2 * Copyright (c) 2012 Linutronix GmbH
3 * Copyright (c) 2014 sigma star gmbh
4 * Author: Richard Weinberger <richard@nod.at>
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; version 2.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
18 * update_fastmap_work_fn - calls ubi_update_fastmap from a work queue
19 * @wrk: the work description object
21 static void update_fastmap_work_fn(struct work_struct *wrk)
23 struct ubi_device *ubi = container_of(wrk, struct ubi_device, fm_work);
25 ubi_update_fastmap(ubi);
26 spin_lock(&ubi->wl_lock);
27 ubi->fm_work_scheduled = 0;
28 spin_unlock(&ubi->wl_lock);
32 * find_anchor_wl_entry - find wear-leveling entry to used as anchor PEB.
33 * @root: the RB-tree where to look for
35 static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root)
38 struct ubi_wl_entry *e, *victim = NULL;
39 int max_ec = UBI_MAX_ERASECOUNTER;
41 ubi_rb_for_each_entry(p, e, root, u.rb) {
42 if (e->pnum < UBI_FM_MAX_START && e->ec < max_ec) {
51 static inline void return_unused_peb(struct ubi_device *ubi,
52 struct ubi_wl_entry *e)
54 wl_tree_add(e, &ubi->free);
59 * return_unused_pool_pebs - returns unused PEB to the free tree.
60 * @ubi: UBI device description object
61 * @pool: fastmap pool description object
63 static void return_unused_pool_pebs(struct ubi_device *ubi,
64 struct ubi_fm_pool *pool)
67 struct ubi_wl_entry *e;
69 for (i = pool->used; i < pool->size; i++) {
70 e = ubi->lookuptbl[pool->pebs[i]];
71 return_unused_peb(ubi, e);
76 * ubi_wl_get_fm_peb - find a physical erase block with a given maximal number.
77 * @ubi: UBI device description object
78 * @anchor: This PEB will be used as anchor PEB by fastmap
80 * The function returns a physical erase block with a given maximal number
81 * and removes it from the wl subsystem.
82 * Must be called with wl_lock held!
84 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor)
86 struct ubi_wl_entry *e = NULL;
88 if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 1))
92 e = find_anchor_wl_entry(&ubi->free);
94 e = find_mean_wl_entry(ubi, &ubi->free);
99 self_check_in_wl_tree(ubi, e, &ubi->free);
101 /* remove it from the free list,
102 * the wl subsystem does no longer know this erase block */
103 rb_erase(&e->u.rb, &ubi->free);
110 * ubi_refill_pools - refills all fastmap PEB pools.
111 * @ubi: UBI device description object
113 void ubi_refill_pools(struct ubi_device *ubi)
115 struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
116 struct ubi_fm_pool *pool = &ubi->fm_pool;
117 struct ubi_wl_entry *e;
120 spin_lock(&ubi->wl_lock);
122 return_unused_pool_pebs(ubi, wl_pool);
123 return_unused_pool_pebs(ubi, pool);
130 if (pool->size < pool->max_size) {
131 if (!ubi->free.rb_node)
138 pool->pebs[pool->size] = e->pnum;
143 if (wl_pool->size < wl_pool->max_size) {
144 if (!ubi->free.rb_node ||
145 (ubi->free_count - ubi->beb_rsvd_pebs < 5))
148 e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
149 self_check_in_wl_tree(ubi, e, &ubi->free);
150 rb_erase(&e->u.rb, &ubi->free);
153 wl_pool->pebs[wl_pool->size] = e->pnum;
165 spin_unlock(&ubi->wl_lock);
169 * produce_free_peb - produce a free physical eraseblock.
170 * @ubi: UBI device description object
172 * This function tries to make a free PEB by means of synchronous execution of
173 * pending works. This may be needed if, for example the background thread is
174 * disabled. Returns zero in case of success and a negative error code in case
177 static int produce_free_peb(struct ubi_device *ubi)
181 while (!ubi->free.rb_node && ubi->works_count) {
182 dbg_wl("do one work synchronously");
193 * ubi_wl_get_peb - get a physical eraseblock.
194 * @ubi: UBI device description object
196 * This function returns a physical eraseblock in case of success and a
197 * negative error code in case of failure.
198 * Returns with ubi->fm_eba_sem held in read mode!
200 int ubi_wl_get_peb(struct ubi_device *ubi)
202 int ret, retried = 0;
203 struct ubi_fm_pool *pool = &ubi->fm_pool;
204 struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool;
207 down_read(&ubi->fm_eba_sem);
208 spin_lock(&ubi->wl_lock);
210 /* We check here also for the WL pool because at this point we can
211 * refill the WL pool synchronous. */
212 if (pool->used == pool->size || wl_pool->used == wl_pool->size) {
213 spin_unlock(&ubi->wl_lock);
214 up_read(&ubi->fm_eba_sem);
215 ret = ubi_update_fastmap(ubi);
217 ubi_msg(ubi, "Unable to write a new fastmap: %i", ret);
218 down_read(&ubi->fm_eba_sem);
221 down_read(&ubi->fm_eba_sem);
222 spin_lock(&ubi->wl_lock);
225 if (pool->used == pool->size) {
226 spin_unlock(&ubi->wl_lock);
228 ubi_err(ubi, "Unable to get a free PEB from user WL pool");
233 up_read(&ubi->fm_eba_sem);
234 ret = produce_free_peb(ubi);
236 down_read(&ubi->fm_eba_sem);
242 ubi_assert(pool->used < pool->size);
243 ret = pool->pebs[pool->used++];
244 prot_queue_add(ubi, ubi->lookuptbl[ret]);
245 spin_unlock(&ubi->wl_lock);
250 /* get_peb_for_wl - returns a PEB to be used internally by the WL sub-system.
