Brad Volkin | 493018d | 2014-12-11 12:13:08 -0800 | [diff] [blame] | 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 | |
| 27 | /** |
| 28 | * DOC: batch pool |
| 29 | * |
| 30 | * In order to submit batch buffers as 'secure', the software command parser |
| 31 | * must ensure that a batch buffer cannot be modified after parsing. It does |
| 32 | * this by copying the user provided batch buffer contents to a kernel owned |
| 33 | * buffer from which the hardware will actually execute, and by carefully |
| 34 | * managing the address space bindings for such buffers. |
| 35 | * |
| 36 | * The batch pool framework provides a mechanism for the driver to manage a |
| 37 | * set of scratch buffers to use for this purpose. The framework can be |
| 38 | * extended to support other uses cases should they arise. |
| 39 | */ |
| 40 | |
| 41 | /** |
| 42 | * i915_gem_batch_pool_init() - initialize a batch buffer pool |
| 43 | * @dev: the drm device |
| 44 | * @pool: the batch buffer pool |
| 45 | */ |
| 46 | void i915_gem_batch_pool_init(struct drm_device *dev, |
| 47 | struct i915_gem_batch_pool *pool) |
| 48 | { |
| 49 | pool->dev = dev; |
| 50 | INIT_LIST_HEAD(&pool->cache_list); |
| 51 | } |
| 52 | |
| 53 | /** |
| 54 | * i915_gem_batch_pool_fini() - clean up a batch buffer pool |
| 55 | * @pool: the pool to clean up |
| 56 | * |
| 57 | * Note: Callers must hold the struct_mutex. |
| 58 | */ |
| 59 | void i915_gem_batch_pool_fini(struct i915_gem_batch_pool *pool) |
| 60 | { |
| 61 | WARN_ON(!mutex_is_locked(&pool->dev->struct_mutex)); |
| 62 | |
| 63 | while (!list_empty(&pool->cache_list)) { |
| 64 | struct drm_i915_gem_object *obj = |
| 65 | list_first_entry(&pool->cache_list, |
| 66 | struct drm_i915_gem_object, |
| 67 | batch_pool_list); |
| 68 | |
| 69 | WARN_ON(obj->active); |
| 70 | |
| 71 | list_del_init(&obj->batch_pool_list); |
| 72 | drm_gem_object_unreference(&obj->base); |
| 73 | } |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * i915_gem_batch_pool_get() - select a buffer from the pool |
| 78 | * @pool: the batch buffer pool |
| 79 | * @size: the minimum desired size of the returned buffer |
| 80 | * |
| 81 | * Finds or allocates a batch buffer in the pool with at least the requested |
| 82 | * size. The caller is responsible for any domain, active/inactive, or |
| 83 | * purgeability management for the returned buffer. |
| 84 | * |
| 85 | * Note: Callers must hold the struct_mutex |
| 86 | * |
| 87 | * Return: the selected batch buffer object |
| 88 | */ |
| 89 | struct drm_i915_gem_object * |
| 90 | i915_gem_batch_pool_get(struct i915_gem_batch_pool *pool, |
| 91 | size_t size) |
| 92 | { |
| 93 | struct drm_i915_gem_object *obj = NULL; |
| 94 | struct drm_i915_gem_object *tmp, *next; |
| 95 | |
| 96 | WARN_ON(!mutex_is_locked(&pool->dev->struct_mutex)); |
| 97 | |
| 98 | list_for_each_entry_safe(tmp, next, |
| 99 | &pool->cache_list, batch_pool_list) { |
| 100 | |
| 101 | if (tmp->active) |
| 102 | continue; |
| 103 | |
| 104 | /* While we're looping, do some clean up */ |
| 105 | if (tmp->madv == __I915_MADV_PURGED) { |
| 106 | list_del(&tmp->batch_pool_list); |
| 107 | drm_gem_object_unreference(&tmp->base); |
| 108 | continue; |
| 109 | } |
| 110 | |
| 111 | /* |
| 112 | * Select a buffer that is at least as big as needed |
| 113 | * but not 'too much' bigger. A better way to do this |
| 114 | * might be to bucket the pool objects based on size. |
| 115 | */ |
| 116 | if (tmp->base.size >= size && |
| 117 | tmp->base.size <= (2 * size)) { |
| 118 | obj = tmp; |
| 119 | break; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | if (!obj) { |
| 124 | obj = i915_gem_alloc_object(pool->dev, size); |
| 125 | if (!obj) |
| 126 | return ERR_PTR(-ENOMEM); |
| 127 | |
| 128 | list_add_tail(&obj->batch_pool_list, &pool->cache_list); |
| 129 | } |
| 130 | else |
| 131 | /* Keep list in LRU order */ |
| 132 | list_move_tail(&obj->batch_pool_list, &pool->cache_list); |
| 133 | |
Brad Volkin | 0079a7d | 2014-12-11 12:13:11 -0800 | [diff] [blame] | 134 | obj->madv = I915_MADV_WILLNEED; |
| 135 | |
Brad Volkin | 493018d | 2014-12-11 12:13:08 -0800 | [diff] [blame] | 136 | return obj; |
| 137 | } |