diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c
new file mode 100644
index 0000000..a74ce8d
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/user_sdma.c
@@ -0,0 +1,1450 @@
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/uio.h>
+#include <linux/rbtree.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/mmu_context.h>
+#include <linux/module.h>
+
+#include "hfi.h"
+#include "sdma.h"
+#include "user_sdma.h"
+#include "sdma.h"
+#include "verbs.h"  /* for the headers */
+#include "common.h" /* for struct hfi1_tid_info */
+#include "trace.h"
+
+static uint hfi1_sdma_comp_ring_size = 128;
+module_param_named(sdma_comp_size, hfi1_sdma_comp_ring_size, uint, S_IRUGO);
+MODULE_PARM_DESC(sdma_comp_size, "Size of User SDMA completion ring. Default: 128");
+
+/* The maximum number of Data io vectors per message/request */
+#define MAX_VECTORS_PER_REQ 8
+/*
+ * Maximum number of packet to send from each message/request
+ * before moving to the next one.
+ */
+#define MAX_PKTS_PER_QUEUE 16
+
+#define num_pages(x) (1 + ((((x) - 1) & PAGE_MASK) >> PAGE_SHIFT))
+
+#define req_opcode(x) \
+	(((x) >> HFI1_SDMA_REQ_OPCODE_SHIFT) & HFI1_SDMA_REQ_OPCODE_MASK)
+#define req_version(x) \
+	(((x) >> HFI1_SDMA_REQ_VERSION_SHIFT) & HFI1_SDMA_REQ_OPCODE_MASK)
+#define req_iovcnt(x) \
+	(((x) >> HFI1_SDMA_REQ_IOVCNT_SHIFT) & HFI1_SDMA_REQ_IOVCNT_MASK)
+
+/* Number of BTH.PSN bits used for sequence number in expected rcvs */
+#define BTH_SEQ_MASK 0x7ffull
+
+/*
+ * Define fields in the KDETH header so we can update the header
+ * template.
+ */
+#define KDETH_OFFSET_SHIFT        0
+#define KDETH_OFFSET_MASK         0x7fff
+#define KDETH_OM_SHIFT            15
+#define KDETH_OM_MASK             0x1
+#define KDETH_TID_SHIFT           16
+#define KDETH_TID_MASK            0x3ff
+#define KDETH_TIDCTRL_SHIFT       26
+#define KDETH_TIDCTRL_MASK        0x3
+#define KDETH_INTR_SHIFT          28
+#define KDETH_INTR_MASK           0x1
+#define KDETH_SH_SHIFT            29
+#define KDETH_SH_MASK             0x1
+#define KDETH_HCRC_UPPER_SHIFT    16
+#define KDETH_HCRC_UPPER_MASK     0xff
+#define KDETH_HCRC_LOWER_SHIFT    24
+#define KDETH_HCRC_LOWER_MASK     0xff
+
+#define PBC2LRH(x) ((((x) & 0xfff) << 2) - 4)
+#define LRH2PBC(x) ((((x) >> 2) + 1) & 0xfff)
+
+#define KDETH_GET(val, field)						\
+	(((le32_to_cpu((val))) >> KDETH_##field##_SHIFT) & KDETH_##field##_MASK)
+#define KDETH_SET(dw, field, val) do {					\
+		u32 dwval = le32_to_cpu(dw);				\
+		dwval &= ~(KDETH_##field##_MASK << KDETH_##field##_SHIFT); \
+		dwval |= (((val) & KDETH_##field##_MASK) << \
+			  KDETH_##field##_SHIFT);			\
+		dw = cpu_to_le32(dwval);				\
+	} while (0)
+
+#define AHG_HEADER_SET(arr, idx, dw, bit, width, value)			\
+	do {								\
+		if ((idx) < ARRAY_SIZE((arr)))				\
+			(arr)[(idx++)] = sdma_build_ahg_descriptor(	\
+				(__force u16)(value), (dw), (bit),	\
+							(width));	\
+		else							\
+			return -ERANGE;					\
+	} while (0)
+
+/* KDETH OM multipliers and switch over point */
+#define KDETH_OM_SMALL     4
+#define KDETH_OM_LARGE     64
+#define KDETH_OM_MAX_SIZE  ((1 << (KDETH_OM_LARGE / KDETH_OM_SMALL)) - 1)
+
+/* Last packet in the request */
+#define USER_SDMA_TXREQ_FLAGS_LAST_PKT   (1 << 0)
+
+#define SDMA_REQ_IN_USE     0
+#define SDMA_REQ_FOR_THREAD 1
+#define SDMA_REQ_SEND_DONE  2
+#define SDMA_REQ_HAVE_AHG   3
+#define SDMA_REQ_HAS_ERROR  4
+#define SDMA_REQ_DONE_ERROR 5
+
+#define SDMA_PKT_Q_INACTIVE (1 << 0)
+#define SDMA_PKT_Q_ACTIVE   (1 << 1)
+#define SDMA_PKT_Q_DEFERRED (1 << 2)
+
+/*
+ * Maximum retry attempts to submit a TX request
+ * before putting the process to sleep.
+ */
+#define MAX_DEFER_RETRY_COUNT 1
+
+static unsigned initial_pkt_count = 8;
+
+#define SDMA_IOWAIT_TIMEOUT 1000 /* in milliseconds */
+
+struct user_sdma_iovec {
+	struct iovec iov;
+	/* number of pages in this vector */
+	unsigned npages;
+	/* array of pinned pages for this vector */
+	struct page **pages;
+	/* offset into the virtual address space of the vector at
+	 * which we last left off. */
+	u64 offset;
+};
+
+struct user_sdma_request {
+	struct sdma_req_info info;
+	struct hfi1_user_sdma_pkt_q *pq;
+	struct hfi1_user_sdma_comp_q *cq;
+	/* This is the original header from user space */
+	struct hfi1_pkt_header hdr;
+	/*
+	 * Pointer to the SDMA engine for this request.
+	 * Since different request could be on different VLs,
+	 * each request will need it's own engine pointer.
+	 */
+	struct sdma_engine *sde;
+	u8 ahg_idx;
+	u32 ahg[9];
+	/*
+	 * KDETH.Offset (Eager) field
+	 * We need to remember the initial value so the headers
+	 * can be updated properly.
+	 */
+	u32 koffset;
+	/*
+	 * KDETH.OFFSET (TID) field
+	 * The offset can cover multiple packets, depending on the
+	 * size of the TID entry.
+	 */
+	u32 tidoffset;
+	/*
+	 * KDETH.OM
+	 * Remember this because the header template always sets it
+	 * to 0.
+	 */
+	u8 omfactor;
+	/*
+	 * pointer to the user's task_struct. We are going to
+	 * get a reference to it so we can process io vectors
+	 * at a later time.
+	 */
+	struct task_struct *user_proc;
+	/*
+	 * pointer to the user's mm_struct. We are going to
+	 * get a reference to it so it doesn't get freed
+	 * since we might not be in process context when we
+	 * are processing the iov's.
+	 * Using this mm_struct, we can get vma based on the
+	 * iov's address (find_vma()).
