Lingfeng Yang | 1cbd16b | 2017-01-31 23:28:39 -0800 | [diff] [blame] | 1 | #include <linux/slab.h> |
| 2 | #include <linux/fs.h> |
| 3 | #include <linux/syscalls.h> |
| 4 | #include <linux/sync_file.h> |
| 5 | #include <linux/fence.h> |
| 6 | |
| 7 | #include "goldfish_sync_timeline_fence.h" |
| 8 | |
| 9 | /* |
| 10 | * Timeline-based sync for Goldfish Sync |
| 11 | * Based on "Sync File validation framework" |
| 12 | * (drivers/dma-buf/sw_sync.c) |
| 13 | * |
| 14 | * Copyright (C) 2017 Google, Inc. |
| 15 | * |
| 16 | * This software is licensed under the terms of the GNU General Public |
| 17 | * License version 2, as published by the Free Software Foundation, and |
| 18 | * may be copied, distributed, and modified under those terms. |
| 19 | * |
| 20 | * This program is distributed in the hope that it will be useful, |
| 21 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 23 | * GNU General Public License for more details. |
| 24 | * |
| 25 | */ |
| 26 | |
| 27 | /** |
| 28 | * struct goldfish_sync_timeline - sync object |
| 29 | * @kref: reference count on fence. |
| 30 | * @name: name of the goldfish_sync_timeline. Useful for debugging |
| 31 | * @child_list_head: list of children sync_pts for this goldfish_sync_timeline |
| 32 | * @child_list_lock: lock protecting @child_list_head and fence.status |
| 33 | * @active_list_head: list of active (unsignaled/errored) sync_pts |
| 34 | */ |
| 35 | struct goldfish_sync_timeline { |
| 36 | struct kref kref; |
| 37 | char name[32]; |
| 38 | |
| 39 | /* protected by child_list_lock */ |
| 40 | u64 context; |
| 41 | int value; |
| 42 | |
| 43 | struct list_head child_list_head; |
| 44 | spinlock_t child_list_lock; |
| 45 | |
| 46 | struct list_head active_list_head; |
| 47 | }; |
| 48 | |
| 49 | static inline struct goldfish_sync_timeline *fence_parent(struct fence *fence) |
| 50 | { |
| 51 | return container_of(fence->lock, struct goldfish_sync_timeline, |
| 52 | child_list_lock); |
| 53 | } |
| 54 | |
| 55 | static const struct fence_ops goldfish_sync_timeline_fence_ops; |
| 56 | |
| 57 | static inline struct sync_pt *goldfish_sync_fence_to_sync_pt(struct fence *fence) |
| 58 | { |
| 59 | if (fence->ops != &goldfish_sync_timeline_fence_ops) |
| 60 | return NULL; |
| 61 | return container_of(fence, struct sync_pt, base); |
| 62 | } |
| 63 | |
| 64 | /** |
| 65 | * goldfish_sync_timeline_create_internal() - creates a sync object |
| 66 | * @name: sync_timeline name |
| 67 | * |
| 68 | * Creates a new sync_timeline. Returns the sync_timeline object or NULL in |
| 69 | * case of error. |
| 70 | */ |
| 71 | struct goldfish_sync_timeline |
| 72 | *goldfish_sync_timeline_create_internal(const char *name) |
| 73 | { |
| 74 | struct goldfish_sync_timeline *obj; |
| 75 | |
| 76 | obj = kzalloc(sizeof(*obj), GFP_KERNEL); |
| 77 | if (!obj) |
| 78 | return NULL; |
| 79 | |
| 80 | kref_init(&obj->kref); |
| 81 | obj->context = fence_context_alloc(1); |
| 82 | strlcpy(obj->name, name, sizeof(obj->name)); |
| 83 | |
| 84 | INIT_LIST_HEAD(&obj->child_list_head); |
| 85 | INIT_LIST_HEAD(&obj->active_list_head); |
