[PATCH v3 04/37] drm/i915/region: support continuous allocations

Matthew Auld
2019-08-09T22:26:10Z

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/gem/i915_gem_region.c | 10 +-
drivers/gpu/drm/i915/gem/i915_gem_region.h | 3 +-
.../drm/i915/selftests/intel_memory_region.c | 152 +++++++++++++++++-
drivers/gpu/drm/i915/selftests/mock_region.c | 5 +-
5 files changed, 166 insertions(+), 8 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 5e2fa37e9bc0..eb92243d473b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -116,6 +116,10 @@ struct drm_i915_gem_object {

I915_SELFTEST_DECLARE(struct list_head st_link);

+ unsigned long flags;
+#define I915_BO_ALLOC_CONTIGUOUS BIT(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/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c
index be126e70c90f..d9cd722b5dbf 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c
@@ -42,6 +42,9 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj)
return -ENOMEM;
}

+ if (obj->flags & I915_BO_ALLOC_CONTIGUOUS)
+ flags = I915_ALLOC_CONTIGUOUS;
+
ret = __intel_memory_region_get_pages_buddy(mem, size, flags, blocks);
if (ret)
goto err_free_sg;
@@ -98,10 +101,12 @@ i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj)
}

void i915_gem_object_init_memory_region(struct drm_i915_gem_object *obj,
- struct intel_memory_region *mem)
+ struct intel_memory_region *mem,
+ unsigned long flags)
{
INIT_LIST_HEAD(&obj->mm.blocks);
obj->mm.region= mem;
+ obj->flags = flags;

mutex_lock(&mem->obj_lock);
list_add(&obj->mm.region_link, &mem->objects);
@@ -125,6 +130,9 @@ 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);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.h b/drivers/gpu/drm/i915/gem/i915_gem_region.h
index ebddc86d78f7..f2ff6f8bff74 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.h
@@ -17,7 +17,8 @@ void i915_gem_object_put_pages_buddy(struct drm_i915_gem_object *obj,
struct sg_table *pages);

void i915_gem_object_init_memory_region(struct drm_i915_gem_object *obj,
- struct intel_memory_region *mem);
+ struct intel_memory_region *mem,
+ unsigned long flags);
void i915_gem_object_release_memory_region(struct drm_i915_gem_object *obj);

struct drm_i915_gem_object *
diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
index 2f13e4c1d999..70b467d4e811 100644
--- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
@@ -81,17 +81,17 @@ 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->mm.region_link, &obj->mm.region->purgeable);
}

-static int igt_mock_shrink(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;
@@ -109,7 +109,7 @@ static int igt_mock_shrink(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)
@@ -123,6 +123,39 @@ static int igt_mock_shrink(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_shrink(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.chunk_size;
+
while (target <= total / 2) {
obj = i915_gem_object_create_region(mem, target, 0);
if (IS_ERR(obj)) {
@@ -154,11 +187,120 @@ static int igt_mock_shrink(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.chunk_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_shrink),
+ 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 cc97250dca62..d73f37712c44 100644
--- a/drivers/gpu/drm/i915/selftests/mock_region.c
+++ b/drivers/gpu/drm/i915/selftests/mock_region.c
@@ -23,6 +23,9 @@ 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.chunk_size)
return ERR_PTR(-E2BIG);

@@ -38,7 +41,7 @@ mock_object_create(struct intel_memory_region *mem,
cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE;
i915_gem_object_set_cache_coherency(obj, cache_level);

- i915_gem_object_init_memory_region(obj, mem);
+ i915_gem_object_init_memory_region(obj, mem, flags);

return obj;
}