IB/hfi1: Move driver out of staging

The TODO list for the hfi1 driver was completed during 4.6. In addition
other objections raised (which are far beyond what was in the TODO list)
have been addressed as well. It is now time to remove the driver from
staging and into the drivers/infiniband sub-tree.

Reviewed-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 1050 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/user_exp_rcv.c b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
new file mode 100644
index 000000000000..1b640a35b3fe
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/user_exp_rcv.c
@@ -0,0 +1,1050 @@
+/*
+ * Copyright(c) 2015, 2016 Intel Corporation.
+ *
+ * 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
+ *
+ * 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
+ *
+ * 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 <asm/page.h>
+
+#include "user_exp_rcv.h"
+#include "trace.h"
+#include "mmu_rb.h"
+
+struct tid_group {
+	struct list_head list;
+	unsigned base;
+	u8 size;
+	u8 used;
+	u8 map;
+};
+
+struct tid_rb_node {
+	struct mmu_rb_node mmu;
+	unsigned long phys;
+	struct tid_group *grp;
+	u32 rcventry;
+	dma_addr_t dma_addr;
+	bool freed;
+	unsigned npages;
+	struct page *pages[0];
+};
+
+struct tid_pageset {
+	u16 idx;
+	u16 count;
+};
+
+#define EXP_TID_SET_EMPTY(set) (set.count == 0 && list_empty(&set.list))
+
+#define num_user_pages(vaddr, len)				       \
+	(1 + (((((unsigned long)(vaddr) +			       \
+		 (unsigned long)(len) - 1) & PAGE_MASK) -	       \
+	       ((unsigned long)vaddr & PAGE_MASK)) >> PAGE_SHIFT))
+
+static void unlock_exp_tids(struct hfi1_ctxtdata *, struct exp_tid_set *,
+			    struct rb_root *);
+static u32 find_phys_blocks(struct page **, unsigned, struct tid_pageset *);
+static int set_rcvarray_entry(struct file *, unsigned long, u32,
+			      struct tid_group *, struct page **, unsigned);
+static int mmu_rb_insert(struct rb_root *, struct mmu_rb_node *);
+static void mmu_rb_remove(struct rb_root *, struct mmu_rb_node *,
+			  struct mm_struct *);
+static int mmu_rb_invalidate(struct rb_root *, struct mmu_rb_node *);
+static int program_rcvarray(struct file *, unsigned long, struct tid_group *,
+			    struct tid_pageset *, unsigned, u16, struct page **,
+			    u32 *, unsigned *, unsigned *);
+static int unprogram_rcvarray(struct file *, u32, struct tid_group **);
+static void clear_tid_node(struct hfi1_filedata *, u16, struct tid_rb_node *);
+
+static struct mmu_rb_ops tid_rb_ops = {
+	.insert = mmu_rb_insert,
+	.remove = mmu_rb_remove,
+	.invalidate = mmu_rb_invalidate
+};
+
+static inline u32 rcventry2tidinfo(u32 rcventry)
+{
+	u32 pair = rcventry & ~0x1;
+
+	return EXP_TID_SET(IDX, pair >> 1) |
+		EXP_TID_SET(CTRL, 1 << (rcventry - pair));
+}
+
+static inline void exp_tid_group_init(struct exp_tid_set *set)
+{
+	INIT_LIST_HEAD(&set->list);
+	set->count = 0;
+}
+
+static inline void tid_group_remove(struct tid_group *grp,
+				    struct exp_tid_set *set)
+{
+	list_del_init(&grp->list);
+	set->count--;
+}
+
+static inline void tid_group_add_tail(struct tid_group *grp,
+				      struct exp_tid_set *set)
+{
+	list_add_tail(&grp->list, &set->list);
+	set->count++;
+}
+
+static inline struct tid_group *tid_group_pop(struct exp_tid_set *set)
+{
+	struct tid_group *grp =
+		list_first_entry(&set->list, struct tid_group, list);
+	list_del_init(&grp->list);
+	set->count--;
+	return grp;
+}
+
+static inline void tid_group_move(struct tid_group *group,
+				  struct exp_tid_set *s1,
+				  struct exp_tid_set *s2)
+{
+	tid_group_remove(group, s1);
+	tid_group_add_tail(group, s2);
+}
+
+/*
+ * Initialize context and file private data needed for Expected
+ * receive caching. This needs to be done after the context has
+ * been configured with the eager/expected RcvEntry counts.
