1 files changed, 291 insertions, 325 deletions

diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c
index 7827baf455a1..6efcb79c8efe 100644
--- a/drivers/infiniband/ulp/iser/iser_memory.c
+++ b/drivers/infiniband/ulp/iser/iser_memory.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
- * Copyright (c) 2013 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -30,7 +30,6 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
-#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
@@ -39,387 +38,354 @@
 
 #include "iscsi_iser.h"
 
-#define ISER_KMALLOC_THRESHOLD 0x20000 /* 128K - kmalloc limit */
-
-/**
- * iser_start_rdma_unaligned_sg
- */
-static int iser_start_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,
-					enum iser_data_dir cmd_dir)
+void iser_reg_comp(struct ib_cq *cq, struct ib_wc *wc)
 {
-	int dma_nents;
-	struct ib_device *dev;
-	char *mem = NULL;
-	struct iser_data_buf *data = &iser_task->data[cmd_dir];
-	unsigned long  cmd_data_len = data->data_len;
-
-	if (cmd_data_len > ISER_KMALLOC_THRESHOLD)
-		mem = (void *)__get_free_pages(GFP_ATOMIC,
-		      ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT);
-	else
-		mem = kmalloc(cmd_data_len, GFP_ATOMIC);
-
-	if (mem == NULL) {
-		iser_err("Failed to allocate mem size %d %d for copying sglist\n",
-			 data->size,(int)cmd_data_len);
-		return -ENOMEM;
-	}
+	iser_err_comp(wc, "memreg");
+}
 
-	if (cmd_dir == ISER_DIR_OUT) {
-		/* copy the unaligned sg the buffer which is used for RDMA */
-		struct scatterlist *sgl = (struct scatterlist *)data->buf;
-		struct scatterlist *sg;
-		int i;
-		char *p, *from;
-
-		p = mem;
-		for_each_sg(sgl, sg, data->size, i) {
-			from = kmap_atomic(sg_page(sg));
-			memcpy(p,
-			       from + sg->offset,
-			       sg->length);
-			kunmap_atomic(from);
-			p += sg->length;
-		}
-	}
+static struct iser_fr_desc *iser_reg_desc_get_fr(struct ib_conn *ib_conn)
+{
+	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
+	struct iser_fr_desc *desc;
+	unsigned long flags;
 
-	sg_init_one(&iser_task->data_copy[cmd_dir].sg_single, mem, cmd_data_len);
-	iser_task->data_copy[cmd_dir].buf  =
-		&iser_task->data_copy[cmd_dir].sg_single;
-	iser_task->data_copy[cmd_dir].size = 1;
+	spin_lock_irqsave(&fr_pool->lock, flags);
+	desc = list_first_entry(&fr_pool->list,
+				struct iser_fr_desc, list);
+	list_del(&desc->list);
+	spin_unlock_irqrestore(&fr_pool->lock, flags);
 
-	iser_task->data_copy[cmd_dir].copy_buf  = mem;
+	return desc;
+}
 
-	dev = iser_task->iser_conn->ib_conn->device->ib_device;
-	dma_nents = ib_dma_map_sg(dev,
-				  &iser_task->data_copy[cmd_dir].sg_single,
-				  1,
-				  (cmd_dir == ISER_DIR_OUT) ?
-				  DMA_TO_DEVICE : DMA_FROM_DEVICE);
-	BUG_ON(dma_nents == 0);
+static void iser_reg_desc_put_fr(struct ib_conn *ib_conn,
+				 struct iser_fr_desc *desc)
+{
+	struct iser_fr_pool *fr_pool = &ib_conn->fr_pool;
+	unsigned long flags;
 
-	iser_task->data_copy[cmd_dir].dma_nents = dma_nents;
-	return 0;
+	spin_lock_irqsave(&fr_pool->lock, flags);
+	list_add(&desc->list, &fr_pool->list);
+	spin_unlock_irqrestore(&fr_pool->lock, flags);
 }
 
