[PATCH v2 04/37] drm/i915/region: support continuous allocations

Matthew Auld
2019-06-27T20:56:41Z

Some objects may need to be allocated as a continuous block, thinking
ahead the various kernel io_mapping interfaces seem to expect it.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
---
.../gpu/drm/i915/gem/i915_gem_object_types.h | 4 +
drivers/gpu/drm/i915/intel_memory_region.c | 7 +-
.../drm/i915/selftests/intel_memory_region.c | 152 +++++++++++++++++-
drivers/gpu/drm/i915/selftests/mock_region.c | 3 +
4 files changed, 160 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index 87000fc24ab3..1c4b99e507c3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -133,6 +133,10 @@ struct drm_i915_gem_object {
struct list_head batch_pool_link;
I915_SELFTEST_DECLARE(struct list_head st_link);

+ unsigned long flags;
+#define I915_BO_ALLOC_CONTIGUOUS (1<<0)
+#define I915_BO_ALLOC_FLAGS (I915_BO_ALLOC_CONTIGUOUS)
+
/*
* Is the object to be mapped as read-only to the GPU
* Only honoured if hardware has relevant pte bit
diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c
index 721b47e46492..9b6a32bfa20d 100644
--- a/drivers/gpu/drm/i915/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/intel_memory_region.c
@@ -90,6 +90,7 @@ i915_memory_region_get_pages_buddy(struct drm_i915_gem_object *obj)
{
struct intel_memory_region *mem = obj->memory_region;
resource_size_t size = obj->base.size;
+ unsigned int flags = obj->flags;
struct sg_table *st;
struct scatterlist *sg;
unsigned int sg_page_sizes;
@@ -130,7 +131,7 @@ i915_memory_region_get_pages_buddy(struct drm_i915_gem_object *obj)
if (!IS_ERR(block))
break;

- if (!order--) {
+ if (flags & I915_BO_ALLOC_CONTIGUOUS || !order--) {
resource_size_t target;
int err;

@@ -219,6 +220,9 @@ i915_gem_object_create_region(struct intel_memory_region *mem,
if (!mem)
return ERR_PTR(-ENODEV);

+ if (flags & ~I915_BO_ALLOC_FLAGS)
+ return ERR_PTR(-EINVAL);
+
size = round_up(size, mem->min_page_size);

GEM_BUG_ON(!size);
@@ -236,6 +240,7 @@ i915_gem_object_create_region(struct intel_memory_region *mem,

INIT_LIST_HEAD(&obj->blocks);
obj->memory_region = mem;
+ obj->flags = flags;

mutex_lock(&mem->obj_lock);
list_add(&obj->region_link, &mem->objects);
diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
index ece499869747..c9de8b5039e4 100644
--- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
@@ -78,17 +78,17 @@ static int igt_mock_fill(void *arg)

static void igt_mark_evictable(struct drm_i915_gem_object *obj)
{
- i915_gem_object_unpin_pages(obj);
+ if (i915_gem_object_has_pinned_pages(obj))
+ i915_gem_object_unpin_pages(obj);
obj->mm.madv = I915_MADV_DONTNEED;
list_move(&obj->region_link, &obj->memory_region->purgeable);
}

-static int igt_mock_evict(void *arg)
+static int igt_frag_region(struct intel_memory_region *mem,
+ struct list_head *objects)
{
- struct intel_memory_region *mem = arg;
struct drm_i915_gem_object *obj;
unsigned long n_objects;
- LIST_HEAD(objects);
resource_size_t target;
resource_size_t total;
int err = 0;
@@ -104,7 +104,7 @@ static int igt_mock_evict(void *arg)
goto err_close_objects;
}

- list_add(&obj->st_link, &objects);
+ list_add(&obj->st_link, objects);

err = i915_gem_object_pin_pages(obj);
if (err)
@@ -118,6 +118,39 @@ static int igt_mock_evict(void *arg)
igt_mark_evictable(obj);
}

+ return 0;
+
+err_close_objects:
+ close_objects(objects);
+ return err;
+}
+
+static void igt_defrag_region(struct list_head *objects)
+{
+ struct drm_i915_gem_object *obj;
+
+ list_for_each_entry(obj, objects, st_link) {
+ if (obj->mm.madv == I915_MADV_WILLNEED)
+ igt_mark_evictable(obj);
+ }
+}
+
+static int igt_mock_evict(void *arg)
+{
+ struct intel_memory_region *mem = arg;
+ struct drm_i915_gem_object *obj;
+ LIST_HEAD(objects);
+ resource_size_t target;
+ resource_size_t total;
+ int err;
+
+ err = igt_frag_region(mem, &objects);
+ if (err)
+ return err;
+
+ total = resource_size(&mem->region);
+ target = mem->mm.min_size;
+
while (target <= total / 2) {
obj = i915_gem_object_create_region(mem, target, 0);
if (IS_ERR(obj)) {
@@ -148,11 +181,120 @@ static int igt_mock_evict(void *arg)
return err;
}

