IB/uverbs: Export ib_umem_get()/ib_umem_release() to modules

Export ib_umem_get()/ib_umem_release() and put low-level drivers in
control of when to call ib_umem_get() to pin and DMA map userspace,
rather than always calling it in ib_uverbs_reg_mr() before calling the
low-level driver's reg_user_mr method.

Also move these functions to be in the ib_core module instead of
ib_uverbs, so that driver modules using them do not depend on
ib_uverbs.

This has a number of advantages:
 - It is better design from the standpoint of making generic code a
   library that can be used or overridden by device-specific code as
   the details of specific devices dictate.
 - Drivers that do not need to pin userspace memory regions do not
   need to take the performance hit of calling ib_mem_get().  For
   example, although I have not tried to implement it in this patch,
   the ipath driver should be able to avoid pinning memory and just
   use copy_{to,from}_user() to access userspace memory regions.
 - Buffers that need special mapping treatment can be identified by
   the low-level driver.  For example, it may be possible to solve
   some Altix-specific memory ordering issues with mthca CQs in
   userspace by mapping CQ buffers with extra flags.
 - Drivers that need to pin and DMA map userspace memory for things
   other than memory regions can use ib_umem_get() directly, instead
   of hacks using extra parameters to their reg_phys_mr method.  For
   example, the mlx4 driver that is pending being merged needs to pin
   and DMA map QP and CQ buffers, but it does not need to create a
   memory key for these buffers.  So the cleanest solution is for mlx4
   to call ib_umem_get() in the create_qp and create_cq methods.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

18 files changed, 273 insertions, 178 deletions

diff --git a/drivers/infiniband/Kconfig b/drivers/infiniband/Kconfig
index 66b36de9fa6f..82afba5c0bf4 100644
--- a/drivers/infiniband/Kconfig
+++ b/drivers/infiniband/Kconfig
@@ -29,6 +29,11 @@ config INFINIBAND_USER_ACCESS
           libibverbs, libibcm and a hardware driver library from
           <http://www.openib.org>.
 
+config INFINIBAND_USER_MEM
+        bool
+        depends on INFINIBAND_USER_ACCESS != n
+        default y
+
 config INFINIBAND_ADDR_TRANS
         bool
         depends on INFINIBAND && INET
diff --git a/drivers/infiniband/core/Makefile b/drivers/infiniband/core/Makefile
index 189e5d4b9b17..cb1ab3ea4998 100644
--- a/drivers/infiniband/core/Makefile
+++ b/drivers/infiniband/core/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_INFINIBAND_USER_ACCESS) +=	ib_uverbs.o ib_ucm.o \
 
 ib_core-y :=                    packer.o ud_header.o verbs.o sysfs.o \
                                 device.o fmr_pool.o cache.o
+ib_core-$(CONFIG_INFINIBAND_USER_MEM) += umem.o
 
 ib_mad-y :=                     mad.o smi.o agent.o mad_rmpp.o
 
@@ -28,5 +29,4 @@ ib_umad-y :=			user_mad.o
 
 ib_ucm-y :=                     ucm.o
 
-ib_uverbs-y :=                  uverbs_main.o uverbs_cmd.o uverbs_mem.o \
-                                uverbs_marshall.o
+ib_uverbs-y :=                  uverbs_main.o uverbs_cmd.o uverbs_marshall.o
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 7fabb425b033..592c90aa3183 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -613,6 +613,8 @@ static void __exit ib_core_cleanup(void)
 {
         ib_cache_cleanup();
         ib_sysfs_cleanup();
+        /* Make sure that any pending umem accounting work is done. */
+        flush_scheduled_work();
 }
 
 module_init(ib_core_init);
diff --git a/drivers/infiniband/core/uverbs_mem.c b/drivers/infiniband/core/umem.c
index c95fe952abd5..48e854cf416f 100644
--- a/drivers/infiniband/core/uverbs_mem.c
+++ b/drivers/infiniband/core/umem.c
@@ -64,35 +64,56 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d
         }
 }
 
-int ib_umem_get(struct ib_device *dev, struct ib_umem *mem,
-                void *addr, size_t size, int write)
+/**
+ * ib_umem_get - Pin and DMA map userspace memory.
+ * @context: userspace context to pin memory for
+ * @addr: userspace virtual address to start at
+ * @size: length of region to pin
+ * @access: IB_ACCESS_xxx flags for memory being pinned
+ */
+struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
+                            size_t size, int access)
 {
+        struct ib_umem *umem;
         struct page **page_list;
         struct ib_umem_chunk *chunk;
         unsigned long locked;
         unsigned long lock_limit;
         unsigned long cur_base;
         unsigned long npages;
-        int ret = 0;
+        int ret;
         int off;
         int i;
 
         if (!can_do_mlock())
-                return -EPERM;
+                return ERR_PTR(-EPERM);
 
-        page_list = (struct page **) __get_free_page(GFP_KERNEL);
-        if (!page_list)
-                return -ENOMEM;
+        umem = kmalloc(sizeof *umem, GFP_KERNEL);
+        if (!umem)
+                return ERR_PTR(-ENOMEM);
 
-        mem->user_base = (unsigned long) addr;
-        mem->length    = size;
-        mem->offset    = (unsigned long) addr & ~PAGE_MASK;
-        mem->page_size = PAGE_SIZE;
-        mem->writable  = write;
+        umem->context   = context;
+        umem->length    = size;
+        umem->offset    = addr & ~PAGE_MASK;
+        umem->page_size = PAGE_SIZE;
+        /*
+         * We ask for writable memory if any access flags other than
+         * "remote read" are set.  "Local write" and "remote write"
+         * obviously require write access.  "Remote atomic" can do
+         * things like fetch and add, which will modify memory, and
+         * "MW bind" can change permissions by binding a window.
+         */
+        umem->writable  = !!(access & ~IB_ACCESS_REMOTE_READ);
 
