1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_region_ttm.c b/drivers/gpu/drm/i915/intel_region_ttm.c
new file mode 100644
index 000000000000..c8ac118c21f6
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_region_ttm.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2021 Intel Corporation
+ */
+#include <drm/ttm/ttm_bo_driver.h>
+#include <drm/ttm/ttm_device.h>
+
+#include "i915_drv.h"
+#include "i915_scatterlist.h"
+
+#include "intel_region_ttm.h"
+
+/**
+ * DOC: TTM support structure
+ *
+ * The code in this file deals with setting up memory managers for TTM
+ * LMEM and MOCK regions and converting the output from
+ * the managers to struct sg_table, Basically providing the mapping from
+ * i915 GEM regions to TTM memory types and resource managers.
+ */
+
+/* A Zero-initialized driver for now. We don't have a TTM backend yet. */
+static struct ttm_device_funcs i915_ttm_bo_driver;
+
+/**
+ * intel_region_ttm_device_init - Initialize a TTM device
+ * @dev_priv: Pointer to an i915 device private structure.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int intel_region_ttm_device_init(struct drm_i915_private *dev_priv)
+{
+	struct drm_device *drm = &dev_priv->drm;
+
+	return ttm_device_init(&dev_priv->bdev, &i915_ttm_bo_driver,
+			       drm->dev, drm->anon_inode->i_mapping,
+			       drm->vma_offset_manager, false, false);
+}
+
+/**
+ * intel_region_ttm_device_fini - Finalize a TTM device
+ * @dev_priv: Pointer to an i915 device private structure.
+ */
+void intel_region_ttm_device_fini(struct drm_i915_private *dev_priv)
+{
+	ttm_device_fini(&dev_priv->bdev);
+}
+
+/*
+ * Map the i915 memory regions to TTM memory types. We use the
+ * driver-private types for now, reserving TTM_PL_VRAM for stolen
+ * memory and TTM_PL_TT for GGTT use if decided to implement this.
+ */
+static int intel_region_to_ttm_type(struct intel_memory_region *mem)
+{
+	int type;
+
+	GEM_BUG_ON(mem->type != INTEL_MEMORY_LOCAL &&
+		   mem->type != INTEL_MEMORY_MOCK);
+
+	type = mem->instance + TTM_PL_PRIV;
+	GEM_BUG_ON(type >= TTM_NUM_MEM_TYPES);
+
+	return type;
+}
+
+static void *intel_region_ttm_node_reserve(struct intel_memory_region *mem,
+					   resource_size_t offset,
+					   resource_size_t size)
+{
+	struct ttm_resource_manager *man = mem->region_private;
+	struct ttm_place place = {};
+	struct ttm_resource res = {};
+	struct ttm_buffer_object mock_bo = {};
+	int ret;
+
+	/*
+	 * Having to use a mock_bo is unfortunate but stems from some
+	 * drivers having private managers that insist to know what the
+	 * allocate memory is intended for, using it to send private
+	 * data to the manager. Also recently the bo has been used to send
+	 * alignment info to the manager. Assume that apart from the latter,
+	 * none of the managers we use will ever access the buffer object
+	 * members, hoping we can pass the alignment info in the
+	 * struct ttm_place in the future.
+	 */
+
+	place.fpfn = offset >> PAGE_SHIFT;
+	place.lpfn = place.fpfn + (size >> PAGE_SHIFT);
+	res.num_pages = size >> PAGE_SHIFT;
+	ret = man->func->alloc(man, &mock_bo, &place, &res);
+	if (ret == -ENOSPC)
+		ret = -ENXIO;
+
+	return ret ? ERR_PTR(ret) : res.mm_node;
+}
+
+/**
+ * intel_region_ttm_node_free - Free a node allocated from a resource manager
+ * @mem: The region the node was allocated from.
+ * @node: The opaque node representing an allocation.
