Re: [Intel-gfx] [PATCH] drm/i915/gem: Fix the mman selftest

[Maarten Lankhorst <maarten.lankhorst@linux.intel.com>]

Op 26-08-2021 om 09:24 schreef Thomas Hellström:
> Using the I915_MMAP_TYPE_FIXED mmap type requires the TTM backend, so
> for that mmap type, use __i915_gem_object_create_user() instead of
> i915_gem_object_create_internal(), as we really want to tests objects
> mmap-able by user-space.
>
> This also means that the out-of-space error happens at object creation
> and returns -ENXIO rather than -ENOSPC, so fix the code up to expect
> that on out-of-offset-space errors.
>
> Finally only use I915_MMAP_TYPE_FIXED for LMEM and SMEM for now if
> testing on LMEM-capable devices. For stolen LMEM, we still take the
> same path as for integrated, as that haven't been moved over to TTM yet,
> and user-space should not be able to create out of stolen LMEM anyway.
>
> Fixes: 7961c5b60f23 ("drm/i915: Add TTM offset argument to mmap.")
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> ---
>  .../drm/i915/gem/selftests/i915_gem_mman.c    | 26 +++++++++++++++----
>  1 file changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> index b20f5621f62b..68da25e66b69 100644
> --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> @@ -581,6 +581,20 @@ static enum i915_mmap_type default_mapping(struct drm_i915_private *i915)
>  	return I915_MMAP_TYPE_GTT;
>  }
>  
> +static struct drm_i915_gem_object *
> +create_sys_or_internal(struct drm_i915_private *i915,
> +		       unsigned long size)
> +{
> +	if (HAS_LMEM(i915)) {
> +		struct intel_memory_region *sys_region =
> +			i915->mm.regions[INTEL_REGION_SMEM];
> +
> +		return __i915_gem_object_create_user(i915, size, &sys_region, 1);
> +	}
> +
> +	return i915_gem_object_create_internal(i915, size);
> +}
> +
>  static bool assert_mmap_offset(struct drm_i915_private *i915,
>  			       unsigned long size,
>  			       int expected)
> @@ -589,7 +603,7 @@ static bool assert_mmap_offset(struct drm_i915_private *i915,
>  	u64 offset;
>  	int ret;
>  
> -	obj = i915_gem_object_create_internal(i915, size);
> +	obj = create_sys_or_internal(i915, size);
>  	if (IS_ERR(obj))
>  		return expected && expected == PTR_ERR(obj);
>  
> @@ -633,6 +647,7 @@ static int igt_mmap_offset_exhaustion(void *arg)
>  	struct drm_mm_node *hole, *next;
>  	int loop, err = 0;
>  	u64 offset;
> +	int enospc = HAS_LMEM(i915) ? -ENXIO : -ENOSPC;
>  
>  	/* Disable background reaper */
>  	disable_retire_worker(i915);
> @@ -683,14 +698,14 @@ static int igt_mmap_offset_exhaustion(void *arg)
>  	}
>  
>  	/* Too large */
> -	if (!assert_mmap_offset(i915, 2 * PAGE_SIZE, -ENOSPC)) {
> +	if (!assert_mmap_offset(i915, 2 * PAGE_SIZE, enospc)) {
>  		pr_err("Unexpectedly succeeded in inserting too large object into single page hole\n");
>  		err = -EINVAL;
>  		goto out;
>  	}
>  
>  	/* Fill the hole, further allocation attempts should then fail */
> -	obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
> +	obj = create_sys_or_internal(i915, PAGE_SIZE);
>  	if (IS_ERR(obj)) {
>  		err = PTR_ERR(obj);
>  		pr_err("Unable to create object for reclaimed hole\n");
> @@ -703,7 +718,7 @@ static int igt_mmap_offset_exhaustion(void *arg)
>  		goto err_obj;
>  	}
>  
> -	if (!assert_mmap_offset(i915, PAGE_SIZE, -ENOSPC)) {
> +	if (!assert_mmap_offset(i915, PAGE_SIZE, enospc)) {
>  		pr_err("Unexpectedly succeeded in inserting object into no holes!\n");
>  		err = -EINVAL;
>  		goto err_obj;
> @@ -842,7 +857,8 @@ static bool can_mmap(struct drm_i915_gem_object *obj, enum i915_mmap_type type)
>  	struct drm_i915_private *i915 = to_i915(obj->base.dev);
>  	bool no_map;
>  
> -	if (HAS_LMEM(i915))
> +	if (HAS_LMEM(i915) && (obj->mm.region->id == INTEL_REGION_SMEM ||
> +			       obj->mm.region->id == INTEL_REGION_LMEM))

Ooh just noticed, make the whole line "if (obj->ops->mmap_offset)" instead to match i915_gem_mman.c?

Otherwise looks good.

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

>  		return type == I915_MMAP_TYPE_FIXED;
>  	else if (type == I915_MMAP_TYPE_FIXED)
>  		return false;