-/**
- * iser_finalize_rdma_unaligned_sg
- */
-void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *iser_task,
-				     enum iser_data_dir         cmd_dir)
+int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
+			   enum iser_data_dir iser_dir,
+			   enum dma_data_direction dma_dir)
 {
+	struct iser_data_buf *data = &iser_task->data[iser_dir];
 	struct ib_device *dev;
-	struct iser_data_buf *mem_copy;
-	unsigned long  cmd_data_len;
-
-	dev = iser_task->iser_conn->ib_conn->device->ib_device;
-	mem_copy = &iser_task->data_copy[cmd_dir];
-
-	ib_dma_unmap_sg(dev, &mem_copy->sg_single, 1,
-			(cmd_dir == ISER_DIR_OUT) ?
-			DMA_TO_DEVICE : DMA_FROM_DEVICE);
-
-	if (cmd_dir == ISER_DIR_IN) {
-		char *mem;
-		struct scatterlist *sgl, *sg;
-		unsigned char *p, *to;
-		unsigned int sg_size;
-		int i;
-
-		/* copy back read RDMA to unaligned sg */
-		mem	= mem_copy->copy_buf;
-
-		sgl	= (struct scatterlist *)iser_task->data[ISER_DIR_IN].buf;
-		sg_size = iser_task->data[ISER_DIR_IN].size;
-
-		p = mem;
-		for_each_sg(sgl, sg, sg_size, i) {
-			to = kmap_atomic(sg_page(sg));
-			memcpy(to + sg->offset,
-			       p,
-			       sg->length);
-			kunmap_atomic(to);
-			p += sg->length;
-		}
-	}
-
-	cmd_data_len = iser_task->data[cmd_dir].data_len;
 
-	if (cmd_data_len > ISER_KMALLOC_THRESHOLD)
-		free_pages((unsigned long)mem_copy->copy_buf,
-			   ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT);
-	else
-		kfree(mem_copy->copy_buf);
-
-	mem_copy->copy_buf = NULL;
-}
+	iser_task->dir[iser_dir] = 1;
+	dev = iser_task->iser_conn->ib_conn.device->ib_device;
 
-#define IS_4K_ALIGNED(addr)	((((unsigned long)addr) & ~MASK_4K) == 0)
+	data->dma_nents = ib_dma_map_sg(dev, data->sg, data->size, dma_dir);
+	if (unlikely(data->dma_nents == 0)) {
+		iser_err("dma_map_sg failed!!!\n");
+		return -EINVAL;
+	}
 
-/**
- * iser_sg_to_page_vec - Translates scatterlist entries to physical addresses
- * and returns the length of resulting physical address array (may be less than
- * the original due to possible compaction).
- *
- * we build a "page vec" under the assumption that the SG meets the RDMA
- * alignment requirements. Other then the first and last SG elements, all
- * the "internal" elements can be compacted into a list whose elements are
- * dma addresses of physical pages. The code supports also the weird case
- * where --few fragments of the same page-- are present in the SG as
- * consecutive elements. Also, it handles one entry SG.
- */
+	if (scsi_prot_sg_count(iser_task->sc)) {
+		struct iser_data_buf *pdata = &iser_task->prot[iser_dir];
 
-static int iser_sg_to_page_vec(struct iser_data_buf *data,
-			       struct iser_page_vec *page_vec,
-			       struct ib_device *ibdev)
-{
-	struct scatterlist *sg, *sgl = (struct scatterlist *)data->buf;
-	u64 start_addr, end_addr, page, chunk_start = 0;
-	unsigned long total_sz = 0;
-	unsigned int dma_len;
-	int i, new_chunk, cur_page, last_ent = data->dma_nents - 1;
-
-	/* compute the offset of first element */
-	page_vec->offset = (u64) sgl[0].offset & ~MASK_4K;
-
-	new_chunk = 1;
-	cur_page  = 0;
-	for_each_sg(sgl, sg, data->dma_nents, i) {
-		start_addr = ib_sg_dma_address(ibdev, sg);
-		if (new_chunk)
-			chunk_start = start_addr;
-		dma_len = ib_sg_dma_len(ibdev, sg);
-		end_addr = start_addr + dma_len;
-		total_sz += dma_len;
-
-		/* collect page fragments until aligned or end of SG list */
-		if (!IS_4K_ALIGNED(end_addr) && i < last_ent) {
-			new_chunk = 0;
-			continue;
+		pdata->dma_nents = ib_dma_map_sg(dev, pdata->sg, pdata->size, dma_dir);
+		if (unlikely(pdata->dma_nents == 0)) {
+			iser_err("protection dma_map_sg failed!!!\n");
+			goto out_unmap;
 		}
-		new_chunk = 1;
-
-		/* address of the first page in the contiguous chunk;
-		   masking relevant for the very first SG entry,
-		   which might be unaligned */
-		page = chunk_start & MASK_4K;
-		do {
-			page_vec->pages[cur_page++] = page;
-			page += SIZE_4K;
-		} while (page < end_addr);
 	}
 
