[RFC PATCH 16/42] drm/i915: support basic object migration

Matthew Auld
2019-02-14T14:58:03Z

We are going want to able to move objects between different regions
like system memory and local memory. In the future everything should
be just another region.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 5 +
drivers/gpu/drm/i915/i915_gem.c | 121 +++++++++++++++++
.../drm/i915/selftests/intel_memory_region.c | 127 ++++++++++++++++++
3 files changed, 253 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b9d01caa3430..bdf85e901268 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2822,6 +2822,11 @@ i915_gem_object_create_from_data(struct drm_i915_private *dev_priv,
void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file);
void i915_gem_free_object(struct drm_gem_object *obj);

+int i915_gem_object_prepare_move(struct drm_i915_gem_object *obj);
+int i915_gem_object_migrate(struct i915_gem_context *ctx,
+ struct drm_i915_gem_object *obj,
+ enum intel_region_id id);
+
static inline void i915_gem_drain_freed_objects(struct drm_i915_private *i915)
{
if (!atomic_read(&i915->mm.free_count))
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 501714fbf92f..33699b3dc395 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4626,6 +4626,127 @@ int i915_gem_object_clear_blt(struct i915_gem_context *ctx,
return i915_gem_object_fill_blt(ctx, obj, 0);
}

+int i915_gem_object_prepare_move(struct drm_i915_gem_object *obj)
+{
+ int err;
+
+ lockdep_assert_held(&obj->base.dev->struct_mutex);
+
+ if (obj->mm.madv != I915_MADV_WILLNEED)
+ return -EINVAL;
+
+ if (i915_gem_object_needs_bit17_swizzle(obj))
+ return -EINVAL;
+
+ if (atomic_read(&obj->mm.pages_pin_count) > obj->bind_count)
+ return -EBUSY;
+
+ if (obj->pin_global)
+ return -EBUSY;
+
+ i915_gem_release_mmap(obj);
+
+ GEM_BUG_ON(obj->mm.mapping);
+ GEM_BUG_ON(obj->base.filp && mapping_mapped(obj->base.filp->f_mapping));
+
+ err = i915_gem_object_wait(obj,
+ I915_WAIT_INTERRUPTIBLE |
+ I915_WAIT_LOCKED |
+ I915_WAIT_ALL,
+ MAX_SCHEDULE_TIMEOUT);
+ if (err)
+ return err;
+
+ return i915_gem_object_unbind(obj);
+}
+
+int i915_gem_object_migrate(struct i915_gem_context *ctx,
+ struct drm_i915_gem_object *obj,
+ enum intel_region_id id)
+{
+ struct drm_i915_private *i915 = to_i915(obj->base.dev);
+ struct drm_i915_gem_object *donor;
+ struct intel_memory_region *mem;
+ int err = 0;
+
+ lockdep_assert_held(&i915->drm.struct_mutex);
+
+ GEM_BUG_ON(id >= INTEL_MEMORY_UKNOWN);
+ GEM_BUG_ON(obj->memory_region->id == id);
+ GEM_BUG_ON(obj->mm.madv != I915_MADV_WILLNEED);
+
+ mem = i915->regions[id];
+
+ donor = i915_gem_object_create_region(mem, obj->base.size, 0);
+ if (IS_ERR(donor))
+ return PTR_ERR(donor);
+
+ /* Copy backing-pages if we have to */
+ if (i915_gem_object_has_pages(obj)) {
+ struct sg_table *pages;
+
+ err = i915_gem_object_pin_pages(obj);
+ if (err)
+ goto err_put_donor;
+
+ err = i915_gem_object_copy_blt(ctx, obj, donor);
+ if (err)
+ goto err_put_donor;
+
+ i915_retire_requests(i915);
+
+ i915_gem_object_unbind(donor);
+ err = i915_gem_object_unbind(obj);
+ if (err)
+ goto err_put_donor;
+
+ mutex_lock(&obj->mm.lock);
+
+ pages = fetch_and_zero(&obj->mm.pages);
+ obj->ops->put_pages(obj, pages);
+
+ obj->mm.pages = __i915_gem_object_unset_pages(donor);
+ memcpy(&obj->mm.page_sizes, &donor->mm.page_sizes,
+ sizeof(struct i915_page_sizes));
+
+ obj->mm.get_page.sg_pos = obj->mm.pages->sgl;
+ obj->mm.get_page.sg_idx = 0;
+ __i915_gem_object_reset_page_iter(obj);
+
+ mutex_unlock(&obj->mm.lock);
+ }
+
+ if (obj->ops->release)
+ obj->ops->release(obj);
+
+ /* We need still need a little special casing for shmem */
+ if (obj->base.filp)
+ fput(fetch_and_zero(&obj->base.filp));
+ else
+ obj->base.filp = fetch_and_zero(&donor->base.filp);
+
+ obj->base.size = donor->base.size;
+ obj->memory_region = mem;
+ obj->flags = donor->flags;
+ obj->ops = donor->ops;
+
+ list_replace_init(&donor->blocks, &obj->blocks);
+
+ mutex_lock(&mem->obj_lock);
+ list_add(&obj->region_link, &mem->objects);
+ mutex_unlock(&mem->obj_lock);
+
+ GEM_BUG_ON(i915_gem_object_has_pages(donor));
+ GEM_BUG_ON(i915_gem_object_has_pinned_pages(donor));
+
+err_put_donor:
+ i915_gem_object_put(donor);
+ if (i915_gem_object_has_pinned_pages(obj))
+ i915_gem_object_unpin_pages(obj);
+
+ return err;
+}
+
static void __i915_gem_free_objects(struct drm_i915_private *i915,
struct llist_node *freed)
{
diff --git a/drivers/gpu/drm/i915/selftests/intel_memory_region.c b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
index 210ec6fec19a..2c07d8d219e5 100644
--- a/drivers/gpu/drm/i915/selftests/intel_memory_region.c
+++ b/drivers/gpu/drm/i915/selftests/intel_memory_region.c
@@ -579,6 +579,57 @@ static int igt_lmem_create(void *arg)
return err;
}