-        INIT_LIST_HEAD(&mem->chunk_list);
+        INIT_LIST_HEAD(&umem->chunk_list);
+
+        page_list = (struct page **) __get_free_page(GFP_KERNEL);
+        if (!page_list) {
+                kfree(umem);
+                return ERR_PTR(-ENOMEM);
+        }
 
-        npages = PAGE_ALIGN(size + mem->offset) >> PAGE_SHIFT;
+        npages = PAGE_ALIGN(size + umem->offset) >> PAGE_SHIFT;
 
         down_write(&current->mm->mmap_sem);
 
@@ -104,13 +125,13 @@ int ib_umem_get(struct ib_device *dev, struct ib_umem *mem,
                 goto out;
         }
 
-        cur_base = (unsigned long) addr & PAGE_MASK;
+        cur_base = addr & PAGE_MASK;
 
         while (npages) {
                 ret = get_user_pages(current, current->mm, cur_base,
                                      min_t(int, npages,
                                            PAGE_SIZE / sizeof (struct page *)),
-                                     1, !write, page_list, NULL);
+                                     1, !umem->writable, page_list, NULL);
 
                 if (ret < 0)
                         goto out;
@@ -136,7 +157,7 @@ int ib_umem_get(struct ib_device *dev, struct ib_umem *mem,
                                 chunk->page_list[i].length = PAGE_SIZE;
                         }
 
-                        chunk->nmap = ib_dma_map_sg(dev,
+                        chunk->nmap = ib_dma_map_sg(context->device,
                                                     &chunk->page_list[0],
                                                     chunk->nents,
                                                     DMA_BIDIRECTIONAL);
@@ -151,33 +172,25 @@ int ib_umem_get(struct ib_device *dev, struct ib_umem *mem,
 
                         ret -= chunk->nents;
                         off += chunk->nents;
-                        list_add_tail(&chunk->list, &mem->chunk_list);
+                        list_add_tail(&chunk->list, &umem->chunk_list);
                 }
 
                 ret = 0;
         }
 
 out:
-        if (ret < 0)
-                __ib_umem_release(dev, mem, 0);
-        else
+        if (ret < 0) {
+                __ib_umem_release(context->device, umem, 0);
+                kfree(umem);
+        } else
                 current->mm->locked_vm = locked;
 
         up_write(&current->mm->mmap_sem);
         free_page((unsigned long) page_list);
 
-        return ret;
-}
-
-void ib_umem_release(struct ib_device *dev, struct ib_umem *umem)
-{
-        __ib_umem_release(dev, umem, 1);
-
-        down_write(&current->mm->mmap_sem);
-        current->mm->locked_vm -=
-                PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
-        up_write(&current->mm->mmap_sem);
+        return ret < 0 ? ERR_PTR(ret) : umem;
 }
+EXPORT_SYMBOL(ib_umem_get);
 
 static void ib_umem_account(struct work_struct *_work)
 {
@@ -191,35 +204,70 @@ static void ib_umem_account(struct work_struct *_work)
         kfree(work);
 }
 
-void ib_umem_release_on_close(struct ib_device *dev, struct ib_umem *umem)
+/**
+ * ib_umem_release - release memory pinned with ib_umem_get
+ * @umem: umem struct to release
+ */
+void ib_umem_release(struct ib_umem *umem)
 {
         struct ib_umem_account_work *work;
+        struct ib_ucontext *context = umem->context;
         struct mm_struct *mm;
+        unsigned long diff;
 
-        __ib_umem_release(dev, umem, 1);
+        __ib_umem_release(umem->context->device, umem, 1);
 
         mm = get_task_mm(current);
         if (!mm)
                 return;
 
+        diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
+        kfree(umem);
+
         /*
          * We may be called with the mm's mmap_sem already held.  This
          * can happen when a userspace munmap() is the call that drops
          * the last reference to our file and calls our release
          * method.  If there are memory regions to destroy, we'll end
-         * up here and not be able to take the mmap_sem.  Therefore we
-         * defer the vm_locked accounting to the system workqueue.
+         * up here and not be able to take the mmap_sem.  In that case
+         * we defer the vm_locked accounting to the system workqueue.
          */
+        if (context->closing && !down_write_trylock(&mm->mmap_sem)) {
+                work = kmalloc(sizeof *work, GFP_KERNEL);
+                if (!work) {
+                        mmput(mm);
+                        return;
+                }
 
-        work = kmalloc(sizeof *work, GFP_KERNEL);
-        if (!work) {
-                mmput(mm);
+                INIT_WORK(&work->work, ib_umem_account);
+                work->mm   = mm;
+                work->diff = diff;
+
+                schedule_work(&work->work);
                 return;
-        }
+        } else
+                down_write(&mm->mmap_sem);
+
+        current->mm->locked_vm -= diff;
+        up_write(&mm->mmap_sem);
+        mmput(mm);
+}
+EXPORT_SYMBOL(ib_umem_release);
+
+int ib_umem_page_count(struct ib_umem *umem)
+{
+        struct ib_umem_chunk *chunk;
+        int shift;
+        int i;
+        int n;
+
+        shift = ilog2(umem->page_size);
 
-        INIT_WORK(&work->work, ib_umem_account);
-        work->mm   = mm;
-        work->diff = PAGE_ALIGN(umem->length + umem->offset) >> PAGE_SHIFT;
+        n = 0;
+        list_for_each_entry(chunk, &umem->chunk_list, list)
+                for (i = 0; i < chunk->nmap; ++i)
+                        n += sg_dma_len(&chunk->page_list[i]) >> shift;
 
-        schedule_work(&work->work);
+        return n;
 }
+EXPORT_SYMBOL(ib_umem_page_count);
diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index 102a59c033ff..c33546f9e961 100644
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -45,6 +45,7 @@
 #include <linux/completion.h>
 
 #include <rdma/ib_verbs.h>
+#include <rdma/ib_umem.h>
 #include <rdma/ib_user_verbs.h>
 
