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_region.h"
16 #include "gem/i915_gem_ttm.h" /* For the funcs/ops export only */
17 /**
18 * DOC: TTM support structure
19 *
20 * The code in this file deals with setting up memory managers for TTM
21 * LMEM and MOCK regions and converting the output from
22 * the managers to struct sg_table, Basically providing the mapping from
23 * i915 GEM regions to TTM memory types and resource managers.
24 */
25
26 /**
27 * intel_region_ttm_device_init - Initialize a TTM device
28 * @dev_priv: Pointer to an i915 device private structure.
29 *
30 * Return: 0 on success, negative error code on failure.
31 */
intel_region_ttm_device_init(struct drm_i915_private * dev_priv)32 int intel_region_ttm_device_init(struct drm_i915_private *dev_priv)
33 {
34 struct drm_device *drm = &dev_priv->drm;
35
36 return ttm_device_init(&dev_priv->bdev, i915_ttm_driver(),
37 drm->dev, drm->anon_inode->i_mapping,
38 drm->vma_offset_manager, false, false);
39 }
40
41 /**
42 * intel_region_ttm_device_fini - Finalize a TTM device
43 * @dev_priv: Pointer to an i915 device private structure.
44 */
intel_region_ttm_device_fini(struct drm_i915_private * dev_priv)45 void intel_region_ttm_device_fini(struct drm_i915_private *dev_priv)
46 {
47 ttm_device_fini(&dev_priv->bdev);
48 }
49
50 /*
51 * Map the i915 memory regions to TTM memory types. We use the
52 * driver-private types for now, reserving TTM_PL_VRAM for stolen
53 * memory and TTM_PL_TT for GGTT use if decided to implement this.
54 */
intel_region_to_ttm_type(const struct intel_memory_region * mem)55 int intel_region_to_ttm_type(const struct intel_memory_region *mem)
56 {
57 int type;
58
59 GEM_BUG_ON(mem->type != INTEL_MEMORY_LOCAL &&
60 mem->type != INTEL_MEMORY_MOCK &&
61 mem->type != INTEL_MEMORY_SYSTEM);
62
63 if (mem->type == INTEL_MEMORY_SYSTEM)
64 return TTM_PL_SYSTEM;
65
66 type = mem->instance + TTM_PL_PRIV;
67 GEM_BUG_ON(type >= TTM_NUM_MEM_TYPES);
68
69 return type;
70 }
71
72 /**
73 * intel_region_ttm_init - Initialize a memory region for TTM.
74 * @mem: The region to initialize.
75 *
76 * This function initializes a suitable TTM resource manager for the
77 * region, and if it's a LMEM region type, attaches it to the TTM
78 * device. MOCK regions are NOT attached to the TTM device, since we don't
79 * have one for the mock selftests.
80 *
81 * Return: 0 on success, negative error code on failure.
82 */
intel_region_ttm_init(struct intel_memory_region * mem)83 int intel_region_ttm_init(struct intel_memory_region *mem)
84 {
85 struct ttm_device *bdev = &mem->i915->bdev;
86 int mem_type = intel_region_to_ttm_type(mem);
87 int ret;
88
89 ret = i915_ttm_buddy_man_init(bdev, mem_type, false,
90 resource_size(&mem->region),
91 mem->io_size,
92 mem->min_page_size, PAGE_SIZE);
93 if (ret)
94 return ret;
95
96 mem->region_private = ttm_manager_type(bdev, mem_type);
97
98 return 0;
99 }
100
101 /**
102 * intel_region_ttm_fini - Finalize a TTM region.
103 * @mem: The memory region
104 *
105 * This functions takes down the TTM resource manager associated with the
106 * memory region, and if it was registered with the TTM device,
107 * removes that registration.
108 */
intel_region_ttm_fini(struct intel_memory_region * mem)109 int intel_region_ttm_fini(struct intel_memory_region *mem)
110 {
111 struct ttm_resource_manager *man = mem->region_private;
112 int ret = -EBUSY;
113 int count;
114
115 /*
116 * Put the region's move fences. This releases requests that
117 * may hold on to contexts and vms that may hold on to buffer
118 * objects placed in this region.
119 */
120 if (man)
121 ttm_resource_manager_cleanup(man);
122
123 /* Flush objects from region. */
124 for (count = 0; count < 10; ++count) {
125 i915_gem_flush_free_objects(mem->i915);
126
127 mutex_lock(&mem->objects.lock);
128 if (list_empty(&mem->objects.list))
129 ret = 0;
130 mutex_unlock(&mem->objects.lock);
131 if (!ret)
132 break;
133
134 msleep(20);
135 flush_delayed_work(&mem->i915->bdev.wq);
136 }
137
138 /* If we leaked objects, Don't free the region causing use after free */
139 if (ret || !man)
140 return ret;
141
142 ret = i915_ttm_buddy_man_fini(&mem->i915->bdev,
143 intel_region_to_ttm_type(mem));
144 GEM_WARN_ON(ret);
145 mem->region_private = NULL;
146
147 return ret;
148 }
149
150 /**
151 * intel_region_ttm_resource_to_rsgt -
152 * Convert an opaque TTM resource manager resource to a refcounted sg_table.
