Re: [Intel-gfx] [PATCH 08/28] drm/i915: Create a full object for mock_ring, v2.

Matthew Auld
2021-10-21T15:58:22Z

On Thu, 21 Oct 2021 at 11:36, Maarten Lankhorst
<maarten.lankhorst@linux.intel.com> wrote:
>
> This allows us to finally get rid of all the assumptions that vma->obj is NULL.
>
> Changes since v1:
> - Ensure the mock_ring vma is pinned to prevent a fault.
> - Pin it high to avoid failure in evict_for_vma selftest.
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> ---
> drivers/gpu/drm/i915/gt/mock_engine.c | 38 ++++++++++++++++++++-------
> 1 file changed, 28 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/mock_engine.c b/drivers/gpu/drm/i915/gt/mock_engine.c
> index 8b89215afe46..bb99fc03f503 100644
> --- a/drivers/gpu/drm/i915/gt/mock_engine.c
> +++ b/drivers/gpu/drm/i915/gt/mock_engine.c
> @@ -35,9 +35,31 @@ static void mock_timeline_unpin(struct intel_timeline *tl)
> atomic_dec(&tl->pin_count);
> }
>
> +static struct i915_vma *create_ring_vma(struct i915_ggtt *ggtt, int size)
> +{
> + struct i915_address_space *vm = &ggtt->vm;
> + struct drm_i915_private *i915 = vm->i915;
> + struct drm_i915_gem_object *obj;
> + struct i915_vma *vma;
> +
> + obj = i915_gem_object_create_internal(i915, size);
> + if (IS_ERR(obj))
> + return ERR_CAST(obj);

We didn't want to use the dummy object here also? I guess meh?

> +
> + vma = i915_vma_instance(obj, vm, NULL);
> + if (IS_ERR(vma))
> + goto err;
> +
> + return vma;
> +
> +err:
> + i915_gem_object_put(obj);
> + return vma;
> +}
> +
> static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
> {
> - const unsigned long sz = PAGE_SIZE / 2;
> + const unsigned long sz = PAGE_SIZE;

Is that significant?

Reviewed-by: Matthew Auld <matthew.auld@intel.com>

> struct intel_ring *ring;
>
> ring = kzalloc(sizeof(*ring) + sz, GFP_KERNEL);
> @@ -50,15 +72,11 @@ static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
> ring->vaddr = (void *)(ring + 1);
> atomic_set(&ring->pin_count, 1);
>
> - ring->vma = i915_vma_alloc();
> - if (!ring->vma) {
> + ring->vma = create_ring_vma(engine->gt->ggtt, PAGE_SIZE);
> + if (IS_ERR(ring->vma)) {
> kfree(ring);
> return NULL;
> }
> - i915_active_init(&ring->vma->active, NULL, NULL, 0);
> - __set_bit(I915_VMA_GGTT_BIT, __i915_vma_flags(ring->vma));
> - __set_bit(DRM_MM_NODE_ALLOCATED_BIT, &ring->vma->node.flags);
> - ring->vma->node.size = sz;
>
> intel_ring_update_space(ring);
>
> @@ -67,8 +85,7 @@ static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
>
> static void mock_ring_free(struct intel_ring *ring)
> {
> - i915_active_fini(&ring->vma->active);
> - i915_vma_free(ring->vma);
> + i915_vma_put(ring->vma);
>
> kfree(ring);
> }
> @@ -125,6 +142,7 @@ static void mock_context_unpin(struct intel_context *ce)
>
> static void mock_context_post_unpin(struct intel_context *ce)
> {
> + i915_vma_unpin(ce->ring->vma);
> }
>
> static void mock_context_destroy(struct kref *ref)
> @@ -169,7 +187,7 @@ static int mock_context_alloc(struct intel_context *ce)
> static int mock_context_pre_pin(struct intel_context *ce,
> struct i915_gem_ww_ctx *ww, void **unused)
> {
> - return 0;
> + return i915_vma_pin_ww(ce->ring->vma, ww, 0, 0, PIN_GLOBAL | PIN_HIGH);
> }
>
> static int mock_context_pin(struct intel_context *ce, void *unused)
> --
> 2.33.0
>