octeon_ep: remove atomic variable usage in Tx data path

Replace atomic variable "instr_pending" which represents number of
posted tx instructions pending completion, with host_write_idx and
flush_index variables in the xmit and completion processing respectively.

Signed-off-by: Shinas Rasheed <srasheed@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

octeon_ep: fix tx dma unmap len values in SG

Lengths of SG pointers are kept in the following order in
the SG entries in hardware.
63 48|47 32|31 16|15 0
-----------------------------------------
| Len 0 | Len 1 | Len 2 | Len 3 |
-----------------------------------------
| Ptr 0 |
-----------------------------------------
| Ptr 1 |
-----------------------------------------
| Ptr 2 |
-----------------------------------------
| Ptr 3 |
-----------------------------------------
Dma pointers have to be unmapped based on their
respective lengths given in this format.

Fixes: 37d79d059606 ("octeon_ep: add Tx/Rx processing and interrupt support")
Signed-off-by: Shinas Rasheed <srasheed@marvell.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

octeon_ep: delete unnecessary NULL check

vfree(NULL) is safe. NULL check before vfree() is not needed.
Delete them to simplify the code.

Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

octeon_ep: add Tx/Rx processing and interrupt support

Add support to enable MSI-x and register interrupts.
Add support to process Tx and Rx traffic. Includes processing
Tx completions and Rx refill.

Signed-off-by: Veerasenareddy Burru <vburru@marvell.com>
Signed-off-by: Abhijit Ayarekar <aayarekar@marvell.com>
Signed-off-by: Satananda Burla <sburla@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

octeon_ep: add Tx/Rx ring resource setup and cleanup

Implement Tx/Rx ring resource allocation and cleanup.

Signed-off-by: Veerasenareddy Burru <vburru@marvell.com>
Signed-off-by: Abhijit Ayarekar <aayarekar@marvell.com>
Signed-off-by: Satananda Burla <sburla@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

octeon_ep: Add driver framework and device initialization

Add driver framework and device setup and initialization for Octeon
PCI Endpoint NIC.

Add implementation to load module, initilaize, register network device,
cleanup and unload module.

Signed-off-by: Veerasenareddy Burru <vburru@marvell.com>
Signed-off-by: Abhijit Ayarekar <aayarekar@marvell.com>
Signed-off-by: Satananda Burla <sburla@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>