[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);

	/*
	 * 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);
		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
f204e0b8 IM	196	/*
	197	* We grab the PID here and not in the file open to allow for the case
	198	* where a process (master, some daemon, etc) has opened the chardev on
	199	* behalf of another process, so the AFU's mm gets bound to the process
	200	* that performs this ioctl and not the process that opened the file.
7b8ad495 VJ	201	* Also we grab the PID of the group leader so that if the task that
	202	* has performed the attach operation exits the mm context of the
	203	* process is still accessible.
f204e0b8	204	*/
7b8ad495 VJ	205	ctx->pid = get_task_pid(current, PIDTYPE_PID);
7b8ad495 VJ	206	ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
f204e0b8	207
9bcf28cd IM	208	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
9bcf28cd IM	209
5be587b1 FB	210	if ((rc = cxl_ops->attach_process(ctx, false, work.work_element_descriptor,
5be587b1 FB	211	amr))) {
6428832a	212	afu_release_irqs(ctx, ctx);
f204e0b8	213	goto out;
456295e2	214	}
f204e0b8 IM	215
	216	ctx->status = STARTED;
	217	rc = 0;
	218	out:
	219	mutex_unlock(&ctx->status_mutex);
	220	return rc;
	221	}
5be587b1	222
f204e0b8 IM	223	static long afu_ioctl_process_element(struct cxl_context *ctx,
	224	int __user *upe)
	225	{
	226	pr_devel("%s: pe: %i\n", __func__, ctx->pe);
	227
14baf4d9	228	if (copy_to_user(upe, &ctx->external_pe, sizeof(__u32)))
f204e0b8 IM	229	return -EFAULT;
	230
	231	return 0;
	232	}
	233
27d4dc71 VJ	234	static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
	235	struct cxl_afu_id __user *upafuid)
	236	{
	237	struct cxl_afu_id afuid = { 0 };
	238
	239	afuid.card_id = ctx->afu->adapter->adapter_num;
	240	afuid.afu_offset = ctx->afu->slice;
	241	afuid.afu_mode = ctx->afu->current_mode;
	242
	243	/* set the flag bit in case the afu is a slave */
	244	if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
	245	afuid.flags \|= CXL_AFUID_FLAG_SLAVE;
	246
	247	if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
	248	return -EFAULT;
	249
	250	return 0;
	251	}
	252
0520336a	253	long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
f204e0b8 IM	254	{
	255	struct cxl_context *ctx = file->private_data;
	256
	257	if (ctx->status == CLOSED)
	258	return -EIO;
	259
0d400f77	260	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	261	return -EIO;
0b3f9c75 DA	262
f204e0b8 IM	263	pr_devel("afu_ioctl\n");
	264	switch (cmd) {
	265	case CXL_IOCTL_START_WORK:
	266	return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
	267	case CXL_IOCTL_GET_PROCESS_ELEMENT:
	268	return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
27d4dc71 VJ	269	case CXL_IOCTL_GET_AFU_ID:
	270	return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
	271	arg);
f204e0b8 IM	272	}
	273	return -EINVAL;
	274	}
	275
3d6b040e	276	static long afu_compat_ioctl(struct file *file, unsigned int cmd,
f204e0b8 IM	277	unsigned long arg)
	278	{
	279	return afu_ioctl(file, cmd, arg);
	280	}
	281
0520336a	282	int afu_mmap(struct file file, struct vm_area_struct vm)
f204e0b8 IM	283	{
	284	struct cxl_context *ctx = file->private_data;
	285
	286	/* AFU must be started before we can MMIO */
	287	if (ctx->status != STARTED)
	288	return -EIO;
	289
0d400f77	290	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	291	return -EIO;
0b3f9c75 DA	292
f204e0b8 IM	293	return cxl_context_iomap(ctx, vm);
	294	}
	295
