[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.h>
#include <linux/poll.h>
#include <linux/pid.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.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;
	}

	if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping)))
		goto err_put_afu;

	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(struct cxl_ioctl_start_work))) {
		rc = -EFAULT;
		goto out;
	}

	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);
	ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);


	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->glpid);
		put_pid(ctx->pid);
		ctx->glpid = ctx->pid = NULL;
		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>
	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"
9bcf28cd	26	#include "trace.h"
f204e0b8 IM	27
f204e0b8 IM	28	#define CXL_NUM_MINORS 256 /* Total to reserve */
f204e0b8	29
f204e0b8 IM	30	#define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
	31	#define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
	32	#define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
	33	#define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))
	34	#define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
	35	#define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))
	36
f204e0b8 IM	37	#define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
	38
	39	#define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
	40
	41	static dev_t cxl_dev;
	42
	43	static struct class *cxl_class;
	44
	45	static int __afu_open(struct inode inode, struct file file, bool master)
	46	{
	47	struct cxl *adapter;
	48	struct cxl_afu *afu;
	49	struct cxl_context *ctx;
	50	int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
	51	int slice = CXL_DEVT_AFU(inode->i_rdev);
	52	int rc = -ENODEV;
	53
	54	pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
	55
	56	if (!(adapter = get_cxl_adapter(adapter_num)))
	57	return -ENODEV;
	58
	59	if (slice > adapter->slices)
	60	goto err_put_adapter;
	61
	62	spin_lock(&adapter->afu_list_lock);
	63	if (!(afu = adapter->afu[slice])) {
	64	spin_unlock(&adapter->afu_list_lock);
	65	goto err_put_adapter;
	66	}
1b5df59e VJ	67
	68	/*
	69	* taking a ref to the afu so that it doesn't go away
	70	* for rest of the function. This ref is released before
	71	* we return.
	72	*/
	73	cxl_afu_get(afu);
f204e0b8 IM	74	spin_unlock(&adapter->afu_list_lock);
	75
	76	if (!afu->current_mode)
	77	goto err_put_afu;
	78
0d400f77	79	if (!cxl_ops->link_ok(adapter, afu)) {
0b3f9c75 DA	80	rc = -EIO;
	81	goto err_put_afu;
	82	}
	83
f204e0b8 IM	84	if (!(ctx = cxl_context_alloc())) {
	85	rc = -ENOMEM;
	86	goto err_put_afu;
	87	}
	88
b123429e	89	if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping)))
f204e0b8 IM	90	goto err_put_afu;
	91
	92	pr_devel("afu_open pe: %i\n", ctx->pe);
	93	file->private_data = ctx;
	94	cxl_ctx_get();
	95
1b5df59e VJ	96	/* indicate success */
1b5df59e VJ	97	rc = 0;
f204e0b8 IM	98
f204e0b8 IM	99	err_put_afu:
1b5df59e VJ	100	/* release the ref taken earlier */
1b5df59e VJ	101	cxl_afu_put(afu);
f204e0b8 IM	102	err_put_adapter:
	103	put_device(&adapter->dev);
	104	return rc;
	105	}
0520336a MN	106
0520336a MN	107	int afu_open(struct inode inode, struct file file)
f204e0b8 IM	108	{
	109	return __afu_open(inode, file, false);
	110	}
	111
	112	static int afu_master_open(struct inode inode, struct file file)
	113	{
	114	return __afu_open(inode, file, true);
	115	}
	116
0520336a	117	int afu_release(struct inode inode, struct file file)
f204e0b8 IM	118	{
	119	struct cxl_context *ctx = file->private_data;
	120
	121	pr_devel("%s: closing cxl file descriptor. pe: %i\n",
	122	__func__, ctx->pe);
	123	cxl_context_detach(ctx);
	124
5f81b95f AD	125
	126	/*
	127	* Delete the context's mapping pointer, unless it's created by the
	128	* kernel API, in which case leave it so it can be freed by reclaim_ctx()
	129	*/
	130	if (!ctx->kernelapi) {
	131	mutex_lock(&ctx->mapping_lock);
	132	ctx->mapping = NULL;
	133	mutex_unlock(&ctx->mapping_lock);
	134	}
b123429e	135
f204e0b8 IM	136	/*
	137	* At this this point all bottom halfs have finished and we should be
	138	* getting no more IRQs from the hardware for this context. Once it's
	139	* removed from the IDR (and RCU synchronised) it's safe to free the
	140	* sstp and context.
