xref: /openbmc/u-boot/fs/yaffs2/yaffs_allocator.c (revision 282ce645)
1 /*
2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
3  *
4  * Copyright (C) 2002-2011 Aleph One Ltd.
5  *   for Toby Churchill Ltd and Brightstar Engineering
6  *
7  * Created by Charles Manning <charles@aleph1.co.uk>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include "yaffs_allocator.h"
15 #include "yaffs_guts.h"
16 #include "yaffs_trace.h"
17 #include "yportenv.h"
18 
19 /*
20  * Each entry in yaffs_tnode_list and yaffs_obj_list hold blocks
21  * of approx 100 objects that are themn allocated singly.
22  * This is basically a simplified slab allocator.
23  *
24  * We don't use the Linux slab allocator because slab does not allow
25  * us to dump all the objects in one hit when we do a umount and tear
26  * down  all the tnodes and objects. slab requires that we first free
27  * the individual objects.
28  *
29  * Once yaffs has been mainlined I shall try to motivate for a change
30  * to slab to provide the extra features we need here.
31  */
32 
33 struct yaffs_tnode_list {
34 	struct yaffs_tnode_list *next;
35 	struct yaffs_tnode *tnodes;
36 };
37 
38 struct yaffs_obj_list {
39 	struct yaffs_obj_list *next;
40 	struct yaffs_obj *objects;
41 };
42 
43 struct yaffs_allocator {
44 	int n_tnodes_created;
45 	struct yaffs_tnode *free_tnodes;
46 	int n_free_tnodes;
47 	struct yaffs_tnode_list *alloc_tnode_list;
48 
49 	int n_obj_created;
50 	struct list_head free_objs;
51 	int n_free_objects;
52 
53 	struct yaffs_obj_list *allocated_obj_list;
54 };
55 
56 static void yaffs_deinit_raw_tnodes(struct yaffs_dev *dev)
57 {
58 	struct yaffs_allocator *allocator =
59 	    (struct yaffs_allocator *)dev->allocator;
60 	struct yaffs_tnode_list *tmp;
61 
62 	if (!allocator) {
63 		BUG();
64 		return;
65 	}
66 
67 	while (allocator->alloc_tnode_list) {
68 		tmp = allocator->alloc_tnode_list->next;
69 
70 		kfree(allocator->alloc_tnode_list->tnodes);
71 		kfree(allocator->alloc_tnode_list);
72 		allocator->alloc_tnode_list = tmp;
73 	}
74 
75 	allocator->free_tnodes = NULL;
76 	allocator->n_free_tnodes = 0;
77 	allocator->n_tnodes_created = 0;
78 }
79 
80 static void yaffs_init_raw_tnodes(struct yaffs_dev *dev)
81 {
82 	struct yaffs_allocator *allocator = dev->allocator;
83 
84 	if (!allocator) {
85 		BUG();
86 		return;
87 	}
88 
89 	allocator->alloc_tnode_list = NULL;
90 	allocator->free_tnodes = NULL;
91 	allocator->n_free_tnodes = 0;
92 	allocator->n_tnodes_created = 0;
93 }
94 
95 static int yaffs_create_tnodes(struct yaffs_dev *dev, int n_tnodes)
96 {
97 	struct yaffs_allocator *allocator =
98 	    (struct yaffs_allocator *)dev->allocator;
99 	int i;
100 	struct yaffs_tnode *new_tnodes;
101 	u8 *mem;
102 	struct yaffs_tnode *curr;
103 	struct yaffs_tnode *next;
104 	struct yaffs_tnode_list *tnl;
105 
106 	if (!allocator) {
107 		BUG();
108 		return YAFFS_FAIL;
109 	}
110 
111 	if (n_tnodes < 1)
112 		return YAFFS_OK;
113 
114 	/* make these things */
115 	new_tnodes = kmalloc(n_tnodes * dev->tnode_size, GFP_NOFS);
116 	mem = (u8 *) new_tnodes;
117 
118 	if (!new_tnodes) {
119 		yaffs_trace(YAFFS_TRACE_ERROR,
120 			"yaffs: Could not allocate Tnodes");
121 		return YAFFS_FAIL;
122 	}
123 
124 	/* New hookup for wide tnodes */
125 	for (i = 0; i < n_tnodes - 1; i++) {
126 		curr = (struct yaffs_tnode *)&mem[i * dev->tnode_size];
127 		next = (struct yaffs_tnode *)&mem[(i + 1) * dev->tnode_size];
128 		curr->internal[0] = next;
129 	}
130 
131 	curr = (struct yaffs_tnode *)&mem[(n_tnodes - 1) * dev->tnode_size];
132 	curr->internal[0] = allocator->free_tnodes;
133 	allocator->free_tnodes = (struct yaffs_tnode *)mem;
134 
135 	allocator->n_free_tnodes += n_tnodes;
136 	allocator->n_tnodes_created += n_tnodes;
137 
138 	/* Now add this bunch of tnodes to a list for freeing up.
