drm/i915: add i915_gem_object_create_region_at()

Add a generic interface for allocating an object at some specific
offset, and convert stolen over. Later we will want to hook this up to
different backends.
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220315181425.576828-4-matthew.auld@intel.com

drivers/gpu/drm/i915/display/intel_plane_initial.c

@@ -3,6 +3,7 @@
  * Copyright © 2021 Intel Corporation
  */
 
+#include "gem/i915_gem_region.h"
 #include "i915_drv.h"
 #include "intel_atomic_plane.h"
 #include "intel_display.h"
@@ -69,7 +70,8 @@ initial_plane_vma(struct drm_i915_private *i915,
 	    size * 2 > i915->stolen_usable_size)
 		return NULL;
 
-	obj = i915_gem_object_create_stolen_for_preallocated(i915, base, size);
+	obj = i915_gem_object_create_region_at(i915->mm.stolen_region,
+					       base, size, 0);
 	if (IS_ERR(obj))
 		return NULL;
 

drivers/gpu/drm/i915/gem/i915_gem_create.c

@@ -123,7 +123,7 @@ __i915_gem_object_create_user_ext(struct drm_i915_private *i915, u64 size,
 	 */
 	flags = I915_BO_ALLOC_USER;
 
-	ret = mr->ops->init_object(mr, obj, size, 0, flags);
+	ret = mr->ops->init_object(mr, obj, I915_BO_INVALID_OFFSET, size, 0, flags);
 	if (ret)
 		goto object_free;
 

drivers/gpu/drm/i915/gem/i915_gem_region.c

@@ -27,8 +27,9 @@ void i915_gem_object_release_memory_region(struct drm_i915_gem_object *obj)
 	mutex_unlock(&mem->objects.lock);
 }
 
-struct drm_i915_gem_object *
-i915_gem_object_create_region(struct intel_memory_region *mem,
+static struct drm_i915_gem_object *
+__i915_gem_object_create_region(struct intel_memory_region *mem,
+				resource_size_t offset,
 				resource_size_t size,
 				resource_size_t page_size,
 				unsigned int flags)
@@ -86,7 +87,7 @@ i915_gem_object_create_region(struct intel_memory_region *mem,
 	if (default_page_size < mem->min_page_size)
 		flags |= I915_BO_ALLOC_PM_EARLY;
 
-	err = mem->ops->init_object(mem, obj, size, page_size, flags);
+	err = mem->ops->init_object(mem, obj, offset, size, page_size, flags);
 	if (err)
 		goto err_object_free;
 
@@ -98,6 +99,40 @@ i915_gem_object_create_region(struct intel_memory_region *mem,
 	return ERR_PTR(err);
 }
 
+struct drm_i915_gem_object *
+i915_gem_object_create_region(struct intel_memory_region *mem,
+			      resource_size_t size,
+			      resource_size_t page_size,
+			      unsigned int flags)
+{
+	return __i915_gem_object_create_region(mem, I915_BO_INVALID_OFFSET,
+					       size, page_size, flags);
+}
+
+struct drm_i915_gem_object *
+i915_gem_object_create_region_at(struct intel_memory_region *mem,
+				 resource_size_t offset,
+				 resource_size_t size,
+				 unsigned int flags)
+{
+	GEM_BUG_ON(offset == I915_BO_INVALID_OFFSET);
+
+	if (GEM_WARN_ON(!IS_ALIGNED(size, mem->min_page_size)) ||
+	    GEM_WARN_ON(!IS_ALIGNED(offset, mem->min_page_size)))
+		return ERR_PTR(-EINVAL);
+
+	if (range_overflows(offset, size, resource_size(&mem->region)))
+		return ERR_PTR(-EINVAL);
+
+	if (!(flags & I915_BO_ALLOC_GPU_ONLY) &&
+	    offset + size > mem->io_size &&
+	    !i915_ggtt_has_aperture(to_gt(mem->i915)->ggtt))
+		return ERR_PTR(-ENOSPC);
+
+	return __i915_gem_object_create_region(mem, offset, size, 0,
+					       flags | I915_BO_ALLOC_CONTIGUOUS);
+}
+
 /**
  * i915_gem_process_region - Iterate over all objects of a region using ops
  * to process and optionally skip objects

drivers/gpu/drm/i915/gem/i915_gem_region.h

@@ -14,6 +14,8 @@ struct sg_table;
 
 struct i915_gem_apply_to_region;
 
