dma-buf needs to support multiple outstanding prepares

Registered by Jesse Barker

As the title says, the API needs to support multiple outstanding prepares. This handles the use cases for both sub-allocation (allocating one large buffer and chunking it out at the driver level), and formats where multi-planar data lives in a single buffer.

Blueprint information

Status:
Not started
Approver:
Jesse Barker
Priority:
High
Drafter:
None
Direction:
Needs approval
Assignee:
None
Definition:
New
Series goal:
Accepted for trunk
Implementation:
Unknown
Milestone target:
milestone icon backlog

Related branches

Sprints

Whiteboard

(?)

Work Items

Dependency tree

* Blueprints in grey have been implemented.

This blueprint contains Public information 
Everyone can see this information.