path: root/drivers/staging/rdma/hfi1/file_ops.c

/*
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2015 Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2015 Intel Corporation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  - Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  - Neither the name of Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
#include <linux/pci.h>
#include <linux/poll.h>
#include <linux/cdev.h>
#include <linux/swap.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <asm/pgtable.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/cred.h>
#include <linux/uio.h>

#include "hfi.h"
#include "pio.h"
#include "device.h"
#include "common.h"
#include "trace.h"
#include "user_sdma.h"
#include "eprom.h"

#undef pr_fmt
#define pr_fmt(fmt) DRIVER_NAME ": " fmt

#define SEND_CTXT_HALT_TIMEOUT 1000 /* msecs */

/*
 * File operation functions
 */
static int hfi1_file_open(struct inode *, struct file *);
static int hfi1_file_close(struct inode *, struct file *);
static ssize_t hfi1_file_write(struct file *, const char __user *,
			       size_t, loff_t *);
static ssize_t hfi1_write_iter(struct kiocb *, struct iov_iter *);
static unsigned int hfi1_poll(struct file *, struct poll_table_struct *);
static int hfi1_file_mmap(struct file *, struct vm_area_struct *);

static u64 kvirt_to_phys(void *);
static int assign_ctxt(struct file *, struct hfi1_user_info *);
static int init_subctxts(struct hfi1_ctxtdata *, const struct hfi1_user_info *);
static int user_init(struct file *);
static int get_ctxt_info(struct file *, void __user *, __u32);
static int get_base_info(struct file *, void __user *, __u32);
static int setup_ctxt(struct file *);
static int setup_subctxt(struct hfi1_ctxtdata *);
static int get_user_context(struct file *, struct hfi1_user_info *,
			    int, unsigned);
static int find_shared_ctxt(struct file *, const struct hfi1_user_info *);
static int allocate_ctxt(struct file *, struct hfi1_devdata *,
			 struct hfi1_user_info *);
static unsigned int poll_urgent(struct file *, struct poll_table_struct *);
static unsigned int poll_next(struct file *, struct poll_table_struct *);
static int user_event_ack(struct hfi1_ctxtdata *, int, unsigned long);
static int set_ctxt_pkey(struct hfi1_ctxtdata *, unsigned, u16);
static int manage_rcvq(struct hfi1_ctxtdata *, unsigned, int);
static int vma_fault(struct vm_area_struct *, struct vm_fault *);
static int exp_tid_setup(struct file *, struct hfi1_tid_info *);
static int exp_tid_free(struct file *, struct hfi1_tid_info *);
static void unlock_exp_tids(struct hfi1_ctxtdata *);

static const struct file_operations hfi1_file_ops = {
	.owner = THIS_MODULE,
	.write = hfi1_file_write,
	.write_iter = hfi1_write_iter,
	.open = hfi1_file_open,
	.release = hfi1_file_close,
	.poll = hfi1_poll,
	.mmap = hfi1_file_mmap,
	.llseek = noop_llseek,
};

static struct vm_operations_struct vm_ops = {
	.fault = vma_fault,
};

/*
 * Types of memories mapped into user processes' space
 */
enum mmap_types {
	PIO_BUFS = 1,
	PIO_BUFS_SOP,
	PIO_CRED,
	RCV_HDRQ,
	RCV_EGRBUF,
	UREGS,
	EVENTS,
	STATUS,
	RTAIL,
	SUBCTXT_UREGS,
	SUBCTXT_RCV_HDRQ,
	SUBCTXT_EGRBUF,
	SDMA_COMP
};

/*
 * Masks and offsets defining the mmap tokens
 */
#define HFI1_MMAP_OFFSET_MASK   0xfffULL
#define HFI1_MMAP_OFFSET_SHIFT  0
#define HFI1_MMAP_SUBCTXT_MASK  0xfULL
#define HFI1_MMAP_SUBCTXT_SHIFT 12
#define HFI1_MMAP_CTXT_MASK     0xffULL
#define HFI1_MMAP_CTXT_SHIFT    16
#define HFI1_MMAP_TYPE_MASK     0xfULL
#define HFI1_MMAP_TYPE_SHIFT    24
#define HFI1_MMAP_MAGIC_MASK    0xffffffffULL
#define HFI1_MMAP_MAGIC_SHIFT   32

#define HFI1_MMAP_MAGIC         0xdabbad00

#define HFI1_MMAP_TOKEN_SET(field, val)	\
	(((val) & HFI1_MMAP_##field##_MASK) << HFI1_MMAP_##field##_SHIFT)
#define HFI1_MMAP_TOKEN_GET(field, token) \
	(((token) >> HFI1_MMAP_##field##_SHIFT) & HFI1_MMAP_##field##_MASK)
#define HFI1_MMAP_TOKEN(type, ctxt, subctxt, addr)   \
	(HFI1_MMAP_TOKEN_SET(MAGIC, HFI1_MMAP_MAGIC) | \
	HFI1_MMAP_TOKEN_SET(TYPE, type) | \
	HFI1_MMAP_TOKEN_SET(CTXT, ctxt) | \
	HFI1_MMAP_TOKEN_SET(SUBCTXT, subctxt) | \
	HFI1_MMAP_TOKEN_SET(OFFSET, (offset_in_page(addr))))

#define EXP_TID_SET(field, value)			\
	(((value) & EXP_TID_TID##field##_MASK) <<	\
	 EXP_TID_TID##field##_SHIFT)
#define EXP_TID_CLEAR(tid, field) {					\
		(tid) &= ~(EXP_TID_TID##field##_MASK <<			\
			   EXP_TID_TID##field##_SHIFT);			\
			}
#define EXP_TID_RESET(tid, field, value) do {				\
		EXP_TID_CLEAR(tid, field);				\
		(tid) |= EXP_TID_SET(field, value);			\
	} while (0)

#define dbg(fmt, ...)				\
	pr_info(fmt, ##__VA_ARGS__)


static inline int is_valid_mmap(u64 token)
{
	return (HFI1_MMAP_TOKEN_GET(MAGIC, token) == HFI1_MMAP_MAGIC);
}

static int hfi1_file_open(struct inode *inode, struct file *fp)
{
	/* The real work is performed later in assign_ctxt() */
	fp->private_data = kzalloc(sizeof(struct hfi1_filedata), GFP_KERNEL);
	if (fp->private_data) /* no cpu affinity by default */
		((struct hfi1_filedata *)fp->private_data)->rec_cpu_num = -1;
	return fp->private_data ? 0 : -ENOMEM;
}

static ssize_t hfi1_file_write(struct file *fp, const char __user *data,
			       size_t count, loff_t *offset)
{
	const struct hfi1_cmd __user *ucmd;
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
	struct hfi1_cmd cmd;
	struct hfi1_user_info uinfo;
	struct hfi1_tid_info tinfo;
	ssize_t consumed = 0, copy = 0, ret = 0;
	void *dest = NULL;
	__u64 user_val = 0;
	int uctxt_required = 1;
	int must_be_root = 0;

	if (count < sizeof(cmd)) {
		ret = -EINVAL;
		goto bail;
	}

	ucmd = (const struct hfi1_cmd __user *)data;
	if (copy_from_user(&cmd, ucmd, sizeof(cmd))) {
		ret = -EFAULT;
		goto bail;
	}

	consumed = sizeof(cmd);

	switch (cmd.type) {
	case HFI1_CMD_ASSIGN_CTXT:
		uctxt_required = 0;	/* assigned user context not required */
		copy = sizeof(uinfo);
		dest = &uinfo;
		break;
	case HFI1_CMD_SDMA_STATUS_UPD:
	case HFI1_CMD_CREDIT_UPD:
		copy = 0;
		break;
	case HFI1_CMD_TID_UPDATE:
	case HFI1_CMD_TID_FREE:
		copy = sizeof(tinfo);
		dest = &tinfo;
		break;
	case HFI1_CMD_USER_INFO:
	case HFI1_CMD_RECV_CTRL:
	case HFI1_CMD_POLL_TYPE:
	case HFI1_CMD_ACK_EVENT:
	case HFI1_CMD_CTXT_INFO:
	case HFI1_CMD_SET_PKEY:
	case HFI1_CMD_CTXT_RESET:
		copy = 0;
		user_val = cmd.addr;
		break;
	case HFI1_CMD_EP_INFO:
	case HFI1_CMD_EP_ERASE_CHIP:
	case HFI1_CMD_EP_ERASE_P0:
	case HFI1_CMD_EP_ERASE_P1:
	case HFI1_CMD_EP_READ_P0:
	case HFI1_CMD_EP_READ_P1:
	case HFI1_CMD_EP_WRITE_P0:
	case HFI1_CMD_EP_WRITE_P1:
		uctxt_required = 0;	/* assigned user context not required */
		must_be_root = 1;	/* validate user */
		copy = 0;
		break;
	default:
		ret = -EINVAL;
		goto bail;
	}

	/* If the command comes with user data, copy it. */
	if (copy) {
		if (copy_from_user(dest, (void __user *)cmd.addr, copy)) {
			ret = -EFAULT;
			goto bail;
		}
		consumed += copy;
	}

	/*
	 * Make sure there is a uctxt when needed.
	 */
	if (uctxt_required && !uctxt) {
		ret = -EINVAL;
		goto bail;
	}