-	page_vec->data_size = total_sz;
-	iser_dbg("page_vec->data_size:%d cur_page %d\n", page_vec->data_size,cur_page);
-	return cur_page;
+	return 0;
+
+out_unmap:
+	ib_dma_unmap_sg(dev, data->sg, data->size, dma_dir);
+	return -EINVAL;
 }
 
 
-/**
- * iser_data_buf_aligned_len - Tries to determine the maximal correctly aligned
- * for RDMA sub-list of a scatter-gather list of memory buffers, and  returns
- * the number of entries which are aligned correctly. Supports the case where
- * consecutive SG elements are actually fragments of the same physcial page.
- */
-static int iser_data_buf_aligned_len(struct iser_data_buf *data,
-				      struct ib_device *ibdev)
+void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
+			      enum iser_data_dir iser_dir,
+			      enum dma_data_direction dma_dir)
 {
-	struct scatterlist *sgl, *sg, *next_sg = NULL;
-	u64 start_addr, end_addr;
-	int i, ret_len, start_check = 0;
-
-	if (data->dma_nents == 1)
-		return 1;
-
-	sgl = (struct scatterlist *)data->buf;
-	start_addr  = ib_sg_dma_address(ibdev, sgl);
-
-	for_each_sg(sgl, sg, data->dma_nents, i) {
-		if (start_check && !IS_4K_ALIGNED(start_addr))
-			break;
-
-		next_sg = sg_next(sg);
-		if (!next_sg)
-			break;
+	struct iser_data_buf *data = &iser_task->data[iser_dir];
+	struct ib_device *dev;
 
-		end_addr    = start_addr + ib_sg_dma_len(ibdev, sg);
-		start_addr  = ib_sg_dma_address(ibdev, next_sg);
+	dev = iser_task->iser_conn->ib_conn.device->ib_device;
+	ib_dma_unmap_sg(dev, data->sg, data->size, dma_dir);
 
-		if (end_addr == start_addr) {
-			start_check = 0;
-			continue;
-		} else
-			start_check = 1;
+	if (scsi_prot_sg_count(iser_task->sc)) {
+		struct iser_data_buf *pdata = &iser_task->prot[iser_dir];
 
-		if (!IS_4K_ALIGNED(end_addr))
-			break;
+		ib_dma_unmap_sg(dev, pdata->sg, pdata->size, dma_dir);
 	}
-	ret_len = (next_sg) ? i : i+1;
-	iser_dbg("Found %d aligned entries out of %d in sg:0x%p\n",
-		 ret_len, data->dma_nents, data);
-	return ret_len;
 }
 
-static void iser_data_buf_dump(struct iser_data_buf *data,
-			       struct ib_device *ibdev)
+static int iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,
+			struct iser_mem_reg *reg)
 {
-	struct scatterlist *sgl = (struct scatterlist *)data->buf;
-	struct scatterlist *sg;
-	int i;
+	struct scatterlist *sg = mem->sg;
 
-	if (iser_debug_level == 0)
-		return;
+	reg->sge.lkey = device->pd->local_dma_lkey;
+	/*
+	 * FIXME: rework the registration code path to differentiate
+	 * rkey/lkey use cases
+	 */
 
-	for_each_sg(sgl, sg, data->dma_nents, i)
-		iser_warn("sg[%d] dma_addr:0x%lX page:0x%p "
-			 "off:0x%x sz:0x%x dma_len:0x%x\n",
-			 i, (unsigned long)ib_sg_dma_address(ibdev, sg),
-			 sg_page(sg), sg->offset,
-			 sg->length, ib_sg_dma_len(ibdev, sg));
-}
+	if (device->pd->flags & IB_PD_UNSAFE_GLOBAL_RKEY)
+		reg->rkey = device->pd->unsafe_global_rkey;
+	else
+		reg->rkey = 0;
+	reg->sge.addr = sg_dma_address(&sg[0]);
+	reg->sge.length = sg_dma_len(&sg[0]);
 
