IB/hfi1: Move driver out of staging

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

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

1 files changed, 1625 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c
new file mode 100644
index 000000000000..29f4795f866c
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/user_sdma.c
@@ -0,0 +1,1625 @@
+/*
+ * Copyright(c) 2015, 2016 Intel Corporation.
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *  - Neither the name of Intel Corporation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+#include <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 <linux/vmalloc.h>
+
+#include "hfi.h"
+#include "sdma.h"
+#include "user_sdma.h"
+#include "verbs.h"  /* for the headers */
+#include "common.h" /* for struct hfi1_tid_info */
+#include "trace.h"
+#include "mmu_rb.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 TXREQ_FLAGS_REQ_LAST_PKT BIT(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 BIT(0)
+#define SDMA_PKT_Q_ACTIVE   BIT(1)
+#define SDMA_PKT_Q_DEFERRED BIT(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 sdma_mmu_node;
+
+struct user_sdma_iovec {
+	struct list_head list;
+	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 sdma_mmu_node *node;
+};
+
+#define SDMA_CACHE_NODE_EVICT BIT(0)
+
+struct sdma_mmu_node {
+	struct mmu_rb_node rb;
+	struct list_head list;
+	struct hfi1_user_sdma_pkt_q *pq;
+	atomic_t refcount;
+	struct page **pages;
+	unsigned npages;
+	unsigned long flags;
+};
+
+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;
+	/*
+	 * 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 */
+	u16 n_tids;
+	/* TID array values copied from the tid_iov vector */
+	u32 *tids;
+	u16 tididx;
+	u32 sent;
+	u64 seqnum;
+	u64 seqcomp;
+	u64 seqsubmitted;
+	struct list_head txps;
+	unsigned long flags;
+	/* status of the last txreq completed */
+	int status;
+};
+
+/*
+ * A single txreq could span up to 3 physical pages when the MTU
+ * is sufficiently large (> 4K). Each of the IOV pointers also
+ * needs it's own set of flags so the vector has been handled
+ * independently of each other.
+ */
+struct user_sdma_txreq {
+	/* Packet header for the txreq */
+	struct hfi1_pkt_header hdr;
+	struct sdma_txreq txreq;
+	struct list_head list;
+	struct user_sdma_request *req;
+	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);
+static inline void pq_update(struct hfi1_user_sdma_pkt_q *);
+static void user_sdma_free_request(struct user_sdma_request *, bool);
+static int pin_vector_pages(struct user_sdma_request *,
+			    struct user_sdma_iovec *);
+static void unpin_vector_pages(struct mm_struct *, struct page **, unsigned,
+			       unsigned);
+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 hfi1_user_sdma_pkt_q *,
+				  struct hfi1_user_sdma_comp_q *,
+				  u16, 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 bool sdma_rb_filter(struct mmu_rb_node *, unsigned long, unsigned long);
+static int sdma_rb_insert(struct rb_root *, struct mmu_rb_node *);
+static void sdma_rb_remove(struct rb_root *, struct mmu_rb_node *,
+			   struct mm_struct *);
+static int sdma_rb_invalidate(struct rb_root *, struct mmu_rb_node *);
+
+static struct mmu_rb_ops sdma_rb_ops = {
+	.filter = sdma_rb_filter,
+	.insert = sdma_rb_insert,
+	.remove = sdma_rb_remove,
+	.invalidate = sdma_rb_invalidate
+};
+
+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);
+	write_seqlock(&dev->iowait_lock);
+	if (list_empty(&pq->busy.list))
+		list_add_tail(&pq->busy.list, &sde->dmawait);
+	write_sequnlock(&dev->iowait_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 = obj;
+
+	memset(tx, 0, sizeof(*tx));
+}
+
+int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt, struct file *fp)
+{
+	struct hfi1_filedata *fd;