	/* only root can do these operations */
	if (must_be_root && !capable(CAP_SYS_ADMIN)) {
		ret = -EPERM;
		goto bail;
	}

	switch (cmd.type) {
	case HFI1_CMD_ASSIGN_CTXT:
		ret = assign_ctxt(fp, &uinfo);
		if (ret < 0)
			goto bail;
		ret = setup_ctxt(fp);
		if (ret)
			goto bail;
		ret = user_init(fp);
		break;
	case HFI1_CMD_CTXT_INFO:
		ret = get_ctxt_info(fp, (void __user *)(unsigned long)
				    user_val, cmd.len);
		break;
	case HFI1_CMD_USER_INFO:
		ret = get_base_info(fp, (void __user *)(unsigned long)
				    user_val, cmd.len);
		break;
	case HFI1_CMD_SDMA_STATUS_UPD:
		break;
	case HFI1_CMD_CREDIT_UPD:
		if (uctxt && uctxt->sc)
			sc_return_credits(uctxt->sc);
		break;
	case HFI1_CMD_TID_UPDATE:
		ret = exp_tid_setup(fp, &tinfo);
		if (!ret) {
			unsigned long addr;
			/*
			 * Copy the number of tidlist entries we used
			 * and the length of the buffer we registered.
			 * These fields are adjacent in the structure so
			 * we can copy them at the same time.
			 */
			addr = (unsigned long)cmd.addr +
				offsetof(struct hfi1_tid_info, tidcnt);
			if (copy_to_user((void __user *)addr, &tinfo.tidcnt,
					 sizeof(tinfo.tidcnt) +
					 sizeof(tinfo.length)))
				ret = -EFAULT;
		}
		break;
	case HFI1_CMD_TID_FREE:
		ret = exp_tid_free(fp, &tinfo);
		break;
	case HFI1_CMD_RECV_CTRL:
		ret = manage_rcvq(uctxt, subctxt_fp(fp), (int)user_val);
		break;
	case HFI1_CMD_POLL_TYPE:
		uctxt->poll_type = (typeof(uctxt->poll_type))user_val;
		break;
	case HFI1_CMD_ACK_EVENT:
		ret = user_event_ack(uctxt, subctxt_fp(fp), user_val);
		break;
	case HFI1_CMD_SET_PKEY:
		if (HFI1_CAP_IS_USET(PKEY_CHECK))
			ret = set_ctxt_pkey(uctxt, subctxt_fp(fp), user_val);
		else
			ret = -EPERM;
		break;
	case HFI1_CMD_CTXT_RESET: {
		struct send_context *sc;
		struct hfi1_devdata *dd;

		if (!uctxt || !uctxt->dd || !uctxt->sc) {
			ret = -EINVAL;
			break;
		}
		/*
		 * There is no protection here. User level has to
		 * guarantee that no one will be writing to the send
		 * context while it is being re-initialized.
		 * If user level breaks that guarantee, it will break
		 * it's own context and no one else's.
		 */
		dd = uctxt->dd;
		sc = uctxt->sc;
		/*
		 * Wait until the interrupt handler has marked the
		 * context as halted or frozen. Report error if we time
		 * out.
		 */
		wait_event_interruptible_timeout(
			sc->halt_wait, (sc->flags & SCF_HALTED),
			msecs_to_jiffies(SEND_CTXT_HALT_TIMEOUT));
		if (!(sc->flags & SCF_HALTED)) {
			ret = -ENOLCK;
			break;
		}
		/*
		 * If the send context was halted due to a Freeze,
		 * wait until the device has been "unfrozen" before
		 * resetting the context.
		 */
		if (sc->flags & SCF_FROZEN) {
			wait_event_interruptible_timeout(
				dd->event_queue,
				!(ACCESS_ONCE(dd->flags) & HFI1_FROZEN),
				msecs_to_jiffies(SEND_CTXT_HALT_TIMEOUT));
			if (dd->flags & HFI1_FROZEN) {
				ret = -ENOLCK;
				break;
			}
			if (dd->flags & HFI1_FORCED_FREEZE) {
				/* Don't allow context reset if we are into
				 * forced freeze */
				ret = -ENODEV;
				break;
			}
			sc_disable(sc);
			ret = sc_enable(sc);
			hfi1_rcvctrl(dd, HFI1_RCVCTRL_CTXT_ENB,
				     uctxt->ctxt);
		} else
			ret = sc_restart(sc);
		if (!ret)
			sc_return_credits(sc);
		break;
	}
	case HFI1_CMD_EP_INFO:
	case HFI1_CMD_EP_ERASE_CHIP:
	case HFI1_CMD_EP_ERASE_P0:
	case HFI1_CMD_EP_ERASE_P1:
	case HFI1_CMD_EP_READ_P0:
	case HFI1_CMD_EP_READ_P1:
	case HFI1_CMD_EP_WRITE_P0:
	case HFI1_CMD_EP_WRITE_P1:
		ret = handle_eprom_command(&cmd);
		break;
	}

	if (ret >= 0)
		ret = consumed;
bail:
	return ret;
}

static ssize_t hfi1_write_iter(struct kiocb *kiocb, struct iov_iter *from)
{
	struct hfi1_user_sdma_pkt_q *pq;
	struct hfi1_user_sdma_comp_q *cq;
	int ret = 0, done = 0, reqs = 0;
	unsigned long dim = from->nr_segs;

	if (!user_sdma_comp_fp(kiocb->ki_filp) ||
	    !user_sdma_pkt_fp(kiocb->ki_filp)) {
		ret = -EIO;
		goto done;
	}

	if (!iter_is_iovec(from) || !dim) {
		ret = -EINVAL;
		goto done;
	}

	hfi1_cdbg(SDMA, "SDMA request from %u:%u (%lu)",
		  ctxt_fp(kiocb->ki_filp)->ctxt, subctxt_fp(kiocb->ki_filp),
		  dim);
	pq = user_sdma_pkt_fp(kiocb->ki_filp);
	cq = user_sdma_comp_fp(kiocb->ki_filp);

	if (atomic_read(&pq->n_reqs) == pq->n_max_reqs) {
		ret = -ENOSPC;
		goto done;
	}

	while (dim) {
		unsigned long count = 0;

		ret = hfi1_user_sdma_process_request(
			kiocb->ki_filp,	(struct iovec *)(from->iov + done),
			dim, &count);
		if (ret)
			goto done;
		dim -= count;
		done += count;
		reqs++;
	}
done:
	return ret ? ret : reqs;
}

static int hfi1_file_mmap(struct file *fp, struct vm_area_struct *vma)
{
	struct hfi1_ctxtdata *uctxt;
	struct hfi1_devdata *dd;
	unsigned long flags, pfn;
	u64 token = vma->vm_pgoff << PAGE_SHIFT,
		memaddr = 0;
	u8 subctxt, mapio = 0, vmf = 0, type;
	ssize_t memlen = 0;
	int ret = 0;
	u16 ctxt;

	uctxt = ctxt_fp(fp);
	if (!is_valid_mmap(token) || !uctxt ||
	    !(vma->vm_flags & VM_SHARED)) {
		ret = -EINVAL;
		goto done;
	}
	dd = uctxt->dd;
	ctxt = HFI1_MMAP_TOKEN_GET(CTXT, token);
	subctxt = HFI1_MMAP_TOKEN_GET(SUBCTXT, token);
	type = HFI1_MMAP_TOKEN_GET(TYPE, token);
	if (ctxt != uctxt->ctxt || subctxt != subctxt_fp(fp)) {
		ret = -EINVAL;
		goto done;
	}

	flags = vma->vm_flags;

