Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3220 insertions, 0 deletions

diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
new file mode 100644
index 0000000000..dc83d0ac6a
--- /dev/null
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -0,0 +1,3220 @@
+// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
+/*
+ * Copyright(c) 2016 - 2020 Intel Corporation.
+ */
+
+#include <linux/hash.h>
+#include <linux/bitops.h>
+#include <linux/lockdep.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/ib_hdrs.h>
+#include <rdma/opa_addr.h>
+#include <rdma/uverbs_ioctl.h>
+#include "qp.h"
+#include "vt.h"
+#include "trace.h"
+
+#define RVT_RWQ_COUNT_THRESHOLD 16
+
+static void rvt_rc_timeout(struct timer_list *t);
+static void rvt_reset_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp,
+			 enum ib_qp_type type);
+
+/*
+ * Convert the AETH RNR timeout code into the number of microseconds.
+ */
+static const u32 ib_rvt_rnr_table[32] = {
+	655360, /* 00: 655.36 */
+	10,     /* 01:    .01 */
+	20,     /* 02     .02 */
+	30,     /* 03:    .03 */
+	40,     /* 04:    .04 */
+	60,     /* 05:    .06 */
+	80,     /* 06:    .08 */
+	120,    /* 07:    .12 */
+	160,    /* 08:    .16 */
+	240,    /* 09:    .24 */
+	320,    /* 0A:    .32 */
+	480,    /* 0B:    .48 */
+	640,    /* 0C:    .64 */
+	960,    /* 0D:    .96 */
+	1280,   /* 0E:   1.28 */
+	1920,   /* 0F:   1.92 */
+	2560,   /* 10:   2.56 */
+	3840,   /* 11:   3.84 */
+	5120,   /* 12:   5.12 */
+	7680,   /* 13:   7.68 */
+	10240,  /* 14:  10.24 */
+	15360,  /* 15:  15.36 */
+	20480,  /* 16:  20.48 */
+	30720,  /* 17:  30.72 */
+	40960,  /* 18:  40.96 */
+	61440,  /* 19:  61.44 */
+	81920,  /* 1A:  81.92 */
+	122880, /* 1B: 122.88 */
+	163840, /* 1C: 163.84 */
+	245760, /* 1D: 245.76 */
+	327680, /* 1E: 327.68 */
+	491520  /* 1F: 491.52 */
+};
+
+/*
+ * Note that it is OK to post send work requests in the SQE and ERR
+ * states; rvt_do_send() will process them and generate error
+ * completions as per IB 1.2 C10-96.
+ */
+const int ib_rvt_state_ops[IB_QPS_ERR + 1] = {
+	[IB_QPS_RESET] = 0,
+	[IB_QPS_INIT] = RVT_POST_RECV_OK,
+	[IB_QPS_RTR] = RVT_POST_RECV_OK | RVT_PROCESS_RECV_OK,
+	[IB_QPS_RTS] = RVT_POST_RECV_OK | RVT_PROCESS_RECV_OK |
+	    RVT_POST_SEND_OK | RVT_PROCESS_SEND_OK |
+	    RVT_PROCESS_NEXT_SEND_OK,
+	[IB_QPS_SQD] = RVT_POST_RECV_OK | RVT_PROCESS_RECV_OK |
+	    RVT_POST_SEND_OK | RVT_PROCESS_SEND_OK,
+	[IB_QPS_SQE] = RVT_POST_RECV_OK | RVT_PROCESS_RECV_OK |
+	    RVT_POST_SEND_OK | RVT_FLUSH_SEND,
+	[IB_QPS_ERR] = RVT_POST_RECV_OK | RVT_FLUSH_RECV |
+	    RVT_POST_SEND_OK | RVT_FLUSH_SEND,
+};
+EXPORT_SYMBOL(ib_rvt_state_ops);
+
+/* platform specific: return the last level cache (llc) size, in KiB */
+static int rvt_wss_llc_size(void)
+{
+	/* assume that the boot CPU value is universal for all CPUs */
+	return boot_cpu_data.x86_cache_size;
+}
+
+/* platform specific: cacheless copy */
+static void cacheless_memcpy(void *dst, void *src, size_t n)
+{
+	/*
+	 * Use the only available X64 cacheless copy.  Add a __user cast
+	 * to quiet sparse.  The src agument is already in the kernel so
+	 * there are no security issues.  The extra fault recovery machinery
+	 * is not invoked.
+	 */
+	__copy_user_nocache(dst, (void __user *)src, n);
+}
+
+void rvt_wss_exit(struct rvt_dev_info *rdi)
+{
+	struct rvt_wss *wss = rdi->wss;
+
+	if (!wss)
+		return;
+
+	/* coded to handle partially initialized and repeat callers */
+	kfree(wss->entries);
+	wss->entries = NULL;
+	kfree(rdi->wss);
+	rdi->wss = NULL;
+}
+
+/*
+ * rvt_wss_init - Init wss data structures
+ *
+ * Return: 0 on success
+ */
+int rvt_wss_init(struct rvt_dev_info *rdi)
+{
+	unsigned int sge_copy_mode = rdi->dparms.sge_copy_mode;
+	unsigned int wss_threshold = rdi->dparms.wss_threshold;
+	unsigned int wss_clean_period = rdi->dparms.wss_clean_period;
+	long llc_size;
+	long llc_bits;
+	long table_size;
+	long table_bits;
+	struct rvt_wss *wss;
+	int node = rdi->dparms.node;
+
+	if (sge_copy_mode != RVT_SGE_COPY_ADAPTIVE) {
+		rdi->wss = NULL;
+		return 0;
+	}
+
+	rdi->wss = kzalloc_node(sizeof(*rdi->wss), GFP_KERNEL, node);
+	if (!rdi->wss)
+		return -ENOMEM;
+	wss = rdi->wss;
+
+	/* check for a valid percent range - default to 80 if none or invalid */
+	if (wss_threshold < 1 || wss_threshold > 100)
+		wss_threshold = 80;
+
+	/* reject a wildly large period */
+	if (wss_clean_period > 1000000)
+		wss_clean_period = 256;
+
+	/* reject a zero period */
+	if (wss_clean_period == 0)
+		wss_clean_period = 1;
+
+	/*
+	 * Calculate the table size - the next power of 2 larger than the
+	 * LLC size.  LLC size is in KiB.
+	 */
+	llc_size = rvt_wss_llc_size() * 1024;
+	table_size = roundup_pow_of_two(llc_size);
+
+	/* one bit per page in rounded up table */
+	llc_bits = llc_size / PAGE_SIZE;
+	table_bits = table_size / PAGE_SIZE;
+	wss->pages_mask = table_bits - 1;
+	wss->num_entries = table_bits / BITS_PER_LONG;
+
+	wss->threshold = (llc_bits * wss_threshold) / 100;
+	if (wss->threshold == 0)
+		wss->threshold = 1;
+
+	wss->clean_period = wss_clean_period;
+	atomic_set(&wss->clean_counter, wss_clean_period);
+
+	wss->entries = kcalloc_node(wss->num_entries, sizeof(*wss->entries),
+				    GFP_KERNEL, node);
+	if (!wss->entries) {
+		rvt_wss_exit(rdi);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/*
+ * Advance the clean counter.  When the clean period has expired,
+ * clean an entry.
+ *
+ * This is implemented in atomics to avoid locking.  Because multiple
+ * variables are involved, it can be racy which can lead to slightly
+ * inaccurate information.  Since this is only a heuristic, this is
+ * OK.  Any innaccuracies will clean themselves out as the counter
+ * advances.  That said, it is unlikely the entry clean operation will
+ * race - the next possible racer will not start until the next clean
+ * period.
+ *
+ * The clean counter is implemented as a decrement to zero.  When zero
+ * is reached an entry is cleaned.
+ */
+static void wss_advance_clean_counter(struct rvt_wss *wss)
+{
+	int entry;
+	int weight;
+	unsigned long bits;
+
+	/* become the cleaner if we decrement the counter to zero */
+	if (atomic_dec_and_test(&wss->clean_counter)) {
+		/*
+		 * Set, not add, the clean period.  This avoids an issue
+		 * where the counter could decrement below the clean period.
+		 * Doing a set can result in lost decrements, slowing the
+		 * clean advance.  Since this a heuristic, this possible
+		 * slowdown is OK.
+		 *
+		 * An alternative is to loop, advancing the counter by a
+		 * clean period until the result is > 0. However, this could
+		 * lead to several threads keeping another in the clean loop.
+		 * This could be mitigated by limiting the number of times
+		 * we stay in the loop.
+		 */
+		atomic_set(&wss->clean_counter, wss->clean_period);
+
+		/*
+		 * Uniquely grab the entry to clean and move to next.
+		 * The current entry is always the lower bits of
+		 * wss.clean_entry.  The table size, wss.num_entries,
+		 * is always a power-of-2.
+		 */
+		entry = (atomic_inc_return(&wss->clean_entry) - 1)
+			& (wss->num_entries - 1);
+
+		/* clear the entry and count the bits */
+		bits = xchg(&wss->entries[entry], 0);
+		weight = hweight64((u64)bits);
+		/* only adjust the contended total count if needed */
+		if (weight)
+			atomic_sub(weight, &wss->total_count);
+	}
+}
+
+/*
+ * Insert the given address into the working set array.
+ */
+static void wss_insert(struct rvt_wss *wss, void *address)
+{
+	u32 page = ((unsigned long)address >> PAGE_SHIFT) & wss->pages_mask;
+	u32 entry = page / BITS_PER_LONG; /* assumes this ends up a shift */
+	u32 nr = page & (BITS_PER_LONG - 1);
+
+	if (!test_and_set_bit(nr, &wss->entries[entry]))
+		atomic_inc(&wss->total_count);
+
+	wss_advance_clean_counter(wss);
+}
+
+/*
+ * Is the working set larger than the threshold?
+ */
+static inline bool wss_exceeds_threshold(struct rvt_wss *wss)
+{
+	return atomic_read(&wss->total_count) >= wss->threshold;
+}
+
+static void get_map_page(struct rvt_qpn_table *qpt,
+			 struct rvt_qpn_map *map)
+{
+	unsigned long page = get_zeroed_page(GFP_KERNEL);
+
+	/*
+	 * Free the page if someone raced with us installing it.
+	 */
+
+	spin_lock(&qpt->lock);
+	if (map->page)
+		free_page(page);
+	else
+		map->page = (void *)page;
+	spin_unlock(&qpt->lock);
+}
+
+/**
+ * init_qpn_table - initialize the QP number table for a device
+ * @rdi: rvt dev struct
+ * @qpt: the QPN table
+ */
+static int init_qpn_table(struct rvt_dev_info *rdi, struct rvt_qpn_table *qpt)
+{
+	u32 offset, i;
+	struct rvt_qpn_map *map;
+	int ret = 0;
+
+	if (!(rdi->dparms.qpn_res_end >= rdi->dparms.qpn_res_start))
+		return -EINVAL;
+
+	spin_lock_init(&qpt->lock);
+
+	qpt->last = rdi->dparms.qpn_start;
+	qpt->incr = rdi->dparms.qpn_inc << rdi->dparms.qos_shift;
+
+	/*
+	 * Drivers may want some QPs beyond what we need for verbs let them use
+	 * our qpn table. No need for two. Lets go ahead and mark the bitmaps
+	 * for those. The reserved range must be *after* the range which verbs
+	 * will pick from.
+	 */
+
+	/* Figure out number of bit maps needed before reserved range */
+	qpt->nmaps = rdi->dparms.qpn_res_start / RVT_BITS_PER_PAGE;
+
+	/* This should always be zero */
+	offset = rdi->dparms.qpn_res_start & RVT_BITS_PER_PAGE_MASK;
+
+	/* Starting with the first reserved bit map */
+	map = &qpt->map[qpt->nmaps];
+
+	rvt_pr_info(rdi, "Reserving QPNs from 0x%x to 0x%x for non-verbs use\n",
+		    rdi->dparms.qpn_res_start, rdi->dparms.qpn_res_end);
+	for (i = rdi->dparms.qpn_res_start; i <= rdi->dparms.qpn_res_end; i++) {
+		if (!map->page) {
+			get_map_page(qpt, map);
+			if (!map->page) {
+				ret = -ENOMEM;
+				break;
+			}
+		}
+		set_bit(offset, map->page);
+		offset++;
+		if (offset == RVT_BITS_PER_PAGE) {
+			/* next page */
+			qpt->nmaps++;
+			map++;
+			offset = 0;
+		}
+	}
+	return ret;
+}
+
+/**
+ * free_qpn_table - free the QP number table for a device
+ * @qpt: the QPN table
+ */
+static void free_qpn_table(struct rvt_qpn_table *qpt)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(qpt->map); i++)
+		free_page((unsigned long)qpt->map[i].page);
+}
+
+/**
+ * rvt_driver_qp_init - Init driver qp resources
+ * @rdi: rvt dev strucutre
+ *
+ * Return: 0 on success
+ */
+int rvt_driver_qp_init(struct rvt_dev_info *rdi)
+{
+	int i;
+	int ret = -ENOMEM;
+
+	if (!rdi->dparms.qp_table_size)
+		return -EINVAL;
+
+	/*
+	 * If driver is not doing any QP allocation then make sure it is
+	 * providing the necessary QP functions.
+	 */
+	if (!rdi->driver_f.free_all_qps ||
+	    !rdi->driver_f.qp_priv_alloc ||
+	    !rdi->driver_f.qp_priv_free ||
+	    !rdi->driver_f.notify_qp_reset ||
+	    !rdi->driver_f.notify_restart_rc)
+		return -EINVAL;
+
+	/* allocate parent object */
+	rdi->qp_dev = kzalloc_node(sizeof(*rdi->qp_dev), GFP_KERNEL,
+				   rdi->dparms.node);
+	if (!rdi->qp_dev)
+		return -ENOMEM;
+
+	/* allocate hash table */
+	rdi->qp_dev->qp_table_size = rdi->dparms.qp_table_size;
+	rdi->qp_dev->qp_table_bits = ilog2(rdi->dparms.qp_table_size);
+	rdi->qp_dev->qp_table =
+		kmalloc_array_node(rdi->qp_dev->qp_table_size,
+			     sizeof(*rdi->qp_dev->qp_table),
+			     GFP_KERNEL, rdi->dparms.node);
+	if (!rdi->qp_dev->qp_table)
+		goto no_qp_table;
+
+	for (i = 0; i < rdi->qp_dev->qp_table_size; i++)
+		RCU_INIT_POINTER(rdi->qp_dev->qp_table[i], NULL);
+
+	spin_lock_init(&rdi->qp_dev->qpt_lock);
+
+	/* initialize qpn map */
+	if (init_qpn_table(rdi, &rdi->qp_dev->qpn_table))
+		goto fail_table;
+
+	spin_lock_init(&rdi->n_qps_lock);
+
+	return 0;
+
+fail_table:
+	kfree(rdi->qp_dev->qp_table);
+	free_qpn_table(&rdi->qp_dev->qpn_table);
+
+no_qp_table:
+	kfree(rdi->qp_dev);
+
+	return ret;
+}
+
+/**
+ * rvt_free_qp_cb - callback function to reset a qp
+ * @qp: the qp to reset
+ * @v: a 64-bit value
+ *
+ * This function resets the qp and removes it from the
+ * qp hash table.
