diff mbox

[26/37] IB/rdmavt: Move memory registration into rdmavt

Message ID 20151207204451.8144.52356.stgit@phlsvslse11.ph.intel.com (mailing list archive)
State Superseded
Headers show

Commit Message

Dennis Dalessandro Dec. 7, 2015, 8:44 p.m. UTC
Use the memory registration routines in hfi1 and move them to rdmavt.
A follow on patch will address removing the duplicated code in the
hfi1 and qib drivers.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
---
 drivers/infiniband/sw/rdmavt/mr.c |  710 ++++++++++++++++++++++++++++++++++++-
 drivers/infiniband/sw/rdmavt/mr.h |   23 +
 drivers/infiniband/sw/rdmavt/vt.c |   23 +
 include/rdma/rdma_vt.h            |   19 +
 4 files changed, 759 insertions(+), 16 deletions(-)


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Comments

Sagi Grimberg Dec. 10, 2015, 2:24 p.m. UTC | #1
>   /**
> @@ -83,7 +357,31 @@ struct ib_mr *rvt_reg_phys_mr(struct ib_pd *pd,
>   			      int num_phys_buf, int acc, u64 *iova_start)
>   {

Why do we even bother with reg_phys_mr? Let's drop it entirely.
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Dennis Dalessandro Dec. 10, 2015, 3:14 p.m. UTC | #2
On Thu, Dec 10, 2015 at 04:24:44PM +0200, Sagi Grimberg wrote:
>
>
>>   /**
>>@@ -83,7 +357,31 @@ struct ib_mr *rvt_reg_phys_mr(struct ib_pd *pd,
>>   			      int num_phys_buf, int acc, u64 *iova_start)
>>   {
>
>Why do we even bother with reg_phys_mr? Let's drop it entirely.

Why? Because, it exists in qib and hfi1.

However, it seems no one is actually using this in the kernel these days and 
the core support was removed in commit 1241d7bf. Yet the function pointer 
still exists in struct ib_device. Are there plans to remove this?

For this patch series I'll go ahead and remove rvt_reg_phys_mr.

-Denny
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Christoph Hellwig Dec. 10, 2015, 3:25 p.m. UTC | #3
On Thu, Dec 10, 2015 at 10:14:56AM -0500, Dennis Dalessandro wrote:
> Why? Because, it exists in qib and hfi1.
> 
> However, it seems no one is actually using this in the kernel these days and
> the core support was removed in commit 1241d7bf. Yet the function pointer
> still exists in struct ib_device. Are there plans to remove this?

Yes, I've send a patch that remove it, and which only got positive
review so far.
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diff mbox

Patch

diff --git a/drivers/infiniband/sw/rdmavt/mr.c b/drivers/infiniband/sw/rdmavt/mr.c
index a4f4581..e809aaa 100644
--- a/drivers/infiniband/sw/rdmavt/mr.c
+++ b/drivers/infiniband/sw/rdmavt/mr.c
@@ -49,8 +49,252 @@ 
  */
 
 #include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <rdma/ib_umem.h>
+#include <rdma/rdma_vt.h>
+#include "vt.h"
 #include "mr.h"
 