+	 */
+	struct mm_struct *user_mm;
+	/*
+	 * We copy the iovs for this request (based on
+	 * info.iovcnt). These are only the data vectors
+	 */
+	unsigned data_iovs;
+	/* total length of the data in the request */
+	u32 data_len;
+	/* progress index moving along the iovs array */
+	unsigned iov_idx;
+	struct user_sdma_iovec iovs[MAX_VECTORS_PER_REQ];
+	/* number of elements copied to the tids array */
+	u8 n_tids;
+	/* TID array values copied from the tid_iov vector */
+	u32 *tids;
+	u8 tididx;
+	u32 sent;
+	u64 seqnum;
+	spinlock_t list_lock;
+	struct list_head txps;
+	unsigned long flags;
+};
+
+struct user_sdma_txreq {
+	/* Packet header for the txreq */
+	struct hfi1_pkt_header hdr;
+	struct sdma_txreq txreq;
+	struct user_sdma_request *req;
+	struct user_sdma_iovec *iovec1;
+	struct user_sdma_iovec *iovec2;
+	u16 flags;
+	unsigned busycount;
+	u64 seqnum;
+};
+
+#define SDMA_DBG(req, fmt, ...)				     \
+	hfi1_cdbg(SDMA, "[%u:%u:%u:%u] " fmt, (req)->pq->dd->unit, \
+		 (req)->pq->ctxt, (req)->pq->subctxt, (req)->info.comp_idx, \
+		 ##__VA_ARGS__)
+#define SDMA_Q_DBG(pq, fmt, ...)			 \
+	hfi1_cdbg(SDMA, "[%u:%u:%u] " fmt, (pq)->dd->unit, (pq)->ctxt, \
+		 (pq)->subctxt, ##__VA_ARGS__)
+
+static int user_sdma_send_pkts(struct user_sdma_request *, unsigned);
+static int num_user_pages(const struct iovec *);
+static void user_sdma_txreq_cb(struct sdma_txreq *, int, int);
+static void user_sdma_free_request(struct user_sdma_request *);
+static int pin_vector_pages(struct user_sdma_request *,
+			    struct user_sdma_iovec *);
+static void unpin_vector_pages(struct user_sdma_iovec *);
+static int check_header_template(struct user_sdma_request *,
+				 struct hfi1_pkt_header *, u32, u32);
+static int set_txreq_header(struct user_sdma_request *,
+			    struct user_sdma_txreq *, u32);
+static int set_txreq_header_ahg(struct user_sdma_request *,
+				struct user_sdma_txreq *, u32);
+static inline void set_comp_state(struct user_sdma_request *,
+					enum hfi1_sdma_comp_state, int);
+static inline u32 set_pkt_bth_psn(__be32, u8, u32);
+static inline u32 get_lrh_len(struct hfi1_pkt_header, u32 len);
+
+static int defer_packet_queue(
+	struct sdma_engine *,
+	struct iowait *,
+	struct sdma_txreq *,
+	unsigned seq);
+static void activate_packet_queue(struct iowait *, int);
+
+static inline int iovec_may_free(struct user_sdma_iovec *iovec,
+				       void (*free)(struct user_sdma_iovec *))
+{
+	if (ACCESS_ONCE(iovec->offset) == iovec->iov.iov_len) {
+		free(iovec);
+		return 1;
+	}
+	return 0;
+}
+
+static inline void iovec_set_complete(struct user_sdma_iovec *iovec)
+{
+	iovec->offset = iovec->iov.iov_len;
+}
+
+static int defer_packet_queue(
+	struct sdma_engine *sde,
+	struct iowait *wait,
+	struct sdma_txreq *txreq,
+	unsigned seq)
+{
+	struct hfi1_user_sdma_pkt_q *pq =
+		container_of(wait, struct hfi1_user_sdma_pkt_q, busy);
+	struct hfi1_ibdev *dev = &pq->dd->verbs_dev;
+	struct user_sdma_txreq *tx =
+		container_of(txreq, struct user_sdma_txreq, txreq);
+
+	if (sdma_progress(sde, seq, txreq)) {
+		if (tx->busycount++ < MAX_DEFER_RETRY_COUNT)
+			goto eagain;
+	}
+	/*
+	 * We are assuming that if the list is enqueued somewhere, it
+	 * is to the dmawait list since that is the only place where
+	 * it is supposed to be enqueued.
+	 */
+	xchg(&pq->state, SDMA_PKT_Q_DEFERRED);
+	spin_lock(&dev->pending_lock);
+	if (list_empty(&pq->busy.list))
+		list_add_tail(&pq->busy.list, &sde->dmawait);
+	spin_unlock(&dev->pending_lock);
+	return -EBUSY;
+eagain:
+	return -EAGAIN;
+}
+
+static void activate_packet_queue(struct iowait *wait, int reason)
+{
+	struct hfi1_user_sdma_pkt_q *pq =
+		container_of(wait, struct hfi1_user_sdma_pkt_q, busy);
+	xchg(&pq->state, SDMA_PKT_Q_ACTIVE);
+	wake_up(&wait->wait_dma);
+};
+
+static void sdma_kmem_cache_ctor(void *obj)
+{
+	struct user_sdma_txreq *tx = (struct user_sdma_txreq *)obj;
+
+	memset(tx, 0, sizeof(*tx));
+}
+
+int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt, struct file *fp)
+{
+	int ret = 0;
+	unsigned memsize;
+	char buf[64];
+	struct hfi1_devdata *dd;
+	struct hfi1_user_sdma_comp_q *cq;
+	struct hfi1_user_sdma_pkt_q *pq;
+	unsigned long flags;
+
+	if (!uctxt || !fp) {
+		ret = -EBADF;
+		goto done;
+	}
+
+	if (!hfi1_sdma_comp_ring_size) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	dd = uctxt->dd;
+
+	pq = kzalloc(sizeof(*pq), GFP_KERNEL);
+	if (!pq) {
+		dd_dev_err(dd,
+			   "[%u:%u] Failed to allocate SDMA request struct\n",
+			   uctxt->ctxt, subctxt_fp(fp));
+		goto pq_nomem;
+	}
+	memsize = sizeof(*pq->reqs) * hfi1_sdma_comp_ring_size;
+	pq->reqs = kmalloc(memsize, GFP_KERNEL);
+	if (!pq->reqs) {
+		dd_dev_err(dd,
+			   "[%u:%u] Failed to allocate SDMA request queue (%u)\n",
+			   uctxt->ctxt, subctxt_fp(fp), memsize);
+		goto pq_reqs_nomem;
+	}
+	INIT_LIST_HEAD(&pq->list);
+	pq->dd = dd;
+	pq->ctxt = uctxt->ctxt;
+	pq->subctxt = subctxt_fp(fp);
+	pq->n_max_reqs = hfi1_sdma_comp_ring_size;
+	pq->state = SDMA_PKT_Q_INACTIVE;
+	atomic_set(&pq->n_reqs, 0);
+
+	iowait_init(&pq->busy, 0, NULL, defer_packet_queue,
+		    activate_packet_queue);
+	pq->reqidx = 0;
+	snprintf(buf, 64, "txreq-kmem-cache-%u-%u-%u", dd->unit, uctxt->ctxt,
+		 subctxt_fp(fp));
+	pq->txreq_cache = kmem_cache_create(buf,
+			       sizeof(struct user_sdma_txreq),
+					    L1_CACHE_BYTES,
+					    SLAB_HWCACHE_ALIGN,