-static void iser_dump_page_vec(struct iser_page_vec *page_vec)
-{
-	int i;
+	iser_dbg("Single DMA entry: lkey=0x%x, rkey=0x%x, addr=0x%llx,"
+		 " length=0x%x\n", reg->sge.lkey, reg->rkey,
+		 reg->sge.addr, reg->sge.length);
 
-	iser_err("page vec length %d data size %d\n",
-		 page_vec->length, page_vec->data_size);
-	for (i = 0; i < page_vec->length; i++)
-		iser_err("%d %lx\n",i,(unsigned long)page_vec->pages[i]);
+	return 0;
 }
 
-static void iser_page_vec_build(struct iser_data_buf *data,
-				struct iser_page_vec *page_vec,
-				struct ib_device *ibdev)
+void iser_unreg_mem_fastreg(struct iscsi_iser_task *iser_task,
+			    enum iser_data_dir cmd_dir)
 {
-	int page_vec_len = 0;
-
-	page_vec->length = 0;
-	page_vec->offset = 0;
+	struct iser_mem_reg *reg = &iser_task->rdma_reg[cmd_dir];
+	struct iser_fr_desc *desc;
+	struct ib_mr_status mr_status;
 
-	iser_dbg("Translating sg sz: %d\n", data->dma_nents);
-	page_vec_len = iser_sg_to_page_vec(data, page_vec, ibdev);
-	iser_dbg("sg len %d page_vec_len %d\n", data->dma_nents,page_vec_len);
-
-	page_vec->length = page_vec_len;
+	desc = reg->desc;
+	if (!desc)
+		return;
 
-	if (page_vec_len * SIZE_4K < page_vec->data_size) {
-		iser_err("page_vec too short to hold this SG\n");
-		iser_data_buf_dump(data, ibdev);
-		iser_dump_page_vec(page_vec);
-		BUG();
+	/*
+	 * The signature MR cannot be invalidated and reused without checking.
+	 * libiscsi calls the check_protection transport handler only if
+	 * SCSI-Response is received. And the signature MR is not checked if
+	 * the task is completed for some other reason like a timeout or error
+	 * handling. That's why we must check the signature MR here before
+	 * putting it to the free pool.
+	 */
+	if (unlikely(desc->sig_protected)) {
+		desc->sig_protected = false;
+		ib_check_mr_status(desc->rsc.sig_mr, IB_MR_CHECK_SIG_STATUS,
+				   &mr_status);
 	}
+	iser_reg_desc_put_fr(&iser_task->iser_conn->ib_conn, reg->desc);
+	reg->desc = NULL;
 }
 
-int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
-			    struct iser_data_buf *data,
-			    enum iser_data_dir iser_dir,
-			    enum dma_data_direction dma_dir)
+static void iser_set_dif_domain(struct scsi_cmnd *sc,
+				struct ib_sig_domain *domain)
 {
-	struct ib_device *dev;
-
-	iser_task->dir[iser_dir] = 1;
-	dev = iser_task->iser_conn->ib_conn->device->ib_device;
+	domain->sig_type = IB_SIG_TYPE_T10_DIF;
+	domain->sig.dif.pi_interval = scsi_prot_interval(sc);
+	domain->sig.dif.ref_tag = t10_pi_ref_tag(scsi_cmd_to_rq(sc));
+	/*
+	 * At the moment we hard code those, but in the future
+	 * we will take them from sc.
+	 */
+	domain->sig.dif.apptag_check_mask = 0xffff;
+	domain->sig.dif.app_escape = true;
+	domain->sig.dif.ref_escape = true;
+	if (sc->prot_flags & SCSI_PROT_REF_INCREMENT)
+		domain->sig.dif.ref_remap = true;
+}
 
