Line data Source code
1 : /*
2 : * Copyright © 2014 Intel Corporation
3 : *
4 : * Permission is hereby granted, free of charge, to any person obtaining a
5 : * copy of this software and associated documentation files (the "Software"),
6 : * to deal in the Software without restriction, including without limitation
7 : * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 : * and/or sell copies of the Software, and to permit persons to whom the
9 : * Software is furnished to do so, subject to the following conditions:
10 : *
11 : * The above copyright notice and this permission notice (including the next
12 : * paragraph) shall be included in all copies or substantial portions of the
13 : * Software.
14 : *
15 : * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 : * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 : * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 : * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 : * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 : * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 : * IN THE SOFTWARE.
22 : *
23 : */
24 :
25 : #include "i915_drv.h"
26 : #include "i915_gem_batch_pool.h"
27 :
28 : /**
29 : * DOC: batch pool
30 : *
31 : * In order to submit batch buffers as 'secure', the software command parser
32 : * must ensure that a batch buffer cannot be modified after parsing. It does
33 : * this by copying the user provided batch buffer contents to a kernel owned
34 : * buffer from which the hardware will actually execute, and by carefully
35 : * managing the address space bindings for such buffers.
36 : *
37 : * The batch pool framework provides a mechanism for the driver to manage a
38 : * set of scratch buffers to use for this purpose. The framework can be
39 : * extended to support other uses cases should they arise.
40 : */
41 :
42 : /**
43 : * i915_gem_batch_pool_init() - initialize a batch buffer pool
44 : * @dev: the drm device
45 : * @pool: the batch buffer pool
46 : */
47 0 : void i915_gem_batch_pool_init(struct drm_device *dev,
48 : struct i915_gem_batch_pool *pool)
49 : {
50 : int n;
51 :
52 0 : pool->dev = dev;
53 :
54 0 : for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++)
55 0 : INIT_LIST_HEAD(&pool->cache_list[n]);
56 0 : }
57 :
58 : /**
59 : * i915_gem_batch_pool_fini() - clean up a batch buffer pool
60 : * @pool: the pool to clean up
61 : *
62 : * Note: Callers must hold the struct_mutex.
63 : */
64 0 : void i915_gem_batch_pool_fini(struct i915_gem_batch_pool *pool)
65 : {
66 : int n;
67 :
68 0 : WARN_ON(!mutex_is_locked(&pool->dev->struct_mutex));
69 :
70 0 : for (n = 0; n < ARRAY_SIZE(pool->cache_list); n++) {
71 0 : while (!list_empty(&pool->cache_list[n])) {
72 : struct drm_i915_gem_object *obj =
73 0 : list_first_entry(&pool->cache_list[n],
74 : struct drm_i915_gem_object,
75 : batch_pool_link);
76 :
77 0 : list_del(&obj->batch_pool_link);
78 0 : drm_gem_object_unreference(&obj->base);
79 : }
80 : }
81 0 : }
82 :
83 : /**
84 : * i915_gem_batch_pool_get() - allocate a buffer from the pool
85 : * @pool: the batch buffer pool
86 : * @size: the minimum desired size of the returned buffer
87 : *
88 : * Returns an inactive buffer from @pool with at least @size bytes,
89 : * with the pages pinned. The caller must i915_gem_object_unpin_pages()
90 : * on the returned object.
91 : *
92 : * Note: Callers must hold the struct_mutex
93 : *
94 : * Return: the buffer object or an error pointer
95 : */
96 : struct drm_i915_gem_object *
97 0 : i915_gem_batch_pool_get(struct i915_gem_batch_pool *pool,
98 : size_t size)
99 : {
100 : struct drm_i915_gem_object *obj = NULL;
101 : struct drm_i915_gem_object *tmp, *next;
102 : struct list_head *list;
103 : int n;
104 :
105 0 : WARN_ON(!mutex_is_locked(&pool->dev->struct_mutex));
106 :
107 : /* Compute a power-of-two bucket, but throw everything greater than
108 : * 16KiB into the same bucket: i.e. the the buckets hold objects of
109 : * (1 page, 2 pages, 4 pages, 8+ pages).
110 : */
111 0 : n = fls(size >> PAGE_SHIFT) - 1;
112 0 : if (n >= ARRAY_SIZE(pool->cache_list))
113 : n = ARRAY_SIZE(pool->cache_list) - 1;
114 0 : list = &pool->cache_list[n];
115 :
116 0 : list_for_each_entry_safe(tmp, next, list, batch_pool_link) {
117 : /* The batches are strictly LRU ordered */
118 0 : if (tmp->active)
119 : break;
120 :
121 : /* While we're looping, do some clean up */
122 0 : if (tmp->madv == __I915_MADV_PURGED) {
123 0 : list_del(&tmp->batch_pool_link);
124 0 : drm_gem_object_unreference(&tmp->base);
125 0 : continue;
126 : }
127 :
128 0 : if (tmp->base.size >= size) {
129 : obj = tmp;
130 0 : break;
131 : }
132 : }
133 :
134 0 : if (obj == NULL) {
135 : int ret;
136 :
137 0 : obj = i915_gem_alloc_object(pool->dev, size);
138 0 : if (obj == NULL)
139 0 : return ERR_PTR(-ENOMEM);
140 :
141 0 : ret = i915_gem_object_get_pages(obj);
142 0 : if (ret)
143 0 : return ERR_PTR(ret);
144 :
145 0 : obj->madv = I915_MADV_DONTNEED;
146 0 : }
147 :
148 0 : list_move_tail(&obj->batch_pool_link, list);
149 0 : i915_gem_object_pin_pages(obj);
150 0 : return obj;
151 0 : }
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