xref: /openbmc/hiomapd/file/backend.c (revision a042978b)
1 // SPDX-License-Identifier: Apache-2.0
2 // Copyright (C) 2018 IBM Corp.
3 // Copyright (C) 2018 Evan Lojewski.
4 
5 #define _GNU_SOURCE
6 #include <assert.h>
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <getopt.h>
10 #include <inttypes.h>
11 #include <limits.h>
12 #include <mtd/mtd-abi.h>
13 #include <poll.h>
14 #include <signal.h>
15 #include <stdbool.h>
16 #include <stdint.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <string.h>
20 #include <sys/ioctl.h>
21 #include <sys/mman.h>
22 #include <sys/stat.h>
23 #include <sys/timerfd.h>
24 #include <sys/types.h>
25 #include <syslog.h>
26 #include <time.h>
27 #include <unistd.h>
28 
29 #include "common.h"
30 #include "backend.h"
31 #include "lpc.h"
32 #include "mboxd.h"
33 
34 #define MIN(__x__, __y__)  (((__x__) < (__y__)) ? (__x__) : (__y__))
35 
36 #define FILE_ERASE_SIZE (4 * 1024)
37 
38 struct file_data {
39 	int fd;
40 };
41 
42 static int file_dev_init(struct backend *backend, void *data)
43 {
44 	struct mtd_info_user info;
45 	const char *path = data;
46 	struct file_data *priv;
47 	struct stat statbuf;
48 	int rc = 0;
49 
50 	if (!path) {
51 		MSG_ERR("No PNOR file specified\n");
52 		return -EINVAL;
53 	}
54 
55 	priv = malloc(sizeof(*priv));
56 	if (!priv)
57 		return -errno;
58 
59 	MSG_DBG("Opening %s\n", path);
60 
61 	priv->fd = open(path, O_RDWR);
62 	if (priv->fd < 0) {
63 		MSG_ERR("Couldn't open %s with flags O_RDWR: %s\n", path,
64 			strerror(errno));
65 		rc = -errno;
66 		goto cleanup_data;
67 	}
68 
69 	/* Don't attach to mtd devices. */
70 	rc = ioctl(priv->fd, MEMGETINFO, &info);
71 	if (rc != -1) {
72 		rc = -errno;
73 		goto cleanup_fd;
74 	}
75 
76 	rc = fstat(priv->fd, &statbuf);
77 	if (rc < 0) {
78 		rc = -errno;
79 		goto cleanup_fd;
80 	}
81 
82 	if (backend->flash_size == 0) {
83 		MSG_INFO("Flash size should be supplied on the commandline.\n");
84 		backend->flash_size = statbuf.st_size;
85 	}
86 
87 	/* Pick an erase size congruent with partition alignment */
88 	backend->erase_size_shift = log_2(FILE_ERASE_SIZE);
89 	backend->block_size_shift = backend->erase_size_shift;
90 	MSG_DBG("Flash erase size: 0x%.8x\n", FILE_ERASE_SIZE);
91 
92 	backend->priv = priv;
93 	return rc;
94 
95 cleanup_fd:
96 	close(priv->fd);
97 cleanup_data:
98 	free(priv);
99 	return rc;
100 }
101 
102 static void file_dev_free(struct backend *backend)
103 {
104 	struct file_data *priv = backend->priv;
105 
106 	close(priv->fd);
107 	free(priv);
108 }
109 
110 /* Flash Functions */
111 
112 /*
113  * file_erase() - Erase the flash
114  * @context:	The mbox context pointer
115  * @offset:	The flash offset to erase (bytes)
116  * @size:	The number of bytes to erase
117  *
118  * Return:	0 on success otherwise negative error code
119  */
120 static int file_erase(struct backend *backend, uint32_t offset, uint32_t count)
121 {
122 	const uint32_t erase_size = 1 << backend->erase_size_shift;
123 	struct file_data *priv = backend->priv;
124 	struct erase_info_user erase_info = {0};
125 	int rc;
126 
127 	MSG_DBG("Erase flash @ 0x%.8x for 0x%.8x\n", offset, count);
128 
129 	uint8_t* erase_buf = (uint8_t*)malloc(count);
130 	if (!erase_buf) {
131 		MSG_ERR("Couldn't malloc erase buffer. %s\n", strerror(errno));
132 		return -1;
133 	}
134 	memset(erase_buf, 0xFF, erase_size);
135 	rc = pwrite(priv->fd, erase_buf, count, offset);
136 	free(erase_buf);
137 
138 	if (rc < 0) {
139 		MSG_ERR("Couldn't erase flash at 0x%.8x\n", erase_info.start);
140 		return -errno;
141 	}
142 
143 
144 	return 0;
145 }
146 
147 #define CHUNKSIZE (64 * 1024)
148 
149 /*
150  * file_copy() - Copy data from the flash device into a provided buffer
151  * @context:	The backend context pointer
152  * @offset:	The flash offset to copy from (bytes)
153  * @mem:	The buffer to copy into (must be of atleast 'size' bytes)
154  * @size:	The number of bytes to copy
155  * Return:	Number of bytes copied on success, otherwise negative error
156  *		code. file_copy will copy at most 'size' bytes, but it may
157  *		copy less.