-	data->dma_nents = ib_dma_map_sg(dev, data->buf, data->size, dma_dir);
-	if (data->dma_nents == 0) {
-		iser_err("dma_map_sg failed!!!\n");
+static int iser_set_sig_attrs(struct scsi_cmnd *sc,
+			      struct ib_sig_attrs *sig_attrs)
+{
+	switch (scsi_get_prot_op(sc)) {
+	case SCSI_PROT_WRITE_INSERT:
+	case SCSI_PROT_READ_STRIP:
+		sig_attrs->mem.sig_type = IB_SIG_TYPE_NONE;
+		iser_set_dif_domain(sc, &sig_attrs->wire);
+		sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
+		break;
+	case SCSI_PROT_READ_INSERT:
+	case SCSI_PROT_WRITE_STRIP:
+		sig_attrs->wire.sig_type = IB_SIG_TYPE_NONE;
+		iser_set_dif_domain(sc, &sig_attrs->mem);
+		sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
+						IB_T10DIF_CSUM : IB_T10DIF_CRC;
+		break;
+	case SCSI_PROT_READ_PASS:
+	case SCSI_PROT_WRITE_PASS:
+		iser_set_dif_domain(sc, &sig_attrs->wire);
+		sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
+		iser_set_dif_domain(sc, &sig_attrs->mem);
+		sig_attrs->mem.sig.dif.bg_type = sc->prot_flags & SCSI_PROT_IP_CHECKSUM ?
+						IB_T10DIF_CSUM : IB_T10DIF_CRC;
+		break;
+	default:
+		iser_err("Unsupported PI operation %d\n",
+			 scsi_get_prot_op(sc));
 		return -EINVAL;
 	}
+
 	return 0;
 }
 
-void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task)
+static inline void iser_set_prot_checks(struct scsi_cmnd *sc, u8 *mask)
 {
-	struct ib_device *dev;
-	struct iser_data_buf *data;
+	*mask = 0;
+	if (sc->prot_flags & SCSI_PROT_REF_CHECK)
+		*mask |= IB_SIG_CHECK_REFTAG;
+	if (sc->prot_flags & SCSI_PROT_GUARD_CHECK)
+		*mask |= IB_SIG_CHECK_GUARD;
+}
 
-	dev = iser_task->iser_conn->ib_conn->device->ib_device;
+static inline void iser_inv_rkey(struct ib_send_wr *inv_wr, struct ib_mr *mr,
+				 struct ib_cqe *cqe, struct ib_send_wr *next_wr)
+{
+	inv_wr->opcode = IB_WR_LOCAL_INV;
+	inv_wr->wr_cqe = cqe;
+	inv_wr->ex.invalidate_rkey = mr->rkey;
+	inv_wr->send_flags = 0;
+	inv_wr->num_sge = 0;
+	inv_wr->next = next_wr;
+}
 
-	if (iser_task->dir[ISER_DIR_IN]) {
-		data = &iser_task->data[ISER_DIR_IN];
-		ib_dma_unmap_sg(dev, data->buf, data->size, DMA_FROM_DEVICE);
+static int iser_reg_sig_mr(struct iscsi_iser_task *iser_task,
+			   struct iser_data_buf *mem,
+			   struct iser_data_buf *sig_mem,
+			   struct iser_reg_resources *rsc,
+			   struct iser_mem_reg *sig_reg)
+{
+	struct iser_tx_desc *tx_desc = &iser_task->desc;
+	struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
+	struct ib_mr *mr = rsc->sig_mr;
+	struct ib_sig_attrs *sig_attrs = mr->sig_attrs;
+	struct ib_reg_wr *wr = &tx_desc->reg_wr;
+	int ret;
+
+	memset(sig_attrs, 0, sizeof(*sig_attrs));
+	ret = iser_set_sig_attrs(iser_task->sc, sig_attrs);
+	if (ret)
+		goto err;
+
+	iser_set_prot_checks(iser_task->sc, &sig_attrs->check_mask);
+
+	if (rsc->sig_mr->need_inval)
+		iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
+
+	ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
+
+	ret = ib_map_mr_sg_pi(mr, mem->sg, mem->dma_nents, NULL,
+			      sig_mem->sg, sig_mem->dma_nents, NULL, SZ_4K);
+	if (unlikely(ret)) {
+		iser_err("failed to map PI sg (%d)\n",
+			 mem->dma_nents + sig_mem->dma_nents);
+		goto err;
 	}
 