| 86 | spin_lock_init(&obj->child_list_lock); |
| 87 | |
| 88 | return obj; |
| 89 | } |
| 90 | |
| 91 | static void goldfish_sync_timeline_free_internal(struct kref *kref) |
| 92 | { |
| 93 | struct goldfish_sync_timeline *obj = |
| 94 | container_of(kref, struct goldfish_sync_timeline, kref); |
| 95 | |
| 96 | kfree(obj); |
| 97 | } |
| 98 | |
| 99 | static void goldfish_sync_timeline_get_internal( |
| 100 | struct goldfish_sync_timeline *obj) |
| 101 | { |
| 102 | kref_get(&obj->kref); |
| 103 | } |
| 104 | |
| 105 | void goldfish_sync_timeline_put_internal(struct goldfish_sync_timeline *obj) |
| 106 | { |
| 107 | kref_put(&obj->kref, goldfish_sync_timeline_free_internal); |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * goldfish_sync_timeline_signal() - |
| 112 | * signal a status change on a goldfish_sync_timeline |
| 113 | * @obj: sync_timeline to signal |
| 114 | * @inc: num to increment on timeline->value |
| 115 | * |
| 116 | * A sync implementation should call this any time one of it's fences |
| 117 | * has signaled or has an error condition. |
| 118 | */ |
| 119 | void goldfish_sync_timeline_signal_internal(struct goldfish_sync_timeline *obj, |
| 120 | unsigned int inc) |
| 121 | { |
| 122 | unsigned long flags; |
| 123 | struct sync_pt *pt, *next; |
| 124 | |
| 125 | spin_lock_irqsave(&obj->child_list_lock, flags); |
| 126 | |
| 127 | obj->value += inc; |
| 128 | |
| 129 | list_for_each_entry_safe(pt, next, &obj->active_list_head, |
| 130 | active_list) { |
| 131 | if (fence_is_signaled_locked(&pt->base)) |
| 132 | list_del_init(&pt->active_list); |
| 133 | } |
| 134 | |
| 135 | spin_unlock_irqrestore(&obj->child_list_lock, flags); |
| 136 | } |
| 137 | |
| 138 | /** |
| 139 | * goldfish_sync_pt_create_internal() - creates a sync pt |
| 140 | * @parent: fence's parent sync_timeline |
| 141 | * @size: size to allocate for this pt |
| 142 | * @inc: value of the fence |
| 143 | * |
| 144 | * Creates a new sync_pt as a child of @parent. @size bytes will be |
| 145 | * allocated allowing for implementation specific data to be kept after |
| 146 | * the generic sync_timeline struct. Returns the sync_pt object or |
| 147 | * NULL in case of error. |
| 148 | */ |
| 149 | struct sync_pt *goldfish_sync_pt_create_internal( |
| 150 | struct goldfish_sync_timeline *obj, int size, |
| 151 | unsigned int value) |
| 152 | { |
| 153 | unsigned long flags; |
| 154 | struct sync_pt *pt; |
| 155 | |
| 156 | if (size < sizeof(*pt)) |
| 157 | return NULL; |
| 158 | |
| 159 | pt = kzalloc(size, GFP_KERNEL); |
| 160 | if (!pt) |
| 161 | return NULL; |
| 162 | |
| 163 | spin_lock_irqsave(&obj->child_list_lock, flags); |
| 164 | goldfish_sync_timeline_get_internal(obj); |
| 165 | fence_init(&pt->base, &goldfish_sync_timeline_fence_ops, &obj->child_list_lock, |
| 166 | obj->context, value); |
| 167 | list_add_tail(&pt->child_list, &obj->child_list_head); |
| 168 | INIT_LIST_HEAD(&pt->active_list); |
| 169 | spin_unlock_irqrestore(&obj->child_list_lock, flags); |
| 170 | return pt; |
| 171 | } |
| 172 | |
| 173 | static const char *goldfish_sync_timeline_fence_get_driver_name( |
