[mirror_ubuntu-artful-kernel.git] / drivers / misc / cxl / file.c

/*
 * Copyright 2014 IBM Corp.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/bitmap.h>
#include <linux/sched/signal.h>
#include <linux/poll.h>
#include <linux/pid.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/sched/mm.h>
#include <asm/cputable.h>
#include <asm/current.h>
#include <asm/copro.h>

#include "cxl.h"
#include "trace.h"

#define CXL_NUM_MINORS 256 /* Total to reserve */

#define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
#define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
#define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
#define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))
#define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
#define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))

#define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)

#define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)

static dev_t cxl_dev;

static struct class *cxl_class;

static int __afu_open(struct inode *inode, struct file *file, bool master)
{
	struct cxl *adapter;
	struct cxl_afu *afu;
	struct cxl_context *ctx;
	int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
	int slice = CXL_DEVT_AFU(inode->i_rdev);
	int rc = -ENODEV;

	pr_devel("afu_open afu%i.%i\n", slice, adapter_num);

	if (!(adapter = get_cxl_adapter(adapter_num)))
		return -ENODEV;

	if (slice > adapter->slices)
		goto err_put_adapter;

	spin_lock(&adapter->afu_list_lock);
	if (!(afu = adapter->afu[slice])) {
		spin_unlock(&adapter->afu_list_lock);
		goto err_put_adapter;
	}

	/*
	 * taking a ref to the afu so that it doesn't go away
	 * for rest of the function. This ref is released before
	 * we return.
	 */
	cxl_afu_get(afu);
	spin_unlock(&adapter->afu_list_lock);

	if (!afu->current_mode)
		goto err_put_afu;

	if (!cxl_ops->link_ok(adapter, afu)) {
		rc = -EIO;
		goto err_put_afu;
	}

	if (!(ctx = cxl_context_alloc())) {
		rc = -ENOMEM;
		goto err_put_afu;
	}

	rc = cxl_context_init(ctx, afu, master);
	if (rc)
		goto err_put_afu;

	cxl_context_set_mapping(ctx, inode->i_mapping);

	pr_devel("afu_open pe: %i\n", ctx->pe);
	file->private_data = ctx;
	cxl_ctx_get();

	/* indicate success */
	rc = 0;

err_put_afu:
	/* release the ref taken earlier */
	cxl_afu_put(afu);
err_put_adapter:
	put_device(&adapter->dev);
	return rc;
}

int afu_open(struct inode *inode, struct file *file)
{
	return __afu_open(inode, file, false);
}

static int afu_master_open(struct inode *inode, struct file *file)
{
	return __afu_open(inode, file, true);
}

int afu_release(struct inode *inode, struct file *file)
{
	struct cxl_context *ctx = file->private_data;

	pr_devel("%s: closing cxl file descriptor. pe: %i\n",
		 __func__, ctx->pe);
	cxl_context_detach(ctx);


	/*
	 * Delete the context's mapping pointer, unless it's created by the
	 * kernel API, in which case leave it so it can be freed by reclaim_ctx()
	 */
	if (!ctx->kernelapi) {
		mutex_lock(&ctx->mapping_lock);
		ctx->mapping = NULL;
		mutex_unlock(&ctx->mapping_lock);
	}

	/*
	 * At this this point all bottom halfs have finished and we should be
	 * getting no more IRQs from the hardware for this context.  Once it's
	 * removed from the IDR (and RCU synchronised) it's safe to free the
	 * sstp and context.
	 */
	cxl_context_free(ctx);

	return 0;
}

static long afu_ioctl_start_work(struct cxl_context *ctx,
				 struct cxl_ioctl_start_work __user *uwork)
{
	struct cxl_ioctl_start_work work;
	u64 amr = 0;
	int rc;

	pr_devel("%s: pe: %i\n", __func__, ctx->pe);

	/* Do this outside the status_mutex to avoid a circular dependency with
	 * the locking in cxl_mmap_fault() */
	if (copy_from_user(&work, uwork, sizeof(work)))
		return -EFAULT;

	mutex_lock(&ctx->status_mutex);
	if (ctx->status != OPENED) {
		rc = -EIO;
		goto out;
	}

	/*
	 * if any of the reserved fields are set or any of the unused
	 * flags are set it's invalid
	 */
	if (work.reserved1 || work.reserved2 || work.reserved3 ||
	    work.reserved4 || work.reserved5 || work.reserved6 ||
	    (work.flags & ~CXL_START_WORK_ALL)) {
		rc = -EINVAL;
		goto out;
	}

	if (!(work.flags & CXL_START_WORK_NUM_IRQS))
		work.num_interrupts = ctx->afu->pp_irqs;
	else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
		 (work.num_interrupts > ctx->afu->irqs_max)) {
		rc =  -EINVAL;
		goto out;
	}
	if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
		goto out;

	if (work.flags & CXL_START_WORK_AMR)
		amr = work.amr & mfspr(SPRN_UAMOR);

	ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);

	/*
	 * Increment the mapped context count for adapter. This also checks
	 * if adapter_context_lock is taken.
	 */
	rc = cxl_adapter_context_get(ctx->afu->adapter);
	if (rc) {
		afu_release_irqs(ctx, ctx);
		goto out;
	}

	/*
	 * We grab the PID here and not in the file open to allow for the case
	 * where a process (master, some daemon, etc) has opened the chardev on
	 * behalf of another process, so the AFU's mm gets bound to the process
	 * that performs this ioctl and not the process that opened the file.
	 * Also we grab the PID of the group leader so that if the task that
	 * has performed the attach operation exits the mm context of the
	 * process is still accessible.
	 */
	ctx->pid = get_task_pid(current, PIDTYPE_PID);

	/* acquire a reference to the task's mm */
	ctx->mm = get_task_mm(current);

	/* ensure this mm_struct can't be freed */
	cxl_context_mm_count_get(ctx);

	/* decrement the use count */
	if (ctx->mm)
		mmput(ctx->mm);

	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);

	if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
							amr))) {
		afu_release_irqs(ctx, ctx);
		cxl_adapter_context_put(ctx->afu->adapter);
		put_pid(ctx->pid);
		ctx->pid = NULL;
		cxl_context_mm_count_put(ctx);
		goto out;
	}

	ctx->status = STARTED;
	rc = 0;
out:
	mutex_unlock(&ctx->status_mutex);
	return rc;
}

static long afu_ioctl_process_element(struct cxl_context *ctx,
				      int __user *upe)
{
	pr_devel("%s: pe: %i\n", __func__, ctx->pe);

	if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
		return -EFAULT;

	return 0;
}

static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
				 struct cxl_afu_id __user *upafuid)
{
	struct cxl_afu_id afuid = { 0 };

	afuid.card_id = ctx->afu->adapter->adapter_num;
	afuid.afu_offset = ctx->afu->slice;
	afuid.afu_mode = ctx->afu->current_mode;

	/* set the flag bit in case the afu is a slave */
	if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
		afuid.flags |= CXL_AFUID_FLAG_SLAVE;

	if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
		return -EFAULT;

	return 0;
}

long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct cxl_context *ctx = file->private_data;

	if (ctx->status == CLOSED)
		return -EIO;

	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
		return -EIO;

	pr_devel("afu_ioctl\n");
	switch (cmd) {
	case CXL_IOCTL_START_WORK:
		return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
	case CXL_IOCTL_GET_PROCESS_ELEMENT:
		return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
	case CXL_IOCTL_GET_AFU_ID:
		return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
					    arg);
	}
	return -EINVAL;
}

static long afu_compat_ioctl(struct file *file, unsigned int cmd,
			     unsigned long arg)
{
	return afu_ioctl(file, cmd, arg);
}

int afu_mmap(struct file *file, struct vm_area_struct *vm)
{
	struct cxl_context *ctx = file->private_data;

	/* AFU must be started before we can MMIO */
	if (ctx->status != STARTED)
		return -EIO;

	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
		return -EIO;

	return cxl_context_iomap(ctx, vm);
}

static inline bool ctx_event_pending(struct cxl_context *ctx)
{
	if (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err)
		return true;

	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))
		return true;

	return false;
}

unsigned int afu_poll(struct file *file, struct poll_table_struct *poll)
{
	struct cxl_context *ctx = file->private_data;
	int mask = 0;
	unsigned long flags;


	poll_wait(file, &ctx->wq, poll);

	pr_devel("afu_poll wait done pe: %i\n", ctx->pe);

	spin_lock_irqsave(&ctx->lock, flags);
	if (ctx_event_pending(ctx))
		mask |= POLLIN | POLLRDNORM;
	else if (ctx->status == CLOSED)
		/* Only error on closed when there are no futher events pending
		 */
		mask |= POLLERR;
	spin_unlock_irqrestore(&ctx->lock, flags);

	pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);

	return mask;
}

static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
				     char __user *buf,
				     struct cxl_event *event,
				     struct cxl_event_afu_driver_reserved *pl)
{
	/* Check event */
	if (!pl) {
		ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
		return -EFAULT;
	}

	/* Check event size */
	event->header.size += pl->data_size;
	if (event->header.size > CXL_READ_MIN_SIZE) {
		ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
		return -EFAULT;
	}

	/* Copy event header */
	if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {
		ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
		return -EFAULT;
	}

	/* Copy event data */
	buf += sizeof(struct cxl_event_header);
	if (copy_to_user(buf, &pl->data, pl->data_size)) {
		ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
		return -EFAULT;
	}

	ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */
	return event->header.size;
}

ssize_t afu_read(struct file *file, char __user *buf, size_t count,
			loff_t *off)
{
	struct cxl_context *ctx = file->private_data;
	struct cxl_event_afu_driver_reserved *pl = NULL;
	struct cxl_event event;
	unsigned long flags;
	int rc;
	DEFINE_WAIT(wait);