	switch (type) {
	case PIO_BUFS:
	case PIO_BUFS_SOP:
		memaddr = ((dd->physaddr + TXE_PIO_SEND) +
				/* chip pio base */
			   (uctxt->sc->hw_context * BIT(16))) +
				/* 64K PIO space / ctxt */
			(type == PIO_BUFS_SOP ?
				(TXE_PIO_SIZE / 2) : 0); /* sop? */
		/*
		 * Map only the amount allocated to the context, not the
		 * entire available context's PIO space.
		 */
		memlen = ALIGN(uctxt->sc->credits * PIO_BLOCK_SIZE,
			       PAGE_SIZE);
		flags &= ~VM_MAYREAD;
		flags |= VM_DONTCOPY | VM_DONTEXPAND;
		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
		mapio = 1;
		break;
	case PIO_CRED:
		if (flags & VM_WRITE) {
			ret = -EPERM;
			goto done;
		}
		/*
		 * The credit return location for this context could be on the
		 * second or third page allocated for credit returns (if number
		 * of enabled contexts > 64 and 128 respectively).
		 */
		memaddr = dd->cr_base[uctxt->numa_id].pa +
			(((u64)uctxt->sc->hw_free -
			  (u64)dd->cr_base[uctxt->numa_id].va) & PAGE_MASK);
		memlen = PAGE_SIZE;
		flags &= ~VM_MAYWRITE;
		flags |= VM_DONTCOPY | VM_DONTEXPAND;
		/*
		 * The driver has already allocated memory for credit
		 * returns and programmed it into the chip. Has that
		 * memory been flagged as non-cached?
		 */
		/* vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); */
		mapio = 1;
		break;
	case RCV_HDRQ:
		memaddr = uctxt->rcvhdrq_phys;
		memlen = uctxt->rcvhdrq_size;
		break;
	case RCV_EGRBUF: {
		unsigned long addr;
		int i;
		/*
		 * The RcvEgr buffer need to be handled differently
		 * as multiple non-contiguous pages need to be mapped
		 * into the user process.
		 */
		memlen = uctxt->egrbufs.size;
		if ((vma->vm_end - vma->vm_start) != memlen) {
			dd_dev_err(dd, "Eager buffer map size invalid (%lu != %lu)\n",
				   (vma->vm_end - vma->vm_start), memlen);
			ret = -EINVAL;
			goto done;
		}
		if (vma->vm_flags & VM_WRITE) {
			ret = -EPERM;
			goto done;
		}
		vma->vm_flags &= ~VM_MAYWRITE;
		addr = vma->vm_start;
		for (i = 0 ; i < uctxt->egrbufs.numbufs; i++) {
			ret = remap_pfn_range(
				vma, addr,
				uctxt->egrbufs.buffers[i].phys >> PAGE_SHIFT,
				uctxt->egrbufs.buffers[i].len,
				vma->vm_page_prot);
			if (ret < 0)
				goto done;
			addr += uctxt->egrbufs.buffers[i].len;
		}
		ret = 0;
		goto done;
	}
	case UREGS:
		/*
		 * Map only the page that contains this context's user
		 * registers.
		 */
		memaddr = (unsigned long)
			(dd->physaddr + RXE_PER_CONTEXT_USER)
			+ (uctxt->ctxt * RXE_PER_CONTEXT_SIZE);
		/*
		 * TidFlow table is on the same page as the rest of the
		 * user registers.
		 */
		memlen = PAGE_SIZE;
		flags |= VM_DONTCOPY | VM_DONTEXPAND;
		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
		mapio = 1;
		break;
	case EVENTS:
		/*
		 * Use the page where this context's flags are. User level
		 * knows where it's own bitmap is within the page.
		 */
		memaddr = ((unsigned long)dd->events +
			   ((uctxt->ctxt - dd->first_user_ctxt) *
			    HFI1_MAX_SHARED_CTXTS)) & PAGE_MASK;
		memlen = PAGE_SIZE;
		/*
		 * v3.7 removes VM_RESERVED but the effect is kept by
		 * using VM_IO.
		 */
		flags |= VM_IO | VM_DONTEXPAND;
		vmf = 1;
		break;
	case STATUS:
		memaddr = kvirt_to_phys((void *)dd->status);
		memlen = PAGE_SIZE;
		flags |= VM_IO | VM_DONTEXPAND;
		break;
	case RTAIL:
		if (!HFI1_CAP_IS_USET(DMA_RTAIL)) {
			/*
			 * If the memory allocation failed, the context alloc
			 * also would have failed, so we would never get here
			 */
			ret = -EINVAL;
			goto done;
		}
		if (flags & VM_WRITE) {
			ret = -EPERM;
			goto done;
		}
		memaddr = uctxt->rcvhdrqtailaddr_phys;
		memlen = PAGE_SIZE;
		flags &= ~VM_MAYWRITE;
		break;
	case SUBCTXT_UREGS:
		memaddr = (u64)uctxt->subctxt_uregbase;
		memlen = PAGE_SIZE;
		flags |= VM_IO | VM_DONTEXPAND;
		vmf = 1;
		break;
	case SUBCTXT_RCV_HDRQ:
		memaddr = (u64)uctxt->subctxt_rcvhdr_base;
		memlen = uctxt->rcvhdrq_size * uctxt->subctxt_cnt;
		flags |= VM_IO | VM_DONTEXPAND;
		vmf = 1;
		break;
	case SUBCTXT_EGRBUF:
		memaddr = (u64)uctxt->subctxt_rcvegrbuf;
		memlen = uctxt->egrbufs.size * uctxt->subctxt_cnt;
		flags |= VM_IO | VM_DONTEXPAND;
		flags &= ~VM_MAYWRITE;
		vmf = 1;
		break;
	case SDMA_COMP: {
		struct hfi1_user_sdma_comp_q *cq;

		if (!user_sdma_comp_fp(fp)) {
			ret = -EFAULT;
			goto done;
		}
		cq = user_sdma_comp_fp(fp);
		memaddr = (u64)cq->comps;
		memlen = ALIGN(sizeof(*cq->comps) * cq->nentries, PAGE_SIZE);
		flags |= VM_IO | VM_DONTEXPAND;
		vmf = 1;
		break;
	}
	default:
		ret = -EINVAL;
		break;
	}

	if ((vma->vm_end - vma->vm_start) != memlen) {
		hfi1_cdbg(PROC, "%u:%u Memory size mismatch %lu:%lu",
			  uctxt->ctxt, subctxt_fp(fp),
			  (vma->vm_end - vma->vm_start), memlen);
		ret = -EINVAL;
		goto done;
	}

	vma->vm_flags = flags;
	dd_dev_info(dd,
		    "%s: %u:%u type:%u io/vf:%d/%d, addr:0x%llx, len:%lu(%lu), flags:0x%lx\n",
		    __func__, ctxt, subctxt, type, mapio, vmf, memaddr, memlen,
		    vma->vm_end - vma->vm_start, vma->vm_flags);
	pfn = (unsigned long)(memaddr >> PAGE_SHIFT);
	if (vmf) {
		vma->vm_pgoff = pfn;
		vma->vm_ops = &vm_ops;
		ret = 0;
	} else if (mapio) {
		ret = io_remap_pfn_range(vma, vma->vm_start, pfn, memlen,
					 vma->vm_page_prot);
	} else {
		ret = remap_pfn_range(vma, vma->vm_start, pfn, memlen,
				      vma->vm_page_prot);
	}
done:
	return ret;
}

/*
 * Local (non-chip) user memory is not mapped right away but as it is
 * accessed by the user-level code.
 */
static int vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
	struct page *page;

	page = vmalloc_to_page((void *)(vmf->pgoff << PAGE_SHIFT));
	if (!page)
		return VM_FAULT_SIGBUS;

	get_page(page);
	vmf->page = page;

	return 0;
}

static unsigned int hfi1_poll(struct file *fp, struct poll_table_struct *pt)
{
	struct hfi1_ctxtdata *uctxt;
	unsigned pollflag;

	uctxt = ctxt_fp(fp);
	if (!uctxt)
		pollflag = POLLERR;
	else if (uctxt->poll_type == HFI1_POLL_TYPE_URGENT)
		pollflag = poll_urgent(fp, pt);
	else  if (uctxt->poll_type == HFI1_POLL_TYPE_ANYRCV)
		pollflag = poll_next(fp, pt);
	else /* invalid */
		pollflag = POLLERR;

	return pollflag;
}

static int hfi1_file_close(struct inode *inode, struct file *fp)
{
	struct hfi1_filedata *fdata = fp->private_data;
	struct hfi1_ctxtdata *uctxt = fdata->uctxt;
	struct hfi1_devdata *dd;
	unsigned long flags, *ev;

	fp->private_data = NULL;

	if (!uctxt)
		goto done;

	hfi1_cdbg(PROC, "freeing ctxt %u:%u", uctxt->ctxt, fdata->subctxt);
	dd = uctxt->dd;
	mutex_lock(&hfi1_mutex);

	flush_wc();
	/* drain user sdma queue */
	if (fdata->pq)
		hfi1_user_sdma_free_queues(fdata);

	/*
	 * Clear any left over, unhandled events so the next process that
	 * gets this context doesn't get confused.
	 */
	ev = dd->events + ((uctxt->ctxt - dd->first_user_ctxt) *
			   HFI1_MAX_SHARED_CTXTS) + fdata->subctxt;
	*ev = 0;

	if (--uctxt->cnt) {
		uctxt->active_slaves &= ~(1 << fdata->subctxt);
		uctxt->subpid[fdata->subctxt] = 0;
		mutex_unlock(&hfi1_mutex);
		goto done;
	}

	spin_lock_irqsave(&dd->uctxt_lock, flags);
	/*
	 * Disable receive context and interrupt available, reset all
	 * RcvCtxtCtrl bits to default values.
	 */
	hfi1_rcvctrl(dd, HFI1_RCVCTRL_CTXT_DIS |
		     HFI1_RCVCTRL_TIDFLOW_DIS |
		     HFI1_RCVCTRL_INTRAVAIL_DIS |
		     HFI1_RCVCTRL_ONE_PKT_EGR_DIS |
		     HFI1_RCVCTRL_NO_RHQ_DROP_DIS |
		     HFI1_RCVCTRL_NO_EGR_DROP_DIS, uctxt->ctxt);
	/* Clear the context's J_KEY */
	hfi1_clear_ctxt_jkey(dd, uctxt->ctxt);
	/*
	 * Reset context integrity checks to default.
	 * (writes to CSRs probably belong in chip.c)
	 */
	write_kctxt_csr(dd, uctxt->sc->hw_context, SEND_CTXT_CHECK_ENABLE,
			hfi1_pkt_default_send_ctxt_mask(dd, uctxt->sc->type));
	sc_disable(uctxt->sc);
	uctxt->pid = 0;
	spin_unlock_irqrestore(&dd->uctxt_lock, flags);

	dd->rcd[uctxt->ctxt] = NULL;
	uctxt->rcvwait_to = 0;
	uctxt->piowait_to = 0;
	uctxt->rcvnowait = 0;
	uctxt->pionowait = 0;
	uctxt->event_flags = 0;

	hfi1_clear_tids(uctxt);
	hfi1_clear_ctxt_pkey(dd, uctxt->ctxt);

	if (uctxt->tid_pg_list)
		unlock_exp_tids(uctxt);

	hfi1_stats.sps_ctxts--;
	dd->freectxts++;
	mutex_unlock(&hfi1_mutex);
	hfi1_free_ctxtdata(dd, uctxt);
done:
	kfree(fdata);
	return 0;
}

