drivers/lightnvm/pblk-map.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2016 CNEX Labs
   4  * Initial release: Javier Gonzalez <javier@cnexlabs.com>
   5  *                  Matias Bjorling <matias@cnexlabs.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License version
   9  * 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * pblk-map.c - pblk's lba-ppa mapping strategy
  17  *
  18  */
  19
  20 #include "pblk.h"
  21
  22 static int pblk_map_page_data(struct pblk *pblk, unsigned int sentry,
  23                               struct ppa_addr *ppa_list,
  24                               unsigned long *lun_bitmap,
  25                               struct pblk_sec_meta *meta_list,
  26                               unsigned int valid_secs)
  27 {
  28         struct pblk_line *line = pblk_line_get_data(pblk);
  29         struct pblk_emeta *emeta;
  30         struct pblk_w_ctx *w_ctx;
  31         __le64 *lba_list;
  32         u64 paddr;
  33         int nr_secs = pblk->min_write_pgs;
  34         int i;
  35
  36         if (pblk_line_is_full(line)) {
  37                 struct pblk_line *prev_line = line;
  38
  39                 /* If we cannot allocate a new line, make sure to store metadata
  40                  * on current line and then fail
  41                  */
  42                 line = pblk_line_replace_data(pblk);
  43                 pblk_line_close_meta(pblk, prev_line);
  44
  45                 if (!line)
  46                         return -EINTR;
  47         }
  48
  49         emeta = line->emeta;
  50         lba_list = emeta_to_lbas(pblk, emeta->buf);
  51
  52         paddr = pblk_alloc_page(pblk, line, nr_secs);
  53
  54         for (i = 0; i < nr_secs; i++, paddr++) {
  55                 __le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
  56
  57                 /* ppa to be sent to the device */
  58                 ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
  59
  60                 /* Write context for target bio completion on write buffer. Note
  61                  * that the write buffer is protected by the sync backpointer,
  62                  * and a single writer thread have access to each specific entry
  63                  * at a time. Thus, it is safe to modify the context for the
  64                  * entry we are setting up for submission without taking any
  65                  * lock or memory barrier.
  66                  */
  67                 if (i < valid_secs) {
  68                         kref_get(&line->ref);
  69                         w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
  70                         w_ctx->ppa = ppa_list[i];
  71                         meta_list[i].lba = cpu_to_le64(w_ctx->lba);
  72                         lba_list[paddr] = cpu_to_le64(w_ctx->lba);
  73                         if (lba_list[paddr] != addr_empty)
  74                                 line->nr_valid_lbas++;
  75                         else
  76                                 atomic64_inc(&pblk->pad_wa);
  77                 } else {
  78                         lba_list[paddr] = meta_list[i].lba = addr_empty;
  79                         __pblk_map_invalidate(pblk, line, paddr);
  80                 }
  81         }
  82
  83         pblk_down_rq(pblk, ppa_list[0], lun_bitmap);
  84         return 0;
  85 }
  86
  87 void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
  88                  unsigned long *lun_bitmap, unsigned int valid_secs,
  89                  unsigned int off)
  90 {
  91         struct pblk_sec_meta *meta_list = rqd->meta_list;
  92         struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd);
  93         unsigned int map_secs;
  94         int min = pblk->min_write_pgs;
  95         int i;
  96
  97         for (i = off; i < rqd->nr_ppas; i += min) {
  98                 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
  99                 if (pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
 100                                         lun_bitmap, &meta_list[i], map_secs)) {
 101                         bio_put(rqd->bio);
 102                         pblk_free_rqd(pblk, rqd, PBLK_WRITE);
 103                         pblk_pipeline_stop(pblk);
 104                 }
 105         }
 106 }
 107
 108 /* only if erase_ppa is set, acquire erase semaphore */
 109 void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
 110                        unsigned int sentry, unsigned long *lun_bitmap,
 111                        unsigned int valid_secs, struct ppa_addr *erase_ppa)
 112 {
 113         struct nvm_tgt_dev *dev = pblk->dev;
 114         struct nvm_geo *geo = &dev->geo;
 115         struct pblk_line_meta *lm = &pblk->lm;
 116         struct pblk_sec_meta *meta_list = rqd->meta_list;
 117         struct ppa_addr *ppa_list = nvm_rq_to_ppa_list(rqd);
 118         struct pblk_line *e_line, *d_line;
 119         unsigned int map_secs;
 120         int min = pblk->min_write_pgs;
 121         int i, erase_lun;
 122
 123         for (i = 0; i < rqd->nr_ppas; i += min) {
 124                 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
 125                 if (pblk_map_page_data(pblk, sentry + i, &ppa_list[i],
 126                                         lun_bitmap, &meta_list[i], map_secs)) {
 127                         bio_put(rqd->bio);
 128                         pblk_free_rqd(pblk, rqd, PBLK_WRITE);
 129                         pblk_pipeline_stop(pblk);
 130                 }
 131
 132                 erase_lun = pblk_ppa_to_pos(geo, ppa_list[i]);
 133
 134                 /* line can change after page map. We might also be writing the
 135                  * last line.
 136                  */
 137                 e_line = pblk_line_get_erase(pblk);
 138                 if (!e_line)
 139                         return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
 140                                                         valid_secs, i + min);
 141
 142                 spin_lock(&e_line->lock);
 143                 if (!test_bit(erase_lun, e_line->erase_bitmap)) {
 144                         set_bit(erase_lun, e_line->erase_bitmap);
 145                         atomic_dec(&e_line->left_eblks);
 146
 147                         *erase_ppa = ppa_list[i];
 148                         erase_ppa->a.blk = e_line->id;
 149
 150                         spin_unlock(&e_line->lock);
 151
 152                         /* Avoid evaluating e_line->left_eblks */
 153                         return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
 154                                                         valid_secs, i + min);
 155                 }
 156                 spin_unlock(&e_line->lock);
 157         }
 158
 159         d_line = pblk_line_get_data(pblk);
 160
 161         /* line can change after page map. We might also be writing the
 162          * last line.
 163          */
 164         e_line = pblk_line_get_erase(pblk);
 165         if (!e_line)
 166                 return;
 167
 168         /* Erase blocks that are bad in this line but might not be in next */
 169         if (unlikely(pblk_ppa_empty(*erase_ppa)) &&
 170                         bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
 171                 int bit = -1;
 172
 173 retry:
 174                 bit = find_next_bit(d_line->blk_bitmap,
 175                                                 lm->blk_per_line, bit + 1);
 176                 if (bit >= lm->blk_per_line)
 177                         return;
 178
 179                 spin_lock(&e_line->lock);
 180                 if (test_bit(bit, e_line->erase_bitmap)) {
 181                         spin_unlock(&e_line->lock);
 182                         goto retry;
 183                 }
 184                 spin_unlock(&e_line->lock);
 185
 186                 set_bit(bit, e_line->erase_bitmap);
 187                 atomic_dec(&e_line->left_eblks);
 188                 *erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
 189                 erase_ppa->a.blk = e_line->id;
 190         }
 191 }