mana: some code refactoring and export apis for future RDMA driver

• Record the physical address for doorbell page region For supporting RDMA device with multiple user contexts with their individual doorbell pages, record the start address of doorbell page region for use by the RDMA driver to allocate user context doorbell IDs.

• Handle vport sharing between devices For outgoing packets, the PF requires the VF to configure the vport with corresponding protection domain and doorbell ID for the kernel or user context. The vport can't be shared between different contexts.
  
  Implement the logic to exclusively take over the vport by either the Ethernet device or RDMA device.

• Add functions for allocating doorbell page from GDMA The RDMA device needs to allocate doorbell pages for each user context. Implement those functions and expose them for use by the RDMA driver.

• Export Work Queue functions for use by RDMA driver RDMA device may need to create Ethernet device queues for use by Queue Pair type RAW. This allows a user-mode context accesses Ethernet hardware queues. Export the supporting functions for use by the RDMA driver.

• Define max values for SGL entries The number of maximum SGl entries should be computed from the maximum WQE size for the intended queue type and the corresponding OOB data size. This guarantees the hardware queue can successfully queue requests up to the queue depth exposed to the upper layer.

• Define and process GDMA response code GDMA_STATUS_MORE_ENTRIES When doing memory registration, the PF may respond with GDMA_STATUS_MORE_ENTRIES to indicate a follow request is needed. This is not an error and should be processed as expected.

• Define data structures for protection domain and memory registration The MANA hardware support protection domain and memory registration for use in RDMA environment. Add those definitions and expose them for use by the RDMA driver.

MFC after: 2 weeks
Sponsored by: Microsoft