/* Simple round-robin Logical to physical address translation.
*
* Retrieve the mapping using the active append point. Then update the ap for
* the next write to the disk.
*
* Returns rrpc_addr with the physical address and block. Remember to return to
* rrpc->addr_cache when request is finished.
*/
static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
int is_gc)
{
struct rrpc_lun *rlun;
struct rrpc_block *rblk;
struct nvm_lun *lun;
u64 paddr;
rlun = rrpc_get_lun_rr(rrpc, is_gc);
lun = rlun->parent;
if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
return NULL;
spin_lock(&rlun->lock);
rblk = rlun->cur;
retry:
paddr = rrpc_alloc_addr(rrpc, rblk);
if (paddr == ADDR_EMPTY) {
rblk = rrpc_get_blk(rrpc, rlun, 0);
if (rblk) {
rrpc_set_lun_cur(rlun, rblk);
goto retry;
}
if (is_gc) {
/* retry from emergency gc block */
paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
if (paddr == ADDR_EMPTY) {
rblk = rrpc_get_blk(rrpc, rlun, 1);
if (!rblk) {
pr_err("rrpc: no more blocks");
goto err;
}
rlun->gc_cur = rblk;
paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
}
rblk = rlun->gc_cur;
}
}
spin_unlock(&rlun->lock);
return rrpc_update_map(rrpc, laddr, rblk, paddr);
err:
spin_unlock(&rlun->lock);
return NULL;
}
/* Map logical address to a physical page. The mapping implements a round robin
* approach and allocates a page from the next lun available.
*
* Returns rrpc_addr with the physical address and block. Returns NULL if no
* blocks in the next rlun are available.
*/
static struct ppa_addr rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
int is_gc)
{
struct nvm_tgt_dev *tgt_dev = rrpc->dev;
struct rrpc_lun *rlun;
struct rrpc_block *rblk, **cur_rblk;
struct rrpc_addr *p;
struct ppa_addr ppa;
u64 paddr;
int gc_force = 0;
ppa.ppa = ADDR_EMPTY;
rlun = rrpc_get_lun_rr(rrpc, is_gc);
if (!is_gc && rlun->nr_free_blocks < rrpc->nr_luns * 4)
return ppa;
/*
* page allocation steps:
* 1. Try to allocate new page from current rblk
* 2a. If succeed, proceed to map it in and return
* 2b. If fail, first try to allocate a new block from media manger,
* and then retry step 1. Retry until the normal block pool is
* exhausted.
* 3. If exhausted, and garbage collector is requesting the block,
* go to the reserved block and retry step 1.
* In the case that this fails as well, or it is not GC
* requesting, report not able to retrieve a block and let the
* caller handle further processing.
*/
spin_lock(&rlun->lock);
cur_rblk = &rlun->cur;
rblk = rlun->cur;
retry:
paddr = rrpc_alloc_addr(rrpc, rblk);
if (paddr != ADDR_EMPTY)
goto done;
if (!list_empty(&rlun->wblk_list)) {
new_blk:
rblk = list_first_entry(&rlun->wblk_list, struct rrpc_block,
prio);
rrpc_set_lun_cur(rlun, rblk, cur_rblk);
list_del(&rblk->prio);
goto retry;
}