+ */
+int hfi1_user_exp_rcv_init(struct file *fp)
+{
+	struct hfi1_filedata *fd = fp->private_data;
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct hfi1_devdata *dd = uctxt->dd;
+	unsigned tidbase;
+	int i, ret = 0;
+
+	spin_lock_init(&fd->tid_lock);
+	spin_lock_init(&fd->invalid_lock);
+	fd->tid_rb_root = RB_ROOT;
+
+	if (!uctxt->subctxt_cnt || !fd->subctxt) {
+		exp_tid_group_init(&uctxt->tid_group_list);
+		exp_tid_group_init(&uctxt->tid_used_list);
+		exp_tid_group_init(&uctxt->tid_full_list);
+
+		tidbase = uctxt->expected_base;
+		for (i = 0; i < uctxt->expected_count /
+			     dd->rcv_entries.group_size; i++) {
+			struct tid_group *grp;
+
+			grp = kzalloc(sizeof(*grp), GFP_KERNEL);
+			if (!grp) {
+				/*
+				 * If we fail here, the groups already
+				 * allocated will be freed by the close
+				 * call.
+				 */
+				ret = -ENOMEM;
+				goto done;
+			}
+			grp->size = dd->rcv_entries.group_size;
+			grp->base = tidbase;
+			tid_group_add_tail(grp, &uctxt->tid_group_list);
+			tidbase += dd->rcv_entries.group_size;
+		}
+	}
+
+	fd->entry_to_rb = kcalloc(uctxt->expected_count,
+				     sizeof(struct rb_node *),
+				     GFP_KERNEL);
+	if (!fd->entry_to_rb)
+		return -ENOMEM;
+
+	if (!HFI1_CAP_IS_USET(TID_UNMAP)) {
+		fd->invalid_tid_idx = 0;
+		fd->invalid_tids = kzalloc(uctxt->expected_count *
+					   sizeof(u32), GFP_KERNEL);
+		if (!fd->invalid_tids) {
+			ret = -ENOMEM;
+			goto done;
+		}
+
+		/*
+		 * Register MMU notifier callbacks. If the registration
+		 * fails, continue but turn off the TID caching for
+		 * all user contexts.
+		 */
+		ret = hfi1_mmu_rb_register(&fd->tid_rb_root, &tid_rb_ops);
+		if (ret) {
+			dd_dev_info(dd,
+				    "Failed MMU notifier registration %d\n",
+				    ret);
+			HFI1_CAP_USET(TID_UNMAP);
+			ret = 0;
+		}
+	}
+
+	/*
+	 * PSM does not have a good way to separate, count, and
+	 * effectively enforce a limit on RcvArray entries used by
+	 * subctxts (when context sharing is used) when TID caching
+	 * is enabled. To help with that, we calculate a per-process
+	 * RcvArray entry share and enforce that.
+	 * If TID caching is not in use, PSM deals with usage on its
+	 * own. In that case, we allow any subctxt to take all of the
+	 * entries.
+	 *
+	 * Make sure that we set the tid counts only after successful
+	 * init.
+	 */
+	spin_lock(&fd->tid_lock);
+	if (uctxt->subctxt_cnt && !HFI1_CAP_IS_USET(TID_UNMAP)) {
+		u16 remainder;
+
+		fd->tid_limit = uctxt->expected_count / uctxt->subctxt_cnt;
+		remainder = uctxt->expected_count % uctxt->subctxt_cnt;
+		if (remainder && fd->subctxt < remainder)
+			fd->tid_limit++;
+	} else {
+		fd->tid_limit = uctxt->expected_count;
+	}
+	spin_unlock(&fd->tid_lock);
+done:
+	return ret;
+}
+
+int hfi1_user_exp_rcv_free(struct hfi1_filedata *fd)
+{
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct tid_group *grp, *gptr;
+
+	if (!test_bit(HFI1_CTXT_SETUP_DONE, &uctxt->event_flags))
+		return 0;
+	/*
+	 * The notifier would have been removed when the process'es mm
+	 * was freed.
+	 */
+	if (!HFI1_CAP_IS_USET(TID_UNMAP))
+		hfi1_mmu_rb_unregister(&fd->tid_rb_root);
+
+	kfree(fd->invalid_tids);
+
+	if (!uctxt->cnt) {
+		if (!EXP_TID_SET_EMPTY(uctxt->tid_full_list))
+			unlock_exp_tids(uctxt, &uctxt->tid_full_list,
+					&fd->tid_rb_root);
+		if (!EXP_TID_SET_EMPTY(uctxt->tid_used_list))
+			unlock_exp_tids(uctxt, &uctxt->tid_used_list,
+					&fd->tid_rb_root);
+		list_for_each_entry_safe(grp, gptr, &uctxt->tid_group_list.list,
+					 list) {
+			list_del_init(&grp->list);
+			kfree(grp);
+		}
+		hfi1_clear_tids(uctxt);
+	}
+
+	kfree(fd->entry_to_rb);
+	return 0;
+}
+
+/*
+ * Write an "empty" RcvArray entry.
+ * This function exists so the TID registaration code can use it
+ * to write to unused/unneeded entries and still take advantage
+ * of the WC performance improvements. The HFI will ignore this
+ * write to the RcvArray entry.
