Re: [PATCH v10 08/22] IB/hns: Add icm support

On Tue, Jun 21, 2016 at 12:37:39PM +0800, Wei Hu (Xavier) wrote:

On 2016/6/20 21:04, Leon Romanovsky wrote:

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On Mon, Jun 20, 2016 at 05:48:15PM +0800, Wei Hu (Xavier) wrote:

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On 2016/6/20 17:27, Leon Romanovsky wrote:

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On Mon, Jun 20, 2016 at 03:49:24PM +0800, Wei Hu (Xavier) wrote:

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On 2016/6/20 14:06, Leon Romanovsky wrote:

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On Mon, Jun 20, 2016 at 12:37:40PM +0800, Wei Hu (Xavier) wrote:

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On 2016/6/17 17:58, Leon Romanovsky wrote:

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On Thu, Jun 16, 2016 at 10:35:16PM +0800, Lijun Ou wrote:

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This patch mainly added icm support for RoCE. It initializes icm
which managers the relative memory blocks for RoCE. The data
structures of RoCE will be located in it. For example, CQ table,
QP table and MTPT table so on.

Signed-off-by: Wei Hu <redacted>
Signed-off-by: Nenglong Zhao <zhaonenglong-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org>
Signed-off-by: Lijun Ou <redacted>
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+

Another question which you didn't answer [1].

"I wonder if you have the same needs for ICM as it is in mlx4 device.
Do you have firmware?"

[1] http://marc.info/?l=linux-rdma&m=146545553104913&w=2

Hi, Leon
    Now we haven't firmware.
    But hardware still need memory for QPC\CQC\MTPT\mtt etc.

ICM stands for InfiniHost (Interconnect) Context Memory is a specific
memory place to share between host <-> FW and host <-> HW if HW is
aware of specific structures.

I assume that in your case, it is enough to allocate memory region and
supply it to HW. Am I right?

For Our hardware,
1. ICM has a memory management method, It's very good for QPC\CQC\MTPT\mtt
etc. we need it.

You need special HW to leverage its. AFAIK it is Mellanox specific.

For our hardware, we use ICM to memory management, the memory shared with
host and HW.
QPC\CQC\MTPT\mtt has specific memory requirement.
QPC\CQC\MTPT need continuous memory. we use ICM to management the block of
memory. It's very good！

I wasn't convinced why do you need to copy whole ICM logic which is
specific to Mellanox. Your requirements can be implemented by standard CMA
and/or DMA.

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2. The meomry for QPC\CQC\MTPT\mtt only used for RoCE hardware and driver,
we don't want use MR.

I didn't mean Infiniband MR, but memory region returned from standard
allocation functions (kmalloc, ...).

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3. Now we haven't firmware, maybe we need it next version.

You are always invited to add support once it will be needed, no need to
add it in advance.

Thanks