	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
		return -EIO;

	if (count < CXL_READ_MIN_SIZE)
		return -EINVAL;

	spin_lock_irqsave(&ctx->lock, flags);

	for (;;) {
		prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
		if (ctx_event_pending(ctx) || (ctx->status == CLOSED))
			break;

		if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
			rc = -EIO;
			goto out;
		}

		if (file->f_flags & O_NONBLOCK) {
			rc = -EAGAIN;
			goto out;
		}

		if (signal_pending(current)) {
			rc = -ERESTARTSYS;
			goto out;
		}

		spin_unlock_irqrestore(&ctx->lock, flags);
		pr_devel("afu_read going to sleep...\n");
		schedule();
		pr_devel("afu_read woken up\n");
		spin_lock_irqsave(&ctx->lock, flags);
	}

	finish_wait(&ctx->wq, &wait);

	memset(&event, 0, sizeof(event));
	event.header.process_element = ctx->pe;
	event.header.size = sizeof(struct cxl_event_header);
	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) {
		pr_devel("afu_read delivering AFU driver specific event\n");
		pl = ctx->afu_driver_ops->fetch_event(ctx);
		atomic_dec(&ctx->afu_driver_events);
		event.header.type = CXL_EVENT_AFU_DRIVER;
	} else if (ctx->pending_irq) {
		pr_devel("afu_read delivering AFU interrupt\n");
		event.header.size += sizeof(struct cxl_event_afu_interrupt);
		event.header.type = CXL_EVENT_AFU_INTERRUPT;
		event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
		clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
		if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
			ctx->pending_irq = false;
	} else if (ctx->pending_fault) {
		pr_devel("afu_read delivering data storage fault\n");
		event.header.size += sizeof(struct cxl_event_data_storage);
		event.header.type = CXL_EVENT_DATA_STORAGE;
		event.fault.addr = ctx->fault_addr;
		event.fault.dsisr = ctx->fault_dsisr;
		ctx->pending_fault = false;
	} else if (ctx->pending_afu_err) {
		pr_devel("afu_read delivering afu error\n");
		event.header.size += sizeof(struct cxl_event_afu_error);
		event.header.type = CXL_EVENT_AFU_ERROR;
		event.afu_error.error = ctx->afu_err;
		ctx->pending_afu_err = false;
	} else if (ctx->status == CLOSED) {
		pr_devel("afu_read fatal error\n");
		spin_unlock_irqrestore(&ctx->lock, flags);
		return -EIO;
	} else
		WARN(1, "afu_read must be buggy\n");

	spin_unlock_irqrestore(&ctx->lock, flags);

	if (event.header.type == CXL_EVENT_AFU_DRIVER)
		return afu_driver_event_copy(ctx, buf, &event, pl);

	if (copy_to_user(buf, &event, event.header.size))
		return -EFAULT;
	return event.header.size;

out:
	finish_wait(&ctx->wq, &wait);
	spin_unlock_irqrestore(&ctx->lock, flags);
	return rc;
}

/* 
 * Note: if this is updated, we need to update api.c to patch the new ones in
 * too
 */
const struct file_operations afu_fops = {
	.owner		= THIS_MODULE,
	.open           = afu_open,
	.poll		= afu_poll,
	.read		= afu_read,
	.release        = afu_release,
	.unlocked_ioctl = afu_ioctl,
	.compat_ioctl   = afu_compat_ioctl,
	.mmap           = afu_mmap,
};

static const struct file_operations afu_master_fops = {
	.owner		= THIS_MODULE,
	.open           = afu_master_open,
	.poll		= afu_poll,
	.read		= afu_read,
	.release        = afu_release,
	.unlocked_ioctl = afu_ioctl,
	.compat_ioctl   = afu_compat_ioctl,
	.mmap           = afu_mmap,
};


static char *cxl_devnode(struct device *dev, umode_t *mode)
{
	if (cpu_has_feature(CPU_FTR_HVMODE) &&
	    CXL_DEVT_IS_CARD(dev->devt)) {
		/*
		 * These minor numbers will eventually be used to program the
		 * PSL and AFUs once we have dynamic reprogramming support
		 */
		return NULL;
	}
	return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
}

extern struct class *cxl_class;

static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
			   struct device **chardev, char *postfix, char *desc,
			   const struct file_operations *fops)
{
	struct device *dev;
	int rc;

	cdev_init(cdev, fops);
	if ((rc = cdev_add(cdev, devt, 1))) {
		dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
		return rc;
	}

	dev = device_create(cxl_class, &afu->dev, devt, afu,
			"afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
	if (IS_ERR(dev)) {
		dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
		rc = PTR_ERR(dev);
		goto err;
	}

