drivers/lightnvm/pblk-map.c

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