RDMA/uverbs: Add ioctl command to get a device context

Allow future extensions of the get context command through the uverbs
ioctl kabi.

Unlike the uverbs version this does not return an async_fd as well, that
has to be done with another command.

Link: https://lore.kernel.org/r/1578506740-22188-5-git-send-email-yishaih@mellanox.com
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index aaa5c75..4d4cec4 100644 (file)
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -220,6 +220,9 @@ void ib_uverbs_init_async_event_file(struct ib_uverbs_async_event_file *ev_file)
 void ib_uverbs_free_event_queue(struct ib_uverbs_event_queue *event_queue);
 void ib_uverbs_flow_resources_free(struct ib_uflow_resources *uflow_res);
 
+int ib_alloc_ucontext(struct uverbs_attr_bundle *attrs);
+int ib_init_ucontext(struct uverbs_attr_bundle *attrs);
+
 void ib_uverbs_release_ucq(struct ib_uverbs_completion_event_file *ev_file,
                           struct ib_ucq_object *uobj);
 void ib_uverbs_release_uevent(struct ib_uevent_object *uobj);

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index d71ffe4..c8693f5 100644 (file)
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -203,104 +203,118 @@ _ib_uverbs_lookup_comp_file(s32 fd, struct uverbs_attr_bundle *attrs)
 #define ib_uverbs_lookup_comp_file(_fd, _ufile)                                \
        _ib_uverbs_lookup_comp_file((_fd)*typecheck(s32, _fd), _ufile)
 
-static int ib_uverbs_get_context(struct uverbs_attr_bundle *attrs)
+int ib_alloc_ucontext(struct uverbs_attr_bundle *attrs)
 {
-       struct ib_uverbs_file *file = attrs->ufile;
-       struct ib_uverbs_get_context      cmd;
-       struct ib_uverbs_get_context_resp resp;
-       struct ib_ucontext               *ucontext;
-       struct ib_rdmacg_object          cg_obj;
+       struct ib_uverbs_file *ufile = attrs->ufile;
+       struct ib_ucontext *ucontext;
        struct ib_device *ib_dev;
-       struct ib_uobject *uobj;
-       int ret;
 
-       ret = uverbs_request(attrs, &cmd, sizeof(cmd));
-       if (ret)
-               return ret;
+       ib_dev = srcu_dereference(ufile->device->ib_dev,
+                                 &ufile->device->disassociate_srcu);
+       if (!ib_dev)
+               return -EIO;
+
+       ucontext = rdma_zalloc_drv_obj(ib_dev, ib_ucontext);
+       if (!ucontext)
+               return -ENOMEM;
+
+       ucontext->res.type = RDMA_RESTRACK_CTX;
+       ucontext->device = ib_dev;
+       ucontext->ufile = ufile;
+       xa_init_flags(&ucontext->mmap_xa, XA_FLAGS_ALLOC);
+       attrs->context = ucontext;
+       return 0;
+}
+
+int ib_init_ucontext(struct uverbs_attr_bundle *attrs)
+{
+       struct ib_ucontext *ucontext = attrs->context;
+       struct ib_uverbs_file *file = attrs->ufile;
+       int ret;
 
        if (!down_read_trylock(&file->hw_destroy_rwsem))
                return -EIO;
        mutex_lock(&file->ucontext_lock);
-       ib_dev = srcu_dereference(file->device->ib_dev,
-                                 &file->device->disassociate_srcu);
-       if (!ib_dev) {
-               ret = -EIO;
-               goto err;
-       }
-
        if (file->ucontext) {
                ret = -EINVAL;
                goto err;
        }
 
-       ret = ib_rdmacg_try_charge(&cg_obj, ib_dev, RDMACG_RESOURCE_HCA_HANDLE);
+       ret = ib_rdmacg_try_charge(&ucontext->cg_obj, ucontext->device,
+                                  RDMACG_RESOURCE_HCA_HANDLE);
        if (ret)
                goto err;
 
-       ucontext = rdma_zalloc_drv_obj(ib_dev, ib_ucontext);
-       if (!ucontext) {
-               ret = -ENOMEM;
-               goto err_alloc;
-       }
+       ret = ucontext->device->ops.alloc_ucontext(ucontext,
+                                                  &attrs->driver_udata);
+       if (ret)
+               goto err_uncharge;
 
-       attrs->context = ucontext;
+       rdma_restrack_uadd(&ucontext->res);
 
-       ucontext->res.type = RDMA_RESTRACK_CTX;
-       ucontext->device = ib_dev;
-       ucontext->cg_obj = cg_obj;
-       /* ufile is required when some objects are released */
-       ucontext->ufile = file;
+       /*
+        * Make sure that ib_uverbs_get_ucontext() sees the pointer update
+        * only after all writes to setup the ucontext have completed
+        */
+       smp_store_release(&file->ucontext, ucontext);
+
+       mutex_unlock(&file->ucontext_lock);
+       up_read(&file->hw_destroy_rwsem);
+       return 0;
 