153 * @mem: The memory region.
154 * @res: The resource manager resource obtained from the TTM resource manager.
155 * @page_alignment: Required page alignment for each sg entry. Power of two.
156 *
157 * The gem backends typically use sg-tables for operations on the underlying
158 * io_memory. So provide a way for the backends to translate the
159 * nodes they are handed from TTM to sg-tables.
160 *
161 * Return: A malloced sg_table on success, an error pointer on failure.
162 */
163 struct i915_refct_sgt *
intel_region_ttm_resource_to_rsgt(struct intel_memory_region * mem,struct ttm_resource * res,u32 page_alignment)164 intel_region_ttm_resource_to_rsgt(struct intel_memory_region *mem,
165 struct ttm_resource *res,
166 u32 page_alignment)
167 {
168 if (mem->is_range_manager) {
169 struct ttm_range_mgr_node *range_node =
170 to_ttm_range_mgr_node(res);
171
172 return i915_rsgt_from_mm_node(&range_node->mm_nodes[0],
173 mem->region.start,
174 page_alignment);
175 } else {
176 return i915_rsgt_from_buddy_resource(res, mem->region.start,
177 page_alignment);
178 }
179 }
180
181 #ifdef CONFIG_DRM_I915_SELFTEST
182 /**
183 * intel_region_ttm_resource_alloc - Allocate memory resources from a region
184 * @mem: The memory region,
185 * @size: The requested size in bytes
186 * @flags: Allocation flags
187 *
188 * This functionality is provided only for callers that need to allocate
189 * memory from standalone TTM range managers, without the TTM eviction
190 * functionality. Don't use if you are not completely sure that's the
191 * case. The returned opaque node can be converted to an sg_table using
192 * intel_region_ttm_resource_to_st(), and can be freed using
193 * intel_region_ttm_resource_free().
194 *
195 * Return: A valid pointer on success, an error pointer on failure.
196 */
197 struct ttm_resource *
intel_region_ttm_resource_alloc(struct intel_memory_region * mem,resource_size_t offset,resource_size_t size,unsigned int flags)198 intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
199 resource_size_t offset,
200 resource_size_t size,
201 unsigned int flags)
202 {
203 struct ttm_resource_manager *man = mem->region_private;
204 struct ttm_place place = {};
205 struct ttm_buffer_object mock_bo = {};
206 struct ttm_resource *res;
207 int ret;
208
209 if (flags & I915_BO_ALLOC_CONTIGUOUS)
210 place.flags |= TTM_PL_FLAG_CONTIGUOUS;
211 if (offset != I915_BO_INVALID_OFFSET) {
212 place.fpfn = offset >> PAGE_SHIFT;
213 place.lpfn = place.fpfn + (size >> PAGE_SHIFT);
214 } else if (mem->io_size && mem->io_size < mem->total) {
215 if (flags & I915_BO_ALLOC_GPU_ONLY) {
216 place.flags |= TTM_PL_FLAG_TOPDOWN;
217 } else {
218 place.fpfn = 0;
219 place.lpfn = mem->io_size >> PAGE_SHIFT;
220 }
221 }
222
223 mock_bo.base.size = size;
224 mock_bo.bdev = &mem->i915->bdev;
225
226 ret = man->func->alloc(man, &mock_bo, &place, &res);
227 if (ret == -ENOSPC)
228 ret = -ENXIO;
229 if (!ret)
230 res->bo = NULL; /* Rather blow up, then some uaf */
231 return ret ? ERR_PTR(ret) : res;
232 }
233
234 #endif
235
236 /**
237 * intel_region_ttm_resource_free - Free a resource allocated from a resource manager
238 * @mem: The region the resource was allocated from.
239 * @res: The opaque resource representing an allocation.
240 */
intel_region_ttm_resource_free(struct intel_memory_region * mem,struct ttm_resource * res)241 void intel_region_ttm_resource_free(struct intel_memory_region *mem,
242 struct ttm_resource *res)
243 {
244 struct ttm_resource_manager *man = mem->region_private;
245 struct ttm_buffer_object mock_bo = {};
246
247 mock_bo.base.size = res->num_pages << PAGE_SHIFT;
248 mock_bo.bdev = &mem->i915->bdev;
249 res->bo = &mock_bo;
250
251 man->func->free(man, res);
252 }
253