drivers/mtd/ubi/wl.c

Source file repositories/reference/linux-study-clean/drivers/mtd/ubi/wl.c

File Facts

System
Linux kernel
Corpus path
drivers/mtd/ubi/wl.c
Extension
.c
Size
58059 bytes
Lines
2179
Domain
Driver Families
Bucket
drivers/mtd
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (e->pnum == e1->pnum) {
			ubi_assert(e == e1);
			return 1;
		}

		if (e->ec < e1->ec)
			p = p->rb_left;
		else if (e->ec > e1->ec)
			p = p->rb_right;
		else {
			ubi_assert(e->pnum != e1->pnum);
			if (e->pnum < e1->pnum)
				p = p->rb_left;
			else
				p = p->rb_right;
		}
	}

	return 0;
}

/**
 * in_pq - check if a wear-leveling entry is present in the protection queue.
 * @ubi: UBI device description object
 * @e: the wear-leveling entry to check
 *
 * This function returns non-zero if @e is in the protection queue and zero
 * if it is not.
 */
static inline int in_pq(const struct ubi_device *ubi, struct ubi_wl_entry *e)
{
	struct ubi_wl_entry *p;
	int i;

	for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i)
		list_for_each_entry(p, &ubi->pq[i], u.list)
			if (p == e)
				return 1;

	return 0;
}

/**
 * prot_queue_add - add physical eraseblock to the protection queue.
 * @ubi: UBI device description object
 * @e: the physical eraseblock to add
 *
 * This function adds @e to the tail of the protection queue @ubi->pq, where
 * @e will stay for %UBI_PROT_QUEUE_LEN erase operations and will be
 * temporarily protected from the wear-leveling worker. Note, @wl->lock has to
 * be locked.
 */
static void prot_queue_add(struct ubi_device *ubi, struct ubi_wl_entry *e)
{
	int pq_tail = ubi->pq_head - 1;

	if (pq_tail < 0)
		pq_tail = UBI_PROT_QUEUE_LEN - 1;
	ubi_assert(pq_tail >= 0 && pq_tail < UBI_PROT_QUEUE_LEN);
	list_add_tail(&e->u.list, &ubi->pq[pq_tail]);
	dbg_wl("added PEB %d EC %d to the protection queue", e->pnum, e->ec);
}

/**
 * find_wl_entry - find wear-leveling entry closest to certain erase counter.
 * @ubi: UBI device description object
 * @root: the RB-tree where to look for
 * @diff: maximum possible difference from the smallest erase counter
 * @pick_max: pick PEB even its erase counter beyonds 'min_ec + @diff'
 *
 * This function looks for a wear leveling entry with erase counter closest to
 * min + @diff, where min is the smallest erase counter.
 */
static struct ubi_wl_entry *find_wl_entry(struct ubi_device *ubi,
					  struct rb_root *root, int diff,
					  int pick_max)
{
	struct rb_node *p;
	struct ubi_wl_entry *e;
	int max;

	e = rb_entry(rb_first(root), struct ubi_wl_entry, u.rb);
	max = e->ec + diff;

	p = root->rb_node;
	while (p) {
		struct ubi_wl_entry *e1;

		e1 = rb_entry(p, struct ubi_wl_entry, u.rb);
		if (e1->ec >= max) {

Annotation

Implementation Notes