/*
 * Convert kernel *virtual* addresses to physical addresses.
 * This is used to vmalloc'ed addresses.
 */
static u64 kvirt_to_phys(void *addr)
{
	struct page *page;
	u64 paddr = 0;

	page = vmalloc_to_page(addr);
	if (page)
		paddr = page_to_pfn(page) << PAGE_SHIFT;

	return paddr;
}

static int assign_ctxt(struct file *fp, struct hfi1_user_info *uinfo)
{
	int i_minor, ret = 0;
	unsigned swmajor, swminor, alg = HFI1_ALG_ACROSS;

	swmajor = uinfo->userversion >> 16;
	if (swmajor != HFI1_USER_SWMAJOR) {
		ret = -ENODEV;
		goto done;
	}

	swminor = uinfo->userversion & 0xffff;

	if (uinfo->hfi1_alg < HFI1_ALG_COUNT)
		alg = uinfo->hfi1_alg;

	mutex_lock(&hfi1_mutex);
	/* First, lets check if we need to setup a shared context? */
	if (uinfo->subctxt_cnt)
		ret = find_shared_ctxt(fp, uinfo);

	/*
	 * We execute the following block if we couldn't find a
	 * shared context or if context sharing is not required.
	 */
	if (!ret) {
		i_minor = iminor(file_inode(fp)) - HFI1_USER_MINOR_BASE;
		ret = get_user_context(fp, uinfo, i_minor - 1, alg);
	}
	mutex_unlock(&hfi1_mutex);
done:
	return ret;
}

static int get_user_context(struct file *fp, struct hfi1_user_info *uinfo,
			    int devno, unsigned alg)
{
	struct hfi1_devdata *dd = NULL;
	int ret = 0, devmax, npresent, nup, dev;

	devmax = hfi1_count_units(&npresent, &nup);
	if (!npresent) {
		ret = -ENXIO;
		goto done;
	}
	if (!nup) {
		ret = -ENETDOWN;
		goto done;
	}
	if (devno >= 0) {
		dd = hfi1_lookup(devno);
		if (!dd)
			ret = -ENODEV;
		else if (!dd->freectxts)
			ret = -EBUSY;
	} else {
		struct hfi1_devdata *pdd;

		if (alg == HFI1_ALG_ACROSS) {
			unsigned free = 0U;

			for (dev = 0; dev < devmax; dev++) {
				pdd = hfi1_lookup(dev);
				if (pdd && pdd->freectxts &&
				    pdd->freectxts > free) {
					dd = pdd;
					free = pdd->freectxts;
				}
			}
		} else {
			for (dev = 0; dev < devmax; dev++) {
				pdd = hfi1_lookup(dev);
				if (pdd && pdd->freectxts) {
					dd = pdd;
					break;
				}
			}
		}
		if (!dd)
			ret = -EBUSY;
	}
done:
	return ret ? ret : allocate_ctxt(fp, dd, uinfo);
}

static int find_shared_ctxt(struct file *fp,
			    const struct hfi1_user_info *uinfo)
{
	int devmax, ndev, i;
	int ret = 0;

	devmax = hfi1_count_units(NULL, NULL);

	for (ndev = 0; ndev < devmax; ndev++) {
		struct hfi1_devdata *dd = hfi1_lookup(ndev);

		/* device portion of usable() */
		if (!(dd && (dd->flags & HFI1_PRESENT) && dd->kregbase))
			continue;
		for (i = dd->first_user_ctxt; i < dd->num_rcv_contexts; i++) {
			struct hfi1_ctxtdata *uctxt = dd->rcd[i];

			/* Skip ctxts which are not yet open */
			if (!uctxt || !uctxt->cnt)
				continue;
			/* Skip ctxt if it doesn't match the requested one */
			if (memcmp(uctxt->uuid, uinfo->uuid,
				   sizeof(uctxt->uuid)) ||
			    uctxt->subctxt_id != uinfo->subctxt_id ||
			    uctxt->subctxt_cnt != uinfo->subctxt_cnt)
				continue;

			/* Verify the sharing process matches the master */
			if (uctxt->userversion != uinfo->userversion ||
			    uctxt->cnt >= uctxt->subctxt_cnt) {
				ret = -EINVAL;
				goto done;
			}
			ctxt_fp(fp) = uctxt;
			subctxt_fp(fp) = uctxt->cnt++;
			uctxt->subpid[subctxt_fp(fp)] = current->pid;
			uctxt->active_slaves |= 1 << subctxt_fp(fp);
			ret = 1;
			goto done;
		}
	}

done:
	return ret;
}

static int allocate_ctxt(struct file *fp, struct hfi1_devdata *dd,
			 struct hfi1_user_info *uinfo)
{
	struct hfi1_ctxtdata *uctxt;
	unsigned ctxt;
	int ret;

	if (dd->flags & HFI1_FROZEN) {
		/*
		 * Pick an error that is unique from all other errors
		 * that are returned so the user process knows that
		 * it tried to allocate while the SPC was frozen.  It
		 * it should be able to retry with success in a short
		 * while.
		 */
		return -EIO;
	}

	for (ctxt = dd->first_user_ctxt; ctxt < dd->num_rcv_contexts; ctxt++)
		if (!dd->rcd[ctxt])
			break;

	if (ctxt == dd->num_rcv_contexts)
		return -EBUSY;

	uctxt = hfi1_create_ctxtdata(dd->pport, ctxt);
	if (!uctxt) {
		dd_dev_err(dd,
			   "Unable to allocate ctxtdata memory, failing open\n");
		return -ENOMEM;
	}
	/*
	 * Allocate and enable a PIO send context.
	 */
	uctxt->sc = sc_alloc(dd, SC_USER, uctxt->rcvhdrqentsize,
			     uctxt->numa_id);
	if (!uctxt->sc)
		return -ENOMEM;

	dbg("allocated send context %u(%u)\n", uctxt->sc->sw_index,
		uctxt->sc->hw_context);
	ret = sc_enable(uctxt->sc);
	if (ret)
		return ret;
	/*
	 * Setup shared context resources if the user-level has requested
	 * shared contexts and this is the 'master' process.
	 * This has to be done here so the rest of the sub-contexts find the
	 * proper master.
	 */
	if (uinfo->subctxt_cnt && !subctxt_fp(fp)) {
		ret = init_subctxts(uctxt, uinfo);
		/*
		 * On error, we don't need to disable and de-allocate the
		 * send context because it will be done during file close
		 */
		if (ret)
			return ret;
	}
	uctxt->userversion = uinfo->userversion;
	uctxt->pid = current->pid;
	uctxt->flags = HFI1_CAP_UGET(MASK);
	init_waitqueue_head(&uctxt->wait);
	strlcpy(uctxt->comm, current->comm, sizeof(uctxt->comm));
	memcpy(uctxt->uuid, uinfo->uuid, sizeof(uctxt->uuid));
	uctxt->jkey = generate_jkey(current_uid());
	INIT_LIST_HEAD(&uctxt->sdma_queues);
	spin_lock_init(&uctxt->sdma_qlock);
	hfi1_stats.sps_ctxts++;
	dd->freectxts--;
	ctxt_fp(fp) = uctxt;

	return 0;
}

static int init_subctxts(struct hfi1_ctxtdata *uctxt,
			 const struct hfi1_user_info *uinfo)
{
	int ret = 0;
	unsigned num_subctxts;

	num_subctxts = uinfo->subctxt_cnt;
	if (num_subctxts > HFI1_MAX_SHARED_CTXTS) {
		ret = -EINVAL;
		goto bail;
	}

	uctxt->subctxt_cnt = uinfo->subctxt_cnt;
	uctxt->subctxt_id = uinfo->subctxt_id;
	uctxt->active_slaves = 1;
	uctxt->redirect_seq_cnt = 1;
	set_bit(HFI1_CTXT_MASTER_UNINIT, &uctxt->event_flags);
bail:
	return ret;
}

static int setup_subctxt(struct hfi1_ctxtdata *uctxt)
{
	int ret = 0;
	unsigned num_subctxts = uctxt->subctxt_cnt;

	uctxt->subctxt_uregbase = vmalloc_user(PAGE_SIZE);
	if (!uctxt->subctxt_uregbase) {
		ret = -ENOMEM;
		goto bail;
	}
	/* We can take the size of the RcvHdr Queue from the master */
	uctxt->subctxt_rcvhdr_base = vmalloc_user(uctxt->rcvhdrq_size *
						  num_subctxts);
	if (!uctxt->subctxt_rcvhdr_base) {
		ret = -ENOMEM;
		goto bail_ureg;
	}

	uctxt->subctxt_rcvegrbuf = vmalloc_user(uctxt->egrbufs.size *
						num_subctxts);
	if (!uctxt->subctxt_rcvegrbuf) {
		ret = -ENOMEM;
		goto bail_rhdr;
	}
	goto bail;
bail_rhdr:
	vfree(uctxt->subctxt_rcvhdr_base);
bail_ureg:
	vfree(uctxt->subctxt_uregbase);
	uctxt->subctxt_uregbase = NULL;
bail:
	return ret;
}

static int user_init(struct file *fp)
{
	int ret;
	unsigned int rcvctrl_ops = 0;
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);