+/*
+ * Do any intilization needed when a driver registers with rdmavt.
+ */
+int rvt_driver_mr_init(struct rvt_dev_info *rdi)
+{
+	unsigned int lkey_table_size = rdi->dparms.lkey_table_size;
+	unsigned lk_tab_size;
+	int i;
+
+	if (rdi->flags & RVT_FLAG_MR_INIT_DRIVER) {
+		rvt_pr_info(rdi, "Driver is doing MR init.\n");
+		return 0;
+	}
+
+	/*
+	 * The top hfi1_lkey_table_size bits are used to index the
+	 * table.  The lower 8 bits can be owned by the user (copied from
+	 * the LKEY).  The remaining bits act as a generation number or tag.
+	 */
+	if (!lkey_table_size)
+		return -EINVAL;
+
+	spin_lock_init(&rdi->lk_table.lock);
+
+	rdi->lk_table.max = 1 << lkey_table_size;
+
+	/* ensure generation is at least 4 bits */
+	if (lkey_table_size > RVT_MAX_LKEY_TABLE_BITS) {
+		rvt_pr_warn(rdi, "lkey bits %u too large, reduced to %u\n",
+			    lkey_table_size, RVT_MAX_LKEY_TABLE_BITS);
+		rdi->dparms.lkey_table_size = RVT_MAX_LKEY_TABLE_BITS;
+		lkey_table_size = rdi->dparms.lkey_table_size;
+	}
+	lk_tab_size = rdi->lk_table.max * sizeof(*rdi->lk_table.table);
+	rdi->lk_table.table = (struct rvt_mregion __rcu **)
+			       vmalloc(lk_tab_size);
+	if (!rdi->lk_table.table)
+		return -ENOMEM;
+
+	RCU_INIT_POINTER(rdi->dma_mr, NULL);
+	for (i = 0; i < rdi->lk_table.max; i++)
+		RCU_INIT_POINTER(rdi->lk_table.table[i], NULL);
+
+	return 0;
+}
+
+/*
+ * called when drivers have unregistered or perhaps failed to register with us
+ */
+void rvt_mr_exit(struct rvt_dev_info *rdi)
+{
+	if (rdi->dma_mr)
+		rvt_pr_err(rdi, "DMA MR not null!\n");
+
+	vfree(rdi->lk_table.table);
+}
+
+static void rvt_deinit_mregion(struct rvt_mregion *mr)
+{
+	int i = mr->mapsz;
+
+	mr->mapsz = 0;
+	while (i)
+		kfree(mr->map[--i]);
+}
+
+static int rvt_init_mregion(struct rvt_mregion *mr, struct ib_pd *pd,
+			    int count)
+{
+	int m, i = 0;
+
+	mr->mapsz = 0;
+	m = (count + RVT_SEGSZ - 1) / RVT_SEGSZ;
+	for (; i < m; i++) {
+		mr->map[i] = kzalloc(sizeof(*mr->map[0]), GFP_KERNEL);
+		if (!mr->map[i]) {
+			rvt_deinit_mregion(mr);
+			return -ENOMEM;
+		}
+		mr->mapsz++;
+	}
+	init_completion(&mr->comp);
+	/* count returning the ptr to user */
+	atomic_set(&mr->refcount, 1);
+	mr->pd = pd;
+	mr->max_segs = count;
+	return 0;
+}
+
+/**
+ * rvt_alloc_lkey - allocate an lkey
+ * @mr: memory region that this lkey protects
+ * @dma_region: 0->normal key, 1->restricted DMA key
+ *
+ * Returns 0 if successful, otherwise returns -errno.
+ *
+ * Increments mr reference count as required.
+ *
+ * Sets the lkey field mr for non-dma regions.
+ *
+ */
+static int rvt_alloc_lkey(struct rvt_mregion *mr, int dma_region)
+{
+	unsigned long flags;
+	u32 r;
+	u32 n;
+	int ret = 0;
+	struct rvt_dev_info *dev = ib_to_rvt(mr->pd->device);
+	struct rvt_lkey_table *rkt = &dev->lk_table;
+
+	rvt_get_mr(mr);
+	spin_lock_irqsave(&rkt->lock, flags);
+
+	/* special case for dma_mr lkey == 0 */
+	if (dma_region) {
+		struct rvt_mregion *tmr;
+
+		tmr = rcu_access_pointer(dev->dma_mr);
+		if (!tmr) {
+			rcu_assign_pointer(dev->dma_mr, mr);
+			mr->lkey_published = 1;
+		} else {
+			rvt_put_mr(mr);
+		}
+		goto success;
+	}
+
+	/* Find the next available LKEY */
+	r = rkt->next;
+	n = r;
+	for (;;) {
