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
0049     int slice = CXL_DEVT_AFU(inode->i_rdev);
0050     int rc = -ENODEV;
0051
0052     pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
0053
0054     if (!(adapter = get_cxl_adapter(adapter_num)))
0055         return -ENODEV;
0056
0057     if (slice > adapter->slices)
0058         goto err_put_adapter;
0059
0060     spin_lock(&adapter->afu_list_lock);
0061     if (!(afu = adapter->afu[slice])) {
0062         spin_unlock(&adapter->afu_list_lock);
0063         goto err_put_adapter;
0064     }
0065
0066     /*
0067      * taking a ref to the afu so that it doesn't go away
0068      * for rest of the function. This ref is released before
0069      * we return.
0070      */
0071     cxl_afu_get(afu);
0072     spin_unlock(&adapter->afu_list_lock);
0073
0074     if (!afu->current_mode)
0075         goto err_put_afu;
0076
0077     if (!cxl_ops->link_ok(adapter, afu)) {
0078         rc = -EIO;
0079         goto err_put_afu;
0080     }
0081
0082     if (!(ctx = cxl_context_alloc())) {
0083         rc = -ENOMEM;
0084         goto err_put_afu;
0085     }
0086
0087     rc = cxl_context_init(ctx, afu, master);
0088     if (rc)
0089         goto err_put_afu;
0090
0091     cxl_context_set_mapping(ctx, inode->i_mapping);
0092
0093     pr_devel("afu_open pe: %i\n", ctx->pe);
0094     file->private_data = ctx;
0095
0096     /* indicate success */
0097     rc = 0;
0098
0099 err_put_afu:
0100     /* release the ref taken earlier */
0101     cxl_afu_put(afu);
0102 err_put_adapter:
0103     put_device(&adapter->dev);
0104     return rc;
0105 }
0106
0107 int afu_open(struct inode *inode, struct file *file)
0108 {
0109     return __afu_open(inode, file, false);
0110 }
0111
0112 static int afu_master_open(struct inode *inode, struct file *file)
0113 {
0114     return __afu_open(inode, file, true);
0115 }
0116
0117 int afu_release(struct inode *inode, struct file *file)
0118 {
0119     struct cxl_context *ctx = file->private_data;
0120
0121     pr_devel("%s: closing cxl file descriptor. pe: %i\n",
0122          __func__, ctx->pe);
0123     cxl_context_detach(ctx);
0124
0125
0126     /*
0127      * Delete the context's mapping pointer, unless it's created by the
0128      * kernel API, in which case leave it so it can be freed by reclaim_ctx()
0129      */
0130     if (!ctx->kernelapi) {
0131         mutex_lock(&ctx->mapping_lock);
0132         ctx->mapping = NULL;
0133         mutex_unlock(&ctx->mapping_lock);
0134     }
0135
0136     /*
0137      * At this this point all bottom halfs have finished and we should be
0138      * getting no more IRQs from the hardware for this context.  Once it's
0139      * removed from the IDR (and RCU synchronised) it's safe to free the
0140      * sstp and context.
0141      */
0142     cxl_context_free(ctx);
0143
0144     return 0;
0145 }
0146
0147 static long afu_ioctl_start_work(struct cxl_context *ctx,
0148                  struct cxl_ioctl_start_work __user *uwork)
0149 {
0150     struct cxl_ioctl_start_work work;
0151     u64 amr = 0;
0152     int rc;
0153
0154     pr_devel("%s: pe: %i\n", __func__, ctx->pe);
0155
0156     /* Do this outside the status_mutex to avoid a circular dependency with
0157      * the locking in cxl_mmap_fault() */
0158     if (copy_from_user(&work, uwork, sizeof(work)))
0159         return -EFAULT;
0160
0161     mutex_lock(&ctx->status_mutex);
0162     if (ctx->status != OPENED) {
0163         rc = -EIO;
0164         goto out;
0165     }
0166
0167     /*
0168      * if any of the reserved fields are set or any of the unused
0169      * flags are set it's invalid
0170      */
0171     if (work.reserved1 || work.reserved2 || work.reserved3 ||
0172         work.reserved4 || work.reserved5 ||
0173         (work.flags & ~CXL_START_WORK_ALL)) {
0174         rc = -EINVAL;
0175         goto out;
0176     }
0177
0178     if (!(work.flags & CXL_START_WORK_NUM_IRQS))
0179         work.num_interrupts = ctx->afu->pp_irqs;
0180     else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
0181          (work.num_interrupts > ctx->afu->irqs_max)) {
0182         rc =  -EINVAL;
0183         goto out;
0184     }
0185
0186     if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
0187         goto out;
0188
0189     if (work.flags & CXL_START_WORK_AMR)
0190         amr = work.amr & mfspr(SPRN_UAMOR);
0191
0192     if (work.flags & CXL_START_WORK_TID)
0193         ctx->assign_tidr = true;
0194
0195     ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
0196
0197     /*
0198      * Increment the mapped context count for adapter. This also checks
0199      * if adapter_context_lock is taken.