	/* make sure that the context has already been setup */
	if (!test_bit(HFI1_CTXT_SETUP_DONE, &uctxt->event_flags)) {
		ret = -EFAULT;
		goto done;
	}

	/*
	 * Subctxts don't need to initialize anything since master
	 * has done it.
	 */
	if (subctxt_fp(fp)) {
		ret = wait_event_interruptible(uctxt->wait,
			!test_bit(HFI1_CTXT_MASTER_UNINIT,
			&uctxt->event_flags));
		goto done;
	}

	/* initialize poll variables... */
	uctxt->urgent = 0;
	uctxt->urgent_poll = 0;

	/*
	 * Now enable the ctxt for receive.
	 * For chips that are set to DMA the tail register to memory
	 * when they change (and when the update bit transitions from
	 * 0 to 1.  So for those chips, we turn it off and then back on.
	 * This will (very briefly) affect any other open ctxts, but the
	 * duration is very short, and therefore isn't an issue.  We
	 * explicitly set the in-memory tail copy to 0 beforehand, so we
	 * don't have to wait to be sure the DMA update has happened
	 * (chip resets head/tail to 0 on transition to enable).
	 */
	if (uctxt->rcvhdrtail_kvaddr)
		clear_rcvhdrtail(uctxt);

	/* Setup J_KEY before enabling the context */
	hfi1_set_ctxt_jkey(uctxt->dd, uctxt->ctxt, uctxt->jkey);

	rcvctrl_ops = HFI1_RCVCTRL_CTXT_ENB;
	if (HFI1_CAP_KGET_MASK(uctxt->flags, HDRSUPP))
		rcvctrl_ops |= HFI1_RCVCTRL_TIDFLOW_ENB;
	/*
	 * Ignore the bit in the flags for now until proper
	 * support for multiple packet per rcv array entry is
	 * added.
	 */
	if (!HFI1_CAP_KGET_MASK(uctxt->flags, MULTI_PKT_EGR))
		rcvctrl_ops |= HFI1_RCVCTRL_ONE_PKT_EGR_ENB;
	if (HFI1_CAP_KGET_MASK(uctxt->flags, NODROP_EGR_FULL))
		rcvctrl_ops |= HFI1_RCVCTRL_NO_EGR_DROP_ENB;
	if (HFI1_CAP_KGET_MASK(uctxt->flags, NODROP_RHQ_FULL))
		rcvctrl_ops |= HFI1_RCVCTRL_NO_RHQ_DROP_ENB;
	if (HFI1_CAP_KGET_MASK(uctxt->flags, DMA_RTAIL))
		rcvctrl_ops |= HFI1_RCVCTRL_TAILUPD_ENB;
	hfi1_rcvctrl(uctxt->dd, rcvctrl_ops, uctxt->ctxt);

	/* Notify any waiting slaves */
	if (uctxt->subctxt_cnt) {
		clear_bit(HFI1_CTXT_MASTER_UNINIT, &uctxt->event_flags);
		wake_up(&uctxt->wait);
	}
	ret = 0;

done:
	return ret;
}

static int get_ctxt_info(struct file *fp, void __user *ubase, __u32 len)
{
	struct hfi1_ctxt_info cinfo;
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
	struct hfi1_filedata *fd = fp->private_data;
	int ret = 0;

	memset(&cinfo, 0, sizeof(cinfo));
	ret = hfi1_get_base_kinfo(uctxt, &cinfo);
	if (ret < 0)
		goto done;
	cinfo.num_active = hfi1_count_active_units();
	cinfo.unit = uctxt->dd->unit;
	cinfo.ctxt = uctxt->ctxt;
	cinfo.subctxt = subctxt_fp(fp);
	cinfo.rcvtids = roundup(uctxt->egrbufs.alloced,
				uctxt->dd->rcv_entries.group_size) +
		uctxt->expected_count;
	cinfo.credits = uctxt->sc->credits;
	cinfo.numa_node = uctxt->numa_id;
	cinfo.rec_cpu = fd->rec_cpu_num;
	cinfo.send_ctxt = uctxt->sc->hw_context;

	cinfo.egrtids = uctxt->egrbufs.alloced;
	cinfo.rcvhdrq_cnt = uctxt->rcvhdrq_cnt;
	cinfo.rcvhdrq_entsize = uctxt->rcvhdrqentsize << 2;
	cinfo.sdma_ring_size = user_sdma_comp_fp(fp)->nentries;
	cinfo.rcvegr_size = uctxt->egrbufs.rcvtid_size;

	trace_hfi1_ctxt_info(uctxt->dd, uctxt->ctxt, subctxt_fp(fp), cinfo);
	if (copy_to_user(ubase, &cinfo, sizeof(cinfo)))
		ret = -EFAULT;
done:
	return ret;
}

static int setup_ctxt(struct file *fp)
{
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
	struct hfi1_devdata *dd = uctxt->dd;
	int ret = 0;

	/*
	 * Context should be set up only once (including allocation and
	 * programming of eager buffers. This is done if context sharing
	 * is not requested or by the master process.
	 */
	if (!uctxt->subctxt_cnt || !subctxt_fp(fp)) {
		ret = hfi1_init_ctxt(uctxt->sc);
		if (ret)
			goto done;

		/* Now allocate the RcvHdr queue and eager buffers. */
		ret = hfi1_create_rcvhdrq(dd, uctxt);
		if (ret)
			goto done;
		ret = hfi1_setup_eagerbufs(uctxt);
		if (ret)
			goto done;
		if (uctxt->subctxt_cnt && !subctxt_fp(fp)) {
			ret = setup_subctxt(uctxt);
			if (ret)
				goto done;
		}
		/* Setup Expected Rcv memories */
		uctxt->tid_pg_list = vzalloc(uctxt->expected_count *
					     sizeof(struct page **));
		if (!uctxt->tid_pg_list) {
			ret = -ENOMEM;
			goto done;
		}
		uctxt->physshadow = vzalloc(uctxt->expected_count *
					    sizeof(*uctxt->physshadow));
		if (!uctxt->physshadow) {
			ret = -ENOMEM;
			goto done;
		}
		/* allocate expected TID map and initialize the cursor */
		atomic_set(&uctxt->tidcursor, 0);
		uctxt->numtidgroups = uctxt->expected_count /
			dd->rcv_entries.group_size;
		uctxt->tidmapcnt = uctxt->numtidgroups / BITS_PER_LONG +
			!!(uctxt->numtidgroups % BITS_PER_LONG);
		uctxt->tidusemap = kzalloc_node(uctxt->tidmapcnt *
						sizeof(*uctxt->tidusemap),
						GFP_KERNEL, uctxt->numa_id);
		if (!uctxt->tidusemap) {
			ret = -ENOMEM;
			goto done;
		}
		/*
		 * In case that the number of groups is not a multiple of
		 * 64 (the number of groups in a tidusemap element), mark
		 * the extra ones as used. This will effectively make them
		 * permanently used and should never be assigned. Otherwise,
		 * the code which checks how many free groups we have will
		 * get completely confused about the state of the bits.
		 */
		if (uctxt->numtidgroups % BITS_PER_LONG)
			uctxt->tidusemap[uctxt->tidmapcnt - 1] =
				~((1ULL << (uctxt->numtidgroups %
					    BITS_PER_LONG)) - 1);
		trace_hfi1_exp_tid_map(uctxt->ctxt, subctxt_fp(fp), 0,
				       uctxt->tidusemap, uctxt->tidmapcnt);
	}
	ret = hfi1_user_sdma_alloc_queues(uctxt, fp);
	if (ret)
		goto done;

	set_bit(HFI1_CTXT_SETUP_DONE, &uctxt->event_flags);
done:
	return ret;
}

static int get_base_info(struct file *fp, void __user *ubase, __u32 len)
{
	struct hfi1_base_info binfo;
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
	struct hfi1_devdata *dd = uctxt->dd;
	ssize_t sz;
	unsigned offset;
	int ret = 0;

	trace_hfi1_uctxtdata(uctxt->dd, uctxt);

