[PATCH rdma-next v3 06/17] RDMA/uverbs: Push out CQ buffer umem processing into a helper

[Jiri Pirko <jiri@resnulli.us>]

From: Jiri Pirko <jiri@nvidia.com>

Extract the UVERBS_ATTR_CREATE_CQ_BUFFER_* parser from the CQ
create handler into uverbs_create_cq_get_buffer_desc(), and wrap
it in ib_umem_get_cq_tmp(), the umem-producing helper the cq_create
handler now calls.

ib_umem_get_cq_tmp() is temporary; subsequent patches replace it
with driver-owned ib_umem_get_cq_buf*() wrappers built on the
same parser, and remove it once all CQ drivers have switched.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
v2->v3:
- renamed uverbs_create_cq_get_umem() to ib_umem_get_cq_tmp() and
  moved to umem.c
- split legacy attr parser into uverbs_create_cq_get_buffer_desc()
  for upcoming ib_umem_get_cq_buf*() reuse
- rebased on top of "RDMA/core: Fix user CQ creation for drivers
  without create_cq"
---
 drivers/infiniband/core/umem.c                | 79 +++++++++++++++++++
 drivers/infiniband/core/uverbs_std_types_cq.c | 60 +-------------
 include/rdma/ib_umem.h                        |  7 ++
 3 files changed, 89 insertions(+), 57 deletions(-)

diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index b0ab4133d47d..f720de8cb162 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -377,6 +377,85 @@ struct ib_umem *ib_umem_get(struct ib_device *device, struct ib_udata *udata,
 }
 EXPORT_SYMBOL(ib_umem_get);
 
+static int uverbs_create_cq_get_buffer_desc(struct uverbs_attr_bundle *attrs,
+					    struct ib_uverbs_buffer_desc *desc)
+{
+	struct ib_device *ib_dev = attrs->context->device;
+	int ret;
+
+	if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_VA)) {
+		ret = uverbs_copy_from(&desc->addr, attrs,
+				       UVERBS_ATTR_CREATE_CQ_BUFFER_VA);
+		if (ret)
+			return ret;
+		ret = uverbs_copy_from(&desc->length, attrs,
+				       UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH);
+		if (ret)
+			return ret;
+		if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_FD) ||
+		    uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET) ||
+		    !ib_dev->ops.create_user_cq)
+			return -EINVAL;
+		desc->type = IB_UVERBS_BUFFER_TYPE_VA;
+		return 0;
+	}
+
+	if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_FD)) {
+		ret = uverbs_get_raw_fd(&desc->fd, attrs,
+					UVERBS_ATTR_CREATE_CQ_BUFFER_FD);
+		if (ret)
+			return ret;
+
+		ret = uverbs_copy_from(&desc->addr, attrs,
+				       UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET);
+		if (ret)
+			return ret;
+		ret = uverbs_copy_from(&desc->length, attrs,
+				       UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH);
+		if (ret)
+			return ret;
+		if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_VA) ||
+		    !ib_dev->ops.create_user_cq)
+			return -EINVAL;
+		desc->type = IB_UVERBS_BUFFER_TYPE_DMABUF;
+		return 0;
+	}
+
+	if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET) ||
+	    uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH))
+		return -EINVAL;
+	return -ENODATA;
+}
+
+/**
+ * ib_umem_get_cq_tmp - Temporary CQ buffer umem getter.
+ * @device: IB device.
+ * @attrs:  uverbs attribute bundle.
+ *
+ * Pins a CQ buffer described by the legacy CQ buffer attributes.
+ * Returns NULL when none are supplied.
+ *
+ * Will be removed once all CQ drivers have switched to get
+ * their buffer directly.
+ *
+ * Return: caller-owned umem on success; NULL when no legacy attribute
+ * is supplied; ERR_PTR(...) on error.
+ */
+struct ib_umem *ib_umem_get_cq_tmp(struct ib_device *device,
+				   struct uverbs_attr_bundle *attrs)
+{
+	struct ib_uverbs_buffer_desc desc = {};
+	int ret;
+
+	ret = uverbs_create_cq_get_buffer_desc(attrs, &desc);
+	if (ret == -ENODATA)
+		return NULL;
+	if (ret)
+		return ERR_PTR(ret);
+	return ib_umem_get_desc(device, &desc, IB_ACCESS_LOCAL_WRITE);
+}
+EXPORT_SYMBOL(ib_umem_get_cq_tmp);
+
 /**
  * ib_umem_release - release pinned memory
  * @umem: umem struct to release
diff --git a/drivers/infiniband/core/uverbs_std_types_cq.c b/drivers/infiniband/core/uverbs_std_types_cq.c
index 1a6bc8baa52b..711bad0aa8a3 100644
--- a/drivers/infiniband/core/uverbs_std_types_cq.c
+++ b/drivers/infiniband/core/uverbs_std_types_cq.c
@@ -66,16 +66,11 @@ static int UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE)(
 		typeof(*obj), uevent.uobject);
 	struct ib_uverbs_completion_event_file *ev_file = NULL;
 	struct ib_device *ib_dev = attrs->context->device;
-	struct ib_umem_dmabuf *umem_dmabuf;
 	struct ib_cq_init_attr attr = {};
 	struct ib_uobject *ev_file_uobj;
 	struct ib_umem *umem = NULL;
-	u64 buffer_length;
-	u64 buffer_offset;
 	struct ib_cq *cq;
 	u64 user_handle;
-	u64 buffer_va;
-	int buffer_fd;
 	int ret;
 
