1 /* memregion_direct.c
2 *
3 * Copyright (C) 2010 - 2013 UNISYS CORPORATION
4 * All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or (at
9 * your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
14 * NON INFRINGEMENT. See the GNU General Public License for more
15 * details.
16 */
17
18 /*
19 * This is an implementation of memory regions that can be used to read/write
20 * channel memory (in main memory of the host system) from code running in
21 * a virtual partition.
22 */
23 #include "timskmod.h"
24 #include "memregion.h"
25
26 #define MYDRVNAME "memregion"
27
28 struct memregion {
29 HOSTADDRESS physaddr;
30 ulong nbytes;
31 void __iomem *mapped;
32 BOOL requested;
33 BOOL overlapped;
34 };
35
36 static BOOL mapit(struct memregion *memregion);
37 static void unmapit(struct memregion *memregion);
38
39 struct memregion *
visor_memregion_create(HOSTADDRESS physaddr,ulong nbytes)40 visor_memregion_create(HOSTADDRESS physaddr, ulong nbytes)
41 {
42 struct memregion *rc = NULL;
43 struct memregion *memregion;
44
45 memregion = kzalloc(sizeof(*memregion), GFP_KERNEL | __GFP_NORETRY);
46 if (memregion == NULL)
47 return NULL;
48
49 memregion->physaddr = physaddr;
50 memregion->nbytes = nbytes;
51 memregion->overlapped = FALSE;
52 if (!mapit(memregion)) {
53 rc = NULL;
54 goto cleanup;
55 }
56 rc = memregion;
57 cleanup:
58 if (rc == NULL) {
59 visor_memregion_destroy(memregion);
60 memregion = NULL;
61 }
62 return rc;
63 }
64 EXPORT_SYMBOL_GPL(visor_memregion_create);
65
66 struct memregion *
visor_memregion_create_overlapped(struct memregion * parent,ulong offset,ulong nbytes)67 visor_memregion_create_overlapped(struct memregion *parent, ulong offset,
68 ulong nbytes)
69 {
70 struct memregion *memregion = NULL;
71
72 if (parent == NULL)
73 return NULL;
74
75 if (parent->mapped == NULL)
76 return NULL;
77
78 if ((offset >= parent->nbytes) ||
79 ((offset + nbytes) >= parent->nbytes))
80 return NULL;
81
82 memregion = kzalloc(sizeof(*memregion), GFP_KERNEL|__GFP_NORETRY);
83 if (memregion == NULL)
84 return NULL;
85
86 memregion->physaddr = parent->physaddr + offset;
87 memregion->nbytes = nbytes;
88 memregion->mapped = ((u8 __iomem *)(parent->mapped)) + offset;
89 memregion->requested = FALSE;
90 memregion->overlapped = TRUE;
91 return memregion;
92 }
93 EXPORT_SYMBOL_GPL(visor_memregion_create_overlapped);
94
95 static BOOL
mapit(struct memregion * memregion)96 mapit(struct memregion *memregion)
97 {
98 ulong physaddr = (ulong)(memregion->physaddr);
99 ulong nbytes = memregion->nbytes;
100
101 memregion->requested = FALSE;
102 if (request_mem_region(physaddr, nbytes, MYDRVNAME))
103 memregion->requested = TRUE;
104 memregion->mapped = ioremap_cache(physaddr, nbytes);
105 if (!memregion->mapped)
106 return FALSE;
107 return TRUE;
108 }
109
110 static void
unmapit(struct memregion * memregion)111 unmapit(struct memregion *memregion)
112 {
113 if (memregion->mapped != NULL) {
114 iounmap(memregion->mapped);
115 memregion->mapped = NULL;
116 }
117 if (memregion->requested) {
118 release_mem_region((ulong)(memregion->physaddr),
119 memregion->nbytes);
120 memregion->requested = FALSE;
121 }
122 }
123
124 HOSTADDRESS
visor_memregion_get_physaddr(struct memregion * memregion)125 visor_memregion_get_physaddr(struct memregion *memregion)
126 {
127 return memregion->physaddr;
128 }
129 EXPORT_SYMBOL_GPL(visor_memregion_get_physaddr);
130
131 ulong
visor_memregion_get_nbytes(struct memregion * memregion)132 visor_memregion_get_nbytes(struct memregion *memregion)
133 {
134 return memregion->nbytes;
135 }
136 EXPORT_SYMBOL_GPL(visor_memregion_get_nbytes);
137
138 void __iomem *
visor_memregion_get_pointer(struct memregion * memregion)139 visor_memregion_get_pointer(struct memregion *memregion)
140 {
141 return memregion->mapped;
142 }
143 EXPORT_SYMBOL_GPL(visor_memregion_get_pointer);
144
145 int
visor_memregion_resize(struct memregion * memregion,ulong newsize)146 visor_memregion_resize(struct memregion *memregion, ulong newsize)
147 {
148 if (newsize == memregion->nbytes)
149 return 0;
150 if (memregion->overlapped)
151 /* no error check here - we no longer know the
152 * parent's range!
153 */
154 memregion->nbytes = newsize;
155 else {
156 unmapit(memregion);
157 memregion->nbytes = newsize;
158 if (!mapit(memregion))
159 return -1;
160 }
161 return 0;
162 }
163 EXPORT_SYMBOL_GPL(visor_memregion_resize);
164
165 static int
memregion_readwrite(BOOL is_write,struct memregion * memregion,ulong offset,void * local,ulong nbytes)166 memregion_readwrite(BOOL is_write,
167 struct memregion *memregion, ulong offset,
168 void *local, ulong nbytes)
169 {
170 if (offset + nbytes > memregion->nbytes)
171 return -EIO;
172
173 if (is_write)
174 memcpy_toio(memregion->mapped + offset, local, nbytes);
175 else
176 memcpy_fromio(local, memregion->mapped + offset, nbytes);
177
178 return 0;
179 }
180
181 int
visor_memregion_read(struct memregion * memregion,ulong offset,void * dest,ulong nbytes)182 visor_memregion_read(struct memregion *memregion, ulong offset, void *dest,
183 ulong nbytes)
184 {
185 return memregion_readwrite(FALSE, memregion, offset, dest, nbytes);
186 }
187 EXPORT_SYMBOL_GPL(visor_memregion_read);
188
189 int
visor_memregion_write(struct memregion * memregion,ulong offset,void * src,ulong nbytes)190 visor_memregion_write(struct memregion *memregion, ulong offset, void *src,
191 ulong nbytes)
192 {
193 return memregion_readwrite(TRUE, memregion, offset, src, nbytes);
194 }
195 EXPORT_SYMBOL_GPL(visor_memregion_write);
196
197 void
visor_memregion_destroy(struct memregion * memregion)198 visor_memregion_destroy(struct memregion *memregion)
199 {
200 if (memregion == NULL)
201 return;
202 if (!memregion->overlapped)
203 unmapit(memregion);
204 kfree(memregion);
205 }
206 EXPORT_SYMBOL_GPL(visor_memregion_destroy);
207
208