-	if (iser_task->dir[ISER_DIR_OUT]) {
-		data = &iser_task->data[ISER_DIR_OUT];
-		ib_dma_unmap_sg(dev, data->buf, data->size, DMA_TO_DEVICE);
+	memset(wr, 0, sizeof(*wr));
+	wr->wr.next = &tx_desc->send_wr;
+	wr->wr.opcode = IB_WR_REG_MR_INTEGRITY;
+	wr->wr.wr_cqe = cqe;
+	wr->wr.num_sge = 0;
+	wr->wr.send_flags = 0;
+	wr->mr = mr;
+	wr->key = mr->rkey;
+	wr->access = IB_ACCESS_LOCAL_WRITE |
+		     IB_ACCESS_REMOTE_READ |
+		     IB_ACCESS_REMOTE_WRITE;
+	rsc->sig_mr->need_inval = true;
+
+	sig_reg->sge.lkey = mr->lkey;
+	sig_reg->rkey = mr->rkey;
+	sig_reg->sge.addr = mr->iova;
+	sig_reg->sge.length = mr->length;
+
+	iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=%u\n",
+		 sig_reg->sge.lkey, sig_reg->rkey, sig_reg->sge.addr,
+		 sig_reg->sge.length);
+err:
+	return ret;
+}
+
+static int iser_fast_reg_mr(struct iscsi_iser_task *iser_task,
+			    struct iser_data_buf *mem,
+			    struct iser_reg_resources *rsc,
+			    struct iser_mem_reg *reg)
+{
+	struct iser_tx_desc *tx_desc = &iser_task->desc;
+	struct ib_cqe *cqe = &iser_task->iser_conn->ib_conn.reg_cqe;
+	struct ib_mr *mr = rsc->mr;
+	struct ib_reg_wr *wr = &tx_desc->reg_wr;
+	int n;
+
+	if (rsc->mr->need_inval)
+		iser_inv_rkey(&tx_desc->inv_wr, mr, cqe, &wr->wr);
+
+	ib_update_fast_reg_key(mr, ib_inc_rkey(mr->rkey));
+
+	n = ib_map_mr_sg(mr, mem->sg, mem->dma_nents, NULL, SZ_4K);
+	if (unlikely(n != mem->dma_nents)) {
+		iser_err("failed to map sg (%d/%d)\n",
+			 n, mem->dma_nents);
+		return n < 0 ? n : -EINVAL;
 	}
+
+	wr->wr.next = &tx_desc->send_wr;
+	wr->wr.opcode = IB_WR_REG_MR;
+	wr->wr.wr_cqe = cqe;
+	wr->wr.send_flags = 0;
+	wr->wr.num_sge = 0;
+	wr->mr = mr;
+	wr->key = mr->rkey;
+	wr->access = IB_ACCESS_LOCAL_WRITE  |
+		     IB_ACCESS_REMOTE_WRITE |
+		     IB_ACCESS_REMOTE_READ;
+
+	rsc->mr->need_inval = true;
+
+	reg->sge.lkey = mr->lkey;
+	reg->rkey = mr->rkey;
+	reg->sge.addr = mr->iova;
+	reg->sge.length = mr->length;
+
+	iser_dbg("lkey=0x%x rkey=0x%x addr=0x%llx length=0x%x\n",
+		 reg->sge.lkey, reg->rkey, reg->sge.addr, reg->sge.length);
+
+	return 0;
 }
 