	141	*/
	142	cxl_context_free(ctx);
	143
f204e0b8 IM	144	return 0;
	145	}
	146
	147	static long afu_ioctl_start_work(struct cxl_context *ctx,
	148	struct cxl_ioctl_start_work __user *uwork)
	149	{
	150	struct cxl_ioctl_start_work work;
	151	u64 amr = 0;
	152	int rc;
	153
	154	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
	155
0712dc7e IM	156	/* Do this outside the status_mutex to avoid a circular dependency with
0712dc7e IM	157	* the locking in cxl_mmap_fault() */
f204e0b8 IM	158	if (copy_from_user(&work, uwork,
	159	sizeof(struct cxl_ioctl_start_work))) {
	160	rc = -EFAULT;
	161	goto out;
	162	}
	163
0712dc7e IM	164	mutex_lock(&ctx->status_mutex);
	165	if (ctx->status != OPENED) {
	166	rc = -EIO;
	167	goto out;
	168	}
	169
f204e0b8 IM	170	/*
	171	* if any of the reserved fields are set or any of the unused
	172	* flags are set it's invalid
	173	*/
	174	if (work.reserved1 \|\| work.reserved2 \|\| work.reserved3 \|\|
	175	work.reserved4 \|\| work.reserved5 \|\| work.reserved6 \|\|
	176	(work.flags & ~CXL_START_WORK_ALL)) {
	177	rc = -EINVAL;
	178	goto out;
	179	}
	180
	181	if (!(work.flags & CXL_START_WORK_NUM_IRQS))
	182	work.num_interrupts = ctx->afu->pp_irqs;
	183	else if ((work.num_interrupts < ctx->afu->pp_irqs) \|\|
	184	(work.num_interrupts > ctx->afu->irqs_max)) {
	185	rc = -EINVAL;
	186	goto out;
	187	}
	188	if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
	189	goto out;
	190
	191	if (work.flags & CXL_START_WORK_AMR)
	192	amr = work.amr & mfspr(SPRN_UAMOR);
	193
d9232a3d IM	194	ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
d9232a3d IM	195
a05b82d5 VJ	196	/*
	197	* Increment the mapped context count for adapter. This also checks
	198	* if adapter_context_lock is taken.
	199	*/
	200	rc = cxl_adapter_context_get(ctx->afu->adapter);
	201	if (rc) {
	202	afu_release_irqs(ctx, ctx);
	203	goto out;
	204	}
	205
f204e0b8 IM	206	/*
	207	* We grab the PID here and not in the file open to allow for the case
	208	* where a process (master, some daemon, etc) has opened the chardev on
	209	* behalf of another process, so the AFU's mm gets bound to the process
	210	* that performs this ioctl and not the process that opened the file.
7b8ad495 VJ	211	* Also we grab the PID of the group leader so that if the task that
	212	* has performed the attach operation exits the mm context of the
	213	* process is still accessible.
f204e0b8	214	*/
7b8ad495 VJ	215	ctx->pid = get_task_pid(current, PIDTYPE_PID);
7b8ad495 VJ	216	ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
f204e0b8	217
70b565bb	218
9bcf28cd IM	219	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
9bcf28cd IM	220
5be587b1 FB	221	if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
5be587b1 FB	222	amr))) {
6428832a	223	afu_release_irqs(ctx, ctx);
70b565bb	224	cxl_adapter_context_put(ctx->afu->adapter);
a05b82d5 VJ	225	put_pid(ctx->glpid);
	226	put_pid(ctx->pid);
	227	ctx->glpid = ctx->pid = NULL;
f204e0b8	228	goto out;
456295e2	229	}
f204e0b8 IM	230
	231	ctx->status = STARTED;
	232	rc = 0;
	233	out:
	234	mutex_unlock(&ctx->status_mutex);
	235	return rc;
	236	}
5be587b1	237
f204e0b8 IM	238	static long afu_ioctl_process_element(struct cxl_context *ctx,
	239	int __user *upe)
	240	{
	241	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
	242
14baf4d9	243	if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
f204e0b8 IM	244	return -EFAULT;
	245
	246	return 0;
	247	}
	248
27d4dc71 VJ	249	static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
	250	struct cxl_afu_id __user *upafuid)
	251	{
	252	struct cxl_afu_id afuid = { 0 };
	253
	254	afuid.card_id = ctx->afu->adapter->adapter_num;
	255	afuid.afu_offset = ctx->afu->slice;
	256	afuid.afu_mode = ctx->afu->current_mode;
	257
	258	/* set the flag bit in case the afu is a slave */
	259	if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
	260	afuid.flags \|= CXL_AFUID_FLAG_SLAVE;
	261
	262	if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