 /*
@@ -163,11 +164,6 @@ void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr);
 void ib_uverbs_event_handler(struct ib_event_handler *handler,
                              struct ib_event *event);
 
-int ib_umem_get(struct ib_device *dev, struct ib_umem *mem,
-                void *addr, size_t size, int write);
-void ib_umem_release(struct ib_device *dev, struct ib_umem *umem);
-void ib_umem_release_on_close(struct ib_device *dev, struct ib_umem *umem);
-
 #define IB_UVERBS_DECLARE_CMD(name)                                     \
         ssize_t ib_uverbs_##name(struct ib_uverbs_file *file,           \
                                  const char __user *buf, int in_len,    \
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index bab66769be14..01d70084aebe 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
- * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
+ * Copyright (c) 2005, 2006, 2007 Cisco Systems.  All rights reserved.
  * Copyright (c) 2005 PathScale, Inc.  All rights reserved.
  * Copyright (c) 2006 Mellanox Technologies.  All rights reserved.
  *
@@ -295,6 +295,7 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file,
         INIT_LIST_HEAD(&ucontext->qp_list);
         INIT_LIST_HEAD(&ucontext->srq_list);
         INIT_LIST_HEAD(&ucontext->ah_list);
+        ucontext->closing = 0;
 
         resp.num_comp_vectors = file->device->num_comp_vectors;
 
@@ -573,7 +574,7 @@ ssize_t ib_uverbs_reg_mr(struct ib_uverbs_file *file,
         struct ib_uverbs_reg_mr      cmd;
         struct ib_uverbs_reg_mr_resp resp;
         struct ib_udata              udata;
-        struct ib_umem_object       *obj;
+        struct ib_uobject           *uobj;
         struct ib_pd                *pd;
         struct ib_mr                *mr;
         int                          ret;
@@ -599,35 +600,21 @@ ssize_t ib_uverbs_reg_mr(struct ib_uverbs_file *file,
             !(cmd.access_flags & IB_ACCESS_LOCAL_WRITE))
                 return -EINVAL;
 
-        obj = kmalloc(sizeof *obj, GFP_KERNEL);
-        if (!obj)
+        uobj = kmalloc(sizeof *uobj, GFP_KERNEL);
+        if (!uobj)
                 return -ENOMEM;
 
-        init_uobj(&obj->uobject, 0, file->ucontext, &mr_lock_key);
-        down_write(&obj->uobject.mutex);
-
-        /*
-         * We ask for writable memory if any access flags other than
-         * "remote read" are set.  "Local write" and "remote write"
-         * obviously require write access.  "Remote atomic" can do
-         * things like fetch and add, which will modify memory, and
-         * "MW bind" can change permissions by binding a window.
-         */
-        ret = ib_umem_get(file->device->ib_dev, &obj->umem,
-                          (void *) (unsigned long) cmd.start, cmd.length,
-                          !!(cmd.access_flags & ~IB_ACCESS_REMOTE_READ));
-        if (ret)
-                goto err_free;
-
-        obj->umem.virt_base = cmd.hca_va;
+        init_uobj(uobj, 0, file->ucontext, &mr_lock_key);
+        down_write(&uobj->mutex);
 
         pd = idr_read_pd(cmd.pd_handle, file->ucontext);
         if (!pd) {
                 ret = -EINVAL;
-                goto err_release;
+                goto err_free;
         }
 
-        mr = pd->device->reg_user_mr(pd, &obj->umem, cmd.access_flags, &udata);
+        mr = pd->device->reg_user_mr(pd, cmd.start, cmd.length, cmd.hca_va,
+                                     cmd.access_flags, &udata);
         if (IS_ERR(mr)) {
                 ret = PTR_ERR(mr);
                 goto err_put;
@@ -635,19 +622,19 @@ ssize_t ib_uverbs_reg_mr(struct ib_uverbs_file *file,
 
         mr->device  = pd->device;
         mr->pd      = pd;
-        mr->uobject = &obj->uobject;
+        mr->uobject = uobj;
         atomic_inc(&pd->usecnt);
         atomic_set(&mr->usecnt, 0);
 
-        obj->uobject.object = mr;
-        ret = idr_add_uobj(&ib_uverbs_mr_idr, &obj->uobject);
+        uobj->object = mr;
+        ret = idr_add_uobj(&ib_uverbs_mr_idr, uobj);
         if (ret)
                 goto err_unreg;
 
         memset(&resp, 0, sizeof resp);
         resp.lkey      = mr->lkey;
         resp.rkey      = mr->rkey;
-        resp.mr_handle = obj->uobject.id;
+        resp.mr_handle = uobj->id;
 
         if (copy_to_user((void __user *) (unsigned long) cmd.response,
                          &resp, sizeof resp)) {
@@ -658,17 +645,17 @@ ssize_t ib_uverbs_reg_mr(struct ib_uverbs_file *file,
         put_pd_read(pd);
 
         mutex_lock(&file->mutex);
-        list_add_tail(&obj->uobject.list, &file->ucontext->mr_list);
+        list_add_tail(&uobj->list, &file->ucontext->mr_list);
         mutex_unlock(&file->mutex);
 
-        obj->uobject.live = 1;
+        uobj->live = 1;
 
-        up_write(&obj->uobject.mutex);
+        up_write(&uobj->mutex);
 
         return in_len;
 
 err_copy:
-        idr_remove_uobj(&ib_uverbs_mr_idr, &obj->uobject);
+        idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
 
 err_unreg:
         ib_dereg_mr(mr);
@@ -676,11 +663,8 @@ err_unreg:
 err_put:
         put_pd_read(pd);
 
-err_release:
-        ib_umem_release(file->device->ib_dev, &obj->umem);
-
 err_free:
-        put_uobj_write(&obj->uobject);
+        put_uobj_write(uobj);
         return ret;
 }
 