+#define I915_BO_INVALID_OFFSET ((resource_size_t)-1)
+
 /**
  * struct i915_gem_apply_to_region_ops - ops to use when iterating over all
  * region objects.
@@ -56,6 +58,11 @@ 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_at(struct intel_memory_region *mem,
+				 resource_size_t offset,
+				 resource_size_t size,
+				 unsigned int flags);
 
 int i915_gem_process_region(struct intel_memory_region *mr,
 			    struct i915_gem_apply_to_region *apply);

drivers/gpu/drm/i915/gem/i915_gem_shmem.c

@@ -552,6 +552,7 @@ static int __create_shmem(struct drm_i915_private *i915,
 
 static int shmem_object_init(struct intel_memory_region *mem,
 			     struct drm_i915_gem_object *obj,
+			     resource_size_t offset,
 			     resource_size_t size,
 			     resource_size_t page_size,
 			     unsigned int flags)

drivers/gpu/drm/i915/gem/i915_gem_stolen.c

@@ -681,6 +681,7 @@ static int __i915_gem_object_create_stolen(struct intel_memory_region *mem,
 
 static int _i915_gem_object_stolen_init(struct intel_memory_region *mem,
 					struct drm_i915_gem_object *obj,
+					resource_size_t offset,
 					resource_size_t size,
 					resource_size_t page_size,
 					unsigned int flags)
@@ -707,8 +708,20 @@ static int _i915_gem_object_stolen_init(struct intel_memory_region *mem,
 	if (!stolen)
 		return -ENOMEM;
 
+	if (offset != I915_BO_INVALID_OFFSET) {
+		drm_dbg(&i915->drm,
+			"creating preallocated stolen object: stolen_offset=%pa, size=%pa\n",
+			&offset, &size);
+
+		stolen->start = offset;
+		stolen->size = size;
+		mutex_lock(&i915->mm.stolen_lock);
+		ret = drm_mm_reserve_node(&i915->mm.stolen, stolen);
+		mutex_unlock(&i915->mm.stolen_lock);
+	} else {
 		ret = i915_gem_stolen_insert_node(i915, stolen, size,
 						  mem->min_page_size);
+	}
 	if (ret)
 		goto err_free;
 
@@ -882,63 +895,6 @@ i915_gem_stolen_smem_setup(struct drm_i915_private *i915, u16 type,
 	return mem;
 }
 
-struct drm_i915_gem_object *
-i915_gem_object_create_stolen_for_preallocated(struct drm_i915_private *i915,
-					       resource_size_t stolen_offset,
-					       resource_size_t size)
-{
-	struct intel_memory_region *mem = i915->mm.stolen_region;
-	struct drm_i915_gem_object *obj;
-	struct drm_mm_node *stolen;
-	int ret;
-
-	if (!drm_mm_initialized(&i915->mm.stolen))
-		return ERR_PTR(-ENODEV);
-
-	drm_dbg(&i915->drm,
-		"creating preallocated stolen object: stolen_offset=%pa, size=%pa\n",
-		&stolen_offset, &size);
-
-	/* KISS and expect everything to be page-aligned */
-	if (GEM_WARN_ON(size == 0) ||
-	    GEM_WARN_ON(!IS_ALIGNED(size, mem->min_page_size)) ||
-	    GEM_WARN_ON(!IS_ALIGNED(stolen_offset, mem->min_page_size)))
-		return ERR_PTR(-EINVAL);
-
-	stolen = kzalloc(sizeof(*stolen), GFP_KERNEL);
-	if (!stolen)
-		return ERR_PTR(-ENOMEM);
-
-	stolen->start = stolen_offset;
-	stolen->size = size;
-	mutex_lock(&i915->mm.stolen_lock);
-	ret = drm_mm_reserve_node(&i915->mm.stolen, stolen);
-	mutex_unlock(&i915->mm.stolen_lock);
-	if (ret)
-		goto err_free;
-
-	obj = i915_gem_object_alloc();
-	if (!obj) {
-		ret = -ENOMEM;
-		goto err_stolen;
-	}
-
-	ret = __i915_gem_object_create_stolen(mem, obj, stolen);
-	if (ret)
-		goto err_object_free;
-
-	i915_gem_object_set_cache_coherency(obj, I915_CACHE_NONE);
-	return obj;
-
-err_object_free:
-	i915_gem_object_free(obj);
-err_stolen:
-	i915_gem_stolen_remove_node(i915, stolen);
-err_free:
-	kfree(stolen);
-	return ERR_PTR(ret);
-}
-
 bool i915_gem_object_is_stolen(const struct drm_i915_gem_object *obj)
 {
 	return obj->ops == &i915_gem_object_stolen_ops;