+	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;
+	}
+
+	fd = fp->private_data;
+
+	if (!hfi1_sdma_comp_ring_size) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	dd = uctxt->dd;
+
+	pq = kzalloc(sizeof(*pq), GFP_KERNEL);
+	if (!pq)
+		goto pq_nomem;
+
+	memsize = sizeof(*pq->reqs) * hfi1_sdma_comp_ring_size;
+	pq->reqs = kzalloc(memsize, GFP_KERNEL);
+	if (!pq->reqs)
+		goto pq_reqs_nomem;
+
+	INIT_LIST_HEAD(&pq->list);
+	pq->dd = dd;
+	pq->ctxt = uctxt->ctxt;
+	pq->subctxt = fd->subctxt;
+	pq->n_max_reqs = hfi1_sdma_comp_ring_size;
+	pq->state = SDMA_PKT_Q_INACTIVE;
+	atomic_set(&pq->n_reqs, 0);
+	init_waitqueue_head(&pq->wait);
+	pq->sdma_rb_root = RB_ROOT;
+	INIT_LIST_HEAD(&pq->evict);
+	spin_lock_init(&pq->evict_lock);
+
+	iowait_init(&pq->busy, 0, NULL, defer_packet_queue,
+		    activate_packet_queue, NULL);
+	pq->reqidx = 0;
+	snprintf(buf, 64, "txreq-kmem-cache-%u-%u-%u", dd->unit, uctxt->ctxt,
+		 fd->subctxt);
+	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;
+	}
+	fd->pq = pq;
+	cq = kzalloc(sizeof(*cq), GFP_KERNEL);
+	if (!cq)
+		goto cq_nomem;
+
+	memsize = PAGE_ALIGN(sizeof(*cq->comps) * hfi1_sdma_comp_ring_size);
+	cq->comps = vmalloc_user(memsize);
+	if (!cq->comps)
+		goto cq_comps_nomem;
+
+	cq->nentries = hfi1_sdma_comp_ring_size;
+	fd->cq = cq;
+
+	ret = hfi1_mmu_rb_register(&pq->sdma_rb_root, &sdma_rb_ops);
+	if (ret) {
+		dd_dev_err(dd, "Failed to register with MMU %d", ret);
+		goto done;
+	}
+
+	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);
+	fd->pq = 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;
+	hfi1_mmu_rb_unregister(&pq->sdma_rb_root);
+	if (pq) {
+		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);
+		/* Wait until all requests have been freed. */
+		wait_event_interruptible(
+			pq->wait,
+			(ACCESS_ONCE(pq->state) == SDMA_PKT_Q_INACTIVE));
+		kfree(pq->reqs);
+		kmem_cache_destroy(pq->txreq_cache);
+		kfree(pq);
+		fd->pq = NULL;
+	}
+	if (fd->cq) {
+		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;
+	struct hfi1_filedata *fd = fp->private_data;
+	struct hfi1_ctxtdata *uctxt = fd->uctxt;
+	struct hfi1_user_sdma_pkt_q *pq = fd->pq;
+	struct hfi1_user_sdma_comp_q *cq = fd->cq;
+	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;
+	int req_queued = 0;
+
+	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, fd->subctxt,
+		   iovec[idx].iov_len, sizeof(info) + sizeof(req->hdr));
+		return -EINVAL;
+	}
+	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, fd->subctxt, ret);
+		return -EFAULT;
+	}
+
+	trace_hfi1_sdma_user_reqinfo(dd, uctxt->ctxt, fd->subctxt,
+				     (u16 *)&info);
+	if (cq->comps[info.comp_idx].status == QUEUED ||
+	    test_bit(SDMA_REQ_IN_USE, &pq->reqs[info.comp_idx].flags)) {
+		hfi1_cdbg(SDMA, "[%u:%u:%u] Entry %u is in QUEUED state",
+			  dd->unit, uctxt->ctxt, fd->subctxt,
+			  info.comp_idx);
+		return -EBADSLT;
+	}
+	if (!info.fragsize) {
+		hfi1_cdbg(SDMA,
+			  "[%u:%u:%u:%u] Request does not specify fragsize",
+			  dd->unit, uctxt->ctxt, fd->subctxt, info.comp_idx);
+		return -EINVAL;
+	}
+	/*
+	 * 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, fd->subctxt, 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;
+	req->status = -1;
+	INIT_LIST_HEAD(&req->txps);
+
+	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);
+		return -EINVAL;
+	}
+	/* 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 >= 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;
+	}
+
+	/* Checking P_KEY for requests from user-space */
+	if (egress_pkey_check(dd->pport, req->hdr.lrh, req->hdr.bth, sc,
+			      PKEY_CHECK_INVALID)) {
+		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]);
+	/*
+	 * Calculate the initial TID offset based on the values of
+	 * KDETH.OFFSET and KDETH.OM that are passed in.