@@ -691,7 +675,6 @@ ssize_t ib_uverbs_dereg_mr(struct ib_uverbs_file *file,
         struct ib_uverbs_dereg_mr cmd;
         struct ib_mr             *mr;
         struct ib_uobject        *uobj;
-        struct ib_umem_object    *memobj;
         int                       ret = -EINVAL;
 
         if (copy_from_user(&cmd, buf, sizeof cmd))
@@ -701,8 +684,7 @@ ssize_t ib_uverbs_dereg_mr(struct ib_uverbs_file *file,
         if (!uobj)
                 return -EINVAL;
 
-        memobj = container_of(uobj, struct ib_umem_object, uobject);
-        mr     = uobj->object;
+        mr = uobj->object;
 
         ret = ib_dereg_mr(mr);
         if (!ret)
@@ -719,8 +701,6 @@ ssize_t ib_uverbs_dereg_mr(struct ib_uverbs_file *file,
         list_del(&uobj->list);
         mutex_unlock(&file->mutex);
 
-        ib_umem_release(file->device->ib_dev, &memobj->umem);
-
         put_uobj(uobj);
 
         return in_len;
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index d44e54799651..14d7ccd89195 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -183,6 +183,8 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
         if (!context)
                 return 0;
 
+        context->closing = 1;
+
         list_for_each_entry_safe(uobj, tmp, &context->ah_list, list) {
                 struct ib_ah *ah = uobj->object;
 
@@ -230,16 +232,10 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file,
 
         list_for_each_entry_safe(uobj, tmp, &context->mr_list, list) {
                 struct ib_mr *mr = uobj->object;
-                struct ib_device *mrdev = mr->device;
-                struct ib_umem_object *memobj;
 
                 idr_remove_uobj(&ib_uverbs_mr_idr, uobj);
                 ib_dereg_mr(mr);
-
-                memobj = container_of(uobj, struct ib_umem_object, uobject);
-                ib_umem_release_on_close(mrdev, &memobj->umem);
-
-                kfree(memobj);
+                kfree(uobj);
         }
 
         list_for_each_entry_safe(uobj, tmp, &context->pd_list, list) {
@@ -906,7 +902,6 @@ static void __exit ib_uverbs_cleanup(void)
         unregister_filesystem(&uverbs_event_fs);
         class_destroy(uverbs_class);
         unregister_chrdev_region(IB_UVERBS_BASE_DEV, IB_UVERBS_MAX_DEVICES);
-        flush_scheduled_work();
         idr_destroy(&ib_uverbs_pd_idr);
         idr_destroy(&ib_uverbs_mr_idr);
         idr_destroy(&ib_uverbs_mw_idr);
diff --git a/drivers/infiniband/hw/amso1100/c2_provider.c b/drivers/infiniband/hw/amso1100/c2_provider.c
index 109166223c09..997cf1530762 100644
--- a/drivers/infiniband/hw/amso1100/c2_provider.c
+++ b/drivers/infiniband/hw/amso1100/c2_provider.c
@@ -56,6 +56,7 @@
 #include <asm/byteorder.h>
 
 #include <rdma/ib_smi.h>
+#include <rdma/ib_umem.h>
 #include <rdma/ib_user_verbs.h>
 #include "c2.h"
 #include "c2_provider.h"
@@ -396,6 +397,7 @@ static struct ib_mr *c2_reg_phys_mr(struct ib_pd *ib_pd,
         }
 
         mr->pd = to_c2pd(ib_pd);
+        mr->umem = NULL;
         pr_debug("%s - page shift %d, pbl_depth %d, total_len %u, "
                 "*iova_start %llx, first pa %llx, last pa %llx\n",
                 __FUNCTION__, page_shift, pbl_depth, total_len,
@@ -428,8 +430,8 @@ static struct ib_mr *c2_get_dma_mr(struct ib_pd *pd, int acc)
         return c2_reg_phys_mr(pd, &bl, 1, acc, &kva);
 }
 
-static struct ib_mr *c2_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
-                                    int acc, struct ib_udata *udata)
+static struct ib_mr *c2_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
+                                    u64 virt, int acc, struct ib_udata *udata)
 {
         u64 *pages;
         u64 kva = 0;
@@ -441,15 +443,23 @@ static struct ib_mr *c2_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
         struct c2_mr *c2mr;
 
         pr_debug("%s:%u\n", __FUNCTION__, __LINE__);
-        shift = ffs(region->page_size) - 1;
 
         c2mr = kmalloc(sizeof(*c2mr), GFP_KERNEL);
         if (!c2mr)
                 return ERR_PTR(-ENOMEM);
         c2mr->pd = c2pd;
 
+        c2mr->umem = ib_umem_get(pd->uobject->context, start, length, acc);
+        if (IS_ERR(c2mr->umem)) {
+                err = PTR_ERR(c2mr->umem);
+                kfree(c2mr);
+                return ERR_PTR(err);
+        }
+
+        shift = ffs(c2mr->umem->page_size) - 1;
+
         n = 0;
-        list_for_each_entry(chunk, &region->chunk_list, list)
+        list_for_each_entry(chunk, &c2mr->umem->chunk_list, list)
                 n += chunk->nents;
 
         pages = kmalloc(n * sizeof(u64), GFP_KERNEL);
@@ -459,35 +469,34 @@ static struct ib_mr *c2_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
         }
 
         i = 0;
-        list_for_each_entry(chunk, &region->chunk_list, list) {
+        list_for_each_entry(chunk, &c2mr->umem->chunk_list, list) {
                 for (j = 0; j < chunk->nmap; ++j) {
                         len = sg_dma_len(&chunk->page_list[j]) >> shift;
                         for (k = 0; k < len; ++k) {
                                 pages[i++] =
                                         sg_dma_address(&chunk->page_list[j]) +
-                                        (region->page_size * k);
+                                        (c2mr->umem->page_size * k);
                         }
                 }
         }
 
