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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/mtd/ubi/fastmap-wl.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/mtd/ubi/fastmap-wl.c')
-rw-r--r--drivers/mtd/ubi/fastmap-wl.c490
1 files changed, 490 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/fastmap-wl.c b/drivers/mtd/ubi/fastmap-wl.c
new file mode 100644
index 0000000000..863f571f1a
--- /dev/null
+++ b/drivers/mtd/ubi/fastmap-wl.c
@@ -0,0 +1,490 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012 Linutronix GmbH
+ * Copyright (c) 2014 sigma star gmbh
+ * Author: Richard Weinberger <richard@nod.at>
+ */
+
+/**
+ * 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;
+}
+
+static inline void return_unused_peb(struct ubi_device *ubi,
+ struct ubi_wl_entry *e)
+{
+ wl_tree_add(e, &ubi->free);
+ ubi->free_count++;
+}
+
+/**
+ * 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]];
+ return_unused_peb(ubi, e);
+ }
+}
+
+/**
+ * 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;
+}
+
+/*
+ * has_enough_free_count - whether ubi has enough free pebs to fill fm pools
+ * @ubi: UBI device description object
+ * @is_wl_pool: whether UBI is filling wear leveling pool
+ *
+ * This helper function checks whether there are enough free pebs (deducted
+ * by fastmap pebs) to fill fm_pool and fm_wl_pool, above rule works after
+ * there is at least one of free pebs is filled into fm_wl_pool.
+ * For wear leveling pool, UBI should also reserve free pebs for bad pebs
+ * handling, because there maybe no enough free pebs for user volumes after
+ * producing new bad pebs.
+ */
+static bool has_enough_free_count(struct ubi_device *ubi, bool is_wl_pool)
+{
+ int fm_used = 0; // fastmap non anchor pebs.
+ int beb_rsvd_pebs;
+
+ if (!ubi->free.rb_node)
+ return false;
+
+ beb_rsvd_pebs = is_wl_pool ? ubi->beb_rsvd_pebs : 0;
+ if (ubi->fm_wl_pool.size > 0 && !(ubi->ro_mode || ubi->fm_disabled))
+ fm_used = ubi->fm_size / ubi->leb_size - 1;
+
+ return ubi->free_count - beb_rsvd_pebs > fm_used;
+}
+
+/**
+ * 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;
+
+ if (ubi->fm_anchor) {
+ wl_tree_add(ubi->fm_anchor, &ubi->free);
+ ubi->free_count++;
+ ubi->fm_anchor = NULL;
+ }
+
+ if (!ubi->fm_disabled)
+ /*
+ * All available PEBs are in ubi->free, now is the time to get
+ * the best anchor PEBs.
+ */
+ ubi->fm_anchor = ubi_wl_get_fm_peb(ubi, 1);
+
+ for (;;) {
+ enough = 0;
+ if (pool->size < pool->max_size) {
+ if (!has_enough_free_count(ubi, false))
+ 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 (!has_enough_free_count(ubi, true))
+ 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);
+}
+
+/**
+ * produce_free_peb - produce a free physical eraseblock.
+ * @ubi: UBI device description object
+ *
+ * This function tries to make a free PEB by means of synchronous execution of
+ * pending works. This may be needed if, for example the background thread is
+ * disabled. Returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+static int produce_free_peb(struct ubi_device *ubi)
+{
+ int err;
+
+ while (!ubi->free.rb_node && ubi->works_count) {
+ dbg_wl("do one work synchronously");
+ err = do_work(ubi);
+
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+/**
+ * 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, attempts = 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);
+ attempts++;
+ if (attempts == 10) {
+ ubi_err(ubi, "Unable to get a free PEB from user WL pool");
+ ret = -ENOSPC;
+ goto out;
+ }
+ up_read(&ubi->fm_eba_sem);
+ ret = produce_free_peb(ubi);
+ if (ret < 0) {
+ down_read(&ubi->fm_eba_sem);
+ goto out;
+ }
+ 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;
+}
+
+/**
+ * next_peb_for_wl - returns next PEB to be used internally by the
+ * WL sub-system.
+ *
+ * @ubi: UBI device description object
+ */
+static struct ubi_wl_entry *next_peb_for_wl(struct ubi_device *ubi)
+{
+ struct ubi_fm_pool *pool = &ubi->fm_wl_pool;
+ int pnum;
+
+ if (pool->used == pool->size)
+ return NULL;
+
+ pnum = pool->pebs[pool->used];
+ return ubi->lookuptbl[pnum];
+}
+
+/**
+ * need_wear_leveling - checks whether to trigger a wear leveling work.
+ * UBI fetches free PEB from wl_pool, we check free PEBs from both 'wl_pool'
+ * and 'ubi->free', because free PEB in 'ubi->free' tree maybe moved into
+ * 'wl_pool' by ubi_refill_pools().
+ *
+ * @ubi: UBI device description object
+ */
+static bool need_wear_leveling(struct ubi_device *ubi)
+{
+ int ec;
+ struct ubi_wl_entry *e;
+
+ if (!ubi->used.rb_node)
+ return false;
+
+ e = next_peb_for_wl(ubi);
+ if (!e) {
+ if (!ubi->free.rb_node)
+ return false;
+ e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
+ ec = e->ec;
+ } else {
+ ec = e->ec;
+ if (ubi->free.rb_node) {
+ e = find_wl_entry(ubi, &ubi->free, WL_FREE_MAX_DIFF);
+ ec = max(ec, e->ec);
+ }
+ }
+ e = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
+
+ return ec - e->ec >= UBI_WL_THRESHOLD;
+}
+
+/* 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;
+
+ ubi_assert(rwsem_is_locked(&ubi->fm_eba_sem));
+
+ 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;
+ struct ubi_wl_entry *anchor;
+
+ spin_lock(&ubi->wl_lock);
+
+ /* Do we already have an anchor? */
+ if (ubi->fm_anchor) {
+ spin_unlock(&ubi->wl_lock);
+ return 0;
+ }
+
+ /* See if we can find an anchor PEB on the list of free PEBs */
+ anchor = ubi_wl_get_fm_peb(ubi, 1);
+ if (anchor) {
+ ubi->fm_anchor = anchor;
+ spin_unlock(&ubi->wl_lock);
+ return 0;
+ }
+
+ ubi->fm_do_produce_anchor = 1;
+ /* No luck, trigger wear leveling to produce a new anchor PEB. */
+ 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->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, true);
+}
+
+/**
+ * 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;
+
+ return_unused_pool_pebs(ubi, &ubi->fm_pool);
+ return_unused_pool_pebs(ubi, &ubi->fm_wl_pool);
+
+ if (ubi->fm_anchor) {
+ return_unused_peb(ubi, ubi->fm_anchor);
+ ubi->fm_anchor = NULL;
+ }
+
+ 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;
+}