+					    sdma_kmem_cache_ctor);
+	if (!pq->txreq_cache) {
+		dd_dev_err(dd, "[%u] Failed to allocate TxReq cache\n",
+			   uctxt->ctxt);
+		goto pq_txreq_nomem;
+	}
+	user_sdma_pkt_fp(fp) = pq;
+	cq = kzalloc(sizeof(*cq), GFP_KERNEL);
+	if (!cq) {
+		dd_dev_err(dd,
+			   "[%u:%u] Failed to allocate SDMA completion queue\n",
+			   uctxt->ctxt, subctxt_fp(fp));
+		goto cq_nomem;
+	}
+
+	memsize = ALIGN(sizeof(*cq->comps) * hfi1_sdma_comp_ring_size,
+			PAGE_SIZE);
+	cq->comps = vmalloc_user(memsize);
+	if (!cq->comps) {
+		dd_dev_err(dd,
+		      "[%u:%u] Failed to allocate SDMA completion queue entries\n",
+		      uctxt->ctxt, subctxt_fp(fp));
+		goto cq_comps_nomem;
+	}
+	cq->nentries = hfi1_sdma_comp_ring_size;
+	user_sdma_comp_fp(fp) = cq;
+
+	spin_lock_irqsave(&uctxt->sdma_qlock, flags);
+	list_add(&pq->list, &uctxt->sdma_queues);
+	spin_unlock_irqrestore(&uctxt->sdma_qlock, flags);
+	goto done;
+
+cq_comps_nomem:
+	kfree(cq);
+cq_nomem:
+	kmem_cache_destroy(pq->txreq_cache);
+pq_txreq_nomem:
+	kfree(pq->reqs);
+pq_reqs_nomem:
+	kfree(pq);
+	user_sdma_pkt_fp(fp) = NULL;
+pq_nomem:
+	ret = -ENOMEM;
+done:
+	return ret;
+}
+
+int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd)
+{
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct hfi1_user_sdma_pkt_q *pq;
+	unsigned long flags;
+
+	hfi1_cdbg(SDMA, "[%u:%u:%u] Freeing user SDMA queues", uctxt->dd->unit,
+		  uctxt->ctxt, fd->subctxt);
+	pq = fd->pq;
+	if (pq) {
+		u16 i, j;
+
+		spin_lock_irqsave(&uctxt->sdma_qlock, flags);
+		if (!list_empty(&pq->list))
+			list_del_init(&pq->list);
+		spin_unlock_irqrestore(&uctxt->sdma_qlock, flags);
+		iowait_sdma_drain(&pq->busy);
+		if (pq->reqs) {
+			for (i = 0, j = 0; i < atomic_read(&pq->n_reqs) &&
+				     j < pq->n_max_reqs; j++) {
+				struct user_sdma_request *req = &pq->reqs[j];
+
+				if (test_bit(SDMA_REQ_IN_USE, &req->flags)) {
+					set_comp_state(req, ERROR, -ECOMM);
+					user_sdma_free_request(req);
+					i++;
+				}
+			}
+			kfree(pq->reqs);
+		}
+		if (pq->txreq_cache)
+			kmem_cache_destroy(pq->txreq_cache);
+		kfree(pq);
+		fd->pq = NULL;
+	}
+	if (fd->cq) {
+		if (fd->cq->comps)
+			vfree(fd->cq->comps);
+		kfree(fd->cq);
+		fd->cq = NULL;
+	}
+	return 0;
+}
+
+int hfi1_user_sdma_process_request(struct file *fp, struct iovec *iovec,
+				   unsigned long dim, unsigned long *count)
+{
+	int ret = 0, i = 0, sent;
+	struct hfi1_ctxtdata *uctxt = ctxt_fp(fp);
+	struct hfi1_user_sdma_pkt_q *pq = user_sdma_pkt_fp(fp);
+	struct hfi1_user_sdma_comp_q *cq = user_sdma_comp_fp(fp);
+	struct hfi1_devdata *dd = pq->dd;
+	unsigned long idx = 0;
+	u8 pcount = initial_pkt_count;
+	struct sdma_req_info info;
+	struct user_sdma_request *req;
+	u8 opcode, sc, vl;
+
+	if (iovec[idx].iov_len < sizeof(info) + sizeof(req->hdr)) {
+		hfi1_cdbg(
+		   SDMA,
+		   "[%u:%u:%u] First vector not big enough for header %lu/%lu",
+		   dd->unit, uctxt->ctxt, subctxt_fp(fp),
+		   iovec[idx].iov_len, sizeof(info) + sizeof(req->hdr));
+		ret = -EINVAL;
+		goto done;
+	}
+	ret = copy_from_user(&info, iovec[idx].iov_base, sizeof(info));
+	if (ret) {
+		hfi1_cdbg(SDMA, "[%u:%u:%u] Failed to copy info QW (%d)",
+			  dd->unit, uctxt->ctxt, subctxt_fp(fp), ret);
+		ret = -EFAULT;
+		goto done;
+	}
+	trace_hfi1_sdma_user_reqinfo(dd, uctxt->ctxt, subctxt_fp(fp),
+				     (u16 *)&info);
+	if (cq->comps[info.comp_idx].status == QUEUED) {
+		hfi1_cdbg(SDMA, "[%u:%u:%u] Entry %u is in QUEUED state",
+			  dd->unit, uctxt->ctxt, subctxt_fp(fp),
+			  info.comp_idx);
+		ret = -EBADSLT;
+		goto done;
+	}
+	if (!info.fragsize) {
+		hfi1_cdbg(SDMA,
+			  "[%u:%u:%u:%u] Request does not specify fragsize",
+			  dd->unit, uctxt->ctxt, subctxt_fp(fp), info.comp_idx);
+		ret = -EINVAL;
+		goto done;
+	}
+	/*
+	 * We've done all the safety checks that we can up to this point,
+	 * "allocate" the request entry.
+	 */
+	hfi1_cdbg(SDMA, "[%u:%u:%u] Using req/comp entry %u\n", dd->unit,
+		  uctxt->ctxt, subctxt_fp(fp), info.comp_idx);
+	req = pq->reqs + info.comp_idx;
+	memset(req, 0, sizeof(*req));
+	/* Mark the request as IN_USE before we start filling it in. */
+	set_bit(SDMA_REQ_IN_USE, &req->flags);
+	req->data_iovs = req_iovcnt(info.ctrl) - 1;
+	req->pq = pq;
+	req->cq = cq;
+	INIT_LIST_HEAD(&req->txps);
+	spin_lock_init(&req->list_lock);
+	memcpy(&req->info, &info, sizeof(info));
+
+	if (req_opcode(info.ctrl) == EXPECTED)
+		req->data_iovs--;
+
+	if (!info.npkts || req->data_iovs > MAX_VECTORS_PER_REQ) {
+		SDMA_DBG(req, "Too many vectors (%u/%u)", req->data_iovs,
+			 MAX_VECTORS_PER_REQ);
+		ret = -EINVAL;
+		goto done;
+	}
+	/* Copy the header from the user buffer */
+	ret = copy_from_user(&req->hdr, iovec[idx].iov_base + sizeof(info),
+			     sizeof(req->hdr));
+	if (ret) {
+		SDMA_DBG(req, "Failed to copy header template (%d)", ret);
+		ret = -EFAULT;
+		goto free_req;
+	}
+
+	/* If Static rate control is not enabled, sanitize the header. */
+	if (!HFI1_CAP_IS_USET(STATIC_RATE_CTRL))
+		req->hdr.pbc[2] = 0;
+
+	/* Validate the opcode. Do not trust packets from user space blindly. */
+	opcode = (be32_to_cpu(req->hdr.bth[0]) >> 24) & 0xff;
+	if ((opcode & USER_OPCODE_CHECK_MASK) !=
+	     USER_OPCODE_CHECK_VAL) {
+		SDMA_DBG(req, "Invalid opcode (%d)", opcode);
+		ret = -EINVAL;
+		goto free_req;
+	}
+	/*
+	 * Validate the vl. Do not trust packets from user space blindly.
