File: | dev/pci/drm/i915/gt/intel_gt_buffer_pool.c |
Warning: | line 245, column 31 Value stored to 'pool' during its initialization is never read |
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1 | // SPDX-License-Identifier: MIT |
2 | /* |
3 | * Copyright © 2014-2018 Intel Corporation |
4 | */ |
5 | |
6 | #include "gem/i915_gem_object.h" |
7 | |
8 | #include "i915_drv.h" |
9 | #include "intel_engine_pm.h" |
10 | #include "intel_gt_buffer_pool.h" |
11 | |
12 | static struct intel_gt *to_gt(struct intel_gt_buffer_pool *pool) |
13 | { |
14 | return container_of(pool, struct intel_gt, buffer_pool)({ const __typeof( ((struct intel_gt *)0)->buffer_pool ) * __mptr = (pool); (struct intel_gt *)( (char *)__mptr - __builtin_offsetof (struct intel_gt, buffer_pool) );}); |
15 | } |
16 | |
17 | static struct list_head * |
18 | bucket_for_size(struct intel_gt_buffer_pool *pool, size_t sz) |
19 | { |
20 | int n; |
21 | |
22 | /* |
23 | * Compute a power-of-two bucket, but throw everything greater than |
24 | * 16KiB into the same bucket: i.e. the buckets hold objects of |
25 | * (1 page, 2 pages, 4 pages, 8+ pages). |
26 | */ |
27 | n = fls(sz >> PAGE_SHIFT12) - 1; |
28 | if (n >= ARRAY_SIZE(pool->cache_list)(sizeof((pool->cache_list)) / sizeof((pool->cache_list) [0]))) |
29 | n = ARRAY_SIZE(pool->cache_list)(sizeof((pool->cache_list)) / sizeof((pool->cache_list) [0])) - 1; |
30 | |
31 | return &pool->cache_list[n]; |
32 | } |
33 | |
34 | static void node_free(struct intel_gt_buffer_pool_node *node) |
35 | { |
36 | i915_gem_object_put(node->obj); |
37 | i915_active_fini(&node->active); |
38 | kfree_rcu(node, rcu)do { free((void *)node, 145, 0); } while(0); |
39 | } |
40 | |
41 | static bool_Bool pool_free_older_than(struct intel_gt_buffer_pool *pool, long keep) |
42 | { |
43 | struct intel_gt_buffer_pool_node *node, *stale = NULL((void *)0); |
44 | bool_Bool active = false0; |
45 | int n; |
46 | |
47 | /* Free buffers that have not been used in the past second */ |
48 | for (n = 0; n < ARRAY_SIZE(pool->cache_list)(sizeof((pool->cache_list)) / sizeof((pool->cache_list) [0])); n++) { |
49 | struct list_head *list = &pool->cache_list[n]; |
50 | |
51 | if (list_empty(list)) |
52 | continue; |
53 | |
54 | if (spin_trylock_irq(&pool->lock)mtx_enter_try(&pool->lock)) { |
55 | struct list_head *pos; |
56 | |
57 | /* Most recent at head; oldest at tail */ |
58 | list_for_each_prev(pos, list)for (pos = (list)->prev; pos != (list); pos = pos->prev ) { |
59 | unsigned long age; |
60 | |
61 | node = list_entry(pos, typeof(*node), link)({ const __typeof( ((typeof(*node) *)0)->link ) *__mptr = ( pos); (typeof(*node) *)( (char *)__mptr - __builtin_offsetof( typeof(*node), link) );}); |
62 | |
63 | age = READ_ONCE(node->age)({ typeof(node->age) __tmp = *(volatile typeof(node->age ) *)&(node->age); membar_datadep_consumer(); __tmp; }); |
64 | if (!age || jiffies - age < keep) |
65 | break; |
66 | |
67 | /* Check we are the first to claim this node */ |
68 | if (!xchg(&node->age, 0)__sync_lock_test_and_set(&node->age, 0)) |
69 | break; |
70 | |
71 | node->free = stale; |
72 | stale = node; |
73 | } |
74 | if (!list_is_last(pos, list)) |
75 | __list_del_many(pos, list); |
76 | |
77 | spin_unlock_irq(&pool->lock)mtx_leave(&pool->lock); |
78 | } |
79 | |
80 | active |= !list_empty(list); |
81 | } |
82 | |
83 | while ((node = stale)) { |
84 | stale = stale->free; |
85 | node_free(node); |