| 174 | struct fence *fence) |
| 175 | { |
| 176 | return "sw_sync"; |
| 177 | } |
| 178 | |
| 179 | static const char *goldfish_sync_timeline_fence_get_timeline_name( |
| 180 | struct fence *fence) |
| 181 | { |
| 182 | struct goldfish_sync_timeline *parent = fence_parent(fence); |
| 183 | |
| 184 | return parent->name; |
| 185 | } |
| 186 | |
| 187 | static void goldfish_sync_timeline_fence_release(struct fence *fence) |
| 188 | { |
| 189 | struct sync_pt *pt = goldfish_sync_fence_to_sync_pt(fence); |
| 190 | struct goldfish_sync_timeline *parent = fence_parent(fence); |
| 191 | unsigned long flags; |
| 192 | |
| 193 | spin_lock_irqsave(fence->lock, flags); |
| 194 | list_del(&pt->child_list); |
| 195 | if (!list_empty(&pt->active_list)) |
| 196 | list_del(&pt->active_list); |
| 197 | spin_unlock_irqrestore(fence->lock, flags); |
| 198 | |
| 199 | goldfish_sync_timeline_put_internal(parent); |
| 200 | fence_free(fence); |
| 201 | } |
| 202 | |
| 203 | static bool goldfish_sync_timeline_fence_signaled(struct fence *fence) |
| 204 | { |
| 205 | struct goldfish_sync_timeline *parent = fence_parent(fence); |
| 206 | |
| 207 | return (fence->seqno > parent->value) ? false : true; |
| 208 | } |
| 209 | |
| 210 | static bool goldfish_sync_timeline_fence_enable_signaling(struct fence *fence) |
| 211 | { |
| 212 | struct sync_pt *pt = goldfish_sync_fence_to_sync_pt(fence); |
| 213 | struct goldfish_sync_timeline *parent = fence_parent(fence); |
| 214 | |
| 215 | if (goldfish_sync_timeline_fence_signaled(fence)) |
| 216 | return false; |
| 217 | |
| 218 | list_add_tail(&pt->active_list, &parent->active_list_head); |
| 219 | return true; |
| 220 | } |
| 221 | |
| 222 | static void goldfish_sync_timeline_fence_disable_signaling(struct fence *fence) |
| 223 | { |
| 224 | struct sync_pt *pt = container_of(fence, struct sync_pt, base); |
| 225 | |
| 226 | list_del_init(&pt->active_list); |
| 227 | } |
| 228 | |
| 229 | static void goldfish_sync_timeline_fence_value_str(struct fence *fence, |
| 230 | char *str, int size) |
| 231 | { |
| 232 | snprintf(str, size, "%d", fence->seqno); |
| 233 | } |
| 234 | |
| 235 | static void goldfish_sync_timeline_fence_timeline_value_str( |
| 236 | struct fence *fence, |
| 237 | char *str, int size) |
| 238 | { |
| 239 | struct goldfish_sync_timeline *parent = fence_parent(fence); |
| 240 | |
| 241 | snprintf(str, size, "%d", parent->value); |
| 242 | } |
| 243 | |
| 244 | static const struct fence_ops goldfish_sync_timeline_fence_ops = { |
| 245 | .get_driver_name = goldfish_sync_timeline_fence_get_driver_name, |
| 246 | .get_timeline_name = goldfish_sync_timeline_fence_get_timeline_name, |
| 247 | .enable_signaling = goldfish_sync_timeline_fence_enable_signaling, |
| 248 | .disable_signaling = goldfish_sync_timeline_fence_disable_signaling, |
| 249 | .signaled = goldfish_sync_timeline_fence_signaled, |
| 250 | .wait = fence_default_wait, |
| 251 | .release = goldfish_sync_timeline_fence_release, |
| 252 | .fence_value_str = goldfish_sync_timeline_fence_value_str, |
| 253 | .timeline_value_str = goldfish_sync_timeline_fence_timeline_value_str, |
| 254 | }; |