139 	 * NB If we can't add this to the management list it isn't fatal
140 	 * but it just means we can't free this bunch of tnodes later.
141 	 */
142 	tnl = kmalloc(sizeof(struct yaffs_tnode_list), GFP_NOFS);
143 	if (!tnl) {
144 		yaffs_trace(YAFFS_TRACE_ERROR,
145 			"Could not add tnodes to management list");
146 		return YAFFS_FAIL;
147 	} else {
148 		tnl->tnodes = new_tnodes;
149 		tnl->next = allocator->alloc_tnode_list;
150 		allocator->alloc_tnode_list = tnl;
151 	}
152 
153 	yaffs_trace(YAFFS_TRACE_ALLOCATE, "Tnodes added");
154 
155 	return YAFFS_OK;
156 }
157 
158 struct yaffs_tnode *yaffs_alloc_raw_tnode(struct yaffs_dev *dev)
159 {
160 	struct yaffs_allocator *allocator =
161 	    (struct yaffs_allocator *)dev->allocator;
162 	struct yaffs_tnode *tn = NULL;
163 
164 	if (!allocator) {
165 		BUG();
166 		return NULL;
167 	}
168 
169 	/* If there are none left make more */
170 	if (!allocator->free_tnodes)
171 		yaffs_create_tnodes(dev, YAFFS_ALLOCATION_NTNODES);
172 
173 	if (allocator->free_tnodes) {
174 		tn = allocator->free_tnodes;
175 		allocator->free_tnodes = allocator->free_tnodes->internal[0];
176 		allocator->n_free_tnodes--;
177 	}
178 
179 	return tn;
180 }
181 
182 /* FreeTnode frees up a tnode and puts it back on the free list */
183 void yaffs_free_raw_tnode(struct yaffs_dev *dev, struct yaffs_tnode *tn)
184 {
185 	struct yaffs_allocator *allocator = dev->allocator;
186 
187 	if (!allocator) {
188 		BUG();
189 		return;
190 	}
191 
192 	if (tn) {
193 		tn->internal[0] = allocator->free_tnodes;
194 		allocator->free_tnodes = tn;
195 		allocator->n_free_tnodes++;
196 	}
197 	dev->checkpoint_blocks_required = 0;	/* force recalculation */
198 }
199 
200 /*--------------- yaffs_obj alloaction ------------------------
201  *
202  * Free yaffs_objs are stored in a list using obj->siblings.
203  * The blocks of allocated objects are stored in a linked list.