+	 */
+	req->tidoffset = KDETH_GET(req->hdr.kdeth.ver_tid_offset, OFFSET) *
+		(KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ?
+		 KDETH_OM_LARGE : KDETH_OM_SMALL);
+	SDMA_DBG(req, "Initial TID offset %u", req->tidoffset);
+	idx++;
+
+	/* Save all the IO vector structures */
+	while (i < req->data_iovs) {
+		INIT_LIST_HEAD(&req->iovs[i].list);
+		memcpy(&req->iovs[i].iov, iovec + idx++, sizeof(struct iovec));
+		ret = pin_vector_pages(req, &req->iovs[i]);
+		if (ret) {
+			req->status = ret;
+			goto free_req;
+		}
+		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 + fd->subctxt),
+					 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(pq, cq, info.comp_idx, QUEUED, 0);
+	atomic_inc(&pq->n_reqs);
+	req_queued = 1;
+	/* Send the first N packets in the request to buy us some time */
+	ret = user_sdma_send_pkts(req, pcount);
+	if (unlikely(ret < 0 && ret != -EBUSY)) {
+		req->status = ret;
+		goto free_req;
+	}
+
+	/*
+	 * It is possible that the SDMA engine would have processed all the
+	 * submitted packets by the time we get here. Therefore, only set
+	 * packet queue state to ACTIVE if there are still uncompleted
+	 * requests.
+	 */
+	if (atomic_read(&pq->n_reqs))
+		xchg(&pq->state, SDMA_PKT_Q_ACTIVE);
+
+	/*
+	 * 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) {
+				req->status = ret;
+				set_bit(SDMA_REQ_DONE_ERROR, &req->flags);
+				if (ACCESS_ONCE(req->seqcomp) ==
+				    req->seqsubmitted - 1)
+					goto free_req;
+				return ret;
+			}
+			wait_event_interruptible_timeout(
+				pq->busy.wait_dma,
+				(pq->state == SDMA_PKT_Q_ACTIVE),
+				msecs_to_jiffies(
+					SDMA_IOWAIT_TIMEOUT));
+		}
+	}
+	*count += idx;
+	return 0;
+free_req:
+	user_sdma_free_request(req, true);
+	if (req_queued)
+		pq_update(pq);
+	set_comp_state(pq, cq, info.comp_idx, ERROR, req->status);
+	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;
+		/*
+		 * Get the data length based on the remaining space in the
+		 * TID pair.
+		 */
+		len = min(tidlen - req->tidoffset, (u32)req->info.fragsize);
+		/* If we've filled up the TID pair, move to the next one. */
+		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);
+		}
+		/*
+		 * Since the TID pairs map entire pages, make sure that we
+		 * are not going to try to send more data that we have
+		 * remaining.
+		 */
+		len = min(len, req->data_len - req->sent);
+	} 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)
+		return -EINVAL;
+
+	pq = req->pq;
+
+	/* If tx completion has reported an error, we are done. */
+	if (test_bit(SDMA_REQ_HAS_ERROR, &req->flags)) {
+		set_bit(SDMA_REQ_DONE_ERROR, &req->flags);
+		return -EFAULT;
+	}
+
+	/*
+	 * Check if we might have sent the entire request already
+	 */
+	if (unlikely(req->seqnum == req->info.npkts)) {
+		if (!list_empty(&req->txps))
+			goto dosend;
+		return ret;
+	}
+
+	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);
+			return -EFAULT;
+		}
+
+		tx = kmem_cache_alloc(pq->txreq_cache, GFP_KERNEL);
+		if (!tx)
+			return -ENOMEM;
+
+		tx->flags = 0;
+		tx->req = req;
+		tx->busycount = 0;
+		INIT_LIST_HEAD(&tx->list);
+
+		if (req->seqnum == req->info.npkts - 1)
+			tx->flags |= TXREQ_FLAGS_REQ_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];
+				WARN_ON(iovec->offset);
+			}
+