+		if (!rcu_access_pointer(rkt->table[r]))
+			break;
+		r = (r + 1) & (rkt->max - 1);
+		if (r == n)
+			goto bail;
+	}
+	rkt->next = (r + 1) & (rkt->max - 1);
+	/*
+	 * Make sure lkey is never zero which is reserved to indicate an
+	 * unrestricted LKEY.
+	 */
+	rkt->gen++;
+	/*
+	 * bits are capped to ensure enough bits for generation number
+	 */
+	mr->lkey = (r << (32 - dev->dparms.lkey_table_size)) |
+		((((1 << (24 - dev->dparms.lkey_table_size)) - 1) & rkt->gen)
+		 << 8);
+	if (mr->lkey == 0) {
+		mr->lkey |= 1 << 8;
+		rkt->gen++;
+	}
+	rcu_assign_pointer(rkt->table[r], mr);
+	mr->lkey_published = 1;
+success:
+	spin_unlock_irqrestore(&rkt->lock, flags);
+out:
+	return ret;
+bail:
+	rvt_put_mr(mr);
+	spin_unlock_irqrestore(&rkt->lock, flags);
+	ret = -ENOMEM;
+	goto out;
+}
+
+/**
+ * rvt_free_lkey - free an lkey
+ * @mr: mr to free from tables
+ */
+static void rvt_free_lkey(struct rvt_mregion *mr)
+{
+	unsigned long flags;
+	u32 lkey = mr->lkey;
+	u32 r;
+	struct rvt_dev_info *dev = ib_to_rvt(mr->pd->device);
+	struct rvt_lkey_table *rkt = &dev->lk_table;
+	int freed = 0;
+
+	spin_lock_irqsave(&rkt->lock, flags);
+	if (!mr->lkey_published)
+		goto out;
+	if (lkey == 0) {
+		RCU_INIT_POINTER(dev->dma_mr, NULL);
+	} else {
+		r = lkey >> (32 - dev->dparms.lkey_table_size);
+		RCU_INIT_POINTER(rkt->table[r], NULL);
+	}
+	mr->lkey_published = 0;
+	freed++;
+out:
+	spin_unlock_irqrestore(&rkt->lock, flags);
+	if (freed) {
+		synchronize_rcu();
+		rvt_put_mr(mr);
+	}
+}
+
+static struct rvt_mr *__rvt_alloc_mr(int count, struct ib_pd *pd)
+{
+	struct rvt_mr *mr;
+	int rval = -ENOMEM;
+	int m;
+
+	/* Allocate struct plus pointers to first level page tables. */
+	m = (count + RVT_SEGSZ - 1) / RVT_SEGSZ;
+	mr = kzalloc(sizeof(*mr) + m * sizeof(mr->mr.map[0]), GFP_KERNEL);
+	if (!mr)
+		goto bail;
+
+	rval = rvt_init_mregion(&mr->mr, pd, count);
+	if (rval)
+		goto bail;
+	/*
+	 * ib_reg_phys_mr() will initialize mr->ibmr except for
+	 * lkey and rkey.
+	 */
+	rval = rvt_alloc_lkey(&mr->mr, 0);
+	if (rval)
+		goto bail_mregion;
+	mr->ibmr.lkey = mr->mr.lkey;
+	mr->ibmr.rkey = mr->mr.lkey;
+done:
+	return mr;
+
+bail_mregion:
+	rvt_deinit_mregion(&mr->mr);
+bail:
+	kfree(mr);
+	mr = ERR_PTR(rval);
+	goto done;
+}
+
+static void __rvt_free_mr(struct rvt_mr *mr)
+{
+	rvt_deinit_mregion(&mr->mr);
+	rvt_free_lkey(&mr->mr);
+	vfree(mr);
+}
+
 /**
  * rvt_get_dma_mr - get a DMA memory region
  * @pd: protection domain for this memory region
@@ -62,11 +306,41 @@ 
  */
 struct ib_mr *rvt_get_dma_mr(struct ib_pd *pd, int acc)
 {
-	/*
-	 * Alloc mr and init it.
-	 * Alloc lkey.
-	 */
-	return ERR_PTR(-ENOMEM);
+	struct rvt_mr *mr;
+	struct ib_mr *ret;
+	int rval;
+
+	if (ibpd_to_rvtpd(pd)->user)
+		return ERR_PTR(-EPERM);
+
+	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
+	if (!mr) {
+		ret = ERR_PTR(-ENOMEM);
+		goto bail;
+	}
+
+	rval = rvt_init_mregion(&mr->mr, pd, 0);
+	if (rval) {
+		ret = ERR_PTR(rval);
+		goto bail;
+	}
+
+	rval = rvt_alloc_lkey(&mr->mr, 1);
+	if (rval) {
+		ret = ERR_PTR(rval);
+		goto bail_mregion;
+	}
+
+	mr->mr.access_flags = acc;
+	ret = &mr->ibmr;
+done:
+	return ret;
+
+bail_mregion:
+	rvt_deinit_mregion(&mr->mr);
+bail:
+	kfree(mr);
+	goto done;
 }
 
