1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2021 Intel Corporation
4  */
5 #include <drm/ttm/ttm_bo_driver.h>
6 #include <drm/ttm/ttm_device.h>
7 #include <drm/ttm/ttm_range_manager.h>
8 
9 #include "i915_drv.h"
10 #include "i915_scatterlist.h"
11 
12 #include "intel_region_ttm.h"
13 
14 #include "gem/i915_gem_ttm.h" /* For the funcs/ops export only */
15 /**
16  * DOC: TTM support structure
17  *
18  * The code in this file deals with setting up memory managers for TTM
19  * LMEM and MOCK regions and converting the output from
20  * the managers to struct sg_table, Basically providing the mapping from
21  * i915 GEM regions to TTM memory types and resource managers.
22  */
23 
24 /**
25  * intel_region_ttm_device_init - Initialize a TTM device
26  * @dev_priv: Pointer to an i915 device private structure.
27  *
28  * Return: 0 on success, negative error code on failure.
29  */
30 int intel_region_ttm_device_init(struct drm_i915_private *dev_priv)
31 {
32 	struct drm_device *drm = &dev_priv->drm;
33 
34 	return ttm_device_init(&dev_priv->bdev, i915_ttm_driver(),
35 			       drm->dev, drm->anon_inode->i_mapping,
36 			       drm->vma_offset_manager, false, false);
37 }
38 
39 /**
40  * intel_region_ttm_device_fini - Finalize a TTM device
41  * @dev_priv: Pointer to an i915 device private structure.
42  */
43 void intel_region_ttm_device_fini(struct drm_i915_private *dev_priv)
44 {
45 	ttm_device_fini(&dev_priv->bdev);
46 }
47 
48 /*
49  * Map the i915 memory regions to TTM memory types. We use the
50  * driver-private types for now, reserving TTM_PL_VRAM for stolen
51  * memory and TTM_PL_TT for GGTT use if decided to implement this.
52  */
53 static int intel_region_to_ttm_type(struct intel_memory_region *mem)
54 {
55 	int type;
56 
57 	GEM_BUG_ON(mem->type != INTEL_MEMORY_LOCAL &&
58 		   mem->type != INTEL_MEMORY_MOCK);
59 
60 	type = mem->instance + TTM_PL_PRIV;
61 	GEM_BUG_ON(type >= TTM_NUM_MEM_TYPES);
62 
63 	return type;
64 }
65 
66 static struct ttm_resource *
67 intel_region_ttm_node_reserve(struct intel_memory_region *mem,
68 			      resource_size_t offset,
69 			      resource_size_t size)
70 {
71 	struct ttm_resource_manager *man = mem->region_private;
72 	struct ttm_place place = {};
73 	struct ttm_buffer_object mock_bo = {};
74 	struct ttm_resource *res;
75 	int ret;
76 
77 	/*
78 	 * Having to use a mock_bo is unfortunate but stems from some
79 	 * drivers having private managers that insist to know what the
80 	 * allocate memory is intended for, using it to send private
81 	 * data to the manager. Also recently the bo has been used to send
82 	 * alignment info to the manager. Assume that apart from the latter,
83 	 * none of the managers we use will ever access the buffer object
84 	 * members, hoping we can pass the alignment info in the
85 	 * struct ttm_place in the future.
86 	 */
87 
88 	place.fpfn = offset >> PAGE_SHIFT;
89 	place.lpfn = place.fpfn + (size >> PAGE_SHIFT);
90 	mock_bo.base.size = size;
91 	ret = man->func->alloc(man, &mock_bo, &place, &res);
92 	if (ret == -ENOSPC)
93 		ret = -ENXIO;
94 
95 	return ret ? ERR_PTR(ret) : res;
96 }
97 
98 /**
99  * intel_region_ttm_node_free - Free a node allocated from a resource manager
100  * @mem: The region the node was allocated from.
101  * @node: The opaque node representing an allocation.