	*chardev = dev;

	return 0;
err:
	cdev_del(cdev);
	return rc;
}

int cxl_chardev_d_afu_add(struct cxl_afu *afu)
{
	return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
			       &afu->chardev_d, "d", "dedicated",
			       &afu_master_fops); /* Uses master fops */
}

int cxl_chardev_m_afu_add(struct cxl_afu *afu)
{
	return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
			       &afu->chardev_m, "m", "master",
			       &afu_master_fops);
}

int cxl_chardev_s_afu_add(struct cxl_afu *afu)
{
	return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
			       &afu->chardev_s, "s", "shared",
			       &afu_fops);
}

void cxl_chardev_afu_remove(struct cxl_afu *afu)
{
	if (afu->chardev_d) {
		cdev_del(&afu->afu_cdev_d);
		device_unregister(afu->chardev_d);
		afu->chardev_d = NULL;
	}
	if (afu->chardev_m) {
		cdev_del(&afu->afu_cdev_m);
		device_unregister(afu->chardev_m);
		afu->chardev_m = NULL;
	}
	if (afu->chardev_s) {
		cdev_del(&afu->afu_cdev_s);
		device_unregister(afu->chardev_s);
		afu->chardev_s = NULL;
	}
}

int cxl_register_afu(struct cxl_afu *afu)
{
	afu->dev.class = cxl_class;

	return device_register(&afu->dev);
}

int cxl_register_adapter(struct cxl *adapter)
{
	adapter->dev.class = cxl_class;

	/*
	 * Future: When we support dynamically reprogramming the PSL & AFU we
	 * will expose the interface to do that via a chardev:
	 * adapter->dev.devt = CXL_CARD_MKDEV(adapter);
	 */

	return device_register(&adapter->dev);
}

dev_t cxl_get_dev(void)
{
	return cxl_dev;
}

int __init cxl_file_init(void)
{
	int rc;

	/*
	 * If these change we really need to update API.  Either change some
	 * flags or update API version number CXL_API_VERSION.
	 */
	BUILD_BUG_ON(CXL_API_VERSION != 3);
	BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
	BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
	BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
	BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
	BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);

	if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
		pr_err("Unable to allocate CXL major number: %i\n", rc);
		return rc;
	}

	pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));

	cxl_class = class_create(THIS_MODULE, "cxl");
	if (IS_ERR(cxl_class)) {
		pr_err("Unable to create CXL class\n");
		rc = PTR_ERR(cxl_class);
		goto err;
	}
	cxl_class->devnode = cxl_devnode;

	return 0;

