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>
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index bab6676..01d7008 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 @@
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 @@
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 @@
!(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 @@
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 @@
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_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 @@
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 @@
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 @@
list_del(&uobj->list);
mutex_unlock(&file->mutex);
- ib_umem_release(file->device->ib_dev, &memobj->umem);
-
put_uobj(uobj);
return in_len;
