1 /*
2  *  ion.c
3  *
4  * Memory Allocator functions for ion
5  *
6  *   Copyright 2011 Google, Inc
7  *
8  *  Licensed under the Apache License, Version 2.0 (the "License");
9  *  you may not use this file except in compliance with the License.
10  *  You may obtain a copy of the License at
11  *
12  *      http://www.apache.org/licenses/LICENSE-2.0
13  *
14  *  Unless required by applicable law or agreed to in writing, software
15  *  distributed under the License is distributed on an "AS IS" BASIS,
16  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  *  See the License for the specific language governing permissions and
18  *  limitations under the License.
19  */
20 #define LOG_TAG "ion"
21 
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <linux/ion.h>
25 #include <stdatomic.h>
26 #include <stdio.h>
27 #include <string.h>
28 #include <sys/ioctl.h>
29 #include <sys/mman.h>
30 #include <sys/types.h>
31 #include <unistd.h>
32 
33 #include <ion/ion.h>
34 #include <linux/ion_4.19.h>
35 
36 #include <log/log.h>
37 
38 #define ION_ABI_VERSION_MODULAR_HEAPS 2
39 
40 enum ion_version { ION_VERSION_UNKNOWN, ION_VERSION_MODERN, ION_VERSION_LEGACY };
41 
42 static atomic_int g_ion_version = ATOMIC_VAR_INIT(ION_VERSION_UNKNOWN);
43 
44 int ion_is_legacy(int fd) {
45     int version = atomic_load_explicit(&g_ion_version, memory_order_acquire);
46     if (version == ION_VERSION_UNKNOWN) {
47         /**
48           * Check for FREE IOCTL here; it is available only in the old
49           * kernels, not the new ones.
50           */
51         int err = ion_free(fd, (ion_user_handle_t)NULL);
52         version = (err == -ENOTTY) ? ION_VERSION_MODERN : ION_VERSION_LEGACY;
53         atomic_store_explicit(&g_ion_version, version, memory_order_release);
54     }
55     return version == ION_VERSION_LEGACY;
56 }
57 
58 int ion_open() {
59     int fd = open("/dev/ion", O_RDONLY | O_CLOEXEC);
60     if (fd < 0) ALOGE("open /dev/ion failed: %s", strerror(errno));
61 
62     return fd;
63 }
64 
65 int ion_close(int fd) {
66     int ret = close(fd);
67     if (ret < 0) return -errno;
68     return ret;
69 }
70 
71 static int ion_ioctl(int fd, int req, void* arg) {
72     int ret = ioctl(fd, req, arg);
73     if (ret < 0) {
74         ALOGE("ioctl %x failed with code %d: %s", req, ret, strerror(errno));
75         return -errno;
76     }
77     return ret;
78 }
79 
80 int ion_is_using_modular_heaps(int fd) {
81     int ion_abi_version = 0;
82     int ret = 0;
83 
84     ret = ion_ioctl(fd, ION_IOC_ABI_VERSION, &ion_abi_version);
85     return (ret == 0 && ion_abi_version >= ION_ABI_VERSION_MODULAR_HEAPS);
86 }
87 
88 int ion_alloc(int fd, size_t len, size_t align, unsigned int heap_mask, unsigned int flags,
89               ion_user_handle_t* handle) {
90     int ret = 0;
91 
92     if ((handle == NULL) || (!ion_is_legacy(fd))) return -EINVAL;
93 
94     struct ion_allocation_data data = {
95         .len = len, .align = align, .heap_id_mask = heap_mask, .flags = flags,
96     };
97 
98     ret = ion_ioctl(fd, ION_IOC_ALLOC, &data);
99     if (ret < 0) return ret;
100 
101     *handle = data.handle;
102 
103     return ret;
104 }
105 
106 int ion_free(int fd, ion_user_handle_t handle) {
107     struct ion_handle_data data = {
108         .handle = handle,
109     };
110     return ion_ioctl(fd, ION_IOC_FREE, &data);
111 }
112 
113 int ion_map(int fd, ion_user_handle_t handle, size_t length, int prot, int flags, off_t offset,