+	 * VL comes from PBC, SC comes from LRH, and the VL needs to
+	 * match the SC look up.
+	 */
+	vl = (le16_to_cpu(req->hdr.pbc[0]) >> 12) & 0xF;
+	sc = (((be16_to_cpu(req->hdr.lrh[0]) >> 12) & 0xF) |
+	      (((le16_to_cpu(req->hdr.pbc[1]) >> 14) & 0x1) << 4));
+	if (vl >= hfi1_num_vls(dd->pport->vls_operational) ||
+	    vl != sc_to_vlt(dd, sc)) {
+		SDMA_DBG(req, "Invalid SC(%u)/VL(%u)", sc, vl);
+		ret = -EINVAL;
+		goto free_req;
+	}
+
+	/*
+	 * Also should check the BTH.lnh. If it says the next header is GRH then
+	 * the RXE parsing will be off and will land in the middle of the KDETH
+	 * or miss it entirely.
+	 */
+	if ((be16_to_cpu(req->hdr.lrh[0]) & 0x3) == HFI1_LRH_GRH) {
+		SDMA_DBG(req, "User tried to pass in a GRH");
+		ret = -EINVAL;
+		goto free_req;
+	}
+
+	req->koffset = le32_to_cpu(req->hdr.kdeth.swdata[6]);
+	/* The KDETH.OM flag in the first packed (and header template) is
+	 * always 0. */
+	req->tidoffset = KDETH_GET(req->hdr.kdeth.ver_tid_offset, OFFSET) *
+		KDETH_OM_SMALL;
+	SDMA_DBG(req, "Initial TID offset %u", req->tidoffset);
+	idx++;
+
+	/* Save all the IO vector structures */
+	while (i < req->data_iovs) {
+		memcpy(&req->iovs[i].iov, iovec + idx++, sizeof(struct iovec));
+		req->iovs[i].offset = 0;
+		req->data_len += req->iovs[i++].iov.iov_len;
+	}
+	SDMA_DBG(req, "total data length %u", req->data_len);
+
+	if (pcount > req->info.npkts)
+		pcount = req->info.npkts;
+	/*
+	 * Copy any TID info
+	 * User space will provide the TID info only when the
+	 * request type is EXPECTED. This is true even if there is
+	 * only one packet in the request and the header is already
+	 * setup. The reason for the singular TID case is that the
+	 * driver needs to perform safety checks.
+	 */
+	if (req_opcode(req->info.ctrl) == EXPECTED) {
+		u16 ntids = iovec[idx].iov_len / sizeof(*req->tids);
+
+		if (!ntids || ntids > MAX_TID_PAIR_ENTRIES) {
+			ret = -EINVAL;
+			goto free_req;
+		}
+		req->tids = kcalloc(ntids, sizeof(*req->tids), GFP_KERNEL);
+		if (!req->tids) {
+			ret = -ENOMEM;
+			goto free_req;
+		}
+		/*
+		 * We have to copy all of the tids because they may vary
+		 * in size and, therefore, the TID count might not be
+		 * equal to the pkt count. However, there is no way to
+		 * tell at this point.
+		 */
+		ret = copy_from_user(req->tids, iovec[idx].iov_base,
+				     ntids * sizeof(*req->tids));
+		if (ret) {
+			SDMA_DBG(req, "Failed to copy %d TIDs (%d)",
+				 ntids, ret);
+			ret = -EFAULT;
+			goto free_req;
+		}
+		req->n_tids = ntids;
+		idx++;
+	}
+
+	/* Have to select the engine */
+	req->sde = sdma_select_engine_vl(dd,
+					 (u32)(uctxt->ctxt + subctxt_fp(fp)),
+					 vl);
+	if (!req->sde || !sdma_running(req->sde)) {
+		ret = -ECOMM;
+		goto free_req;
+	}
+
+	/* We don't need an AHG entry if the request contains only one packet */
+	if (req->info.npkts > 1 && HFI1_CAP_IS_USET(SDMA_AHG)) {
+		int ahg = sdma_ahg_alloc(req->sde);
+
+		if (likely(ahg >= 0)) {
+			req->ahg_idx = (u8)ahg;
+			set_bit(SDMA_REQ_HAVE_AHG, &req->flags);
+		}
+	}
+
+	set_comp_state(req, QUEUED, 0);
+	/* Send the first N packets in the request to buy us some time */
+	sent = user_sdma_send_pkts(req, pcount);
+	if (unlikely(sent < 0)) {
+		if (sent != -EBUSY) {
+			ret = sent;
+			goto send_err;
+		} else
+			sent = 0;
+	}
+	atomic_inc(&pq->n_reqs);
+
+	if (sent < req->info.npkts) {
+		/* Take the references to the user's task and mm_struct */
+		get_task_struct(current);
+		req->user_proc = current;
+
+		/*
+		 * This is a somewhat blocking send implementation.
+		 * The driver will block the caller until all packets of the
+		 * request have been submitted to the SDMA engine. However, it
+		 * will not wait for send completions.
+		 */
+		while (!test_bit(SDMA_REQ_SEND_DONE, &req->flags)) {
+			ret = user_sdma_send_pkts(req, pcount);
+			if (ret < 0) {
+				if (ret != -EBUSY)
+					goto send_err;
+				wait_event_interruptible_timeout(
+					pq->busy.wait_dma,
+					(pq->state == SDMA_PKT_Q_ACTIVE),
+					msecs_to_jiffies(
+						SDMA_IOWAIT_TIMEOUT));
+			}
+		}
+
+	}
+	ret = 0;
+	*count += idx;
+	goto done;
+send_err:
+	set_comp_state(req, ERROR, ret);
+free_req:
+	user_sdma_free_request(req);
+done:
+	return ret;
+}
+
+static inline u32 compute_data_length(struct user_sdma_request *req,
+					    struct user_sdma_txreq *tx)
+{
+	/*
+	 * Determine the proper size of the packet data.
+	 * The size of the data of the first packet is in the header
+	 * template. However, it includes the header and ICRC, which need
+	 * to be subtracted.
+	 * The size of the remaining packets is the minimum of the frag
+	 * size (MTU) or remaining data in the request.
