/* * Copyright (c) 2012 Linutronix GmbH * Copyright (c) 2014 sigma star gmbh * Author: Richard Weinberger <richard@nod.at> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU General Public License for more details. * */ /** * update_fastmap_work_fn - calls ubi_update_fastmap from a work queue * @wrk: the work description object */ static void update_fastmap_work_fn(struct work_struct *wrk) { struct ubi_device *ubi = container_of(wrk, struct ubi_device, fm_work); ubi_update_fastmap(ubi); spin_lock(&ubi->wl_lock); ubi->fm_work_scheduled = 0; spin_unlock(&ubi->wl_lock); } /** * find_anchor_wl_entry - find wear-leveling entry to used as anchor PEB. * @root: the RB-tree where to look for */ static struct ubi_wl_entry *find_anchor_wl_entry(struct rb_root *root) { struct rb_node *p; struct ubi_wl_entry *e, *victim = NULL; int max_ec = UBI_MAX_ERASECOUNTER; ubi_rb_for_each_entry(p, e, root, u.rb) { if (e->pnum < UBI_FM_MAX_START && e->ec < max_ec) { victim = e; max_ec = e->ec; } } return victim; } /** * return_unused_pool_pebs - returns unused PEB to the free tree. * @ubi: UBI device description object * @pool: fastmap pool description object */ static void return_unused_pool_pebs(struct ubi_device *ubi, struct ubi_fm_pool *pool) { int i; struct ubi_wl_entry *e; for (i = pool->used; i < pool->size; i++) { e = ubi->lookuptbl[pool->pebs[i]]; wl_tree_add(e, &ubi->free); ubi->free_count++; } } static int anchor_pebs_avalible(struct rb_root *root) { struct rb_node *p; struct ubi_wl_entry *e; ubi_rb_for_each_entry(p, e, root, u.rb) if (e->pnum < UBI_FM_MAX_START) return 1; return 0; } /** * ubi_wl_get_fm_peb - find a physical erase block with a given maximal number. * @ubi: UBI device description object * @anchor: This PEB will be used as anchor PEB by fastmap * * The function returns a physical erase block with a given maximal number * and removes it from the wl subsystem. * Must be called with wl_lock held! */ struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor) { struct ubi_wl_entry *e = NULL; if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 1)) goto out; if (anchor) e = find_anchor_wl_entry(&ubi->free); else e = find_mean_wl_entry(ubi, &ubi->free); if (!e) goto out; self_check_in_wl_tree(ubi, e, &ubi->free); /* remove it from the free list, * the wl subsystem does no longer know this erase block */ rb_erase(&e->u.rb, &ubi->free); ubi->free_count--; out: return e; } /** * ubi_refill_pools - refills all fastmap PEB pools. * @ubi: UBI device description object */ void ubi_refill_pools(struct ubi_device *ubi) { struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool; struct ubi_fm_pool *pool = &ubi->fm_pool; struct ubi_wl_entry *e; int enough; spin_lock(&ubi->wl_lock); return_unused_pool_pebs(ubi, wl_pool); return_unused_pool_pebs(ubi, pool); wl_pool->size = 0; pool->size = 0; for (;;) { enough = 0; if (pool->size < pool->max_size) { if (!ubi->free.rb_node) break; e = wl_get_wle(ubi); if (!e) break; pool->pebs[pool->size] = e->pnum; pool->size++; } else enough++; if (wl_pool->size < wl_pool->max_size) { if (!ubi->free.rb_node || (ubi->free_count - ubi->beb_rsvd_pebs < 5)) break; e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF); self_check_in_wl_tree(ubi, e, &ubi->free); rb_erase(&e->u.rb, &ubi->free); ubi->free_count--; wl_pool->pebs[wl_pool->size] = e->pnum; wl_pool->size++; } else enough++; if (enough == 2) break; } wl_pool->used = 0; pool->used = 0; spin_unlock(&ubi->wl_lock); } /** * ubi_wl_get_peb - get a physical eraseblock. * @ubi: UBI device description object * * This function returns a physical eraseblock in case of success and a * negative error code in case of failure. * Returns with ubi->fm_eba_sem held in read mode! */ int ubi_wl_get_peb(struct ubi_device *ubi) { int ret, retried = 0; struct ubi_fm_pool *pool = &ubi->fm_pool; struct ubi_fm_pool *wl_pool = &ubi->fm_wl_pool; again: down_read(&ubi->fm_eba_sem); spin_lock(&ubi->wl_lock); /* We