	263	return -EFAULT;
	264
	265	return 0;
	266	}
	267
0520336a	268	long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
f204e0b8 IM	269	{
	270	struct cxl_context *ctx = file->private_data;
	271
	272	if (ctx->status == CLOSED)
	273	return -EIO;
	274
0d400f77	275	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	276	return -EIO;
0b3f9c75 DA	277
f204e0b8 IM	278	pr_devel("afu_ioctl\n");
	279	switch (cmd) {
	280	case CXL_IOCTL_START_WORK:
	281	return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
	282	case CXL_IOCTL_GET_PROCESS_ELEMENT:
	283	return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
27d4dc71 VJ	284	case CXL_IOCTL_GET_AFU_ID:
	285	return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
	286	arg);
f204e0b8 IM	287	}
	288	return -EINVAL;
	289	}
	290
3d6b040e	291	static long afu_compat_ioctl(struct file *file, unsigned int cmd,
f204e0b8 IM	292	unsigned long arg)
	293	{
	294	return afu_ioctl(file, cmd, arg);
	295	}
	296
0520336a	297	int afu_mmap(struct file file, struct vm_area_struct vm)
f204e0b8 IM	298	{
	299	struct cxl_context *ctx = file->private_data;
	300
	301	/* AFU must be started before we can MMIO */
	302	if (ctx->status != STARTED)
	303	return -EIO;
	304
0d400f77	305	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	306	return -EIO;
0b3f9c75 DA	307
f204e0b8 IM	308	return cxl_context_iomap(ctx, vm);
	309	}
	310
b810253b PB	311	static inline bool ctx_event_pending(struct cxl_context *ctx)
	312	{
	313	if (ctx->pending_irq \|\| ctx->pending_fault \|\| ctx->pending_afu_err)
	314	return true;
	315
	316	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))
	317	return true;
	318
	319	return false;
	320	}
	321
0520336a	322	unsigned int afu_poll(struct file file, struct poll_table_struct poll)
f204e0b8 IM	323	{
	324	struct cxl_context *ctx = file->private_data;
	325	int mask = 0;
	326	unsigned long flags;
	327
	328
	329	poll_wait(file, &ctx->wq, poll);
	330
	331	pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
	332
	333	spin_lock_irqsave(&ctx->lock, flags);
b810253b	334	if (ctx_event_pending(ctx))
f204e0b8 IM	335	mask \|= POLLIN \| POLLRDNORM;
	336	else if (ctx->status == CLOSED)
	337	/* Only error on closed when there are no futher events pending
	338	*/
	339	mask \|= POLLERR;
	340	spin_unlock_irqrestore(&ctx->lock, flags);
	341
	342	pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
	343
	344	return mask;
	345	}
	346
b810253b PB	347	static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
	348	char __user *buf,
	349	struct cxl_event *event,
	350	struct cxl_event_afu_driver_reserved *pl)
f204e0b8	351	{
b810253b PB	352	/* Check event */
	353	if (!pl) {
	354	ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
	355	return -EFAULT;
	356	}
	357
	358	/* Check event size */
	359	event->header.size += pl->data_size;
	360	if (event->header.size > CXL_READ_MIN_SIZE) {
	361	ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
	362	return -EFAULT;
	363	}
	364
	365	/* Copy event header */
	366	if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {
	367	ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
	368	return -EFAULT;
	369	}
	370
	371	/* Copy event data */
	372	buf += sizeof(struct cxl_event_header);
	373	if (copy_to_user(buf, &pl->data, pl->data_size)) {
	374	ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
	375	return -EFAULT;
	376	}
	377
	378	ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */
	379	return event->header.size;
f204e0b8 IM	380	}
f204e0b8 IM	381
0520336a	382	ssize_t afu_read(struct file file, char __user buf, size_t count,
f204e0b8 IM	383	loff_t *off)
	384	{
	385	struct cxl_context *ctx = file->private_data;
b810253b	386	struct cxl_event_afu_driver_reserved *pl = NULL;
f204e0b8 IM	387	struct cxl_event event;
f204e0b8 IM	388	unsigned long flags;
d53ba6b3	389	int rc;
f204e0b8 IM	390	DEFINE_WAIT(wait);
f204e0b8 IM	391
0d400f77	392	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	393	return -EIO;