+ */
+static void rvt_free_qp_cb(struct rvt_qp *qp, u64 v)
+{
+	unsigned int *qp_inuse = (unsigned int *)v;
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+
+	/* Reset the qp and remove it from the qp hash list */
+	rvt_reset_qp(rdi, qp, qp->ibqp.qp_type);
+
+	/* Increment the qp_inuse count */
+	(*qp_inuse)++;
+}
+
+/**
+ * rvt_free_all_qps - check for QPs still in use
+ * @rdi: rvt device info structure
+ *
+ * There should not be any QPs still in use.
+ * Free memory for table.
+ * Return the number of QPs still in use.
+ */
+static unsigned rvt_free_all_qps(struct rvt_dev_info *rdi)
+{
+	unsigned int qp_inuse = 0;
+
+	qp_inuse += rvt_mcast_tree_empty(rdi);
+
+	rvt_qp_iter(rdi, (u64)&qp_inuse, rvt_free_qp_cb);
+
+	return qp_inuse;
+}
+
+/**
+ * rvt_qp_exit - clean up qps on device exit
+ * @rdi: rvt dev structure
+ *
+ * Check for qp leaks and free resources.
+ */
+void rvt_qp_exit(struct rvt_dev_info *rdi)
+{
+	u32 qps_inuse = rvt_free_all_qps(rdi);
+
+	if (qps_inuse)
+		rvt_pr_err(rdi, "QP memory leak! %u still in use\n",
+			   qps_inuse);
+
+	kfree(rdi->qp_dev->qp_table);
+	free_qpn_table(&rdi->qp_dev->qpn_table);
+	kfree(rdi->qp_dev);
+}
+
+static inline unsigned mk_qpn(struct rvt_qpn_table *qpt,
+			      struct rvt_qpn_map *map, unsigned off)
+{
+	return (map - qpt->map) * RVT_BITS_PER_PAGE + off;
+}
+
+/**
+ * alloc_qpn - Allocate the next available qpn or zero/one for QP type
+ *	       IB_QPT_SMI/IB_QPT_GSI
+ * @rdi: rvt device info structure
+ * @qpt: queue pair number table pointer
+ * @type: the QP type
+ * @port_num: IB port number, 1 based, comes from core
+ * @exclude_prefix: prefix of special queue pair number being allocated
+ *
+ * Return: The queue pair number
+ */
+static int alloc_qpn(struct rvt_dev_info *rdi, struct rvt_qpn_table *qpt,
+		     enum ib_qp_type type, u8 port_num, u8 exclude_prefix)
+{
+	u32 i, offset, max_scan, qpn;
+	struct rvt_qpn_map *map;
+	u32 ret;
+	u32 max_qpn = exclude_prefix == RVT_AIP_QP_PREFIX ?
+		RVT_AIP_QPN_MAX : RVT_QPN_MAX;
+
+	if (rdi->driver_f.alloc_qpn)
+		return rdi->driver_f.alloc_qpn(rdi, qpt, type, port_num);
+
+	if (type == IB_QPT_SMI || type == IB_QPT_GSI) {
+		unsigned n;
+
+		ret = type == IB_QPT_GSI;
+		n = 1 << (ret + 2 * (port_num - 1));
+		spin_lock(&qpt->lock);
+		if (qpt->flags & n)
+			ret = -EINVAL;
+		else
+			qpt->flags |= n;
+		spin_unlock(&qpt->lock);
+		goto bail;
+	}
+
+	qpn = qpt->last + qpt->incr;
+	if (qpn >= max_qpn)
+		qpn = qpt->incr | ((qpt->last & 1) ^ 1);
+	/* offset carries bit 0 */
+	offset = qpn & RVT_BITS_PER_PAGE_MASK;
+	map = &qpt->map[qpn / RVT_BITS_PER_PAGE];
+	max_scan = qpt->nmaps - !offset;
+	for (i = 0;;) {
+		if (unlikely(!map->page)) {
+			get_map_page(qpt, map);
+			if (unlikely(!map->page))
+				break;
+		}
+		do {
+			if (!test_and_set_bit(offset, map->page)) {
+				qpt->last = qpn;
+				ret = qpn;
+				goto bail;
+			}
+			offset += qpt->incr;
+			/*
+			 * This qpn might be bogus if offset >= BITS_PER_PAGE.
+			 * That is OK.   It gets re-assigned below
+			 */
+			qpn = mk_qpn(qpt, map, offset);
+		} while (offset < RVT_BITS_PER_PAGE && qpn < RVT_QPN_MAX);
+		/*
+		 * In order to keep the number of pages allocated to a
+		 * minimum, we scan the all existing pages before increasing
+		 * the size of the bitmap table.
+		 */
+		if (++i > max_scan) {
+			if (qpt->nmaps == RVT_QPNMAP_ENTRIES)
+				break;
+			map = &qpt->map[qpt->nmaps++];
+			/* start at incr with current bit 0 */
+			offset = qpt->incr | (offset & 1);
+		} else if (map < &qpt->map[qpt->nmaps]) {
+			++map;
+			/* start at incr with current bit 0 */
+			offset = qpt->incr | (offset & 1);
+		} else {
+			map = &qpt->map[0];
+			/* wrap to first map page, invert bit 0 */
+			offset = qpt->incr | ((offset & 1) ^ 1);
+		}
+		/* there can be no set bits in low-order QoS bits */
+		WARN_ON(rdi->dparms.qos_shift > 1 &&
+			offset & ((BIT(rdi->dparms.qos_shift - 1) - 1) << 1));
+		qpn = mk_qpn(qpt, map, offset);
+	}
+
+	ret = -ENOMEM;
+
+bail:
+	return ret;
+}
+
+/**
+ * rvt_clear_mr_refs - Drop help mr refs
+ * @qp: rvt qp data structure
+ * @clr_sends: If shoudl clear send side or not
+ */
+static void rvt_clear_mr_refs(struct rvt_qp *qp, int clr_sends)
+{
+	unsigned n;
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+
+	if (test_and_clear_bit(RVT_R_REWIND_SGE, &qp->r_aflags))
+		rvt_put_ss(&qp->s_rdma_read_sge);
+
+	rvt_put_ss(&qp->r_sge);
+
+	if (clr_sends) {
+		while (qp->s_last != qp->s_head) {
+			struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, qp->s_last);
+
+			rvt_put_qp_swqe(qp, wqe);
+			if (++qp->s_last >= qp->s_size)
+				qp->s_last = 0;
+			smp_wmb(); /* see qp_set_savail */
+		}
+		if (qp->s_rdma_mr) {
+			rvt_put_mr(qp->s_rdma_mr);
+			qp->s_rdma_mr = NULL;
+		}
+	}
+
+	for (n = 0; qp->s_ack_queue && n < rvt_max_atomic(rdi); n++) {
+		struct rvt_ack_entry *e = &qp->s_ack_queue[n];
+
+		if (e->rdma_sge.mr) {
+			rvt_put_mr(e->rdma_sge.mr);
+			e->rdma_sge.mr = NULL;
+		}
+	}
+}
+
+/**
+ * rvt_swqe_has_lkey - return true if lkey is used by swqe
+ * @wqe: the send wqe
+ * @lkey: the lkey
+ *
+ * Test the swqe for using lkey
+ */
+static bool rvt_swqe_has_lkey(struct rvt_swqe *wqe, u32 lkey)
+{
+	int i;
+
+	for (i = 0; i < wqe->wr.num_sge; i++) {
+		struct rvt_sge *sge = &wqe->sg_list[i];
+
+		if (rvt_mr_has_lkey(sge->mr, lkey))
+			return true;
+	}
+	return false;
+}
+
+/**
+ * rvt_qp_sends_has_lkey - return true is qp sends use lkey
+ * @qp: the rvt_qp
+ * @lkey: the lkey
+ */
+static bool rvt_qp_sends_has_lkey(struct rvt_qp *qp, u32 lkey)
+{
+	u32 s_last = qp->s_last;
+
+	while (s_last != qp->s_head) {
+		struct rvt_swqe *wqe = rvt_get_swqe_ptr(qp, s_last);
+
+		if (rvt_swqe_has_lkey(wqe, lkey))
+			return true;
+
+		if (++s_last >= qp->s_size)
+			s_last = 0;
+	}
+	if (qp->s_rdma_mr)
+		if (rvt_mr_has_lkey(qp->s_rdma_mr, lkey))
+			return true;
+	return false;
+}
+
+/**
+ * rvt_qp_acks_has_lkey - return true if acks have lkey
+ * @qp: the qp
+ * @lkey: the lkey
+ */
+static bool rvt_qp_acks_has_lkey(struct rvt_qp *qp, u32 lkey)
+{
+	int i;
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+
+	for (i = 0; qp->s_ack_queue && i < rvt_max_atomic(rdi); i++) {
+		struct rvt_ack_entry *e = &qp->s_ack_queue[i];
+
+		if (rvt_mr_has_lkey(e->rdma_sge.mr, lkey))
+			return true;
+	}
+	return false;
+}
+
+/**
+ * rvt_qp_mr_clean - clean up remote ops for lkey
+ * @qp: the qp
+ * @lkey: the lkey that is being de-registered
+ *
+ * This routine checks if the lkey is being used by
+ * the qp.
+ *
+ * If so, the qp is put into an error state to elminate
+ * any references from the qp.
+ */
+void rvt_qp_mr_clean(struct rvt_qp *qp, u32 lkey)
+{
+	bool lastwqe = false;
+
+	if (qp->ibqp.qp_type == IB_QPT_SMI ||
+	    qp->ibqp.qp_type == IB_QPT_GSI)
+		/* avoid special QPs */
+		return;
+	spin_lock_irq(&qp->r_lock);
+	spin_lock(&qp->s_hlock);
+	spin_lock(&qp->s_lock);
+
+	if (qp->state == IB_QPS_ERR || qp->state == IB_QPS_RESET)
+		goto check_lwqe;
+
+	if (rvt_ss_has_lkey(&qp->r_sge, lkey) ||
+	    rvt_qp_sends_has_lkey(qp, lkey) ||
+	    rvt_qp_acks_has_lkey(qp, lkey))
+		lastwqe = rvt_error_qp(qp, IB_WC_LOC_PROT_ERR);
+check_lwqe:
+	spin_unlock(&qp->s_lock);
+	spin_unlock(&qp->s_hlock);
+	spin_unlock_irq(&qp->r_lock);
+	if (lastwqe) {
+		struct ib_event ev;
+
+		ev.device = qp->ibqp.device;
+		ev.element.qp = &qp->ibqp;
+		ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
+		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
+	}
+}
+
+/**
+ * rvt_remove_qp - remove qp form table
+ * @rdi: rvt dev struct
+ * @qp: qp to remove
+ *
+ * Remove the QP from the table so it can't be found asynchronously by
+ * the receive routine.
+ */
+static void rvt_remove_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp)
+{
+	struct rvt_ibport *rvp = rdi->ports[qp->port_num - 1];
+	u32 n = hash_32(qp->ibqp.qp_num, rdi->qp_dev->qp_table_bits);
+	unsigned long flags;
+	int removed = 1;
+
+	spin_lock_irqsave(&rdi->qp_dev->qpt_lock, flags);
+
+	if (rcu_dereference_protected(rvp->qp[0],
+			lockdep_is_held(&rdi->qp_dev->qpt_lock)) == qp) {
+		RCU_INIT_POINTER(rvp->qp[0], NULL);
+	} else if (rcu_dereference_protected(rvp->qp[1],
+			lockdep_is_held(&rdi->qp_dev->qpt_lock)) == qp) {
+		RCU_INIT_POINTER(rvp->qp[1], NULL);
+	} else {
+		struct rvt_qp *q;
+		struct rvt_qp __rcu **qpp;
+
+		removed = 0;
+		qpp = &rdi->qp_dev->qp_table[n];
+		for (; (q = rcu_dereference_protected(*qpp,
+			lockdep_is_held(&rdi->qp_dev->qpt_lock))) != NULL;
+			qpp = &q->next) {
+			if (q == qp) {
+				RCU_INIT_POINTER(*qpp,
+				     rcu_dereference_protected(qp->next,
+				     lockdep_is_held(&rdi->qp_dev->qpt_lock)));
+				removed = 1;
+				trace_rvt_qpremove(qp, n);
+				break;
+			}
+		}
+	}
+
+	spin_unlock_irqrestore(&rdi->qp_dev->qpt_lock, flags);
+	if (removed) {
+		synchronize_rcu();
+		rvt_put_qp(qp);
+	}
+}
+
+/**
+ * rvt_alloc_rq - allocate memory for user or kernel buffer
+ * @rq: receive queue data structure
+ * @size: number of request queue entries
+ * @node: The NUMA node
+ * @udata: True if user data is available or not false
+ *
+ * Return: If memory allocation failed, return -ENONEM
+ * This function is used by both shared receive
+ * queues and non-shared receive queues to allocate
+ * memory.
+ */
+int rvt_alloc_rq(struct rvt_rq *rq, u32 size, int node,
+		 struct ib_udata *udata)
+{
+	if (udata) {
+		rq->wq = vmalloc_user(sizeof(struct rvt_rwq) + size);
+		if (!rq->wq)
+			goto bail;
+		/* need kwq with no buffers */
+		rq->kwq = kzalloc_node(sizeof(*rq->kwq), GFP_KERNEL, node);
+		if (!rq->kwq)
+			goto bail;
+		rq->kwq->curr_wq = rq->wq->wq;
+	} else {
+		/* need kwq with buffers */
+		rq->kwq =
+			vzalloc_node(sizeof(struct rvt_krwq) + size, node);
+		if (!rq->kwq)
+			goto bail;
+		rq->kwq->curr_wq = rq->kwq->wq;
+	}
+
+	spin_lock_init(&rq->kwq->p_lock);
+	spin_lock_init(&rq->kwq->c_lock);
+	return 0;
+bail:
+	rvt_free_rq(rq);
+	return -ENOMEM;
+}
+
+/**
+ * rvt_init_qp - initialize the QP state to the reset state
+ * @rdi: rvt dev struct
+ * @qp: the QP to init or reinit
+ * @type: the QP type
+ *
+ * This function is called from both rvt_create_qp() and
+ * rvt_reset_qp().   The difference is that the reset
+ * patch the necessary locks to protect against concurent
+ * access.