 /**
@@ -83,7 +357,31 @@  struct ib_mr *rvt_reg_phys_mr(struct ib_pd *pd,
 			      int num_phys_buf, int acc, u64 *iova_start)
 {
 	/* Alloc mr and build it up */
-	return ERR_PTR(-ENOMEM);
+	struct rvt_mr *mr;
+	int n, m, i;
+
+	mr = __rvt_alloc_mr(num_phys_buf, pd);
+	if (IS_ERR(mr))
+		return (struct ib_mr *)mr;
+
+	mr->mr.user_base = *iova_start;
+	mr->mr.iova = *iova_start;
+	mr->mr.access_flags = acc;
+
+	m = 0;
+	n = 0;
+	for (i = 0; i < num_phys_buf; i++) {
+		mr->mr.map[m]->segs[n].vaddr = (void *)buffer_list[i].addr;
+		mr->mr.map[m]->segs[n].length = buffer_list[i].size;
+		mr->mr.length += buffer_list[i].size;
+		n++;
+		if (n == RVT_SEGSZ) {
+			m++;
+			n = 0;
+		}
+	}
+
+	return &mr->ibmr;
 }
 
 /**
@@ -100,7 +398,64 @@  struct ib_mr *rvt_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 			      u64 virt_addr, int mr_access_flags,
 			      struct ib_udata *udata)
 {
-	return ERR_PTR(-ENOMEM);
+	struct rvt_mr *mr;
+	struct ib_umem *umem;
+	struct scatterlist *sg;
+	int n, m, entry;
+	struct ib_mr *ret;
+
+	if (length == 0)
+		return ERR_PTR(-EINVAL);
+
+	umem = ib_umem_get(pd->uobject->context, start, length,
+			   mr_access_flags, 0);
+	if (IS_ERR(umem))
+		return (void *)umem;
+
+	n = umem->nmap;
+
+	mr = __rvt_alloc_mr(n, pd);
+	if (IS_ERR(mr)) {
+		ret = (struct ib_mr *)mr;
+		goto bail_umem;
+	}
+
+	mr->mr.user_base = start;
+	mr->mr.iova = virt_addr;
+	mr->mr.length = length;
+	mr->mr.offset = ib_umem_offset(umem);
+	mr->mr.access_flags = mr_access_flags;
+	mr->umem = umem;
+
+	if (is_power_of_2(umem->page_size))
+		mr->mr.page_shift = ilog2(umem->page_size);
+	m = 0;
+	n = 0;
+	for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
+		void *vaddr;
+
+		vaddr = page_address(sg_page(sg));
+		if (!vaddr) {
+			ret = ERR_PTR(-EINVAL);
+			goto bail_inval;
+		}
+		mr->mr.map[m]->segs[n].vaddr = vaddr;
+		mr->mr.map[m]->segs[n].length = umem->page_size;
+		n++;
+		if (n == RVT_SEGSZ) {
+			m++;
+			n = 0;
+		}
+	}
+	return &mr->ibmr;
+
+bail_inval:
+	__rvt_free_mr(mr);
+
+bail_umem:
+	ib_umem_release(umem);
+
+	return ret;
 }
 
 /**
@@ -114,7 +469,29 @@  struct ib_mr *rvt_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
  */
 int rvt_dereg_mr(struct ib_mr *ibmr)
 {
-	return -EINVAL;
+	struct rvt_mr *mr = to_imr(ibmr);
+	struct rvt_dev_info *rdi = ib_to_rvt(ibmr->pd->device);
+	int ret = 0;
+	unsigned long timeout;
+
+	rvt_free_lkey(&mr->mr);
+
+	rvt_put_mr(&mr->mr); /* will set completion if last */
+	timeout = wait_for_completion_timeout(&mr->mr.comp, 5 * HZ);
+	if (!timeout) {
+		rvt_pr_err(rdi,
+			   "rvt_dereg_mr timeout mr %p pd %p refcount %u\n",
+			   mr, mr->mr.pd, atomic_read(&mr->mr.refcount));
+		rvt_get_mr(&mr->mr);
+		ret = -EBUSY;
+		goto out;
+	}
+	rvt_deinit_mregion(&mr->mr);
+	if (mr->umem)
+		ib_umem_release(mr->umem);
+	kfree(mr);
+out:
+	return ret;
 }
 
 /**
@@ -129,7 +506,16 @@  struct ib_mr *rvt_alloc_mr(struct ib_pd *pd,
 			   enum ib_mr_type mr_type,
 			   u32 max_num_sg)
 {
-	return ERR_PTR(-ENOMEM);
+	struct rvt_mr *mr;
+
+	if (mr_type != IB_MR_TYPE_MEM_REG)
+		return ERR_PTR(-EINVAL);
+
+	mr = __rvt_alloc_mr(max_num_sg, pd);
+	if (IS_ERR(mr))
+		return (struct ib_mr *)mr;
+
+	return &mr->ibmr;
 }
 
