Commit | Line | Data |
---|---|---|
da7c5cc6 | 1 | /* |
0880b18e | 2 | * Copyright (c) 1982, 1986 Regents of the University of California. |
da7c5cc6 KM |
3 | * All rights reserved. The Berkeley software License Agreement |
4 | * specifies the terms and conditions for redistribution. | |
5 | * | |
92d92331 | 6 | * @(#)subr_rmap.c.sav 7.2 (Berkeley) %G% |
da7c5cc6 | 7 | */ |
2694e78a | 8 | |
94368568 JB |
9 | #include "param.h" |
10 | #include "systm.h" | |
11 | #include "map.h" | |
12 | #include "dir.h" | |
13 | #include "user.h" | |
14 | #include "proc.h" | |
15 | #include "text.h" | |
16 | #include "kernel.h" | |
2694e78a | 17 | |
b725a0ca BJ |
18 | /* |
19 | * Resource map handling routines. | |
20 | * | |
21 | * A resource map is an array of structures each | |
22 | * of which describes a segment of the address space of an available | |
23 | * resource. The segments are described by their base address and | |
24 | * length, and sorted in address order. Each resource map has a fixed | |
25 | * maximum number of segments allowed. Resources are allocated | |
26 | * by taking part or all of one of the segments of the map. | |
27 | * | |
28 | * Returning of resources will require another segment if | |
29 | * the returned resources are not adjacent in the address | |
30 | * space to an existing segment. If the return of a segment | |
31 | * would require a slot which is not available, then one of | |
32 | * the resource map segments is discarded after a warning is printed. | |
33 | * Returning of resources may also cause the map to collapse | |
34 | * by coalescing two existing segments and the returned space | |
35 | * into a single segment. In this case the resource map is | |
36 | * made smaller by copying together to fill the resultant gap. | |
37 | * | |
38 | * N.B.: the current implementation uses a dense array and does | |
39 | * not admit the value ``0'' as a legal address, since that is used | |
40 | * as a delimiter. | |
41 | */ | |
42 | ||
43 | /* | |
44 | * Initialize map mp to have (mapsize-2) segments | |
45 | * and to be called ``name'', which we print if | |
46 | * the slots become so fragmented that we lose space. | |
47 | * The map itself is initialized with size elements free | |
48 | * starting at addr. | |
49 | */ | |
50 | rminit(mp, size, addr, name, mapsize) | |
51 | register struct map *mp; | |
a29f7995 | 52 | long size, addr; |
b725a0ca BJ |
53 | char *name; |
54 | int mapsize; | |
55 | { | |
56 | register struct mapent *ep = (struct mapent *)(mp+1); | |
57 | ||
58 | mp->m_name = name; | |
59 | /* N.B.: WE ASSUME HERE THAT sizeof (struct map) == sizeof (struct mapent) */ | |
60 | /* | |
61 | * One of the mapsize slots is taken by the map structure, | |
62 | * segments has size 0 and addr 0, and acts as a delimiter. | |
63 | * We insure that we never use segments past the end of | |
64 | * the array which is given by mp->m_limit. | |
65 | * Instead, when excess segments occur we discard some resources. | |
66 | */ | |
67 | mp->m_limit = (struct mapent *)&mp[mapsize]; | |
68 | /* | |
69 | * Simulate a rmfree(), but with the option to | |
70 | * call with size 0 and addr 0 when we just want | |
71 | * to initialize without freeing. | |
72 | */ | |
73 | ep->m_size = size; | |
74 | ep->m_addr = addr; | |
75 | } | |
76 | ||
2694e78a BJ |
77 | /* |
78 | * Allocate 'size' units from the given | |
b725a0ca | 79 | * map. Return the base of the allocated space. |
2694e78a BJ |
80 | * In a map, the addresses are increasing and the |
81 | * list is terminated by a 0 size. | |
b725a0ca | 82 | * |
2694e78a | 83 | * Algorithm is first-fit. |
b725a0ca BJ |
84 | * |
85 | * This routine knows about the interleaving of the swapmap | |
86 | * and handles that. | |
2694e78a | 87 | */ |
39d536e6 | 88 | long |
b725a0ca BJ |
89 | rmalloc(mp, size) |
90 | register struct map *mp; | |
39d536e6 | 91 | long size; |
2694e78a | 92 | { |
b725a0ca BJ |
93 | register struct mapent *ep = (struct mapent *)(mp+1); |
94 | register int addr; | |
95 | register struct mapent *bp; | |
41888f16 | 96 | swblk_t first, rest; |
2694e78a | 97 | |