 	if ((!ib_dev->ops.create_cq && !ib_dev->ops.create_user_cq) ||
@@ -122,58 +117,9 @@ static int UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE)(
 	INIT_LIST_HEAD(&obj->comp_list);
 	INIT_LIST_HEAD(&obj->uevent.event_list);
 
-	if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_VA)) {
-
-		ret = uverbs_copy_from(&buffer_va, attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_VA);
-		if (ret)
-			goto err_event_file;
-
-		ret = uverbs_copy_from(&buffer_length, attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH);
-		if (ret)
-			goto err_event_file;
-
-		if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_FD) ||
-		    uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET) ||
-		    !ib_dev->ops.create_user_cq) {
-			ret = -EINVAL;
-			goto err_event_file;
-		}
-
-		umem = ib_umem_get_va(ib_dev, buffer_va, buffer_length, IB_ACCESS_LOCAL_WRITE);
-		if (IS_ERR(umem)) {
-			ret = PTR_ERR(umem);
-			goto err_event_file;
-		}
-	} else if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_FD)) {
-
-		ret = uverbs_get_raw_fd(&buffer_fd, attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_FD);
-		if (ret)
-			goto err_event_file;
-
-		ret = uverbs_copy_from(&buffer_offset, attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET);
-		if (ret)
-			goto err_event_file;
-
-		ret = uverbs_copy_from(&buffer_length, attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH);
-		if (ret)
-			goto err_event_file;
-
-		if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_VA) ||
-		    !ib_dev->ops.create_user_cq) {
-			ret = -EINVAL;
-			goto err_event_file;
-		}
-
-		umem_dmabuf = ib_umem_dmabuf_get_pinned(ib_dev, buffer_offset, buffer_length,
-							buffer_fd, IB_ACCESS_LOCAL_WRITE);
-		if (IS_ERR(umem_dmabuf)) {
-			ret = PTR_ERR(umem_dmabuf);
-			goto err_event_file;
-		}
-		umem = &umem_dmabuf->umem;
-	} else if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET) ||
-		   uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH)) {
-		ret = -EINVAL;
+	umem = ib_umem_get_cq_tmp(ib_dev, attrs);
+	if (IS_ERR(umem)) {
+		ret = PTR_ERR(umem);
 		goto err_event_file;
 	}
 
diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index fd45162eb017..afe12a1bedb0 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -92,6 +92,8 @@ struct ib_umem *ib_umem_get(struct ib_device *device, struct ib_udata *udata,
 			    u16 attr_id,
 			    ib_umem_buf_desc_filler_t legacy_filler,
 			    bool va_fallback, u64 addr, size_t size, int access);
+struct ib_umem *ib_umem_get_cq_tmp(struct ib_device *device,
+				   struct uverbs_attr_bundle *attrs);
 
 static inline struct ib_umem *ib_umem_get_va(struct ib_device *device,
 					     unsigned long addr, size_t size,
@@ -206,6 +208,11 @@ ib_umem_get(struct ib_device *device, struct ib_udata *udata, u16 attr_id,
 {
 	return ERR_PTR(-EOPNOTSUPP);
 }
+static inline struct ib_umem *
+ib_umem_get_cq_tmp(struct ib_device *device, struct uverbs_attr_bundle *attrs)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
 static inline struct ib_umem *ib_umem_get_va(struct ib_device *device,
 					     unsigned long addr, size_t size,
 					     int access)
-- 
2.53.0