1 | /* ramdisk.c -- RAM disk block device implementation |
---|
2 | * |
---|
3 | * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia |
---|
4 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
---|
5 | * |
---|
6 | * @(#) $Id$ |
---|
7 | */ |
---|
8 | |
---|
9 | #if HAVE_CONFIG_H |
---|
10 | #include "config.h" |
---|
11 | #endif |
---|
12 | |
---|
13 | #include <rtems.h> |
---|
14 | #include <rtems/libio.h> |
---|
15 | #include <errno.h> |
---|
16 | #include <stdlib.h> |
---|
17 | #include <stdio.h> |
---|
18 | #include <string.h> |
---|
19 | #include <inttypes.h> |
---|
20 | |
---|
21 | #include "rtems/blkdev.h" |
---|
22 | #include "rtems/diskdevs.h" |
---|
23 | #include "rtems/ramdisk.h" |
---|
24 | |
---|
25 | /** |
---|
26 | * Control tracing. It can be compiled out of the code for small |
---|
27 | * footprint targets. Leave in by default. |
---|
28 | */ |
---|
29 | #if !defined (RTEMS_RAMDISK_TRACE) |
---|
30 | #define RTEMS_RAMDISK_TRACE 0 |
---|
31 | #endif |
---|
32 | |
---|
33 | #define RAMDISK_DEVICE_BASE_NAME "/dev/ramdisk" |
---|
34 | |
---|
35 | /* Internal RAM disk descriptor */ |
---|
36 | struct ramdisk { |
---|
37 | int block_size; /* RAM disk block size */ |
---|
38 | int block_num; /* Number of blocks on this RAM disk */ |
---|
39 | void *area; /* RAM disk memory area */ |
---|
40 | bool initialized;/* RAM disk is initialized */ |
---|
41 | bool malloced; /* != 0, if memory allocated by malloc for this |
---|
42 | RAM disk */ |
---|
43 | #if RTEMS_RAMDISK_TRACE |
---|
44 | int info_level; /* Trace level */ |
---|
45 | #endif |
---|
46 | }; |
---|
47 | |
---|
48 | static struct ramdisk *ramdisk; |
---|
49 | static uint32_t nramdisks; |
---|
50 | |
---|
51 | #if RTEMS_RAMDISK_TRACE |
---|
52 | /** |
---|
53 | * Print a message to the ramdisk output and flush it. |
---|
54 | * |
---|
55 | * @param rd The ramdisk control structure. |
---|
56 | * @param format The format string. See printf for details. |
---|
57 | * @param ... The arguments for the format text. |
---|
58 | * @return int The number of bytes written to the output. |
---|
59 | */ |
---|
60 | static int |
---|
61 | rtems_ramdisk_printf (struct ramdisk *rd, const char *format, ...) |
---|
62 | { |
---|
63 | int ret = 0; |
---|
64 | if (rd->info_level >= 1) |
---|
65 | { |
---|
66 | va_list args; |
---|
67 | va_start (args, format); |
---|
68 | fprintf (stdout, "ramdisk:"); |
---|
69 | ret = vfprintf (stdout, format, args); |
---|
70 | fprintf (stdout, "\n"); |
---|
71 | fflush (stdout); |
---|
72 | } |
---|
73 | return ret; |
---|
74 | } |
---|
75 | #endif |
---|
76 | |
---|
77 | /* ramdisk_read -- |
---|
78 | * RAM disk READ request handler. This primitive copies data from RAM |
---|
79 | * disk to supplied buffer and invoke the callout function to inform |
---|
80 | * upper layer that reading is completed. |
---|
81 | * |
---|
82 | * PARAMETERS: |
---|
83 | * req - pointer to the READ block device request info |
---|
84 | * |
---|
85 | * RETURNS: |
---|
86 | * ioctl return value |
---|
87 | */ |
---|
88 | static int |
---|
89 | ramdisk_read(struct ramdisk *rd, rtems_blkdev_request *req) |
---|
90 | { |
---|
91 | char *from; |
---|
92 | uint32_t i; |
---|
93 | rtems_blkdev_sg_buffer *sg; |
