[igt-dev] [PATCH i-g-t 2/2] lib/i915/gem_mman: mmap to the CPU instead of the GTT in some tests

[Chris Wilson]

Quoting Stuart Summers (2019-11-19 18:16:19)
> Do not limit to the GTT for tests which are not specifically testing
> capability in the GTT.
> 
> Signed-off-by: Stuart Summers <stuart.summers at intel.com>
> ---
>  lib/i915/gem_mman.c            | 19 +++++++++++++++++++
>  lib/i915/gem_mman.h            |  1 +
>  tests/i915/gem_ctx_shared.c    | 20 +++++---------------
>  tests/i915/gem_exec_schedule.c |  3 +--
>  4 files changed, 26 insertions(+), 17 deletions(-)
> 
> diff --git a/lib/i915/gem_mman.c b/lib/i915/gem_mman.c
> index a0e34aef..d37840f7 100644
> --- a/lib/i915/gem_mman.c
> +++ b/lib/i915/gem_mman.c
> @@ -40,6 +40,25 @@
>  #define VG(x) do {} while (0)
>  #endif
>  
> +void *gem_mmap_host(int fd, uint32_t handle, uint64_t size, unsigned prot)
> +{
> +       void *ptr;
> +       uint32_t domain;
> +
> +       if (gem_has_mappable_ggtt(fd)) {
> +               ptr = gem_mmap__gtt(fd, handle, size, prot);
> +               domain = I915_GEM_DOMAIN_GTT;
> +       } else {
> +               ptr = gem_mmap__cpu(fd, handle, 0, size, prot);
> +               domain = I915_GEM_DOMAIN_CPU;
> +       }
> +
> +       gem_set_domain(fd, handle, /* no write hazard lies! */
> +                      domain, domain);

And be very careful putting the set-domain in here; as the lies are
integral to the test and not suitable for libraries. Domain handling is
sadly of paramount importance for most tests.
-Chris