[igt-dev] [PATCH i-g-t 7/9] tests/i915_pm_rpm: use device coherent mapping instead of mmap_gtt

[Dixit, Ashutosh]

On Fri, 31 Jan 2020 09:31:07 -0800, Ramalingam C wrote:
>
> Since on new discrete GPUs we dont have the mappable aperture, if that
> is acceptable for the test purpose, we should use GEM_MMAP_OFFSET.
> Hence using gem_mmap_device_coherent() which wraps the mmap options in
> the order of gem_mmap_offset / gem_mmap / mmap_gtt
>
> Incase of fencing/gtt related tests, we mandate the existance of the
> mmap_gtt.
>
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> ---
>  tests/i915/i915_pm_rpm.c | 24 +++++++++++++++---------
>  1 file changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/tests/i915/i915_pm_rpm.c b/tests/i915/i915_pm_rpm.c
> index f5f813c3d952..9524d7d3a4dd 100644
> --- a/tests/i915/i915_pm_rpm.c
> +++ b/tests/i915/i915_pm_rpm.c
> @@ -1392,8 +1392,8 @@ static void gem_evict_pwrite_subtest(void)
>
>	for (n = 0; n < num_trash_bos; n++) {
>		trash_bos[n].handle = gem_create(drm_fd, 1024*1024);
> -		trash_bos[n].ptr = gem_mmap__gtt(drm_fd, trash_bos[n].handle,
> -						 1024*1024, PROT_WRITE);
> +		trash_bos[n].ptr = gem_mmap__device_coherent(drm_fd, trash_bos[n].handle,
> +							     0, 1024*1024, PROT_WRITE);
>		*trash_bos[n].ptr = 0;
>	}

What does gem_mappable_aperture_size() just above return when we don't have
a mappable aperture? Maybe this also needs to be skipped instead?

> @@ -1535,7 +1535,7 @@ static void fill_igt_fb(struct igt_fb *fb, uint32_t color)
>	int i;
>	uint32_t *ptr;
>
> -	ptr = gem_mmap__gtt(drm_fd, fb->gem_handle, fb->size, PROT_WRITE);
> +	ptr = gem_mmap__device_coherent(drm_fd, fb->gem_handle, 0, fb->size, PROT_WRITE);
>	for (i = 0; i < fb->size/sizeof(uint32_t); i++)
>		ptr[i] = color;
>	igt_assert(munmap(ptr, fb->size) == 0);

Even though fill_igt_fb() is called with tiling set, I think it is still ok
to do this since all we are doing is filling a solid color for which tiling
is immaterial.

> @@ -1827,8 +1827,8 @@ static void pm_test_tiling(void)
>		for (j = 0, k = 1 << off_bit;
>		     k <= gtt_obj_max_size; k <<= 1, j++) {
>			handles[j] = gem_create(drm_fd, k);
> -			gem_bufs[j] = gem_mmap__gtt(drm_fd, handles[j],
> -						    k, PROT_WRITE);
> +			gem_bufs[j] = gem_mmap__device_coherent(drm_fd, handles[j],
> +								0, k, PROT_WRITE);
>			memset(gem_bufs[j], 0x0, k);
>		}

Maybe we should skip this instead because set/get tiling calls below will
fail/assert?

> @@ -1872,7 +1872,7 @@ static void pm_test_caching(void)
>
>	handle = gem_create(drm_fd, gtt_obj_max_size);
>	default_cache_level = gem_get_caching(drm_fd, handle);
> -	gem_buf = gem_mmap__gtt(drm_fd, handle, gtt_obj_max_size, PROT_WRITE);
> +	gem_buf = gem_mmap__device_coherent(drm_fd, handle, 0, gtt_obj_max_size, PROT_WRITE);
>
>	for (i = 0; i < ARRAY_SIZE(cache_levels); i++) {
>		igt_assert(wait_for_suspended());

Does the test work ok or assert with this change? Also I am not sure but
from the comments it seems the purpose of the test is to really do with
GGTT so it should be skipped when we don't have aperture?

> @@ -2016,8 +2016,10 @@ igt_main_args("", long_options, help_str, opt_handler, NULL)
>	/* GEM */
>	igt_subtest("gem-mmap-cpu")
>		gem_mmap_subtest(false);
> -	igt_subtest("gem-mmap-gtt")
> +	igt_subtest("gem-mmap-gtt") {
> +		gem_require_mappable_ggtt(drm_fd);
>		gem_mmap_subtest(true);
> +	}
>	igt_subtest("gem-pread")
>		gem_pread_subtest();
>	igt_subtest("gem-execbuf")
> @@ -2058,10 +2060,14 @@ igt_main_args("", long_options, help_str, opt_handler, NULL)
>		dpms_mode_unset_subtest(SCREEN_TYPE_LPSP);
>	igt_subtest("dpms-mode-unset-non-lpsp")
>		dpms_mode_unset_subtest(SCREEN_TYPE_NON_LPSP);
> -	igt_subtest("fences")
> +	igt_subtest("fences") {
> +		gem_require_mappable_ggtt(drm_fd);
>		fences_subtest(false);
> -	igt_subtest("fences-dpms")
> +	}
> +	igt_subtest("fences-dpms") {
> +		gem_require_mappable_ggtt(drm_fd);
>		fences_subtest(true);
> +	}

These skips look ok to me.