+ */
+static inline void rcv_array_wc_fill(struct hfi1_devdata *dd, u32 index)
+{
+	/*
+	 * Doing the WC fill writes only makes sense if the device is
+	 * present and the RcvArray has been mapped as WC memory.
+	 */
+	if ((dd->flags & HFI1_PRESENT) && dd->rcvarray_wc)
+		writeq(0, dd->rcvarray_wc + (index * 8));
+}
+
+/*
+ * RcvArray entry allocation for Expected Receives is done by the
+ * following algorithm:
+ *
+ * The context keeps 3 lists of groups of RcvArray entries:
+ *   1. List of empty groups - tid_group_list
+ *      This list is created during user context creation and
+ *      contains elements which describe sets (of 8) of empty
+ *      RcvArray entries.
+ *   2. List of partially used groups - tid_used_list
+ *      This list contains sets of RcvArray entries which are
+ *      not completely used up. Another mapping request could
+ *      use some of all of the remaining entries.
+ *   3. List of full groups - tid_full_list
+ *      This is the list where sets that are completely used
+ *      up go.
+ *
+ * An attempt to optimize the usage of RcvArray entries is
+ * made by finding all sets of physically contiguous pages in a
+ * user's buffer.
+ * These physically contiguous sets are further split into
+ * sizes supported by the receive engine of the HFI. The
+ * resulting sets of pages are stored in struct tid_pageset,
+ * which describes the sets as:
+ *    * .count - number of pages in this set
+ *    * .idx - starting index into struct page ** array
+ *                    of this set
+ *
+ * From this point on, the algorithm deals with the page sets
+ * described above. The number of pagesets is divided by the
+ * RcvArray group size to produce the number of full groups
+ * needed.
+ *
+ * Groups from the 3 lists are manipulated using the following
+ * rules:
+ *   1. For each set of 8 pagesets, a complete group from
+ *      tid_group_list is taken, programmed, and moved to
+ *      the tid_full_list list.
+ *   2. For all remaining pagesets:
+ *      2.1 If the tid_used_list is empty and the tid_group_list
+ *          is empty, stop processing pageset and return only
+ *          what has been programmed up to this point.
+ *      2.2 If the tid_used_list is empty and the tid_group_list
+ *          is not empty, move a group from tid_group_list to
+ *          tid_used_list.
+ *      2.3 For each group is tid_used_group, program as much as
+ *          can fit into the group. If the group becomes fully
+ *          used, move it to tid_full_list.
+ */
+int hfi1_user_exp_rcv_setup(struct file *fp, struct hfi1_tid_info *tinfo)
+{
+	int ret = 0, need_group = 0, pinned;
+	struct hfi1_filedata *fd = fp->private_data;
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct hfi1_devdata *dd = uctxt->dd;
+	unsigned npages, ngroups, pageidx = 0, pageset_count, npagesets,
+		tididx = 0, mapped, mapped_pages = 0;
+	unsigned long vaddr = tinfo->vaddr;
+	struct page **pages = NULL;
+	u32 *tidlist = NULL;
+	struct tid_pageset *pagesets = NULL;
+
+	/* Get the number of pages the user buffer spans */
+	npages = num_user_pages(vaddr, tinfo->length);
+	if (!npages)
+		return -EINVAL;
+
+	if (npages > uctxt->expected_count) {
+		dd_dev_err(dd, "Expected buffer too big\n");
+		return -EINVAL;
+	}
+
+	/* Verify that access is OK for the user buffer */
+	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);
+		return -EFAULT;
+	}
+
+	pagesets = kcalloc(uctxt->expected_count, sizeof(*pagesets),
+			   GFP_KERNEL);
+	if (!pagesets)
+		return -ENOMEM;
+
+	/* Allocate the array of struct page pointers needed for pinning */
+	pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
+	if (!pages) {
+		ret = -ENOMEM;
+		goto bail;
+	}
+
+	/*
+	 * Pin all the pages of the user buffer. If we can't pin all the
+	 * pages, accept the amount pinned so far and program only that.
+	 * User space knows how to deal with partially programmed buffers.
+	 */
+	if (!hfi1_can_pin_pages(dd, fd->tid_n_pinned, npages)) {
+		ret = -ENOMEM;
+		goto bail;
+	}
+
+	pinned = hfi1_acquire_user_pages(vaddr, npages, true, pages);
+	if (pinned <= 0) {
+		ret = pinned;
+		goto bail;
+	}
+	fd->tid_n_pinned += npages;
+
+	/* Find sets of physically contiguous pages */
+	npagesets = find_phys_blocks(pages, pinned, pagesets);
+
+	/*
+	 * We don't need to access this under a lock since tid_used is per
+	 * process and the same process cannot be in hfi1_user_exp_rcv_clear()
+	 * and hfi1_user_exp_rcv_setup() at the same time.
