[PATCH rdma-next 04/10] RDMA/uverbs: Add ioctl command to get a device context

Yishai Hadas
2020-01-08T18:06:20Z

From: Jason Gunthorpe <jgg@mellanox.com>

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.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
drivers/infiniband/core/uverbs.h | 3 +
drivers/infiniband/core/uverbs_cmd.c | 132 ++++++++++++---------
drivers/infiniband/core/uverbs_main.c | 9 +-
.../infiniband/core/uverbs_std_types_async_fd.c | 2 -
drivers/infiniband/core/uverbs_std_types_device.c | 30 +++++
include/uapi/rdma/ib_user_ioctl_cmds.h | 5 +
6 files changed, 119 insertions(+), 62 deletions(-)

diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index aaa5c75..4d4cec4 100644
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -220,6 +220,9 @@ struct ib_ucq_object {
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
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -203,104 +203,118 @@ struct ib_udata *uverbs_get_cleared_udata(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
--- 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 @@ void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
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
--- 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
--- 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 @@ static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_PORT)(
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
--- 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,
--
1.8.3.1