 /**
@@ -143,7 +529,49 @@  struct ib_mr *rvt_alloc_mr(struct ib_pd *pd,
 struct ib_fmr *rvt_alloc_fmr(struct ib_pd *pd, int mr_access_flags,
 			     struct ib_fmr_attr *fmr_attr)
 {
-	return ERR_PTR(-ENOMEM);
+	struct rvt_fmr *fmr;
+	int m;
+	struct ib_fmr *ret;
+	int rval = -ENOMEM;
+
+	/* Allocate struct plus pointers to first level page tables. */
+	m = (fmr_attr->max_pages + RVT_SEGSZ - 1) / RVT_SEGSZ;
+	fmr = kzalloc(sizeof(*fmr) + m * sizeof(fmr->mr.map[0]), GFP_KERNEL);
+	if (!fmr)
+		goto bail;
+
+	rval = rvt_init_mregion(&fmr->mr, pd, fmr_attr->max_pages);
+	if (rval)
+		goto bail;
+
+	/*
+	 * ib_alloc_fmr() will initialize fmr->ibfmr except for lkey &
+	 * rkey.
+	 */
+	rval = rvt_alloc_lkey(&fmr->mr, 0);
+	if (rval)
+		goto bail_mregion;
+	fmr->ibfmr.rkey = fmr->mr.lkey;
+	fmr->ibfmr.lkey = fmr->mr.lkey;
+	/*
+	 * Resources are allocated but no valid mapping (RKEY can't be
+	 * used).
+	 */
+	fmr->mr.access_flags = mr_access_flags;
+	fmr->mr.max_segs = fmr_attr->max_pages;
+	fmr->mr.page_shift = fmr_attr->page_shift;
+
+	ret = &fmr->ibfmr;
+done:
+	return ret;
+
+bail_mregion:
+	rvt_deinit_mregion(&fmr->mr);
+bail:
+	kfree(fmr);
+	ret = ERR_PTR(rval);
+	goto done;
+
 }
 
 /**
@@ -159,7 +587,38 @@  struct ib_fmr *rvt_alloc_fmr(struct ib_pd *pd, int mr_access_flags,
 int rvt_map_phys_fmr(struct ib_fmr *ibfmr, u64 *page_list,
 		     int list_len, u64 iova)
 {
-	return -EINVAL;
+	struct rvt_fmr *fmr = to_ifmr(ibfmr);
+	struct rvt_lkey_table *rkt;
+	unsigned long flags;
+	int m, n, i;
+	u32 ps;
+	struct rvt_dev_info *rdi = ib_to_rvt(ibfmr->device);
+
+	i = atomic_read(&fmr->mr.refcount);
+	if (i > 2)
+		return -EBUSY;
+
+	if (list_len > fmr->mr.max_segs)
+		return -EINVAL;
+
+	rkt = &rdi->lk_table;
+	spin_lock_irqsave(&rkt->lock, flags);
+	fmr->mr.user_base = iova;
+	fmr->mr.iova = iova;
+	ps = 1 << fmr->mr.page_shift;
+	fmr->mr.length = list_len * ps;
+	m = 0;
+	n = 0;
+	for (i = 0; i < list_len; i++) {
+		fmr->mr.map[m]->segs[n].vaddr = (void *)page_list[i];
+		fmr->mr.map[m]->segs[n].length = ps;
+		if (++n == RVT_SEGSZ) {
+			m++;
+			n = 0;
+		}
+	}
+	spin_unlock_irqrestore(&rkt->lock, flags);
+	return 0;
 }
 
 /**
@@ -170,7 +629,21 @@  int rvt_map_phys_fmr(struct ib_fmr *ibfmr, u64 *page_list,
  */
 int rvt_unmap_fmr(struct list_head *fmr_list)
 {
-	return -EINVAL;
+	struct rvt_fmr *fmr;
+	struct rvt_lkey_table *rkt;
+	unsigned long flags;
+	struct rvt_dev_info *rdi;
+
+	list_for_each_entry(fmr, fmr_list, ibfmr.list) {
+		rdi = ib_to_rvt(fmr->ibfmr.device);
+		rkt = &rdi->lk_table;
+		spin_lock_irqsave(&rkt->lock, flags);
+		fmr->mr.user_base = 0;
+		fmr->mr.iova = 0;
+		fmr->mr.length = 0;
+		spin_unlock_irqrestore(&rkt->lock, flags);
+	}
+	return 0;
 }
 