-        kva = (u64)region->virt_base;
+        kva = virt;
         err = c2_nsmr_register_phys_kern(to_c2dev(pd->device),
                                          pages,
-                                         region->page_size,
+                                         c2mr->umem->page_size,
                                          i,
-                                         region->length,
-                                         region->offset,
+                                         length,
+                                         c2mr->umem->offset,
                                          &kva,
                                          c2_convert_access(acc),
                                          c2mr);
         kfree(pages);
-        if (err) {
-                kfree(c2mr);
-                return ERR_PTR(err);
-        }
+        if (err)
+                goto err;
         return &c2mr->ibmr;
 
 err:
+        ib_umem_release(c2mr->umem);
         kfree(c2mr);
         return ERR_PTR(err);
 }
@@ -502,8 +511,11 @@ static int c2_dereg_mr(struct ib_mr *ib_mr)
         err = c2_stag_dealloc(to_c2dev(ib_mr->device), ib_mr->lkey);
         if (err)
                 pr_debug("c2_stag_dealloc failed: %d\n", err);
-        else
+        else {
+                if (mr->umem)
+                        ib_umem_release(mr->umem);
                 kfree(mr);
+        }
 
         return err;
 }
diff --git a/drivers/infiniband/hw/amso1100/c2_provider.h b/drivers/infiniband/hw/amso1100/c2_provider.h
index fc906223220f..1076df2ee96a 100644
--- a/drivers/infiniband/hw/amso1100/c2_provider.h
+++ b/drivers/infiniband/hw/amso1100/c2_provider.h
@@ -73,6 +73,7 @@ struct c2_pd {
 struct c2_mr {
         struct ib_mr ibmr;
         struct c2_pd *pd;
+        struct ib_umem *umem;
 };
 
 struct c2_av;
diff --git a/drivers/infiniband/hw/cxgb3/iwch_provider.c b/drivers/infiniband/hw/cxgb3/iwch_provider.c
index a891493fd340..e7c2c3948037 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_provider.c
+++ b/drivers/infiniband/hw/cxgb3/iwch_provider.c
@@ -47,6 +47,7 @@
 #include <rdma/iw_cm.h>
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_smi.h>
+#include <rdma/ib_umem.h>
 #include <rdma/ib_user_verbs.h>
 
 #include "cxio_hal.h"
@@ -443,6 +444,8 @@ static int iwch_dereg_mr(struct ib_mr *ib_mr)
         remove_handle(rhp, &rhp->mmidr, mmid);
         if (mhp->kva)
                 kfree((void *) (unsigned long) mhp->kva);
+        if (mhp->umem)
+                ib_umem_release(mhp->umem);
         PDBG("%s mmid 0x%x ptr %p\n", __FUNCTION__, mmid, mhp);
         kfree(mhp);
         return 0;
@@ -577,8 +580,8 @@ static int iwch_reregister_phys_mem(struct ib_mr *mr,
 }
 
 
-static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
-                                      int acc, struct ib_udata *udata)
+static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
+                                      u64 virt, int acc, struct ib_udata *udata)
 {
         __be64 *pages;
         int shift, n, len;
@@ -591,7 +594,6 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
         struct iwch_reg_user_mr_resp uresp;
 
         PDBG("%s ib_pd %p\n", __FUNCTION__, pd);
-        shift = ffs(region->page_size) - 1;
 
         php = to_iwch_pd(pd);
         rhp = php->rhp;
@@ -599,8 +601,17 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
         if (!mhp)
                 return ERR_PTR(-ENOMEM);
 
+        mhp->umem = ib_umem_get(pd->uobject->context, start, length, acc);
+        if (IS_ERR(mhp->umem)) {
+                err = PTR_ERR(mhp->umem);
+                kfree(mhp);
+                return ERR_PTR(err);
+        }
+
+        shift = ffs(mhp->umem->page_size) - 1;
+
         n = 0;
-        list_for_each_entry(chunk, &region->chunk_list, list)
+        list_for_each_entry(chunk, &mhp->umem->chunk_list, list)
                 n += chunk->nents;
 
         pages = kmalloc(n * sizeof(u64), GFP_KERNEL);
@@ -611,13 +622,13 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
 
         i = n = 0;
 
-        list_for_each_entry(chunk, &region->chunk_list, list)
+        list_for_each_entry(chunk, &mhp->umem->chunk_list, list)
                 for (j = 0; j < chunk->nmap; ++j) {
                         len = sg_dma_len(&chunk->page_list[j]) >> shift;
                         for (k = 0; k < len; ++k) {
                                 pages[i++] = cpu_to_be64(sg_dma_address(
                                         &chunk->page_list[j]) +
-                                        region->page_size * k);
+                                        mhp->umem->page_size * k);
                         }
                 }
 
@@ -625,9 +636,9 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
         mhp->attr.pdid = php->pdid;
         mhp->attr.zbva = 0;
         mhp->attr.perms = iwch_ib_to_tpt_access(acc);
-        mhp->attr.va_fbo = region->virt_base;
+        mhp->attr.va_fbo = virt;
         mhp->attr.page_size = shift - 12;
-        mhp->attr.len = (u32) region->length;
+        mhp->attr.len = (u32) length;
         mhp->attr.pbl_size = i;
         err = iwch_register_mem(rhp, php, mhp, shift, pages);
         kfree(pages);
@@ -650,6 +661,7 @@ static struct ib_mr *iwch_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
         return &mhp->ibmr;
 
 err:
+        ib_umem_release(mhp->umem);
         kfree(mhp);
         return ERR_PTR(err);
 }
diff --git a/drivers/infiniband/hw/cxgb3/iwch_provider.h b/drivers/infiniband/hw/cxgb3/iwch_provider.h
index 93bcc56756bd..48833f3f3bd0 100644
--- a/drivers/infiniband/hw/cxgb3/iwch_provider.h
+++ b/drivers/infiniband/hw/cxgb3/iwch_provider.h
@@ -73,6 +73,7 @@ struct tpt_attributes {
 
