xref: /openbsd/sys/dev/pci/drm/i915/intel_region_ttm.c (revision 9ea232b5)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2021 Intel Corporation
4  */
5 #include <drm/ttm/ttm_device.h>
6 #include <drm/ttm/ttm_range_manager.h>
7 
8 #include "i915_drv.h"
9 #include "i915_scatterlist.h"
10 #include "i915_ttm_buddy_manager.h"
11 
12 #include "intel_region_ttm.h"
13 
14 #include "gem/i915_gem_region.h"
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 #ifdef notyet
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 #else
40 	return ttm_device_init(&dev_priv->bdev, i915_ttm_driver(),
41 			       drm->dev, /*drm->anon_inode->i_mapping*/NULL,
42 			       drm->vma_offset_manager, false, false);
43 #endif
44 }
45 
46 /**
47  * intel_region_ttm_device_fini - Finalize a TTM device
48  * @dev_priv: Pointer to an i915 device private structure.
49  */
50 void intel_region_ttm_device_fini(struct drm_i915_private *dev_priv)
51 {
52 	ttm_device_fini(&dev_priv->bdev);
53 }
54 
55 /*
56  * Map the i915 memory regions to TTM memory types. We use the
57  * driver-private types for now, reserving TTM_PL_VRAM for stolen
58  * memory and TTM_PL_TT for GGTT use if decided to implement this.
59  */
60 int intel_region_to_ttm_type(const struct intel_memory_region *mem)
61 {
62 	int type;
63 
64 	GEM_BUG_ON(mem->type != INTEL_MEMORY_LOCAL &&
65 		   mem->type != INTEL_MEMORY_MOCK &&
66 		   mem->type != INTEL_MEMORY_SYSTEM);
67 
68 	if (mem->type == INTEL_MEMORY_SYSTEM)
69 		return TTM_PL_SYSTEM;
70 
71 	type = mem->instance + TTM_PL_PRIV;
72 	GEM_BUG_ON(type >= TTM_NUM_MEM_TYPES);
73 
74 	return type;
75 }
76 
77 /**
78  * intel_region_ttm_init - Initialize a memory region for TTM.
79  * @mem: The region to initialize.
80  *
81  * This function initializes a suitable TTM resource manager for the
82  * region, and if it's a LMEM region type, attaches it to the TTM
83  * device. MOCK regions are NOT attached to the TTM device, since we don't
84  * have one for the mock selftests.
85  *
86  * Return: 0 on success, negative error code on failure.
87  */
88 int intel_region_ttm_init(struct intel_memory_region *mem)
89 {
90 	struct ttm_device *bdev = &mem->i915->bdev;
91 	int mem_type = intel_region_to_ttm_type(mem);
92 	int ret;
93 
94 	ret = i915_ttm_buddy_man_init(bdev, mem_type, false,
95 				      resource_size(&mem->region),
96 				      mem->io_size,
97 				      mem->min_page_size, PAGE_SIZE);
98 	if (ret)
99 		return ret;
100 
101 	mem->region_private = ttm_manager_type(bdev, mem_type);
102 
103 	return 0;
104 }
105 
106 /**
107  * intel_region_ttm_fini - Finalize a TTM region.
108  * @mem: The memory region
109  *
110  * This functions takes down the TTM resource manager associated with the
111  * memory region, and if it was registered with the TTM device,
112  * removes that registration.
113  */
114 int intel_region_ttm_fini(struct intel_memory_region *mem)
115 {
116 	struct ttm_resource_manager *man = mem->region_private;
117 	int ret = -EBUSY;
118 	int count;
119 
120 	/*
121 	 * Put the region's move fences. This releases requests that
122 	 * may hold on to contexts and vms that may hold on to buffer
123 	 * objects placed in this region.
124 	 */
125 	if (man)
126 		ttm_resource_manager_cleanup(man);
127 
128 	/* Flush objects from region. */
129 	for (count = 0; count < 10; ++count) {
130 		i915_gem_flush_free_objects(mem->i915);
131 
132 		mutex_lock(&mem->objects.lock);
133 		if (list_empty(&mem->objects.list))
134 			ret = 0;
135 		mutex_unlock(&mem->objects.lock);
136 		if (!ret)
137 			break;
138 
139 		drm_msleep(20);
140 		drain_workqueue(mem->i915->bdev.wq);
141 	}
142 
143 	/* If we leaked objects, Don't free the region causing use after free */
144 	if (ret || !man)
145 		return ret;
146 
147 	ret = i915_ttm_buddy_man_fini(&mem->i915->bdev,
148 				      intel_region_to_ttm_type(mem));
149 	GEM_WARN_ON(ret);
150 	mem->region_private = NULL;
151 
152 	return ret;
153 }
154 
155 /**
156  * intel_region_ttm_resource_to_rsgt -
157  * Convert an opaque TTM resource manager resource to a refcounted sg_table.
