[igt-dev] [PATCH i-g-t v4 0/1] gem_ctx_isolation.c - Gen11 enabling for context isolation test

[Chris Wilson]

Quoting Dale B Stimson (2019-03-05 01:03:06)
> V4:
> 
> I have tested these changes on both SKL and ICL with no regressions
> detected.
> 
> I will note that both SKL and ICL seem to currently have (at least for
> my environment) suspend/resume issues which occur with or without these
> changes (and also for gem_exec_suspend).  Therefore, the S3/S4 tests
> were not done.
> 
> Testing on ICL shows that Gen11 requires BB_OFFSET .ignore_bits =
> 0x7 instead of 0x4.  I presume that the preferred way to do this is to
> change the existing table entry for BB_OFFSET instead of splitting it
> into separate entries for GEN8-10 and GEN11.
> 
> For those registers that are force_nonpriv for some Gen levels and
> not for others, I have chosen to show the two states as separate table
> entries to make this clear.  In particular, this applies as shown below.
> Any objections to doing it that way?
> 
> +       { "CTX_PREEMPT", NOCTX /* GEN10 */, RCS0, 0x2248 },
> +       { "CS_CHICKEN1", GEN11, RCS0, 0x2580, .masked = true },
> +       { "HDC_CHICKEN1", GEN_RANGE(10, 10), RCS0, 0x7304, .masked = true },
> +
>         /* Privileged (enabled by w/a + FORCE_TO_NONPRIV) */
> -       { "CTX_PREEMPT", NOCTX /* GEN_RANGE(9, 10) */, RCS0, 0x2248 },
> +       { "CTX_PREEMPT", NOCTX /* GEN9 */, RCS0, 0x2248 },
>         { "CS_CHICKEN1", GEN_RANGE(9, 10), RCS0, 0x2580, .masked = true },
> -       { "HDC_CHICKEN1", GEN_RANGE(9, 10), RCS0, 0x7304, .masked = true },
> +       { "HDC_CHICKEN1", GEN_RANGE(9, 9), RCS0, 0x7304, .masked = true },

Looks clear enough; a few more gen and we'll have a better picture and
maybe a better method for retrieving the register db.
-Chris