+	 */
+	u32 len;
+
+	if (!req->seqnum) {
+		len = ((be16_to_cpu(req->hdr.lrh[2]) << 2) -
+		       (sizeof(tx->hdr) - 4));
+	} else if (req_opcode(req->info.ctrl) == EXPECTED) {
+		u32 tidlen = EXP_TID_GET(req->tids[req->tididx], LEN) *
+			PAGE_SIZE;
+		if (req->seqnum <= tidlen / req->info.fragsize) {
+			len = min(tidlen - req->tidoffset,
+				  (u32)req->info.fragsize);
+			if (unlikely(!len) && ++req->tididx < req->n_tids &&
+			    req->tids[req->tididx]) {
+				tidlen = EXP_TID_GET(req->tids[req->tididx],
+						     LEN) * PAGE_SIZE;
+				req->tidoffset = 0;
+				len = min_t(u32, tidlen, req->info.fragsize);
+			}
+			len = min(len, req->data_len - req->sent);
+		} else
+			len = min(req->data_len - req->sent,
+				  (u32)req->info.fragsize);
+	} else
+		len = min(req->data_len - req->sent, (u32)req->info.fragsize);
+	SDMA_DBG(req, "Data Length = %u", len);
+	return len;
+}
+
+static inline u32 get_lrh_len(struct hfi1_pkt_header hdr, u32 len)
+{
+	/* (Size of complete header - size of PBC) + 4B ICRC + data length */
+	return ((sizeof(hdr) - sizeof(hdr.pbc)) + 4 + len);
+}
+
+static int user_sdma_send_pkts(struct user_sdma_request *req, unsigned maxpkts)
+{
+	int ret = 0;
+	unsigned npkts = 0;
+	struct user_sdma_txreq *tx = NULL;
+	struct hfi1_user_sdma_pkt_q *pq = NULL;
+	struct user_sdma_iovec *iovec = NULL;
+
+	if (!req->pq) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	pq = req->pq;
+
+	/*
+	 * Check if we might have sent the entire request already
+	 */
+	if (unlikely(req->seqnum == req->info.npkts)) {
+		if (!list_empty(&req->txps))
+			goto dosend;
+		goto done;
+	}
+
+	if (!maxpkts || maxpkts > req->info.npkts - req->seqnum)
+		maxpkts = req->info.npkts - req->seqnum;
+
+	while (npkts < maxpkts) {
+		u32 datalen = 0, queued = 0, data_sent = 0;
+		u64 iov_offset = 0;
+
+		/*
+		 * Check whether any of the completions have come back
+		 * with errors. If so, we are not going to process any
+		 * more packets from this request.
+		 */
+		if (test_bit(SDMA_REQ_HAS_ERROR, &req->flags)) {
+			set_bit(SDMA_REQ_DONE_ERROR, &req->flags);
+			ret = -EFAULT;
+			goto done;
+		}
+
+		tx = kmem_cache_alloc(pq->txreq_cache, GFP_KERNEL);
+		if (!tx) {
+			ret = -ENOMEM;
+			goto done;
+		}
+		tx->flags = 0;
+		tx->req = req;
+		tx->busycount = 0;
+		tx->iovec1 = NULL;
+		tx->iovec2 = NULL;
+
+		if (req->seqnum == req->info.npkts - 1)
+			tx->flags |= USER_SDMA_TXREQ_FLAGS_LAST_PKT;
+
+		/*
+		 * Calculate the payload size - this is min of the fragment
+		 * (MTU) size or the remaining bytes in the request but only
+		 * if we have payload data.
+		 */
+		if (req->data_len) {
+			iovec = &req->iovs[req->iov_idx];
+			if (ACCESS_ONCE(iovec->offset) == iovec->iov.iov_len) {
+				if (++req->iov_idx == req->data_iovs) {
+					ret = -EFAULT;
+					goto free_txreq;
+				}
+				iovec = &req->iovs[req->iov_idx];
+				BUG_ON(iovec->offset);
+			}
+
+			/*
+			 * This request might include only a header and no user
+			 * data, so pin pages only if there is data and it the
+			 * pages have not been pinned already.
+			 */
+			if (unlikely(!iovec->pages && iovec->iov.iov_len)) {
+				ret = pin_vector_pages(req, iovec);
+				if (ret)
+					goto free_tx;
+			}
+
+			tx->iovec1 = iovec;
+			datalen = compute_data_length(req, tx);
+			if (!datalen) {
+				SDMA_DBG(req,
+					 "Request has data but pkt len is 0");
+				ret = -EFAULT;
+				goto free_tx;
+			}
+		}
+
+		if (test_bit(SDMA_REQ_HAVE_AHG, &req->flags)) {
+			if (!req->seqnum) {
+				u16 pbclen = le16_to_cpu(req->hdr.pbc[0]);
+				u32 lrhlen = get_lrh_len(req->hdr, datalen);
+				/*
+				 * Copy the request header into the tx header
+				 * because the HW needs a cacheline-aligned
+				 * address.
+				 * This copy can be optimized out if the hdr
+				 * member of user_sdma_request were also
+				 * cacheline aligned.
+				 */
+				memcpy(&tx->hdr, &req->hdr, sizeof(tx->hdr));
+				if (PBC2LRH(pbclen) != lrhlen) {
+					pbclen = (pbclen & 0xf000) |
+						LRH2PBC(lrhlen);
+					tx->hdr.pbc[0] = cpu_to_le16(pbclen);
+				}
+				ret = sdma_txinit_ahg(&tx->txreq,
+						      SDMA_TXREQ_F_AHG_COPY,
+						      sizeof(tx->hdr) + datalen,
+						      req->ahg_idx, 0, NULL, 0,
+						      user_sdma_txreq_cb);
+				if (ret)
+					goto free_tx;
+				ret = sdma_txadd_kvaddr(pq->dd, &tx->txreq,
+							&tx->hdr,
+							sizeof(tx->hdr));
+				if (ret)
+					goto free_txreq;
+			} else {
+				int changes;
+
+				changes = set_txreq_header_ahg(req, tx,
+							       datalen);
+				if (changes < 0)
+					goto free_tx;
+				sdma_txinit_ahg(&tx->txreq,
+						SDMA_TXREQ_F_USE_AHG,
+						datalen, req->ahg_idx, changes,
+						req->ahg, sizeof(req->hdr),
+						user_sdma_txreq_cb);
+			}
+		} else {
+			ret = sdma_txinit(&tx->txreq, 0, sizeof(req->hdr) +
+					  datalen, user_sdma_txreq_cb);
+			if (ret)
+				goto free_tx;
+			/*
+			 * Modify the header for this packet. This only needs
+			 * to be done if we are not going to use AHG. Otherwise,
+			 * the HW will do it based on the changes we gave it
+			 * during sdma_txinit_ahg().
+			 */
+			ret = set_txreq_header(req, tx, datalen);
+			if (ret)
+				goto free_txreq;
+		}
+
+		/*
+		 * If the request contains any data vectors, add up to
+		 * fragsize bytes to the descriptor.
+		 */
+		while (queued < datalen &&
+		       (req->sent + data_sent) < req->data_len) {
+			unsigned long base, offset;
+			unsigned pageidx, len;
+
+			base = (unsigned long)iovec->iov.iov_base;
+			offset = ((base + iovec->offset + iov_offset) &
+				  ~PAGE_MASK);
+			pageidx = (((iovec->offset + iov_offset +
+				     base) - (base & PAGE_MASK)) >> PAGE_SHIFT);
+			len = offset + req->info.fragsize > PAGE_SIZE ?
+				PAGE_SIZE - offset : req->info.fragsize;
+			len = min((datalen - queued), len);
+			ret = sdma_txadd_page(pq->dd, &tx->txreq,
+					      iovec->pages[pageidx],
+					      offset, len);
+			if (ret) {
+				dd_dev_err(pq->dd,
+					   "SDMA txreq add page failed %d\n",
+					   ret);
+				iovec_set_complete(iovec);
+				goto free_txreq;
+			}
+			iov_offset += len;
+			queued += len;
+			data_sent += len;
+			if (unlikely(queued < datalen &&
+				     pageidx == iovec->npages &&
+				     req->iov_idx < req->data_iovs - 1)) {
+				iovec->offset += iov_offset;
+				iovec = &req->iovs[++req->iov_idx];
+				if (!iovec->pages) {
+					ret = pin_vector_pages(req, iovec);
+					if (ret)
+						goto free_txreq;
+				}
+				iov_offset = 0;
+				tx->iovec2 = iovec;
+
+			}
+		}
+		/*
+		 * The txreq was submitted successfully so we can update
+		 * the counters.