b810253b PB	296	static inline bool ctx_event_pending(struct cxl_context *ctx)
	297	{
	298	if (ctx->pending_irq \|\| ctx->pending_fault \|\| ctx->pending_afu_err)
	299	return true;
	300
	301	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events))
	302	return true;
	303
	304	return false;
	305	}
	306
0520336a	307	unsigned int afu_poll(struct file file, struct poll_table_struct poll)
f204e0b8 IM	308	{
	309	struct cxl_context *ctx = file->private_data;
	310	int mask = 0;
	311	unsigned long flags;
	312
	313
	314	poll_wait(file, &ctx->wq, poll);
	315
	316	pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
	317
	318	spin_lock_irqsave(&ctx->lock, flags);
b810253b	319	if (ctx_event_pending(ctx))
f204e0b8 IM	320	mask \|= POLLIN \| POLLRDNORM;
	321	else if (ctx->status == CLOSED)
	322	/* Only error on closed when there are no futher events pending
	323	*/
	324	mask \|= POLLERR;
	325	spin_unlock_irqrestore(&ctx->lock, flags);
	326
	327	pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
	328
	329	return mask;
	330	}
	331
b810253b PB	332	static ssize_t afu_driver_event_copy(struct cxl_context *ctx,
	333	char __user *buf,
	334	struct cxl_event *event,
	335	struct cxl_event_afu_driver_reserved *pl)
f204e0b8	336	{
b810253b PB	337	/* Check event */
	338	if (!pl) {
	339	ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
	340	return -EFAULT;
	341	}
	342
	343	/* Check event size */
	344	event->header.size += pl->data_size;
	345	if (event->header.size > CXL_READ_MIN_SIZE) {
	346	ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL);
	347	return -EFAULT;
	348	}
	349
	350	/* Copy event header */
	351	if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) {
	352	ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
	353	return -EFAULT;
	354	}
	355
	356	/* Copy event data */
	357	buf += sizeof(struct cxl_event_header);
	358	if (copy_to_user(buf, &pl->data, pl->data_size)) {
	359	ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT);
	360	return -EFAULT;
	361	}
	362
	363	ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */
	364	return event->header.size;
f204e0b8 IM	365	}
f204e0b8 IM	366
0520336a	367	ssize_t afu_read(struct file file, char __user buf, size_t count,
f204e0b8 IM	368	loff_t *off)
	369	{
	370	struct cxl_context *ctx = file->private_data;
b810253b	371	struct cxl_event_afu_driver_reserved *pl = NULL;
f204e0b8 IM	372	struct cxl_event event;
f204e0b8 IM	373	unsigned long flags;
d53ba6b3	374	int rc;
f204e0b8 IM	375	DEFINE_WAIT(wait);
f204e0b8 IM	376
0d400f77	377	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu))
0b3f9c75 DA	378	return -EIO;
0b3f9c75 DA	379
f204e0b8 IM	380	if (count < CXL_READ_MIN_SIZE)
	381	return -EINVAL;
	382
	383	spin_lock_irqsave(&ctx->lock, flags);
	384
	385	for (;;) {
	386	prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
b810253b	387	if (ctx_event_pending(ctx) \|\| (ctx->status == CLOSED))
f204e0b8 IM	388	break;
f204e0b8 IM	389
0d400f77	390	if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) {
0b3f9c75 DA	391	rc = -EIO;
	392	goto out;
	393	}
	394
d53ba6b3 IM	395	if (file->f_flags & O_NONBLOCK) {
	396	rc = -EAGAIN;
	397	goto out;
	398	}
f204e0b8	399
d53ba6b3 IM	400	if (signal_pending(current)) {
	401	rc = -ERESTARTSYS;
	402	goto out;
	403	}
f204e0b8	404
d53ba6b3	405	spin_unlock_irqrestore(&ctx->lock, flags);
f204e0b8 IM	406	pr_devel("afu_read going to sleep...\n");
	407	schedule();
	408	pr_devel("afu_read woken up\n");
	409	spin_lock_irqsave(&ctx->lock, flags);
	410	}
	411
	412	finish_wait(&ctx->wq, &wait);
