1 /*-
2 * Copyright (c) 2016 Landon Fuller <landonf@FreeBSD.org>
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 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13 * redistribution must be conditioned upon including a substantially
14 * similar Disclaimer requirement for further binary redistribution.
15 *
16 * NO WARRANTY
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27 * THE POSSIBILITY OF SUCH DAMAGES.
28 */
29
30 #include <sys/cdefs.h>
31 #ifdef _KERNEL
32 #include <sys/param.h>
33 #include <sys/malloc.h>
34 #include <sys/systm.h>
35 #else /* !_KERNEL */
36 #include <errno.h>
37 #include <stdint.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #endif /* _KERNEL */
41
42 #include "bhnd_nvram_private.h"
43
44 #include "bhnd_nvram_io.h"
45 #include "bhnd_nvram_iovar.h"
46
47 /**
48 * Memory-backed NVRAM I/O context.
49 *
50 * ioptr instances are gauranteed to provide persistent references to its
51 * backing contigious memory via bhnd_nvram_io_read_ptr() and
52 * bhnd_nvram_io_write_ptr().
53 */
54 struct bhnd_nvram_ioptr {
55 struct bhnd_nvram_io io; /**< common I/O instance state */
56 void *ptr; /**< backing memory */
57 size_t size; /**< size at @p ptr */
58 size_t capacity; /**< capacity at @p ptr */
59 uint32_t flags; /**< flags (see BHND_NVRAM_IOPTR_*) */
60 };
61
BHND_NVRAM_IOPS_DEFN(ioptr)62 BHND_NVRAM_IOPS_DEFN(ioptr)
63
64 /**
65 * Allocate and return a new I/O context, mapping @p size bytes at @p ptr.
66
67 * The caller is responsible for deallocating the returned I/O context via
68 * bhnd_nvram_io_free().
69 *
70 * @param ptr The pointer to be mapped by the returned I/O
71 * context. Must remain valid for the lifetime of
72 * the returned I/O context.
73 * @param size The total number of bytes mapped at @p ptr.
74 * @param capacity The maximum number of bytes that may be mapped
75 * at @p ptr via bhnd_nvram_ioptr_setsize().
76 * @param flags Access flags (see BHND_NVRAM_IOPTR_*).
77 *
78 * @retval bhnd_nvram_io success.
79 * @retval NULL allocation failed.
80 * @retval NULL the requested @p capacity is less than @p size.
81 */
82 struct bhnd_nvram_io *
83 bhnd_nvram_ioptr_new(const void *ptr, size_t size, size_t capacity,
84 uint32_t flags)
85 {
86 struct bhnd_nvram_ioptr *ioptr;
87
88 /* Sanity check the capacity */
89 if (size > capacity)
90 return (NULL);
91
92 /* Allocate I/O context */
93 ioptr = bhnd_nv_malloc(sizeof(*ioptr));
94 if (ioptr == NULL)
95 return (NULL);
96
97 ioptr->io.iops = &bhnd_nvram_ioptr_ops;
98 ioptr->ptr = __DECONST(void *, ptr);
99 ioptr->size = size;
100 ioptr->capacity = capacity;
101 ioptr->flags = flags;
102
103 return (&ioptr->io);
104 }
105
106 static void
bhnd_nvram_ioptr_free(struct bhnd_nvram_io * io)107 bhnd_nvram_ioptr_free(struct bhnd_nvram_io *io)
108 {
109 bhnd_nv_free(io);
110 }
111
112 static size_t
bhnd_nvram_ioptr_getsize(struct bhnd_nvram_io * io)113 bhnd_nvram_ioptr_getsize(struct bhnd_nvram_io *io)
114 {
115 struct bhnd_nvram_ioptr *ioptr = (struct bhnd_nvram_ioptr *)io;
116 return (ioptr->size);
117 }
118
119 static int
bhnd_nvram_ioptr_setsize(struct bhnd_nvram_io * io,size_t size)120 bhnd_nvram_ioptr_setsize(struct bhnd_nvram_io *io, size_t size)
121 {
