drivers/gpu/drm/i915/gem/selftests/huge_pages.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/i915/gem/selftests/huge_pages.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/i915/gem/selftests/huge_pages.c
Extension
.c
Size
45863 bytes
Lines
2026
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!rem) {
				sg_mark_end(sg);
				break;
			}

			sg = __sg_next(sg);
		} while ((rem - ((page_size-1) & page_mask)) >= page_size);

		page_mask &= (page_size-1);
	} while (page_mask);

	if (i915_gem_gtt_prepare_pages(obj, st))
		goto err;

	GEM_BUG_ON(sg_page_sizes != obj->mm.page_mask);
	__i915_gem_object_set_pages(obj, st);

	return 0;

err:
	sg_set_page(sg, NULL, 0, 0);
	sg_mark_end(sg);
	huge_pages_free_pages(st);

	return -ENOMEM;
}

static void put_huge_pages(struct drm_i915_gem_object *obj,
			   struct sg_table *pages)
{
	i915_gem_gtt_finish_pages(obj, pages);
	huge_pages_free_pages(pages);

	obj->mm.dirty = false;

	__start_cpu_write(obj);
}

static const struct drm_i915_gem_object_ops huge_page_ops = {
	.name = "huge-gem",
	.flags = I915_GEM_OBJECT_IS_SHRINKABLE,
	.get_pages = get_huge_pages,
	.put_pages = put_huge_pages,
};

static struct drm_i915_gem_object *
huge_pages_object(struct drm_i915_private *i915,
		  u64 size,
		  unsigned int page_mask)
{
	static struct lock_class_key lock_class;
	struct drm_i915_gem_object *obj;
	unsigned int cache_level;

	GEM_BUG_ON(!size);
	GEM_BUG_ON(!IS_ALIGNED(size, BIT(__ffs(page_mask))));

	if (size >> PAGE_SHIFT > INT_MAX)
		return ERR_PTR(-E2BIG);

	if (overflows_type(size, obj->base.size))
		return ERR_PTR(-E2BIG);

	obj = i915_gem_object_alloc();
	if (!obj)
		return ERR_PTR(-ENOMEM);

	drm_gem_private_object_init(&i915->drm, &obj->base, size);
	i915_gem_object_init(obj, &huge_page_ops, &lock_class, 0);
	obj->mem_flags |= I915_BO_FLAG_STRUCT_PAGE;
	i915_gem_object_set_volatile(obj);

	obj->write_domain = I915_GEM_DOMAIN_CPU;
	obj->read_domains = I915_GEM_DOMAIN_CPU;

	cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
	i915_gem_object_set_cache_coherency(obj, cache_level);

	obj->mm.page_mask = page_mask;

	return obj;
}

static int fake_get_huge_pages(struct drm_i915_gem_object *obj)
{
	struct drm_i915_private *i915 = to_i915(obj->base.dev);
	const u64 max_len = rounddown_pow_of_two(UINT_MAX);
	struct sg_table *st;
	struct scatterlist *sg;
	u64 rem;

Annotation

Implementation Notes