	memset(&binfo, 0, sizeof(binfo));
	binfo.hw_version = dd->revision;
	binfo.sw_version = HFI1_KERN_SWVERSION;
	binfo.bthqp = kdeth_qp;
	binfo.jkey = uctxt->jkey;
	/*
	 * If more than 64 contexts are enabled the allocated credit
	 * return will span two or three contiguous pages. Since we only
	 * map the page containing the context's credit return address,
	 * we need to calculate the offset in the proper page.
	 */
	offset = ((u64)uctxt->sc->hw_free -
		  (u64)dd->cr_base[uctxt->numa_id].va) % PAGE_SIZE;
	binfo.sc_credits_addr = HFI1_MMAP_TOKEN(PIO_CRED, uctxt->ctxt,
					       subctxt_fp(fp), offset);
	binfo.pio_bufbase = HFI1_MMAP_TOKEN(PIO_BUFS, uctxt->ctxt,
					    subctxt_fp(fp),
					    uctxt->sc->base_addr);
	binfo.pio_bufbase_sop = HFI1_MMAP_TOKEN(PIO_BUFS_SOP,
						uctxt->ctxt,
						subctxt_fp(fp),
						uctxt->sc->base_addr);
	binfo.rcvhdr_bufbase = HFI1_MMAP_TOKEN(RCV_HDRQ, uctxt->ctxt,
					       subctxt_fp(fp),
					       uctxt->rcvhdrq);
	binfo.rcvegr_bufbase = HFI1_MMAP_TOKEN(RCV_EGRBUF, uctxt->ctxt,
					       subctxt_fp(fp),
					       uctxt->egrbufs.rcvtids[0].phys);
	binfo.sdma_comp_bufbase = HFI1_MMAP_TOKEN(SDMA_COMP, uctxt->ctxt,
						 subctxt_fp(fp), 0);
	/*
	 * user regs are at
	 * (RXE_PER_CONTEXT_USER + (ctxt * RXE_PER_CONTEXT_SIZE))
	 */
	binfo.user_regbase = HFI1_MMAP_TOKEN(UREGS, uctxt->ctxt,
					    subctxt_fp(fp), 0);
	offset = offset_in_page((((uctxt->ctxt - dd->first_user_ctxt) *
		    HFI1_MAX_SHARED_CTXTS) + subctxt_fp(fp)) *
		  sizeof(*dd->events));
	binfo.events_bufbase = HFI1_MMAP_TOKEN(EVENTS, uctxt->ctxt,
					      subctxt_fp(fp),
					      offset);
	binfo.status_bufbase = HFI1_MMAP_TOKEN(STATUS, uctxt->ctxt,
					      subctxt_fp(fp),
					      dd->status);
	if (HFI1_CAP_IS_USET(DMA_RTAIL))
		binfo.rcvhdrtail_base = HFI1_MMAP_TOKEN(RTAIL, uctxt->ctxt,
						       subctxt_fp(fp), 0);
	if (uctxt->subctxt_cnt) {
		binfo.subctxt_uregbase = HFI1_MMAP_TOKEN(SUBCTXT_UREGS,
							uctxt->ctxt,
							subctxt_fp(fp), 0);
		binfo.subctxt_rcvhdrbuf = HFI1_MMAP_TOKEN(SUBCTXT_RCV_HDRQ,
							 uctxt->ctxt,
							 subctxt_fp(fp), 0);
		binfo.subctxt_rcvegrbuf = HFI1_MMAP_TOKEN(SUBCTXT_EGRBUF,
							 uctxt->ctxt,
							 subctxt_fp(fp), 0);
	}
	sz = (len < sizeof(binfo)) ? len : sizeof(binfo);
	if (copy_to_user(ubase, &binfo, sz))
		ret = -EFAULT;
	return ret;
}

static unsigned int poll_urgent(struct file *fp,
				struct poll_table_struct *pt)
{
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
	struct hfi1_devdata *dd = uctxt->dd;
	unsigned pollflag;

	poll_wait(fp, &uctxt->wait, pt);

	spin_lock_irq(&dd->uctxt_lock);
	if (uctxt->urgent != uctxt->urgent_poll) {
		pollflag = POLLIN | POLLRDNORM;
		uctxt->urgent_poll = uctxt->urgent;
	} else {
		pollflag = 0;
		set_bit(HFI1_CTXT_WAITING_URG, &uctxt->event_flags);
	}
	spin_unlock_irq(&dd->uctxt_lock);

	return pollflag;
}

static unsigned int poll_next(struct file *fp,
			      struct poll_table_struct *pt)
{
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
	struct hfi1_devdata *dd = uctxt->dd;
	unsigned pollflag;

	poll_wait(fp, &uctxt->wait, pt);

	spin_lock_irq(&dd->uctxt_lock);
	if (hdrqempty(uctxt)) {
		set_bit(HFI1_CTXT_WAITING_RCV, &uctxt->event_flags);
		hfi1_rcvctrl(dd, HFI1_RCVCTRL_INTRAVAIL_ENB, uctxt->ctxt);
		pollflag = 0;
	} else
		pollflag = POLLIN | POLLRDNORM;
	spin_unlock_irq(&dd->uctxt_lock);

	return pollflag;
}

/*
 * Find all user contexts in use, and set the specified bit in their
 * event mask.
 * See also find_ctxt() for a similar use, that is specific to send buffers.
 */
int hfi1_set_uevent_bits(struct hfi1_pportdata *ppd, const int evtbit)
{
	struct hfi1_ctxtdata *uctxt;
	struct hfi1_devdata *dd = ppd->dd;
	unsigned ctxt;
	int ret = 0;
	unsigned long flags;

	if (!dd->events) {
		ret = -EINVAL;
		goto done;
	}

	spin_lock_irqsave(&dd->uctxt_lock, flags);
	for (ctxt = dd->first_user_ctxt; ctxt < dd->num_rcv_contexts;
	     ctxt++) {
		uctxt = dd->rcd[ctxt];
		if (uctxt) {
			unsigned long *evs = dd->events +
				(uctxt->ctxt - dd->first_user_ctxt) *
				HFI1_MAX_SHARED_CTXTS;
			int i;
			/*
			 * subctxt_cnt is 0 if not shared, so do base
			 * separately, first, then remaining subctxt, if any
			 */
			set_bit(evtbit, evs);
			for (i = 1; i < uctxt->subctxt_cnt; i++)
				set_bit(evtbit, evs + i);
		}
	}
	spin_unlock_irqrestore(&dd->uctxt_lock, flags);
done:
	return ret;
}

/**
 * manage_rcvq - manage a context's receive queue
 * @uctxt: the context
 * @subctxt: the sub-context
 * @start_stop: action to carry out
 *
 * start_stop == 0 disables receive on the context, for use in queue
 * overflow conditions.  start_stop==1 re-enables, to be used to
 * re-init the software copy of the head register
 */
static int manage_rcvq(struct hfi1_ctxtdata *uctxt, unsigned subctxt,
		       int start_stop)
{
	struct hfi1_devdata *dd = uctxt->dd;
	unsigned int rcvctrl_op;

	if (subctxt)
		goto bail;
	/* atomically clear receive enable ctxt. */
	if (start_stop) {
		/*
		 * On enable, force in-memory copy of the tail register to
		 * 0, so that protocol code doesn't have to worry about
		 * whether or not the chip has yet updated the in-memory
		 * copy or not on return from the system call. The chip
		 * always resets it's tail register back to 0 on a
		 * transition from disabled to enabled.
		 */
		if (uctxt->rcvhdrtail_kvaddr)
			clear_rcvhdrtail(uctxt);
		rcvctrl_op = HFI1_RCVCTRL_CTXT_ENB;
	} else
		rcvctrl_op = HFI1_RCVCTRL_CTXT_DIS;
	hfi1_rcvctrl(dd, rcvctrl_op, uctxt->ctxt);
	/* always; new head should be equal to new tail; see above */
bail:
	return 0;
}

/*
 * clear the event notifier events for this context.
 * User process then performs actions appropriate to bit having been
 * set, if desired, and checks again in future.
 */
static int user_event_ack(struct hfi1_ctxtdata *uctxt, int subctxt,
			  unsigned long events)
{
	int i;
	struct hfi1_devdata *dd = uctxt->dd;
	unsigned long *evs;

	if (!dd->events)
		return 0;

	evs = dd->events + ((uctxt->ctxt - dd->first_user_ctxt) *
			    HFI1_MAX_SHARED_CTXTS) + subctxt;

	for (i = 0; i <= _HFI1_MAX_EVENT_BIT; i++) {
		if (!test_bit(i, &events))
			continue;
		clear_bit(i, evs);
	}
	return 0;
}

#define num_user_pages(vaddr, len)					\
	(1 + (((((unsigned long)(vaddr) +				\
		 (unsigned long)(len) - 1) & PAGE_MASK) -		\
	       ((unsigned long)vaddr & PAGE_MASK)) >> PAGE_SHIFT))

/**
 * tzcnt - count the number of trailing zeros in a 64bit value
 * @value: the value to be examined
 *
 * Returns the number of trailing least significant zeros in the
 * the input value. If the value is zero, return the number of
 * bits of the value.
 */
static inline u8 tzcnt(u64 value)
{
	return value ? __builtin_ctzl(value) : sizeof(value) * 8;
}

static inline unsigned num_free_groups(unsigned long map, u16 *start)
{
	unsigned free;
	u16 bitidx = *start;

	if (bitidx >= BITS_PER_LONG)
		return 0;
	/* "Turn off" any bits set before our bit index */
	map &= ~((1ULL << bitidx) - 1);
	free = tzcnt(map) - bitidx;
	while (!free && bitidx < BITS_PER_LONG) {
		/* Zero out the last set bit so we look at the rest */
		map &= ~(1ULL << bitidx);
		/*
		 * Account for the previously checked bits and advance
		 * the bit index. We don't have to check for bitidx
		 * getting bigger than BITS_PER_LONG here as it would
		 * mean extra instructions that we don't need. If it
		 * did happen, it would push free to a negative value
		 * which will break the loop.
		 */
		free = tzcnt(map) - ++bitidx;
	}
	*start = bitidx;
	return free;
}

static int exp_tid_setup(struct file *fp, struct hfi1_tid_info *tinfo)
{
	int ret = 0;
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
	struct hfi1_devdata *dd = uctxt->dd;
	unsigned tid, mapped = 0, npages, ngroups, exp_groups,
		tidpairs = uctxt->expected_count / 2;
	struct page **pages;
	unsigned long vaddr, tidmap[uctxt->tidmapcnt];
	dma_addr_t *phys;
	u32 tidlist[tidpairs], pairidx = 0, tidcursor;
	u16 useidx, idx, bitidx, tidcnt = 0;

	vaddr = tinfo->vaddr;

	if (offset_in_page(vaddr)) {
		ret = -EINVAL;
		goto bail;
	}

	npages = num_user_pages(vaddr, tinfo->length);
	if (!npages) {
		ret = -EINVAL;
		goto bail;
	}
	if (!access_ok(VERIFY_WRITE, (void __user *)vaddr,
		       npages * PAGE_SIZE)) {
		dd_dev_err(dd, "Fail vaddr %p, %u pages, !access_ok\n",
			   (void *)vaddr, npages);
		ret = -EFAULT;
		goto bail;
	}

	memset(tidmap, 0, sizeof(tidmap[0]) * uctxt->tidmapcnt);
	memset(tidlist, 0, sizeof(tidlist[0]) * tidpairs);

	exp_groups = uctxt->expected_count / dd->rcv_entries.group_size;
	/* which group set do we look at first? */
	tidcursor = atomic_read(&uctxt->tidcursor);
	useidx = (tidcursor >> 16) & 0xffff;
	bitidx = tidcursor & 0xffff;