 struct iwch_mr {
         struct ib_mr ibmr;
+        struct ib_umem *umem;
         struct iwch_dev *rhp;
         u64 kva;
         struct tpt_attributes attr;
diff --git a/drivers/infiniband/hw/ehca/ehca_classes.h b/drivers/infiniband/hw/ehca/ehca_classes.h
index 10fb8fbafa0c..f64d42b08674 100644
--- a/drivers/infiniband/hw/ehca/ehca_classes.h
+++ b/drivers/infiniband/hw/ehca/ehca_classes.h
@@ -176,6 +176,7 @@ struct ehca_mr {
                 struct ib_mr ib_mr;     /* must always be first in ehca_mr */
                 struct ib_fmr ib_fmr;   /* must always be first in ehca_mr */
         } ib;
+        struct ib_umem *umem;
         spinlock_t mrlock;
 
         enum ehca_mr_flag flags;
diff --git a/drivers/infiniband/hw/ehca/ehca_iverbs.h b/drivers/infiniband/hw/ehca/ehca_iverbs.h
index e14b029332c8..37e7fe0908cf 100644
--- a/drivers/infiniband/hw/ehca/ehca_iverbs.h
+++ b/drivers/infiniband/hw/ehca/ehca_iverbs.h
@@ -78,8 +78,7 @@ struct ib_mr *ehca_reg_phys_mr(struct ib_pd *pd,
                                int num_phys_buf,
                                int mr_access_flags, u64 *iova_start);
 
-struct ib_mr *ehca_reg_user_mr(struct ib_pd *pd,
-                               struct ib_umem *region,
+struct ib_mr *ehca_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, u64 virt,
                                int mr_access_flags, struct ib_udata *udata);
 
 int ehca_rereg_phys_mr(struct ib_mr *mr,
diff --git a/drivers/infiniband/hw/ehca/ehca_mrmw.c b/drivers/infiniband/hw/ehca/ehca_mrmw.c
index d22ab563633f..84c5bb498563 100644
--- a/drivers/infiniband/hw/ehca/ehca_mrmw.c
+++ b/drivers/infiniband/hw/ehca/ehca_mrmw.c
@@ -39,6 +39,8 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <rdma/ib_umem.h>
+
 #include <asm/current.h>
 
 #include "ehca_iverbs.h"
@@ -238,10 +240,8 @@ reg_phys_mr_exit0:
 
 /*----------------------------------------------------------------------*/
 
-struct ib_mr *ehca_reg_user_mr(struct ib_pd *pd,
-                               struct ib_umem *region,
-                               int mr_access_flags,
-                               struct ib_udata *udata)
+struct ib_mr *ehca_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, u64 virt,
+                               int mr_access_flags, struct ib_udata *udata)
 {
         struct ib_mr *ib_mr;
         struct ehca_mr *e_mr;
@@ -257,11 +257,7 @@ struct ib_mr *ehca_reg_user_mr(struct ib_pd *pd,
                 ehca_gen_err("bad pd=%p", pd);
                 return ERR_PTR(-EFAULT);
         }
-        if (!region) {
-                ehca_err(pd->device, "bad input values: region=%p", region);
-                ib_mr = ERR_PTR(-EINVAL);
-                goto reg_user_mr_exit0;
-        }
+
         if (((mr_access_flags & IB_ACCESS_REMOTE_WRITE) &&
              !(mr_access_flags & IB_ACCESS_LOCAL_WRITE)) ||
             ((mr_access_flags & IB_ACCESS_REMOTE_ATOMIC) &&
@@ -275,17 +271,10 @@ struct ib_mr *ehca_reg_user_mr(struct ib_pd *pd,
                 ib_mr = ERR_PTR(-EINVAL);
                 goto reg_user_mr_exit0;
         }
-        if (region->page_size != PAGE_SIZE) {
-                ehca_err(pd->device, "page size not supported, "
-                         "region->page_size=%x", region->page_size);
-                ib_mr = ERR_PTR(-EINVAL);
-                goto reg_user_mr_exit0;
-        }
 
-        if ((region->length == 0) ||
-            ((region->virt_base + region->length) < region->virt_base)) {
+        if (length == 0 || virt + length < virt) {
                 ehca_err(pd->device, "bad input values: length=%lx "
-                         "virt_base=%lx", region->length, region->virt_base);
+                         "virt_base=%lx", length, virt);
                 ib_mr = ERR_PTR(-EINVAL);
                 goto reg_user_mr_exit0;
         }
@@ -297,40 +286,55 @@ struct ib_mr *ehca_reg_user_mr(struct ib_pd *pd,
                 goto reg_user_mr_exit0;
         }
 
+        e_mr->umem = ib_umem_get(pd->uobject->context, start, length,
+                                 mr_access_flags);
+        if (IS_ERR(e_mr->umem)) {
+                ib_mr = (void *) e_mr->umem;
+                goto reg_user_mr_exit1;
+        }
+
+        if (e_mr->umem->page_size != PAGE_SIZE) {
+                ehca_err(pd->device, "page size not supported, "
+                         "e_mr->umem->page_size=%x", e_mr->umem->page_size);
+                ib_mr = ERR_PTR(-EINVAL);
+                goto reg_user_mr_exit2;
+        }
+
         /* determine number of MR pages */
-        num_pages_mr = (((region->virt_base % PAGE_SIZE) + region->length +
-                         PAGE_SIZE - 1) / PAGE_SIZE);
-        num_pages_4k = (((region->virt_base % EHCA_PAGESIZE) + region->length +
-                         EHCA_PAGESIZE - 1) / EHCA_PAGESIZE);
+        num_pages_mr = (((virt % PAGE_SIZE) + length + PAGE_SIZE - 1) /
+                        PAGE_SIZE);
+        num_pages_4k = (((virt % EHCA_PAGESIZE) + length + EHCA_PAGESIZE - 1) /
+                        EHCA_PAGESIZE);
 