204  */
205 
206 static void yaffs_init_raw_objs(struct yaffs_dev *dev)
207 {
208 	struct yaffs_allocator *allocator = dev->allocator;
209 
210 	if (!allocator) {
211 		BUG();
212 		return;
213 	}
214 
215 	allocator->allocated_obj_list = NULL;
216 	INIT_LIST_HEAD(&allocator->free_objs);
217 	allocator->n_free_objects = 0;
218 }
219 
220 static void yaffs_deinit_raw_objs(struct yaffs_dev *dev)
221 {
222 	struct yaffs_allocator *allocator = dev->allocator;
223 	struct yaffs_obj_list *tmp;
224 
225 	if (!allocator) {
226 		BUG();
227 		return;
228 	}
229 
230 	while (allocator->allocated_obj_list) {
231 		tmp = allocator->allocated_obj_list->next;
232 		kfree(allocator->allocated_obj_list->objects);
233 		kfree(allocator->allocated_obj_list);
234 		allocator->allocated_obj_list = tmp;
235 	}
236 
237 	INIT_LIST_HEAD(&allocator->free_objs);
238 	allocator->n_free_objects = 0;
239 	allocator->n_obj_created = 0;
240 }
241 
242 static int yaffs_create_free_objs(struct yaffs_dev *dev, int n_obj)
243 {
244 	struct yaffs_allocator *allocator = dev->allocator;
245 	int i;
246 	struct yaffs_obj *new_objs;
247 	struct yaffs_obj_list *list;
248 
249 	if (!allocator) {
250 		BUG();
251 		return YAFFS_FAIL;
252 	}
253 
254 	if (n_obj < 1)
255 		return YAFFS_OK;
256 
257 	/* make these things */
258 	new_objs = kmalloc(n_obj * sizeof(struct yaffs_obj), GFP_NOFS);
259 	list = kmalloc(sizeof(struct yaffs_obj_list), GFP_NOFS);
260 
261 	if (!new_objs || !list) {
262 		kfree(new_objs);
263 		new_objs = NULL;
264 		kfree(list);
265 		list = NULL;
266 		yaffs_trace(YAFFS_TRACE_ALLOCATE,
267 			"Could not allocate more objects");
268 		return YAFFS_FAIL;
269 	}
270 
271 	/* Hook them into the free list */
272 	for (i = 0; i < n_obj; i++)
273 		list_add(&new_objs[i].siblings, &allocator->free_objs);
274 
275 	allocator->n_free_objects += n_obj;
276 	allocator->n_obj_created += n_obj;
277 
278 	/* Now add this bunch of Objects to a list for freeing up. */
279 
280 	list->objects = new_objs;
281 	list->next = allocator->allocated_obj_list;
282 	allocator->allocated_obj_list = list;
283 
284 	return YAFFS_OK;
285 }
286 
287 struct yaffs_obj *yaffs_alloc_raw_obj(struct yaffs_dev *dev)
288 {
289 	struct yaffs_obj *obj = NULL;
290 	struct list_head *lh;
291 	struct yaffs_allocator *allocator = dev->allocator;
292 
293 	if (!allocator) {
294 		BUG();
295 		return obj;
296 	}
297 
298 	/* If there are none left make more */
299 	if (list_empty(&allocator->free_objs))
300 		yaffs_create_free_objs(dev, YAFFS_ALLOCATION_NOBJECTS);
301 
302 	if (!list_empty(&allocator->free_objs)) {
303 		lh = allocator->free_objs.next;
304 		obj = list_entry(lh, struct yaffs_obj, siblings);
305 		list_del_init(lh);
306 		allocator->n_free_objects--;
307 	}
308 
309 	return obj;
310 }
311 
312 void yaffs_free_raw_obj(struct yaffs_dev *dev, struct yaffs_obj *obj)
313 {
314 
315 	struct yaffs_allocator *allocator = dev->allocator;
316 
317 	if (!allocator) {
318 		BUG();
319 		return;
320 	}
321 
322 	/* Link into the free list. */
323 	list_add(&obj->siblings, &allocator->free_objs);
324 	allocator->n_free_objects++;
325 }
326 
327 void yaffs_deinit_raw_tnodes_and_objs(struct yaffs_dev *dev)
328 {
329 
330 	if (!dev->allocator) {
331 		BUG();
332 		return;
333 	}
334 
335 	yaffs_deinit_raw_tnodes(dev);
336 	yaffs_deinit_raw_objs(dev);
337 	kfree(dev->allocator);
338 	dev->allocator = NULL;
339 }
340 
341 void yaffs_init_raw_tnodes_and_objs(struct yaffs_dev *dev)
342 {
343 	struct yaffs_allocator *allocator;
344 
345 	if (dev->allocator) {
346 		BUG();
347 		return;
348 	}
349 
350 	allocator = kmalloc(sizeof(struct yaffs_allocator), GFP_NOFS);
351 	if (allocator) {
352 		dev->allocator = allocator;
353 		yaffs_init_raw_tnodes(dev);
354 		yaffs_init_raw_objs(dev);
355 	}
356 }
357