/*
* Copyright (C) 2016 CNEX Labs
* Initial release: Javier Gonzalez <javier@cnexlabs.com>
* Matias Bjorling <matias@cnexlabs.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* 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.
*
* pblk-map.c - pblk's lba-ppa mapping strategy
*
*/
#include "pblk.h"
static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
struct ppa_addr *ppa_list,
unsigned long *lun_bitmap,
struct pblk_sec_meta *meta_list,
unsigned int valid_secs)
{
struct pblk_line *line = pblk_line_get_data(pblk);
struct pblk_emeta *emeta;
struct pblk_w_ctx *w_ctx;
__le64 *lba_list;
u64 paddr;
int nr_secs = pblk->min_write_pgs;
int i;
if (pblk_line_is_full(line)) {
struct pblk_line *prev_line = line;
/* If we cannot allocate a new line, make sure to store metadata
* on current line and then fail
*/
line = pblk_line_replace_data(pblk);
pblk_line_close_meta(pblk, prev_line);
if (!line)
return -EINTR;
}
emeta = line->emeta;
lba_list = emeta_to_lbas(pblk, emeta->buf);
paddr = pblk_alloc_page(pblk, line, nr_secs);
for (i = 0; i < nr_secs; i++, paddr++) {
__le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
/* ppa to be sent to the device */
ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
/* Write context for target bio completion on write buffer. Note
* that the write buffer is protected by the sync backpointer,
* and a single writer thread have access to each specific entry
* at a time. Thus, it is safe to modify the context for the
* entry we are setting up for submission without taking any
* lock or memory barrier.
*/
if (i < valid_secs) {
kref_get(&line->ref);
w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
w_ctx->ppa = ppa_list[i];
meta_list[i].lba = cpu_to_le64(w_ctx->lba);
lba_list[paddr] = cpu_to_le64(w_ctx->lba);
if (lba_list[paddr] != addr_empty)
line->nr_valid_lbas++;
else
atomic64_inc(&pblk->pad_wa);
} else {
lba_list[paddr] = meta_list[i].lba = addr_empty;
__pblk_map_invalidate(pblk, line, paddr);
}
}
pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
return 0;
}
void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
unsigned long *lun_bitmap, unsigned int valid_secs,
unsigned int off)
{
struct pblk_sec_meta *meta_list = rqd->meta_list;
unsigned int map_secs;
int min = pblk->min_write_pgs;
int i;
for (i = off; i < rqd->nr_ppas; i += min) {
map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
if (pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
lun_bitmap, &meta_list[i], map_secs)) {
bio_put(rqd->bio);
pblk_free_rqd(pblk, rqd, PBLK_WRITE);
pblk_pipeline_stop(pblk);
}
}
}
/* only if erase_ppa is set, acquire erase semaphore */
void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
unsigned int sentry, unsigned long *lun_bitmap,
unsigned int valid_secs, struct ppa_addr *erase_ppa)
{
struct nvm_tgt_dev *dev = pblk->dev;
struct nvm_geo *geo = &dev->geo;
struct pblk_line_meta *lm = &pblk->lm;
struct pblk_sec_meta *meta_list = rqd->meta_list;
struct pblk_line *e_line, *d_line;
unsigned int map_secs;
int min = pblk->min_write_pgs;
int i, erase_lun;
for (i = 0; i < rqd->nr_ppas; i += min) {
map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
if (pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
lun_bitmap, &meta_list[i], map_secs)) {
bio_put(rqd->bio);
pblk_free_rqd(pblk, rqd, PBLK_WRITE);
pblk_pipeline_stop(pblk);
}
erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
/* line can change after page map. We might also be writing the
* last line.
*/
e_line = pblk_line_get_erase(pblk);
if (!e_line)
return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
valid_secs, i + min);
spin_lock(&e_line->lock);
if (!test_bit(erase_lun, e_line->erase_bitmap)) {
set_bit(erase_lun, e_line->erase_bitmap);
atomic_dec(&e_line->left_eblks);
*erase_ppa = rqd->ppa_list[i];
erase_ppa->a.blk = e_line->id;
spin_unlock(&e_line->lock);
/* Avoid evaluating e_line->left_eblks */
return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
valid_secs, i + min);
}
spin_unlock(&e_line->lock);
}
d_line = pblk_line_get_data(pblk);
/* line can change after page map. We might also be writing the
* last line.
*/
e_line = pblk_line_get_erase(pblk);
if (!e_line)
return;
/* Erase blocks that are bad in this line but might not be in next */
if (unlikely(pblk_ppa_empty(*erase_ppa)) &&
bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
int bit = -1;
retry:
bit = find_next_bit(d_line->blk_bitmap,
lm->blk_per_line, bit + 1);
if (bit >= lm->blk_per_line)
return;
spin_lock(&e_line->lock);
if (test_bit(bit, e_line->erase_bitmap)) {
spin_unlock(&e_line->lock);
goto retry;
}
spin_unlock(&e_line->lock);
set_bit(bit, e_line->erase_bitmap);
atomic_dec(&e_line->left_eblks);
*erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
erase_ppa->a.blk = e_line->id;
}
}