158  */
159 static int64_t file_copy(struct backend *backend, uint32_t offset,
160 			  void *mem, uint32_t size)
161 {
162 	struct file_data *priv = backend->priv;
163 	int32_t size_read;
164 	void *start = mem;
165 
166 	MSG_DBG("Copy flash to %p for size 0x%.8x from offset 0x%.8x\n", mem,
167 		size, offset);
168 	if (lseek(priv->fd, offset, SEEK_SET) != offset) {
169 		MSG_ERR("Couldn't seek flash at pos: %u %s\n", offset,
170 			strerror(errno));
171 		return -errno;
172 	}
173 
174 	do {
175 		size_read = read(priv->fd, mem, min_u32(CHUNKSIZE, size));
176 		if (size_read < 0) {
177 			MSG_ERR("Couldn't copy file into ram: %s\n",
178 				strerror(errno));
179 			return -errno;
180 		}
181 
182 		size -= size_read;
183 		mem += size_read;
184 	} while (size && size_read);
185 
186 	return size_read ? mem - start : -EIO;
187 }
188 
189 /*
190  * file_write() - Write the flash from a provided buffer
191  * @context:	The mbox context pointer
192  * @offset:	The flash offset to write to (bytes)
193  * @buf:	The buffer to write from (must be of atleast size)
194  * @size:	The number of bytes to write
195  *
196  * Return:	0 on success otherwise negative error code
197  */
198 static int file_write(struct backend *backend, uint32_t offset, void *buf,
199 		       uint32_t count)
200 {
201 	struct file_data *priv = backend->priv;
202 	uint32_t buf_offset = 0;
203 	int rc;
204 
205 	MSG_DBG("Write flash @ 0x%.8x for 0x%.8x from %p\n", offset, count,
206 		buf);
207 
208 	if (lseek(priv->fd, offset, SEEK_SET) != offset) {
209 		MSG_ERR("Couldn't seek flash at pos: %u %s\n", offset,
210 			strerror(errno));
211 		return -errno;
212 	}
213 
214 	while (count) {
215 		rc = write(priv->fd, buf + buf_offset, count);
216 		if (rc < 0) {
217 			MSG_ERR("Couldn't write to file, write lost: %s\n",
218 				strerror(errno));
219 			return -errno;
220 		}
221 		count -= rc;
222 		buf_offset += rc;
223 	}
224 
225 	return 0;
226 }
227 
228 /*
229  * file_reset() - Reset the lpc bus mapping
230  * @context:    The backend context pointer
231  * @buf:	Pointer to the LPC reserved memory
232  * @count:	The size of the LPC reserved memory
233  *
234  * Return:      0 on success otherwise negative error code
235  */
236 static int file_reset(struct backend *backend, void *buf, uint32_t count)
237 {
238 	struct file_data *priv = backend->priv;
239 	size_t len;
240 	int rc;
241 
242 	len = MIN(backend->flash_size, count);
243 
244 	/* Ugh, otherwise we need to parse the FFS image */
245 	assert(len == backend->flash_size);
246 
247 	/* Preload Flash contents into memory window */
248 	rc = pread(priv->fd, buf, len, 0);
249 	if (rc < 0)
250 		return -errno;
251 
252 	return reset_lpc_memory;
253 }
254 
255 static const struct backend_ops file_ops = {
256 	.init = file_dev_init,
257 	.free = file_dev_free,
258 	.copy = file_copy,
259 	.erase = file_erase,
260 	.write = file_write,
261 	.reset = file_reset,
262 	.validate = NULL,
263 };
264 
265 struct backend backend_get_file(void)
266 {
267 	struct backend be = {0};
268 
269 	be.ops = &file_ops;
270 
271 	return be;
272 }
273 
274 int backend_probe_file(struct backend *master, const char *path)
275 {
276 	struct backend with;
277 
278 	assert(master);
279 	with = backend_get_file();
280 
281 	return backend_init(master, &with, (void *)path);
282 }
283