[Skiboot] [PATCH 2/2] phb3: Add support for CAPP DMA mode

Stewart Smith stewart at linux.vnet.ibm.com
Thu Jun 9 15:48:42 AEST 2016

Ian Munsie <imunsie at au1.ibm.com> writes:
> From: Ian Munsie <imunsie at au1.ibm.com>
> The XSL used in the Mellanox CX4 card uses a DMA mode of CAPI, which
> requires a few registers configured specially. In addition to enabling
> the mode,
> - The CAPP only owns some of the PHB read buffers, and must be
>   configured to use the correct ones, and the self-snoop configured for
>   the same ones.
> - The tve needs to be configured to allow the card to access all kernel
>   memory as it uses DMA accesses to read the scheduled process area from
>   the kernel, among other things.
> These cannot be configured unconditionally, as doing so will break
> existing CAPI devices that do not use DMA mode. This adds a new mode to
> the OPAL_PCI_SET_PHB_CAPI_MODE API to enable CAPI in DMA mode.
> Since the snoop on/off modes write to the capi snoop configuration
> register, which is configured differently in DMA mode, it uses the
> redundant bits from the apc master powerbus control register to
> determine if it should configure the register for DMA mode rather than
> requiring any more permutations of the mode parameter.
> Signed-off-by: Ian Munsie <imunsie at au1.ibm.com>
> ---
>  hw/phb3.c          | 56 ++++++++++++++++++++++++++++++++++++++++++++----------

Merged to master as of 5477148a439fda9fb55ea4a828c958fcdcc10f2e

Stewart Smith
OPAL Architect, IBM.

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