+			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 = offset_in_page(base + iovec->offset +
+						iov_offset);
+			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) {
+				SDMA_DBG(req, "SDMA txreq add page failed %d\n",
+					 ret);
+				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];
+				iov_offset = 0;
+			}
+		}
+		/*
+		 * 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)
+			iovec->offset += iov_offset;
+		list_add_tail(&tx->txreq.list, &req->txps);
+		/*
+		 * 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++;
+		npkts++;
+	}
+dosend:
+	ret = sdma_send_txlist(req->sde, &pq->busy, &req->txps);
+	if (list_empty(&req->txps)) {
+		req->seqsubmitted = req->seqnum;
+		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);
+		}
+	} else if (ret > 0) {
+		req->seqsubmitted += ret;
+		ret = 0;
+	}
+	return ret;
+
+free_txreq:
+	sdma_txclean(pq->dd, &tx->txreq);
+free_tx:
+	kmem_cache_free(pq->txreq_cache, tx);
+	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 u32 sdma_cache_evict(struct hfi1_user_sdma_pkt_q *pq, u32 npages)
+{
+	u32 cleared = 0;
+	struct sdma_mmu_node *node, *ptr;
+	struct list_head to_evict = LIST_HEAD_INIT(to_evict);
+
+	spin_lock(&pq->evict_lock);
+	list_for_each_entry_safe_reverse(node, ptr, &pq->evict, list) {
+		/* Make sure that no one is still using the node. */
+		if (!atomic_read(&node->refcount)) {
+			set_bit(SDMA_CACHE_NODE_EVICT, &node->flags);
+			list_del_init(&node->list);
+			list_add(&node->list, &to_evict);
+			cleared += node->npages;
+			if (cleared >= npages)
+				break;
+		}
+	}
+	spin_unlock(&pq->evict_lock);
+
+	list_for_each_entry_safe(node, ptr, &to_evict, list)
+		hfi1_mmu_rb_remove(&pq->sdma_rb_root, &node->rb);
+
+	return cleared;
+}
+
+static int pin_vector_pages(struct user_sdma_request *req,
+			    struct user_sdma_iovec *iovec) {
+	int ret = 0, pinned, npages, cleared;
+	struct page **pages;
+	struct hfi1_user_sdma_pkt_q *pq = req->pq;
+	struct sdma_mmu_node *node = NULL;
+	struct mmu_rb_node *rb_node;
+
+	rb_node = hfi1_mmu_rb_extract(&pq->sdma_rb_root,
+				      (unsigned long)iovec->iov.iov_base,
+				      iovec->iov.iov_len);
+	if (rb_node && !IS_ERR(rb_node))
+		node = container_of(rb_node, struct sdma_mmu_node, rb);
+	else
+		rb_node = NULL;
+
+	if (!node) {
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
+		if (!node)
+			return -ENOMEM;
+
+		node->rb.addr = (unsigned long)iovec->iov.iov_base;
+		node->pq = pq;
+		atomic_set(&node->refcount, 0);
+		INIT_LIST_HEAD(&node->list);
+	}
+
+	npages = num_user_pages(&iovec->iov);
+	if (node->npages < npages) {
+		pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL);
+		if (!pages) {
+			SDMA_DBG(req, "Failed page array alloc");
+			ret = -ENOMEM;
+			goto bail;
+		}
+		memcpy(pages, node->pages, node->npages * sizeof(*pages));
+
+		npages -= node->npages;
+
+		/*
+		 * If rb_node is NULL, it means that this is brand new node
+		 * and, therefore not on the eviction list.
+		 * If, however, the rb_node is non-NULL, it means that the
+		 * node is already in RB tree and, therefore on the eviction
+		 * list (nodes are unconditionally inserted in the eviction
+		 * list). In that case, we have to remove the node prior to
+		 * calling the eviction function in order to prevent it from
+		 * freeing this node.
+		 */
+		if (rb_node) {
+			spin_lock(&pq->evict_lock);
+			list_del_init(&node->list);
+			spin_unlock(&pq->evict_lock);
+		}
+retry:
+		if (!hfi1_can_pin_pages(pq->dd, pq->n_locked, npages)) {
+			cleared = sdma_cache_evict(pq, npages);
+			if (cleared >= npages)
+				goto retry;
+		}
+		pinned = hfi1_acquire_user_pages(
+			((unsigned long)iovec->iov.iov_base +
+			 (node->npages * PAGE_SIZE)), npages, 0,
+			pages + node->npages);
+		if (pinned < 0) {
+			kfree(pages);
+			ret = pinned;
+			goto bail;
+		}
+		if (pinned != npages) {
+			unpin_vector_pages(current->mm, pages, node->npages,
+					   pinned);
+			ret = -EFAULT;
+			goto bail;
+		}
+		kfree(node->pages);
+		node->rb.len = iovec->iov.iov_len;
+		node->pages = pages;
+		node->npages += pinned;
+		npages = node->npages;
+		spin_lock(&pq->evict_lock);
+		list_add(&node->list, &pq->evict);
+		pq->n_locked += pinned;
+		spin_unlock(&pq->evict_lock);
+	}
+	iovec->pages = node->pages;
+	iovec->npages = npages;
+	iovec->node = node;
+
+	ret = hfi1_mmu_rb_insert(&req->pq->sdma_rb_root, &node->rb);
+	if (ret) {
+		spin_lock(&pq->evict_lock);
+		if (!list_empty(&node->list))
+			list_del(&node->list);
+		pq->n_locked -= node->npages;
+		spin_unlock(&pq->evict_lock);
+		goto bail;
+	}
+	return 0;
+bail:
+	if (rb_node)
+		unpin_vector_pages(current->mm, node->pages, 0, node->npages);
+	kfree(node);
+	return ret;
+}
+
+static void unpin_vector_pages(struct mm_struct *mm, struct page **pages,
+			       unsigned start, unsigned npages)
+{
+	hfi1_release_user_pages(mm, pages + start, npages, 0);
+	kfree(pages);
+}
+
+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),
+			tidoff;
+		__le32 kval = hdr->kdeth.ver_tid_offset;
+
+		tidoff = KDETH_GET(kval, OFFSET) *
+			  (KDETH_GET(req->hdr.kdeth.ver_tid_offset, OM) ?
+			   KDETH_OM_LARGE : KDETH_OM_SMALL);
+		/*
+		 * Expected receive packets have the following
+		 * additional checks:
+		 *     - 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 ((tidoff + 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;
+		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 & TXREQ_FLAGS_REQ_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)) {
+			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;
+		/* 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 & TXREQ_FLAGS_REQ_LAST_PKT))
+			KDETH_SET(hdr->kdeth.ver_tid_offset, SH, 0);
+		/*
+		 * Set the KDETH.OFFSET and KDETH.OM based on size of
+		 * transfer.
+		 */
+		SDMA_DBG(req, "TID offset %ubytes %uunits om%u",
+			 req->tidoffset, req->tidoffset / req->omfactor,
+			 !!(req->omfactor - KDETH_OM_SMALL));
+		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));
+	}
+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 & TXREQ_FLAGS_REQ_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 & TXREQ_FLAGS_REQ_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;
+}
+
+/*
+ * SDMA tx request completion callback. Called when the SDMA progress
+ * state machine gets notification that the SDMA descriptors for this
+ * tx request have been processed by the DMA engine. Called in
+ * interrupt context.
+ */
+static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status)
+{
+	struct user_sdma_txreq *tx =
+		container_of(txreq, struct user_sdma_txreq, txreq);
+	struct user_sdma_request *req;
+	struct hfi1_user_sdma_pkt_q *pq;
+	struct hfi1_user_sdma_comp_q *cq;
+	u16 idx;
+
+	if (!tx->req)
+		return;
+
+	req = tx->req;
+	pq = req->pq;
+	cq = req->cq;
+
+	if (status != SDMA_TXREQ_S_OK) {
+		SDMA_DBG(req, "SDMA completion with error %d",
+			 status);
+		set_bit(SDMA_REQ_HAS_ERROR, &req->flags);
+	}
+
+	req->seqcomp = tx->seqnum;
+	kmem_cache_free(pq->txreq_cache, tx);
