drm/i915/ttm Initialize the ttm device and memory managers

Temporarily remove the buddy allocator and related selftests
and hook up the TTM range manager for i915 regions.

Also modify the mock region selftests somewhat to account for a
fragmenting manager.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210602083818.241793-2-thomas.hellstrom@linux.intel.com

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;
+}