+	 */
+	spin_lock(&fd->tid_lock);
+	if (fd->tid_used + npagesets > fd->tid_limit)
+		pageset_count = fd->tid_limit - fd->tid_used;
+	else
+		pageset_count = npagesets;
+	spin_unlock(&fd->tid_lock);
+
+	if (!pageset_count)
+		goto bail;
+
+	ngroups = pageset_count / dd->rcv_entries.group_size;
+	tidlist = kcalloc(pageset_count, sizeof(*tidlist), GFP_KERNEL);
+	if (!tidlist) {
+		ret = -ENOMEM;
+		goto nomem;
+	}
+
+	tididx = 0;
+
+	/*
+	 * From this point on, we are going to be using shared (between master
+	 * and subcontexts) context resources. We need to take the lock.
+	 */
+	mutex_lock(&uctxt->exp_lock);
+	/*
+	 * The first step is to program the RcvArray entries which are complete
+	 * groups.
+	 */
+	while (ngroups && uctxt->tid_group_list.count) {
+		struct tid_group *grp =
+			tid_group_pop(&uctxt->tid_group_list);
+
+		ret = program_rcvarray(fp, vaddr, grp, pagesets,
+				       pageidx, dd->rcv_entries.group_size,
+				       pages, tidlist, &tididx, &mapped);
+		/*
+		 * If there was a failure to program the RcvArray
+		 * entries for the entire group, reset the grp fields
+		 * and add the grp back to the free group list.
+		 */
+		if (ret <= 0) {
+			tid_group_add_tail(grp, &uctxt->tid_group_list);
+			hfi1_cdbg(TID,
+				  "Failed to program RcvArray group %d", ret);
+			goto unlock;
+		}
+
+		tid_group_add_tail(grp, &uctxt->tid_full_list);
+		ngroups--;
+		pageidx += ret;
+		mapped_pages += mapped;
+	}
+
+	while (pageidx < pageset_count) {
+		struct tid_group *grp, *ptr;
+		/*
+		 * If we don't have any partially used tid groups, check
+		 * if we have empty groups. If so, take one from there and
+		 * put in the partially used list.
+		 */
+		if (!uctxt->tid_used_list.count || need_group) {
+			if (!uctxt->tid_group_list.count)
+				goto unlock;
+
+			grp = tid_group_pop(&uctxt->tid_group_list);
+			tid_group_add_tail(grp, &uctxt->tid_used_list);
+			need_group = 0;
+		}
+		/*
+		 * There is an optimization opportunity here - instead of
+		 * fitting as many page sets as we can, check for a group
+		 * later on in the list that could fit all of them.
+		 */
+		list_for_each_entry_safe(grp, ptr, &uctxt->tid_used_list.list,
+					 list) {
+			unsigned use = min_t(unsigned, pageset_count - pageidx,
+					     grp->size - grp->used);
+
+			ret = program_rcvarray(fp, vaddr, grp, pagesets,
+					       pageidx, use, pages, tidlist,
+					       &tididx, &mapped);
+			if (ret < 0) {
+				hfi1_cdbg(TID,
+					  "Failed to program RcvArray entries %d",
+					  ret);
+				ret = -EFAULT;
+				goto unlock;
+			} else if (ret > 0) {
+				if (grp->used == grp->size)
+					tid_group_move(grp,
+						       &uctxt->tid_used_list,
+						       &uctxt->tid_full_list);
+				pageidx += ret;
+				mapped_pages += mapped;
+				need_group = 0;
+				/* Check if we are done so we break out early */
+				if (pageidx >= pageset_count)
+					break;
+			} else if (WARN_ON(ret == 0)) {
+				/*
+				 * If ret is 0, we did not program any entries
+				 * into this group, which can only happen if
+				 * we've screwed up the accounting somewhere.
+				 * Warn and try to continue.
+				 */
+				need_group = 1;
+			}
+		}
+	}
+unlock:
+	mutex_unlock(&uctxt->exp_lock);
+nomem:
+	hfi1_cdbg(TID, "total mapped: tidpairs:%u pages:%u (%d)", tididx,
+		  mapped_pages, ret);
+	if (tididx) {
+		spin_lock(&fd->tid_lock);
+		fd->tid_used += tididx;
+		spin_unlock(&fd->tid_lock);
+		tinfo->tidcnt = tididx;
+		tinfo->length = mapped_pages * PAGE_SIZE;
+
+		if (copy_to_user((void __user *)(unsigned long)tinfo->tidlist,
+				 tidlist, sizeof(tidlist[0]) * tididx)) {
+			/*
+			 * On failure to copy to the user level, we need to undo
+			 * everything done so far so we don't leak resources.
