xref: /openbmc/hiomapd/vpnor/partition.cpp (revision fb01e14e)
1 // SPDX-License-Identifier: Apache-2.0
2 // Copyright (C) 2018 IBM Corp.
3 extern "C" {
4 #include "mboxd.h"
5 }
6 
7 #include "config.h"
8 
9 #include "pnor_partition_table.hpp"
10 #include "vpnor/partition.hpp"
11 #include "xyz/openbmc_project/Common/error.hpp"
12 
13 #include <assert.h>
14 #include <fcntl.h>
15 #include <stdint.h>
16 #include <stdlib.h>
17 #include <sys/ioctl.h>
18 #include <sys/mman.h>
19 #include <sys/types.h>
20 #include <syslog.h>
21 #include <unistd.h>
22 
23 #include <exception>
24 #include <iostream>
25 #include <phosphor-logging/elog-errors.hpp>
26 #include <phosphor-logging/log.hpp>
27 #include <stdexcept>
28 #include <string>
29 
30 #include "common.h"
31 #include "vpnor/backend.h"
32 
33 namespace openpower
34 {
35 namespace virtual_pnor
36 {
37 
38 namespace fs = std::experimental::filesystem;
39 
40 fs::path Request::getPartitionFilePath(int flags)
41 {
42     struct vpnor_data* priv = (struct vpnor_data*)backend->priv;
43 
44     // Check if partition exists in patch location
45     auto dst = fs::path(priv->paths.patch_loc) / partition.data.name;
46     if (fs::is_regular_file(dst))
47     {
48         return dst;
49     }
50 
51     switch (partition.data.user.data[1] &
52             (PARTITION_PRESERVED | PARTITION_READONLY))
53     {
54         case PARTITION_PRESERVED:
55             dst = priv->paths.prsv_loc;
56             break;
57 
58         case PARTITION_READONLY:
59             dst = priv->paths.ro_loc;
60             break;
61 
62         default:
63             dst = priv->paths.rw_loc;
64     }
65     dst /= partition.data.name;
66 
67     if (fs::exists(dst))
68     {
69         return dst;
70     }
71 
72     if (flags == O_RDONLY)
73     {
74         dst = fs::path(priv->paths.ro_loc) / partition.data.name;
75         assert(fs::exists(dst));
76         return dst;
77     }
78 
79     assert(flags == O_RDWR);
80     auto src = fs::path(priv->paths.ro_loc) / partition.data.name;
81     assert(fs::exists(src));
82 
83     MSG_DBG("RWRequest: Didn't find '%s' under '%s', copying from '%s'\n",
84             partition.data.name, dst.c_str(), src.c_str());
85 
86     dst = priv->paths.rw_loc;
87     if (partition.data.user.data[1] & PARTITION_PRESERVED)
88     {
89         dst = priv->paths.prsv_loc;
90     }
91 
92     dst /= partition.data.name;
93     fs::copy_file(src, dst);
94 
95     return dst;
96 }
97 
98 size_t Request::clamp(size_t len)
99 {
100     size_t maxAccess = offset + len;
101     size_t partSize = partition.data.size << backend->block_size_shift;
102     return std::min(maxAccess, partSize) - offset;
103 }
104 
105 void Request::resize(const fs::path& path, size_t len)
106 {
107     size_t maxAccess = offset + len;
108     size_t fileSize = fs::file_size(path);
109     if (maxAccess < fileSize)
110     {
111         return;
112     }
113     MSG_DBG("Resizing %s to %zu bytes\n", path.c_str(), maxAccess);
114     int rc = truncate(path.c_str(), maxAccess);
115     if (rc == -1)
116     {
117         MSG_ERR("Failed to resize %s: %d\n", path.c_str(), errno);
118         throw std::system_error(errno, std::system_category());
119     }
120 }
121 
122 size_t Request::fulfil(const fs::path& path, int flags, void* buf, size_t len)
123 {
124     if (!(flags == O_RDONLY || flags == O_RDWR))
125     {
126         std::stringstream err;
127         err << "Require O_RDONLY (0x" << std::hex << O_RDONLY << " or O_RDWR "
128             << std::hex << O_RDWR << " for flags, got: 0x" << std::hex << flags;
129         throw std::invalid_argument(err.str());
130     }
131 
132     int fd = ::open(path.c_str(), flags);
133     if (fd == -1)
134     {
135         MSG_ERR("Failed to open backing file at '%s': %d\n", path.c_str(),
136                 errno);
137         throw std::system_error(errno, std::system_category());
138     }
139 
140     if (flags == O_RDONLY)
141     {
142         MSG_INFO("Fulfilling read request against %s at offset 0x%zx into %p "
143                  "for %zu\n",
144                  path.c_str(), offset, buf, len);
145     }
146     else
147     {
148         MSG_INFO("Fulfilling write request against %s at offset 0x%zx from %p "
149                  "for %zu\n",
150                  path.c_str(), offset, buf, len);
151     }
152 
153     size_t fileSize = fs::file_size(path);
154     int mprot = PROT_READ | ((flags == O_RDWR) ? PROT_WRITE : 0);
155     auto map = mmap(NULL, fileSize, mprot, MAP_SHARED, fd, 0);
156     if (map == MAP_FAILED)
157     {
158         close(fd);
159         MSG_ERR("Failed to map backing file '%s' for %zd bytes: %d\n",
160                 path.c_str(), fileSize, errno);
161         throw std::system_error(errno, std::system_category());
162     }
163 
164     // copy to the reserved memory area
165     if (flags == O_RDONLY)
166     {
167         memset(buf, 0xff, len);
168         memcpy(buf, (char*)map + offset, std::min(len, fileSize));
169     }
170     else
171     {
172         memcpy((char*)map + offset, buf, len);
173         backend_set_bytemap(backend, base + offset, len, FLASH_DIRTY);
174     }
175     munmap(map, fileSize);
176     close(fd);
177 
178     return len;
179 }
180 
181 } // namespace virtual_pnor
182 } // namespace openpower
183