+ */
+static void rvt_init_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp,
+			enum ib_qp_type type)
+{
+	qp->remote_qpn = 0;
+	qp->qkey = 0;
+	qp->qp_access_flags = 0;
+	qp->s_flags &= RVT_S_SIGNAL_REQ_WR;
+	qp->s_hdrwords = 0;
+	qp->s_wqe = NULL;
+	qp->s_draining = 0;
+	qp->s_next_psn = 0;
+	qp->s_last_psn = 0;
+	qp->s_sending_psn = 0;
+	qp->s_sending_hpsn = 0;
+	qp->s_psn = 0;
+	qp->r_psn = 0;
+	qp->r_msn = 0;
+	if (type == IB_QPT_RC) {
+		qp->s_state = IB_OPCODE_RC_SEND_LAST;
+		qp->r_state = IB_OPCODE_RC_SEND_LAST;
+	} else {
+		qp->s_state = IB_OPCODE_UC_SEND_LAST;
+		qp->r_state = IB_OPCODE_UC_SEND_LAST;
+	}
+	qp->s_ack_state = IB_OPCODE_RC_ACKNOWLEDGE;
+	qp->r_nak_state = 0;
+	qp->r_aflags = 0;
+	qp->r_flags = 0;
+	qp->s_head = 0;
+	qp->s_tail = 0;
+	qp->s_cur = 0;
+	qp->s_acked = 0;
+	qp->s_last = 0;
+	qp->s_ssn = 1;
+	qp->s_lsn = 0;
+	qp->s_mig_state = IB_MIG_MIGRATED;
+	qp->r_head_ack_queue = 0;
+	qp->s_tail_ack_queue = 0;
+	qp->s_acked_ack_queue = 0;
+	qp->s_num_rd_atomic = 0;
+	qp->r_sge.num_sge = 0;
+	atomic_set(&qp->s_reserved_used, 0);
+}
+
+/**
+ * _rvt_reset_qp - initialize the QP state to the reset state
+ * @rdi: rvt dev struct
+ * @qp: the QP to reset
+ * @type: the QP type
+ *
+ * r_lock, s_hlock, and s_lock are required to be held by the caller
+ */
+static void _rvt_reset_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp,
+			  enum ib_qp_type type)
+	__must_hold(&qp->s_lock)
+	__must_hold(&qp->s_hlock)
+	__must_hold(&qp->r_lock)
+{
+	lockdep_assert_held(&qp->r_lock);
+	lockdep_assert_held(&qp->s_hlock);
+	lockdep_assert_held(&qp->s_lock);
+	if (qp->state != IB_QPS_RESET) {
+		qp->state = IB_QPS_RESET;
+
+		/* Let drivers flush their waitlist */
+		rdi->driver_f.flush_qp_waiters(qp);
+		rvt_stop_rc_timers(qp);
+		qp->s_flags &= ~(RVT_S_TIMER | RVT_S_ANY_WAIT);
+		spin_unlock(&qp->s_lock);
+		spin_unlock(&qp->s_hlock);
+		spin_unlock_irq(&qp->r_lock);
+
+		/* Stop the send queue and the retry timer */
+		rdi->driver_f.stop_send_queue(qp);
+		rvt_del_timers_sync(qp);
+		/* Wait for things to stop */
+		rdi->driver_f.quiesce_qp(qp);
+
+		/* take qp out the hash and wait for it to be unused */
+		rvt_remove_qp(rdi, qp);
+
+		/* grab the lock b/c it was locked at call time */
+		spin_lock_irq(&qp->r_lock);
+		spin_lock(&qp->s_hlock);
+		spin_lock(&qp->s_lock);
+
+		rvt_clear_mr_refs(qp, 1);
+		/*
+		 * Let the driver do any tear down or re-init it needs to for
+		 * a qp that has been reset
+		 */
+		rdi->driver_f.notify_qp_reset(qp);
+	}
+	rvt_init_qp(rdi, qp, type);
+	lockdep_assert_held(&qp->r_lock);
+	lockdep_assert_held(&qp->s_hlock);
+	lockdep_assert_held(&qp->s_lock);
+}
+
+/**
+ * rvt_reset_qp - initialize the QP state to the reset state
+ * @rdi: the device info
+ * @qp: the QP to reset
+ * @type: the QP type
+ *
+ * This is the wrapper function to acquire the r_lock, s_hlock, and s_lock
+ * before calling _rvt_reset_qp().
+ */
+static void rvt_reset_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp,
+			 enum ib_qp_type type)
+{
+	spin_lock_irq(&qp->r_lock);
+	spin_lock(&qp->s_hlock);
+	spin_lock(&qp->s_lock);
+	_rvt_reset_qp(rdi, qp, type);
+	spin_unlock(&qp->s_lock);
+	spin_unlock(&qp->s_hlock);
+	spin_unlock_irq(&qp->r_lock);
+}
+
+/**
+ * rvt_free_qpn - Free a qpn from the bit map
+ * @qpt: QP table
+ * @qpn: queue pair number to free
+ */
+static void rvt_free_qpn(struct rvt_qpn_table *qpt, u32 qpn)
+{
+	struct rvt_qpn_map *map;
+
+	if ((qpn & RVT_AIP_QP_PREFIX_MASK) == RVT_AIP_QP_BASE)
+		qpn &= RVT_AIP_QP_SUFFIX;
+
+	map = qpt->map + (qpn & RVT_QPN_MASK) / RVT_BITS_PER_PAGE;
+	if (map->page)
+		clear_bit(qpn & RVT_BITS_PER_PAGE_MASK, map->page);
+}
+
+/**
+ * get_allowed_ops - Given a QP type return the appropriate allowed OP
+ * @type: valid, supported, QP type
+ */
+static u8 get_allowed_ops(enum ib_qp_type type)
+{
+	return type == IB_QPT_RC ? IB_OPCODE_RC : type == IB_QPT_UC ?
+		IB_OPCODE_UC : IB_OPCODE_UD;
+}
+
+/**
+ * free_ud_wq_attr - Clean up AH attribute cache for UD QPs
+ * @qp: Valid QP with allowed_ops set
+ *
+ * The rvt_swqe data structure being used is a union, so this is
+ * only valid for UD QPs.
+ */
+static void free_ud_wq_attr(struct rvt_qp *qp)
+{
+	struct rvt_swqe *wqe;
+	int i;
+
+	for (i = 0; qp->allowed_ops == IB_OPCODE_UD && i < qp->s_size; i++) {
+		wqe = rvt_get_swqe_ptr(qp, i);
+		kfree(wqe->ud_wr.attr);
+		wqe->ud_wr.attr = NULL;
+	}
+}
+
+/**
+ * alloc_ud_wq_attr - AH attribute cache for UD QPs
+ * @qp: Valid QP with allowed_ops set
+ * @node: Numa node for allocation
+ *
+ * The rvt_swqe data structure being used is a union, so this is
+ * only valid for UD QPs.
+ */
+static int alloc_ud_wq_attr(struct rvt_qp *qp, int node)
+{
+	struct rvt_swqe *wqe;
+	int i;
+
+	for (i = 0; qp->allowed_ops == IB_OPCODE_UD && i < qp->s_size; i++) {
+		wqe = rvt_get_swqe_ptr(qp, i);
+		wqe->ud_wr.attr = kzalloc_node(sizeof(*wqe->ud_wr.attr),
+					       GFP_KERNEL, node);
+		if (!wqe->ud_wr.attr) {
+			free_ud_wq_attr(qp);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * rvt_create_qp - create a queue pair for a device
+ * @ibqp: the queue pair
+ * @init_attr: the attributes of the queue pair
+ * @udata: user data for libibverbs.so
+ *
+ * Queue pair creation is mostly an rvt issue. However, drivers have their own
+ * unique idea of what queue pair numbers mean. For instance there is a reserved
+ * range for PSM.
+ *
+ * Return: 0 on success, otherwise returns an errno.
+ *
+ * Called by the ib_create_qp() core verbs function.
+ */
+int rvt_create_qp(struct ib_qp *ibqp, struct ib_qp_init_attr *init_attr,
+		  struct ib_udata *udata)
+{
+	struct rvt_qp *qp = ibqp_to_rvtqp(ibqp);
+	int ret = -ENOMEM;
+	struct rvt_swqe *swq = NULL;
+	size_t sz;
+	size_t sg_list_sz = 0;
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+	void *priv = NULL;
+	size_t sqsize;
+	u8 exclude_prefix = 0;
+
+	if (!rdi)
+		return -EINVAL;
+
+	if (init_attr->create_flags & ~IB_QP_CREATE_NETDEV_USE)
+		return -EOPNOTSUPP;
+
+	if (init_attr->cap.max_send_sge > rdi->dparms.props.max_send_sge ||
+	    init_attr->cap.max_send_wr > rdi->dparms.props.max_qp_wr)
+		return -EINVAL;
+
+	/* Check receive queue parameters if no SRQ is specified. */
+	if (!init_attr->srq) {
+		if (init_attr->cap.max_recv_sge >
+		    rdi->dparms.props.max_recv_sge ||
+		    init_attr->cap.max_recv_wr > rdi->dparms.props.max_qp_wr)
+			return -EINVAL;
+
+		if (init_attr->cap.max_send_sge +
+		    init_attr->cap.max_send_wr +
+		    init_attr->cap.max_recv_sge +
+		    init_attr->cap.max_recv_wr == 0)
+			return -EINVAL;
+	}
+	sqsize =
+		init_attr->cap.max_send_wr + 1 +
+		rdi->dparms.reserved_operations;
+	switch (init_attr->qp_type) {
+	case IB_QPT_SMI:
+	case IB_QPT_GSI:
+		if (init_attr->port_num == 0 ||
+		    init_attr->port_num > ibqp->device->phys_port_cnt)
+			return -EINVAL;
+		fallthrough;
+	case IB_QPT_UC:
+	case IB_QPT_RC:
+	case IB_QPT_UD:
+		sz = struct_size(swq, sg_list, init_attr->cap.max_send_sge);
+		swq = vzalloc_node(array_size(sz, sqsize), rdi->dparms.node);
+		if (!swq)
+			return -ENOMEM;
+
+		if (init_attr->srq) {
+			struct rvt_srq *srq = ibsrq_to_rvtsrq(init_attr->srq);
+
+			if (srq->rq.max_sge > 1)
+				sg_list_sz = sizeof(*qp->r_sg_list) *
+					(srq->rq.max_sge - 1);
+		} else if (init_attr->cap.max_recv_sge > 1)
+			sg_list_sz = sizeof(*qp->r_sg_list) *
+				(init_attr->cap.max_recv_sge - 1);
+		qp->r_sg_list =
+			kzalloc_node(sg_list_sz, GFP_KERNEL, rdi->dparms.node);
+		if (!qp->r_sg_list)
+			goto bail_qp;
+		qp->allowed_ops = get_allowed_ops(init_attr->qp_type);
+
+		RCU_INIT_POINTER(qp->next, NULL);
+		if (init_attr->qp_type == IB_QPT_RC) {
+			qp->s_ack_queue =
+				kcalloc_node(rvt_max_atomic(rdi),
+					     sizeof(*qp->s_ack_queue),
+					     GFP_KERNEL,
+					     rdi->dparms.node);
+			if (!qp->s_ack_queue)
+				goto bail_qp;
+		}
+		/* initialize timers needed for rc qp */
+		timer_setup(&qp->s_timer, rvt_rc_timeout, 0);
+		hrtimer_init(&qp->s_rnr_timer, CLOCK_MONOTONIC,
+			     HRTIMER_MODE_REL);
+		qp->s_rnr_timer.function = rvt_rc_rnr_retry;
+
+		/*
+		 * Driver needs to set up it's private QP structure and do any
+		 * initialization that is needed.
+		 */
+		priv = rdi->driver_f.qp_priv_alloc(rdi, qp);
+		if (IS_ERR(priv)) {
+			ret = PTR_ERR(priv);
+			goto bail_qp;
+		}
+		qp->priv = priv;
+		qp->timeout_jiffies =
+			usecs_to_jiffies((4096UL * (1UL << qp->timeout)) /
+				1000UL);
+		if (init_attr->srq) {
+			sz = 0;
+		} else {
+			qp->r_rq.size = init_attr->cap.max_recv_wr + 1;
+			qp->r_rq.max_sge = init_attr->cap.max_recv_sge;
+			sz = (sizeof(struct ib_sge) * qp->r_rq.max_sge) +
+				sizeof(struct rvt_rwqe);
+			ret = rvt_alloc_rq(&qp->r_rq, qp->r_rq.size * sz,
+					   rdi->dparms.node, udata);
+			if (ret)
+				goto bail_driver_priv;
+		}
+
+		/*
+		 * ib_create_qp() will initialize qp->ibqp
+		 * except for qp->ibqp.qp_num.
+		 */
+		spin_lock_init(&qp->r_lock);
+		spin_lock_init(&qp->s_hlock);
+		spin_lock_init(&qp->s_lock);
+		atomic_set(&qp->refcount, 0);
+		atomic_set(&qp->local_ops_pending, 0);
+		init_waitqueue_head(&qp->wait);
+		INIT_LIST_HEAD(&qp->rspwait);
+		qp->state = IB_QPS_RESET;
+		qp->s_wq = swq;
+		qp->s_size = sqsize;
+		qp->s_avail = init_attr->cap.max_send_wr;
+		qp->s_max_sge = init_attr->cap.max_send_sge;
+		if (init_attr->sq_sig_type == IB_SIGNAL_REQ_WR)
+			qp->s_flags = RVT_S_SIGNAL_REQ_WR;
+		ret = alloc_ud_wq_attr(qp, rdi->dparms.node);
+		if (ret)
+			goto bail_rq_rvt;
+
+		if (init_attr->create_flags & IB_QP_CREATE_NETDEV_USE)
+			exclude_prefix = RVT_AIP_QP_PREFIX;
+
+		ret = alloc_qpn(rdi, &rdi->qp_dev->qpn_table,
+				init_attr->qp_type,
+				init_attr->port_num,
+				exclude_prefix);
+		if (ret < 0)
+			goto bail_rq_wq;
+
+		qp->ibqp.qp_num = ret;
+		if (init_attr->create_flags & IB_QP_CREATE_NETDEV_USE)
+			qp->ibqp.qp_num |= RVT_AIP_QP_BASE;
+		qp->port_num = init_attr->port_num;
+		rvt_init_qp(rdi, qp, init_attr->qp_type);
+		if (rdi->driver_f.qp_priv_init) {
+			ret = rdi->driver_f.qp_priv_init(rdi, qp, init_attr);
+			if (ret)
+				goto bail_rq_wq;
+		}
+		break;
+
+	default:
+		/* Don't support raw QPs */
+		return -EOPNOTSUPP;
+	}
+
+	init_attr->cap.max_inline_data = 0;
+
+	/*
+	 * Return the address of the RWQ as the offset to mmap.
+	 * See rvt_mmap() for details.
+	 */
+	if (udata && udata->outlen >= sizeof(__u64)) {
+		if (!qp->r_rq.wq) {
+			__u64 offset = 0;
+
+			ret = ib_copy_to_udata(udata, &offset,
+					       sizeof(offset));
+			if (ret)
+				goto bail_qpn;
+		} else {
+			u32 s = sizeof(struct rvt_rwq) + qp->r_rq.size * sz;
+
+			qp->ip = rvt_create_mmap_info(rdi, s, udata,
+						      qp->r_rq.wq);
+			if (IS_ERR(qp->ip)) {
+				ret = PTR_ERR(qp->ip);
+				goto bail_qpn;
+			}
+
+			ret = ib_copy_to_udata(udata, &qp->ip->offset,
+					       sizeof(qp->ip->offset));
+			if (ret)
+				goto bail_ip;
+		}
+		qp->pid = current->pid;
+	}
+
+	spin_lock(&rdi->n_qps_lock);
+	if (rdi->n_qps_allocated == rdi->dparms.props.max_qp) {
+		spin_unlock(&rdi->n_qps_lock);
+		ret = -ENOMEM;
+		goto bail_ip;
+	}
+
+	rdi->n_qps_allocated++;
+	/*
+	 * Maintain a busy_jiffies variable that will be added to the timeout
+	 * period in mod_retry_timer and add_retry_timer. This busy jiffies
+	 * is scaled by the number of rc qps created for the device to reduce
+	 * the number of timeouts occurring when there is a large number of
+	 * qps. busy_jiffies is incremented every rc qp scaling interval.