---|
94 | uint32_t remains; |
---|
95 | |
---|
96 | #if RTEMS_RAMDISK_TRACE |
---|
97 | rtems_ramdisk_printf (rd, "ramdisk read: start=%d, blocks=%d remains=%d", |
---|
98 | req->bufs[0].block, req->bufnum, |
---|
99 | rd->block_size * req->count); |
---|
100 | #endif |
---|
101 | |
---|
102 | remains = rd->block_size * req->bufnum; |
---|
103 | sg = req->bufs; |
---|
104 | for (i = 0; (remains > 0) && (i < req->bufnum); i++, sg++) |
---|
105 | { |
---|
106 | uint32_t count = sg->length; |
---|
107 | from = ((char *)rd->area + (sg->block * rd->block_size)); |
---|
108 | if (count > remains) |
---|
109 | count = remains; |
---|
110 | memcpy(sg->buffer, from, count); |
---|
111 | remains -= count; |
---|
112 | from += count; |
---|
113 | } |
---|
114 | req->req_done(req->done_arg, RTEMS_SUCCESSFUL, 0); |
---|
115 | return 0; |
---|
116 | } |
---|
117 | |
---|
118 | /* ramdisk_write -- |
---|
119 | * RAM disk WRITE request handler. This primitive copies data from |
---|
120 | * supplied buffer to RAM disk and invoke the callout function to inform |
---|
121 | * upper layer that writing is completed. |
---|
122 | * |
---|
123 | * PARAMETERS: |
---|
124 | * req - pointer to the WRITE block device request info |
---|
125 | * |
---|
126 | * RETURNS: |
---|
127 | * ioctl return value |
---|
128 | */ |
---|
129 | static int |
---|
130 | ramdisk_write(struct ramdisk *rd, rtems_blkdev_request *req) |
---|
131 | { |
---|
132 | char *to; |
---|
133 | uint32_t i; |
---|
134 | rtems_blkdev_sg_buffer *sg; |
---|
135 | uint32_t remains; |
---|
136 | |
---|
137 | #if RTEMS_RAMDISK_TRACE |
---|
138 | rtems_ramdisk_printf (rd, "ramdisk write: start=%d, blocks=%d remains=%d", |
---|
139 | req->bufs[0].block, req->bufnum, |
---|
140 | rd->block_size * req->bufnum); |
---|
141 | #endif |
---|
142 | remains = rd->block_size * req->bufnum; |
---|
143 | sg = req->bufs; |
---|
144 | for (i = 0; (remains > 0) && (i < req->bufnum); i++, sg++) |
---|
145 | { |
---|
146 | uint32_t count = sg->length; |
---|
147 | to = ((char *)rd->area + (sg->block * rd->block_size)); |
---|
148 | if (count > remains) |
---|
149 | count = remains; |
---|
150 | memcpy(to, sg->buffer, count); |
---|
151 | remains -= count; |
---|
152 | to += count; |
---|
153 | } |
---|
154 | req->req_done(req->done_arg, RTEMS_SUCCESSFUL, 0); |
---|
155 | return 0; |
---|
156 | } |
---|
157 | |
---|
158 | /* ramdisk_ioctl -- |
---|
159 | * IOCTL handler for RAM disk device. |
---|
160 | * |
---|
161 | * PARAMETERS: |
---|
162 | * dev - device number (major, minor number) |
---|
163 | * req - IOCTL request code |
---|
164 | * argp - IOCTL argument |
---|
165 | * |
---|
166 | * RETURNS: |
---|
167 | * IOCTL return value |
---|
168 | */ |
---|
169 | static int |
---|
170 | ramdisk_ioctl(dev_t dev, uint32_t req, void *argp) |
---|
171 | { |
---|
172 | switch (req) |
---|
173 | { |
---|
174 | case RTEMS_BLKIO_REQUEST: |
---|
175 | { |
---|
176 | rtems_device_minor_number minor; |
---|
177 | rtems_blkdev_request *r = argp; |
---|
178 | struct ramdisk *rd; |
---|
179 | |
---|
180 | minor = rtems_filesystem_dev_minor_t(dev); |
---|
181 | if ((minor >= nramdisks) || !ramdisk[minor].initialized) |
---|
182 | { |
---|
183 | errno = ENODEV; |
