Re: [PATCH] drm/i915: Add relocation exceptions for two other platforms

[David Airlie <airlied@redhat.com>]

On Wed, Jun 2, 2021 at 12:25 AM Zbigniew Kempczyński
<zbigniew.kempczynski@intel.com> wrote:
>
> We have established previously we stop using relocations starting
> from gen12 platforms with Tigerlake as an exception. We keep this
> statement but we want to enable relocations conditionally for
> Rocketlake and Alderlake under require_force_probe flag set.
>
> Keeping relocations under require_force_probe flag is interim solution
> until IGTs will be rewritten to use softpin.
>
> v2: - remove inline from function definition (Jani)
>     - fix indentation
>
> Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
> Cc: Dave Airlie <airlied@redhat.com>
> Cc: Daniel Vetter <daniel.vetter@intel.com>
> Cc: Jason Ekstrand <jason@jlekstrand.net>

Acked-by: Dave Airlie <airlied@redhat.com>
> ---
>  .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 24 +++++++++++++++----
>  1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index 297143511f99..78b86a7bc39a 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -491,16 +491,30 @@ eb_unreserve_vma(struct eb_vma *ev)
>         ev->flags &= ~__EXEC_OBJECT_RESERVED;
>  }
>
> +static bool platform_has_relocs_enabled(const struct i915_execbuffer *eb)
> +{
> +       /*
> +        * Relocations are disallowed starting from gen12 with Tigerlake
> +        * as an exception. We allow temporarily use relocations for Rocketlake
> +        * and Alderlake when require_force_probe flag is set.
> +        */
> +       if (INTEL_GEN(eb->i915) < 12 || IS_TIGERLAKE(eb->i915))
> +               return true;
> +
> +       if (INTEL_INFO(eb->i915)->require_force_probe &&
> +           (IS_ROCKETLAKE(eb->i915) || IS_ALDERLAKE_S(eb->i915) ||
> +            IS_ALDERLAKE_P(eb->i915)))
> +               return true;
> +
> +       return false;
> +}
> +
>  static int
>  eb_validate_vma(struct i915_execbuffer *eb,
>                 struct drm_i915_gem_exec_object2 *entry,
>                 struct i915_vma *vma)
>  {
> -       /* Relocations are disallowed for all platforms after TGL-LP.  This
> -        * also covers all platforms with local memory.
> -        */
> -       if (entry->relocation_count &&
> -           INTEL_GEN(eb->i915) >= 12 && !IS_TIGERLAKE(eb->i915))
> +       if (entry->relocation_count && !platform_has_relocs_enabled(eb))
>                 return -EINVAL;
>
>         if (unlikely(entry->flags & eb->invalid_flags))
> --
> 2.26.0
>