xref: /freebsd/stand/common/md.c (revision a259b98fa211ed87bfee58c575de4e2de94ee0fa)
1 /*-
2  * Copyright (c) 2009 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <stand.h>
28 #include <sys/param.h>
29 #include <sys/endian.h>
30 #include <sys/queue.h>
31 #include <sys/stdarg.h>
32 
33 #include "bootstrap.h"
34 
35 #define	MD_BLOCK_SIZE	512
36 #define	MD_FLAG_MASK	MD_FLAG_KERNEL
37 
38 struct md_info {
39 	STAILQ_ENTRY(md_info) md_link;
40 	void		*md_image;
41 	size_t		 md_size;
42 	unsigned int	 md_flags;
43 	int		 md_unit;
44 };
45 
46 static STAILQ_HEAD(, md_info) md_list = STAILQ_HEAD_INITIALIZER(md_list);
47 static int md_next_unit;
48 
49 static int md_init(void);
50 static int md_strategy(void *, int, daddr_t, size_t, char *, size_t *);
51 static int md_open(struct open_file *, ...);
52 static int md_close(struct open_file *);
53 static int md_print(int);
54 
55 struct devsw md_dev = {
56 	.dv_name = "md",
57 	.dv_type = DEVT_DISK,
58 	.dv_init = md_init,
59 	.dv_strategy = md_strategy,
60 	.dv_open = md_open,
61 	.dv_close = md_close,
62 	.dv_ioctl = noioctl,
63 	.dv_print = md_print,
64 	.dv_cleanup = nullsys,
65 };
66 
67 /*
68  * The kernel can accept a MD inline in the metadata, or out-of-line via
69  * hints, like when memory disks are passed to us in, for example, UEFI.
70  */
71 void
72 md_export_to_kernel(uint64_t start, uint64_t len)
73 {
74 	char key[32], value[32];
75 	static int unit = 0;	/* Note: loader unit and kernel unit may differ */
76 
77 	snprintf(key, sizeof(key), "hint.md.%d.physaddr", unit);
78 	snprintf(value, sizeof(value), "0x%016jx", (uintmax_t)start);
79 	setenv(key, value, 1);
80 	snprintf(key, sizeof(key), "hint.md.%d.len", unit);
81 	snprintf(value, sizeof(value), "%jd", (uintmax_t)len);
82 	setenv(key, value, 1);
83 	unit++;
84 }
85 
86 static struct md_info *
87 md_get_info(int unit)
88 {
89 	struct md_info *md;
90 
91 	STAILQ_FOREACH(md, &md_list, md_link) {
92 		if (md->md_unit == unit)
93 			return (md);
94 	}
95 	return (NULL);
96 }
97 
98 int
99 md_register(void *image, size_t size, unsigned int flags)
100 {
101 	struct md_info *md;
102 
103 	if (image == NULL || size == 0 || size % MD_BLOCK_SIZE != 0 ||
104 	    (flags & ~MD_FLAG_MASK) != 0) {
105 		errno = EINVAL;
106 		return (-1);
107 	}
108 	md = malloc(sizeof(*md));
109 	if (md == NULL) {
110 		errno = ENOMEM;
111 		return (-1);
112 	}
113 	md->md_image = image;
114 	md->md_size = size;
115 	md->md_flags = flags;
116 	md->md_unit = md_next_unit++;
117 	STAILQ_INSERT_TAIL(&md_list, md, md_link);
118 
119 	if ((flags & MD_FLAG_KERNEL) != 0)
120 		md_export_to_kernel((uintptr_t)image, size);
121 	return (md->md_unit);
122 }
123 
124 #ifdef MD_IMAGE_SIZE
125 
126 #if (MD_IMAGE_SIZE == 0 || MD_IMAGE_SIZE % MD_BLOCK_SIZE)
127 #error Image size must be a multiple of 512.
128 #endif
129 
130 /*
131  * Preloaded image gets put here.
132  * Applications that patch the object with the image can determine
133  * the size looking at the start and end markers (strings),
134  * so we want them contiguous.
135  */
136 static struct {
137 	u_char start[MD_IMAGE_SIZE];
138 	u_char end[128];
139 } md_image = {
140 	.start = "MFS Filesystem goes here",
141 	.end = "MFS Filesystem had better STOP here",
142 };
143 #endif
144 
145 static int
146 md_init(void)
147 {
148 
149 #ifdef MD_IMAGE_SIZE
150 	if (md_register(md_image.start, MD_IMAGE_SIZE, 0) < 0)
151 		return (errno);
152 #endif
153 	return (0);
154 }
155 
156 static int
157 md_strategy(void *devdata, int rw, daddr_t blk, size_t size,
158     char *buf, size_t *rsize)
159 {
160 	struct devdesc *dev = (struct devdesc *)devdata;
161 	struct md_info *md;
162 	size_t ofs;
163 
164 	md = md_get_info(dev->d_unit);
165 	if (md == NULL)
166 		return (ENXIO);
167 
168 	if (blk < 0 || (uintmax_t)blk >= md->md_size / MD_BLOCK_SIZE)
169 		return (EIO);
170 
171 	if (size % MD_BLOCK_SIZE)
172 		return (EIO);
173 
174 	ofs = blk * MD_BLOCK_SIZE;
175 	if (size > md->md_size - ofs)
176 		size = md->md_size - ofs;
177 
178 	if (rsize != NULL)
179 		*rsize = size;
180 
181 	switch (rw & F_MASK) {
182 	case F_READ:
183 		bcopy((char *)md->md_image + ofs, buf, size);
184 		return (0);
185 	case F_WRITE:
186 		bcopy(buf, (char *)md->md_image + ofs, size);
187 		return (0);
188 	}
189 
190 	return (ENODEV);
191 }
192 
193 static int
194 md_open(struct open_file *f, ...)
195 {
196 	va_list ap;
197 	struct devdesc *dev;
198 
199 	va_start(ap, f);
200 	dev = va_arg(ap, struct devdesc *);
201 	va_end(ap);
202 
203 	if (md_get_info(dev->d_unit) == NULL)
204 		return (ENXIO);
205 
206 	return (0);
207 }
208 
209 static int
210 md_close(struct open_file *f)
211 {
212 	struct devdesc *dev;
213 
214 	dev = (struct devdesc *)(f->f_devdata);
215 	return (md_get_info(dev->d_unit) == NULL ? ENXIO : 0);
216 }
217 
218 static int
219 md_print(int verbose)
220 {
221 	struct md_info *md;
222 	int ret;
223 
224 	if (STAILQ_EMPTY(&md_list))
225 		return (0);
226 	printf("%s devices:", md_dev.dv_name);
227 	if ((ret = pager_output("\n")) != 0)
228 		return (ret);
229 
230 	STAILQ_FOREACH(md, &md_list, md_link) {
231 		printf("    %s%d:    %ju X %u blocks", md_dev.dv_name,
232 		    md->md_unit, (uintmax_t)(md->md_size / MD_BLOCK_SIZE),
233 		    MD_BLOCK_SIZE);
234 		if ((ret = pager_output("\n")) != 0)
235 			return (ret);
236 	}
237 	return (0);
238 }
239