         /* register MR on HCA */
         pginfo.type       = EHCA_MR_PGI_USER;
         pginfo.num_pages  = num_pages_mr;
         pginfo.num_4k     = num_pages_4k;
-        pginfo.region     = region;
-        pginfo.next_4k    = region->offset / EHCA_PAGESIZE;
+        pginfo.region     = e_mr->umem;
+        pginfo.next_4k    = e_mr->umem->offset / EHCA_PAGESIZE;
         pginfo.next_chunk = list_prepare_entry(pginfo.next_chunk,
-                                               (&region->chunk_list),
+                                               (&e_mr->umem->chunk_list),
                                                list);
 
-        ret = ehca_reg_mr(shca, e_mr, (u64*)region->virt_base,
-                          region->length, mr_access_flags, e_pd, &pginfo,
-                          &e_mr->ib.ib_mr.lkey, &e_mr->ib.ib_mr.rkey);
+        ret = ehca_reg_mr(shca, e_mr, (u64*) virt, length, mr_access_flags, e_pd,
+                          &pginfo, &e_mr->ib.ib_mr.lkey, &e_mr->ib.ib_mr.rkey);
         if (ret) {
                 ib_mr = ERR_PTR(ret);
-                goto reg_user_mr_exit1;
+                goto reg_user_mr_exit2;
         }
 
         /* successful registration of all pages */
         return &e_mr->ib.ib_mr;
 
+reg_user_mr_exit2:
+        ib_umem_release(e_mr->umem);
 reg_user_mr_exit1:
         ehca_mr_delete(e_mr);
 reg_user_mr_exit0:
         if (IS_ERR(ib_mr))
-                ehca_err(pd->device, "rc=%lx pd=%p region=%p mr_access_flags=%x"
+                ehca_err(pd->device, "rc=%lx pd=%p mr_access_flags=%x"
                          " udata=%p",
-                         PTR_ERR(ib_mr), pd, region, mr_access_flags, udata);
+                         PTR_ERR(ib_mr), pd, mr_access_flags, udata);
         return ib_mr;
 } /* end ehca_reg_user_mr() */
 
@@ -596,6 +600,9 @@ int ehca_dereg_mr(struct ib_mr *mr)
                 goto dereg_mr_exit0;
         }
 
+        if (e_mr->umem)
+                ib_umem_release(e_mr->umem);
+
         /* successful deregistration */
         ehca_mr_delete(e_mr);
 
diff --git a/drivers/infiniband/hw/ipath/ipath_mr.c b/drivers/infiniband/hw/ipath/ipath_mr.c
index 31e70732e369..bdeef8d4f279 100644
--- a/drivers/infiniband/hw/ipath/ipath_mr.c
+++ b/drivers/infiniband/hw/ipath/ipath_mr.c
@@ -31,6 +31,7 @@
  * SOFTWARE.
  */
 
+#include <rdma/ib_umem.h>
 #include <rdma/ib_pack.h>
 #include <rdma/ib_smi.h>
 
@@ -147,6 +148,7 @@ struct ib_mr *ipath_reg_phys_mr(struct ib_pd *pd,
         mr->mr.offset = 0;
         mr->mr.access_flags = acc;
         mr->mr.max_segs = num_phys_buf;
+        mr->umem = NULL;
 
         m = 0;
         n = 0;
@@ -170,46 +172,56 @@ bail:
 /**
  * ipath_reg_user_mr - register a userspace memory region
  * @pd: protection domain for this memory region
- * @region: the user memory region
+ * @start: starting userspace address
+ * @length: length of region to register
+ * @virt_addr: virtual address to use (from HCA's point of view)
  * @mr_access_flags: access flags for this memory region
  * @udata: unused by the InfiniPath driver
  *
  * Returns the memory region on success, otherwise returns an errno.
  */
-struct ib_mr *ipath_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
-                                int mr_access_flags, struct ib_udata *udata)
+struct ib_mr *ipath_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
+                                u64 virt_addr, int mr_access_flags,
+                                struct ib_udata *udata)
 {
         struct ipath_mr *mr;
+        struct ib_umem *umem;
         struct ib_umem_chunk *chunk;
         int n, m, i;
         struct ib_mr *ret;
 
-        if (region->length == 0) {
+        if (length == 0) {
                 ret = ERR_PTR(-EINVAL);
                 goto bail;
         }
 
+        umem = ib_umem_get(pd->uobject->context, start, length, mr_access_flags);
+        if (IS_ERR(umem))
+                return (void *) umem;
+
         n = 0;
-        list_for_each_entry(chunk, &region->chunk_list, list)
+        list_for_each_entry(chunk, &umem->chunk_list, list)
                 n += chunk->nents;
 
         mr = alloc_mr(n, &to_idev(pd->device)->lk_table);
         if (!mr) {
                 ret = ERR_PTR(-ENOMEM);
+                ib_umem_release(umem);
                 goto bail;
         }
 
         mr->mr.pd = pd;
-        mr->mr.user_base = region->user_base;
-        mr->mr.iova = region->virt_base;
-        mr->mr.length = region->length;
-        mr->mr.offset = region->offset;
+        mr->mr.user_base = start;
+        mr->mr.iova = virt_addr;
+        mr->mr.length = length;
+        mr->mr.offset = umem->offset;
         mr->mr.access_flags = mr_access_flags;
         mr->mr.max_segs = n;
+        mr->umem = umem;
 
         m = 0;
         n = 0;
-        list_for_each_entry(chunk, &region->chunk_list, list) {
+        list_for_each_entry(chunk, &umem->chunk_list, list) {
                 for (i = 0; i < chunk->nents; i++) {
                         void *vaddr;
 