0b3f9c75 DA	394
f204e0b8 IM	395	if (count < CXL_READ_MIN_SIZE)
	396	return -EINVAL;
	397
	398	spin_lock_irqsave(&ctx->lock, flags);
	399
	400	for (;;) {
	401	prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
b810253b	402	if (ctx_event_pending(ctx) \|\| (ctx->status == CLOSED))
f204e0b8 IM	403	break;
f204e0b8 IM	404
0d400f77	405	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
0b3f9c75 DA	406	rc = -EIO;
	407	goto out;
	408	}
	409
d53ba6b3 IM	410	if (file->f_flags & O_NONBLOCK) {
	411	rc = -EAGAIN;
	412	goto out;
	413	}
f204e0b8	414
d53ba6b3 IM	415	if (signal_pending(current)) {
	416	rc = -ERESTARTSYS;
	417	goto out;
	418	}
f204e0b8	419
d53ba6b3	420	spin_unlock_irqrestore(&ctx->lock, flags);
f204e0b8 IM	421	pr_devel("afu_read going to sleep...\n");
	422	schedule();
	423	pr_devel("afu_read woken up\n");
	424	spin_lock_irqsave(&ctx->lock, flags);
	425	}
	426
	427	finish_wait(&ctx->wq, &wait);
	428
	429	memset(&event, 0, sizeof(event));
	430	event.header.process_element = ctx->pe;
	431	event.header.size = sizeof(struct cxl_event_header);
b810253b PB	432	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) {
	433	pr_devel("afu_read delivering AFU driver specific event\n");
	434	pl = ctx->afu_driver_ops->fetch_event(ctx);
	435	atomic_dec(&ctx->afu_driver_events);
	436	event.header.type = CXL_EVENT_AFU_DRIVER;
	437	} else if (ctx->pending_irq) {
f204e0b8 IM	438	pr_devel("afu_read delivering AFU interrupt\n");
	439	event.header.size += sizeof(struct cxl_event_afu_interrupt);
	440	event.header.type = CXL_EVENT_AFU_INTERRUPT;
	441	event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
	442	clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
	443	if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
	444	ctx->pending_irq = false;
	445	} else if (ctx->pending_fault) {
	446	pr_devel("afu_read delivering data storage fault\n");
	447	event.header.size += sizeof(struct cxl_event_data_storage);
	448	event.header.type = CXL_EVENT_DATA_STORAGE;
	449	event.fault.addr = ctx->fault_addr;
	450	event.fault.dsisr = ctx->fault_dsisr;
	451	ctx->pending_fault = false;
	452	} else if (ctx->pending_afu_err) {
	453	pr_devel("afu_read delivering afu error\n");
	454	event.header.size += sizeof(struct cxl_event_afu_error);
	455	event.header.type = CXL_EVENT_AFU_ERROR;
	456	event.afu_error.error = ctx->afu_err;
	457	ctx->pending_afu_err = false;
	458	} else if (ctx->status == CLOSED) {
	459	pr_devel("afu_read fatal error\n");
	460	spin_unlock_irqrestore(&ctx->lock, flags);
	461	return -EIO;
	462	} else
	463	WARN(1, "afu_read must be buggy\n");
	464
	465	spin_unlock_irqrestore(&ctx->lock, flags);
	466
b810253b PB	467	if (event.header.type == CXL_EVENT_AFU_DRIVER)
	468	return afu_driver_event_copy(ctx, buf, &event, pl);
	469
f204e0b8 IM	470	if (copy_to_user(buf, &event, event.header.size))
	471	return -EFAULT;
	472	return event.header.size;
d53ba6b3 IM	473
	474	out:
	475	finish_wait(&ctx->wq, &wait);
	476	spin_unlock_irqrestore(&ctx->lock, flags);
	477	return rc;
f204e0b8 IM	478	}
f204e0b8 IM	479
0520336a MN	480	/*
	481	* Note: if this is updated, we need to update api.c to patch the new ones in
	482	* too
	483	*/
	484	const struct file_operations afu_fops = {
f204e0b8 IM	485	.owner = THIS_MODULE,
	486	.open = afu_open,
	487	.poll = afu_poll,
	488	.read = afu_read,
	489	.release = afu_release,
	490	.unlocked_ioctl = afu_ioctl,
	491	.compat_ioctl = afu_compat_ioctl,
	492	.mmap = afu_mmap,
	493	};
	494
3d6b040e	495	static const struct file_operations afu_master_fops = {
f204e0b8 IM	496	.owner = THIS_MODULE,
	497	.open = afu_master_open,
	498	.poll = afu_poll,
	499	.read = afu_read,
	500	.release = afu_release,
	501	.unlocked_ioctl = afu_ioctl,
	502	.compat_ioctl = afu_compat_ioctl,
	503	.mmap = afu_mmap,
	504	};
	505
	506
	507	static char cxl_devnode(struct device dev, umode_t *mode)
	508	{
594ff7d0 CL	509	if (cpu_has_feature(CPU_FTR_HVMODE) &&
594ff7d0 CL	510	CXL_DEVT_IS_CARD(dev->devt)) {