86 | } |
87 | |
88 | return active; |
89 | } |
90 | |
91 | static void pool_free_work(struct work_struct *wrk) |
92 | { |
93 | struct intel_gt_buffer_pool *pool = |
94 | container_of(wrk, typeof(*pool), work.work)({ const __typeof( ((typeof(*pool) *)0)->work.work ) *__mptr = (wrk); (typeof(*pool) *)( (char *)__mptr - __builtin_offsetof (typeof(*pool), work.work) );}); |
95 | |
96 | if (pool_free_older_than(pool, HZhz)) |
97 | schedule_delayed_work(&pool->work, |
98 | round_jiffies_up_relative(HZhz)); |
99 | } |
100 | |
101 | static int pool_active(struct i915_active *ref) |
102 | { |
103 | struct intel_gt_buffer_pool_node *node = |
104 | container_of(ref, typeof(*node), active)({ const __typeof( ((typeof(*node) *)0)->active ) *__mptr = (ref); (typeof(*node) *)( (char *)__mptr - __builtin_offsetof (typeof(*node), active) );}); |
105 | struct dma_resv *resv = node->obj->base.resv; |
106 | int err; |
107 | |
108 | if (dma_resv_trylock(resv)) { |
109 | dma_resv_add_excl_fence(resv, NULL((void *)0)); |
110 | dma_resv_unlock(resv); |
111 | } |
112 | |
113 | err = i915_gem_object_pin_pages(node->obj); |
114 | if (err) |
115 | return err; |
116 | |
117 | /* Hide this pinned object from the shrinker until retired */ |
118 | i915_gem_object_make_unshrinkable(node->obj); |
119 | |
120 | return 0; |
121 | } |
122 | |
123 | __i915_active_call__attribute__((__aligned__(4))) |
124 | static void pool_retire(struct i915_active *ref) |
125 | { |
126 | struct intel_gt_buffer_pool_node *node = |
127 | container_of(ref, typeof(*node), active)({ const __typeof( ((typeof(*node) *)0)->active ) *__mptr = (ref); (typeof(*node) *)( (char *)__mptr - __builtin_offsetof (typeof(*node), active) );}); |
128 | struct intel_gt_buffer_pool *pool = node->pool; |
129 | struct list_head *list = bucket_for_size(pool, node->obj->base.size); |
130 | unsigned long flags; |
131 | |
132 | i915_gem_object_unpin_pages(node->obj); |
133 | |
134 | /* Return this object to the shrinker pool */ |
135 | i915_gem_object_make_purgeable(node->obj); |
136 | |
137 | GEM_BUG_ON(node->age)((void)0); |
138 | spin_lock_irqsave(&pool->lock, flags)do { flags = 0; mtx_enter(&pool->lock); } while (0); |
139 | list_add_rcu(&node->link, list)list_add(&node->link, list); |
140 | WRITE_ONCE(node->age, jiffies ?: 1)({ typeof(node->age) __tmp = (jiffies ?: 1); *(volatile typeof (node->age) *)&(node->age) = __tmp; __tmp; }); /* 0 reserved for active nodes */ |
141 | spin_unlock_irqrestore(&pool->lock, flags)do { (void)(flags); mtx_leave(&pool->lock); } while (0 ); |
142 | |
143 | schedule_delayed_work(&pool->work, |
144 | round_jiffies_up_relative(HZhz)); |
145 | } |
146 | |
147 | static struct intel_gt_buffer_pool_node * |
148 | node_create(struct intel_gt_buffer_pool *pool, size_t sz) |
149 | { |
150 | struct intel_gt *gt = to_gt(pool); |
151 | struct intel_gt_buffer_pool_node *node; |
152 | struct drm_i915_gem_object *obj; |
153 | |
154 | node = kmalloc(sizeof(*node), |
155 | GFP_KERNEL(0x0001 | 0x0004) | __GFP_RETRY_MAYFAIL0 | __GFP_NOWARN0); |
156 | if (!node) |
157 | return ERR_PTR(-ENOMEM12); |
158 | |
159 | node->age = 0; |
160 | node->pool = pool; |
161 | i915_active_init(&node->active, pool_active, pool_retire)do { static struct lock_class_key __mkey; static struct lock_class_key __wkey; __i915_active_init(&node->active, pool_active , pool_retire, &__mkey, &__wkey); } while (0); |
162 | |