check here also for the WL pool because at this point we can * refill the WL pool synchronous. */ if (pool->used == pool->size || wl_pool->used == wl_pool->size) { spin_unlock(&ubi->wl_lock); up_read(&ubi->fm_eba_sem); ret = ubi_update_fastmap(ubi); if (ret) { ubi_msg(ubi, "Unable to write a new fastmap: %i", ret); down_read(&ubi->fm_eba_sem); return -ENOSPC; } down_read(&ubi->fm_eba_sem); spin_lock(&ubi->wl_lock); } if (pool->used == pool->size) { spin_unlock(&ubi->wl_lock); if (retried) { ubi_err(ubi, "Unable to get a free PEB from user WL pool"); ret = -ENOSPC; goto out; } retried = 1; up_read(&ubi->fm_eba_sem); goto again; } ubi_assert(pool->used < pool->size); ret = pool->pebs[pool->used++]; prot_queue_add(ubi, ubi->lookuptbl[ret]); spin_unlock(&ubi->wl_lock); out: return ret; } /* get_peb_for_wl - returns a PEB to be used internally by the WL sub-system. * * @ubi: UBI device description object */ static struct ubi_wl_entry *get_peb_for_wl(struct ubi_device *ubi) { struct ubi_fm_pool *pool = &ubi->fm_wl_pool; int pnum; if (pool->used == pool->size) { /* We cannot update the fastmap here because this * function is called in atomic context. * Let's fail here and refill/update it as soon as possible. */ if (!ubi->fm_work_scheduled) { ubi->fm_work_scheduled = 1; schedule_work(&ubi->fm_work); } return NULL; } pnum = pool->pebs[pool->used++]; return ubi->lookuptbl[pnum]; } /** * ubi_ensure_anchor_pebs - schedule wear-leveling to produce an anchor PEB. * @ubi: UBI device description object */ int ubi_ensure_anchor_pebs(struct ubi_device *ubi) { struct ubi_work *wrk; spin_lock(&ubi->wl_lock); if (ubi->wl_scheduled) { spin_unlock(&ubi->wl_lock); return 0; } ubi->wl_scheduled = 1; spin_unlock(&ubi->wl_lock); wrk = kmalloc(sizeof(struct ubi_work), GFP_NOFS); if (!wrk) { spin_lock(&ubi->wl_lock); ubi->wl_scheduled = 0; spin_unlock(&ubi->wl_lock); return -ENOMEM; } wrk->anchor = 1; wrk->func = &wear_leveling_worker; schedule_ubi_work(ubi, wrk); return 0; } /** * ubi_wl_put_fm_peb - returns a PEB used in a fastmap to the wear-leveling * sub-system. * see: ubi_wl_put_peb() * * @ubi: UBI device description object * @fm_e: physical eraseblock to return * @lnum: the last used logical eraseblock number for the PEB * @torture: if this physical eraseblock has to be tortured */ int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *fm_e, int lnum, int torture) { struct ubi_wl_entry *e; int vol_id, pnum = fm_e->pnum; dbg_wl("PEB %d", pnum); ubi_assert(pnum >= 0); ubi_assert(pnum < ubi->peb_count); spin_lock(&ubi->wl_lock); e = ubi->lookuptbl[pnum]; /* This can happen if we recovered from a fastmap the very * first time and writing now a new one. In this case the wl system * has never seen any PEB used by the original fastmap. */ if (!e) { e = fm_e; ubi_assert(e->ec >= 0); ubi->lookuptbl[pnum] = e; } spin_unlock(&ubi->wl_lock); vol_id = lnum ? UBI_FM_DATA_VOLUME_ID : UBI_FM_SB_VOLUME_ID; return schedule_erase(ubi, e, vol_id, lnum, torture); } /** * ubi_is_erase_work - checks whether a work is erase work. * @wrk: The work object to be checked */ int ubi_is_erase_work(struct ubi_work *wrk) { return wrk->func == erase_worker; } static void ubi_fastmap_close(struct ubi_device *ubi) { int i; flush_work(&ubi->fm_work); return_unused_pool_pebs(ubi, &ubi->fm_pool); return_unused_pool_pebs(ubi, &ubi->fm_wl_pool); if (ubi->fm) { for (i = 0; i < ubi->fm->used_blocks; i++) kfree(ubi->fm->e[i]); } kfree(ubi->fm); } /** * may_reserve_for_fm - tests whether a PEB shall be reserved for fastmap. * See find_mean_wl_entry() * * @ubi: UBI device description object * @e: physical eraseblock to return * @root: RB tree to test against. */ static struct ubi_wl_entry *may_reserve_for_fm(struct ubi_device *ubi, struct ubi_wl_entry *e, struct rb_root *root) { if (e && !ubi->fm_disabled && !ubi->fm && e->pnum < UBI_FM_MAX_START) e = rb_entry(rb_next(root->rb_node), struct ubi_wl_entry, u.rb); return e; }