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 void 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                 line = pblk_line_replace_data(pblk);
  39                 pblk_line_close_meta(pblk, prev_line);
  40         }
  41
  42         emeta = line->emeta;
  43         lba_list = emeta_to_lbas(pblk, emeta->buf);
  44
  45         paddr = pblk_alloc_page(pblk, line, nr_secs);
  46
  47         for (i = 0; i < nr_secs; i++, paddr++) {
  48                 __le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
  49
  50                 /* ppa to be sent to the device */
  51                 ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
  52
  53                 /* Write context for target bio completion on write buffer. Note
  54                  * that the write buffer is protected by the sync backpointer,
  55                  * and a single writer thread have access to each specific entry
  56                  * at a time. Thus, it is safe to modify the context for the
  57                  * entry we are setting up for submission without taking any
  58                  * lock or memory barrier.
  59                  */
  60                 if (i < valid_secs) {
  61                         kref_get(&line->ref);
  62                         w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
  63                         w_ctx->ppa = ppa_list[i];
  64                         meta_list[i].lba = cpu_to_le64(w_ctx->lba);
  65                         lba_list[paddr] = cpu_to_le64(w_ctx->lba);
  66                         if (lba_list[paddr] != addr_empty)
  67                                 line->nr_valid_lbas++;
  68                 } else {
  69                         lba_list[paddr] = meta_list[i].lba = addr_empty;
  70                         __pblk_map_invalidate(pblk, line, paddr);
  71                 }
  72         }
  73
  74         pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
  75 }
  76
  77 void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
  78                  unsigned long *lun_bitmap, unsigned int valid_secs,
  79                  unsigned int off)
  80 {
  81         struct pblk_sec_meta *meta_list = rqd->meta_list;
  82         unsigned int map_secs;
  83         int min = pblk->min_write_pgs;
  84         int i;
  85
  86         for (i = off; i < rqd->nr_ppas; i += min) {
  87                 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
  88                 pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
  89                                         lun_bitmap, &meta_list[i], map_secs);
  90         }
  91 }
  92
  93 /* only if erase_ppa is set, acquire erase semaphore */
  94 void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
  95                        unsigned int sentry, unsigned long *lun_bitmap,
  96                        unsigned int valid_secs, struct ppa_addr *erase_ppa)
  97 {
  98         struct nvm_tgt_dev *dev = pblk->dev;
  99         struct nvm_geo *geo = &dev->geo;
 100         struct pblk_line_meta *lm = &pblk->lm;
 101         struct pblk_sec_meta *meta_list = rqd->meta_list;
 102         struct pblk_line *e_line, *d_line;
 103         unsigned int map_secs;
 104         int min = pblk->min_write_pgs;
 105         int i, erase_lun;
 106
 107         for (i = 0; i < rqd->nr_ppas; i += min) {
 108                 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
 109                 pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
 110                                         lun_bitmap, &meta_list[i], map_secs);
 111
 112                 erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
 113
 114                 /* line can change after page map. We might also be writing the
 115                  * last line.
 116                  */
 117                 e_line = pblk_line_get_erase(pblk);
 118                 if (!e_line)
 119                         return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
 120                                                         valid_secs, i + min);
 121
 122                 spin_lock(&e_line->lock);
 123                 if (!test_bit(erase_lun, e_line->erase_bitmap)) {
 124                         set_bit(erase_lun, e_line->erase_bitmap);
 125                         atomic_dec(&e_line->left_eblks);
 126
 127                         *erase_ppa = rqd->ppa_list[i];
 128                         erase_ppa->g.blk = e_line->id;
 129
 130                         spin_unlock(&e_line->lock);
 131
 132                         /* Avoid evaluating e_line->left_eblks */
 133                         return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
 134                                                         valid_secs, i + min);
 135                 }
 136                 spin_unlock(&e_line->lock);
 137         }
 138
 139         d_line = pblk_line_get_data(pblk);
 140
 141         /* line can change after page map. We might also be writing the
 142          * last line.
 143          */
 144         e_line = pblk_line_get_erase(pblk);
 145         if (!e_line)
 146                 return;
 147
 148         /* Erase blocks that are bad in this line but might not be in next */
 149         if (unlikely(ppa_empty(*erase_ppa)) &&
 150                         bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
 151                 int bit = -1;
 152
 153 retry:
 154                 bit = find_next_bit(d_line->blk_bitmap,
 155                                                 lm->blk_per_line, bit + 1);
 156                 if (bit >= lm->blk_per_line)
 157                         return;
 158
 159                 spin_lock(&e_line->lock);
 160                 if (test_bit(bit, e_line->erase_bitmap)) {
 161                         spin_unlock(&e_line->lock);
 162                         goto retry;
 163                 }
 164                 spin_unlock(&e_line->lock);
 165
 166                 set_bit(bit, e_line->erase_bitmap);
 167                 atomic_dec(&e_line->left_eblks);
 168                 *erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
 169                 erase_ppa->g.blk = e_line->id;
 170         }
 171 }