+	 * The scaling interval is selected based on extensive performance
+	 * evaluation of targeted workloads.
+	 */
+	if (init_attr->qp_type == IB_QPT_RC) {
+		rdi->n_rc_qps++;
+		rdi->busy_jiffies = rdi->n_rc_qps / RC_QP_SCALING_INTERVAL;
+	}
+	spin_unlock(&rdi->n_qps_lock);
+
+	if (qp->ip) {
+		spin_lock_irq(&rdi->pending_lock);
+		list_add(&qp->ip->pending_mmaps, &rdi->pending_mmaps);
+		spin_unlock_irq(&rdi->pending_lock);
+	}
+
+	return 0;
+
+bail_ip:
+	if (qp->ip)
+		kref_put(&qp->ip->ref, rvt_release_mmap_info);
+
+bail_qpn:
+	rvt_free_qpn(&rdi->qp_dev->qpn_table, qp->ibqp.qp_num);
+
+bail_rq_wq:
+	free_ud_wq_attr(qp);
+
+bail_rq_rvt:
+	rvt_free_rq(&qp->r_rq);
+
+bail_driver_priv:
+	rdi->driver_f.qp_priv_free(rdi, qp);
+
+bail_qp:
+	kfree(qp->s_ack_queue);
+	kfree(qp->r_sg_list);
+	vfree(swq);
+	return ret;
+}
+
+/**
+ * rvt_error_qp - put a QP into the error state
+ * @qp: the QP to put into the error state
+ * @err: the receive completion error to signal if a RWQE is active
+ *
+ * Flushes both send and receive work queues.
+ *
+ * Return: true if last WQE event should be generated.
+ * The QP r_lock and s_lock should be held and interrupts disabled.
+ * If we are already in error state, just return.
+ */
+int rvt_error_qp(struct rvt_qp *qp, enum ib_wc_status err)
+{
+	struct ib_wc wc;
+	int ret = 0;
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+
+	lockdep_assert_held(&qp->r_lock);
+	lockdep_assert_held(&qp->s_lock);
+	if (qp->state == IB_QPS_ERR || qp->state == IB_QPS_RESET)
+		goto bail;
+
+	qp->state = IB_QPS_ERR;
+
+	if (qp->s_flags & (RVT_S_TIMER | RVT_S_WAIT_RNR)) {
+		qp->s_flags &= ~(RVT_S_TIMER | RVT_S_WAIT_RNR);
+		del_timer(&qp->s_timer);
+	}
+
+	if (qp->s_flags & RVT_S_ANY_WAIT_SEND)
+		qp->s_flags &= ~RVT_S_ANY_WAIT_SEND;
+
+	rdi->driver_f.notify_error_qp(qp);
+
+	/* Schedule the sending tasklet to drain the send work queue. */
+	if (READ_ONCE(qp->s_last) != qp->s_head)
+		rdi->driver_f.schedule_send(qp);
+
+	rvt_clear_mr_refs(qp, 0);
+
+	memset(&wc, 0, sizeof(wc));
+	wc.qp = &qp->ibqp;
+	wc.opcode = IB_WC_RECV;
+
+	if (test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags)) {
+		wc.wr_id = qp->r_wr_id;
+		wc.status = err;
+		rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc, 1);
+	}
+	wc.status = IB_WC_WR_FLUSH_ERR;
+
+	if (qp->r_rq.kwq) {
+		u32 head;
+		u32 tail;
+		struct rvt_rwq *wq = NULL;
+		struct rvt_krwq *kwq = NULL;
+
+		spin_lock(&qp->r_rq.kwq->c_lock);
+		/* qp->ip used to validate if there is a  user buffer mmaped */
+		if (qp->ip) {
+			wq = qp->r_rq.wq;
+			head = RDMA_READ_UAPI_ATOMIC(wq->head);
+			tail = RDMA_READ_UAPI_ATOMIC(wq->tail);
+		} else {
+			kwq = qp->r_rq.kwq;
+			head = kwq->head;
+			tail = kwq->tail;
+		}
+		/* sanity check pointers before trusting them */
+		if (head >= qp->r_rq.size)
+			head = 0;
+		if (tail >= qp->r_rq.size)
+			tail = 0;
+		while (tail != head) {
+			wc.wr_id = rvt_get_rwqe_ptr(&qp->r_rq, tail)->wr_id;
+			if (++tail >= qp->r_rq.size)
+				tail = 0;
+			rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc, 1);
+		}
+		if (qp->ip)
+			RDMA_WRITE_UAPI_ATOMIC(wq->tail, tail);
+		else
+			kwq->tail = tail;
+		spin_unlock(&qp->r_rq.kwq->c_lock);
+	} else if (qp->ibqp.event_handler) {
+		ret = 1;
+	}
+
+bail:
+	return ret;
+}
+EXPORT_SYMBOL(rvt_error_qp);
+
+/*
+ * Put the QP into the hash table.
+ * The hash table holds a reference to the QP.
+ */
+static void rvt_insert_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp)
+{
+	struct rvt_ibport *rvp = rdi->ports[qp->port_num - 1];
+	unsigned long flags;
+
+	rvt_get_qp(qp);
+	spin_lock_irqsave(&rdi->qp_dev->qpt_lock, flags);
+
+	if (qp->ibqp.qp_num <= 1) {
+		rcu_assign_pointer(rvp->qp[qp->ibqp.qp_num], qp);
+	} else {
+		u32 n = hash_32(qp->ibqp.qp_num, rdi->qp_dev->qp_table_bits);
+
+		qp->next = rdi->qp_dev->qp_table[n];
+		rcu_assign_pointer(rdi->qp_dev->qp_table[n], qp);
+		trace_rvt_qpinsert(qp, n);
+	}
+
+	spin_unlock_irqrestore(&rdi->qp_dev->qpt_lock, flags);
+}
+
+/**
+ * rvt_modify_qp - modify the attributes of a queue pair
+ * @ibqp: the queue pair who's attributes we're modifying
+ * @attr: the new attributes
+ * @attr_mask: the mask of attributes to modify
+ * @udata: user data for libibverbs.so
+ *
+ * Return: 0 on success, otherwise returns an errno.
+ */
+int rvt_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
+		  int attr_mask, struct ib_udata *udata)
+{
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+	struct rvt_qp *qp = ibqp_to_rvtqp(ibqp);
+	enum ib_qp_state cur_state, new_state;
+	struct ib_event ev;
+	int lastwqe = 0;
+	int mig = 0;
+	int pmtu = 0; /* for gcc warning only */
+	int opa_ah;
+
+	if (attr_mask & ~IB_QP_ATTR_STANDARD_BITS)
+		return -EOPNOTSUPP;
+
+	spin_lock_irq(&qp->r_lock);
+	spin_lock(&qp->s_hlock);
+	spin_lock(&qp->s_lock);
+
+	cur_state = attr_mask & IB_QP_CUR_STATE ?
+		attr->cur_qp_state : qp->state;
+	new_state = attr_mask & IB_QP_STATE ? attr->qp_state : cur_state;
+	opa_ah = rdma_cap_opa_ah(ibqp->device, qp->port_num);
+
+	if (!ib_modify_qp_is_ok(cur_state, new_state, ibqp->qp_type,
+				attr_mask))
+		goto inval;
+
+	if (rdi->driver_f.check_modify_qp &&
+	    rdi->driver_f.check_modify_qp(qp, attr, attr_mask, udata))
+		goto inval;
+
+	if (attr_mask & IB_QP_AV) {
+		if (opa_ah) {
+			if (rdma_ah_get_dlid(&attr->ah_attr) >=
+				opa_get_mcast_base(OPA_MCAST_NR))
+				goto inval;
+		} else {
+			if (rdma_ah_get_dlid(&attr->ah_attr) >=
+				be16_to_cpu(IB_MULTICAST_LID_BASE))
+				goto inval;
+		}
+
+		if (rvt_check_ah(qp->ibqp.device, &attr->ah_attr))
+			goto inval;
+	}
+
+	if (attr_mask & IB_QP_ALT_PATH) {
+		if (opa_ah) {
+			if (rdma_ah_get_dlid(&attr->alt_ah_attr) >=
+				opa_get_mcast_base(OPA_MCAST_NR))
+				goto inval;
+		} else {
+			if (rdma_ah_get_dlid(&attr->alt_ah_attr) >=
+				be16_to_cpu(IB_MULTICAST_LID_BASE))
+				goto inval;
+		}
+
+		if (rvt_check_ah(qp->ibqp.device, &attr->alt_ah_attr))
+			goto inval;
+		if (attr->alt_pkey_index >= rvt_get_npkeys(rdi))
+			goto inval;
+	}
+
+	if (attr_mask & IB_QP_PKEY_INDEX)
+		if (attr->pkey_index >= rvt_get_npkeys(rdi))
+			goto inval;
+
+	if (attr_mask & IB_QP_MIN_RNR_TIMER)
+		if (attr->min_rnr_timer > 31)
+			goto inval;
+
+	if (attr_mask & IB_QP_PORT)
+		if (qp->ibqp.qp_type == IB_QPT_SMI ||
+		    qp->ibqp.qp_type == IB_QPT_GSI ||
+		    attr->port_num == 0 ||
+		    attr->port_num > ibqp->device->phys_port_cnt)
+			goto inval;
+
+	if (attr_mask & IB_QP_DEST_QPN)
+		if (attr->dest_qp_num > RVT_QPN_MASK)
+			goto inval;
+
+	if (attr_mask & IB_QP_RETRY_CNT)
+		if (attr->retry_cnt > 7)
+			goto inval;
+
+	if (attr_mask & IB_QP_RNR_RETRY)
+		if (attr->rnr_retry > 7)
+			goto inval;
+
+	/*
+	 * Don't allow invalid path_mtu values.  OK to set greater
+	 * than the active mtu (or even the max_cap, if we have tuned
+	 * that to a small mtu.  We'll set qp->path_mtu
+	 * to the lesser of requested attribute mtu and active,
+	 * for packetizing messages.
+	 * Note that the QP port has to be set in INIT and MTU in RTR.
+	 */
+	if (attr_mask & IB_QP_PATH_MTU) {
+		pmtu = rdi->driver_f.get_pmtu_from_attr(rdi, qp, attr);
+		if (pmtu < 0)
+			goto inval;
+	}
+
+	if (attr_mask & IB_QP_PATH_MIG_STATE) {
+		if (attr->path_mig_state == IB_MIG_REARM) {
+			if (qp->s_mig_state == IB_MIG_ARMED)
+				goto inval;
+			if (new_state != IB_QPS_RTS)
+				goto inval;
+		} else if (attr->path_mig_state == IB_MIG_MIGRATED) {
+			if (qp->s_mig_state == IB_MIG_REARM)
+				goto inval;
+			if (new_state != IB_QPS_RTS && new_state != IB_QPS_SQD)
+				goto inval;
+			if (qp->s_mig_state == IB_MIG_ARMED)
+				mig = 1;
+		} else {
+			goto inval;
+		}
+	}
+
+	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
+		if (attr->max_dest_rd_atomic > rdi->dparms.max_rdma_atomic)
+			goto inval;
+
+	switch (new_state) {
+	case IB_QPS_RESET:
+		if (qp->state != IB_QPS_RESET)
+			_rvt_reset_qp(rdi, qp, ibqp->qp_type);
+		break;
+
+	case IB_QPS_RTR:
+		/* Allow event to re-trigger if QP set to RTR more than once */
+		qp->r_flags &= ~RVT_R_COMM_EST;
+		qp->state = new_state;
+		break;
+
+	case IB_QPS_SQD:
+		qp->s_draining = qp->s_last != qp->s_cur;
+		qp->state = new_state;
+		break;
+
+	case IB_QPS_SQE:
+		if (qp->ibqp.qp_type == IB_QPT_RC)
+			goto inval;
+		qp->state = new_state;
+		break;
+
+	case IB_QPS_ERR:
+		lastwqe = rvt_error_qp(qp, IB_WC_WR_FLUSH_ERR);
+		break;
+
+	default:
+		qp->state = new_state;
+		break;
+	}
+
+	if (attr_mask & IB_QP_PKEY_INDEX)
+		qp->s_pkey_index = attr->pkey_index;
+
+	if (attr_mask & IB_QP_PORT)
+		qp->port_num = attr->port_num;
+
+	if (attr_mask & IB_QP_DEST_QPN)
+		qp->remote_qpn = attr->dest_qp_num;
+
+	if (attr_mask & IB_QP_SQ_PSN) {
+		qp->s_next_psn = attr->sq_psn & rdi->dparms.psn_modify_mask;
+		qp->s_psn = qp->s_next_psn;
+		qp->s_sending_psn = qp->s_next_psn;
+		qp->s_last_psn = qp->s_next_psn - 1;
+		qp->s_sending_hpsn = qp->s_last_psn;
+	}
+
+	if (attr_mask & IB_QP_RQ_PSN)
+		qp->r_psn = attr->rq_psn & rdi->dparms.psn_modify_mask;
+
+	if (attr_mask & IB_QP_ACCESS_FLAGS)
+		qp->qp_access_flags = attr->qp_access_flags;
+
+	if (attr_mask & IB_QP_AV) {
+		rdma_replace_ah_attr(&qp->remote_ah_attr, &attr->ah_attr);
+		qp->s_srate = rdma_ah_get_static_rate(&attr->ah_attr);
+		qp->srate_mbps = ib_rate_to_mbps(qp->s_srate);
+	}
+
+	if (attr_mask & IB_QP_ALT_PATH) {
+		rdma_replace_ah_attr(&qp->alt_ah_attr, &attr->alt_ah_attr);
+		qp->s_alt_pkey_index = attr->alt_pkey_index;
+	}
+
+	if (attr_mask & IB_QP_PATH_MIG_STATE) {
+		qp->s_mig_state = attr->path_mig_state;
+		if (mig) {
+			qp->remote_ah_attr = qp->alt_ah_attr;
+			qp->port_num = rdma_ah_get_port_num(&qp->alt_ah_attr);
+			qp->s_pkey_index = qp->s_alt_pkey_index;
+		}
+	}
+
+	if (attr_mask & IB_QP_PATH_MTU) {
+		qp->pmtu = rdi->driver_f.mtu_from_qp(rdi, qp, pmtu);
+		qp->log_pmtu = ilog2(qp->pmtu);
+	}
+
+	if (attr_mask & IB_QP_RETRY_CNT) {
+		qp->s_retry_cnt = attr->retry_cnt;
+		qp->s_retry = attr->retry_cnt;
+	}
+
+	if (attr_mask & IB_QP_RNR_RETRY) {
+		qp->s_rnr_retry_cnt = attr->rnr_retry;
+		qp->s_rnr_retry = attr->rnr_retry;
+	}
+
+	if (attr_mask & IB_QP_MIN_RNR_TIMER)
+		qp->r_min_rnr_timer = attr->min_rnr_timer;
+
+	if (attr_mask & IB_QP_TIMEOUT) {
+		qp->timeout = attr->timeout;
+		qp->timeout_jiffies = rvt_timeout_to_jiffies(qp->timeout);
+	}
+
+	if (attr_mask & IB_QP_QKEY)
+		qp->qkey = attr->qkey;
+
+	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC)
+		qp->r_max_rd_atomic = attr->max_dest_rd_atomic;
+
+	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC)
+		qp->s_max_rd_atomic = attr->max_rd_atomic;
+
+	if (rdi->driver_f.modify_qp)
+		rdi->driver_f.modify_qp(qp, attr, attr_mask, udata);
+
+	spin_unlock(&qp->s_lock);
+	spin_unlock(&qp->s_hlock);
+	spin_unlock_irq(&qp->r_lock);
+
+	if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT)
+		rvt_insert_qp(rdi, qp);
+
+	if (lastwqe) {
+		ev.device = qp->ibqp.device;
+		ev.element.qp = &qp->ibqp;
+		ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
+		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
+	}
+	if (mig) {
+		ev.device = qp->ibqp.device;
+		ev.element.qp = &qp->ibqp;
+		ev.event = IB_EVENT_PATH_MIG;
+		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
+	}
+	return 0;
+
+inval:
+	spin_unlock(&qp->s_lock);
+	spin_unlock(&qp->s_hlock);
+	spin_unlock_irq(&qp->r_lock);
+	return -EINVAL;
+}
+
+/**
+ * rvt_destroy_qp - destroy a queue pair
+ * @ibqp: the queue pair to destroy
+ * @udata: unused by the driver
+ *
+ * Note that this can be called while the QP is actively sending or
+ * receiving!