d668d9ba | 98 | if (size <= 0 || mp == swapmap && size > dmmax) |
b725a0ca BJ |
99 | panic("rmalloc"); |
100 | /* | |
101 | * Search for a piece of the resource map which has enough | |
102 | * free space to accomodate the request. | |
103 | */ | |
104 | for (bp = ep; bp->m_size; bp++) { | |
2694e78a | 105 | if (bp->m_size >= size) { |
b725a0ca BJ |
106 | /* |
107 | * If allocating from swapmap, | |
108 | * then have to respect interleaving | |
109 | * boundaries. | |
110 | */ | |
d668d9ba SL |
111 | if (mp == swapmap && nswdev > 1 && |
112 | (first = dmmax - bp->m_addr%dmmax) < bp->m_size) { | |
41888f16 BJ |
113 | if (bp->m_size - first < size) |
114 | continue; | |
b725a0ca | 115 | addr = bp->m_addr + first; |
41888f16 BJ |
116 | rest = bp->m_size - first - size; |
117 | bp->m_size = first; | |
118 | if (rest) | |
b725a0ca BJ |
119 | rmfree(swapmap, rest, addr+size); |
120 | return (addr); | |
41888f16 | 121 | } |
b725a0ca BJ |
122 | /* |
123 | * Allocate from the map. | |
124 | * If there is no space left of the piece | |
125 | * we allocated from, move the rest of | |
126 | * the pieces to the left. | |
127 | */ | |
128 | addr = bp->m_addr; | |
2694e78a BJ |
129 | bp->m_addr += size; |
130 | if ((bp->m_size -= size) == 0) { | |
131 | do { | |
132 | bp++; | |
133 | (bp-1)->m_addr = bp->m_addr; | |
134 | } while ((bp-1)->m_size = bp->m_size); | |
135 | } | |
b725a0ca BJ |
136 | if (mp == swapmap && addr % CLSIZE) |
137 | panic("rmalloc swapmap"); | |
138 | return (addr); | |
2694e78a BJ |
139 | } |
140 | } | |
b725a0ca | 141 | return (0); |
2694e78a BJ |
142 | } |
143 | ||
144 | /* | |
b725a0ca | 145 | * Free the previously allocated space at addr |
2694e78a | 146 | * of size units into the specified map. |
b725a0ca | 147 | * Sort addr into map and combine on |
2694e78a BJ |
148 | * one or both ends if possible. |
149 | */ | |
b725a0ca BJ |
150 | rmfree(mp, size, addr) |
151 | struct map *mp; | |
39d536e6 | 152 | long size, addr; |
2694e78a | 153 | { |
b725a0ca BJ |
154 | struct mapent *firstbp; |
155 | register struct mapent *bp; | |
2694e78a BJ |
156 | register int t; |
157 | ||
b725a0ca BJ |
158 | /* |
159 | * Both address and size must be | |
160 | * positive, or the protocol has broken down. | |
161 | */ | |
162 | if (addr <= 0 || size <= 0) | |
163 | goto badrmfree; | |
164 | /* | |
165 | * Locate the piece of the map which starts after the | |
166 | * returned space (or the end of the map). | |
167 | */ | |
168 | firstbp = bp = (struct mapent *)(mp + 1); | |
169 | for (; bp->m_addr <= addr && bp->m_size != 0; bp++) | |
2694e78a | 170 | continue; |
b725a0ca BJ |
171 | /* |
172 | * If the piece on the left abuts us, | |
173 | * then we should combine with it. | |
174 | */ | |
175 | if (bp > firstbp && (bp-1)->m_addr+(bp-1)->m_size >= addr) { | |
176 | /* | |
177 | * Check no overlap (internal error). | |
178 | */ | |
179 | if ((bp-1)->m_addr+(bp-1)->m_size > addr) | |
180 | goto badrmfree; | |
181 | /* | |
182 | * Add into piece on the left by increasing its size. | |
183 | */ | |
2694e78a | 184 | (bp-1)->m_size += size; |
b725a0ca BJ |
185 | /* |
186 | * If the combined piece abuts the piece on | |
187 | * the right now, compress it in also, | |
188 | * by shifting the remaining pieces of the map over. | |
189 | */ | |
190 | if (bp->m_addr && addr+size >= bp->m_addr) { | |
191 | if (addr+size > bp->m_addr) | |
192 | goto badrmfree; | |
2694e78a BJ |
193 | (bp-1)->m_size += bp->m_size; |
194 | while (bp->m_size) { | |
195 | bp++; | |
196 | (bp-1)->m_addr = bp->m_addr; | |
197 | (bp-1)->m_size = bp->m_size; | |
198 | } | |
199 | } | |
b725a0ca BJ |
200 | goto done; |
201 | } | |
202 | /* | |
203 | * Don't abut on the left, check for abutting on | |
204 | * the right. | |
205 | */ | |
206 | if (addr+size >= bp->m_addr && bp->m_size) { | |
207 | if (addr+size > bp->m_addr) | |
208 | goto badrmfree; | |
209 | bp->m_addr -= size; | |
210 | bp->m_size += size; | |
211 | goto done; | |
212 | } | |
213 | /* | |
214 | * Don't abut at all. Make a new entry | |
215 | * and check for map overflow. | |
216 | */ | |
217 | do { | |
218 | t = bp->m_addr; | |