102  */
103 void intel_region_ttm_node_free(struct intel_memory_region *mem,
104 				struct ttm_resource *res)
105 {
106 	struct ttm_resource_manager *man = mem->region_private;
107 
108 	man->func->free(man, res);
109 }
110 
111 static const struct intel_memory_region_private_ops priv_ops = {
112 	.reserve = intel_region_ttm_node_reserve,
113 	.free = intel_region_ttm_node_free,
114 };
115 
116 int intel_region_ttm_init(struct intel_memory_region *mem)
117 {
118 	struct ttm_device *bdev = &mem->i915->bdev;
119 	int mem_type = intel_region_to_ttm_type(mem);
120 	int ret;
121 
122 	ret = ttm_range_man_init(bdev, mem_type, false,
123 				 resource_size(&mem->region) >> PAGE_SHIFT);
124 	if (ret)
125 		return ret;
126 
127 	mem->chunk_size = PAGE_SIZE;
128 	mem->max_order =
129 		get_order(rounddown_pow_of_two(resource_size(&mem->region)));
130 	mem->is_range_manager = true;
131 	mem->priv_ops = &priv_ops;
132 	mem->region_private = ttm_manager_type(bdev, mem_type);
133 
134 	return 0;
135 }
136 
137 /**
138  * intel_region_ttm_fini - Finalize a TTM region.
139  * @mem: The memory region
140  *
141  * This functions takes down the TTM resource manager associated with the
142  * memory region, and if it was registered with the TTM device,
143  * removes that registration.
144  */
145 void intel_region_ttm_fini(struct intel_memory_region *mem)
146 {
147 	int ret;
148 
149 	ret = ttm_range_man_fini(&mem->i915->bdev,
150 				 intel_region_to_ttm_type(mem));
151 	GEM_WARN_ON(ret);
152 	mem->region_private = NULL;
153 }
154 
155 /**
156  * intel_region_ttm_node_to_st - Convert an opaque TTM resource manager node
157  * to an sg_table.
158  * @mem: The memory region.
159  * @node: The resource manager node obtained from the TTM resource manager.
160  *
161  * The gem backends typically use sg-tables for operations on the underlying
162  * io_memory. So provide a way for the backends to translate the
163  * nodes they are handed from TTM to sg-tables.
164  *
165  * Return: A malloced sg_table on success, an error pointer on failure.
166  */
167 struct sg_table *intel_region_ttm_node_to_st(struct intel_memory_region *mem,
168 					     struct ttm_resource *res)
169 {
170 	struct ttm_range_mgr_node *range_node =
171 		container_of(res, typeof(*range_node), base);
172 
173 	GEM_WARN_ON(!mem->is_range_manager);
174 	return i915_sg_from_mm_node(&range_node->mm_nodes[0],
175 				    mem->region.start);
176 }
177 
178 #ifdef CONFIG_DRM_I915_SELFTEST
179 /**
180  * intel_region_ttm_node_alloc - Allocate memory resources from a region
181  * @mem: The memory region,
182  * @size: The requested size in bytes
183  * @flags: Allocation flags
184  *
185  * This functionality is provided only for callers that need to allocate
186  * memory from standalone TTM range managers, without the TTM eviction
187  * functionality. Don't use if you are not completely sure that's the
188  * case. The returned opaque node can be converted to an sg_table using
189  * intel_region_ttm_node_to_st(), and can be freed using
190  * intel_region_ttm_node_free().
191  *
192  * Return: A valid pointer on success, an error pointer on failure.
193  */
194 struct ttm_resource *
195 intel_region_ttm_node_alloc(struct intel_memory_region *mem,
196 			    resource_size_t size,
197 			    unsigned int flags)
198 {
199 	struct ttm_resource_manager *man = mem->region_private;
200 	struct ttm_place place = {};
201 	struct ttm_buffer_object mock_bo = {};
202 	struct ttm_resource *res;
203 	int ret;
204 
205 	/*
206 	 * We ignore the flags for now since we're using the range
207 	 * manager and contigous and min page size would be fulfilled
208 	 * by default if size is min page size aligned.
209 	 */
210 	mock_bo.base.size = size;
211 
212 	if (mem->is_range_manager) {
213 		if (size >= SZ_1G)
214 			mock_bo.page_alignment = SZ_1G >> PAGE_SHIFT;
215 		else if (size >= SZ_2M)
216 			mock_bo.page_alignment = SZ_2M >> PAGE_SHIFT;
217 		else if (size >= SZ_64K)
218 			mock_bo.page_alignment = SZ_64K >> PAGE_SHIFT;
219 	}
220 
221 	ret = man->func->alloc(man, &mock_bo, &place, &res);
222 	if (ret == -ENOSPC)
223 		ret = -ENXIO;
224 	return ret ? ERR_PTR(ret) : res;
225 }
226 #endif
227