+ *
+ * Return: 0 on success.
+ */
+int rvt_destroy_qp(struct ib_qp *ibqp, struct ib_udata *udata)
+{
+	struct rvt_qp *qp = ibqp_to_rvtqp(ibqp);
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+
+	rvt_reset_qp(rdi, qp, ibqp->qp_type);
+
+	wait_event(qp->wait, !atomic_read(&qp->refcount));
+	/* qpn is now available for use again */
+	rvt_free_qpn(&rdi->qp_dev->qpn_table, qp->ibqp.qp_num);
+
+	spin_lock(&rdi->n_qps_lock);
+	rdi->n_qps_allocated--;
+	if (qp->ibqp.qp_type == IB_QPT_RC) {
+		rdi->n_rc_qps--;
+		rdi->busy_jiffies = rdi->n_rc_qps / RC_QP_SCALING_INTERVAL;
+	}
+	spin_unlock(&rdi->n_qps_lock);
+
+	if (qp->ip)
+		kref_put(&qp->ip->ref, rvt_release_mmap_info);
+	kvfree(qp->r_rq.kwq);
+	rdi->driver_f.qp_priv_free(rdi, qp);
+	kfree(qp->s_ack_queue);
+	kfree(qp->r_sg_list);
+	rdma_destroy_ah_attr(&qp->remote_ah_attr);
+	rdma_destroy_ah_attr(&qp->alt_ah_attr);
+	free_ud_wq_attr(qp);
+	vfree(qp->s_wq);
+	return 0;
+}
+
+/**
+ * rvt_query_qp - query an ipbq
+ * @ibqp: IB qp to query
+ * @attr: attr struct to fill in
+ * @attr_mask: attr mask ignored
+ * @init_attr: struct to fill in
+ *
+ * Return: always 0
+ */
+int rvt_query_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
+		 int attr_mask, struct ib_qp_init_attr *init_attr)
+{
+	struct rvt_qp *qp = ibqp_to_rvtqp(ibqp);
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+
+	attr->qp_state = qp->state;
+	attr->cur_qp_state = attr->qp_state;
+	attr->path_mtu = rdi->driver_f.mtu_to_path_mtu(qp->pmtu);
+	attr->path_mig_state = qp->s_mig_state;
+	attr->qkey = qp->qkey;
+	attr->rq_psn = qp->r_psn & rdi->dparms.psn_mask;
+	attr->sq_psn = qp->s_next_psn & rdi->dparms.psn_mask;
+	attr->dest_qp_num = qp->remote_qpn;
+	attr->qp_access_flags = qp->qp_access_flags;
+	attr->cap.max_send_wr = qp->s_size - 1 -
+		rdi->dparms.reserved_operations;
+	attr->cap.max_recv_wr = qp->ibqp.srq ? 0 : qp->r_rq.size - 1;
+	attr->cap.max_send_sge = qp->s_max_sge;
+	attr->cap.max_recv_sge = qp->r_rq.max_sge;
+	attr->cap.max_inline_data = 0;
+	attr->ah_attr = qp->remote_ah_attr;
+	attr->alt_ah_attr = qp->alt_ah_attr;
+	attr->pkey_index = qp->s_pkey_index;
+	attr->alt_pkey_index = qp->s_alt_pkey_index;
+	attr->en_sqd_async_notify = 0;
+	attr->sq_draining = qp->s_draining;
+	attr->max_rd_atomic = qp->s_max_rd_atomic;
+	attr->max_dest_rd_atomic = qp->r_max_rd_atomic;
+	attr->min_rnr_timer = qp->r_min_rnr_timer;
+	attr->port_num = qp->port_num;
+	attr->timeout = qp->timeout;
+	attr->retry_cnt = qp->s_retry_cnt;
+	attr->rnr_retry = qp->s_rnr_retry_cnt;
+	attr->alt_port_num =
+		rdma_ah_get_port_num(&qp->alt_ah_attr);
+	attr->alt_timeout = qp->alt_timeout;
+
+	init_attr->event_handler = qp->ibqp.event_handler;
+	init_attr->qp_context = qp->ibqp.qp_context;
+	init_attr->send_cq = qp->ibqp.send_cq;
+	init_attr->recv_cq = qp->ibqp.recv_cq;
+	init_attr->srq = qp->ibqp.srq;
+	init_attr->cap = attr->cap;
+	if (qp->s_flags & RVT_S_SIGNAL_REQ_WR)
+		init_attr->sq_sig_type = IB_SIGNAL_REQ_WR;
+	else
+		init_attr->sq_sig_type = IB_SIGNAL_ALL_WR;
+	init_attr->qp_type = qp->ibqp.qp_type;
+	init_attr->port_num = qp->port_num;
+	return 0;
+}
+
+/**
+ * rvt_post_recv - post a receive on a QP
+ * @ibqp: the QP to post the receive on
+ * @wr: the WR to post
+ * @bad_wr: the first bad WR is put here
+ *
+ * This may be called from interrupt context.
+ *
+ * Return: 0 on success otherwise errno
+ */
+int rvt_post_recv(struct ib_qp *ibqp, const struct ib_recv_wr *wr,
+		  const struct ib_recv_wr **bad_wr)
+{
+	struct rvt_qp *qp = ibqp_to_rvtqp(ibqp);
+	struct rvt_krwq *wq = qp->r_rq.kwq;
+	unsigned long flags;
+	int qp_err_flush = (ib_rvt_state_ops[qp->state] & RVT_FLUSH_RECV) &&
+				!qp->ibqp.srq;
+
+	/* Check that state is OK to post receive. */
+	if (!(ib_rvt_state_ops[qp->state] & RVT_POST_RECV_OK) || !wq) {
+		*bad_wr = wr;
+		return -EINVAL;
+	}
+
+	for (; wr; wr = wr->next) {
+		struct rvt_rwqe *wqe;
+		u32 next;
+		int i;
+
+		if ((unsigned)wr->num_sge > qp->r_rq.max_sge) {
+			*bad_wr = wr;
+			return -EINVAL;
+		}
+
+		spin_lock_irqsave(&qp->r_rq.kwq->p_lock, flags);
+		next = wq->head + 1;
+		if (next >= qp->r_rq.size)
+			next = 0;
+		if (next == READ_ONCE(wq->tail)) {
+			spin_unlock_irqrestore(&qp->r_rq.kwq->p_lock, flags);
+			*bad_wr = wr;
+			return -ENOMEM;
+		}
+		if (unlikely(qp_err_flush)) {
+			struct ib_wc wc;
+
+			memset(&wc, 0, sizeof(wc));
+			wc.qp = &qp->ibqp;
+			wc.opcode = IB_WC_RECV;
+			wc.wr_id = wr->wr_id;
+			wc.status = IB_WC_WR_FLUSH_ERR;
+			rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc, 1);
+		} else {
+			wqe = rvt_get_rwqe_ptr(&qp->r_rq, wq->head);
+			wqe->wr_id = wr->wr_id;
+			wqe->num_sge = wr->num_sge;
+			for (i = 0; i < wr->num_sge; i++) {
+				wqe->sg_list[i].addr = wr->sg_list[i].addr;
+				wqe->sg_list[i].length = wr->sg_list[i].length;
+				wqe->sg_list[i].lkey = wr->sg_list[i].lkey;
+			}
+			/*
+			 * Make sure queue entry is written
+			 * before the head index.
+			 */
+			smp_store_release(&wq->head, next);
+		}
+		spin_unlock_irqrestore(&qp->r_rq.kwq->p_lock, flags);
+	}
+	return 0;
+}
+
+/**
+ * rvt_qp_valid_operation - validate post send wr request
+ * @qp: the qp
+ * @post_parms: the post send table for the driver
+ * @wr: the work request
+ *
+ * The routine validates the operation based on the
+ * validation table an returns the length of the operation
+ * which can extend beyond the ib_send_bw.  Operation
+ * dependent flags key atomic operation validation.
+ *
+ * There is an exception for UD qps that validates the pd and
+ * overrides the length to include the additional UD specific
+ * length.
+ *
+ * Returns a negative error or the length of the work request
+ * for building the swqe.
+ */
+static inline int rvt_qp_valid_operation(
+	struct rvt_qp *qp,
+	const struct rvt_operation_params *post_parms,
+	const struct ib_send_wr *wr)
+{
+	int len;
+
+	if (wr->opcode >= RVT_OPERATION_MAX || !post_parms[wr->opcode].length)
+		return -EINVAL;
+	if (!(post_parms[wr->opcode].qpt_support & BIT(qp->ibqp.qp_type)))
+		return -EINVAL;
+	if ((post_parms[wr->opcode].flags & RVT_OPERATION_PRIV) &&
+	    ibpd_to_rvtpd(qp->ibqp.pd)->user)
+		return -EINVAL;
+	if (post_parms[wr->opcode].flags & RVT_OPERATION_ATOMIC_SGE &&
+	    (wr->num_sge == 0 ||
+	     wr->sg_list[0].length < sizeof(u64) ||
+	     wr->sg_list[0].addr & (sizeof(u64) - 1)))
+		return -EINVAL;
+	if (post_parms[wr->opcode].flags & RVT_OPERATION_ATOMIC &&
+	    !qp->s_max_rd_atomic)
+		return -EINVAL;
+	len = post_parms[wr->opcode].length;
+	/* UD specific */
+	if (qp->ibqp.qp_type != IB_QPT_UC &&
+	    qp->ibqp.qp_type != IB_QPT_RC) {
+		if (qp->ibqp.pd != ud_wr(wr)->ah->pd)
+			return -EINVAL;
+		len = sizeof(struct ib_ud_wr);
+	}
+	return len;
+}
+
+/**
+ * rvt_qp_is_avail - determine queue capacity
+ * @qp: the qp
+ * @rdi: the rdmavt device
+ * @reserved_op: is reserved operation
+ *
+ * This assumes the s_hlock is held but the s_last
+ * qp variable is uncontrolled.
+ *
+ * For non reserved operations, the qp->s_avail
+ * may be changed.
+ *
+ * The return value is zero or a -ENOMEM.
+ */
+static inline int rvt_qp_is_avail(
+	struct rvt_qp *qp,
+	struct rvt_dev_info *rdi,
+	bool reserved_op)
+{
+	u32 slast;
+	u32 avail;
+	u32 reserved_used;
+
+	/* see rvt_qp_wqe_unreserve() */
+	smp_mb__before_atomic();
+	if (unlikely(reserved_op)) {
+		/* see rvt_qp_wqe_unreserve() */
+		reserved_used = atomic_read(&qp->s_reserved_used);
+		if (reserved_used >= rdi->dparms.reserved_operations)
+			return -ENOMEM;
+		return 0;
+	}
+	/* non-reserved operations */
+	if (likely(qp->s_avail))
+		return 0;
+	/* See rvt_qp_complete_swqe() */
+	slast = smp_load_acquire(&qp->s_last);
+	if (qp->s_head >= slast)
+		avail = qp->s_size - (qp->s_head - slast);
+	else
+		avail = slast - qp->s_head;
+
+	reserved_used = atomic_read(&qp->s_reserved_used);
+	avail =  avail - 1 -
+		(rdi->dparms.reserved_operations - reserved_used);
+	/* insure we don't assign a negative s_avail */
+	if ((s32)avail <= 0)
+		return -ENOMEM;
+	qp->s_avail = avail;
+	if (WARN_ON(qp->s_avail >
+		    (qp->s_size - 1 - rdi->dparms.reserved_operations)))
+		rvt_pr_err(rdi,
+			   "More avail entries than QP RB size.\nQP: %u, size: %u, avail: %u\nhead: %u, tail: %u, cur: %u, acked: %u, last: %u",
+			   qp->ibqp.qp_num, qp->s_size, qp->s_avail,
+			   qp->s_head, qp->s_tail, qp->s_cur,
+			   qp->s_acked, qp->s_last);
+	return 0;
+}
+
+/**
+ * rvt_post_one_wr - post one RC, UC, or UD send work request
+ * @qp: the QP to post on
+ * @wr: the work request to send
+ * @call_send: kick the send engine into gear
+ */
+static int rvt_post_one_wr(struct rvt_qp *qp,
+			   const struct ib_send_wr *wr,
+			   bool *call_send)
+{
+	struct rvt_swqe *wqe;
+	u32 next;
+	int i;
+	int j;
+	int acc;
+	struct rvt_lkey_table *rkt;
+	struct rvt_pd *pd;
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+	u8 log_pmtu;
+	int ret;
+	size_t cplen;
+	bool reserved_op;
+	int local_ops_delayed = 0;
+
+	BUILD_BUG_ON(IB_QPT_MAX >= (sizeof(u32) * BITS_PER_BYTE));
+
+	/* IB spec says that num_sge == 0 is OK. */
+	if (unlikely(wr->num_sge > qp->s_max_sge))
+		return -EINVAL;
+
+	ret = rvt_qp_valid_operation(qp, rdi->post_parms, wr);
+	if (ret < 0)
+		return ret;
+	cplen = ret;
+
+	/*
+	 * Local operations include fast register and local invalidate.
