1 /*
2 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
3 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this list of
9 * conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
12 * of conditions and the following disclaimer in the documentation and/or other materials
13 * provided with the distribution.
14 *
15 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
16 * to endorse or promote products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "fcntl.h"
33 #include "linux/kernel.h"
34 #include "fs/driver.h"
35
MemOpen(struct file * filep)36 static int MemOpen(struct file *filep)
37 {
38 return 0;
39 }
40
MemClose(struct file * filep)41 static int MemClose(struct file *filep)
42 {
43 return 0;
44 }
45
MemRead(struct file * filep,char * buffer,size_t buflen)46 static ssize_t MemRead(struct file *filep, char *buffer, size_t buflen)
47 {
48 return 0;
49 }
50
MemWrite(struct file * filep,const char * buffer,size_t buflen)51 static ssize_t MemWrite(struct file *filep, const char *buffer, size_t buflen)
52 {
53 return 0;
54 }
55
MemMap(struct file * filep,LosVmMapRegion * region)56 static ssize_t MemMap(struct file *filep, LosVmMapRegion *region)
57 {
58 #ifdef LOSCFG_KERNEL_VM
59 size_t size = region->range.size;
60 PADDR_T paddr = region->pgOff << PAGE_SHIFT;
61 VADDR_T vaddr = region->range.base;
62 LosVmSpace *space = LOS_SpaceGet(vaddr);
63
64 if ((paddr >= SYS_MEM_BASE) && (paddr < SYS_MEM_END)) {
65 return -EINVAL;
66 }
67
68 /* Peripheral register memory adds strongly ordered attributes */
69 region->regionFlags |= VM_MAP_REGION_FLAG_STRONGLY_ORDERED;
70
71 if (space == NULL) {
72 return -EAGAIN;
73 }
74 if (LOS_ArchMmuMap(&space->archMmu, vaddr, paddr, size >> PAGE_SHIFT, region->regionFlags) <= 0) {
75 return -EAGAIN;
76 }
77 #else
78 UNUSED(filep);
79 UNUSED(region);
80 #endif
81 return 0;
82 }
83
84 static const struct file_operations_vfs g_memDevOps = {
85 MemOpen, /* open */
86 MemClose, /* close */
87 MemRead, /* read */
88 MemWrite, /* write */
89 NULL, /* seek */
90 NULL, /* ioctl */
91 MemMap, /* mmap */
92 #ifndef CONFIG_DISABLE_POLL
93 NULL, /* poll */
94 #endif
95 NULL, /* unlink */
96 };
97
DevMemRegister(void)98 int DevMemRegister(void)
99 {
100 return register_driver("/dev/mem", &g_memDevOps, 0666, 0); /* 0666: file mode */
101 }
102