@@ -219,7 +231,7 @@ struct ib_mr *ipath_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
                                 goto bail;
                         }
                         mr->mr.map[m]->segs[n].vaddr = vaddr;
-                        mr->mr.map[m]->segs[n].length = region->page_size;
+                        mr->mr.map[m]->segs[n].length = umem->page_size;
                         n++;
                         if (n == IPATH_SEGSZ) {
                                 m++;
@@ -253,6 +265,10 @@ int ipath_dereg_mr(struct ib_mr *ibmr)
                 i--;
                 kfree(mr->mr.map[i]);
         }
+
+        if (mr->umem)
+                ib_umem_release(mr->umem);
+
         kfree(mr);
         return 0;
 }
diff --git a/drivers/infiniband/hw/ipath/ipath_verbs.h b/drivers/infiniband/hw/ipath/ipath_verbs.h
index 7064fc222727..088b837ebea8 100644
--- a/drivers/infiniband/hw/ipath/ipath_verbs.h
+++ b/drivers/infiniband/hw/ipath/ipath_verbs.h
@@ -251,6 +251,7 @@ struct ipath_sge {
 /* Memory region */
 struct ipath_mr {
         struct ib_mr ibmr;
+        struct ib_umem *umem;
         struct ipath_mregion mr;        /* must be last */
 };
 
@@ -751,8 +752,8 @@ struct ib_mr *ipath_reg_phys_mr(struct ib_pd *pd,
                                 struct ib_phys_buf *buffer_list,
                                 int num_phys_buf, int acc, u64 *iova_start);
 
-struct ib_mr *ipath_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
-                                int mr_access_flags,
+struct ib_mr *ipath_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
+                                u64 virt_addr, int mr_access_flags,
                                 struct ib_udata *udata);
 
 int ipath_dereg_mr(struct ib_mr *ibmr);
diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index 1c05486c3c68..6bcde1cb9688 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -37,6 +37,7 @@
  */
 
 #include <rdma/ib_smi.h>
+#include <rdma/ib_umem.h>
 #include <rdma/ib_user_verbs.h>
 #include <linux/mm.h>
 
@@ -908,6 +909,8 @@ static struct ib_mr *mthca_get_dma_mr(struct ib_pd *pd, int acc)
                 return ERR_PTR(err);
         }
 
+        mr->umem = NULL;
+
         return &mr->ibmr;
 }
 
@@ -1003,11 +1006,13 @@ static struct ib_mr *mthca_reg_phys_mr(struct ib_pd       *pd,
         }
 
         kfree(page_list);
+        mr->umem = NULL;
+
         return &mr->ibmr;
 }
 
-static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
-                                       int acc, struct ib_udata *udata)
+static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
+                                       u64 virt, int acc, struct ib_udata *udata)
 {
         struct mthca_dev *dev = to_mdev(pd->device);
         struct ib_umem_chunk *chunk;
@@ -1018,20 +1023,26 @@ static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
         int err = 0;
         int write_mtt_size;
 
-        shift = ffs(region->page_size) - 1;
-
         mr = kmalloc(sizeof *mr, GFP_KERNEL);
         if (!mr)
                 return ERR_PTR(-ENOMEM);
 
+        mr->umem = ib_umem_get(pd->uobject->context, start, length, acc);
+        if (IS_ERR(mr->umem)) {
+                err = PTR_ERR(mr->umem);
+                goto err;
+        }
+
+        shift = ffs(mr->umem->page_size) - 1;
+
         n = 0;
-        list_for_each_entry(chunk, &region->chunk_list, list)
+        list_for_each_entry(chunk, &mr->umem->chunk_list, list)
                 n += chunk->nents;
 
         mr->mtt = mthca_alloc_mtt(dev, n);
         if (IS_ERR(mr->mtt)) {
                 err = PTR_ERR(mr->mtt);
-                goto err;
+                goto err_umem;
         }
 
         pages = (u64 *) __get_free_page(GFP_KERNEL);
@@ -1044,12 +1055,12 @@ static struct ib_mr *mthca_reg_user_mr(struct ib_pd *pd, struct ib_umem *region,
 
         write_mtt_size = min(mthca_write_mtt_size(dev), (int) (PAGE_SIZE / sizeof *pages));
 
-        list_for_each_entry(chunk, &region->chunk_list, list)
+        list_for_each_entry(chunk, &mr->umem->chunk_list, list)
                 for (j = 0; j < chunk->nmap; ++j) {
                         len = sg_dma_len(&chunk->page_list[j]) >> shift;
                         for (k = 0; k < len; ++k) {
                                 pages[i++] = sg_dma_address(&chunk->page_list[j]) +
-                                        region->page_size * k;
+                                        mr->umem->page_size * k;
                                 /*
                                  * Be friendly to write_mtt and pass it chunks
                                  * of appropriate size.
@@ -1071,8 +1082,8 @@ mtt_done:
         if (err)
                 goto err_mtt;
 
-        err = mthca_mr_alloc(dev, to_mpd(pd)->pd_num, shift, region->virt_base,
-                             region->length, convert_access(acc), mr);
+        err = mthca_mr_alloc(dev, to_mpd(pd)->pd_num, shift, virt, length,
+                             convert_access(acc), mr);
 
         if (err)
                 goto err_mtt;
@@ -1082,6 +1093,9 @@ mtt_done:
 err_mtt:
         mthca_free_mtt(dev, mr->mtt);
 
+err_umem:
+        ib_umem_release(mr->umem);
+
 err:
         kfree(mr);
         return ERR_PTR(err);
@@ -1090,8 +1104,12 @@ err:
 static int mthca_dereg_mr(struct ib_mr *mr)
 {
         struct mthca_mr *mmr = to_mmr(mr);
+
         mthca_free_mr(to_mdev(mr->device), mmr);
+        if (mmr->umem)
+                ib_umem_release(mmr->umem);
         kfree(mmr);
+
         return 0;
 }
 
diff --git a/drivers/infiniband/hw/mthca/mthca_provider.h b/drivers/infiniband/hw/mthca/mthca_provider.h
index 1d266ac2e094..262616c8ebb6 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.h
+++ b/drivers/infiniband/hw/mthca/mthca_provider.h
@@ -73,6 +73,7 @@ struct mthca_mtt;
 
 struct mthca_mr {
         struct ib_mr      ibmr;
+        struct ib_umem   *umem;
         struct mthca_mtt *mtt;
 };