+			 */
+			tinfo->tidlist = (unsigned long)&tidlist;
+			hfi1_user_exp_rcv_clear(fp, tinfo);
+			tinfo->tidlist = 0;
+			ret = -EFAULT;
+			goto bail;
+		}
+	}
+
+	/*
+	 * If not everything was mapped (due to insufficient RcvArray entries,
+	 * for example), unpin all unmapped pages so we can pin them nex time.
+	 */
+	if (mapped_pages != pinned) {
+		hfi1_release_user_pages(current->mm, &pages[mapped_pages],
+					pinned - mapped_pages,
+					false);
+		fd->tid_n_pinned -= pinned - mapped_pages;
+	}
+bail:
+	kfree(pagesets);
+	kfree(pages);
+	kfree(tidlist);
+	return ret > 0 ? 0 : ret;
+}
+
+int hfi1_user_exp_rcv_clear(struct file *fp, struct hfi1_tid_info *tinfo)
+{
+	int ret = 0;
+	struct hfi1_filedata *fd = fp->private_data;
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	u32 *tidinfo;
+	unsigned tididx;
+
+	tidinfo = kcalloc(tinfo->tidcnt, sizeof(*tidinfo), GFP_KERNEL);
+	if (!tidinfo)
+		return -ENOMEM;
+
+	if (copy_from_user(tidinfo, (void __user *)(unsigned long)
+			   tinfo->tidlist, sizeof(tidinfo[0]) *
+			   tinfo->tidcnt)) {
+		ret = -EFAULT;
+		goto done;
+	}
+
+	mutex_lock(&uctxt->exp_lock);
+	for (tididx = 0; tididx < tinfo->tidcnt; tididx++) {
+		ret = unprogram_rcvarray(fp, tidinfo[tididx], NULL);
+		if (ret) {
+			hfi1_cdbg(TID, "Failed to unprogram rcv array %d",
+				  ret);
+			break;
+		}
+	}
+	spin_lock(&fd->tid_lock);
+	fd->tid_used -= tididx;
+	spin_unlock(&fd->tid_lock);
+	tinfo->tidcnt = tididx;
+	mutex_unlock(&uctxt->exp_lock);
+done:
+	kfree(tidinfo);
+	return ret;
+}
+
+int hfi1_user_exp_rcv_invalid(struct file *fp, struct hfi1_tid_info *tinfo)
+{
+	struct hfi1_filedata *fd = fp->private_data;
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	unsigned long *ev = uctxt->dd->events +
+		(((uctxt->ctxt - uctxt->dd->first_user_ctxt) *
+		  HFI1_MAX_SHARED_CTXTS) + fd->subctxt);
+	u32 *array;
+	int ret = 0;
+
+	if (!fd->invalid_tids)
+		return -EINVAL;
+
+	/*
+	 * copy_to_user() can sleep, which will leave the invalid_lock
+	 * locked and cause the MMU notifier to be blocked on the lock
+	 * for a long time.
+	 * Copy the data to a local buffer so we can release the lock.
+	 */
+	array = kcalloc(uctxt->expected_count, sizeof(*array), GFP_KERNEL);
+	if (!array)
+		return -EFAULT;
+
+	spin_lock(&fd->invalid_lock);
+	if (fd->invalid_tid_idx) {
+		memcpy(array, fd->invalid_tids, sizeof(*array) *
+		       fd->invalid_tid_idx);
+		memset(fd->invalid_tids, 0, sizeof(*fd->invalid_tids) *
+		       fd->invalid_tid_idx);
+		tinfo->tidcnt = fd->invalid_tid_idx;
+		fd->invalid_tid_idx = 0;
+		/*
+		 * Reset the user flag while still holding the lock.
+		 * Otherwise, PSM can miss events.
+		 */
+		clear_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
+	} else {
+		tinfo->tidcnt = 0;
+	}
+	spin_unlock(&fd->invalid_lock);
+
+	if (tinfo->tidcnt) {
+		if (copy_to_user((void __user *)tinfo->tidlist,
+				 array, sizeof(*array) * tinfo->tidcnt))
+			ret = -EFAULT;
+	}
+	kfree(array);
+
+	return ret;
+}
+
+static u32 find_phys_blocks(struct page **pages, unsigned npages,
+			    struct tid_pageset *list)
+{
+	unsigned pagecount, pageidx, setcount = 0, i;
+	unsigned long pfn, this_pfn;
+
+	if (!npages)
+		return 0;
+
+	/*
+	 * Look for sets of physically contiguous pages in the user buffer.
+	 * This will allow us to optimize Expected RcvArray entry usage by
+	 * using the bigger supported sizes.
+	 */
+	pfn = page_to_pfn(pages[0]);
+	for (pageidx = 0, pagecount = 1, i = 1; i <= npages; i++) {
+		this_pfn = i < npages ? page_to_pfn(pages[i]) : 0;
+
+		/*
+		 * If the pfn's are not sequential, pages are not physically
+		 * contiguous.