err:
	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
	return rc;
}

void cxl_file_exit(void)
{
	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
	class_destroy(cxl_class);
}
Commit	Line	Data
f204e0b8 IM	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>
174cd4b1	15	#include <linux/sched/signal.h>
f204e0b8 IM	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>
6dd2d234	21	#include <linux/sched/mm.h>
f204e0b8 IM	22	#include <asm/cputable.h>
	23	#include <asm/current.h>
	24	#include <asm/copro.h>
	25
	26	#include "cxl.h"
9bcf28cd	27	#include "trace.h"
f204e0b8 IM	28
f204e0b8 IM	29	#define CXL_NUM_MINORS 256 /* Total to reserve */
f204e0b8	30
f204e0b8 IM	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
f204e0b8 IM	38	#define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
	39
	40	#define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
	41
	42	static dev_t cxl_dev;
	43
	44	static struct class *cxl_class;
	45
	46	static int __afu_open(struct inode inode, struct file file, bool master)
	47	{
	48	struct cxl *adapter;
	49	struct cxl_afu *afu;
	50	struct cxl_context *ctx;
	51	int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
	52	int slice = CXL_DEVT_AFU(inode->i_rdev);
	53	int rc = -ENODEV;
	54
	55	pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
	56
	57	if (!(adapter = get_cxl_adapter(adapter_num)))
	58	return -ENODEV;
	59
	60	if (slice > adapter->slices)
	61	goto err_put_adapter;
	62
	63	spin_lock(&adapter->afu_list_lock);
	64	if (!(afu = adapter->afu[slice])) {
	65	spin_unlock(&adapter->afu_list_lock);
	66	goto err_put_adapter;
	67	}
1b5df59e VJ	68
	69	/*
	70	* taking a ref to the afu so that it doesn't go away
	71	* for rest of the function. This ref is released before
	72	* we return.
	73	*/
	74	cxl_afu_get(afu);
f204e0b8 IM	75	spin_unlock(&adapter->afu_list_lock);
	76
	77	if (!afu->current_mode)
	78	goto err_put_afu;
	79
0d400f77	80	if (!cxl_ops->link_ok(adapter, afu)) {
0b3f9c75 DA	81	rc = -EIO;
	82	goto err_put_afu;
	83	}
	84
f204e0b8 IM	85	if (!(ctx = cxl_context_alloc())) {
	86	rc = -ENOMEM;
	87	goto err_put_afu;
	88	}
	89
bdecf76e FB	90	rc = cxl_context_init(ctx, afu, master);
bdecf76e FB	91	if (rc)
f204e0b8 IM	92	goto err_put_afu;
f204e0b8 IM	93
bdecf76e FB	94	cxl_context_set_mapping(ctx, inode->i_mapping);
bdecf76e FB	95
f204e0b8 IM	96	pr_devel("afu_open pe: %i\n", ctx->pe);
	97	file->private_data = ctx;
	98	cxl_ctx_get();
	99
1b5df59e VJ	100	/* indicate success */
1b5df59e VJ	101	rc = 0;
f204e0b8 IM	102
f204e0b8 IM	103	err_put_afu:
1b5df59e VJ	104	/* release the ref taken earlier */
1b5df59e VJ	105	cxl_afu_put(afu);
f204e0b8 IM	106	err_put_adapter:
	107	put_device(&adapter->dev);
	108	return rc;
	109	}
0520336a MN	110
0520336a MN	111	int afu_open(struct inode inode, struct file file)
f204e0b8 IM	112	{
	113	return __afu_open(inode, file, false);
	114	}
	115
	116	static int afu_master_open(struct inode inode, struct file file)
	117	{
	118	return __afu_open(inode, file, true);
	119	}
	120
0520336a	121	int afu_release(struct inode inode, struct file file)
f204e0b8 IM	122	{
	123	struct cxl_context *ctx = file->private_data;
	124
	125	pr_devel("%s: closing cxl file descriptor. pe: %i\n",
	126	__func__, ctx->pe);
	127	cxl_context_detach(ctx);
	128
5f81b95f AD	129
	130	/*
	131	* Delete the context's mapping pointer, unless it's created by the
	132	* kernel API, in which case leave it so it can be freed by reclaim_ctx()
	133	*/
	134	if (!ctx->kernelapi) {
	135	mutex_lock(&ctx->mapping_lock);
	136	ctx->mapping = NULL;
	137	mutex_unlock(&ctx->mapping_lock);
	138	}
b123429e	139
f204e0b8 IM	140	/*
	141	* At this this point all bottom halfs have finished and we should be
	142	* getting no more IRQs from the hardware for this context. Once it's
	143	* removed from the IDR (and RCU synchronised) it's safe to free the
	144	* sstp and context.
	145	*/
	146	cxl_context_free(ctx);
	147
f204e0b8 IM	148	return 0;
	149	}
	150
	151	static long afu_ioctl_start_work(struct cxl_context *ctx,
	152	struct cxl_ioctl_start_work __user *uwork)
	153	{
	154	struct cxl_ioctl_start_work work;
	155	u64 amr = 0;
	156	int rc;
	157
	158	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
	159
0712dc7e IM	160	/* Do this outside the status_mutex to avoid a circular dependency with
0712dc7e IM	161	* the locking in cxl_mmap_fault() */
cec422c1 FB	162	if (copy_from_user(&work, uwork, sizeof(work)))
cec422c1 FB	163	return -EFAULT;
f204e0b8	164
0712dc7e IM	165	mutex_lock(&ctx->status_mutex);
	166	if (ctx->status != OPENED) {
	167	rc = -EIO;
	168	goto out;
	169	}
	170
f204e0b8 IM	171	/*
	172	* if any of the reserved fields are set or any of the unused
	173	* flags are set it's invalid
	174	*/
	175	if (work.reserved1 \|\| work.reserved2 \|\| work.reserved3 \|\|
	176	work.reserved4 \|\| work.reserved5 \|\| work.reserved6 \|\|
	177	(work.flags & ~CXL_START_WORK_ALL)) {
	178	rc = -EINVAL;
	179	goto out;
	180	}
	181
	182	if (!(work.flags & CXL_START_WORK_NUM_IRQS))