---|
184 | return -1; |
---|
185 | } |
---|
186 | |
---|
187 | rd = ramdisk + minor; |
---|
188 | |
---|
189 | switch (r->req) |
---|
190 | { |
---|
191 | case RTEMS_BLKDEV_REQ_READ: |
---|
192 | return ramdisk_read(rd, r); |
---|
193 | |
---|
194 | case RTEMS_BLKDEV_REQ_WRITE: |
---|
195 | return ramdisk_write(rd, r); |
---|
196 | |
---|
197 | default: |
---|
198 | errno = EBADRQC; |
---|
199 | return -1; |
---|
200 | } |
---|
201 | break; |
---|
202 | } |
---|
203 | |
---|
204 | default: |
---|
205 | errno = EBADRQC; |
---|
206 | return -1; |
---|
207 | } |
---|
208 | } |
---|
209 | |
---|
210 | /* ramdisk_initialize -- |
---|
211 | * RAM disk device driver initialization. Run through RAM disk |
---|
212 | * configuration information and configure appropriate RAM disks. |
---|
213 | * |
---|
214 | * PARAMETERS: |
---|
215 | * major - RAM disk major device number |
---|
216 | * minor - minor device number, not applicable |
---|
217 | * arg - initialization argument, not applicable |
---|
218 | * |
---|
219 | * RETURNS: |
---|
220 | * none |
---|
221 | */ |
---|
222 | rtems_device_driver |
---|
223 | ramdisk_initialize( |
---|
224 | rtems_device_major_number major, |
---|
225 | rtems_device_minor_number minor __attribute__((unused)), |
---|
226 | void *arg __attribute__((unused))) |
---|
227 | { |
---|
228 | rtems_device_minor_number i; |
---|
229 | rtems_ramdisk_config *c = rtems_ramdisk_configuration; |
---|
230 | struct ramdisk *r; |
---|
231 | rtems_status_code rc; |
---|
232 | |
---|
233 | rc = rtems_disk_io_initialize(); |
---|
234 | if (rc != RTEMS_SUCCESSFUL) |
---|
235 | return rc; |
---|
236 | |
---|
237 | r = ramdisk = calloc(rtems_ramdisk_configuration_size, |
---|
238 | sizeof(struct ramdisk)); |
---|
239 | #if RTEMS_RAMDISK_TRACE |
---|
240 | r->info_level = 1; |
---|
241 | #endif |
---|
242 | for (i = 0; i < rtems_ramdisk_configuration_size; i++, c++, r++) |
---|
243 | { |
---|
244 | dev_t dev = rtems_filesystem_make_dev_t(major, i); |
---|
245 | char name[sizeof(RAMDISK_DEVICE_BASE_NAME "0123456789")]; |
---|
246 | snprintf(name, sizeof(name), RAMDISK_DEVICE_BASE_NAME "%" PRIu32, i); |
---|
247 | r->block_size = c->block_size; |
---|
248 | r->block_num = c->block_num; |
---|
249 | if (c->location == NULL) |
---|
250 | { |
---|
251 | r->malloced = true; |
---|
252 | r->area = malloc(r->block_size * r->block_num); |
---|
253 | if (r->area == NULL) /* No enough memory for this disk */ |
---|
254 | { |
---|
255 | r->initialized = false; |
---|
256 | continue; |
---|
257 | } |
---|
258 | else |
---|
259 | { |
---|
260 | r->initialized = true; |
---|
261 | } |
---|
262 | } |
---|
263 | else |
---|
264 | { |
---|
265 | r->malloced = false; |
---|
266 | r->initialized = true; |
---|
267 | r->area = c->location; |
---|
268 | } |
---|
269 | rc = rtems_disk_create_phys(dev, c->block_size, c->block_num, |
---|
270 | ramdisk_ioctl, name); |
---|
271 | if (rc != RTEMS_SUCCESSFUL) |
---|
272 | { |
---|
273 | if (r->malloced) |
---|
274 | { |
---|
275 | free(r->area); |
---|
276 | } |
---|
277 | r->initialized = false; |
---|
278 | } |
---|
279 | } |
---|
280 | nramdisks = rtems_ramdisk_configuration_size; |
---|
281 | return RTEMS_SUCCESSFUL; |
---|
282 | } |
---|