	/*
	 * Keep going until we've mapped all pages or we've exhausted all
	 * RcvArray entries.
	 * This iterates over the number of tidmaps + 1
	 * (idx <= uctxt->tidmapcnt) so we check the bitmap which we
	 * started from one more time for any free bits before the
	 * starting point bit.
	 */
	for (mapped = 0, idx = 0;
	     mapped < npages && idx <= uctxt->tidmapcnt;) {
		u64 i, offset = 0;
		unsigned free, pinned, pmapped = 0, bits_used;
		u16 grp;

		/*
		 * "Reserve" the needed group bits under lock so other
		 * processes can't step in the middle of it. Once
		 * reserved, we don't need the lock anymore since we
		 * are guaranteed the groups.
		 */
		spin_lock(&uctxt->exp_lock);
		if (uctxt->tidusemap[useidx] == -1ULL ||
		    bitidx >= BITS_PER_LONG) {
			/* no free groups in the set, use the next */
			useidx = (useidx + 1) % uctxt->tidmapcnt;
			idx++;
			bitidx = 0;
			spin_unlock(&uctxt->exp_lock);
			continue;
		}
		ngroups = ((npages - mapped) / dd->rcv_entries.group_size) +
			!!((npages - mapped) % dd->rcv_entries.group_size);

		/*
		 * If we've gotten here, the current set of groups does have
		 * one or more free groups.
		 */
		free = num_free_groups(uctxt->tidusemap[useidx], &bitidx);
		if (!free) {
			/*
			 * Despite the check above, free could still come back
			 * as 0 because we don't check the entire bitmap but
			 * we start from bitidx.
			 */
			spin_unlock(&uctxt->exp_lock);
			continue;
		}
		bits_used = min(free, ngroups);
		tidmap[useidx] |= ((1ULL << bits_used) - 1) << bitidx;
		uctxt->tidusemap[useidx] |= tidmap[useidx];
		spin_unlock(&uctxt->exp_lock);

		/*
		 * At this point, we know where in the map we have free bits.
		 * properly offset into the various "shadow" arrays and compute
		 * the RcvArray entry index.
		 */
		offset = ((useidx * BITS_PER_LONG) + bitidx) *
			dd->rcv_entries.group_size;
		pages = uctxt->tid_pg_list + offset;
		phys = uctxt->physshadow + offset;
		tid = uctxt->expected_base + offset;

		/* Calculate how many pages we can pin based on free bits */
		pinned = min((bits_used * dd->rcv_entries.group_size),
			     (npages - mapped));
		/*
		 * Now that we know how many free RcvArray entries we have,
		 * we can pin that many user pages.
		 */
		ret = hfi1_get_user_pages(vaddr + (mapped * PAGE_SIZE),
					  pinned, pages);
		if (ret) {
			/*
			 * We can't continue because the pages array won't be
			 * initialized. This should never happen,
			 * unless perhaps the user has mpin'ed the pages
			 * themselves.
			 */
			dd_dev_info(dd,
				    "Failed to lock addr %p, %u pages: errno %d\n",
				    (void *) vaddr, pinned, -ret);
			/*
			 * Let go of the bits that we reserved since we are not
			 * going to use them.
			 */
			spin_lock(&uctxt->exp_lock);
			uctxt->tidusemap[useidx] &=
				~(((1ULL << bits_used) - 1) << bitidx);
			spin_unlock(&uctxt->exp_lock);
			goto done;
		}
		/*
		 * How many groups do we need based on how many pages we have
		 * pinned?
		 */
		ngroups = (pinned / dd->rcv_entries.group_size) +
			!!(pinned % dd->rcv_entries.group_size);
		/*
		 * Keep programming RcvArray entries for all the <ngroups> free
		 * groups.
		 */
		for (i = 0, grp = 0; grp < ngroups; i++, grp++) {
			unsigned j;
			u32 pair_size = 0, tidsize;
			/*
			 * This inner loop will program an entire group or the
			 * array of pinned pages (which ever limit is hit
			 * first).
			 */
			for (j = 0; j < dd->rcv_entries.group_size &&
				     pmapped < pinned; j++, pmapped++, tid++) {
				tidsize = PAGE_SIZE;
				phys[pmapped] = hfi1_map_page(dd->pcidev,
						   pages[pmapped], 0,
						   tidsize, PCI_DMA_FROMDEVICE);
				trace_hfi1_exp_rcv_set(uctxt->ctxt,
						       subctxt_fp(fp),
						       tid, vaddr,
						       phys[pmapped],
						       pages[pmapped]);
				/*
				 * Each RcvArray entry is programmed with one
				 * page * worth of memory. This will handle
				 * the 8K MTU as well as anything smaller
				 * due to the fact that both entries in the
				 * RcvTidPair are programmed with a page.
				 * PSM currently does not handle anything
				 * bigger than 8K MTU, so should we even worry
				 * about 10K here?
				 */
				hfi1_put_tid(dd, tid, PT_EXPECTED,
					     phys[pmapped],
					     ilog2(tidsize >> PAGE_SHIFT) + 1);
				pair_size += tidsize >> PAGE_SHIFT;
				EXP_TID_RESET(tidlist[pairidx], LEN, pair_size);
				if (!(tid % 2)) {
					tidlist[pairidx] |=
					   EXP_TID_SET(IDX,
						(tid - uctxt->expected_base)
						       / 2);
					tidlist[pairidx] |=
						EXP_TID_SET(CTRL, 1);
					tidcnt++;
				} else {
					tidlist[pairidx] |=
						EXP_TID_SET(CTRL, 2);
					pair_size = 0;
					pairidx++;
				}
			}
			/*
			 * We've programmed the entire group (or as much of the
			 * group as we'll use. Now, it's time to push it out...
			 */
			flush_wc();
		}
		mapped += pinned;
		atomic_set(&uctxt->tidcursor,
			   (((useidx & 0xffffff) << 16) |
			    ((bitidx + bits_used) & 0xffffff)));
	}
	trace_hfi1_exp_tid_map(uctxt->ctxt, subctxt_fp(fp), 0, uctxt->tidusemap,
			       uctxt->tidmapcnt);

done:
	/* If we've mapped anything, copy relevant info to user */
	if (mapped) {
		if (copy_to_user((void __user *)(unsigned long)tinfo->tidlist,
				 tidlist, sizeof(tidlist[0]) * tidcnt)) {
			ret = -EFAULT;
			goto done;
		}
		/* copy TID info to user */
		if (copy_to_user((void __user *)(unsigned long)tinfo->tidmap,
				 tidmap, sizeof(tidmap[0]) * uctxt->tidmapcnt))
			ret = -EFAULT;
	}
bail:
	/*
	 * Calculate mapped length. New Exp TID protocol does not "unwind" and
	 * report an error if it can't map the entire buffer. It just reports
	 * the length that was mapped.
	 */
	tinfo->length = mapped * PAGE_SIZE;
	tinfo->tidcnt = tidcnt;
	return ret;
}

static int exp_tid_free(struct file *fp, struct hfi1_tid_info *tinfo)
{
	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
	struct hfi1_devdata *dd = uctxt->dd;
	unsigned long tidmap[uctxt->tidmapcnt];
	struct page **pages;
	dma_addr_t *phys;
	u16 idx, bitidx, tid;
	int ret = 0;

	if (copy_from_user(&tidmap, (void __user *)(unsigned long)
			   tinfo->tidmap,
			   sizeof(tidmap[0]) * uctxt->tidmapcnt)) {
		ret = -EFAULT;
		goto done;
	}
	for (idx = 0; idx < uctxt->tidmapcnt; idx++) {
		unsigned long map;

		bitidx = 0;
		if (!tidmap[idx])
			continue;
		map = tidmap[idx];
		while ((bitidx = tzcnt(map)) < BITS_PER_LONG) {
			int i, pcount = 0;
			struct page *pshadow[dd->rcv_entries.group_size];
			unsigned offset = ((idx * BITS_PER_LONG) + bitidx) *
				dd->rcv_entries.group_size;

			pages = uctxt->tid_pg_list + offset;
			phys = uctxt->physshadow + offset;
			tid = uctxt->expected_base + offset;
			for (i = 0; i < dd->rcv_entries.group_size;
			     i++, tid++) {
				if (pages[i]) {
					hfi1_put_tid(dd, tid, PT_INVALID,
						      0, 0);
					trace_hfi1_exp_rcv_free(uctxt->ctxt,
								subctxt_fp(fp),
								tid, phys[i],
								pages[i]);
					pci_unmap_page(dd->pcidev, phys[i],
					      PAGE_SIZE, PCI_DMA_FROMDEVICE);
					pshadow[pcount] = pages[i];
					pages[i] = NULL;
					pcount++;
					phys[i] = 0;
				}
			}
			flush_wc();
			hfi1_release_user_pages(pshadow, pcount);
			clear_bit(bitidx, &uctxt->tidusemap[idx]);
			map &= ~(1ULL<<bitidx);
		}
	}
	trace_hfi1_exp_tid_map(uctxt->ctxt, subctxt_fp(fp), 1, uctxt->tidusemap,
			       uctxt->tidmapcnt);
done:
	return ret;
}

