HighPoint RocketRAID hptiop

Controller register map

`hptiop`는 HighPoint RocketRAID 3xxx/4xxx adapter의 IOP와 PCI BAR를 통해 통신한다. RR44xx Intel IOP adapter는 BAR0의 link interrupt register와 BAR2의 message, doorbell, interrupt, queue port를 사용한다.

일반 Intel IOP adapter에서는 같은 message·doorbell·interrupt·queue register 집합이 모두 PCI BAR0의 `0x10`부터 `0x44` 사이에 배치된다.

Frey가 아닌 Marvell IOP adapter는 BAR0에 doorbell과 interrupt mask를, BAR1에 queue pointer·message register·inbound/outbound queue memory를 둔다.

Marvell Frey IOP adapter의 BAR0 offset `0x0`은 IOP configuration information이다. BAR1에는 inbound/outbound list의 base address와 pointer, interrupt register, PCIe Function 0 message와 doorbell register가 배치된다.

.. SPDX-License-Identifier: GPL-2.0
.. include:: <isonum.txt>

======================================================
Highpoint RocketRAID 3xxx/4xxx Adapter Driver (hptiop)
======================================================

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

For RR44xx Intel IOP based adapters, the controller IOP is accessed via PCI BAR0 and BAR2

     ============== ==================================
     BAR0 offset    Register
     ============== ==================================
            0x11C5C Link Interface IRQ Set
            0x11C60 Link Interface IRQ Clear
     ============== ==================================

     ============== ==================================
     BAR2 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 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 not Frey 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
     ============== ==================================

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

     ============== ==================================
     BAR0 offset    Register
     ============== ==================================
             0x0    IOP configuration information.
     ============== ==================================

     ============== ===================================================
     BAR1 offset    Register
     ============== ===================================================
          0x4000    Inbound List Base Address Low
          0x4004    Inbound List Base Address High
          0x4018    Inbound List Write Pointer
          0x402C    Inbound List Configuration and Control
          0x4050    Outbound List Base Address Low
          0x4054    Outbound List Base Address High
          0x4058    Outbound List Copy Pointer Shadow Base Address Low
          0x405C    Outbound List Copy Pointer Shadow Base Address High
          0x4088    Outbound List Interrupt Cause
          0x408C    Outbound List Interrupt Enable
         0x1020C    PCIe Function 0 Interrupt Enable
         0x10400    PCIe Function 0 to CPU Message A
         0x10420    CPU to PCIe Function 0 Message A
         0x10480    CPU to PCIe Function 0 Doorbell
         0x10484    CPU to PCIe Function 0 Doorbell Enable
     ============== ===================================================

Non-Frey request queue workflow

Marvell Frey가 아닌 controller의 queued request는 inbound/outbound queue port로 처리하며 request packet은 IOP memory 또는 host memory에 둘 수 있다. Inbound queue port를 읽어 IOP BAR0 기준 offset의 빈 packet을 얻거나, host DMA coherent memory에 32-byte 정렬된 request를 할당한다.

Packet을 채운 뒤 IOP memory request는 offset을 inbound queue port에 쓰고, host memory request는 `0x80000000|(bus_addr>>5)`를 쓴다. IOP가 작업을 끝내면 같은 표현을 outbound queue에 게시하고 outbound interrupt를 발생시킨다. `IOP_REQUEST_FLAG_OUTPUT_CONTEXT`가 설정된 host request는 대신 하위 32-bit context를 게시한다.

Host는 outbound queue를 읽어 request를 완료한다. IOP memory에서 할당된 request는 outbound queue에 다시 써서 해제한다. Reset이나 flush 같은 non-queued request는 Inbound Message Register 0으로 보내며, 같은 값을 가진 outbound message가 완료를 뜻한다.

I/O Request Workflow of Not Marvell Frey
----------------------------------------

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.

Marvell Frey list workflow

Marvell Frey controller의 queued request는 inbound/outbound list로 처리한다. Host DMA coherent memory에 32-byte 정렬 request를 할당하고 request flag에 request index를 기록한다. 빈 inbound list unit에는 physical address와 request size를 넣는다.

Inbound list write pointer는 직전 unit의 index로 설정하며 지원 request 수의 끝에 닿으면 0으로 되돌린다. Pointer를 IOP에 게시하면 IOP가 request를 처리한다. 완료 시 request flag와 `IOPMU_QUEUE_MASK_HOST_BITS`를 OR한 값을 빈 outbound unit에 쓰고, 그 unit index를 copy pointer shadow register에 기록한 뒤 interrupt를 발생시킨다.

Host는 outbound list copy pointer shadow와 저장한 read pointer `N`을 비교한다. 값이 다르면 `(N+1)`번째 outbound unit에서 request index를 얻어 완료한다. Reset communication, reset, flush 같은 non-queued request는 `PCIe Function 0 to CPU Message A`로 보내며 같은 값을 가진 `CPU to PCIe Function 0 Message`가 완료를 나타낸다.

I/O Request Workflow of Marvell Frey
------------------------------------

All queued requests are handled via inbound/outbound list.

To send a request to the controller:

    - Allocate a free request in host DMA coherent memory.

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

    - Fill the request with index of the request in the flag.

      Fill a free inbound list unit with the physical address and the size of
      the request.

      Set up the inbound list write pointer with the index of previous unit,
      round to 0 if the index reaches the supported count of requests.

    - Post the inbound list writer pointer to IOP.

    - The IOP process the request. When the request is completed, the flag of
      the request with or-ed IOPMU_QUEUE_MASK_HOST_BITS will be put into a
      free outbound list unit and the index of the outbound list unit will be
      put into the copy pointer shadow register. An outbound interrupt will be
      generated.

    - The host read the outbound list copy pointer shadow register and compare
      with previous saved read pointer N. If they are different, the host will
      read the (N+1)th outbound list unit.

      The host get the index of the request from the (N+1)th outbound list
      unit and complete the request.

Non-queued requests (reset communication/reset/flush etc) can be sent via PCIe
Function 0 to CPU Message A register. The CPU to PCIe Function 0 Message register
with the same value indicates the completion of message.

User-level sysfs interface

Driver는 읽기 전용 sysfs attribute 두 개를 노출한다. `driver-version`은 driver version 문자열을, `firmware-version`은 firmware version 문자열을 반환한다.

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
     ==================   ===    ========================

License, warranty와 연락처

Copyright는 2006-2012 HighPoint Technologies, Inc.에 있다. 이 파일은 유용하리라는 기대 아래 배포되지만 상품성이나 특정 목적 적합성을 포함한 어떠한 보증도 제공하지 않으며, 자세한 조건은 GNU General Public License를 따른다.

연락처는 `[email protected]`, 웹 사이트는 `http://www.highpoint-tech.com`이다.

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