-       ucontext->closing = false;
-       ucontext->cleanup_retryable = false;
+err_uncharge:
+       ib_rdmacg_uncharge(&ucontext->cg_obj, ucontext->device,
+                          RDMACG_RESOURCE_HCA_HANDLE);
+err:
+       mutex_unlock(&file->ucontext_lock);
+       up_read(&file->hw_destroy_rwsem);
+       return ret;
+}
 
-       xa_init_flags(&ucontext->mmap_xa, XA_FLAGS_ALLOC);
+static int ib_uverbs_get_context(struct uverbs_attr_bundle *attrs)
+{
+       struct ib_uverbs_get_context_resp resp;
+       struct ib_uverbs_get_context cmd;
+       struct ib_device *ib_dev;
+       struct ib_uobject *uobj;
+       int ret;
+
+       ret = uverbs_request(attrs, &cmd, sizeof(cmd));
+       if (ret)
+               return ret;
+
+       ret = ib_alloc_ucontext(attrs);
+       if (ret)
+               return ret;
 
        uobj = uobj_alloc(UVERBS_OBJECT_ASYNC_EVENT, attrs, &ib_dev);
        if (IS_ERR(uobj)) {
                ret = PTR_ERR(uobj);
-               goto err_free;
+               goto err_ucontext;
        }
 
-       resp.async_fd = uobj->id;
-       resp.num_comp_vectors = file->device->num_comp_vectors;
-
+       resp = (struct ib_uverbs_get_context_resp){
+               .num_comp_vectors = attrs->ufile->device->num_comp_vectors,
+               .async_fd = uobj->id,
+       };
        ret = uverbs_response(attrs, &resp, sizeof(resp));
        if (ret)
                goto err_uobj;
 
-       ret = ib_dev->ops.alloc_ucontext(ucontext, &attrs->driver_udata);
+       ret = ib_init_ucontext(attrs);
        if (ret)
                goto err_uobj;
 
-       rdma_restrack_uadd(&ucontext->res);
-
        ib_uverbs_init_async_event_file(
                container_of(uobj, struct ib_uverbs_async_event_file, uobj));
        rdma_alloc_commit_uobject(uobj, attrs);
-
-       /*
-        * Make sure that ib_uverbs_get_ucontext() sees the pointer update
-        * only after all writes to setup the ucontext have completed
-        */
-       smp_store_release(&file->ucontext, ucontext);
-
-       mutex_unlock(&file->ucontext_lock);
-       up_read(&file->hw_destroy_rwsem);
        return 0;
 
 err_uobj:
        rdma_alloc_abort_uobject(uobj, attrs);
-
-err_free:
-       kfree(ucontext);
-
-err_alloc:
-       ib_rdmacg_uncharge(&cg_obj, ib_dev, RDMACG_RESOURCE_HCA_HANDLE);
-
-err:
-       mutex_unlock(&file->ucontext_lock);
-       up_read(&file->hw_destroy_rwsem);
+err_ucontext:
+       kfree(attrs->context);
+       attrs->context = NULL;
        return ret;
 }
 

diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index fb9e752..2d4083b 100644 (file)
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -150,6 +150,9 @@ void ib_uverbs_release_uevent(struct ib_uevent_object *uobj)
                READ_ONCE(uobj->uobject.ufile->async_file);
        struct ib_uverbs_event *evt, *tmp;
 
+       if (!async_file)
+               return;
+
        spin_lock_irq(&async_file->ev_queue.lock);
        list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
                list_del(&evt->list);
@@ -391,6 +394,9 @@ ib_uverbs_async_handler(struct ib_uverbs_async_event_file *async_file,
        struct ib_uverbs_event *entry;
        unsigned long flags;
 
+       if (!async_file)
+               return;
+
        spin_lock_irqsave(&async_file->ev_queue.lock, flags);
        if (async_file->ev_queue.is_closed) {
                spin_unlock_irqrestore(&async_file->ev_queue.lock, flags);
@@ -476,12 +482,13 @@ void ib_uverbs_init_async_event_file(
        ib_uverbs_init_event_queue(&async_file->ev_queue);
 
        /* The first async_event_file becomes the default one for the file. */
-       lockdep_assert_held(&uverbs_file->ucontext_lock);
+       mutex_lock(&uverbs_file->ucontext_lock);
        if (!uverbs_file->async_file) {
                /* Pairs with the put in ib_uverbs_release_file */
                uverbs_uobject_get(&async_file->uobj);
                smp_store_release(&uverbs_file->async_file, async_file);
        }
+       mutex_unlock(&uverbs_file->ucontext_lock);
 
