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 #include "i915_ttm_buddy_manager.h"
12 
13 #include "intel_region_ttm.h"
14 
15 #include "gem/i915_gem_ttm.h" /* For the funcs/ops export only */
16 /**
17  * DOC: TTM support structure
18  *
19  * The code in this file deals with setting up memory managers for TTM
20  * LMEM and MOCK regions and converting the output from
21  * the managers to struct sg_table, Basically providing the mapping from
22  * i915 GEM regions to TTM memory types and resource managers.
23  */
24 
25 /**
26  * intel_region_ttm_device_init - Initialize a TTM device
27  * @dev_priv: Pointer to an i915 device private structure.
28  *
29  * Return: 0 on success, negative error code on failure.
30  */
31 int intel_region_ttm_device_init(struct drm_i915_private *dev_priv)
32 {
33 	struct drm_device *drm = &dev_priv->drm;
34 
35 	return ttm_device_init(&dev_priv->bdev, i915_ttm_driver(),
36 			       drm->dev, drm->anon_inode->i_mapping,
37 			       drm->vma_offset_manager, false, false);
38 }
39 
40 /**
41  * intel_region_ttm_device_fini - Finalize a TTM device
42  * @dev_priv: Pointer to an i915 device private structure.
43  */
44 void intel_region_ttm_device_fini(struct drm_i915_private *dev_priv)
45 {
46 	ttm_device_fini(&dev_priv->bdev);
47 }
48 
49 /*
50  * Map the i915 memory regions to TTM memory types. We use the
51  * driver-private types for now, reserving TTM_PL_VRAM for stolen
52  * memory and TTM_PL_TT for GGTT use if decided to implement this.
53  */
54 int intel_region_to_ttm_type(const struct intel_memory_region *mem)
55 {
56 	int type;
57 
58 	GEM_BUG_ON(mem->type != INTEL_MEMORY_LOCAL &&
59 		   mem->type != INTEL_MEMORY_MOCK &&
60 		   mem->type != INTEL_MEMORY_SYSTEM);
61 
62 	if (mem->type == INTEL_MEMORY_SYSTEM)
63 		return TTM_PL_SYSTEM;
64 
65 	type = mem->instance + TTM_PL_PRIV;
66 	GEM_BUG_ON(type >= TTM_NUM_MEM_TYPES);
67 
68 	return type;
69 }
70 
71 /**
72  * intel_region_ttm_init - Initialize a memory region for TTM.
73  * @mem: The region to initialize.
74  *
75  * This function initializes a suitable TTM resource manager for the
76  * region, and if it's a LMEM region type, attaches it to the TTM
77  * device. MOCK regions are NOT attached to the TTM device, since we don't
78  * have one for the mock selftests.
79  *
80  * Return: 0 on success, negative error code on failure.
81  */
82 int intel_region_ttm_init(struct intel_memory_region *mem)
83 {
84 	struct ttm_device *bdev = &mem->i915->bdev;
85 	int mem_type = intel_region_to_ttm_type(mem);
86 	int ret;
87 
88 	ret = i915_ttm_buddy_man_init(bdev, mem_type, false,
89 				      resource_size(&mem->region),
90 				      mem->min_page_size, PAGE_SIZE);
91 	if (ret)
92 		return ret;
93 
94 	mem->region_private = ttm_manager_type(bdev, mem_type);
95 
96 	return 0;
97 }
98 
99 /**
100  * intel_region_ttm_fini - Finalize a TTM region.
101  * @mem: The memory region
102  *
103  * This functions takes down the TTM resource manager associated with the
104  * memory region, and if it was registered with the TTM device,
105  * removes that registration.
106  */
107 void intel_region_ttm_fini(struct intel_memory_region *mem)
108 {
109 	int ret;
110 
111 	ret = i915_ttm_buddy_man_fini(&mem->i915->bdev,
112 				      intel_region_to_ttm_type(mem));
113 	GEM_WARN_ON(ret);
114 	mem->region_private = NULL;
115 }
116 
117 /**
118  * intel_region_ttm_resource_to_st - Convert an opaque TTM resource manager resource
119  * to an sg_table.
120  * @mem: The memory region.
121  * @res: The resource manager resource obtained from the TTM resource manager.
122  *
123  * The gem backends typically use sg-tables for operations on the underlying
124  * io_memory. So provide a way for the backends to translate the
125  * nodes they are handed from TTM to sg-tables.
126  *
127  * Return: A malloced sg_table on success, an error pointer on failure.
128  */
129 struct sg_table *intel_region_ttm_resource_to_st(struct intel_memory_region *mem,
130 						 struct ttm_resource *res)
131 {
132 	if (mem->is_range_manager) {
133 		struct ttm_range_mgr_node *range_node =
134 			to_ttm_range_mgr_node(res);
135 
136 		return i915_sg_from_mm_node(&range_node->mm_nodes[0],
137 					    mem->region.start);
138 	} else {
139 		return i915_sg_from_buddy_resource(res, mem->region.start);
140 	}
141 }
142 
143 #ifdef CONFIG_DRM_I915_SELFTEST
144 /**
145  * intel_region_ttm_resource_alloc - Allocate memory resources from a region
146  * @mem: The memory region,
147  * @size: The requested size in bytes
148  * @flags: Allocation flags
149  *
150  * This functionality is provided only for callers that need to allocate
151  * memory from standalone TTM range managers, without the TTM eviction
152  * functionality. Don't use if you are not completely sure that's the
153  * case. The returned opaque node can be converted to an sg_table using
154  * intel_region_ttm_resource_to_st(), and can be freed using
155  * intel_region_ttm_resource_free().
156  *
157  * Return: A valid pointer on success, an error pointer on failure.
158  */
159 struct ttm_resource *
160 intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
161 				resource_size_t size,
162 				unsigned int flags)
163 {
164 	struct ttm_resource_manager *man = mem->region_private;
165 	struct ttm_place place = {};
166 	struct ttm_buffer_object mock_bo = {};
167 	struct ttm_resource *res;
168 	int ret;
169 
170 	mock_bo.base.size = size;
171 	place.flags = flags;
172 
173 	ret = man->func->alloc(man, &mock_bo, &place, &res);
174 	if (ret == -ENOSPC)
175 		ret = -ENXIO;
176 	return ret ? ERR_PTR(ret) : res;
177 }
178 
179 #endif
180 
181 /**
182  * intel_region_ttm_resource_free - Free a resource allocated from a resource manager
183  * @mem: The region the resource was allocated from.
184  * @res: The opaque resource representing an allocation.
185  */
186 void intel_region_ttm_resource_free(struct intel_memory_region *mem,
187 				    struct ttm_resource *res)
188 {
189 	struct ttm_resource_manager *man = mem->region_private;
190 
191 	man->func->free(man, res);
192 }
193