	413
	414	memset(&event, 0, sizeof(event));
	415	event.header.process_element = ctx->pe;
	416	event.header.size = sizeof(struct cxl_event_header);
b810253b PB	417	if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) {
	418	pr_devel("afu_read delivering AFU driver specific event\n");
	419	pl = ctx->afu_driver_ops->fetch_event(ctx);
	420	atomic_dec(&ctx->afu_driver_events);
	421	event.header.type = CXL_EVENT_AFU_DRIVER;
	422	} else if (ctx->pending_irq) {
f204e0b8 IM	423	pr_devel("afu_read delivering AFU interrupt\n");
	424	event.header.size += sizeof(struct cxl_event_afu_interrupt);
	425	event.header.type = CXL_EVENT_AFU_INTERRUPT;
	426	event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
	427	clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
	428	if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
	429	ctx->pending_irq = false;
	430	} else if (ctx->pending_fault) {
	431	pr_devel("afu_read delivering data storage fault\n");
	432	event.header.size += sizeof(struct cxl_event_data_storage);
	433	event.header.type = CXL_EVENT_DATA_STORAGE;
	434	event.fault.addr = ctx->fault_addr;
	435	event.fault.dsisr = ctx->fault_dsisr;
	436	ctx->pending_fault = false;
	437	} else if (ctx->pending_afu_err) {
	438	pr_devel("afu_read delivering afu error\n");
	439	event.header.size += sizeof(struct cxl_event_afu_error);
	440	event.header.type = CXL_EVENT_AFU_ERROR;
	441	event.afu_error.error = ctx->afu_err;
	442	ctx->pending_afu_err = false;
	443	} else if (ctx->status == CLOSED) {
	444	pr_devel("afu_read fatal error\n");
	445	spin_unlock_irqrestore(&ctx->lock, flags);
	446	return -EIO;
	447	} else
	448	WARN(1, "afu_read must be buggy\n");
	449
	450	spin_unlock_irqrestore(&ctx->lock, flags);
	451
b810253b PB	452	if (event.header.type == CXL_EVENT_AFU_DRIVER)
	453	return afu_driver_event_copy(ctx, buf, &event, pl);
	454
f204e0b8 IM	455	if (copy_to_user(buf, &event, event.header.size))
	456	return -EFAULT;
	457	return event.header.size;
d53ba6b3 IM	458
	459	out:
	460	finish_wait(&ctx->wq, &wait);
	461	spin_unlock_irqrestore(&ctx->lock, flags);
	462	return rc;
f204e0b8 IM	463	}
f204e0b8 IM	464
0520336a MN	465	/*
	466	* Note: if this is updated, we need to update api.c to patch the new ones in
	467	* too
	468	*/
	469	const struct file_operations afu_fops = {
f204e0b8 IM	470	.owner = THIS_MODULE,
	471	.open = afu_open,
	472	.poll = afu_poll,
	473	.read = afu_read,
	474	.release = afu_release,
	475	.unlocked_ioctl = afu_ioctl,
	476	.compat_ioctl = afu_compat_ioctl,
	477	.mmap = afu_mmap,
	478	};
	479
3d6b040e	480	static const struct file_operations afu_master_fops = {
f204e0b8 IM	481	.owner = THIS_MODULE,
	482	.open = afu_master_open,
	483	.poll = afu_poll,
	484	.read = afu_read,
	485	.release = afu_release,
	486	.unlocked_ioctl = afu_ioctl,
	487	.compat_ioctl = afu_compat_ioctl,
	488	.mmap = afu_mmap,
	489	};
	490
	491
	492	static char cxl_devnode(struct device dev, umode_t *mode)
	493	{
594ff7d0 CL	494	if (cpu_has_feature(CPU_FTR_HVMODE) &&
594ff7d0 CL	495	CXL_DEVT_IS_CARD(dev->devt)) {
f204e0b8 IM	496	/*
	497	* These minor numbers will eventually be used to program the
	498	* PSL and AFUs once we have dynamic reprogramming support
	499	*/
	500	return NULL;
	501	}
	502	return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
	503	}
	504
	505	extern struct class *cxl_class;
	506
	507	static int cxl_add_chardev(struct cxl_afu afu, dev_t devt, struct cdev cdev,
	508	struct device *chardev, char postfix, char *desc,