122 struct bhnd_nvram_ioptr *ioptr = (struct bhnd_nvram_ioptr *)io;
123
124 /* Must be writable */
125 if (!(ioptr->flags & BHND_NVRAM_IOPTR_RDWR))
126 return (ENODEV);
127
128 /* Can't exceed the actual capacity */
129 if (size > ioptr->capacity)
130 return (ENXIO);
131
132 ioptr->size = size;
133 return (0);
134 }
135
136 /* Common ioptr_(read|write)_ptr implementation */
137 static int
bhnd_nvram_ioptr_ptr(struct bhnd_nvram_ioptr * ioptr,size_t offset,void ** ptr,size_t nbytes,size_t * navail)138 bhnd_nvram_ioptr_ptr(struct bhnd_nvram_ioptr *ioptr, size_t offset, void **ptr,
139 size_t nbytes, size_t *navail)
140 {
141 size_t avail;
142
143 /* Verify offset+nbytes fall within the buffer range */
144 if (offset > ioptr->size)
145 return (ENXIO);
146
147 avail = ioptr->size - offset;
148 if (avail < nbytes)
149 return (ENXIO);
150
151 /* Valid I/O range, provide a pointer to the buffer and the
152 * total count of available bytes */
153 *ptr = ((uint8_t *)ioptr->ptr) + offset;
154 if (navail != NULL)
155 *navail = avail;
156
157 return (0);
158 }
159
160 static int
bhnd_nvram_ioptr_read_ptr(struct bhnd_nvram_io * io,size_t offset,const void ** ptr,size_t nbytes,size_t * navail)161 bhnd_nvram_ioptr_read_ptr(struct bhnd_nvram_io *io, size_t offset,
162 const void **ptr, size_t nbytes, size_t *navail)
163 {
164 struct bhnd_nvram_ioptr *ioptr;
165 void *writep;
166 int error;
167
168 ioptr = (struct bhnd_nvram_ioptr *) io;
169
170 /* Return a pointer into our backing buffer */
171 error = bhnd_nvram_ioptr_ptr(ioptr, offset, &writep, nbytes, navail);
172 if (error)
173 return (error);
174
175 *ptr = writep;
176
177 return (0);
178 }
179
180 static int
bhnd_nvram_ioptr_write_ptr(struct bhnd_nvram_io * io,size_t offset,void ** ptr,size_t nbytes,size_t * navail)181 bhnd_nvram_ioptr_write_ptr(struct bhnd_nvram_io *io, size_t offset,
182 void **ptr, size_t nbytes, size_t *navail)
183 {
184 struct bhnd_nvram_ioptr *ioptr;
185
186 ioptr = (struct bhnd_nvram_ioptr *) io;
187
188 /* Must be writable */
189 if (!(ioptr->flags & BHND_NVRAM_IOPTR_RDWR))
190 return (ENODEV);
191
192 /* Return a pointer into our backing buffer */
193 return (bhnd_nvram_ioptr_ptr(ioptr, offset, ptr, nbytes, navail));
194 }
195
196 static int
bhnd_nvram_ioptr_read(struct bhnd_nvram_io * io,size_t offset,void * buffer,size_t nbytes)197 bhnd_nvram_ioptr_read(struct bhnd_nvram_io *io, size_t offset, void *buffer,
198 size_t nbytes)
199 {
200 const void *ptr;
201 int error;
202
203 /* Try to fetch a direct pointer for at least nbytes */
204 if ((error = bhnd_nvram_io_read_ptr(io, offset, &ptr, nbytes, NULL)))
205 return (error);
206
207 /* Copy out the requested data */
208 memcpy(buffer, ptr, nbytes);
209 return (0);
210 }
211
212 static int
bhnd_nvram_ioptr_write(struct bhnd_nvram_io * io,size_t offset,void * buffer,size_t nbytes)213 bhnd_nvram_ioptr_write(struct bhnd_nvram_io *io, size_t offset,
214 void *buffer, size_t nbytes)
215 {
216 void *ptr;
217 int error;
218
219 /* Try to fetch a direct pointer for at least nbytes */
220 if ((error = bhnd_nvram_io_write_ptr(io, offset, &ptr, nbytes, NULL)))
221 return (error);
222
223 /* Copy in the provided data */
224 memcpy(ptr, buffer, nbytes);
225 return (0);
226 }
227