svn commit: r291263 - head/sys/dev/ntb/ntb_hw

[Conrad Meyer]

On Tue, Nov 24, 2015 at 10:51 AM, Conrad E. Meyer <cem at freebsd.org> wrote:
> Author: cem
> Date: Tue Nov 24 18:51:17 2015
> New Revision: 291263
> URL: https://svnweb.freebsd.org/changeset/base/291263
>
> Log:
>   ntb: Add MW tunable for MMR Xeon errata workaround
>
>   Adds a new tunable, ntb.hw.b2b_mw_idx, which specifies the offset (from the
>   total number of memory windows) to use for register access on hardware with
>   the SDOORBELL_LOCKUP errata.  The default is -1, i.e., the last memory
>   window.

Ah, and I forgot to add:

Non-negative 'b2b_mw_idx' values index the memory windows in the usual
order (0 is the first window, 1 is the second, etc).

Best,
Conrad