 /**
@@ -181,5 +654,216 @@  int rvt_unmap_fmr(struct list_head *fmr_list)
  */
 int rvt_dealloc_fmr(struct ib_fmr *ibfmr)
 {
-	return -EINVAL;
+	struct rvt_fmr *fmr = to_ifmr(ibfmr);
+	int ret = 0;
+	unsigned long timeout;
+
+	rvt_free_lkey(&fmr->mr);
+	rvt_put_mr(&fmr->mr); /* will set completion if last */
+	timeout = wait_for_completion_timeout(&fmr->mr.comp, 5 * HZ);
+	if (!timeout) {
+		rvt_get_mr(&fmr->mr);
+		ret = -EBUSY;
+		goto out;
+	}
+	rvt_deinit_mregion(&fmr->mr);
+	kfree(fmr);
+out:
+	return ret;
+}
+
+/**
+ * rvt_lkey_ok - check IB SGE for validity and initialize
+ * @rkt: table containing lkey to check SGE against
+ * @pd: protection domain
+ * @isge: outgoing internal SGE
+ * @sge: SGE to check
+ * @acc: access flags
+ *
+ * Return 1 if valid and successful, otherwise returns 0.
+ *
+ * increments the reference count upon success
+ *
+ * Check the IB SGE for validity and initialize our internal version
+ * of it.
+ */
+int rvt_lkey_ok(struct rvt_lkey_table *rkt, struct rvt_pd *pd,
+		struct rvt_sge *isge, struct ib_sge *sge, int acc)
+{
+	struct rvt_mregion *mr;
+	unsigned n, m;
+	size_t off;
+	struct rvt_dev_info *dev = ib_to_rvt(pd->ibpd.device);
+
+	/*
+	 * We use LKEY == zero for kernel virtual addresses
+	 * (see rvt_get_dma_mr and dma.c).
+	 */
+	rcu_read_lock();
+	if (sge->lkey == 0) {
+		if (pd->user)
+			goto bail;
+		mr = rcu_dereference(dev->dma_mr);
+		if (!mr)
+			goto bail;
+		atomic_inc(&mr->refcount);
+		rcu_read_unlock();
+
+		isge->mr = mr;
+		isge->vaddr = (void *)sge->addr;
+		isge->length = sge->length;
+		isge->sge_length = sge->length;
+		isge->m = 0;
+		isge->n = 0;
+		goto ok;
+	}
+	mr = rcu_dereference(
+		rkt->table[(sge->lkey >> (32 - dev->dparms.lkey_table_size))]);
+	if (unlikely(!mr || mr->lkey != sge->lkey || mr->pd != &pd->ibpd))
+		goto bail;
+
+	off = sge->addr - mr->user_base;
+	if (unlikely(sge->addr < mr->user_base ||
+		     off + sge->length > mr->length ||
+		     (mr->access_flags & acc) != acc))
+		goto bail;
+	atomic_inc(&mr->refcount);
+	rcu_read_unlock();
+
+	off += mr->offset;
+	if (mr->page_shift) {
+		/*
+		 * page sizes are uniform power of 2 so no loop is necessary
+		 * entries_spanned_by_off is the number of times the loop below
+		 * would have executed.
+		*/
+		size_t entries_spanned_by_off;
+
+		entries_spanned_by_off = off >> mr->page_shift;
+		off -= (entries_spanned_by_off << mr->page_shift);
+		m = entries_spanned_by_off / RVT_SEGSZ;
+		n = entries_spanned_by_off % RVT_SEGSZ;
+	} else {
+		m = 0;
+		n = 0;
+		while (off >= mr->map[m]->segs[n].length) {
+			off -= mr->map[m]->segs[n].length;
+			n++;
+			if (n >= RVT_SEGSZ) {
+				m++;
+				n = 0;
+			}
+		}
+	}
+	isge->mr = mr;
+	isge->vaddr = mr->map[m]->segs[n].vaddr + off;
+	isge->length = mr->map[m]->segs[n].length - off;