+	tx = NULL;
+
+	idx = req->info.comp_idx;
+	if (req->status == -1 && status == SDMA_TXREQ_S_OK) {
+		if (req->seqcomp == req->info.npkts - 1) {
+			req->status = 0;
+			user_sdma_free_request(req, false);
+			pq_update(pq);
+			set_comp_state(pq, cq, idx, COMPLETE, 0);
+		}
+	} else {
+		if (status != SDMA_TXREQ_S_OK)
+			req->status = status;
+		if (req->seqcomp == (ACCESS_ONCE(req->seqsubmitted) - 1) &&
+		    (test_bit(SDMA_REQ_SEND_DONE, &req->flags) ||
+		     test_bit(SDMA_REQ_DONE_ERROR, &req->flags))) {
+			user_sdma_free_request(req, false);
+			pq_update(pq);
+			set_comp_state(pq, cq, idx, ERROR, req->status);
+		}
+	}
+}
+
+static inline void pq_update(struct hfi1_user_sdma_pkt_q *pq)
+{
+	if (atomic_dec_and_test(&pq->n_reqs)) {
+		xchg(&pq->state, SDMA_PKT_Q_INACTIVE);
+		wake_up(&pq->wait);
+	}
+}
+
+static void user_sdma_free_request(struct user_sdma_request *req, bool unpin)
+{
+	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) {
+		struct sdma_mmu_node *node;
+		int i;
+
+		for (i = 0; i < req->data_iovs; i++) {
+			node = req->iovs[i].node;
+			if (!node)
+				continue;
+
+			if (unpin)
+				hfi1_mmu_rb_remove(&req->pq->sdma_rb_root,
+						   &node->rb);
+			else
+				atomic_dec(&node->refcount);
+		}
+	}
+	kfree(req->tids);
+	clear_bit(SDMA_REQ_IN_USE, &req->flags);
+}
+
+static inline void set_comp_state(struct hfi1_user_sdma_pkt_q *pq,
+				  struct hfi1_user_sdma_comp_q *cq,
+				  u16 idx, enum hfi1_sdma_comp_state state,
+				  int ret)
+{
+	hfi1_cdbg(SDMA, "[%u:%u:%u:%u] Setting completion status %u %d",
+		  pq->dd->unit, pq->ctxt, pq->subctxt, idx, state, ret);
+	cq->comps[idx].status = state;
+	if (state == ERROR)
+		cq->comps[idx].errcode = -ret;
+	trace_hfi1_sdma_user_completion(pq->dd, pq->ctxt, pq->subctxt,
+					idx, state, ret);
+}
+
+static bool sdma_rb_filter(struct mmu_rb_node *node, unsigned long addr,
+			   unsigned long len)
+{
+	return (bool)(node->addr == addr);
+}
+
+static int sdma_rb_insert(struct rb_root *root, struct mmu_rb_node *mnode)
+{
+	struct sdma_mmu_node *node =
+		container_of(mnode, struct sdma_mmu_node, rb);
+
+	atomic_inc(&node->refcount);
+	return 0;
+}
+
+static void sdma_rb_remove(struct rb_root *root, struct mmu_rb_node *mnode,
+			   struct mm_struct *mm)
+{
+	struct sdma_mmu_node *node =
+		container_of(mnode, struct sdma_mmu_node, rb);
+
+	spin_lock(&node->pq->evict_lock);
+	/*
+	 * We've been called by the MMU notifier but this node has been
+	 * scheduled for eviction. The eviction function will take care
+	 * of freeing this node.
+	 * We have to take the above lock first because we are racing
+	 * against the setting of the bit in the eviction function.
+	 */
+	if (mm && test_bit(SDMA_CACHE_NODE_EVICT, &node->flags)) {
+		spin_unlock(&node->pq->evict_lock);
+		return;
+	}
+
+	if (!list_empty(&node->list))
+		list_del(&node->list);
+	node->pq->n_locked -= node->npages;
+	spin_unlock(&node->pq->evict_lock);
+
+	/*
+	 * If mm is set, we are being called by the MMU notifier and we
+	 * should not pass a mm_struct to unpin_vector_page(). This is to
+	 * prevent a deadlock when hfi1_release_user_pages() attempts to
+	 * take the mmap_sem, which the MMU notifier has already taken.
+	 */
+	unpin_vector_pages(mm ? NULL : current->mm, node->pages, 0,
+			   node->npages);
+	/*
+	 * If called by the MMU notifier, we have to adjust the pinned
+	 * page count ourselves.
+	 */
+	if (mm)
+		mm->pinned_vm -= node->npages;
+	kfree(node);
+}
+
+static int sdma_rb_invalidate(struct rb_root *root, struct mmu_rb_node *mnode)
+{
+	struct sdma_mmu_node *node =
+		container_of(mnode, struct sdma_mmu_node, rb);
+
+	if (!atomic_read(&node->refcount))
+		return 1;
+	return 0;
+}