+static int igt_smem_create_migrate(void *arg)
+{
+ struct i915_gem_context *ctx = arg;
+ struct drm_i915_private *i915 = ctx->i915;
+ struct drm_i915_gem_object *obj;
+ int err = 0;
+
+ /* Switch object backing-store on create */
+ obj = i915_gem_object_create_lmem(i915, PAGE_SIZE, 0);
+ if (IS_ERR(obj))
+ return PTR_ERR(obj);
+ err = i915_gem_object_migrate(ctx, obj, INTEL_MEMORY_SMEM);
+ if (err)
+ goto out_put;
+
+ err = i915_gem_object_pin_pages(obj);
+ if (err)
+ goto out_put;
+
+ i915_gem_object_unpin_pages(obj);
+out_put:
+ i915_gem_object_put(obj);
+
+ return err;
+}
+
+static int igt_lmem_create_migrate(void *arg)
+{
+ struct i915_gem_context *ctx = arg;
+ struct drm_i915_private *i915 = ctx->i915;
+ struct drm_i915_gem_object *obj;
+ int err = 0;
+
+ /* Switch object backing-store on create */
+ obj = i915_gem_object_create(i915, PAGE_SIZE);
+ if (IS_ERR(obj))
+ return PTR_ERR(obj);
+ err = i915_gem_object_migrate(ctx, obj, INTEL_MEMORY_LMEM);
+ if (err)
+ goto out_put;
+
+ err = i915_gem_object_pin_pages(obj);
+ if (err)
+ goto out_put;
+
+ i915_gem_object_unpin_pages(obj);
+out_put:
+ i915_gem_object_put(obj);
+
+ return err;
+}
static int igt_lmem_write_gpu(void *arg)
{
struct i915_gem_context *ctx = arg;
@@ -608,6 +659,79 @@ static int igt_lmem_write_gpu(void *arg)
return err;
}

+static int igt_lmem_pages_migrate(void *arg)
+{
+ struct i915_gem_context *ctx = arg;
+ struct drm_i915_private *i915 = ctx->i915;
+ struct drm_i915_gem_object *obj;
+ int err;
+ int i;
+
+ /* From LMEM to shmem and back again */
+
+ obj = i915_gem_object_create_lmem(i915, SZ_2M, 0);
+ if (IS_ERR(obj))
+ return PTR_ERR(obj);
+
+ err = i915_gem_object_clear_blt(ctx, obj);
+ if (err)
+ goto out_put;
+
+ for (i = 1; i <= 4; ++i) {
+ err = i915_gem_object_prepare_move(obj);
+ if (err)
+ goto out_put;
+
+ if (i915_gem_object_is_lmem(obj)) {
+ err = i915_gem_object_migrate(ctx, obj, INTEL_MEMORY_SMEM);
+ if (err)
+ goto out_put;
+
+ if (i915_gem_object_is_lmem(obj)) {
+ pr_err("object still backed by lmem\n");
+ err = -EINVAL;
+ }
+
+ if (!list_empty(&obj->blocks)) {
+ pr_err("object leaking memory region\n");
+ err = -EINVAL;
+ }
+
+ if (!i915_gem_object_has_struct_page(obj)) {
+ pr_err("object not backed by struct page\n");
+ err = -EINVAL;
+ }
+
+ } else {
+ err = i915_gem_object_migrate(ctx, obj, INTEL_MEMORY_LMEM);
+ if (err)
+ goto out_put;
+
+ if (i915_gem_object_has_struct_page(obj)) {
+ pr_err("object still backed by struct page\n");
+ err = -EINVAL;
+ }
+
+ if (!i915_gem_object_is_lmem(obj)) {
+ pr_err("object not backed by lmem\n");
+ err = -EINVAL;
+ }
+ }
+
+ if (err)
+ break;
+
+ err = i915_gem_object_fill_blt(ctx, obj, 0xdeadbeaf);
+ if (err)
+ break;
+ }
+
+out_put:
+ i915_gem_object_put(obj);
+
+ return err;
+}
+
int intel_memory_region_mock_selftests(void)
{
static const struct i915_subtest tests[] = {
@@ -649,7 +773,10 @@ int intel_memory_region_live_selftests(struct drm_i915_private *i915)
{
static const struct i915_subtest tests[] = {
SUBTEST(igt_lmem_create),
+ SUBTEST(igt_smem_create_migrate),
+ SUBTEST(igt_lmem_create_migrate),
SUBTEST(igt_lmem_write_gpu),
+ SUBTEST(igt_lmem_pages_migrate),
};
struct i915_gem_context *ctx;
struct drm_file *file;
--
2.20.1