+	isge->sge_length = sge->length;
+	isge->m = m;
+	isge->n = n;
+ok:
+	return 1;
+bail:
+	rcu_read_unlock();
+	return 0;
+}
+EXPORT_SYMBOL(rvt_lkey_ok);
+
+/**
+ * rvt_rkey_ok - check the IB virtual address, length, and RKEY
+ * @qp: qp for validation
+ * @sge: SGE state
+ * @len: length of data
+ * @vaddr: virtual address to place data
+ * @rkey: rkey to check
+ * @acc: access flags
+ *
+ * Return 1 if successful, otherwise 0.
+ *
+ * increments the reference count upon success
+ */
+int rvt_rkey_ok(struct rvt_qp *qp, struct rvt_sge *sge,
+		u32 len, u64 vaddr, u32 rkey, int acc)
+{
+	struct rvt_dev_info *dev = ib_to_rvt(qp->ibqp.device);
+	struct rvt_lkey_table *rkt = &dev->lk_table;
+	struct rvt_mregion *mr;
+	unsigned n, m;
+	size_t off;
+
+	/*
+	 * We use RKEY == zero for kernel virtual addresses
+	 * (see rvt_get_dma_mr and dma.c).
+	 */
+	rcu_read_lock();
+	if (rkey == 0) {
+		struct rvt_pd *pd = ibpd_to_rvtpd(qp->ibqp.pd);
+		struct rvt_dev_info *rdi = ib_to_rvt(pd->ibpd.device);
+
+		if (pd->user)
+			goto bail;
+		mr = rcu_dereference(rdi->dma_mr);
+		if (!mr)
+			goto bail;
+		atomic_inc(&mr->refcount);
+		rcu_read_unlock();
+
+		sge->mr = mr;
+		sge->vaddr = (void *)vaddr;
+		sge->length = len;
+		sge->sge_length = len;
+		sge->m = 0;
+		sge->n = 0;
+		goto ok;
+	}
+
+	mr = rcu_dereference(
+		rkt->table[(rkey >> (32 - dev->dparms.lkey_table_size))]);
+	if (unlikely(!mr || mr->lkey != rkey || qp->ibqp.pd != mr->pd))
+		goto bail;
+
+	off = vaddr - mr->iova;
+	if (unlikely(vaddr < mr->iova || off + len > mr->length ||
+		     (mr->access_flags & acc) == 0))
+		goto bail;
+	atomic_inc(&mr->refcount);
+	rcu_read_unlock();
+
+	off += mr->offset;
+	if (mr->page_shift) {
+		/*
+		 * page sizes are uniform power of 2 so no loop is necessary
+		 * entries_spanned_by_off is the number of times the loop below
+		 * would have executed.
+		*/
+		size_t entries_spanned_by_off;
+
+		entries_spanned_by_off = off >> mr->page_shift;
+		off -= (entries_spanned_by_off << mr->page_shift);
+		m = entries_spanned_by_off / RVT_SEGSZ;
+		n = entries_spanned_by_off % RVT_SEGSZ;
+	} else {
+		m = 0;
+		n = 0;
+		while (off >= mr->map[m]->segs[n].length) {
+			off -= mr->map[m]->segs[n].length;
+			n++;
+			if (n >= RVT_SEGSZ) {
+				m++;
+				n = 0;
+			}
+		}
+	}
+	sge->mr = mr;
+	sge->vaddr = mr->map[m]->segs[n].vaddr + off;
+	sge->length = mr->map[m]->segs[n].length - off;
+	sge->sge_length = len;
+	sge->m = m;
+	sge->n = n;
+ok:
+	return 1;
+bail:
+	rcu_read_unlock();
+	return 0;
 }
+EXPORT_SYMBOL(rvt_rkey_ok);
diff --git a/drivers/infiniband/sw/rdmavt/mr.h b/drivers/infiniband/sw/rdmavt/mr.h
index 1d3d14b..3b43278 100644
--- a/drivers/infiniband/sw/rdmavt/mr.h
+++ b/drivers/infiniband/sw/rdmavt/mr.h
@@ -52,6 +52,29 @@ 
  */
 