+		 */
+		req->koffset += datalen;
+		if (req_opcode(req->info.ctrl) == EXPECTED)
+			req->tidoffset += datalen;
+		req->sent += data_sent;
+		if (req->data_len) {
+			if (tx->iovec1 && !tx->iovec2)
+				tx->iovec1->offset += iov_offset;
+			else if (tx->iovec2)
+				tx->iovec2->offset += iov_offset;
+		}
+		/*
+		 * It is important to increment this here as it is used to
+		 * generate the BTH.PSN and, therefore, can't be bulk-updated
+		 * outside of the loop.
+		 */
+		tx->seqnum = req->seqnum++;
+		list_add_tail(&tx->txreq.list, &req->txps);
+		npkts++;
+	}
+dosend:
+	ret = sdma_send_txlist(req->sde, &pq->busy, &req->txps);
+	if (list_empty(&req->txps))
+		if (req->seqnum == req->info.npkts) {
+			set_bit(SDMA_REQ_SEND_DONE, &req->flags);
+			/*
+			 * The txreq has already been submitted to the HW queue
+			 * so we can free the AHG entry now. Corruption will not
+			 * happen due to the sequential manner in which
+			 * descriptors are processed.
+			 */
+			if (test_bit(SDMA_REQ_HAVE_AHG, &req->flags))
+				sdma_ahg_free(req->sde, req->ahg_idx);
+		}
+	goto done;
+free_txreq:
+	sdma_txclean(pq->dd, &tx->txreq);
+free_tx:
+	kmem_cache_free(pq->txreq_cache, tx);
+done:
+	return ret;
+}
+
+/*
+ * How many pages in this iovec element?
+ */
+static inline int num_user_pages(const struct iovec *iov)
+{
+	const unsigned long addr  = (unsigned long) iov->iov_base;
+	const unsigned long len   = iov->iov_len;
+	const unsigned long spage = addr & PAGE_MASK;
+	const unsigned long epage = (addr + len - 1) & PAGE_MASK;
+
+	return 1 + ((epage - spage) >> PAGE_SHIFT);
+}
+
+static int pin_vector_pages(struct user_sdma_request *req,
+			    struct user_sdma_iovec *iovec) {
+	int ret = 0;
+	unsigned pinned;
+
+	iovec->npages = num_user_pages(&iovec->iov);
+	iovec->pages = kzalloc(sizeof(*iovec->pages) *
+			       iovec->npages, GFP_KERNEL);
+	if (!iovec->pages) {
+		SDMA_DBG(req, "Failed page array alloc");
+		ret = -ENOMEM;
+		goto done;
+	}
+	/* If called by the kernel thread, use the user's mm */
+	if (current->flags & PF_KTHREAD)
+		use_mm(req->user_proc->mm);
+	pinned = get_user_pages_fast(
+		(unsigned long)iovec->iov.iov_base,
+		iovec->npages, 0, iovec->pages);
+	/* If called by the kernel thread, unuse the user's mm */
+	if (current->flags & PF_KTHREAD)
+		unuse_mm(req->user_proc->mm);
+	if (pinned != iovec->npages) {
+		SDMA_DBG(req, "Failed to pin pages (%u/%u)", pinned,
+			 iovec->npages);
+		ret = -EFAULT;
+		goto pfree;
+	}
+	goto done;
+pfree:
+	unpin_vector_pages(iovec);
+done:
+	return ret;
+}
+
+static void unpin_vector_pages(struct user_sdma_iovec *iovec)
+{
+	unsigned i;
+
+	if (ACCESS_ONCE(iovec->offset) != iovec->iov.iov_len) {
+		hfi1_cdbg(SDMA,
+			  "the complete vector has not been sent yet %llu %zu",
+			  iovec->offset, iovec->iov.iov_len);
+		return;
+	}
+	for (i = 0; i < iovec->npages; i++)
+		if (iovec->pages[i])
+			put_page(iovec->pages[i]);
+	kfree(iovec->pages);
+	iovec->pages = NULL;
+	iovec->npages = 0;
+	iovec->offset = 0;
+}
+
+static int check_header_template(struct user_sdma_request *req,
+				 struct hfi1_pkt_header *hdr, u32 lrhlen,
+				 u32 datalen)
+{
+	/*
+	 * Perform safety checks for any type of packet:
+	 *    - transfer size is multiple of 64bytes
+	 *    - packet length is multiple of 4bytes
+	 *    - entire request length is multiple of 4bytes
+	 *    - packet length is not larger than MTU size
+	 *
+	 * These checks are only done for the first packet of the
+	 * transfer since the header is "given" to us by user space.
+	 * For the remainder of the packets we compute the values.
+	 */
+	if (req->info.fragsize % PIO_BLOCK_SIZE ||
+	    lrhlen & 0x3 || req->data_len & 0x3  ||
+	    lrhlen > get_lrh_len(*hdr, req->info.fragsize))
+		return -EINVAL;
+
+	if (req_opcode(req->info.ctrl) == EXPECTED) {
+		/*
+		 * The header is checked only on the first packet. Furthermore,
+		 * we ensure that at least one TID entry is copied when the
+		 * request is submitted. Therefore, we don't have to verify that
+		 * tididx points to something sane.
+		 */
+		u32 tidval = req->tids[req->tididx],
+			tidlen = EXP_TID_GET(tidval, LEN) * PAGE_SIZE,
+			tididx = EXP_TID_GET(tidval, IDX),
+			tidctrl = EXP_TID_GET(tidval, CTRL);
+		__le32 kval = hdr->kdeth.ver_tid_offset;
+		/*
+		 * Expected receive packets have the following
+		 * additional checks:
+		 *     - KDETH.OM is not set
+		 *     - offset is not larger than the TID size
+		 *     - TIDCtrl values match between header and TID array
+		 *     - TID indexes match between header and TID array
+		 */
+		if (KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ||
+		    ((KDETH_GET(kval, OFFSET) * KDETH_OM_SMALL) +
+		     datalen > tidlen) ||
+		    KDETH_GET(kval, TIDCTRL) != tidctrl ||
+		    KDETH_GET(kval, TID) != tididx)
+			return -EINVAL;
+	}
+	return 0;
+}
+
+/*
+ * Correctly set the BTH.PSN field based on type of
+ * transfer - eager packets can just increment the PSN but
+ * expected packets encode generation and sequence in the
+ * BTH.PSN field so just incrementing will result in errors.
+ */
+static inline u32 set_pkt_bth_psn(__be32 bthpsn, u8 expct, u32 frags)
+{
+	u32 val = be32_to_cpu(bthpsn),
+		mask = (HFI1_CAP_IS_KSET(EXTENDED_PSN) ? 0x7fffffffull :
+			0xffffffull),
+		psn = val & mask;
+	if (expct)
+		psn = (psn & ~BTH_SEQ_MASK) | ((psn + frags) & BTH_SEQ_MASK);
+	else
+		psn = psn + frags;
+	return psn & mask;
+}
+
+static int set_txreq_header(struct user_sdma_request *req,
+			    struct user_sdma_txreq *tx, u32 datalen)
+{
+	struct hfi1_user_sdma_pkt_q *pq = req->pq;
+	struct hfi1_pkt_header *hdr = &tx->hdr;
+	u16 pbclen;
+	int ret;
+	u32 tidval = 0, lrhlen = get_lrh_len(*hdr, datalen);
+
+	/* Copy the header template to the request before modification */
+	memcpy(hdr, &req->hdr, sizeof(*hdr));
+
+	/*
+	 * Check if the PBC and LRH length are mismatched. If so
+	 * adjust both in the header.