	183	work.num_interrupts = ctx->afu->pp_irqs;
	184	else if ((work.num_interrupts < ctx->afu->pp_irqs) \|\|
	185	(work.num_interrupts > ctx->afu->irqs_max)) {
	186	rc = -EINVAL;
	187	goto out;
	188	}
	189	if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
	190	goto out;
	191
	192	if (work.flags & CXL_START_WORK_AMR)
	193	amr = work.amr & mfspr(SPRN_UAMOR);
	194
d9232a3d IM	195	ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
d9232a3d IM	196
a05b82d5 VJ	197	/*
	198	* Increment the mapped context count for adapter. This also checks
	199	* if adapter_context_lock is taken.
	200	*/
	201	rc = cxl_adapter_context_get(ctx->afu->adapter);
	202	if (rc) {
	203	afu_release_irqs(ctx, ctx);
	204	goto out;
	205	}
	206
f204e0b8 IM	207	/*
	208	* We grab the PID here and not in the file open to allow for the case
	209	* where a process (master, some daemon, etc) has opened the chardev on
	210	* behalf of another process, so the AFU's mm gets bound to the process
	211	* that performs this ioctl and not the process that opened the file.
7b8ad495 VJ	212	* Also we grab the PID of the group leader so that if the task that
	213	* has performed the attach operation exits the mm context of the
	214	* process is still accessible.
f204e0b8	215	*/
7b8ad495	216	ctx->pid = get_task_pid(current, PIDTYPE_PID);
f204e0b8	217
6dd2d234 CL	218	/* acquire a reference to the task's mm */
	219	ctx->mm = get_task_mm(current);
	220
	221	/* ensure this mm_struct can't be freed */
	222	cxl_context_mm_count_get(ctx);
	223
	224	/* decrement the use count */
	225	if (ctx->mm)
	226	mmput(ctx->mm);
70b565bb	227
9bcf28cd IM	228	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
9bcf28cd IM	229
5be587b1 FB	230	if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
5be587b1 FB	231	amr))) {
6428832a	232	afu_release_irqs(ctx, ctx);
70b565bb	233	cxl_adapter_context_put(ctx->afu->adapter);
a05b82d5	234	put_pid(ctx->pid);
6dd2d234 CL	235	ctx->pid = NULL;
6dd2d234 CL	236	cxl_context_mm_count_put(ctx);
f204e0b8	237	goto out;
456295e2	238	}
f204e0b8 IM	239
	240	ctx->status = STARTED;
	241	rc = 0;
	242	out:
	243	mutex_unlock(&ctx->status_mutex);
	244	return rc;
	245	}
5be587b1	246
f204e0b8 IM	247	static long afu_ioctl_process_element(struct cxl_context *ctx,
	248	int __user *upe)
	249	{
	250	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
	251
14baf4d9	252	if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
f204e0b8 IM	253	return -EFAULT;
	254
	255	return 0;
	256	}
	257
27d4dc71 VJ	258	static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
	259	struct cxl_afu_id __user *upafuid)
	260	{
	261	struct cxl_afu_id afuid = { 0 };
	262
	263	afuid.card_id = ctx->afu->adapter->adapter_num;
	264	afuid.afu_offset = ctx->afu->slice;
	265	afuid.afu_mode = ctx->afu->current_mode;
	266
	267	/* set the flag bit in case the afu is a slave */
	268	if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
	269	afuid.flags \|= CXL_AFUID_FLAG_SLAVE;
	270
	271	if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
	272	return -EFAULT;
	273
	274	return 0;
	275	}
	276
0520336a	277	long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
f204e0b8 IM	278	{
	279	struct cxl_context *ctx = file->private_data;
	280
	281	if (ctx->status == CLOSED)
	282	return -EIO;
	283
0d400f77	284	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	285	return -EIO;
0b3f9c75 DA	286
f204e0b8 IM	287	pr_devel("afu_ioctl\n");
	288	switch (cmd) {
	289	case CXL_IOCTL_START_WORK:
	290	return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
	291	case CXL_IOCTL_GET_PROCESS_ELEMENT:
	292	return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
27d4dc71 VJ	293	case CXL_IOCTL_GET_AFU_ID:
	294	return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
	295	arg);
f204e0b8 IM	296	}
	297	return -EINVAL;
	298	}
	299
3d6b040e	300	static long afu_compat_ioctl(struct file *file, unsigned int cmd,
f204e0b8 IM	301	unsigned long arg)
	302	{
	303	return afu_ioctl(file, cmd, arg);
	304	}
	305
0520336a	306	int afu_mmap(struct file file, struct vm_area_struct vm)
f204e0b8 IM	307	{
	308	struct cxl_context *ctx = file->private_data;
	309
	310	/* AFU must be started before we can MMIO */
	311	if (ctx->status != STARTED)
	312	return -EIO;
	313
0d400f77	314	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	315	return -EIO;
0b3f9c75 DA	316
f204e0b8 IM	317	return cxl_context_iomap(ctx, vm);
	318	}
	319
b810253b PB	320	static inline bool ctx_event_pending(struct cxl_context *ctx)
	321	{
	322	if (ctx->pending_irq \|\| ctx->pending_fault \|\| ctx->pending_afu_err)
	323	return true;
	324
	325	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))
	326	return true;
	327
	328	return false;
	329	}
	330
0520336a	331	unsigned int afu_poll(struct file file, struct poll_table_struct poll)
f204e0b8 IM	332	{
	333	struct cxl_context *ctx = file->private_data;
	334	int mask = 0;
	335	unsigned long flags;
	336
	337
	338	poll_wait(file, &ctx->wq, poll);
	339