+		 */
+		if (this_pfn != ++pfn) {
+			/*
+			 * At this point we have to loop over the set of
+			 * physically contiguous pages and break them down it
+			 * sizes supported by the HW.
+			 * There are two main constraints:
+			 *     1. The max buffer size is MAX_EXPECTED_BUFFER.
+			 *        If the total set size is bigger than that
+			 *        program only a MAX_EXPECTED_BUFFER chunk.
+			 *     2. The buffer size has to be a power of two. If
+			 *        it is not, round down to the closes power of
+			 *        2 and program that size.
+			 */
+			while (pagecount) {
+				int maxpages = pagecount;
+				u32 bufsize = pagecount * PAGE_SIZE;
+
+				if (bufsize > MAX_EXPECTED_BUFFER)
+					maxpages =
+						MAX_EXPECTED_BUFFER >>
+						PAGE_SHIFT;
+				else if (!is_power_of_2(bufsize))
+					maxpages =
+						rounddown_pow_of_two(bufsize) >>
+						PAGE_SHIFT;
+
+				list[setcount].idx = pageidx;
+				list[setcount].count = maxpages;
+				pagecount -= maxpages;
+				pageidx += maxpages;
+				setcount++;
+			}
+			pageidx = i;
+			pagecount = 1;
+			pfn = this_pfn;
+		} else {
+			pagecount++;
+		}
+	}
+	return setcount;
+}
+
+/**
+ * program_rcvarray() - program an RcvArray group with receive buffers
+ * @fp: file pointer
+ * @vaddr: starting user virtual address
+ * @grp: RcvArray group
+ * @sets: array of struct tid_pageset holding information on physically
+ *        contiguous chunks from the user buffer
+ * @start: starting index into sets array
+ * @count: number of struct tid_pageset's to program
+ * @pages: an array of struct page * for the user buffer
+ * @tidlist: the array of u32 elements when the information about the
+ *           programmed RcvArray entries is to be encoded.
+ * @tididx: starting offset into tidlist
+ * @pmapped: (output parameter) number of pages programmed into the RcvArray
+ *           entries.
+ *
+ * This function will program up to 'count' number of RcvArray entries from the
+ * group 'grp'. To make best use of write-combining writes, the function will
+ * perform writes to the unused RcvArray entries which will be ignored by the
+ * HW. Each RcvArray entry will be programmed with a physically contiguous
+ * buffer chunk from the user's virtual buffer.
+ *
+ * Return:
+ * -EINVAL if the requested count is larger than the size of the group,
+ * -ENOMEM or -EFAULT on error from set_rcvarray_entry(), or
+ * number of RcvArray entries programmed.
+ */
+static int program_rcvarray(struct file *fp, unsigned long vaddr,
+			    struct tid_group *grp,
+			    struct tid_pageset *sets,
+			    unsigned start, u16 count, struct page **pages,
+			    u32 *tidlist, unsigned *tididx, unsigned *pmapped)
+{
+	struct hfi1_filedata *fd = fp->private_data;
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct hfi1_devdata *dd = uctxt->dd;
+	u16 idx;
+	u32 tidinfo = 0, rcventry, useidx = 0;
+	int mapped = 0;
+
+	/* Count should never be larger than the group size */
+	if (count > grp->size)
+		return -EINVAL;
+
+	/* Find the first unused entry in the group */
+	for (idx = 0; idx < grp->size; idx++) {
+		if (!(grp->map & (1 << idx))) {
+			useidx = idx;
+			break;
+		}
+		rcv_array_wc_fill(dd, grp->base + idx);
+	}
+
+	idx = 0;
+	while (idx < count) {
+		u16 npages, pageidx, setidx = start + idx;
+		int ret = 0;
+
+		/*
+		 * If this entry in the group is used, move to the next one.
+		 * If we go past the end of the group, exit the loop.
+		 */
+		if (useidx >= grp->size) {
+			break;
+		} else if (grp->map & (1 << useidx)) {
+			rcv_array_wc_fill(dd, grp->base + useidx);
+			useidx++;
+			continue;
+		}
+
+		rcventry = grp->base + useidx;
+		npages = sets[setidx].count;
+		pageidx = sets[setidx].idx;
+
+		ret = set_rcvarray_entry(fp, vaddr + (pageidx * PAGE_SIZE),
+					 rcventry, grp, pages + pageidx,
+					 npages);
+		if (ret)
+			return ret;
+		mapped += npages;
+
+		tidinfo = rcventry2tidinfo(rcventry - uctxt->expected_base) |
+			EXP_TID_SET(LEN, npages);
+		tidlist[(*tididx)++] = tidinfo;
+		grp->used++;
+		grp->map |= 1 << useidx++;
+		idx++;
+	}
+
+	/* Fill the rest of the group with "blank" writes */
+	for (; useidx < grp->size; useidx++)
+		rcv_array_wc_fill(dd, grp->base + useidx);
+	*pmapped = mapped;
+	return idx;
+}
+
+static int set_rcvarray_entry(struct file *fp, unsigned long vaddr,
+			      u32 rcventry, struct tid_group *grp,
+			      struct page **pages, unsigned npages)
+{
+	int ret;
+	struct hfi1_filedata *fd = fp->private_data;
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct tid_rb_node *node;
+	struct hfi1_devdata *dd = uctxt->dd;
+	struct rb_root *root = &fd->tid_rb_root;
+	dma_addr_t phys;
+
+	/*
+	 * Allocate the node first so we can handle a potential
+	 * failure before we've programmed anything.