0200      */
0201     rc = cxl_adapter_context_get(ctx->afu->adapter);
0202     if (rc) {
0203         afu_release_irqs(ctx, ctx);
0204         goto out;
0205     }
0206
0207     /*
0208      * We grab the PID here and not in the file open to allow for the case
0209      * where a process (master, some daemon, etc) has opened the chardev on
0210      * behalf of another process, so the AFU's mm gets bound to the process
0211      * that performs this ioctl and not the process that opened the file.
0212      * Also we grab the PID of the group leader so that if the task that
0213      * has performed the attach operation exits the mm context of the
0214      * process is still accessible.
0215      */
0216     ctx->pid = get_task_pid(current, PIDTYPE_PID);
0217
0218     /* acquire a reference to the task's mm */
0219     ctx->mm = get_task_mm(current);
0220
0221     /* ensure this mm_struct can't be freed */
0222     cxl_context_mm_count_get(ctx);
0223
0224     if (ctx->mm) {
0225         /* decrement the use count from above */
0226         mmput(ctx->mm);
0227         /* make TLBIs for this context global */
0228         mm_context_add_copro(ctx->mm);
0229     }
0230
0231     /*
0232      * Increment driver use count. Enables global TLBIs for hash
0233      * and callbacks to handle the segment table
0234      */
0235     cxl_ctx_get();
0236
0237     /*
0238      * A barrier is needed to make sure all TLBIs are global
0239      * before we attach and the context starts being used by the
0240      * adapter.
0241      *
0242      * Needed after mm_context_add_copro() for radix and
0243      * cxl_ctx_get() for hash/p8.
0244      *
0245      * The barrier should really be mb(), since it involves a
0246      * device. However, it's only useful when we have local
0247      * vs. global TLBIs, i.e SMP=y. So keep smp_mb().
0248      */
0249     smp_mb();
0250
0251     trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
0252
0253     if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
0254                             amr))) {
0255         afu_release_irqs(ctx, ctx);
0256         cxl_adapter_context_put(ctx->afu->adapter);
0257         put_pid(ctx->pid);
0258         ctx->pid = NULL;
0259         cxl_ctx_put();
0260         cxl_context_mm_count_put(ctx);
0261         if (ctx->mm)
0262             mm_context_remove_copro(ctx->mm);
0263         goto out;
0264     }
0265
0266     rc = 0;
0267     if (work.flags & CXL_START_WORK_TID) {
0268         work.tid = ctx->tidr;
0269         if (copy_to_user(uwork, &work, sizeof(work)))
0270             rc = -EFAULT;
0271     }
0272
0273     ctx->status = STARTED;
0274
0275 out:
0276     mutex_unlock(&ctx->status_mutex);
0277     return rc;
0278 }
0279
0280 static long afu_ioctl_process_element(struct cxl_context *ctx,
0281                       int __user *upe)
0282 {
0283     pr_devel("%s: pe: %i\n", __func__, ctx->pe);
0284
0285     if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
0286         return -EFAULT;
0287
0288     return 0;
0289 }
0290
0291 static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
0292                  struct cxl_afu_id __user *upafuid)
0293 {
0294     struct cxl_afu_id afuid = { 0 };
0295
0296     afuid.card_id = ctx->afu->adapter->adapter_num;
0297     afuid.afu_offset = ctx->afu->slice;
0298     afuid.afu_mode = ctx->afu->current_mode;
0299
0300     /* set the flag bit in case the afu is a slave */
0301     if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
0302         afuid.flags |= CXL_AFUID_FLAG_SLAVE;
0303
0304     if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
0305         return -EFAULT;
0306
0307     return 0;
0308 }
0309
0310 long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
0311 {
0312     struct cxl_context *ctx = file->private_data;
0313
0314     if (ctx->status == CLOSED)
0315         return -EIO;
0316
0317     if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0318         return -EIO;
0319
0320     pr_devel("afu_ioctl\n");
0321     switch (cmd) {
0322     case CXL_IOCTL_START_WORK:
0323         return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