static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt)
{
	struct hfi1_devdata *dd = uctxt->dd;
	unsigned tid;

	dd_dev_info(dd, "ctxt %u unlocking any locked expTID pages\n",
		    uctxt->ctxt);
	for (tid = 0; tid < uctxt->expected_count; tid++) {
		struct page *p = uctxt->tid_pg_list[tid];
		dma_addr_t phys;

		if (!p)
			continue;

		phys = uctxt->physshadow[tid];
		uctxt->physshadow[tid] = 0;
		uctxt->tid_pg_list[tid] = NULL;
		pci_unmap_page(dd->pcidev, phys, PAGE_SIZE, PCI_DMA_FROMDEVICE);
		hfi1_release_user_pages(&p, 1);
	}
}

static int set_ctxt_pkey(struct hfi1_ctxtdata *uctxt, unsigned subctxt,
			 u16 pkey)
{
	int ret = -ENOENT, i, intable = 0;
	struct hfi1_pportdata *ppd = uctxt->ppd;
	struct hfi1_devdata *dd = uctxt->dd;

	if (pkey == LIM_MGMT_P_KEY || pkey == FULL_MGMT_P_KEY) {
		ret = -EINVAL;
		goto done;
	}

	for (i = 0; i < ARRAY_SIZE(ppd->pkeys); i++)
		if (pkey == ppd->pkeys[i]) {
			intable = 1;
			break;
		}

	if (intable)
		ret = hfi1_set_ctxt_pkey(dd, uctxt->ctxt, pkey);
done:
	return ret;
}

static int ui_open(struct inode *inode, struct file *filp)
{
	struct hfi1_devdata *dd;

	dd = container_of(inode->i_cdev, struct hfi1_devdata, ui_cdev);
	filp->private_data = dd; /* for other methods */
	return 0;
}

static int ui_release(struct inode *inode, struct file *filp)
{
	/* nothing to do */
	return 0;
}

static loff_t ui_lseek(struct file *filp, loff_t offset, int whence)
{
	struct hfi1_devdata *dd = filp->private_data;

	switch (whence) {
	case SEEK_SET:
		break;
	case SEEK_CUR:
		offset += filp->f_pos;
		break;
	case SEEK_END:
		offset = ((dd->kregend - dd->kregbase) + DC8051_DATA_MEM_SIZE) -
			offset;
		break;
	default:
		return -EINVAL;
	}

	if (offset < 0)
		return -EINVAL;

	if (offset >= (dd->kregend - dd->kregbase) + DC8051_DATA_MEM_SIZE)
		return -EINVAL;

	filp->f_pos = offset;

	return filp->f_pos;
}


/* NOTE: assumes unsigned long is 8 bytes */
static ssize_t ui_read(struct file *filp, char __user *buf, size_t count,
			loff_t *f_pos)
{
	struct hfi1_devdata *dd = filp->private_data;
	void __iomem *base = dd->kregbase;
	unsigned long total, csr_off,
		barlen = (dd->kregend - dd->kregbase);
	u64 data;

	/* only read 8 byte quantities */
	if ((count % 8) != 0)
		return -EINVAL;
	/* offset must be 8-byte aligned */
	if ((*f_pos % 8) != 0)
		return -EINVAL;
	/* destination buffer must be 8-byte aligned */
	if ((unsigned long)buf % 8 != 0)
		return -EINVAL;
	/* must be in range */
	if (*f_pos + count > (barlen + DC8051_DATA_MEM_SIZE))
		return -EINVAL;
	/* only set the base if we are not starting past the BAR */
	if (*f_pos < barlen)
		base += *f_pos;
	csr_off = *f_pos;
	for (total = 0; total < count; total += 8, csr_off += 8) {
		/* accessing LCB CSRs requires more checks */
		if (is_lcb_offset(csr_off)) {
			if (read_lcb_csr(dd, csr_off, (u64 *)&data))
				break; /* failed */
		}
		/*
		 * Cannot read ASIC GPIO/QSFP* clear and force CSRs without a
		 * false parity error.  Avoid the whole issue by not reading
		 * them.  These registers are defined as having a read value
		 * of 0.
		 */
		else if (csr_off == ASIC_GPIO_CLEAR
				|| csr_off == ASIC_GPIO_FORCE
				|| csr_off == ASIC_QSFP1_CLEAR
				|| csr_off == ASIC_QSFP1_FORCE
				|| csr_off == ASIC_QSFP2_CLEAR
				|| csr_off == ASIC_QSFP2_FORCE)
			data = 0;
		else if (csr_off >= barlen) {
			/*
			 * read_8051_data can read more than just 8 bytes at
			 * a time. However, folding this into the loop and
			 * handling the reads in 8 byte increments allows us
			 * to smoothly transition from chip memory to 8051
			 * memory.
			 */
			if (read_8051_data(dd,
					   (u32)(csr_off - barlen),
					   sizeof(data), &data))
				break; /* failed */
		} else
			data = readq(base + total);
		if (put_user(data, (unsigned long __user *)(buf + total)))
			break;
	}
	*f_pos += total;
	return total;
}

/* NOTE: assumes unsigned long is 8 bytes */
static ssize_t ui_write(struct file *filp, const char __user *buf,
			size_t count, loff_t *f_pos)
{
	struct hfi1_devdata *dd = filp->private_data;
	void __iomem *base;
	unsigned long total, data, csr_off;
	int in_lcb;

	/* only write 8 byte quantities */
	if ((count % 8) != 0)
		return -EINVAL;
	/* offset must be 8-byte aligned */
	if ((*f_pos % 8) != 0)
		return -EINVAL;
	/* source buffer must be 8-byte aligned */
	if ((unsigned long)buf % 8 != 0)
		return -EINVAL;
	/* must be in range */
	if (*f_pos + count > dd->kregend - dd->kregbase)
		return -EINVAL;

	base = (void __iomem *)dd->kregbase + *f_pos;
	csr_off = *f_pos;
	in_lcb = 0;
	for (total = 0; total < count; total += 8, csr_off += 8) {
		if (get_user(data, (unsigned long __user *)(buf + total)))
			break;
		/* accessing LCB CSRs requires a special procedure */
		if (is_lcb_offset(csr_off)) {
			if (!in_lcb) {
				int ret = acquire_lcb_access(dd, 1);

				if (ret)
					break;
				in_lcb = 1;
			}
		} else {
			if (in_lcb) {
				release_lcb_access(dd, 1);
				in_lcb = 0;
			}
		}
		writeq(data, base + total);
	}
	if (in_lcb)
		release_lcb_access(dd, 1);
	*f_pos += total;
	return total;
}

static const struct file_operations ui_file_ops = {
	.owner = THIS_MODULE,
	.llseek = ui_lseek,
	.read = ui_read,
	.write = ui_write,
	.open = ui_open,
	.release = ui_release,
};

#define UI_OFFSET 192	/* device minor offset for UI devices */
static int create_ui = 1;

static struct cdev wildcard_cdev;
static struct device *wildcard_device;

static atomic_t user_count = ATOMIC_INIT(0);

static void user_remove(struct hfi1_devdata *dd)
{
	if (atomic_dec_return(&user_count) == 0)
		hfi1_cdev_cleanup(&wildcard_cdev, &wildcard_device);

	hfi1_cdev_cleanup(&dd->user_cdev, &dd->user_device);
	hfi1_cdev_cleanup(&dd->ui_cdev, &dd->ui_device);
}

static int user_add(struct hfi1_devdata *dd)
{
	char name[10];
	int ret;

	if (atomic_inc_return(&user_count) == 1) {
		ret = hfi1_cdev_init(0, class_name(), &hfi1_file_ops,
				     &wildcard_cdev, &wildcard_device,
				     true);
		if (ret)
			goto done;
	}

	snprintf(name, sizeof(name), "%s_%d", class_name(), dd->unit);
	ret = hfi1_cdev_init(dd->unit + 1, name, &hfi1_file_ops,
			     &dd->user_cdev, &dd->user_device,
			     true);
	if (ret)
		goto done;

	if (create_ui) {
		snprintf(name, sizeof(name),
			 "%s_ui%d", class_name(), dd->unit);
		ret = hfi1_cdev_init(dd->unit + UI_OFFSET, name, &ui_file_ops,
				     &dd->ui_cdev, &dd->ui_device,
				     false);
		if (ret)
			goto done;
	}

	return 0;
done:
	user_remove(dd);
	return ret;
}

/*
 * Create per-unit files in /dev
 */
int hfi1_device_create(struct hfi1_devdata *dd)
{
	int r, ret;

	r = user_add(dd);
	ret = hfi1_diag_add(dd);
	if (r && !ret)
		ret = r;
	return ret;
}

/*
 * Remove per-unit files in /dev
 * void, core kernel returns no errors for this stuff
 */
void hfi1_device_remove(struct hfi1_devdata *dd)
{
	user_remove(dd);
	hfi1_diag_remove(dd);
}