+	 */
+	node = kzalloc(sizeof(*node) + (sizeof(struct page *) * npages),
+		       GFP_KERNEL);
+	if (!node)
+		return -ENOMEM;
+
+	phys = pci_map_single(dd->pcidev,
+			      __va(page_to_phys(pages[0])),
+			      npages * PAGE_SIZE, PCI_DMA_FROMDEVICE);
+	if (dma_mapping_error(&dd->pcidev->dev, phys)) {
+		dd_dev_err(dd, "Failed to DMA map Exp Rcv pages 0x%llx\n",
+			   phys);
+		kfree(node);
+		return -EFAULT;
+	}
+
+	node->mmu.addr = vaddr;
+	node->mmu.len = npages * PAGE_SIZE;
+	node->phys = page_to_phys(pages[0]);
+	node->npages = npages;
+	node->rcventry = rcventry;
+	node->dma_addr = phys;
+	node->grp = grp;
+	node->freed = false;
+	memcpy(node->pages, pages, sizeof(struct page *) * npages);
+
+	if (HFI1_CAP_IS_USET(TID_UNMAP))
+		ret = mmu_rb_insert(root, &node->mmu);
+	else
+		ret = hfi1_mmu_rb_insert(root, &node->mmu);
+
+	if (ret) {
+		hfi1_cdbg(TID, "Failed to insert RB node %u 0x%lx, 0x%lx %d",
+			  node->rcventry, node->mmu.addr, node->phys, ret);
+		pci_unmap_single(dd->pcidev, phys, npages * PAGE_SIZE,
+				 PCI_DMA_FROMDEVICE);
+		kfree(node);
+		return -EFAULT;
+	}
+	hfi1_put_tid(dd, rcventry, PT_EXPECTED, phys, ilog2(npages) + 1);
+	trace_hfi1_exp_tid_reg(uctxt->ctxt, fd->subctxt, rcventry, npages,
+			       node->mmu.addr, node->phys, phys);
+	return 0;
+}
+
+static int unprogram_rcvarray(struct file *fp, u32 tidinfo,
+			      struct tid_group **grp)
+{
+	struct hfi1_filedata *fd = fp->private_data;
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct hfi1_devdata *dd = uctxt->dd;
+	struct tid_rb_node *node;
+	u8 tidctrl = EXP_TID_GET(tidinfo, CTRL);
+	u32 tididx = EXP_TID_GET(tidinfo, IDX) << 1, rcventry;
+
+	if (tididx >= uctxt->expected_count) {
+		dd_dev_err(dd, "Invalid RcvArray entry (%u) index for ctxt %u\n",
+			   tididx, uctxt->ctxt);
+		return -EINVAL;
+	}
+
+	if (tidctrl == 0x3)
+		return -EINVAL;
+
+	rcventry = tididx + (tidctrl - 1);
+
+	node = fd->entry_to_rb[rcventry];
+	if (!node || node->rcventry != (uctxt->expected_base + rcventry))
+		return -EBADF;
+	if (HFI1_CAP_IS_USET(TID_UNMAP))
+		mmu_rb_remove(&fd->tid_rb_root, &node->mmu, NULL);
+	else
+		hfi1_mmu_rb_remove(&fd->tid_rb_root, &node->mmu);
+
+	if (grp)
+		*grp = node->grp;
+	clear_tid_node(fd, fd->subctxt, node);
+	return 0;
+}
+
+static void clear_tid_node(struct hfi1_filedata *fd, u16 subctxt,
+			   struct tid_rb_node *node)
+{
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct hfi1_devdata *dd = uctxt->dd;
+
+	trace_hfi1_exp_tid_unreg(uctxt->ctxt, fd->subctxt, node->rcventry,
+				 node->npages, node->mmu.addr, node->phys,
+				 node->dma_addr);
+
+	hfi1_put_tid(dd, node->rcventry, PT_INVALID, 0, 0);
+	/*
+	 * Make sure device has seen the write before we unpin the
+	 * pages.