+static int igt_mock_continuous(void *arg)
+{
+ struct intel_memory_region *mem = arg;
+ struct drm_i915_gem_object *obj;
+ LIST_HEAD(objects);
+ resource_size_t target;
+ resource_size_t total;
+ int err;
+
+ err = igt_frag_region(mem, &objects);
+ if (err)
+ return err;
+
+ total = resource_size(&mem->region);
+ target = total / 2;
+
+ /*
+ * Sanity check that we can allocate all of the available fragmented
+ * space.
+ */
+ obj = i915_gem_object_create_region(mem, target, 0);
+ if (IS_ERR(obj)) {
+ err = PTR_ERR(obj);
+ goto err_close_objects;
+ }
+
+ list_add(&obj->st_link, &objects);
+
+ err = i915_gem_object_pin_pages(obj);
+ if (err) {
+ pr_err("failed to allocate available space\n");
+ goto err_close_objects;
+ }
+
+ igt_mark_evictable(obj);
+
+ /* Try the smallest possible size -- should succeed */
+ obj = i915_gem_object_create_region(mem, mem->mm.min_size,
+ I915_BO_ALLOC_CONTIGUOUS);
+ if (IS_ERR(obj)) {
+ err = PTR_ERR(obj);
+ goto err_close_objects;
+ }
+
+ list_add(&obj->st_link, &objects);
+
+ err = i915_gem_object_pin_pages(obj);
+ if (err) {
+ pr_err("failed to allocate smallest possible size\n");
+ goto err_close_objects;
+ }
+
+ igt_mark_evictable(obj);
+
+ if (obj->mm.pages->nents != 1) {
+ pr_err("[1]object spans multiple sg entries\n");
+ err = -EINVAL;
+ goto err_close_objects;
+ }
+
+ /*
+ * Even though there is enough free space for the allocation, we
+ * shouldn't be able to allocate it, given that it is fragmented, and
+ * non-continuous.
+ */
+ obj = i915_gem_object_create_region(mem, target, I915_BO_ALLOC_CONTIGUOUS);
+ if (IS_ERR(obj)) {
+ err = PTR_ERR(obj);
+ goto err_close_objects;
+ }
+
+ list_add(&obj->st_link, &objects);
+
+ err = i915_gem_object_pin_pages(obj);
+ if (!err) {
+ pr_err("expected allocation to fail\n");
+ err = -EINVAL;
+ goto err_close_objects;
+ }
+
+ igt_defrag_region(&objects);
+
+ /* Should now succeed */
+ obj = i915_gem_object_create_region(mem, target, I915_BO_ALLOC_CONTIGUOUS);
+ if (IS_ERR(obj)) {
+ err = PTR_ERR(obj);
+ goto err_close_objects;
+ }
+
+ list_add(&obj->st_link, &objects);
+
+ err = i915_gem_object_pin_pages(obj);
+ if (err) {
+ pr_err("failed to allocate from defraged area\n");
+ goto err_close_objects;
+ }
+
+ if (obj->mm.pages->nents != 1) {
+ pr_err("object spans multiple sg entries\n");
+ err = -EINVAL;
+ }
+
+err_close_objects:
+ close_objects(&objects);
+
+ return err;
+}
+
int intel_memory_region_mock_selftests(void)
{
static const struct i915_subtest tests[] = {
SUBTEST(igt_mock_fill),
SUBTEST(igt_mock_evict),
+ SUBTEST(igt_mock_continuous),
};
struct intel_memory_region *mem;
struct drm_i915_private *i915;
diff --git a/drivers/gpu/drm/i915/selftests/mock_region.c b/drivers/gpu/drm/i915/selftests/mock_region.c
index 80eafdc54927..9eeda8f45f38 100644
--- a/drivers/gpu/drm/i915/selftests/mock_region.c
+++ b/drivers/gpu/drm/i915/selftests/mock_region.c
@@ -20,6 +20,9 @@ mock_object_create(struct intel_memory_region *mem,
struct drm_i915_gem_object *obj;
unsigned int cache_level;

+ if (flags & I915_BO_ALLOC_CONTIGUOUS)
+ size = roundup_pow_of_two(size);
+
if (size > BIT(mem->mm.max_order) * mem->mm.min_size)
return ERR_PTR(-E2BIG);

--
2.20.1