	509	const struct file_operations *fops)
	510	{
	511	struct device *dev;
	512	int rc;
	513
	514	cdev_init(cdev, fops);
	515	if ((rc = cdev_add(cdev, devt, 1))) {
	516	dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
	517	return rc;
	518	}
	519
	520	dev = device_create(cxl_class, &afu->dev, devt, afu,
	521	"afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
	522	if (IS_ERR(dev)) {
	523	dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
	524	rc = PTR_ERR(dev);
	525	goto err;
	526	}
	527
	528	*chardev = dev;
	529
	530	return 0;
	531	err:
	532	cdev_del(cdev);
	533	return rc;
	534	}
	535
	536	int cxl_chardev_d_afu_add(struct cxl_afu *afu)
	537	{
	538	return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
	539	&afu->chardev_d, "d", "dedicated",
	540	&afu_master_fops); /* Uses master fops */
	541	}
	542
	543	int cxl_chardev_m_afu_add(struct cxl_afu *afu)
	544	{
	545	return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
	546	&afu->chardev_m, "m", "master",
	547	&afu_master_fops);
	548	}
	549
	550	int cxl_chardev_s_afu_add(struct cxl_afu *afu)
	551	{
	552	return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
	553	&afu->chardev_s, "s", "shared",
	554	&afu_fops);
	555	}
	556
	557	void cxl_chardev_afu_remove(struct cxl_afu *afu)
	558	{
	559	if (afu->chardev_d) {
560	cdev_del(&afu->afu_cdev_d);
561	device_unregister(afu->chardev_d);
562	afu->chardev_d = NULL;
563	}
564	if (afu->chardev_m) {
565	cdev_del(&afu->afu_cdev_m);
566	device_unregister(afu->chardev_m);
567	afu->chardev_m = NULL;
568	}
569	if (afu->chardev_s) {
570	cdev_del(&afu->afu_cdev_s);
571	device_unregister(afu->chardev_s);
572	afu->chardev_s = NULL;
573	}
574	}
575
576	int cxl_register_afu(struct cxl_afu *afu)
577	{
578	afu->dev.class = cxl_class;
579
580	return device_register(&afu->dev);
581	}
582
583	int cxl_register_adapter(struct cxl *adapter)
584	{
585	adapter->dev.class = cxl_class;
586
587	/*
588	* Future: When we support dynamically reprogramming the PSL & AFU we
589	* will expose the interface to do that via a chardev:
590	* adapter->dev.devt = CXL_CARD_MKDEV(adapter);
591	*/
592
593	return device_register(&adapter->dev);
594	}
595
594ff7d0 CL	596	dev_t cxl_get_dev(void)
	597	{
	598	return cxl_dev;
	599	}
	600
f204e0b8 IM	601	int __init cxl_file_init(void)
	602	{
	603	int rc;
	604
	605	/*
	606	* If these change we really need to update API. Either change some
	607	* flags or update API version number CXL_API_VERSION.
	608	*/
b810253b	609	BUILD_BUG_ON(CXL_API_VERSION != 3);
f204e0b8 IM	610	BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
	611	BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
	612	BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
	613	BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
	614	BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
	615
	616	if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
	617	pr_err("Unable to allocate CXL major number: %i\n", rc);
	618	return rc;
	619	}
	620
	621	pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
	622
	623	cxl_class = class_create(THIS_MODULE, "cxl");
	624	if (IS_ERR(cxl_class)) {
	625	pr_err("Unable to create CXL class\n");
	626	rc = PTR_ERR(cxl_class);
	627	goto err;
	628	}
	629	cxl_class->devnode = cxl_devnode;
	630
	631	return 0;
	632
	633	err:
	634	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
	635	return rc;
	636	}
	637
	638	void cxl_file_exit(void)
	639	{
	640	unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
	641	class_destroy(cxl_class);
	642	}