114             unsigned char** ptr, int* map_fd) {
115     if (!ion_is_legacy(fd)) return -EINVAL;
116     int ret;
117     unsigned char* tmp_ptr;
118     struct ion_fd_data data = {
119         .handle = handle,
120     };
121 
122     if (map_fd == NULL) return -EINVAL;
123     if (ptr == NULL) return -EINVAL;
124 
125     ret = ion_ioctl(fd, ION_IOC_MAP, &data);
126     if (ret < 0) return ret;
127     if (data.fd < 0) {
128         ALOGE("map ioctl returned negative fd");
129         return -EINVAL;
130     }
131     tmp_ptr = mmap(NULL, length, prot, flags, data.fd, offset);
132     if (tmp_ptr == MAP_FAILED) {
133         ALOGE("mmap failed: %s", strerror(errno));
134         return -errno;
135     }
136     *map_fd = data.fd;
137     *ptr = tmp_ptr;
138     return ret;
139 }
140 
141 int ion_share(int fd, ion_user_handle_t handle, int* share_fd) {
142     int ret;
143     struct ion_fd_data data = {
144         .handle = handle,
145     };
146 
147     if (!ion_is_legacy(fd)) return -EINVAL;
148     if (share_fd == NULL) return -EINVAL;
149 
150     ret = ion_ioctl(fd, ION_IOC_SHARE, &data);
151     if (ret < 0) return ret;
152     if (data.fd < 0) {
153         ALOGE("share ioctl returned negative fd");
154         return -EINVAL;
155     }
156     *share_fd = data.fd;
157     return ret;
158 }
159 
160 int ion_alloc_fd(int fd, size_t len, size_t align, unsigned int heap_mask, unsigned int flags,
161                  int* handle_fd) {
162     ion_user_handle_t handle;
163     int ret;
164 
165     if (!handle_fd) return -EINVAL;
166 
167     if (!ion_is_legacy(fd)) {
168         struct ion_new_allocation_data data = {
169             .len = len,
170             .heap_id_mask = heap_mask,
171             .flags = flags,
172         };
173 
174         ret = ion_ioctl(fd, ION_IOC_NEW_ALLOC, &data);
175         if (ret < 0) return ret;
176         *handle_fd = data.fd;
177     } else {
178         ret = ion_alloc(fd, len, align, heap_mask, flags, &handle);
179         if (ret < 0) return ret;
180         ret = ion_share(fd, handle, handle_fd);
181         ion_free(fd, handle);
182     }
183     return ret;
184 }
185 
186 int ion_import(int fd, int share_fd, ion_user_handle_t* handle) {
187     int ret;
188     struct ion_fd_data data = {
189         .fd = share_fd,
190     };
191 
192     if (!ion_is_legacy(fd)) return -EINVAL;
193 
194     if (handle == NULL) return -EINVAL;
195 
196     ret = ion_ioctl(fd, ION_IOC_IMPORT, &data);
197     if (ret < 0) return ret;
198     *handle = data.handle;
199     return ret;
200 }
201 
202 int ion_sync_fd(int fd, int handle_fd) {
203     struct ion_fd_data data = {
204         .fd = handle_fd,
205     };
206 
207     if (!ion_is_legacy(fd)) return -EINVAL;
208 
209     return ion_ioctl(fd, ION_IOC_SYNC, &data);
210 }
211 
212 int ion_query_heap_cnt(int fd, int* cnt) {
213     int ret;
214     struct ion_heap_query query;
215 
216     if (!cnt) return -EINVAL;
217     memset(&query, 0, sizeof(query));
218 
219     ret = ion_ioctl(fd, ION_IOC_HEAP_QUERY, &query);
220     if (ret < 0) return ret;
221 
222     *cnt = query.cnt;
223     return ret;
224 }
225 
226 int ion_query_get_heaps(int fd, int cnt, void* buffers) {
227     int ret;
228     struct ion_heap_query query = {
229         .cnt = cnt, .heaps = (uintptr_t)buffers,
230     };
231 
232     ret = ion_ioctl(fd, ION_IOC_HEAP_QUERY, &query);
233     return ret;
234 }
235