+	 * Fast register needs to be processed immediately because the
+	 * registered lkey may be used by following work requests and the
+	 * lkey needs to be valid at the time those requests are posted.
+	 * Local invalidate can be processed immediately if fencing is
+	 * not required and no previous local invalidate ops are pending.
+	 * Signaled local operations that have been processed immediately
+	 * need to have requests with "completion only" flags set posted
+	 * to the send queue in order to generate completions.
+	 */
+	if ((rdi->post_parms[wr->opcode].flags & RVT_OPERATION_LOCAL)) {
+		switch (wr->opcode) {
+		case IB_WR_REG_MR:
+			ret = rvt_fast_reg_mr(qp,
+					      reg_wr(wr)->mr,
+					      reg_wr(wr)->key,
+					      reg_wr(wr)->access);
+			if (ret || !(wr->send_flags & IB_SEND_SIGNALED))
+				return ret;
+			break;
+		case IB_WR_LOCAL_INV:
+			if ((wr->send_flags & IB_SEND_FENCE) ||
+			    atomic_read(&qp->local_ops_pending)) {
+				local_ops_delayed = 1;
+			} else {
+				ret = rvt_invalidate_rkey(
+					qp, wr->ex.invalidate_rkey);
+				if (ret || !(wr->send_flags & IB_SEND_SIGNALED))
+					return ret;
+			}
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	reserved_op = rdi->post_parms[wr->opcode].flags &
+			RVT_OPERATION_USE_RESERVE;
+	/* check for avail */
+	ret = rvt_qp_is_avail(qp, rdi, reserved_op);
+	if (ret)
+		return ret;
+	next = qp->s_head + 1;
+	if (next >= qp->s_size)
+		next = 0;
+
+	rkt = &rdi->lkey_table;
+	pd = ibpd_to_rvtpd(qp->ibqp.pd);
+	wqe = rvt_get_swqe_ptr(qp, qp->s_head);
+
+	/* cplen has length from above */
+	memcpy(&wqe->ud_wr, wr, cplen);
+
+	wqe->length = 0;
+	j = 0;
+	if (wr->num_sge) {
+		struct rvt_sge *last_sge = NULL;
+
+		acc = wr->opcode >= IB_WR_RDMA_READ ?
+			IB_ACCESS_LOCAL_WRITE : 0;
+		for (i = 0; i < wr->num_sge; i++) {
+			u32 length = wr->sg_list[i].length;
+
+			if (length == 0)
+				continue;
+			ret = rvt_lkey_ok(rkt, pd, &wqe->sg_list[j], last_sge,
+					  &wr->sg_list[i], acc);
+			if (unlikely(ret < 0))
+				goto bail_inval_free;
+			wqe->length += length;
+			if (ret)
+				last_sge = &wqe->sg_list[j];
+			j += ret;
+		}
+		wqe->wr.num_sge = j;
+	}
+
+	/*
+	 * Calculate and set SWQE PSN values prior to handing it off
+	 * to the driver's check routine. This give the driver the
+	 * opportunity to adjust PSN values based on internal checks.
+	 */
+	log_pmtu = qp->log_pmtu;
+	if (qp->allowed_ops == IB_OPCODE_UD) {
+		struct rvt_ah *ah = rvt_get_swqe_ah(wqe);
+
+		log_pmtu = ah->log_pmtu;
+		rdma_copy_ah_attr(wqe->ud_wr.attr, &ah->attr);
+	}
+
+	if (rdi->post_parms[wr->opcode].flags & RVT_OPERATION_LOCAL) {
+		if (local_ops_delayed)
+			atomic_inc(&qp->local_ops_pending);
+		else
+			wqe->wr.send_flags |= RVT_SEND_COMPLETION_ONLY;
+		wqe->ssn = 0;
+		wqe->psn = 0;
+		wqe->lpsn = 0;
+	} else {
+		wqe->ssn = qp->s_ssn++;
+		wqe->psn = qp->s_next_psn;
+		wqe->lpsn = wqe->psn +
+				(wqe->length ?
+					((wqe->length - 1) >> log_pmtu) :
+					0);
+	}
+
+	/* general part of wqe valid - allow for driver checks */
+	if (rdi->driver_f.setup_wqe) {
+		ret = rdi->driver_f.setup_wqe(qp, wqe, call_send);
+		if (ret < 0)
+			goto bail_inval_free_ref;
+	}
+
+	if (!(rdi->post_parms[wr->opcode].flags & RVT_OPERATION_LOCAL))
+		qp->s_next_psn = wqe->lpsn + 1;
+
+	if (unlikely(reserved_op)) {
+		wqe->wr.send_flags |= RVT_SEND_RESERVE_USED;
+		rvt_qp_wqe_reserve(qp, wqe);
+	} else {
+		wqe->wr.send_flags &= ~RVT_SEND_RESERVE_USED;
+		qp->s_avail--;
+	}
+	trace_rvt_post_one_wr(qp, wqe, wr->num_sge);
+	smp_wmb(); /* see request builders */
+	qp->s_head = next;
+
+	return 0;
+
+bail_inval_free_ref:
+	if (qp->allowed_ops == IB_OPCODE_UD)
+		rdma_destroy_ah_attr(wqe->ud_wr.attr);
+bail_inval_free:
+	/* release mr holds */
+	while (j) {
+		struct rvt_sge *sge = &wqe->sg_list[--j];
+
+		rvt_put_mr(sge->mr);
+	}
+	return ret;
+}
+
+/**
+ * rvt_post_send - post a send on a QP
+ * @ibqp: the QP to post the send on
+ * @wr: the list of work requests to post
+ * @bad_wr: the first bad WR is put here
+ *
+ * This may be called from interrupt context.
+ *
+ * Return: 0 on success else errno
+ */
+int rvt_post_send(struct ib_qp *ibqp, const struct ib_send_wr *wr,
+		  const struct ib_send_wr **bad_wr)
+{
+	struct rvt_qp *qp = ibqp_to_rvtqp(ibqp);
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+	unsigned long flags = 0;
+	bool call_send;
+	unsigned nreq = 0;
+	int err = 0;
+
+	spin_lock_irqsave(&qp->s_hlock, flags);
+
+	/*
+	 * Ensure QP state is such that we can send. If not bail out early,
+	 * there is no need to do this every time we post a send.
+	 */
+	if (unlikely(!(ib_rvt_state_ops[qp->state] & RVT_POST_SEND_OK))) {
+		spin_unlock_irqrestore(&qp->s_hlock, flags);
+		return -EINVAL;
+	}
+
+	/*
+	 * If the send queue is empty, and we only have a single WR then just go
+	 * ahead and kick the send engine into gear. Otherwise we will always
+	 * just schedule the send to happen later.
+	 */
+	call_send = qp->s_head == READ_ONCE(qp->s_last) && !wr->next;
+
+	for (; wr; wr = wr->next) {
+		err = rvt_post_one_wr(qp, wr, &call_send);
+		if (unlikely(err)) {
+			*bad_wr = wr;
+			goto bail;
+		}
+		nreq++;
+	}
+bail:
+	spin_unlock_irqrestore(&qp->s_hlock, flags);
+	if (nreq) {
+		/*
+		 * Only call do_send if there is exactly one packet, and the
+		 * driver said it was ok.
+		 */
+		if (nreq == 1 && call_send)
+			rdi->driver_f.do_send(qp);
+		else
+			rdi->driver_f.schedule_send_no_lock(qp);
+	}
+	return err;
+}
+
+/**
+ * rvt_post_srq_recv - post a receive on a shared receive queue
+ * @ibsrq: the SRQ to post the receive on
+ * @wr: the list of work requests to post
+ * @bad_wr: A pointer to the first WR to cause a problem is put here
+ *
+ * This may be called from interrupt context.
+ *
+ * Return: 0 on success else errno
+ */
+int rvt_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr,
+		      const struct ib_recv_wr **bad_wr)
+{
+	struct rvt_srq *srq = ibsrq_to_rvtsrq(ibsrq);
+	struct rvt_krwq *wq;
+	unsigned long flags;
+
+	for (; wr; wr = wr->next) {
+		struct rvt_rwqe *wqe;
+		u32 next;
+		int i;
+
+		if ((unsigned)wr->num_sge > srq->rq.max_sge) {
+			*bad_wr = wr;
+			return -EINVAL;
+		}
+
+		spin_lock_irqsave(&srq->rq.kwq->p_lock, flags);
+		wq = srq->rq.kwq;
+		next = wq->head + 1;
+		if (next >= srq->rq.size)
+			next = 0;
+		if (next == READ_ONCE(wq->tail)) {
+			spin_unlock_irqrestore(&srq->rq.kwq->p_lock, flags);
+			*bad_wr = wr;
+			return -ENOMEM;
+		}
+
+		wqe = rvt_get_rwqe_ptr(&srq->rq, wq->head);
+		wqe->wr_id = wr->wr_id;
+		wqe->num_sge = wr->num_sge;
+		for (i = 0; i < wr->num_sge; i++) {
+			wqe->sg_list[i].addr = wr->sg_list[i].addr;
+			wqe->sg_list[i].length = wr->sg_list[i].length;
+			wqe->sg_list[i].lkey = wr->sg_list[i].lkey;
+		}
+		/* Make sure queue entry is written before the head index. */
+		smp_store_release(&wq->head, next);
+		spin_unlock_irqrestore(&srq->rq.kwq->p_lock, flags);
+	}
+	return 0;
+}
+
+/*
+ * rvt used the internal kernel struct as part of its ABI, for now make sure
+ * the kernel struct does not change layout. FIXME: rvt should never cast the
+ * user struct to a kernel struct.
+ */
+static struct ib_sge *rvt_cast_sge(struct rvt_wqe_sge *sge)
+{
+	BUILD_BUG_ON(offsetof(struct ib_sge, addr) !=
+		     offsetof(struct rvt_wqe_sge, addr));
+	BUILD_BUG_ON(offsetof(struct ib_sge, length) !=
+		     offsetof(struct rvt_wqe_sge, length));
+	BUILD_BUG_ON(offsetof(struct ib_sge, lkey) !=
+		     offsetof(struct rvt_wqe_sge, lkey));
+	return (struct ib_sge *)sge;
+}
+
+/*
+ * Validate a RWQE and fill in the SGE state.
+ * Return 1 if OK.
+ */
+static int init_sge(struct rvt_qp *qp, struct rvt_rwqe *wqe)
+{
+	int i, j, ret;
+	struct ib_wc wc;
+	struct rvt_lkey_table *rkt;
+	struct rvt_pd *pd;
+	struct rvt_sge_state *ss;
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+
+	rkt = &rdi->lkey_table;
+	pd = ibpd_to_rvtpd(qp->ibqp.srq ? qp->ibqp.srq->pd : qp->ibqp.pd);
+	ss = &qp->r_sge;
+	ss->sg_list = qp->r_sg_list;
+	qp->r_len = 0;
+	for (i = j = 0; i < wqe->num_sge; i++) {
+		if (wqe->sg_list[i].length == 0)
+			continue;
+		/* Check LKEY */
+		ret = rvt_lkey_ok(rkt, pd, j ? &ss->sg_list[j - 1] : &ss->sge,
+				  NULL, rvt_cast_sge(&wqe->sg_list[i]),
+				  IB_ACCESS_LOCAL_WRITE);
+		if (unlikely(ret <= 0))
+			goto bad_lkey;
+		qp->r_len += wqe->sg_list[i].length;
+		j++;
+	}
+	ss->num_sge = j;
+	ss->total_len = qp->r_len;
+	return 1;
+
+bad_lkey:
+	while (j) {
+		struct rvt_sge *sge = --j ? &ss->sg_list[j - 1] : &ss->sge;
+
+		rvt_put_mr(sge->mr);
+	}
+	ss->num_sge = 0;
+	memset(&wc, 0, sizeof(wc));
+	wc.wr_id = wqe->wr_id;
+	wc.status = IB_WC_LOC_PROT_ERR;
+	wc.opcode = IB_WC_RECV;
+	wc.qp = &qp->ibqp;
+	/* Signal solicited completion event. */
+	rvt_cq_enter(ibcq_to_rvtcq(qp->ibqp.recv_cq), &wc, 1);
+	return 0;
+}
+
+/**
+ * get_rvt_head - get head indices of the circular buffer
+ * @rq: data structure for request queue entry
+ * @ip: the QP
+ *
+ * Return - head index value
+ */
+static inline u32 get_rvt_head(struct rvt_rq *rq, void *ip)
+{
+	u32 head;
+
+	if (ip)
+		head = RDMA_READ_UAPI_ATOMIC(rq->wq->head);
+	else
+		head = rq->kwq->head;
+
+	return head;
+}
+
+/**
+ * rvt_get_rwqe - copy the next RWQE into the QP's RWQE
+ * @qp: the QP
+ * @wr_id_only: update qp->r_wr_id only, not qp->r_sge
+ *
+ * Return -1 if there is a local error, 0 if no RWQE is available,
+ * otherwise return 1.
+ *
+ * Can be called from interrupt level.
+ */
+int rvt_get_rwqe(struct rvt_qp *qp, bool wr_id_only)
+{
+	unsigned long flags;
+	struct rvt_rq *rq;
+	struct rvt_krwq *kwq = NULL;
+	struct rvt_rwq *wq;
+	struct rvt_srq *srq;
+	struct rvt_rwqe *wqe;
+	void (*handler)(struct ib_event *, void *);
+	u32 tail;
+	u32 head;
+	int ret;
+	void *ip = NULL;
+
+	if (qp->ibqp.srq) {
+		srq = ibsrq_to_rvtsrq(qp->ibqp.srq);
+		handler = srq->ibsrq.event_handler;
+		rq = &srq->rq;
+		ip = srq->ip;
+	} else {
+		srq = NULL;
+		handler = NULL;
+		rq = &qp->r_rq;
+		ip = qp->ip;
+	}
+
+	spin_lock_irqsave(&rq->kwq->c_lock, flags);
+	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK)) {
+		ret = 0;
+		goto unlock;
+	}
+	kwq = rq->kwq;
+	if (ip) {
+		wq = rq->wq;
+		tail = RDMA_READ_UAPI_ATOMIC(wq->tail);
+	} else {
+		tail = kwq->tail;
+	}
+
+	/* Validate tail before using it since it is user writable. */
+	if (tail >= rq->size)
+		tail = 0;
+
+	if (kwq->count < RVT_RWQ_COUNT_THRESHOLD) {
+		head = get_rvt_head(rq, ip);
+		kwq->count = rvt_get_rq_count(rq, head, tail);
+	}
+	if (unlikely(kwq->count == 0)) {
+		ret = 0;
+		goto unlock;
+	}
+	/* Make sure entry is read after the count is read. */
+	smp_rmb();
+	wqe = rvt_get_rwqe_ptr(rq, tail);
+	/*
+	 * Even though we update the tail index in memory, the verbs
+	 * consumer is not supposed to post more entries until a
+	 * completion is generated.
