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

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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>
This commit is contained in:
Roland Dreier
2007-03-04 16:15:11 -08:00
parent 36f021b579
commit f7c6a7b5d5
20 changed files with 357 additions and 204 deletions
Download Patch File Download Diff File Expand all files Collapse all files

60
drivers/infiniband/core/uverbs_cmd.c
View File

@@ -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;