0324     case CXL_IOCTL_GET_PROCESS_ELEMENT:
0325         return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
0326     case CXL_IOCTL_GET_AFU_ID:
0327         return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
0328                         arg);
0329     }
0330     return -EINVAL;
0331 }
0332
0333 static long afu_compat_ioctl(struct file *file, unsigned int cmd,
0334                  unsigned long arg)
0335 {
0336     return afu_ioctl(file, cmd, arg);
0337 }
0338
0339 int afu_mmap(struct file *file, struct vm_area_struct *vm)
0340 {
0341     struct cxl_context *ctx = file->private_data;
0342
0343     /* AFU must be started before we can MMIO */
0344     if (ctx->status != STARTED)
0345         return -EIO;
0346
0347     if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0348         return -EIO;
0349
0350     return cxl_context_iomap(ctx, vm);
0351 }
0352
0353 static inline bool ctx_event_pending(struct cxl_context *ctx)
0354 {
0355     if (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err)
0356         return true;
0357
0358     if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))
0359         return true;
0360
0361     return false;
0362 }
0363
0364 __poll_t afu_poll(struct file *file, struct poll_table_struct *poll)
0365 {
0366     struct cxl_context *ctx = file->private_data;
0367     __poll_t mask = 0;
0368     unsigned long flags;
0369
0370
0371     poll_wait(file, &ctx->wq, poll);
0372
0373     pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
0374
0375     spin_lock_irqsave(&ctx->lock, flags);
0376     if (ctx_event_pending(ctx))
0377         mask |= EPOLLIN | EPOLLRDNORM;
0378     else if (ctx->status == CLOSED)
0379         /* Only error on closed when there are no futher events pending
0380          */
0381         mask |= EPOLLERR;
0382     spin_unlock_irqrestore(&ctx->lock, flags);
0383
0384     pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
0385
0386     return mask;
0387 }
0388
0389 static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
0390                      char __user *buf,
0391                      struct cxl_event *event,
0392                      struct cxl_event_afu_driver_reserved *pl)
0393 {
0394     /* Check event */
0395     if (!pl) {
0396         ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
0397         return -EFAULT;
0398     }
0399
0400     /* Check event size */
0401     event->header.size += pl->data_size;
0402     if (event->header.size > CXL_READ_MIN_SIZE) {
0403         ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
0404         return -EFAULT;
0405     }
0406
0407     /* Copy event header */
0408     if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {
0409         ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
0410         return -EFAULT;
0411     }
0412
0413     /* Copy event data */
0414     buf += sizeof(struct cxl_event_header);
0415     if (copy_to_user(buf, &pl->data, pl->data_size)) {
0416         ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
0417         return -EFAULT;
0418     }
0419
0420     ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */
0421     return event->header.size;
0422 }
0423
0424 ssize_t afu_read(struct file *file, char __user *buf, size_t count,
0425             loff_t *off)
0426 {
0427     struct cxl_context *ctx = file->private_data;
0428     struct cxl_event_afu_driver_reserved *pl = NULL;
0429     struct cxl_event event;
0430     unsigned long flags;
0431     int rc;
0432     DEFINE_WAIT(wait);
0433
0434     if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0435         return -EIO;
0436
0437     if (count < CXL_READ_MIN_SIZE)
0438         return -EINVAL;
0439
0440     spin_lock_irqsave(&ctx->lock, flags);
0441
0442     for (;;) {
0443         prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
0444         if (ctx_event_pending(ctx) || (ctx->status == CLOSED))
0445             break;
0446
0447         if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
0448             rc = -EIO;
0449             goto out;
0450         }
0451
0452         if (file->f_flags & O_NONBLOCK) {
0453             rc = -EAGAIN;
0454             goto out;