f204e0b8 IM	511	/*
	512	* These minor numbers will eventually be used to program the
	513	* PSL and AFUs once we have dynamic reprogramming support
	514	*/
	515	return NULL;
	516	}
	517	return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
	518	}
	519
	520	extern struct class *cxl_class;
	521
	522	static int cxl_add_chardev(struct cxl_afu afu, dev_t devt, struct cdev cdev,
	523	struct device *chardev, char postfix, char *desc,
	524	const struct file_operations *fops)
	525	{
	526	struct device *dev;
	527	int rc;
	528
	529	cdev_init(cdev, fops);
	530	if ((rc = cdev_add(cdev, devt, 1))) {
	531	dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
	532	return rc;
	533	}
	534
	535	dev = device_create(cxl_class, &afu->dev, devt, afu,
	536	"afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
	537	if (IS_ERR(dev)) {
	538	dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
	539	rc = PTR_ERR(dev);
	540	goto err;
	541	}
	542
	543	*chardev = dev;
	544
	545	return 0;
	546	err:
	547	cdev_del(cdev);
	548	return rc;
	549	}
	550
	551	int cxl_chardev_d_afu_add(struct cxl_afu *afu)
	552	{
	553	return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
	554	&afu->chardev_d, "d", "dedicated",
	555	&afu_master_fops); /* Uses master fops */
	556	}
	557
	558	int cxl_chardev_m_afu_add(struct cxl_afu *afu)
	559	{
	560	return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
	561	&afu->chardev_m, "m", "master",
	562	&afu_master_fops);
	563	}
	564
	565	int cxl_chardev_s_afu_add(struct cxl_afu *afu)
	566	{
	567	return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
	568	&afu->chardev_s, "s", "shared",
	569	&afu_fops);
	570	}
	571
	572	void cxl_chardev_afu_remove(struct cxl_afu *afu)
	573	{
	574	if (afu->chardev_d) {
575	cdev_del(&afu->afu_cdev_d);
576	device_unregister(afu->chardev_d);
577	afu->chardev_d = NULL;
578	}
579	if (afu->chardev_m) {
580	cdev_del(&afu->afu_cdev_m);
581	device_unregister(afu->chardev_m);
582	afu->chardev_m = NULL;
583	}
584	if (afu->chardev_s) {
585	cdev_del(&afu->afu_cdev_s);
586	device_unregister(afu->chardev_s);
587	afu->chardev_s = NULL;
588	}
589	}
590
591	int cxl_register_afu(struct cxl_afu *afu)
592	{
593	afu->dev.class = cxl_class;
594
595	return device_register(&afu->dev);
596	}
597
598	int cxl_register_adapter(struct cxl *adapter)
599	{
600	adapter->dev.class = cxl_class;
601
602	/*
603	* Future: When we support dynamically reprogramming the PSL & AFU we
604	* will expose the interface to do that via a chardev:
605	* adapter->dev.devt = CXL_CARD_MKDEV(adapter);
606	*/
607
608	return device_register(&adapter->dev);
609	}
610
594ff7d0 CL	611	dev_t cxl_get_dev(void)
	612	{
	613	return cxl_dev;
	614	}
	615
f204e0b8 IM	616	int __init cxl_file_init(void)
	617	{
	618	int rc;
	619
	620	/*
	621	* If these change we really need to update API. Either change some
	622	* flags or update API version number CXL_API_VERSION.
	623	*/
b810253b	624	BUILD_BUG_ON(CXL_API_VERSION != 3);
f204e0b8 IM	625	BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
	626	BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
	627	BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
	628	BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
	629	BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
	630
	631	if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
	632	pr_err("Unable to allocate CXL major number: %i\n", rc);
	633	return rc;
	634	}
	635
	636	pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
	637
	638	cxl_class = class_create(THIS_MODULE, "cxl");
	639	if (IS_ERR(cxl_class)) {
	640	pr_err("Unable to create CXL class\n");
	641	rc = PTR_ERR(cxl_class);
	642	goto err;
	643	}
	644	cxl_class->devnode = cxl_devnode;
	645
	646	return 0;
	647
	648	err:
	649	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
	650	return rc;
	651	}
	652
	653	void cxl_file_exit(void)
	654	{
	655	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
	656	class_destroy(cxl_class);
	657	}