+	 */
+	if (++tail >= rq->size)
+		tail = 0;
+	if (ip)
+		RDMA_WRITE_UAPI_ATOMIC(wq->tail, tail);
+	else
+		kwq->tail = tail;
+	if (!wr_id_only && !init_sge(qp, wqe)) {
+		ret = -1;
+		goto unlock;
+	}
+	qp->r_wr_id = wqe->wr_id;
+
+	kwq->count--;
+	ret = 1;
+	set_bit(RVT_R_WRID_VALID, &qp->r_aflags);
+	if (handler) {
+		/*
+		 * Validate head pointer value and compute
+		 * the number of remaining WQEs.
+		 */
+		if (kwq->count < srq->limit) {
+			kwq->count =
+				rvt_get_rq_count(rq,
+						 get_rvt_head(rq, ip), tail);
+			if (kwq->count < srq->limit) {
+				struct ib_event ev;
+
+				srq->limit = 0;
+				spin_unlock_irqrestore(&rq->kwq->c_lock, flags);
+				ev.device = qp->ibqp.device;
+				ev.element.srq = qp->ibqp.srq;
+				ev.event = IB_EVENT_SRQ_LIMIT_REACHED;
+				handler(&ev, srq->ibsrq.srq_context);
+				goto bail;
+			}
+		}
+	}
+unlock:
+	spin_unlock_irqrestore(&rq->kwq->c_lock, flags);
+bail:
+	return ret;
+}
+EXPORT_SYMBOL(rvt_get_rwqe);
+
+/**
+ * rvt_comm_est - handle trap with QP established
+ * @qp: the QP
+ */
+void rvt_comm_est(struct rvt_qp *qp)
+{
+	qp->r_flags |= RVT_R_COMM_EST;
+	if (qp->ibqp.event_handler) {
+		struct ib_event ev;
+
+		ev.device = qp->ibqp.device;
+		ev.element.qp = &qp->ibqp;
+		ev.event = IB_EVENT_COMM_EST;
+		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
+	}
+}
+EXPORT_SYMBOL(rvt_comm_est);
+
+void rvt_rc_error(struct rvt_qp *qp, enum ib_wc_status err)
+{
+	unsigned long flags;
+	int lastwqe;
+
+	spin_lock_irqsave(&qp->s_lock, flags);
+	lastwqe = rvt_error_qp(qp, err);
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+
+	if (lastwqe) {
+		struct ib_event ev;
+
+		ev.device = qp->ibqp.device;
+		ev.element.qp = &qp->ibqp;
+		ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
+		qp->ibqp.event_handler(&ev, qp->ibqp.qp_context);
+	}
+}
+EXPORT_SYMBOL(rvt_rc_error);
+
+/*
+ *  rvt_rnr_tbl_to_usec - return index into ib_rvt_rnr_table
+ *  @index - the index
+ *  return usec from an index into ib_rvt_rnr_table
+ */
+unsigned long rvt_rnr_tbl_to_usec(u32 index)
+{
+	return ib_rvt_rnr_table[(index & IB_AETH_CREDIT_MASK)];
+}
+EXPORT_SYMBOL(rvt_rnr_tbl_to_usec);
+
+static inline unsigned long rvt_aeth_to_usec(u32 aeth)
+{
+	return ib_rvt_rnr_table[(aeth >> IB_AETH_CREDIT_SHIFT) &
+				  IB_AETH_CREDIT_MASK];
+}
+
+/*
+ *  rvt_add_retry_timer_ext - add/start a retry timer
+ *  @qp - the QP
+ *  @shift - timeout shift to wait for multiple packets
+ *  add a retry timer on the QP
+ */
+void rvt_add_retry_timer_ext(struct rvt_qp *qp, u8 shift)
+{
+	struct ib_qp *ibqp = &qp->ibqp;
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+
+	lockdep_assert_held(&qp->s_lock);
+	qp->s_flags |= RVT_S_TIMER;
+       /* 4.096 usec. * (1 << qp->timeout) */
+	qp->s_timer.expires = jiffies + rdi->busy_jiffies +
+			      (qp->timeout_jiffies << shift);
+	add_timer(&qp->s_timer);
+}
+EXPORT_SYMBOL(rvt_add_retry_timer_ext);
+
+/**
+ * rvt_add_rnr_timer - add/start an rnr timer on the QP
+ * @qp: the QP
+ * @aeth: aeth of RNR timeout, simulated aeth for loopback
+ */
+void rvt_add_rnr_timer(struct rvt_qp *qp, u32 aeth)
+{
+	u32 to;
+
+	lockdep_assert_held(&qp->s_lock);
+	qp->s_flags |= RVT_S_WAIT_RNR;
+	to = rvt_aeth_to_usec(aeth);
+	trace_rvt_rnrnak_add(qp, to);
+	hrtimer_start(&qp->s_rnr_timer,
+		      ns_to_ktime(1000 * to), HRTIMER_MODE_REL_PINNED);
+}
+EXPORT_SYMBOL(rvt_add_rnr_timer);
+
+/**
+ * rvt_stop_rc_timers - stop all timers
+ * @qp: the QP
+ * stop any pending timers
+ */
+void rvt_stop_rc_timers(struct rvt_qp *qp)
+{
+	lockdep_assert_held(&qp->s_lock);
+	/* Remove QP from all timers */
+	if (qp->s_flags & (RVT_S_TIMER | RVT_S_WAIT_RNR)) {
+		qp->s_flags &= ~(RVT_S_TIMER | RVT_S_WAIT_RNR);
+		del_timer(&qp->s_timer);
+		hrtimer_try_to_cancel(&qp->s_rnr_timer);
+	}
+}
+EXPORT_SYMBOL(rvt_stop_rc_timers);
+
+/**
+ * rvt_stop_rnr_timer - stop an rnr timer
+ * @qp: the QP
+ *
+ * stop an rnr timer and return if the timer
+ * had been pending.
+ */
+static void rvt_stop_rnr_timer(struct rvt_qp *qp)
+{
+	lockdep_assert_held(&qp->s_lock);
+	/* Remove QP from rnr timer */
+	if (qp->s_flags & RVT_S_WAIT_RNR) {
+		qp->s_flags &= ~RVT_S_WAIT_RNR;
+		trace_rvt_rnrnak_stop(qp, 0);
+	}
+}
+
+/**
+ * rvt_del_timers_sync - wait for any timeout routines to exit
+ * @qp: the QP
+ */
+void rvt_del_timers_sync(struct rvt_qp *qp)
+{
+	del_timer_sync(&qp->s_timer);
+	hrtimer_cancel(&qp->s_rnr_timer);
+}
+EXPORT_SYMBOL(rvt_del_timers_sync);
+
+/*
+ * This is called from s_timer for missing responses.
+ */
+static void rvt_rc_timeout(struct timer_list *t)
+{
+	struct rvt_qp *qp = from_timer(qp, t, s_timer);
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+	unsigned long flags;
+
+	spin_lock_irqsave(&qp->r_lock, flags);
+	spin_lock(&qp->s_lock);
+	if (qp->s_flags & RVT_S_TIMER) {
+		struct rvt_ibport *rvp = rdi->ports[qp->port_num - 1];
+
+		qp->s_flags &= ~RVT_S_TIMER;
+		rvp->n_rc_timeouts++;
+		del_timer(&qp->s_timer);
+		trace_rvt_rc_timeout(qp, qp->s_last_psn + 1);
+		if (rdi->driver_f.notify_restart_rc)
+			rdi->driver_f.notify_restart_rc(qp,
+							qp->s_last_psn + 1,
+							1);
+		rdi->driver_f.schedule_send(qp);
+	}
+	spin_unlock(&qp->s_lock);
+	spin_unlock_irqrestore(&qp->r_lock, flags);
+}
+
+/*
+ * This is called from s_timer for RNR timeouts.
+ */
+enum hrtimer_restart rvt_rc_rnr_retry(struct hrtimer *t)
+{
+	struct rvt_qp *qp = container_of(t, struct rvt_qp, s_rnr_timer);
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+	unsigned long flags;
+
+	spin_lock_irqsave(&qp->s_lock, flags);
+	rvt_stop_rnr_timer(qp);
+	trace_rvt_rnrnak_timeout(qp, 0);
+	rdi->driver_f.schedule_send(qp);
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+	return HRTIMER_NORESTART;
+}
+EXPORT_SYMBOL(rvt_rc_rnr_retry);
+
+/**
+ * rvt_qp_iter_init - initial for QP iteration
+ * @rdi: rvt devinfo
+ * @v: u64 value
+ * @cb: user-defined callback
+ *
+ * This returns an iterator suitable for iterating QPs
+ * in the system.
+ *
+ * The @cb is a user-defined callback and @v is a 64-bit
+ * value passed to and relevant for processing in the
+ * @cb.  An example use case would be to alter QP processing
+ * based on criteria not part of the rvt_qp.
+ *
+ * Use cases that require memory allocation to succeed
+ * must preallocate appropriately.
+ *
+ * Return: a pointer to an rvt_qp_iter or NULL
+ */
+struct rvt_qp_iter *rvt_qp_iter_init(struct rvt_dev_info *rdi,
+				     u64 v,
+				     void (*cb)(struct rvt_qp *qp, u64 v))
+{
+	struct rvt_qp_iter *i;
+
+	i = kzalloc(sizeof(*i), GFP_KERNEL);
+	if (!i)
+		return NULL;
+
+	i->rdi = rdi;
+	/* number of special QPs (SMI/GSI) for device */
+	i->specials = rdi->ibdev.phys_port_cnt * 2;
+	i->v = v;
+	i->cb = cb;
+
+	return i;
+}
+EXPORT_SYMBOL(rvt_qp_iter_init);
+
+/**
+ * rvt_qp_iter_next - return the next QP in iter
+ * @iter: the iterator
+ *
+ * Fine grained QP iterator suitable for use
+ * with debugfs seq_file mechanisms.
+ *
+ * Updates iter->qp with the current QP when the return
+ * value is 0.
+ *
+ * Return: 0 - iter->qp is valid 1 - no more QPs
+ */
+int rvt_qp_iter_next(struct rvt_qp_iter *iter)
+	__must_hold(RCU)
+{
+	int n = iter->n;
+	int ret = 1;
+	struct rvt_qp *pqp = iter->qp;
+	struct rvt_qp *qp;
+	struct rvt_dev_info *rdi = iter->rdi;
+
+	/*
+	 * The approach is to consider the special qps
+	 * as additional table entries before the
+	 * real hash table.  Since the qp code sets
+	 * the qp->next hash link to NULL, this works just fine.
+	 *
+	 * iter->specials is 2 * # ports
+	 *
+	 * n = 0..iter->specials is the special qp indices
+	 *
+	 * n = iter->specials..rdi->qp_dev->qp_table_size+iter->specials are
+	 * the potential hash bucket entries
+	 *
+	 */
+	for (; n <  rdi->qp_dev->qp_table_size + iter->specials; n++) {
+		if (pqp) {
+			qp = rcu_dereference(pqp->next);
+		} else {
+			if (n < iter->specials) {
+				struct rvt_ibport *rvp;
+				int pidx;
+
+				pidx = n % rdi->ibdev.phys_port_cnt;
+				rvp = rdi->ports[pidx];
+				qp = rcu_dereference(rvp->qp[n & 1]);
+			} else {
+				qp = rcu_dereference(
+					rdi->qp_dev->qp_table[
+						(n - iter->specials)]);
+			}
+		}
+		pqp = qp;
+		if (qp) {
+			iter->qp = qp;
+			iter->n = n;
+			return 0;
+		}
+	}
+	return ret;
+}
+EXPORT_SYMBOL(rvt_qp_iter_next);
+
+/**
+ * rvt_qp_iter - iterate all QPs
+ * @rdi: rvt devinfo
+ * @v: a 64-bit value
+ * @cb: a callback
+ *
+ * This provides a way for iterating all QPs.
+ *
+ * The @cb is a user-defined callback and @v is a 64-bit
+ * value passed to and relevant for processing in the
+ * cb.  An example use case would be to alter QP processing
+ * based on criteria not part of the rvt_qp.
+ *
+ * The code has an internal iterator to simplify
+ * non seq_file use cases.
+ */
+void rvt_qp_iter(struct rvt_dev_info *rdi,
+		 u64 v,
+		 void (*cb)(struct rvt_qp *qp, u64 v))
+{
+	int ret;
+	struct rvt_qp_iter i = {
+		.rdi = rdi,
+		.specials = rdi->ibdev.phys_port_cnt * 2,
+		.v = v,
+		.cb = cb
+	};
+
+	rcu_read_lock();
+	do {
+		ret = rvt_qp_iter_next(&i);
+		if (!ret) {
+			rvt_get_qp(i.qp);
+			rcu_read_unlock();
+			i.cb(i.qp, i.v);
+			rcu_read_lock();
+			rvt_put_qp(i.qp);
+		}
+	} while (!ret);
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(rvt_qp_iter);
+
+/*
+ * This should be called with s_lock and r_lock held.
+ */
+void rvt_send_complete(struct rvt_qp *qp, struct rvt_swqe *wqe,
+		       enum ib_wc_status status)
+{
+	u32 old_last, last;
+	struct rvt_dev_info *rdi;
+
+	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_OR_FLUSH_SEND))
+		return;
+	rdi = ib_to_rvt(qp->ibqp.device);
+
+	old_last = qp->s_last;
+	trace_rvt_qp_send_completion(qp, wqe, old_last);
+	last = rvt_qp_complete_swqe(qp, wqe, rdi->wc_opcode[wqe->wr.opcode],
+				    status);
+	if (qp->s_acked == old_last)
+		qp->s_acked = last;
+	if (qp->s_cur == old_last)
+		qp->s_cur = last;
+	if (qp->s_tail == old_last)
+		qp->s_tail = last;
+	if (qp->state == IB_QPS_SQD && last == qp->s_cur)
+		qp->s_draining = 0;
+}
+EXPORT_SYMBOL(rvt_send_complete);
+
+/**
+ * rvt_copy_sge - copy data to SGE memory
+ * @qp: associated QP
+ * @ss: the SGE state
+ * @data: the data to copy
+ * @length: the length of the data
+ * @release: boolean to release MR
+ * @copy_last: do a separate copy of the last 8 bytes
+ */
+void rvt_copy_sge(struct rvt_qp *qp, struct rvt_sge_state *ss,
+		  void *data, u32 length,
+		  bool release, bool copy_last)
+{
+	struct rvt_sge *sge = &ss->sge;
+	int i;
+	bool in_last = false;
+	bool cacheless_copy = false;
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+	struct rvt_wss *wss = rdi->wss;
+	unsigned int sge_copy_mode = rdi->dparms.sge_copy_mode;
+
+	if (sge_copy_mode == RVT_SGE_COPY_CACHELESS) {
+		cacheless_copy = length >= PAGE_SIZE;
+	} else if (sge_copy_mode == RVT_SGE_COPY_ADAPTIVE) {
+		if (length >= PAGE_SIZE) {
+			/*
+			 * NOTE: this *assumes*:
+			 * o The first vaddr is the dest.
+			 * o If multiple pages, then vaddr is sequential.