0455         }
0456
0457         if (signal_pending(current)) {
0458             rc = -ERESTARTSYS;
0459             goto out;
0460         }
0461
0462         spin_unlock_irqrestore(&ctx->lock, flags);
0463         pr_devel("afu_read going to sleep...\n");
0464         schedule();
0465         pr_devel("afu_read woken up\n");
0466         spin_lock_irqsave(&ctx->lock, flags);
0467     }
0468
0469     finish_wait(&ctx->wq, &wait);
0470
0471     memset(&event, 0, sizeof(event));
0472     event.header.process_element = ctx->pe;
0473     event.header.size = sizeof(struct cxl_event_header);
0474     if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) {
0475         pr_devel("afu_read delivering AFU driver specific event\n");
0476         pl = ctx->afu_driver_ops->fetch_event(ctx);
0477         atomic_dec(&ctx->afu_driver_events);
0478         event.header.type = CXL_EVENT_AFU_DRIVER;
0479     } else if (ctx->pending_irq) {
0480         pr_devel("afu_read delivering AFU interrupt\n");
0481         event.header.size += sizeof(struct cxl_event_afu_interrupt);
0482         event.header.type = CXL_EVENT_AFU_INTERRUPT;
0483         event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
0484         clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
0485         if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
0486             ctx->pending_irq = false;
0487     } else if (ctx->pending_fault) {
0488         pr_devel("afu_read delivering data storage fault\n");
0489         event.header.size += sizeof(struct cxl_event_data_storage);
0490         event.header.type = CXL_EVENT_DATA_STORAGE;
0491         event.fault.addr = ctx->fault_addr;
0492         event.fault.dsisr = ctx->fault_dsisr;
0493         ctx->pending_fault = false;
0494     } else if (ctx->pending_afu_err) {
0495         pr_devel("afu_read delivering afu error\n");
0496         event.header.size += sizeof(struct cxl_event_afu_error);
0497         event.header.type = CXL_EVENT_AFU_ERROR;
0498         event.afu_error.error = ctx->afu_err;
0499         ctx->pending_afu_err = false;
0500     } else if (ctx->status == CLOSED) {
0501         pr_devel("afu_read fatal error\n");
0502         spin_unlock_irqrestore(&ctx->lock, flags);
0503         return -EIO;
0504     } else
0505         WARN(1, "afu_read must be buggy\n");
0506
0507     spin_unlock_irqrestore(&ctx->lock, flags);
0508
0509     if (event.header.type == CXL_EVENT_AFU_DRIVER)
0510         return afu_driver_event_copy(ctx, buf, &event, pl);
0511
0512     if (copy_to_user(buf, &event, event.header.size))
0513         return -EFAULT;
0514     return event.header.size;
0515
0516 out:
0517     finish_wait(&ctx->wq, &wait);
0518     spin_unlock_irqrestore(&ctx->lock, flags);
0519     return rc;
0520 }
0521
0522 /*
0523  * Note: if this is updated, we need to update api.c to patch the new ones in
0524  * too
0525  */
0526 const struct file_operations afu_fops = {
0527     .owner      = THIS_MODULE,
0528     .open           = afu_open,
0529     .poll       = afu_poll,
0530     .read       = afu_read,
0531     .release        = afu_release,
0532     .unlocked_ioctl = afu_ioctl,
0533     .compat_ioctl   = afu_compat_ioctl,
0534     .mmap           = afu_mmap,
0535 };
0536
0537 static const struct file_operations afu_master_fops = {
0538     .owner      = THIS_MODULE,
0539     .open           = afu_master_open,
0540     .poll       = afu_poll,
0541     .read       = afu_read,
0542     .release        = afu_release,
0543     .unlocked_ioctl = afu_ioctl,
0544     .compat_ioctl   = afu_compat_ioctl,
0545     .mmap           = afu_mmap,
0546 };
0547
0548
0549 static char *cxl_devnode(struct device *dev, umode_t *mode)
0550 {
0551     if (cpu_has_feature(CPU_FTR_HVMODE) &&
0552         CXL_DEVT_IS_CARD(dev->devt)) {
0553         /*
0554          * These minor numbers will eventually be used to program the
0555          * PSL and AFUs once we have dynamic reprogramming support
0556          */
0557         return NULL;
0558     }
0559     return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
0560 }
0561
0562 extern struct class *cxl_class;
0563