-/**
- * iser_reg_rdma_mem - Registers memory intended for RDMA,
- * obtaining rkey and va
- *
- * returns 0 on success, errno code on failure
- */
-int iser_reg_rdma_mem(struct iscsi_iser_task *iser_task,
-		      enum   iser_data_dir        cmd_dir)
+int iser_reg_mem_fastreg(struct iscsi_iser_task *task,
+			 enum iser_data_dir dir,
+			 bool all_imm)
 {
-	struct iscsi_conn    *iscsi_conn = iser_task->iser_conn->iscsi_conn;
-	struct iser_conn     *ib_conn = iser_task->iser_conn->ib_conn;
-	struct iser_device   *device = ib_conn->device;
-	struct ib_device     *ibdev = device->ib_device;
-	struct iser_data_buf *mem = &iser_task->data[cmd_dir];
-	struct iser_regd_buf *regd_buf;
-	int aligned_len;
+	struct ib_conn *ib_conn = &task->iser_conn->ib_conn;
+	struct iser_device *device = ib_conn->device;
+	struct iser_data_buf *mem = &task->data[dir];
+	struct iser_mem_reg *reg = &task->rdma_reg[dir];
+	struct iser_fr_desc *desc;
+	bool use_dma_key;
 	int err;
-	int i;
-	struct scatterlist *sg;
-
-	regd_buf = &iser_task->rdma_regd[cmd_dir];
-
-	aligned_len = iser_data_buf_aligned_len(mem, ibdev);
-	if (aligned_len != mem->dma_nents ||
-	    (!ib_conn->fmr_pool && mem->dma_nents > 1)) {
-		iscsi_conn->fmr_unalign_cnt++;
-		iser_warn("rdma alignment violation (%d/%d aligned) or FMR not supported\n",
-			  aligned_len, mem->size);
-		iser_data_buf_dump(mem, ibdev);
-
-		/* unmap the command data before accessing it */
-		iser_dma_unmap_task_data(iser_task);
-
-		/* allocate copy buf, if we are writing, copy the */
-		/* unaligned scatterlist, dma map the copy        */
-		if (iser_start_rdma_unaligned_sg(iser_task, cmd_dir) != 0)
-				return -ENOMEM;
-		mem = &iser_task->data_copy[cmd_dir];
-	}
 
-	/* if there a single dma entry, FMR is not needed */
-	if (mem->dma_nents == 1) {
-		sg = (struct scatterlist *)mem->buf;
-
-		regd_buf->reg.lkey = device->mr->lkey;
-		regd_buf->reg.rkey = device->mr->rkey;
-		regd_buf->reg.len  = ib_sg_dma_len(ibdev, &sg[0]);
-		regd_buf->reg.va   = ib_sg_dma_address(ibdev, &sg[0]);
-		regd_buf->reg.is_fmr = 0;
-
-		iser_dbg("PHYSICAL Mem.register: lkey: 0x%08X rkey: 0x%08X  "
-			 "va: 0x%08lX sz: %ld]\n",
-			 (unsigned int)regd_buf->reg.lkey,
-			 (unsigned int)regd_buf->reg.rkey,
-			 (unsigned long)regd_buf->reg.va,
-			 (unsigned long)regd_buf->reg.len);
-	} else { /* use FMR for multiple dma entries */
-		iser_page_vec_build(mem, ib_conn->page_vec, ibdev);
-		err = iser_reg_page_vec(ib_conn, ib_conn->page_vec, &regd_buf->reg);
-		if (err && err != -EAGAIN) {
-			iser_data_buf_dump(mem, ibdev);
-			iser_err("mem->dma_nents = %d (dlength = 0x%x)\n",
-				 mem->dma_nents,
-				 ntoh24(iser_task->desc.iscsi_header.dlength));
-			iser_err("page_vec: data_size = 0x%x, length = %d, offset = 0x%x\n",
-				 ib_conn->page_vec->data_size, ib_conn->page_vec->length,
-				 ib_conn->page_vec->offset);
-			for (i=0 ; i<ib_conn->page_vec->length ; i++)
-				iser_err("page_vec[%d] = 0x%llx\n", i,
-					 (unsigned long long) ib_conn->page_vec->pages[i]);
-		}
-		if (err)
-			return err;
+	use_dma_key = mem->dma_nents == 1 && (all_imm || !iser_always_reg) &&
+		      scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL;
+	if (use_dma_key)
+		return iser_reg_dma(device, mem, reg);
+
+	desc = iser_reg_desc_get_fr(ib_conn);
+	if (scsi_get_prot_op(task->sc) == SCSI_PROT_NORMAL) {
+		err = iser_fast_reg_mr(task, mem, &desc->rsc, reg);
+		if (unlikely(err))
+			goto err_reg;
+	} else {
+		err = iser_reg_sig_mr(task, mem, &task->prot[dir],
+				      &desc->rsc, reg);
+		if (unlikely(err))
+			goto err_reg;
+
+		desc->sig_protected = true;
 	}
+
+	reg->desc = desc;
+
 	return 0;
+
+err_reg:
+	iser_reg_desc_put_fr(ib_conn, desc);
+
+	return err;
 }