[Intel-gfx] [PATCH 16/16] drm/i915: Add selftests for object allocation, phys

[Tvrtko Ursulin]

On 07/12/2016 13:58, Chris Wilson wrote:
> The phys object is a rarely used device (only very old machines require
> a chunk of physically contiguous pages for a few hardware interactions).
> As such, it is not exercised by CI and to combat that we want to add a
> test that exercises the phys object on all platforms.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_gem.c            | 168 +++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_mock_selftests.h |   1 +
>  2 files changed, 169 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 9794dd655877..1ab5fdae2d47 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -4949,3 +4949,171 @@ i915_gem_object_get_dma_address(struct drm_i915_gem_object *obj,
>  	sg = i915_gem_object_get_sg(obj, n, &offset);
>  	return sg_dma_address(sg) + (offset << PAGE_SHIFT);
>  }
> +
> +#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
> +#include <linux/pm_runtime.h>
> +
> +#include "i915_selftest.h"
> +
> +static struct drm_driver mock_driver = {
> +	.name = "mock",
> +	.driver_features = DRIVER_GEM,
> +
> +	.gem_close_object = i915_gem_close_object,
> +	.gem_free_object_unlocked = i915_gem_free_object,
> +};
> +
> +struct mock_object {
> +	struct drm_i915_gem_object base;
> +};
> +
> +static void release_dev(struct device *dev)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +
> +	kfree(pdev);
> +}
> +
> +static struct drm_i915_private *mock_gem_device(void)
> +{
> +	struct drm_i915_private *i915;
> +	struct pci_dev *pdev;
> +	int err;
> +
> +	i915 = kzalloc(sizeof(*i915), GFP_TEMPORARY);
> +	if (!i915)
> +		return NULL;
> +
> +	pdev = kzalloc(sizeof(*pdev), GFP_TEMPORARY);
> +	if (!pdev) {
> +		kfree(i915);
> +		return NULL;
> +	}
> +
> +	device_initialize(&pdev->dev);
> +	pdev->dev.release = release_dev;
> +	dev_set_name(&pdev->dev, "mock");
> +	dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> +
> +	pm_runtime_dont_use_autosuspend(&pdev->dev);
> +	pm_runtime_get_sync(&pdev->dev);
> +	pci_set_drvdata(pdev, i915);
> +
> +	err = drm_dev_init(&i915->drm, &mock_driver, &pdev->dev);
> +	if (err) {
> +		pr_err("Failed to initialise mock GEM device: err=%d\n", err);
> +		put_device(&pdev->dev);
> +		kfree(i915);
> +		return NULL;
> +	}
> +	i915->drm.pdev = pdev;
> +	i915->drm.dev_private = i915;
> +
> +	mkwrite_device_info(i915)->gen = -1;
> +
> +	spin_lock_init(&i915->mm.object_stat_lock);
> +
> +	INIT_WORK(&i915->mm.free_work, __i915_gem_free_work);
> +	init_llist_head(&i915->mm.free_list);
> +
> +	i915->objects = KMEM_CACHE(mock_object, SLAB_HWCACHE_ALIGN);
> +	if (!i915->objects)
> +		goto err_device;
> +
> +	return i915;
> +
> +err_device:
> +	kfree(i915);
> +	return NULL;
> +}
> +
> +static void mock_device_free(struct drm_i915_private *i915)
> +{
> +	struct pci_dev *pdev = i915->drm.pdev;
> +
> +	rcu_barrier();
> +	while (flush_work(&i915->mm.free_work))
> +		rcu_barrier();
> +
> +	drm_dev_unref(&i915->drm);
> +	put_device(&pdev->dev);
> +}
> +
> +static int igt_gem_object(void *ignore)
> +{
> +	struct drm_i915_gem_object *obj;
> +	struct drm_i915_private *i915;
> +	int err = -ENOMEM;
> +
> +	i915 = mock_gem_device();
> +	if (!i915)
> +		goto out;
> +
> +	obj = i915_gem_object_create(i915, 4096);
> +	if (IS_ERR(obj)) {
> +		err = PTR_ERR(obj);
> +		pr_err("i915_gem_object_create failed, err=%d\n", err);
> +		goto out_device;
> +	}
> +
> +	err = 0;
> +	i915_gem_object_put(obj);
> +out_device:
> +	mock_device_free(i915);
> +out:
> +	return err;
> +}
> +
> +static int igt_phys_object(void *ignore)
> +{
> +	struct drm_i915_gem_object *obj;
> +	struct drm_i915_private *i915;
> +	int err = -ENOMEM;
> +
> +	i915 = mock_gem_device();
> +	if (!i915)
> +		goto out;
> +
> +	obj = i915_gem_object_create(i915, 4096);
> +	if (IS_ERR(obj)) {
> +		err = PTR_ERR(obj);
> +		pr_err("i915_gem_object_create failed, err=%d\n", err);
> +		goto out_device;
> +	}
> +
> +	err = -EINVAL;
> +	mutex_lock(&i915->drm.struct_mutex);
> +	err = i915_gem_object_attach_phys(obj, PAGE_SIZE);
> +	mutex_unlock(&i915->drm.struct_mutex);
> +	if (err) {
> +		pr_err("i915_gem_object_attach_phys failed, err=%d\n", err);
> +		goto err;
> +	}
> +
> +	if (obj->ops != &i915_gem_phys_ops) {
> +		pr_err("i915_gem_object_attach_phys did not create a phys object\n");
> +		goto err;
> +	}
> +
> +	/* Make the object work during teardown */

Not the clearest what does "work" mean? I see that the exercises the 
copy to shmem path, just saying comment could be better.

> +	obj->mm.dirty = true;
> +
> +	err = 0;
> +err:
> +	i915_gem_object_put(obj);
> +out_device:
> +	mock_device_free(i915);
> +out:
> +	return err;
> +}
> +
> +int i915_gem_object_selftests(void)
> +{
> +	static const struct i915_subtest tests[] = {
> +		SUBTEST(igt_gem_object),
> +		SUBTEST(igt_phys_object),
> +	};
> +
> +	return i915_subtests(tests, NULL);
> +}
> +#endif

Would it be worth shunting these "if 
IS_ENABLED(CONFIG_DRM_I915_SELFTEST)" blocks into separate files and 
include them from the parent?

Like in this case:

#include "i915_gem_selftests.c"

Or even:

#include "selftests/i915_gem.c"

If the include is at the end of the file it should always work. It will 
be more manageable as the tests grow I think.

> diff --git a/drivers/gpu/drm/i915/i915_mock_selftests.h b/drivers/gpu/drm/i915/i915_mock_selftests.h
> index 9ff379b18c20..34f32f777b34 100644
> --- a/drivers/gpu/drm/i915/i915_mock_selftests.h
> +++ b/drivers/gpu/drm/i915/i915_mock_selftests.h
> @@ -8,6 +8,7 @@
>   *
>   * Tests are executed in reverse order by igt/drv_selftest
>   */
> +selftest(objects, i915_gem_object_selftests)
>  selftest(requests, i915_gem_request_selftest)
>  selftest(breadcrumbs, intel_breadcrumbs_selftest)
>  selftest(sanitycheck, i915_mock_sanitycheck) /* keep last */
>

Looks clean enough and although I am not 100% familiar with some of the 
core APIs used - if it works it works.

Strong suggestion to consider the move to a separate file, but in essence:

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko