xref: /openbmc/hiomapd/file/backend.c (revision 68a24c9e)
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 #pragma GCC diagnostic push
39 #pragma GCC diagnostic ignored "-Wpointer-arith"
40 
41 struct file_data {
42 	int fd;
43 };
44 
file_dev_init(struct backend * backend,void * data)45 static int file_dev_init(struct backend *backend, void *data)
46 {
47 	struct mtd_info_user info;
48 	const char *path = data;
49 	struct file_data *priv;
50 	struct stat statbuf;
51 	int rc = 0;
52 
53 	if (!path) {
54 		MSG_ERR("No PNOR file specified\n");
55 		return -EINVAL;
56 	}
57 
58 	priv = malloc(sizeof(*priv));
59 	if (!priv)
60 		return -errno;
61 
62 	MSG_DBG("Opening %s\n", path);
63 
64 	priv->fd = open(path, O_RDWR);
65 	if (priv->fd < 0) {
66 		MSG_ERR("Couldn't open %s with flags O_RDWR: %s\n", path,
67 			strerror(errno));
68 		rc = -errno;
69 		goto cleanup_data;
70 	}
71 
72 	/* Don't attach to mtd devices. */
73 	rc = ioctl(priv->fd, MEMGETINFO, &info);
74 	if (rc != -1) {
75 		rc = -errno;
76 		goto cleanup_fd;
77 	}
78 
79 	rc = fstat(priv->fd, &statbuf);
80 	if (rc < 0) {
81 		rc = -errno;
82 		goto cleanup_fd;
83 	}
84 
85 	if (backend->flash_size == 0) {
86 		MSG_INFO("Flash size should be supplied on the commandline.\n");
87 		backend->flash_size = statbuf.st_size;
88 	}
89 
90 	/* Pick an erase size congruent with partition alignment */
91 	backend->erase_size_shift = log_2(FILE_ERASE_SIZE);
92 	backend->block_size_shift = backend->erase_size_shift;
93 	MSG_DBG("Flash erase size: 0x%.8x\n", FILE_ERASE_SIZE);
94 
95 	backend->priv = priv;
96 	return rc;
97 
98 cleanup_fd:
99 	close(priv->fd);
100 cleanup_data:
101 	free(priv);
102 	return rc;
103 }
104 
file_dev_free(struct backend * backend)105 static void file_dev_free(struct backend *backend)
106 {
107 	struct file_data *priv = backend->priv;
108 
109 	close(priv->fd);
110 	free(priv);
111 }
112 
113 /* Flash Functions */
114 
115 /*
116  * file_erase() - Erase the flash
117  * @context:	The mbox context pointer
118  * @offset:	The flash offset to erase (bytes)
119  * @size:	The number of bytes to erase
120  *
121  * Return:	0 on success otherwise negative error code
122  */
file_erase(struct backend * backend,uint32_t offset,uint32_t count)123 static int file_erase(struct backend *backend, uint32_t offset, uint32_t count)
124 {
125 	const uint32_t erase_size = 1 << backend->erase_size_shift;
126 	struct file_data *priv = backend->priv;
127 	struct erase_info_user erase_info = {0};
128 	int rc;
129 
130 	MSG_DBG("Erase flash @ 0x%.8x for 0x%.8x\n", offset, count);
131 
132 	uint8_t* erase_buf = (uint8_t*)malloc(count);
133 	if (!erase_buf) {
134 		MSG_ERR("Couldn't malloc erase buffer. %s\n", strerror(errno));
135 		return -1;
136 	}
137 	memset(erase_buf, 0xFF, erase_size);
138 	rc = pwrite(priv->fd, erase_buf, count, offset);
139 	free(erase_buf);
140 
141 	if (rc < 0) {
142 		MSG_ERR("Couldn't erase flash at 0x%.8x\n", erase_info.start);
143 		return -errno;
144 	}
145 
146 
147 	return 0;
148 }
149 
150 #define CHUNKSIZE (64 * 1024)
151 
152 /*
153  * file_copy() - Copy data from the flash device into a provided buffer
154  * @context:	The backend context pointer
155  * @offset:	The flash offset to copy from (bytes)
156  * @mem:	The buffer to copy into (must be of atleast 'size' bytes)
157  * @size:	The number of bytes to copy
158  * Return:	Number of bytes copied on success, otherwise negative error
159  *		code. file_copy will copy at most 'size' bytes, but it may
160  *		copy less.
161  */
file_copy(struct backend * backend,uint32_t offset,void * mem,uint32_t size)162 static int64_t file_copy(struct backend *backend, uint32_t offset,
163 			  void *mem, uint32_t size)
164 {
165 	struct file_data *priv = backend->priv;
166 	int32_t size_read;
167 	void *start = mem;
168 
169 	MSG_DBG("Copy flash to %p for size 0x%.8x from offset 0x%.8x\n", mem,
170 		size, offset);
171 	if (lseek(priv->fd, offset, SEEK_SET) != offset) {
172 		MSG_ERR("Couldn't seek flash at pos: %u %s\n", offset,
173 			strerror(errno));
174 		return -errno;
175 	}
176 
177 	do {
178 		size_read = read(priv->fd, mem, min_u32(CHUNKSIZE, size));
179 		if (size_read < 0) {
180 			MSG_ERR("Couldn't copy file into ram: %s\n",
181 				strerror(errno));
182 			return -errno;
183 		}
184 
185 		size -= size_read;
186 		mem += size_read;
187 	} while (size && size_read);
188 
189 	return size_read ? mem - start : -EIO;
190 }
191 
192 /*
193  * file_write() - Write the flash from a provided buffer
194  * @context:	The mbox context pointer
195  * @offset:	The flash offset to write to (bytes)
196  * @buf:	The buffer to write from (must be of atleast size)
197  * @size:	The number of bytes to write
198  *
199  * Return:	0 on success otherwise negative error code
200  */
file_write(struct backend * backend,uint32_t offset,void * buf,uint32_t count)201 static int file_write(struct backend *backend, uint32_t offset, void *buf,
202 		       uint32_t count)
203 {
204 	struct file_data *priv = backend->priv;
205 	uint32_t buf_offset = 0;
206 	int rc;
207 
208 	MSG_DBG("Write flash @ 0x%.8x for 0x%.8x from %p\n", offset, count,
209 		buf);
210 
211 	if (lseek(priv->fd, offset, SEEK_SET) != offset) {
212 		MSG_ERR("Couldn't seek flash at pos: %u %s\n", offset,
213 			strerror(errno));
214 		return -errno;
215 	}
216 
217 	while (count) {
218 		rc = write(priv->fd, buf + buf_offset, count);
219 		if (rc < 0) {
220 			MSG_ERR("Couldn't write to file, write lost: %s\n",
221 				strerror(errno));
222 			return -errno;
223 		}
224 		count -= rc;
225 		buf_offset += rc;
226 	}
227 
228 	return 0;
229 }
230 
231 /*
232  * file_reset() - Reset the lpc bus mapping
233  * @context:    The backend context pointer
234  * @buf:	Pointer to the LPC reserved memory
235  * @count:	The size of the LPC reserved memory
236  *
237  * Return:      0 on success otherwise negative error code
238  */
file_reset(struct backend * backend,void * buf,uint32_t count)239 static int file_reset(struct backend *backend, void *buf, uint32_t count)
240 {
241 	struct file_data *priv = backend->priv;
242 	size_t len;
243 	int rc;
244 
245 	len = MIN(backend->flash_size, count);
246 
247 	/* Ugh, otherwise we need to parse the FFS image */
248 	assert(len == backend->flash_size);
249 
250 	/* Preload Flash contents into memory window */
251 	rc = pread(priv->fd, buf, len, 0);
252 	if (rc < 0)
253 		return -errno;
254 
255 	return reset_lpc_memory;
256 }
257 
258 static const struct backend_ops file_ops = {
259 	.init = file_dev_init,
260 	.free = file_dev_free,
261 	.copy = file_copy,
262 	.erase = file_erase,
263 	.write = file_write,
264 	.reset = file_reset,
265 	.validate = NULL,
266 	.align_offset = NULL,
267 };
268 
backend_get_file(void)269 struct backend backend_get_file(void)
270 {
271 	struct backend be = {0};
272 
273 	be.ops = &file_ops;
274 
275 	return be;
276 }
277 
backend_probe_file(struct backend * master,const char * path)278 int backend_probe_file(struct backend *master, const char *path)
279 {
280 	struct backend with;
281 
282 	assert(master);
283 	with = backend_get_file();
284 
285 	return backend_init(master, &with, (void *)path);
286 }
287 
288 #pragma GCC diagnostic pop
289