	340	pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
	341
	342	spin_lock_irqsave(&ctx->lock, flags);
b810253b	343	if (ctx_event_pending(ctx))
f204e0b8 IM	344	mask \|= POLLIN \| POLLRDNORM;
	345	else if (ctx->status == CLOSED)
	346	/* Only error on closed when there are no futher events pending
	347	*/
	348	mask \|= POLLERR;
	349	spin_unlock_irqrestore(&ctx->lock, flags);
	350
	351	pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
	352
	353	return mask;
	354	}
	355
b810253b PB	356	static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
	357	char __user *buf,
	358	struct cxl_event *event,
	359	struct cxl_event_afu_driver_reserved *pl)
f204e0b8	360	{
b810253b PB	361	/* Check event */
	362	if (!pl) {
	363	ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
	364	return -EFAULT;
	365	}
	366
	367	/* Check event size */
	368	event->header.size += pl->data_size;
	369	if (event->header.size > CXL_READ_MIN_SIZE) {
	370	ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
	371	return -EFAULT;
	372	}
	373
	374	/* Copy event header */
	375	if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {
	376	ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
	377	return -EFAULT;
	378	}
	379
	380	/* Copy event data */
	381	buf += sizeof(struct cxl_event_header);
	382	if (copy_to_user(buf, &pl->data, pl->data_size)) {
	383	ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
	384	return -EFAULT;
	385	}
	386
	387	ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */
	388	return event->header.size;
f204e0b8 IM	389	}
f204e0b8 IM	390
0520336a	391	ssize_t afu_read(struct file file, char __user buf, size_t count,
f204e0b8 IM	392	loff_t *off)
	393	{
	394	struct cxl_context *ctx = file->private_data;
b810253b	395	struct cxl_event_afu_driver_reserved *pl = NULL;
f204e0b8 IM	396	struct cxl_event event;
f204e0b8 IM	397	unsigned long flags;
d53ba6b3	398	int rc;
f204e0b8 IM	399	DEFINE_WAIT(wait);
f204e0b8 IM	400
0d400f77	401	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	402	return -EIO;
0b3f9c75 DA	403
f204e0b8 IM	404	if (count < CXL_READ_MIN_SIZE)
	405	return -EINVAL;
	406
	407	spin_lock_irqsave(&ctx->lock, flags);
	408
	409	for (;;) {
	410	prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
b810253b	411	if (ctx_event_pending(ctx) \|\| (ctx->status == CLOSED))
f204e0b8 IM	412	break;
f204e0b8 IM	413
0d400f77	414	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
0b3f9c75 DA	415	rc = -EIO;
	416	goto out;
	417	}
	418
d53ba6b3 IM	419	if (file->f_flags & O_NONBLOCK) {
	420	rc = -EAGAIN;
	421	goto out;
	422	}
f204e0b8	423
d53ba6b3 IM	424	if (signal_pending(current)) {
	425	rc = -ERESTARTSYS;
	426	goto out;
	427	}
f204e0b8	428
d53ba6b3	429	spin_unlock_irqrestore(&ctx->lock, flags);
f204e0b8 IM	430	pr_devel("afu_read going to sleep...\n");
	431	schedule();
	432	pr_devel("afu_read woken up\n");
	433	spin_lock_irqsave(&ctx->lock, flags);
	434	}
	435
	436	finish_wait(&ctx->wq, &wait);
	437
	438	memset(&event, 0, sizeof(event));
	439	event.header.process_element = ctx->pe;
	440	event.header.size = sizeof(struct cxl_event_header);
b810253b PB	441	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) {
	442	pr_devel("afu_read delivering AFU driver specific event\n");
	443	pl = ctx->afu_driver_ops->fetch_event(ctx);
	444	atomic_dec(&ctx->afu_driver_events);
	445	event.header.type = CXL_EVENT_AFU_DRIVER;
	446	} else if (ctx->pending_irq) {
f204e0b8 IM	447	pr_devel("afu_read delivering AFU interrupt\n");
	448	event.header.size += sizeof(struct cxl_event_afu_interrupt);
	449	event.header.type = CXL_EVENT_AFU_INTERRUPT;
	450	event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
	451	clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
	452	if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
	453	ctx->pending_irq = false;
	454	} else if (ctx->pending_fault) {
	455	pr_devel("afu_read delivering data storage fault\n");
	456	event.header.size += sizeof(struct cxl_event_data_storage);
	457	event.header.type = CXL_EVENT_DATA_STORAGE;
	458	event.fault.addr = ctx->fault_addr;
	459	event.fault.dsisr = ctx->fault_dsisr;
	460	ctx->pending_fault = false;
	461	} else if (ctx->pending_afu_err) {
	462	pr_devel("afu_read delivering afu error\n");
	463	event.header.size += sizeof(struct cxl_event_afu_error);
	464	event.header.type = CXL_EVENT_AFU_ERROR;
	465	event.afu_error.error = ctx->afu_err;
	466	ctx->pending_afu_err = false;
	467	} else if (ctx->status == CLOSED) {
	468	pr_devel("afu_read fatal error\n");
	469	spin_unlock_irqrestore(&ctx->lock, flags);
	470	return -EIO;
	471	} else
	472	WARN(1, "afu_read must be buggy\n");
	473
	474	spin_unlock_irqrestore(&ctx->lock, flags);
	475
b810253b PB	476	if (event.header.type == CXL_EVENT_AFU_DRIVER)
	477	return afu_driver_event_copy(ctx, buf, &event, pl);
	478
f204e0b8 IM	479	if (copy_to_user(buf, &event, event.header.size))
	480	return -EFAULT;
	481	return event.header.size;
d53ba6b3 IM	482
	483	out:
	484	finish_wait(&ctx->wq, &wait);