drivers/gpu/drm/i915/gem/i915_gem_stolen.h

@@ -31,10 +31,6 @@ i915_gem_stolen_lmem_setup(struct drm_i915_private *i915, u16 type,
 struct drm_i915_gem_object *
 i915_gem_object_create_stolen(struct drm_i915_private *dev_priv,
 			      resource_size_t size);
-struct drm_i915_gem_object *
-i915_gem_object_create_stolen_for_preallocated(struct drm_i915_private *dev_priv,
-					       resource_size_t stolen_offset,
-					       resource_size_t size);
 
 bool i915_gem_object_is_stolen(const struct drm_i915_gem_object *obj);
 

drivers/gpu/drm/i915/gem/i915_gem_ttm.c

@@ -1142,6 +1142,7 @@ void i915_ttm_bo_destroy(struct ttm_buffer_object *bo)
  */
 int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
 			       struct drm_i915_gem_object *obj,
+			       resource_size_t offset,
 			       resource_size_t size,
 			       resource_size_t page_size,
 			       unsigned int flags)

drivers/gpu/drm/i915/gem/i915_gem_ttm.h

@@ -45,6 +45,7 @@ i915_ttm_to_gem(struct ttm_buffer_object *bo)
 
 int __i915_gem_ttm_object_init(struct intel_memory_region *mem,
 			       struct drm_i915_gem_object *obj,
+			       resource_size_t offset,
 			       resource_size_t size,
 			       resource_size_t page_size,
 			       unsigned int flags);

drivers/gpu/drm/i915/gt/intel_rc6.c

@@ -5,6 +5,7 @@
 
 #include <linux/pm_runtime.h>
 
+#include "gem/i915_gem_region.h"
 #include "i915_drv.h"
 #include "i915_reg.h"
 #include "i915_vgpu.h"
@@ -324,9 +325,10 @@ static int vlv_rc6_init(struct intel_rc6 *rc6)
 		resource_size_t pcbr_offset;
 
 		pcbr_offset = (pcbr & ~4095) - i915->dsm.start;
-		pctx = i915_gem_object_create_stolen_for_preallocated(i915,
+		pctx = i915_gem_object_create_region_at(i915->mm.stolen_region,
 							pcbr_offset,
-								      pctx_size);
+							pctx_size,
+							0);
 		if (IS_ERR(pctx))
 			return PTR_ERR(pctx);
 

drivers/gpu/drm/i915/intel_memory_region.h

@@ -54,6 +54,7 @@ struct intel_memory_region_ops {
 
 	int (*init_object)(struct intel_memory_region *mem,
 			   struct drm_i915_gem_object *obj,
+			   resource_size_t offset,
 			   resource_size_t size,
 			   resource_size_t page_size,
 			   unsigned int flags);

drivers/gpu/drm/i915/selftests/mock_region.c

@@ -57,6 +57,7 @@ static const struct drm_i915_gem_object_ops mock_region_obj_ops = {
 
 static int mock_object_init(struct intel_memory_region *mem,
 			    struct drm_i915_gem_object *obj,
+			    resource_size_t offset,
 			    resource_size_t size,
 			    resource_size_t page_size,
 			    unsigned int flags)