+	 */
+	pbclen = le16_to_cpu(hdr->pbc[0]);
+	if (PBC2LRH(pbclen) != lrhlen) {
+		pbclen = (pbclen & 0xf000) | LRH2PBC(lrhlen);
+		hdr->pbc[0] = cpu_to_le16(pbclen);
+		hdr->lrh[2] = cpu_to_be16(lrhlen >> 2);
+		/*
+		 * Third packet
+		 * This is the first packet in the sequence that has
+		 * a "static" size that can be used for the rest of
+		 * the packets (besides the last one).
+		 */
+		if (unlikely(req->seqnum == 2)) {
+			/*
+			 * From this point on the lengths in both the
+			 * PBC and LRH are the same until the last
+			 * packet.
+			 * Adjust the template so we don't have to update
+			 * every packet
+			 */
+			req->hdr.pbc[0] = hdr->pbc[0];
+			req->hdr.lrh[2] = hdr->lrh[2];
+		}
+	}
+	/*
+	 * We only have to modify the header if this is not the
+	 * first packet in the request. Otherwise, we use the
+	 * header given to us.
+	 */
+	if (unlikely(!req->seqnum)) {
+		ret = check_header_template(req, hdr, lrhlen, datalen);
+		if (ret)
+			return ret;
+		if (req_opcode(req->info.ctrl) == EXPECTED) {
+			u32 tidlen = EXP_TID_GET(req->tids[req->tididx], LEN) *
+						 PAGE_SIZE;
+			/*
+			 * If the length of the tid is larger than 128K,
+			 * use the large offset multipliers. This needs to be
+			 * checked for every TIDPair.
+			 */
+			req->omfactor = tidlen >= KDETH_OM_MAX_SIZE ?
+				KDETH_OM_LARGE : KDETH_OM_SMALL;
+		}
+		goto done;
+
+	}
+
+	hdr->bth[2] = cpu_to_be32(
+		set_pkt_bth_psn(hdr->bth[2],
+				(req_opcode(req->info.ctrl) == EXPECTED),
+				req->seqnum));
+
+	/* Set ACK request on last packet */
+	if (unlikely(tx->flags & USER_SDMA_TXREQ_FLAGS_LAST_PKT))
+		hdr->bth[2] |= cpu_to_be32(1UL<<31);
+
+	/* Set the new offset */
+	hdr->kdeth.swdata[6] = cpu_to_le32(req->koffset);
+	/* Expected packets have to fill in the new TID information */
+	if (req_opcode(req->info.ctrl) == EXPECTED) {
+		tidval = req->tids[req->tididx];
+		/*
+		 * If the offset puts us at the end of the current TID,
+		 * advance everything.
+		 */
+		if ((req->tidoffset) == (EXP_TID_GET(tidval, LEN) *
+					 PAGE_SIZE)) {
+			u32 tidlen;
+
+			req->tidoffset = 0;
+			/* Since we don't copy all the TIDs, all at once,
+			 * we have to check again. */
+			if (++req->tididx > req->n_tids - 1 ||
+			    !req->tids[req->tididx]) {
+				return -EINVAL;
+			}
+			tidval = req->tids[req->tididx];
+			tidlen = EXP_TID_GET(tidval, LEN) * PAGE_SIZE;
+			req->omfactor = tidlen >= KDETH_OM_MAX_SIZE ?
+				KDETH_OM_LARGE : KDETH_OM_SMALL;
+		}
+		/* Set KDETH.TIDCtrl based on value for this TID. */
+		KDETH_SET(hdr->kdeth.ver_tid_offset, TIDCTRL,
+			  EXP_TID_GET(tidval, CTRL));
+		/* Set KDETH.TID based on value for this TID */
+		KDETH_SET(hdr->kdeth.ver_tid_offset, TID,
+			  EXP_TID_GET(tidval, IDX));
+		/* Clear KDETH.SH only on the last packet */
+		if (unlikely(tx->flags & USER_SDMA_TXREQ_FLAGS_LAST_PKT))
+			KDETH_SET(hdr->kdeth.ver_tid_offset, SH, 0);
+		/*
+		 * Set the KDETH.OFFSET and KDETH.OM based on size of
+		 * transfer.
+		 */
+		KDETH_SET(hdr->kdeth.ver_tid_offset, OFFSET,
+			  req->tidoffset / req->omfactor);
+		KDETH_SET(hdr->kdeth.ver_tid_offset, OM,
+			  ((req->omfactor - KDETH_OM_SMALL) ? 1 : 0));
+	}
+done:
+	trace_hfi1_sdma_user_header(pq->dd, pq->ctxt, pq->subctxt,
+				    req->info.comp_idx, hdr, tidval);
+	return sdma_txadd_kvaddr(pq->dd, &tx->txreq, hdr, sizeof(*hdr));
+}
+
+static int set_txreq_header_ahg(struct user_sdma_request *req,
+				struct user_sdma_txreq *tx, u32 len)
+{
+	int diff = 0;
+	struct hfi1_user_sdma_pkt_q *pq = req->pq;
+	struct hfi1_pkt_header *hdr = &req->hdr;
+	u16 pbclen = le16_to_cpu(hdr->pbc[0]);
+	u32 val32, tidval = 0, lrhlen = get_lrh_len(*hdr, len);
+
+	if (PBC2LRH(pbclen) != lrhlen) {
+		/* PBC.PbcLengthDWs */
+		AHG_HEADER_SET(req->ahg, diff, 0, 0, 12,
+			       cpu_to_le16(LRH2PBC(lrhlen)));
+		/* LRH.PktLen (we need the full 16 bits due to byte swap) */
+		AHG_HEADER_SET(req->ahg, diff, 3, 0, 16,
+			       cpu_to_be16(lrhlen >> 2));
+	}
+
+	/*
+	 * Do the common updates
+	 */
+	/* BTH.PSN and BTH.A */
+	val32 = (be32_to_cpu(hdr->bth[2]) + req->seqnum) &
+		(HFI1_CAP_IS_KSET(EXTENDED_PSN) ? 0x7fffffff : 0xffffff);
+	if (unlikely(tx->flags & USER_SDMA_TXREQ_FLAGS_LAST_PKT))
+		val32 |= 1UL << 31;
+	AHG_HEADER_SET(req->ahg, diff, 6, 0, 16, cpu_to_be16(val32 >> 16));
+	AHG_HEADER_SET(req->ahg, diff, 6, 16, 16, cpu_to_be16(val32 & 0xffff));
+	/* KDETH.Offset */
+	AHG_HEADER_SET(req->ahg, diff, 15, 0, 16,
+		       cpu_to_le16(req->koffset & 0xffff));
+	AHG_HEADER_SET(req->ahg, diff, 15, 16, 16,
+		       cpu_to_le16(req->koffset >> 16));
+	if (req_opcode(req->info.ctrl) == EXPECTED) {
+		__le16 val;
+
+		tidval = req->tids[req->tididx];
+
+		/*
+		 * If the offset puts us at the end of the current TID,
+		 * advance everything.