0564 static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
0565                struct device **chardev, char *postfix, char *desc,
0566                const struct file_operations *fops)
0567 {
0568     struct device *dev;
0569     int rc;
0570
0571     cdev_init(cdev, fops);
0572     rc = cdev_add(cdev, devt, 1);
0573     if (rc) {
0574         dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
0575         return rc;
0576     }
0577
0578     dev = device_create(cxl_class, &afu->dev, devt, afu,
0579             "afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
0580     if (IS_ERR(dev)) {
0581         rc = PTR_ERR(dev);
0582         dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
0583         goto err;
0584     }
0585
0586     *chardev = dev;
0587
0588     return 0;
0589 err:
0590     cdev_del(cdev);
0591     return rc;
0592 }
0593
0594 int cxl_chardev_d_afu_add(struct cxl_afu *afu)
0595 {
0596     return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
0597                    &afu->chardev_d, "d", "dedicated",
0598                    &afu_master_fops); /* Uses master fops */
0599 }
0600
0601 int cxl_chardev_m_afu_add(struct cxl_afu *afu)
0602 {
0603     return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
0604                    &afu->chardev_m, "m", "master",
0605                    &afu_master_fops);
0606 }
0607
0608 int cxl_chardev_s_afu_add(struct cxl_afu *afu)
0609 {
0610     return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
0611                    &afu->chardev_s, "s", "shared",
0612                    &afu_fops);
0613 }
0614
0615 void cxl_chardev_afu_remove(struct cxl_afu *afu)
0616 {
0617     if (afu->chardev_d) {
0618         cdev_del(&afu->afu_cdev_d);
0619         device_unregister(afu->chardev_d);
0620         afu->chardev_d = NULL;
0621     }
0622     if (afu->chardev_m) {
0623         cdev_del(&afu->afu_cdev_m);
0624         device_unregister(afu->chardev_m);
0625         afu->chardev_m = NULL;
0626     }
0627     if (afu->chardev_s) {
0628         cdev_del(&afu->afu_cdev_s);
0629         device_unregister(afu->chardev_s);
0630         afu->chardev_s = NULL;
0631     }
0632 }
0633
0634 int cxl_register_afu(struct cxl_afu *afu)
0635 {
0636     afu->dev.class = cxl_class;
0637
0638     return device_register(&afu->dev);
0639 }
0640
0641 int cxl_register_adapter(struct cxl *adapter)
0642 {
0643     adapter->dev.class = cxl_class;
0644
0645     /*
0646      * Future: When we support dynamically reprogramming the PSL & AFU we
0647      * will expose the interface to do that via a chardev:
0648      * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
0649      */
0650
0651     return device_register(&adapter->dev);
0652 }
0653
0654 dev_t cxl_get_dev(void)
0655 {
0656     return cxl_dev;
0657 }
0658
0659 int __init cxl_file_init(void)
0660 {
0661     int rc;
0662
0663     /*
0664      * If these change we really need to update API.  Either change some
0665      * flags or update API version number CXL_API_VERSION.
0666      */
0667     BUILD_BUG_ON(CXL_API_VERSION != 3);
0668     BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
0669     BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
0670     BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
0671     BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
0672     BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
0673
0674     if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
0675         pr_err("Unable to allocate CXL major number: %i\n", rc);
0676         return rc;
0677     }
0678
0679     pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
0680
0681     cxl_class = class_create(THIS_MODULE, "cxl");
0682     if (IS_ERR(cxl_class)) {
0683         pr_err("Unable to create CXL class\n");
0684         rc = PTR_ERR(cxl_class);
0685         goto err;
0686     }
0687     cxl_class->devnode = cxl_devnode;
0688
0689     return 0;
0690
0691 err:
0692     unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
0693     return rc;
0694 }
0695
0696 void cxl_file_exit(void)
0697 {
0698     unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
0699     class_destroy(cxl_class);
0700 }