+ */
+void intel_region_ttm_node_free(struct intel_memory_region *mem,
+				void *node)
+{
+	struct ttm_resource_manager *man = mem->region_private;
+	struct ttm_resource res = {};
+
+	res.mm_node = node;
+	man->func->free(man, &res);
+}
+
+static const struct intel_memory_region_private_ops priv_ops = {
+	.reserve = intel_region_ttm_node_reserve,
+	.free = intel_region_ttm_node_free,
+};
+
+int intel_region_ttm_init(struct intel_memory_region *mem)
+{
+	struct ttm_device *bdev = &mem->i915->bdev;
+	int mem_type = intel_region_to_ttm_type(mem);
+	int ret;
+
+	ret = ttm_range_man_init(bdev, mem_type, false,
+				 resource_size(&mem->region) >> PAGE_SHIFT);
+	if (ret)
+		return ret;
+
+	mem->chunk_size = PAGE_SIZE;
+	mem->max_order =
+		get_order(rounddown_pow_of_two(resource_size(&mem->region)));
+	mem->is_range_manager = true;
+	mem->priv_ops = &priv_ops;
+	mem->region_private = ttm_manager_type(bdev, mem_type);
+
+	return 0;
+}
+
+/**
+ * intel_region_ttm_fini - Finalize a TTM region.
+ * @mem: The memory region
+ *
+ * This functions takes down the TTM resource manager associated with the
+ * memory region, and if it was registered with the TTM device,
+ * removes that registration.
+ */
+void intel_region_ttm_fini(struct intel_memory_region *mem)
+{
+	int ret;
+
+	ret = ttm_range_man_fini(&mem->i915->bdev,
+				 intel_region_to_ttm_type(mem));
+	GEM_WARN_ON(ret);
+	mem->region_private = NULL;
+}
+
+/**
+ * intel_region_ttm_node_to_st - Convert an opaque TTM resource manager node
+ * to an sg_table.
+ * @mem: The memory region.
+ * @node: The resource manager node obtained from the TTM resource manager.
+ *
+ * The gem backends typically use sg-tables for operations on the underlying
+ * io_memory. So provide a way for the backends to translate the
+ * nodes they are handed from TTM to sg-tables.
+ *
+ * Return: A malloced sg_table on success, an error pointer on failure.
+ */
+struct sg_table *intel_region_ttm_node_to_st(struct intel_memory_region *mem,
+					     void *node)
+{
+	return i915_sg_from_mm_node(node, mem->region.start);
+}
+
+/**
+ * intel_region_ttm_node_alloc - Allocate memory resources from a region
+ * @mem: The memory region,
+ * @size: The requested size in bytes
+ * @flags: Allocation flags
+ *
+ * This functionality is provided only for callers that need to allocate
+ * memory from standalone TTM range managers, without the TTM eviction
+ * functionality. Don't use if you are not completely sure that's the
+ * case. The returned opaque node can be converted to an sg_table using
+ * intel_region_ttm_node_to_st(), and can be freed using
+ * intel_region_ttm_node_free().
+ *
+ * Return: A valid pointer on success, an error pointer on failure.
+ */
+void *intel_region_ttm_node_alloc(struct intel_memory_region *mem,
+				  resource_size_t size,
+				  unsigned int flags)
+{
+	struct ttm_resource_manager *man = mem->region_private;
+	struct ttm_place place = {};
+	struct ttm_resource res = {};
+	struct ttm_buffer_object mock_bo = {};
+	int ret;
+
+	/*
+	 * We ignore the flags for now since we're using the range
+	 * manager and contigous and min page size would be fulfilled
+	 * by default if size is min page size aligned.
+	 */
+	res.num_pages = size >> PAGE_SHIFT;
+
+	if (mem->is_range_manager) {
+		if (size >= SZ_1G)
+			mock_bo.page_alignment = SZ_1G >> PAGE_SHIFT;
+		else if (size >= SZ_2M)
+			mock_bo.page_alignment = SZ_2M >> PAGE_SHIFT;
+		else if (size >= SZ_64K)
+			mock_bo.page_alignment = SZ_64K >> PAGE_SHIFT;
+	}
+
+	ret = man->func->alloc(man, &mock_bo, &place, &res);
+	if (ret == -ENOSPC)
+		ret = -ENXIO;
+	return ret ? ERR_PTR(ret) : res.mm_node;
+}