        INIT_IB_EVENT_HANDLER(&async_file->event_handler, ib_dev,
                              ib_uverbs_event_handler);

diff --git a/drivers/infiniband/core/uverbs_std_types_async_fd.c b/drivers/infiniband/core/uverbs_std_types_async_fd.c
index 484dba1..82ec080 100644 (file)
--- a/drivers/infiniband/core/uverbs_std_types_async_fd.c
+++ b/drivers/infiniband/core/uverbs_std_types_async_fd.c
@@ -14,10 +14,8 @@ static int UVERBS_HANDLER(UVERBS_METHOD_ASYNC_EVENT_ALLOC)(
        struct ib_uobject *uobj =
                uverbs_attr_get_uobject(attrs, UVERBS_METHOD_ASYNC_EVENT_ALLOC);
 
-       mutex_lock(&attrs->ufile->ucontext_lock);
        ib_uverbs_init_async_event_file(
                container_of(uobj, struct ib_uverbs_async_event_file, uobj));
-       mutex_unlock(&attrs->ufile->ucontext_lock);
        return 0;
 }
 

diff --git a/drivers/infiniband/core/uverbs_std_types_device.c b/drivers/infiniband/core/uverbs_std_types_device.c
index 2a3f2f0..2c59435 100644 (file)
--- a/drivers/infiniband/core/uverbs_std_types_device.c
+++ b/drivers/infiniband/core/uverbs_std_types_device.c
@@ -200,6 +200,35 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_PORT)(
                                             &resp, sizeof(resp));
 }
 
+static int UVERBS_HANDLER(UVERBS_METHOD_GET_CONTEXT)(
+       struct uverbs_attr_bundle *attrs)
+{
+       u32 num_comp = attrs->ufile->device->num_comp_vectors;
+       int ret;
+
+       ret = uverbs_copy_to(attrs, UVERBS_ATTR_GET_CONTEXT_NUM_COMP_VECTORS,
+                            &num_comp, sizeof(num_comp));
+       if (IS_UVERBS_COPY_ERR(ret))
+               return ret;
+
+       ret = ib_alloc_ucontext(attrs);
+       if (ret)
+               return ret;
+       ret = ib_init_ucontext(attrs);
+       if (ret) {
+               kfree(attrs->context);
+               attrs->context = NULL;
+               return ret;
+       }
+       return 0;
+}
+
+DECLARE_UVERBS_NAMED_METHOD(
+       UVERBS_METHOD_GET_CONTEXT,
+       UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_GET_CONTEXT_NUM_COMP_VECTORS,
+                           UVERBS_ATTR_TYPE(u32), UA_OPTIONAL),
+       UVERBS_ATTR_UHW());
+
 DECLARE_UVERBS_NAMED_METHOD(
        UVERBS_METHOD_INFO_HANDLES,
        /* Also includes any device specific object ids */
@@ -220,6 +249,7 @@ DECLARE_UVERBS_NAMED_METHOD(
                UA_MANDATORY));
 
 DECLARE_UVERBS_GLOBAL_METHODS(UVERBS_OBJECT_DEVICE,
+                             &UVERBS_METHOD(UVERBS_METHOD_GET_CONTEXT),
                              &UVERBS_METHOD(UVERBS_METHOD_INVOKE_WRITE),
                              &UVERBS_METHOD(UVERBS_METHOD_INFO_HANDLES),
                              &UVERBS_METHOD(UVERBS_METHOD_QUERY_PORT));

diff --git a/include/uapi/rdma/ib_user_ioctl_cmds.h b/include/uapi/rdma/ib_user_ioctl_cmds.h
index 498955c..da6c63c 100644 (file)
--- a/include/uapi/rdma/ib_user_ioctl_cmds.h
+++ b/include/uapi/rdma/ib_user_ioctl_cmds.h
@@ -68,6 +68,7 @@ enum uverbs_methods_device {
        UVERBS_METHOD_INVOKE_WRITE,
        UVERBS_METHOD_INFO_HANDLES,
        UVERBS_METHOD_QUERY_PORT,
+       UVERBS_METHOD_GET_CONTEXT,
 };
 
 enum uverbs_attrs_invoke_write_cmd_attr_ids {
@@ -81,6 +82,10 @@ enum uverbs_attrs_query_port_cmd_attr_ids {
        UVERBS_ATTR_QUERY_PORT_RESP,
 };
 
+enum uverbs_attrs_get_context_attr_ids {
+       UVERBS_ATTR_GET_CONTEXT_NUM_COMP_VECTORS,
+};
+
 enum uverbs_attrs_create_cq_cmd_attr_ids {
        UVERBS_ATTR_CREATE_CQ_HANDLE,
        UVERBS_ATTR_CREATE_CQ_CQE,