+		 */
+		if ((req->tidoffset) == (EXP_TID_GET(tidval, LEN) *
+					 PAGE_SIZE)) {
+			req->tidoffset = 0;
+			/* Since we don't copy all the TIDs, all at once,
+			 * we have to check again. */
+			if (++req->tididx > req->n_tids - 1 ||
+			    !req->tids[req->tididx]) {
+				return -EINVAL;
+			}
+			tidval = req->tids[req->tididx];
+		}
+		req->omfactor = ((EXP_TID_GET(tidval, LEN) *
+				  PAGE_SIZE) >=
+				 KDETH_OM_MAX_SIZE) ? KDETH_OM_LARGE :
+			KDETH_OM_SMALL;
+		/* KDETH.OM and KDETH.OFFSET (TID) */
+		AHG_HEADER_SET(req->ahg, diff, 7, 0, 16,
+			       ((!!(req->omfactor - KDETH_OM_SMALL)) << 15 |
+				((req->tidoffset / req->omfactor) & 0x7fff)));
+		/* KDETH.TIDCtrl, KDETH.TID */
+		val = cpu_to_le16(((EXP_TID_GET(tidval, CTRL) & 0x3) << 10) |
+					(EXP_TID_GET(tidval, IDX) & 0x3ff));
+		/* Clear KDETH.SH on last packet */
+		if (unlikely(tx->flags & USER_SDMA_TXREQ_FLAGS_LAST_PKT)) {
+			val |= cpu_to_le16(KDETH_GET(hdr->kdeth.ver_tid_offset,
+								INTR) >> 16);
+			val &= cpu_to_le16(~(1U << 13));
+			AHG_HEADER_SET(req->ahg, diff, 7, 16, 14, val);
+		} else
+			AHG_HEADER_SET(req->ahg, diff, 7, 16, 12, val);
+	}
+
+	trace_hfi1_sdma_user_header_ahg(pq->dd, pq->ctxt, pq->subctxt,
+					req->info.comp_idx, req->sde->this_idx,
+					req->ahg_idx, req->ahg, diff, tidval);
+	return diff;
+}
+
+static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status,
+			       int drain)
+{
+	struct user_sdma_txreq *tx =
+		container_of(txreq, struct user_sdma_txreq, txreq);
+	struct user_sdma_request *req = tx->req;
+	struct hfi1_user_sdma_pkt_q *pq = req ? req->pq : NULL;
+	u64 tx_seqnum;
+
+	if (unlikely(!req || !pq))
+		return;
+
+	if (tx->iovec1)
+		iovec_may_free(tx->iovec1, unpin_vector_pages);
+	if (tx->iovec2)
+		iovec_may_free(tx->iovec2, unpin_vector_pages);
+
+	tx_seqnum = tx->seqnum;
+	kmem_cache_free(pq->txreq_cache, tx);
+
+	if (status != SDMA_TXREQ_S_OK) {
+		dd_dev_err(pq->dd, "SDMA completion with error %d", status);
+		set_comp_state(req, ERROR, status);
+		set_bit(SDMA_REQ_HAS_ERROR, &req->flags);
+		/* Do not free the request until the sender loop has ack'ed
+		 * the error and we've seen all txreqs. */
+		if (tx_seqnum == ACCESS_ONCE(req->seqnum) &&
+		    test_bit(SDMA_REQ_DONE_ERROR, &req->flags)) {
+			atomic_dec(&pq->n_reqs);
+			user_sdma_free_request(req);
+		}
+	} else {
+		if (tx_seqnum == req->info.npkts - 1) {
+			/* We've sent and completed all packets in this
+			 * request. Signal completion to the user */
+			atomic_dec(&pq->n_reqs);
+			set_comp_state(req, COMPLETE, 0);
+			user_sdma_free_request(req);
+		}
+	}
+	if (!atomic_read(&pq->n_reqs))
+		xchg(&pq->state, SDMA_PKT_Q_INACTIVE);
+}
+
+static void user_sdma_free_request(struct user_sdma_request *req)
+{
+	if (!list_empty(&req->txps)) {
+		struct sdma_txreq *t, *p;
+
+		list_for_each_entry_safe(t, p, &req->txps, list) {
+			struct user_sdma_txreq *tx =
+				container_of(t, struct user_sdma_txreq, txreq);
+			list_del_init(&t->list);
+			sdma_txclean(req->pq->dd, t);
+			kmem_cache_free(req->pq->txreq_cache, tx);
+		}
+	}
+	if (req->data_iovs) {
+		int i;
+
+		for (i = 0; i < req->data_iovs; i++)
+			if (req->iovs[i].npages && req->iovs[i].pages)
+				unpin_vector_pages(&req->iovs[i]);
+	}
+	if (req->user_proc)
+		put_task_struct(req->user_proc);
+	kfree(req->tids);
+	clear_bit(SDMA_REQ_IN_USE, &req->flags);
+}
+
+static inline void set_comp_state(struct user_sdma_request *req,
+					enum hfi1_sdma_comp_state state,
+					int ret)
+{
+	SDMA_DBG(req, "Setting completion status %u %d", state, ret);
+	req->cq->comps[req->info.comp_idx].status = state;
+	if (state == ERROR)
+		req->cq->comps[req->info.comp_idx].errcode = -ret;
+	trace_hfi1_sdma_user_completion(req->pq->dd, req->pq->ctxt,
+					req->pq->subctxt, req->info.comp_idx,
+					state, ret);
+}
diff --git a/drivers/infiniband/hw/hfi1/user_sdma.h b/drivers/infiniband/hw/hfi1/user_sdma.h
new file mode 100644
index 0000000..fa44225
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/user_sdma.h
@@ -0,0 +1,89 @@
+/*
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+#include <linux/device.h>
+#include <linux/wait.h>
+
+#include "common.h"
+#include "iowait.h"
+
+#define EXP_TID_TIDLEN_MASK   0x7FFULL
+#define EXP_TID_TIDLEN_SHIFT  0
+#define EXP_TID_TIDCTRL_MASK  0x3ULL
+#define EXP_TID_TIDCTRL_SHIFT 20
+#define EXP_TID_TIDIDX_MASK   0x7FFULL
+#define EXP_TID_TIDIDX_SHIFT  22
+#define EXP_TID_GET(tid, field)	\
+	(((tid) >> EXP_TID_TID##field##_SHIFT) & EXP_TID_TID##field##_MASK)
+
+extern uint extended_psn;
+
+struct hfi1_user_sdma_pkt_q {
+	struct list_head list;
+	unsigned ctxt;
+	unsigned subctxt;
+	u16 n_max_reqs;
+	atomic_t n_reqs;
+	u16 reqidx;
+	struct hfi1_devdata *dd;
+	struct kmem_cache *txreq_cache;
+	struct user_sdma_request *reqs;
+	struct iowait busy;
+	unsigned state;
+};
+
+struct hfi1_user_sdma_comp_q {
+	u16 nentries;
+	struct hfi1_sdma_comp_entry *comps;
+};
+
+int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *, struct file *);
+int hfi1_user_sdma_free_queues(struct hfi1_filedata *);
+int hfi1_user_sdma_process_request(struct file *, struct iovec *, unsigned long,
+				   unsigned long *);
