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 int intel_region_ttm_fini(struct intel_memory_region *mem)
108 {
109 	struct ttm_resource_manager *man = mem->region_private;
110 	int ret = -EBUSY;
111 	int count;
112 
113 	/*
114 	 * Put the region's move fences. This releases requests that
115 	 * may hold on to contexts and vms that may hold on to buffer
116 	 * objects placed in this region.
117 	 */
118 	if (man)
119 		ttm_resource_manager_cleanup(man);
120 
121 	/* Flush objects from region. */
122 	for (count = 0; count < 10; ++count) {
123 		i915_gem_flush_free_objects(mem->i915);
124 
125 		mutex_lock(&mem->objects.lock);
126 		if (list_empty(&mem->objects.list))
127 			ret = 0;
128 		mutex_unlock(&mem->objects.lock);
129 		if (!ret)
130 			break;
131 
132 		msleep(20);
133 		flush_delayed_work(&mem->i915->bdev.wq);
134 	}
135 
136 	/* If we leaked objects, Don't free the region causing use after free */
137 	if (ret || !man)
138 		return ret;
139 
140 	ret = i915_ttm_buddy_man_fini(&mem->i915->bdev,
141 				      intel_region_to_ttm_type(mem));
142 	GEM_WARN_ON(ret);
143 	mem->region_private = NULL;
144 
145 	return ret;
146 }
147 
148 /**
149  * intel_region_ttm_resource_to_rsgt -
150  * Convert an opaque TTM resource manager resource to a refcounted sg_table.
151  * @mem: The memory region.
152  * @res: The resource manager resource obtained from the TTM resource manager.
153  *
154  * The gem backends typically use sg-tables for operations on the underlying
155  * io_memory. So provide a way for the backends to translate the
156  * nodes they are handed from TTM to sg-tables.
157  *
158  * Return: A malloced sg_table on success, an error pointer on failure.
159  */
160 struct i915_refct_sgt *
161 intel_region_ttm_resource_to_rsgt(struct intel_memory_region *mem,
162 				  struct ttm_resource *res)
163 {
164 	if (mem->is_range_manager) {
165 		struct ttm_range_mgr_node *range_node =
166 			to_ttm_range_mgr_node(res);
167 
168 		return i915_rsgt_from_mm_node(&range_node->mm_nodes[0],
169 					      mem->region.start);
170 	} else {
171 		return i915_rsgt_from_buddy_resource(res, mem->region.start);
172 	}
173 }
174 
175 #ifdef CONFIG_DRM_I915_SELFTEST
176 /**
177  * intel_region_ttm_resource_alloc - Allocate memory resources from a region
178  * @mem: The memory region,
179  * @size: The requested size in bytes
180  * @flags: Allocation flags
181  *
182  * This functionality is provided only for callers that need to allocate
183  * memory from standalone TTM range managers, without the TTM eviction
184  * functionality. Don't use if you are not completely sure that's the
185  * case. The returned opaque node can be converted to an sg_table using
186  * intel_region_ttm_resource_to_st(), and can be freed using
187  * intel_region_ttm_resource_free().
188  *
189  * Return: A valid pointer on success, an error pointer on failure.
190  */
191 struct ttm_resource *
192 intel_region_ttm_resource_alloc(struct intel_memory_region *mem,
193 				resource_size_t size,
194 				unsigned int flags)
195 {
196 	struct ttm_resource_manager *man = mem->region_private;
197 	struct ttm_place place = {};
198 	struct ttm_buffer_object mock_bo = {};
199 	struct ttm_resource *res;
200 	int ret;
201 
202 	mock_bo.base.size = size;
203 	place.flags = flags;
204 
205 	ret = man->func->alloc(man, &mock_bo, &place, &res);
206 	if (ret == -ENOSPC)
207 		ret = -ENXIO;
208 	return ret ? ERR_PTR(ret) : res;
209 }
210 
211 #endif
212 
213 /**
214  * intel_region_ttm_resource_free - Free a resource allocated from a resource manager
215  * @mem: The region the resource was allocated from.
216  * @res: The opaque resource representing an allocation.
217  */
218 void intel_region_ttm_resource_free(struct intel_memory_region *mem,
219 				    struct ttm_resource *res)
220 {
221 	struct ttm_resource_manager *man = mem->region_private;
222 
223 	man->func->free(man, res);
224 }
225