+	 */
+	flush_wc();
+
+	pci_unmap_single(dd->pcidev, node->dma_addr, node->mmu.len,
+			 PCI_DMA_FROMDEVICE);
+	hfi1_release_user_pages(current->mm, node->pages, node->npages, true);
+	fd->tid_n_pinned -= node->npages;
+
+	node->grp->used--;
+	node->grp->map &= ~(1 << (node->rcventry - node->grp->base));
+
+	if (node->grp->used == node->grp->size - 1)
+		tid_group_move(node->grp, &uctxt->tid_full_list,
+			       &uctxt->tid_used_list);
+	else if (!node->grp->used)
+		tid_group_move(node->grp, &uctxt->tid_used_list,
+			       &uctxt->tid_group_list);
+	kfree(node);
+}
+
+static void unlock_exp_tids(struct hfi1_ctxtdata *uctxt,
+			    struct exp_tid_set *set, struct rb_root *root)
+{
+	struct tid_group *grp, *ptr;
+	struct hfi1_filedata *fd = container_of(root, struct hfi1_filedata,
+						tid_rb_root);
+	int i;
+
+	list_for_each_entry_safe(grp, ptr, &set->list, list) {
+		list_del_init(&grp->list);
+
+		for (i = 0; i < grp->size; i++) {
+			if (grp->map & (1 << i)) {
+				u16 rcventry = grp->base + i;
+				struct tid_rb_node *node;
+
+				node = fd->entry_to_rb[rcventry -
+							  uctxt->expected_base];
+				if (!node || node->rcventry != rcventry)
+					continue;
+				if (HFI1_CAP_IS_USET(TID_UNMAP))
+					mmu_rb_remove(&fd->tid_rb_root,
+						      &node->mmu, NULL);
+				else
+					hfi1_mmu_rb_remove(&fd->tid_rb_root,
+							   &node->mmu);
+				clear_tid_node(fd, -1, node);
+			}
+		}
+	}
+}
+
+static int mmu_rb_invalidate(struct rb_root *root, struct mmu_rb_node *mnode)
+{
+	struct hfi1_filedata *fdata =
+		container_of(root, struct hfi1_filedata, tid_rb_root);
+	struct hfi1_ctxtdata *uctxt = fdata->uctxt;
+	struct tid_rb_node *node =
+		container_of(mnode, struct tid_rb_node, mmu);
+
+	if (node->freed)
+		return 0;
+
+	trace_hfi1_exp_tid_inval(uctxt->ctxt, fdata->subctxt, node->mmu.addr,
+				 node->rcventry, node->npages, node->dma_addr);
+	node->freed = true;
+
+	spin_lock(&fdata->invalid_lock);
+	if (fdata->invalid_tid_idx < uctxt->expected_count) {
+		fdata->invalid_tids[fdata->invalid_tid_idx] =
+			rcventry2tidinfo(node->rcventry - uctxt->expected_base);
+		fdata->invalid_tids[fdata->invalid_tid_idx] |=
+			EXP_TID_SET(LEN, node->npages);
+		if (!fdata->invalid_tid_idx) {
+			unsigned long *ev;
+
+			/*
+			 * hfi1_set_uevent_bits() sets a user event flag
+			 * for all processes. Because calling into the
+			 * driver to process TID cache invalidations is
+			 * expensive and TID cache invalidations are
+			 * handled on a per-process basis, we can
+			 * optimize this to set the flag only for the
+			 * process in question.
+			 */
+			ev = uctxt->dd->events +
+				(((uctxt->ctxt - uctxt->dd->first_user_ctxt) *
+				  HFI1_MAX_SHARED_CTXTS) + fdata->subctxt);
+			set_bit(_HFI1_EVENT_TID_MMU_NOTIFY_BIT, ev);
+		}
+		fdata->invalid_tid_idx++;
+	}
+	spin_unlock(&fdata->invalid_lock);
+	return 0;
+}
+
+static int mmu_rb_insert(struct rb_root *root, struct mmu_rb_node *node)
+{
+	struct hfi1_filedata *fdata =
+		container_of(root, struct hfi1_filedata, tid_rb_root);
+	struct tid_rb_node *tnode =
+		container_of(node, struct tid_rb_node, mmu);
+	u32 base = fdata->uctxt->expected_base;
+
+	fdata->entry_to_rb[tnode->rcventry - base] = tnode;
+	return 0;
+}
+
+static void mmu_rb_remove(struct rb_root *root, struct mmu_rb_node *node,
+			  struct mm_struct *mm)
+{
+	struct hfi1_filedata *fdata =
+		container_of(root, struct hfi1_filedata, tid_rb_root);
+	struct tid_rb_node *tnode =
+		container_of(node, struct tid_rb_node, mmu);
+	u32 base = fdata->uctxt->expected_base;
+
+	fdata->entry_to_rb[tnode->rcventry - base] = NULL;
+}