158  * @mem: The memory region.
159  * @res: The resource manager resource obtained from the TTM resource manager.
160  * @page_alignment: Required page alignment for each sg entry. Power of two.
161  *
162  * The gem backends typically use sg-tables for operations on the underlying
163  * io_memory. So provide a way for the backends to translate the
164  * nodes they are handed from TTM to sg-tables.
165  *
166  * Return: A malloced sg_table on success, an error pointer on failure.
167  */
168 struct i915_refct_sgt *
169 intel_region_ttm_resource_to_rsgt(struct intel_memory_region *mem,
170 				  struct ttm_resource *res,
171 				  u32 page_alignment)
172 {
173 	if (mem->is_range_manager) {
174 		struct ttm_range_mgr_node *range_node =
175 			to_ttm_range_mgr_node(res);
176 
177 		return i915_rsgt_from_mm_node(&range_node->mm_nodes[0],
178 					      mem->region.start,
179 					      page_alignment);
180 	} else {
181 		return i915_rsgt_from_buddy_resource(res, mem->region.start,
182 						     page_alignment);
183 	}
184 }
185 
186 #ifdef CONFIG_DRM_I915_SELFTEST
187 /**
188  * intel_region_ttm_resource_alloc - Allocate memory resources from a region
189  * @mem: The memory region,
190  * @offset: BO offset
191  * @size: The requested size in bytes
192  * @flags: Allocation flags
193  *
194  * This functionality is provided only for callers that need to allocate
195  * memory from standalone TTM range managers, without the TTM eviction
196  * functionality. Don't use if you are not completely sure that's the
197  * case. The returned opaque node can be converted to an sg_table using
198  * intel_region_ttm_resource_to_st(), and can be freed using
199  * intel_region_ttm_resource_free().
200  *
201  * Return: A valid pointer on success, an error pointer on failure.
202  */
203 struct ttm_resource *
204 intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
205 				resource_size_t offset,
206 				resource_size_t size,
207 				unsigned int flags)
208 {
209 	struct ttm_resource_manager *man = mem->region_private;
210 	struct ttm_place place = {};
211 	struct ttm_buffer_object mock_bo = {};
212 	struct ttm_resource *res;
213 	int ret;
214 
215 	if (flags & I915_BO_ALLOC_CONTIGUOUS)
216 		place.flags |= TTM_PL_FLAG_CONTIGUOUS;
217 	if (offset != I915_BO_INVALID_OFFSET) {
218 		if (WARN_ON(overflows_type(offset >> PAGE_SHIFT, place.fpfn))) {
219 			ret = -E2BIG;
220 			goto out;
221 		}
222 		place.fpfn = offset >> PAGE_SHIFT;
223 		if (WARN_ON(overflows_type(place.fpfn + (size >> PAGE_SHIFT), place.lpfn))) {
224 			ret = -E2BIG;
225 			goto out;
226 		}
227 		place.lpfn = place.fpfn + (size >> PAGE_SHIFT);
228 	} else if (mem->io_size && mem->io_size < mem->total) {
229 		if (flags & I915_BO_ALLOC_GPU_ONLY) {
230 			place.flags |= TTM_PL_FLAG_TOPDOWN;
231 		} else {
232 			place.fpfn = 0;
233 			if (WARN_ON(overflows_type(mem->io_size >> PAGE_SHIFT, place.lpfn))) {
234 				ret = -E2BIG;
235 				goto out;
236 			}
237 			place.lpfn = mem->io_size >> PAGE_SHIFT;
238 		}
239 	}
240 
241 	mock_bo.base.size = size;
242 	mock_bo.bdev = &mem->i915->bdev;
243 
244 	ret = man->func->alloc(man, &mock_bo, &place, &res);
245 
246 out:
247 	if (ret == -ENOSPC)
248 		ret = -ENXIO;
249 	if (!ret)
250 		res->bo = NULL; /* Rather blow up, then some uaf */
251 	return ret ? ERR_PTR(ret) : res;
252 }
253 
254 #endif
255 
256 /**
257  * intel_region_ttm_resource_free - Free a resource allocated from a resource manager
258  * @mem: The region the resource was allocated from.
259  * @res: The opaque resource representing an allocation.
260  */
261 void intel_region_ttm_resource_free(struct intel_memory_region *mem,
262 				    struct ttm_resource *res)
263 {
264 	struct ttm_resource_manager *man = mem->region_private;
265 	struct ttm_buffer_object mock_bo = {};
266 
267 	mock_bo.base.size = res->size;
268 	mock_bo.bdev = &mem->i915->bdev;
269 	res->bo = &mock_bo;
270 
271 	man->func->free(man, res);
272 }
273