linux-sg2042/Documentation/scsi/hptiop.txt

HIGHPOINT ROCKETRAID 3xxx/4xxx ADAPTER DRIVER (hptiop)

Controller Register Map
-------------------------

For Intel IOP based adapters, the controller IOP is accessed via PCI BAR0:

     BAR0 offset    Register
            0x10    Inbound Message Register 0
            0x14    Inbound Message Register 1
            0x18    Outbound Message Register 0
            0x1C    Outbound Message Register 1
            0x20    Inbound Doorbell Register
            0x24    Inbound Interrupt Status Register
            0x28    Inbound Interrupt Mask Register
            0x30    Outbound Interrupt Status Register
            0x34    Outbound Interrupt Mask Register
            0x40    Inbound Queue Port
            0x44    Outbound Queue Port

For Marvell IOP based adapters, the IOP is accessed via PCI BAR0 and BAR1:

     BAR0 offset    Register
         0x20400    Inbound Doorbell Register
         0x20404    Inbound Interrupt Mask Register
         0x20408    Outbound Doorbell Register
         0x2040C    Outbound Interrupt Mask Register

     BAR1 offset    Register
             0x0    Inbound Queue Head Pointer
             0x4    Inbound Queue Tail Pointer
             0x8    Outbound Queue Head Pointer
             0xC    Outbound Queue Tail Pointer
            0x10    Inbound Message Register
            0x14    Outbound Message Register
     0x40-0x1040    Inbound Queue
   0x1040-0x2040    Outbound Queue


I/O Request Workflow
----------------------

All queued requests are handled via inbound/outbound queue port.
A request packet can be allocated in either IOP or host memory.

To send a request to the controller:

    - Get a free request packet by reading the inbound queue port or
      allocate a free request in host DMA coherent memory.

      The value returned from the inbound queue port is an offset
      relative to the IOP BAR0.

      Requests allocated in host memory must be aligned on 32-bytes boundary.

    - Fill the packet.

    - Post the packet to IOP by writing it to inbound queue. For requests
      allocated in IOP memory, write the offset to inbound queue port. For
      requests allocated in host memory, write (0x80000000|(bus_addr>>5))
      to the inbound queue port.

    - The IOP process the request. When the request is completed, it
      will be put into outbound queue. An outbound interrupt will be
      generated.

      For requests allocated in IOP memory, the request offset is posted to
      outbound queue.

      For requests allocated in host memory, (0x80000000|(bus_addr>>5))
      is posted to the outbound queue. If IOP_REQUEST_FLAG_OUTPUT_CONTEXT
      flag is set in the request, the low 32-bit context value will be
      posted instead.

    - The host read the outbound queue and complete the request.

      For requests allocated in IOP memory, the host driver free the request
      by writing it to the outbound queue.

Non-queued requests (reset/flush etc) can be sent via inbound message
register 0. An outbound message with the same value indicates the completion
of an inbound message.


User-level Interface
---------------------

The driver exposes following sysfs attributes:

     NAME                 R/W    Description
     driver-version        R     driver version string
     firmware-version      R     firmware version string


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