	485	spin_unlock_irqrestore(&ctx->lock, flags);
	486	return rc;
f204e0b8 IM	487	}
f204e0b8 IM	488
0520336a MN	489	/*
	490	* Note: if this is updated, we need to update api.c to patch the new ones in
	491	* too
	492	*/
	493	const struct file_operations afu_fops = {
f204e0b8 IM	494	.owner = THIS_MODULE,
	495	.open = afu_open,
	496	.poll = afu_poll,
	497	.read = afu_read,
	498	.release = afu_release,
	499	.unlocked_ioctl = afu_ioctl,
	500	.compat_ioctl = afu_compat_ioctl,
	501	.mmap = afu_mmap,
	502	};
	503
3d6b040e	504	static const struct file_operations afu_master_fops = {
f204e0b8 IM	505	.owner = THIS_MODULE,
	506	.open = afu_master_open,
	507	.poll = afu_poll,
	508	.read = afu_read,
	509	.release = afu_release,
	510	.unlocked_ioctl = afu_ioctl,
	511	.compat_ioctl = afu_compat_ioctl,
	512	.mmap = afu_mmap,
	513	};
	514
	515
	516	static char cxl_devnode(struct device dev, umode_t *mode)
	517	{
594ff7d0 CL	518	if (cpu_has_feature(CPU_FTR_HVMODE) &&
594ff7d0 CL	519	CXL_DEVT_IS_CARD(dev->devt)) {
f204e0b8 IM	520	/*
	521	* These minor numbers will eventually be used to program the
	522	* PSL and AFUs once we have dynamic reprogramming support
	523	*/
	524	return NULL;
	525	}
	526	return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
	527	}
	528
	529	extern struct class *cxl_class;
	530
	531	static int cxl_add_chardev(struct cxl_afu afu, dev_t devt, struct cdev cdev,
	532	struct device *chardev, char postfix, char *desc,
	533	const struct file_operations *fops)
	534	{
	535	struct device *dev;
	536	int rc;
	537
	538	cdev_init(cdev, fops);
	539	if ((rc = cdev_add(cdev, devt, 1))) {
	540	dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
	541	return rc;
	542	}
	543
	544	dev = device_create(cxl_class, &afu->dev, devt, afu,
	545	"afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
	546	if (IS_ERR(dev)) {
	547	dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
	548	rc = PTR_ERR(dev);
	549	goto err;
	550	}
	551
	552	*chardev = dev;
	553
	554	return 0;
	555	err:
	556	cdev_del(cdev);
	557	return rc;
	558	}
	559
	560	int cxl_chardev_d_afu_add(struct cxl_afu *afu)
	561	{
	562	return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
	563	&afu->chardev_d, "d", "dedicated",
	564	&afu_master_fops); /* Uses master fops */
	565	}
	566
	567	int cxl_chardev_m_afu_add(struct cxl_afu *afu)
	568	{
	569	return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
	570	&afu->chardev_m, "m", "master",
	571	&afu_master_fops);
	572	}
	573
	574	int cxl_chardev_s_afu_add(struct cxl_afu *afu)
	575	{
	576	return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
	577	&afu->chardev_s, "s", "shared",
	578	&afu_fops);
	579	}
	580
	581	void cxl_chardev_afu_remove(struct cxl_afu *afu)
	582	{
	583	if (afu->chardev_d) {
584	cdev_del(&afu->afu_cdev_d);
585	device_unregister(afu->chardev_d);
586	afu->chardev_d = NULL;
587	}
588	if (afu->chardev_m) {
589	cdev_del(&afu->afu_cdev_m);
590	device_unregister(afu->chardev_m);
591	afu->chardev_m = NULL;
592	}
593	if (afu->chardev_s) {
594	cdev_del(&afu->afu_cdev_s);
595	device_unregister(afu->chardev_s);
596	afu->chardev_s = NULL;
597	}
598	}
599
600	int cxl_register_afu(struct cxl_afu *afu)
601	{
602	afu->dev.class = cxl_class;
603
604	return device_register(&afu->dev);
605	}
606
607	int cxl_register_adapter(struct cxl *adapter)
608	{
609	adapter->dev.class = cxl_class;
610
611	/*
612	* Future: When we support dynamically reprogramming the PSL & AFU we
613	* will expose the interface to do that via a chardev:
614	* adapter->dev.devt = CXL_CARD_MKDEV(adapter);
615	*/
616
617	return device_register(&adapter->dev);
618	}
619
594ff7d0 CL	620	dev_t cxl_get_dev(void)
	621	{
	622	return cxl_dev;
	623	}
	624
f204e0b8 IM	625	int __init cxl_file_init(void)
	626	{
	627	int rc;
	628
	629	/*
	630	* If these change we really need to update API. Either change some
	631	* flags or update API version number CXL_API_VERSION.
	632	*/
b810253b	633	BUILD_BUG_ON(CXL_API_VERSION != 3);
f204e0b8 IM	634	BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
	635	BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
	636	BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
	637	BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
	638	BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
	639
	640	if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
	641	pr_err("Unable to allocate CXL major number: %i\n", rc);
	642	return rc;
	643	}
	644
	645	pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
	646
	647	cxl_class = class_create(THIS_MODULE, "cxl");
	648	if (IS_ERR(cxl_class)) {
	649	pr_err("Unable to create CXL class\n");
	650	rc = PTR_ERR(cxl_class);
	651	goto err;
	652	}
	653	cxl_class->devnode = cxl_devnode;
	654
	655	return 0;
	656
	657	err:
	658	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
	659	return rc;
	660	}
	661
	662	void cxl_file_exit(void)
	663	{
	664	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
	665	class_destroy(cxl_class);
	666	}