+			 */
+			wss_insert(wss, sge->vaddr);
+			if (length >= (2 * PAGE_SIZE))
+				wss_insert(wss, (sge->vaddr + PAGE_SIZE));
+
+			cacheless_copy = wss_exceeds_threshold(wss);
+		} else {
+			wss_advance_clean_counter(wss);
+		}
+	}
+
+	if (copy_last) {
+		if (length > 8) {
+			length -= 8;
+		} else {
+			copy_last = false;
+			in_last = true;
+		}
+	}
+
+again:
+	while (length) {
+		u32 len = rvt_get_sge_length(sge, length);
+
+		WARN_ON_ONCE(len == 0);
+		if (unlikely(in_last)) {
+			/* enforce byte transfer ordering */
+			for (i = 0; i < len; i++)
+				((u8 *)sge->vaddr)[i] = ((u8 *)data)[i];
+		} else if (cacheless_copy) {
+			cacheless_memcpy(sge->vaddr, data, len);
+		} else {
+			memcpy(sge->vaddr, data, len);
+		}
+		rvt_update_sge(ss, len, release);
+		data += len;
+		length -= len;
+	}
+
+	if (copy_last) {
+		copy_last = false;
+		in_last = true;
+		length = 8;
+		goto again;
+	}
+}
+EXPORT_SYMBOL(rvt_copy_sge);
+
+static enum ib_wc_status loopback_qp_drop(struct rvt_ibport *rvp,
+					  struct rvt_qp *sqp)
+{
+	rvp->n_pkt_drops++;
+	/*
+	 * For RC, the requester would timeout and retry so
+	 * shortcut the timeouts and just signal too many retries.
+	 */
+	return sqp->ibqp.qp_type == IB_QPT_RC ?
+		IB_WC_RETRY_EXC_ERR : IB_WC_SUCCESS;
+}
+
+/**
+ * rvt_ruc_loopback - handle UC and RC loopback requests
+ * @sqp: the sending QP
+ *
+ * This is called from rvt_do_send() to forward a WQE addressed to the same HFI
+ * Note that although we are single threaded due to the send engine, we still
+ * have to protect against post_send().  We don't have to worry about
+ * receive interrupts since this is a connected protocol and all packets
+ * will pass through here.
+ */
+void rvt_ruc_loopback(struct rvt_qp *sqp)
+{
+	struct rvt_ibport *rvp =  NULL;
+	struct rvt_dev_info *rdi = ib_to_rvt(sqp->ibqp.device);
+	struct rvt_qp *qp;
+	struct rvt_swqe *wqe;
+	struct rvt_sge *sge;
+	unsigned long flags;
+	struct ib_wc wc;
+	u64 sdata;
+	atomic64_t *maddr;
+	enum ib_wc_status send_status;
+	bool release;
+	int ret;
+	bool copy_last = false;
+	int local_ops = 0;
+
+	rcu_read_lock();
+	rvp = rdi->ports[sqp->port_num - 1];
+
+	/*
+	 * Note that we check the responder QP state after
+	 * checking the requester's state.
+	 */
+
+	qp = rvt_lookup_qpn(ib_to_rvt(sqp->ibqp.device), rvp,
+			    sqp->remote_qpn);
+
+	spin_lock_irqsave(&sqp->s_lock, flags);
+
+	/* Return if we are already busy processing a work request. */
+	if ((sqp->s_flags & (RVT_S_BUSY | RVT_S_ANY_WAIT)) ||
+	    !(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_OR_FLUSH_SEND))
+		goto unlock;
+
+	sqp->s_flags |= RVT_S_BUSY;
+
+again:
+	if (sqp->s_last == READ_ONCE(sqp->s_head))
+		goto clr_busy;
+	wqe = rvt_get_swqe_ptr(sqp, sqp->s_last);
+
+	/* Return if it is not OK to start a new work request. */
+	if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_NEXT_SEND_OK)) {
+		if (!(ib_rvt_state_ops[sqp->state] & RVT_FLUSH_SEND))
+			goto clr_busy;
+		/* We are in the error state, flush the work request. */
+		send_status = IB_WC_WR_FLUSH_ERR;
+		goto flush_send;
+	}
+
+	/*
+	 * We can rely on the entry not changing without the s_lock
+	 * being held until we update s_last.
+	 * We increment s_cur to indicate s_last is in progress.
+	 */
+	if (sqp->s_last == sqp->s_cur) {
+		if (++sqp->s_cur >= sqp->s_size)
+			sqp->s_cur = 0;
+	}
+	spin_unlock_irqrestore(&sqp->s_lock, flags);
+
+	if (!qp) {
+		send_status = loopback_qp_drop(rvp, sqp);
+		goto serr_no_r_lock;
+	}
+	spin_lock_irqsave(&qp->r_lock, flags);
+	if (!(ib_rvt_state_ops[qp->state] & RVT_PROCESS_RECV_OK) ||
+	    qp->ibqp.qp_type != sqp->ibqp.qp_type) {
+		send_status = loopback_qp_drop(rvp, sqp);
+		goto serr;
+	}
+
+	memset(&wc, 0, sizeof(wc));
+	send_status = IB_WC_SUCCESS;
+
+	release = true;
+	sqp->s_sge.sge = wqe->sg_list[0];
+	sqp->s_sge.sg_list = wqe->sg_list + 1;
+	sqp->s_sge.num_sge = wqe->wr.num_sge;
+	sqp->s_len = wqe->length;
+	switch (wqe->wr.opcode) {
+	case IB_WR_REG_MR:
+		goto send_comp;
+
+	case IB_WR_LOCAL_INV:
+		if (!(wqe->wr.send_flags & RVT_SEND_COMPLETION_ONLY)) {
+			if (rvt_invalidate_rkey(sqp,
+						wqe->wr.ex.invalidate_rkey))
+				send_status = IB_WC_LOC_PROT_ERR;
+			local_ops = 1;
+		}
+		goto send_comp;
+
+	case IB_WR_SEND_WITH_INV:
+	case IB_WR_SEND_WITH_IMM:
+	case IB_WR_SEND:
+		ret = rvt_get_rwqe(qp, false);
+		if (ret < 0)
+			goto op_err;
+		if (!ret)
+			goto rnr_nak;
+		if (wqe->length > qp->r_len)
+			goto inv_err;
+		switch (wqe->wr.opcode) {
+		case IB_WR_SEND_WITH_INV:
+			if (!rvt_invalidate_rkey(qp,
+						 wqe->wr.ex.invalidate_rkey)) {
+				wc.wc_flags = IB_WC_WITH_INVALIDATE;
+				wc.ex.invalidate_rkey =
+					wqe->wr.ex.invalidate_rkey;
+			}
+			break;
+		case IB_WR_SEND_WITH_IMM:
+			wc.wc_flags = IB_WC_WITH_IMM;
+			wc.ex.imm_data = wqe->wr.ex.imm_data;
+			break;
+		default:
+			break;
+		}
+		break;
+
+	case IB_WR_RDMA_WRITE_WITH_IMM:
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
+			goto inv_err;
+		wc.wc_flags = IB_WC_WITH_IMM;
+		wc.ex.imm_data = wqe->wr.ex.imm_data;
+		ret = rvt_get_rwqe(qp, true);
+		if (ret < 0)
+			goto op_err;
+		if (!ret)
+			goto rnr_nak;
+		/* skip copy_last set and qp_access_flags recheck */
+		goto do_write;
+	case IB_WR_RDMA_WRITE:
+		copy_last = rvt_is_user_qp(qp);
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_WRITE)))
+			goto inv_err;
+do_write:
+		if (wqe->length == 0)
+			break;
+		if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, wqe->length,
+					  wqe->rdma_wr.remote_addr,
+					  wqe->rdma_wr.rkey,
+					  IB_ACCESS_REMOTE_WRITE)))
+			goto acc_err;
+		qp->r_sge.sg_list = NULL;
+		qp->r_sge.num_sge = 1;
+		qp->r_sge.total_len = wqe->length;
+		break;
+
+	case IB_WR_RDMA_READ:
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_READ)))
+			goto inv_err;
+		if (unlikely(!rvt_rkey_ok(qp, &sqp->s_sge.sge, wqe->length,
+					  wqe->rdma_wr.remote_addr,
+					  wqe->rdma_wr.rkey,
+					  IB_ACCESS_REMOTE_READ)))
+			goto acc_err;
+		release = false;
+		sqp->s_sge.sg_list = NULL;
+		sqp->s_sge.num_sge = 1;
+		qp->r_sge.sge = wqe->sg_list[0];
+		qp->r_sge.sg_list = wqe->sg_list + 1;
+		qp->r_sge.num_sge = wqe->wr.num_sge;
+		qp->r_sge.total_len = wqe->length;
+		break;
+
+	case IB_WR_ATOMIC_CMP_AND_SWP:
+	case IB_WR_ATOMIC_FETCH_AND_ADD:
+		if (unlikely(!(qp->qp_access_flags & IB_ACCESS_REMOTE_ATOMIC)))
+			goto inv_err;
+		if (unlikely(wqe->atomic_wr.remote_addr & (sizeof(u64) - 1)))
+			goto inv_err;
+		if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, sizeof(u64),
+					  wqe->atomic_wr.remote_addr,
+					  wqe->atomic_wr.rkey,
+					  IB_ACCESS_REMOTE_ATOMIC)))
+			goto acc_err;
+		/* Perform atomic OP and save result. */
+		maddr = (atomic64_t *)qp->r_sge.sge.vaddr;
+		sdata = wqe->atomic_wr.compare_add;
+		*(u64 *)sqp->s_sge.sge.vaddr =
+			(wqe->wr.opcode == IB_WR_ATOMIC_FETCH_AND_ADD) ?
+			(u64)atomic64_add_return(sdata, maddr) - sdata :
+			(u64)cmpxchg((u64 *)qp->r_sge.sge.vaddr,
+				      sdata, wqe->atomic_wr.swap);
+		rvt_put_mr(qp->r_sge.sge.mr);
+		qp->r_sge.num_sge = 0;
+		goto send_comp;
+
+	default:
+		send_status = IB_WC_LOC_QP_OP_ERR;
+		goto serr;
+	}
+
+	sge = &sqp->s_sge.sge;
+	while (sqp->s_len) {
+		u32 len = rvt_get_sge_length(sge, sqp->s_len);
+
+		WARN_ON_ONCE(len == 0);
+		rvt_copy_sge(qp, &qp->r_sge, sge->vaddr,
+			     len, release, copy_last);
+		rvt_update_sge(&sqp->s_sge, len, !release);
+		sqp->s_len -= len;
+	}
+	if (release)
+		rvt_put_ss(&qp->r_sge);
+
+	if (!test_and_clear_bit(RVT_R_WRID_VALID, &qp->r_aflags))
+		goto send_comp;
+
+	if (wqe->wr.opcode == IB_WR_RDMA_WRITE_WITH_IMM)
+		wc.opcode = IB_WC_RECV_RDMA_WITH_IMM;
+	else
+		wc.opcode = IB_WC_RECV;
+	wc.wr_id = qp->r_wr_id;
+	wc.status = IB_WC_SUCCESS;
+	wc.byte_len = wqe->length;
+	wc.qp = &qp->ibqp;
+	wc.src_qp = qp->remote_qpn;
+	wc.slid = rdma_ah_get_dlid(&qp->remote_ah_attr) & U16_MAX;
+	wc.sl = rdma_ah_get_sl(&qp->remote_ah_attr);
+	wc.port_num = 1;
+	/* Signal completion event if the solicited bit is set. */
+	rvt_recv_cq(qp, &wc, wqe->wr.send_flags & IB_SEND_SOLICITED);
+
+send_comp:
+	spin_unlock_irqrestore(&qp->r_lock, flags);
+	spin_lock_irqsave(&sqp->s_lock, flags);
+	rvp->n_loop_pkts++;
+flush_send:
+	sqp->s_rnr_retry = sqp->s_rnr_retry_cnt;
+	spin_lock(&sqp->r_lock);
+	rvt_send_complete(sqp, wqe, send_status);
+	spin_unlock(&sqp->r_lock);
+	if (local_ops) {
+		atomic_dec(&sqp->local_ops_pending);
+		local_ops = 0;
+	}
+	goto again;
+
+rnr_nak:
+	/* Handle RNR NAK */
+	if (qp->ibqp.qp_type == IB_QPT_UC)
+		goto send_comp;
+	rvp->n_rnr_naks++;
+	/*
+	 * Note: we don't need the s_lock held since the BUSY flag
+	 * makes this single threaded.
+	 */
+	if (sqp->s_rnr_retry == 0) {
+		send_status = IB_WC_RNR_RETRY_EXC_ERR;
+		goto serr;
+	}
+	if (sqp->s_rnr_retry_cnt < 7)
+		sqp->s_rnr_retry--;
+	spin_unlock_irqrestore(&qp->r_lock, flags);
+	spin_lock_irqsave(&sqp->s_lock, flags);
+	if (!(ib_rvt_state_ops[sqp->state] & RVT_PROCESS_RECV_OK))
+		goto clr_busy;
+	rvt_add_rnr_timer(sqp, qp->r_min_rnr_timer <<
+				IB_AETH_CREDIT_SHIFT);
+	goto clr_busy;
+
+op_err:
+	send_status = IB_WC_REM_OP_ERR;
+	wc.status = IB_WC_LOC_QP_OP_ERR;
+	goto err;
+
+inv_err:
+	send_status =
+		sqp->ibqp.qp_type == IB_QPT_RC ?
+			IB_WC_REM_INV_REQ_ERR :
+			IB_WC_SUCCESS;
+	wc.status = IB_WC_LOC_QP_OP_ERR;
+	goto err;
+
+acc_err:
+	send_status = IB_WC_REM_ACCESS_ERR;
+	wc.status = IB_WC_LOC_PROT_ERR;
+err:
+	/* responder goes to error state */
+	rvt_rc_error(qp, wc.status);
+
+serr:
+	spin_unlock_irqrestore(&qp->r_lock, flags);
+serr_no_r_lock:
+	spin_lock_irqsave(&sqp->s_lock, flags);
+	spin_lock(&sqp->r_lock);
+	rvt_send_complete(sqp, wqe, send_status);
+	spin_unlock(&sqp->r_lock);
+	if (sqp->ibqp.qp_type == IB_QPT_RC) {
+		int lastwqe;
+
+		spin_lock(&sqp->r_lock);
+		lastwqe = rvt_error_qp(sqp, IB_WC_WR_FLUSH_ERR);
+		spin_unlock(&sqp->r_lock);
+
+		sqp->s_flags &= ~RVT_S_BUSY;
+		spin_unlock_irqrestore(&sqp->s_lock, flags);
+		if (lastwqe) {
+			struct ib_event ev;
+
+			ev.device = sqp->ibqp.device;
+			ev.element.qp = &sqp->ibqp;
+			ev.event = IB_EVENT_QP_LAST_WQE_REACHED;
+			sqp->ibqp.event_handler(&ev, sqp->ibqp.qp_context);
+		}
+		goto done;
+	}
+clr_busy:
+	sqp->s_flags &= ~RVT_S_BUSY;
+unlock:
+	spin_unlock_irqrestore(&sqp->s_lock, flags);
+done:
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(rvt_ruc_loopback);