219 | bp->m_addr = addr; | |
220 | addr = t; | |
221 | t = bp->m_size; | |
222 | bp->m_size = size; | |
223 | bp++; | |
224 | } while (size = t); | |
225 | /* | |
226 | * Segment at bp is to be the delimiter; | |
227 | * If there is not room for it | |
228 | * then the table is too full | |
229 | * and we must discard something. | |
230 | */ | |
231 | if (bp+1 > mp->m_limit) { | |
232 | /* | |
233 | * Back bp up to last available segment. | |
234 | * which contains a segment already and must | |
235 | * be made into the delimiter. | |
236 | * Discard second to last entry, | |
237 | * since it is presumably smaller than the last | |
238 | * and move the last entry back one. | |
239 | */ | |
240 | bp--; | |
f4c13170 | 241 | printf("%s: rmap ovflo, lost [%d,%d)\n", mp->m_name, |
b725a0ca BJ |
242 | (bp-1)->m_addr, (bp-1)->m_addr+(bp-1)->m_size); |
243 | bp[-1] = bp[0]; | |
244 | bp[0].m_size = bp[0].m_addr = 0; | |
2694e78a | 245 | } |
b725a0ca BJ |
246 | done: |
247 | /* | |
248 | * THIS IS RIDICULOUS... IT DOESN'T BELONG HERE! | |
249 | */ | |
2694e78a BJ |
250 | if ((mp == kernelmap) && kmapwnt) { |
251 | kmapwnt = 0; | |
252 | wakeup((caddr_t)kernelmap); | |
253 | } | |
b725a0ca BJ |
254 | return; |
255 | badrmfree: | |
256 | panic("bad rmfree"); | |
2694e78a | 257 | } |
1c1f6ecf BF |
258 | |
259 | /* | |
260 | * Allocate 'size' units from the given map, starting at address 'addr'. | |
261 | * Return 'addr' if successful, 0 if not. | |
262 | * This may cause the creation or destruction of a resource map segment. | |
263 | * | |
264 | * This routine will return failure status if there is not enough room | |
265 | * for a required additional map segment. | |
266 | * | |
267 | * An attempt to use this on 'swapmap' will result in | |
268 | * a failure return. This is due mainly to laziness and could be fixed | |
269 | * to do the right thing, although it probably will never be used. | |
270 | */ | |
271 | rmget(mp, size, addr) | |
272 | register struct map *mp; | |
273 | { | |
274 | register struct mapent *ep = (struct mapent *)(mp+1); | |
275 | register struct mapent *bp, *bp2; | |
276 | ||
277 | if (size <= 0) | |
278 | panic("rmget"); | |
279 | if (mp == swapmap) | |
280 | return (0); | |
281 | /* | |
282 | * Look for a map segment containing the requested address. | |
283 | * If none found, return failure. | |
284 | */ | |
285 | for (bp = ep; bp->m_size; bp++) | |
286 | if (bp->m_addr <= addr && bp->m_addr + bp->m_size > addr) | |
287 | break; | |
288 | if (bp->m_size == 0) | |
289 | return (0); | |
290 | ||
291 | /* | |
292 | * If segment is too small, return failure. | |
293 | * If big enough, allocate the block, compressing or expanding | |
294 | * the map as necessary. | |
295 | */ | |
296 | if (bp->m_addr + bp->m_size < addr + size) | |
297 | return (0); | |
298 | if (bp->m_addr == addr) | |
299 | if (bp->m_addr + bp->m_size == addr + size) { | |
300 | /* | |
301 | * Allocate entire segment and compress map | |
302 | */ | |
303 | bp2 = bp; | |
304 | while (bp2->m_size) { | |
305 | bp2++; | |
306 | (bp2-1)->m_addr = bp2->m_addr; | |
307 | (bp2-1)->m_size = bp2->m_size; | |
308 | } | |
309 | } else { | |
310 | /* | |
311 | * Allocate first part of segment | |
312 | */ | |
313 | bp->m_addr += size; | |
314 | bp->m_size -= size; | |
315 | } | |
316 | else | |
317 | if (bp->m_addr + bp->m_size == addr + size) { | |
318 | /* | |
319 | * Allocate last part of segment | |
320 | */ | |
321 | bp->m_size -= size; | |
322 | } else { | |
323 | /* | |
324 | * Allocate from middle of segment, but only | |
325 | * if table can be expanded. | |
326 | */ | |
327 | for (bp2=bp; bp2->m_size; bp2++) | |
328 | ; | |
93cf8c06 | 329 | if (bp2 + 1 >= mp->m_limit) |
1c1f6ecf BF |
330 | return (0); |
331 | while (bp2 > bp) { | |
332 | (bp2+1)->m_addr = bp2->m_addr; | |
333 | (bp2+1)->m_size = bp2->m_size; | |
334 | bp2--; | |
335 | } | |
336 | (bp+1)->m_addr = addr + size; | |
337 | (bp+1)->m_size = | |
338 | bp->m_addr + bp->m_size - (addr + size); | |
339 | bp->m_size = addr - bp->m_addr; | |
340 | } | |
341 | return (addr); | |
342 | } |