163 | obj = i915_gem_object_create_internal(gt->i915, sz); |
164 | if (IS_ERR(obj)) { |
165 | i915_active_fini(&node->active); |
166 | kfree(node); |
167 | return ERR_CAST(obj); |
168 | } |
169 | |
170 | i915_gem_object_set_readonly(obj); |
171 | |
172 | node->obj = obj; |
173 | return node; |
174 | } |
175 | |
176 | struct intel_gt_buffer_pool_node * |
177 | intel_gt_get_buffer_pool(struct intel_gt *gt, size_t size) |
178 | { |
179 | struct intel_gt_buffer_pool *pool = >->buffer_pool; |
180 | struct intel_gt_buffer_pool_node *node; |
181 | struct list_head *list; |
182 | int ret; |
183 | |
184 | size = PAGE_ALIGN(size)(((size) + ((1 << 12) - 1)) & ~((1 << 12) - 1 )); |
185 | list = bucket_for_size(pool, size); |
186 | |
187 | rcu_read_lock(); |
188 | list_for_each_entry_rcu(node, list, link)for (node = ({ const __typeof( ((__typeof(*node) *)0)->link ) *__mptr = ((list)->next); (__typeof(*node) *)( (char *) __mptr - __builtin_offsetof(__typeof(*node), link) );}); & node->link != (list); node = ({ const __typeof( ((__typeof (*node) *)0)->link ) *__mptr = (node->link.next); (__typeof (*node) *)( (char *)__mptr - __builtin_offsetof(__typeof(*node ), link) );})) { |
189 | unsigned long age; |
190 | |
191 | if (node->obj->base.size < size) |
192 | continue; |
193 | |
194 | age = READ_ONCE(node->age)({ typeof(node->age) __tmp = *(volatile typeof(node->age ) *)&(node->age); membar_datadep_consumer(); __tmp; }); |
195 | if (!age) |
196 | continue; |
197 | |
198 | if (cmpxchg(&node->age, age, 0)__sync_val_compare_and_swap(&node->age, age, 0) == age) { |
199 | spin_lock_irq(&pool->lock)mtx_enter(&pool->lock); |
200 | list_del_rcu(&node->link)list_del(&node->link); |
201 | spin_unlock_irq(&pool->lock)mtx_leave(&pool->lock); |
202 | break; |
203 | } |
204 | } |
205 | rcu_read_unlock(); |
206 | |
207 | if (&node->link == list) { |
208 | node = node_create(pool, size); |
209 | if (IS_ERR(node)) |
210 | return node; |
211 | } |
212 | |
213 | ret = i915_active_acquire(&node->active); |
214 | if (ret) { |
215 | node_free(node); |
216 | return ERR_PTR(ret); |
217 | } |
218 | |
219 | return node; |
220 | } |
221 | |
222 | void intel_gt_init_buffer_pool(struct intel_gt *gt) |
223 | { |
224 | struct intel_gt_buffer_pool *pool = >->buffer_pool; |
225 | int n; |
226 | |
227 | mtx_init(&pool->lock, IPL_TTY)do { (void)(((void *)0)); (void)(0); __mtx_init((&pool-> lock), ((((0x9)) > 0x0 && ((0x9)) < 0x9) ? 0x9 : ((0x9)))); } while (0); |
228 | for (n = 0; n < ARRAY_SIZE(pool->cache_list)(sizeof((pool->cache_list)) / sizeof((pool->cache_list) [0])); n++) |
229 | INIT_LIST_HEAD(&pool->cache_list[n]); |
230 | INIT_DELAYED_WORK(&pool->work, pool_free_work); |
231 | } |
232 | |
233 | void intel_gt_flush_buffer_pool(struct intel_gt *gt) |
234 | { |
235 | struct intel_gt_buffer_pool *pool = >->buffer_pool; |
236 | |
237 | do { |
238 | while (pool_free_older_than(pool, 0)) |
239 | ; |
240 | } while (cancel_delayed_work_sync(&pool->work)); |
241 | } |
242 | |
243 | void intel_gt_fini_buffer_pool(struct intel_gt *gt) |
244 | { |
245 | struct intel_gt_buffer_pool *pool = >->buffer_pool; |
Value stored to 'pool' during its initialization is never read | |
246 | int n; |
247 | |
248 | intel_gt_flush_buffer_pool(gt); |
249 | |
250 | for (n = 0; n < ARRAY_SIZE(pool->cache_list)(sizeof((pool->cache_list)) / sizeof((pool->cache_list) [0])); n++) |
251 | GEM_BUG_ON(!list_empty(&pool->cache_list[n]))((void)0); |
252 | } |