2022-03-16 06:08:00

by Bob Beckett

[permalink] [raw]
Subject: [RFC PATCH 2/7] drm/i915: add ability to create memory region object in place

Signed-off-by: Robert Beckett <[email protected]>
---
drivers/gpu/drm/i915/gem/i915_gem_region.c | 55 ++++++++++++++
drivers/gpu/drm/i915/gem/i915_gem_region.h | 6 ++
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 84 ++++++++++++++++++----
drivers/gpu/drm/i915/intel_memory_region.h | 6 ++
4 files changed, 136 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.c b/drivers/gpu/drm/i915/gem/i915_gem_region.c
index c9b2e8b91053..e25ad0b9b636 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.c
@@ -98,6 +98,61 @@ i915_gem_object_create_region(struct intel_memory_region *mem,
return ERR_PTR(err);
}

+struct drm_i915_gem_object *
+i915_gem_object_create_region_in_place(struct intel_memory_region *mem,
+ resource_size_t size,
+ resource_size_t page_size,
+ unsigned int flags,
+ u64 start, u64 end)
+{
+ struct drm_i915_gem_object *obj;
+ resource_size_t default_page_size;
+ int err;
+
+ /*
+ * NB: Our use of resource_size_t for the size stems from using struct
+ * resource for the mem->region. We might need to revisit this in the
+ * future.
+ */
+
+ GEM_BUG_ON(flags & ~I915_BO_ALLOC_FLAGS);
+
+ if (!mem)
+ return ERR_PTR(-ENODEV);
+ if (!mem->ops->init_object_in_place)
+ return ERR_PTR(-EINVAL);
+
+ default_page_size = mem->min_page_size;
+ if (page_size)
+ default_page_size = page_size;
+
+ GEM_BUG_ON(!is_power_of_2_u64(default_page_size));
+ GEM_BUG_ON(default_page_size < PAGE_SIZE);
+
+ size = round_up(size, default_page_size);
+
+ GEM_BUG_ON(!size);
+ GEM_BUG_ON(!IS_ALIGNED(size, I915_GTT_MIN_ALIGNMENT));
+
+ if (i915_gem_object_size_2big(size))
+ return ERR_PTR(-E2BIG);
+
+ obj = i915_gem_object_alloc();
+ if (!obj)
+ return ERR_PTR(-ENOMEM);
+
+ err = mem->ops->init_object_in_place(mem, obj, size, page_size, flags, start, end);
+ if (err)
+ goto err_object_free;
+
+ trace_i915_gem_object_create(obj);
+ return obj;
+
+err_object_free:
+ i915_gem_object_free(obj);
+ return ERR_PTR(err);
+}
+
/**
* i915_gem_process_region - Iterate over all objects of a region using ops
* to process and optionally skip objects
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_region.h b/drivers/gpu/drm/i915/gem/i915_gem_region.h
index fcaa12d657d4..0cad90ac4a92 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_region.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_region.h
@@ -56,6 +56,12 @@ i915_gem_object_create_region(struct intel_memory_region *mem,
resource_size_t size,
resource_size_t page_size,
unsigned int flags);
+struct drm_i915_gem_object *
+i915_gem_object_create_region_in_place(struct intel_memory_region *mem,
+ resource_size_t size,
+ resource_size_t page_size,
+ unsigned int flags,
+ u64 start, u64 end);

int i915_gem_process_region(struct intel_memory_region *mr,
struct i915_gem_apply_to_region *apply);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index 45cc5837ce00..35d1bde19267 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -1131,20 +1131,12 @@ void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
}
}

-/**
- * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object
- * @mem: The initial memory region for the object.
- * @obj: The gem object.
- * @size: Object size in bytes.
- * @flags: gem object flags.
- *
- * Return: 0 on success, negative error code on failure.
- */
-int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
- struct drm_i915_gem_object *obj,
- resource_size_t size,
- resource_size_t page_size,
- unsigned int flags)
+static int __i915_gem_ttm_object_init_with_placement(struct intel_memory_region *mem,
+ struct drm_i915_gem_object *obj,
+ resource_size_t size,
+ resource_size_t page_size,
+ unsigned int flags,
+ struct ttm_placement *placement)
{
static struct lock_class_key lock_class;
struct drm_i915_private *i915 = mem->i915;
@@ -1188,7 +1180,7 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
* until successful initialization.
*/
ret = ttm_bo_init_reserved(&i915->bdev, i915_gem_to_ttm(obj), size,
- bo_type, &i915_sys_placement,
+ bo_type, placement,
page_size >> PAGE_SHIFT,
&ctx, NULL, NULL, i915_ttm_bo_destroy);
if (ret)
@@ -1204,8 +1196,70 @@ int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
return 0;
}

+/**
+ * __i915_gem_ttm_object_init - Initialize a ttm-backed i915 gem object
+ * @mem: The initial memory region for the object.
+ * @obj: The gem object.
+ * @size: Object size in bytes.
+ * @flags: gem object flags.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
+ struct drm_i915_gem_object *obj,
+ resource_size_t size,
+ resource_size_t page_size,
+ unsigned int flags)
+{
+ return __i915_gem_ttm_object_init_with_placement(mem, obj, size,
+ page_size, flags,
+ &i915_sys_placement);
+}
+
+/**
+ * i915_gem_ttm_object_init_in_place - Initialize a ttm-backed i915 gem object in place
+ * @mem: The initial memory region for the object.
+ * @obj: The gem object.
+ * @size: Object size in bytes.
+ * @page_size: Required page size.
+ * @flags: gem object flags.
+ * @start: start of range to insert in to.
+ * @end: end of range to insert in to.
+ *
+ * Initializes a ttm-backed i915 gem object with a predefined
+ * placement and range.
+ * Can be used to create an object around a pre-reserved area.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+static int i915_gem_ttm_object_init_in_place(struct intel_memory_region *mem,
+ struct drm_i915_gem_object *obj,
+ resource_size_t size,
+ resource_size_t page_size,
+ unsigned int flags,
+ u64 start,
+ u64 end)
+{
+ struct ttm_place place;
+ struct ttm_placement placement = {
+ .num_placement = 1,
+ .placement = &place,
+ .num_busy_placement = 1,
+ .busy_placement = &place,
+ };
+
+ i915_ttm_place_from_region(mem, &place, flags);
+ place.fpfn = PFN_DOWN(start);
+ place.lpfn = PFN_UP(end);
+
+ return __i915_gem_ttm_object_init_with_placement(mem, obj, size,
+ page_size, flags,
+ &placement);
+}
+
static const struct intel_memory_region_ops ttm_system_region_ops = {
.init_object = __i915_gem_ttm_object_init,
+ .init_object_in_place = i915_gem_ttm_object_init_in_place,
.release = intel_region_ttm_fini,
};

diff --git a/drivers/gpu/drm/i915/intel_memory_region.h b/drivers/gpu/drm/i915/intel_memory_region.h
index 21dcbd620758..eb72997df8f7 100644
--- a/drivers/gpu/drm/i915/intel_memory_region.h
+++ b/drivers/gpu/drm/i915/intel_memory_region.h
@@ -57,6 +57,12 @@ struct intel_memory_region_ops {
resource_size_t size,
resource_size_t page_size,
unsigned int flags);
+ int (*init_object_in_place)(struct intel_memory_region *mem,
+ struct drm_i915_gem_object *obj,
+ resource_size_t size,
+ resource_size_t page_size,
+ unsigned int flags,
+ u64 start, u64 end);
};

struct intel_memory_region {
--
2.25.1