 #include <rdma/rdma_vt.h>
+struct rvt_fmr {
+	struct ib_fmr ibfmr;
+	struct rvt_mregion mr;        /* must be last */
+};
+
+struct rvt_mr {
+	struct ib_mr ibmr;
+	struct ib_umem *umem;
+	struct rvt_mregion mr;  /* must be last */
+};
+
+static inline struct rvt_fmr *to_ifmr(struct ib_fmr *ibfmr)
+{
+	return container_of(ibfmr, struct rvt_fmr, ibfmr);
+}
+
+static inline struct rvt_mr *to_imr(struct ib_mr *ibmr)
+{
+	return container_of(ibmr, struct rvt_mr, ibmr);
+}
+
+int rvt_driver_mr_init(struct rvt_dev_info *rdi);
+void rvt_mr_exit(struct rvt_dev_info *rdi);
 
 /* Mem Regions */
 struct ib_mr *rvt_get_dma_mr(struct ib_pd *pd, int acc);
diff --git a/drivers/infiniband/sw/rdmavt/vt.c b/drivers/infiniband/sw/rdmavt/vt.c
index 6d7b435..8138ee4 100644
--- a/drivers/infiniband/sw/rdmavt/vt.c
+++ b/drivers/infiniband/sw/rdmavt/vt.c
@@ -220,6 +220,8 @@  static int rvt_get_port_immutable(struct ib_device *ibdev, u8 port_num,
 int rvt_register_device(struct rvt_dev_info *rdi)
 {
 	/* Validate that drivers have provided the right information */
+	int ret = 0;
+
 	if (!rdi)
 		return -EINVAL;
 
@@ -268,6 +270,11 @@  int rvt_register_device(struct rvt_dev_info *rdi)
 	CDR(rdi, detach_mcast);
 
 	/* Mem Region */
+	ret = rvt_driver_mr_init(rdi);
+	if (ret) {
+		rvt_pr_err(rdi, "Error in driver MR init.\n");
+		goto bail_no_mr;
+	}
 	CDR(rdi, get_dma_mr);
 	CDR(rdi, reg_phys_mr);
 	CDR(rdi, reg_user_mr);
@@ -296,10 +303,21 @@  int rvt_register_device(struct rvt_dev_info *rdi)
 	spin_lock_init(&rdi->n_pds_lock);
 	rdi->n_pds_allocated = 0;
 
+	/* We are now good to announce we exist */
+	ret =  ib_register_device(&rdi->ibdev, rdi->driver_f.port_callback);
+	if (ret) {
+		rvt_pr_err(rdi, "Failed to register driver with ib core.\n");
+		goto bail_mr;
+	}
+
 	rvt_pr_info(rdi, "Registration with rdmavt done.\n");
+	return ret;
 
-	/* We are now good to announce we exist */
-	return ib_register_device(&rdi->ibdev, rdi->driver_f.port_callback);
+bail_mr:
+	rvt_mr_exit(rdi);
+
+bail_no_mr:
+	return ret;
 }
 EXPORT_SYMBOL(rvt_register_device);
 
@@ -309,5 +327,6 @@  void rvt_unregister_device(struct rvt_dev_info *rdi)
 		return;
 
 	ib_unregister_device(&rdi->ibdev);
+	rvt_mr_exit(rdi);
 }
 EXPORT_SYMBOL(rvt_unregister_device);
diff --git a/include/rdma/rdma_vt.h b/include/rdma/rdma_vt.h
index aa76cc3..2d2987b 100644
--- a/include/rdma/rdma_vt.h
+++ b/include/rdma/rdma_vt.h
@@ -394,6 +394,7 @@  struct rvt_driver_params {
 	 * Anything driver specific that is not covered by props
 	 * For instance special module parameters. Goes here.
 	 */
+	unsigned int lkey_table_size;
 };
 
 /*
@@ -419,6 +420,8 @@  struct rvt_pd {
 };
 
 struct rvt_dev_info {
+	struct ib_device ibdev; /* Keep this first. Nothing above here */
+
 	/*
 	 * Prior to calling for registration the driver will be responsible for
 	 * allocating space for this structure. The driver will also need to
@@ -429,7 +432,6 @@  struct rvt_dev_info {
 	 * The driver will also be
 	 * responsible for filling in certain members of dparms.props
 	 */
-	struct ib_device ibdev;
 
 	/* Driver specific properties */
 	struct rvt_driver_params dparms;
@@ -459,7 +461,22 @@  static inline struct rvt_dev_info *ib_to_rvt(struct ib_device *ibdev)
 	return  container_of(ibdev, struct rvt_dev_info, ibdev);
 }
 
+static inline void rvt_put_mr(struct rvt_mregion *mr)
+{
+	if (unlikely(atomic_dec_and_test(&mr->refcount)))
+		complete(&mr->comp);
+}
+
+static inline void rvt_get_mr(struct rvt_mregion *mr)
+{
+	atomic_inc(&mr->refcount);
+}
+
 int rvt_register_device(struct rvt_dev_info *rvd);
 void rvt_unregister_device(struct rvt_dev_info *rvd);
+int rvt_rkey_ok(struct rvt_qp *qp, struct rvt_sge *sge,
+		u32 len, u64 vaddr, u32 rkey, int acc);
+int rvt_lkey_ok(struct rvt_lkey_table *rkt, struct rvt_pd *pd,
+		struct rvt_sge *isge, struct ib_sge *sge, int acc);
 
 #endif          /* DEF_RDMA_VT_H */