252 * @ubi: UBI device description object
254 static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi)
256 struct ubi_fm_pool *pool = &ubi->fm_wl_pool;
259 ubi_assert(rwsem_is_locked(&ubi->fm_eba_sem));
261 if (pool->used == pool->size) {
262 /* We cannot update the fastmap here because this
263 * function is called in atomic context.
264 * Let's fail here and refill/update it as soon as possible. */
265 if (!ubi->fm_work_scheduled) {
266 ubi->fm_work_scheduled = 1;
267 schedule_work(&ubi->fm_work);
272 pnum = pool->pebs[pool->used++];
273 return ubi->lookuptbl[pnum];
277 * ubi_ensure_anchor_pebs - schedule wear-leveling to produce an anchor PEB.
278 * @ubi: UBI device description object
280 int ubi_ensure_anchor_pebs(struct ubi_device *ubi)
282 struct ubi_work *wrk;
283 struct ubi_wl_entry *anchor;
285 spin_lock(&ubi->wl_lock);
287 /* Do we already have an anchor? */
288 if (ubi->fm_anchor) {
289 spin_unlock(&ubi->wl_lock);
293 /* See if we can find an anchor PEB on the list of free PEBs */
294 anchor = ubi_wl_get_fm_peb(ubi, 1);
296 ubi->fm_anchor = anchor;
297 spin_unlock(&ubi->wl_lock);
301 /* No luck, trigger wear leveling to produce a new anchor PEB */
302 ubi->fm_do_produce_anchor = 1;
303 if (ubi->wl_scheduled) {
304 spin_unlock(&ubi->wl_lock);
307 ubi->wl_scheduled = 1;
308 spin_unlock(&ubi->wl_lock);
310 wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS);
312 spin_lock(&ubi->wl_lock);
313 ubi->wl_scheduled = 0;
314 spin_unlock(&ubi->wl_lock);
318 wrk->func = &wear_leveling_worker;
319 __schedule_ubi_work(ubi, wrk);
324 * ubi_wl_put_fm_peb - returns a PEB used in a fastmap to the wear-leveling
326 * see: ubi_wl_put_peb()
328 * @ubi: UBI device description object
329 * @fm_e: physical eraseblock to return
330 * @lnum: the last used logical eraseblock number for the PEB
331 * @torture: if this physical eraseblock has to be tortured
333 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *fm_e,
334 int lnum, int torture)
336 struct ubi_wl_entry *e;
337 int vol_id, pnum = fm_e->pnum;
339 dbg_wl("PEB %d", pnum);
341 ubi_assert(pnum >= 0);
342 ubi_assert(pnum < ubi->peb_count);
344 spin_lock(&ubi->wl_lock);
345 e = ubi->lookuptbl[pnum];
347 /* This can happen if we recovered from a fastmap the very
348 * first time and writing now a new one. In this case the wl system
349 * has never seen any PEB used by the original fastmap.
353 ubi_assert(e->ec >= 0);
354 ubi->lookuptbl[pnum] = e;
357 spin_unlock(&ubi->wl_lock);
359 vol_id = lnum ? UBI_FM_DATA_VOLUME_ID : UBI_FM_SB_VOLUME_ID;
360 return schedule_erase(ubi, e, vol_id, lnum, torture, true);
364 * ubi_is_erase_work - checks whether a work is erase work.
365 * @wrk: The work object to be checked
367 int ubi_is_erase_work(struct ubi_work *wrk)
369 return wrk->func == erase_worker;
372 static void ubi_fastmap_close(struct ubi_device *ubi)
376 return_unused_pool_pebs(ubi, &ubi->fm_pool);
377 return_unused_pool_pebs(ubi, &ubi->fm_wl_pool);
379 if (ubi->fm_anchor) {
380 return_unused_peb(ubi, ubi->fm_anchor);
381 ubi->fm_anchor = NULL;
385 for (i = 0; i < ubi->fm->used_blocks; i++)
386 kfree(ubi->fm->e[i]);
392 * may_reserve_for_fm - tests whether a PEB shall be reserved for fastmap.
393 * See find_mean_wl_entry()
395 * @ubi: UBI device description object
396 * @e: physical eraseblock to return
397 * @root: RB tree to test against.
399 static struct ubi_wl_entry *may_reserve_for_fm(struct ubi_device *ubi,
400 struct ubi_wl_entry *e,
401 struct rb_root *root) {
402 if (e && !ubi->fm_disabled && !ubi->fm &&
403 e->pnum < UBI_FM_MAX_START)
404 e = rb_entry(rb_next(root->rb_node),
405 struct ubi_wl_entry, u.rb);