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 = line->emeta;
  29         struct pblk_w_ctx *w_ctx;
  30         __le64 *lba_list = emeta_to_lbas(pblk, emeta->buf);
  31         u64 paddr;
  32         int nr_secs = pblk->min_write_pgs;
  33         int i;
  34
  35         paddr = pblk_alloc_page(pblk, line, nr_secs);
  36
  37         for (i = 0; i < nr_secs; i++, paddr++) {
  38                 /* ppa to be sent to the device */
  39                 ppa_list[i] = addr_to_gen_ppa(pblk, paddr, line->id);
  40
  41                 /* Write context for target bio completion on write buffer. Note
  42                  * that the write buffer is protected by the sync backpointer,
  43                  * and a single writer thread have access to each specific entry
  44                  * at a time. Thus, it is safe to modify the context for the
  45                  * entry we are setting up for submission without taking any
  46                  * lock or memory barrier.
  47                  */
  48                 if (i < valid_secs) {
  49                         kref_get(&line->ref);
  50                         w_ctx = pblk_rb_w_ctx(&pblk->rwb, sentry + i);
  51                         w_ctx->ppa = ppa_list[i];
  52                         meta_list[i].lba = cpu_to_le64(w_ctx->lba);
  53                         lba_list[paddr] = cpu_to_le64(w_ctx->lba);
  54                         line->nr_valid_lbas++;
  55                 } else {
  56                         __le64 addr_empty = cpu_to_le64(ADDR_EMPTY);
  57
  58                         lba_list[paddr] = meta_list[i].lba = addr_empty;
  59                         __pblk_map_invalidate(pblk, line, paddr);
  60                 }
  61         }
  62
  63         if (pblk_line_is_full(line)) {
  64                 struct pblk_line *prev_line = line;
  65
  66                 pblk_line_replace_data(pblk);
  67                 pblk_line_close_meta(pblk, prev_line);
  68         }
  69
  70         pblk_down_rq(pblk, ppa_list, nr_secs, lun_bitmap);
  71 }
  72
  73 void pblk_map_rq(struct pblk *pblk, struct nvm_rq *rqd, unsigned int sentry,
  74                  unsigned long *lun_bitmap, unsigned int valid_secs,
  75                  unsigned int off)
  76 {
  77         struct pblk_sec_meta *meta_list = rqd->meta_list;
  78         unsigned int map_secs;
  79         int min = pblk->min_write_pgs;
  80         int i;
  81
  82         for (i = off; i < rqd->nr_ppas; i += min) {
  83                 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
  84                 pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
  85                                         lun_bitmap, &meta_list[i], map_secs);
  86         }
  87 }
  88
  89 /* only if erase_ppa is set, acquire erase semaphore */
  90 void pblk_map_erase_rq(struct pblk *pblk, struct nvm_rq *rqd,
  91                        unsigned int sentry, unsigned long *lun_bitmap,
  92                        unsigned int valid_secs, struct ppa_addr *erase_ppa)
  93 {
  94         struct nvm_tgt_dev *dev = pblk->dev;
  95         struct nvm_geo *geo = &dev->geo;
  96         struct pblk_line_meta *lm = &pblk->lm;
  97         struct pblk_sec_meta *meta_list = rqd->meta_list;
  98         struct pblk_line *e_line, *d_line;
  99         unsigned int map_secs;
 100         int min = pblk->min_write_pgs;
 101         int i, erase_lun;
 102
 103         for (i = 0; i < rqd->nr_ppas; i += min) {
 104                 map_secs = (i + min > valid_secs) ? (valid_secs % min) : min;
 105                 pblk_map_page_data(pblk, sentry + i, &rqd->ppa_list[i],
 106                                         lun_bitmap, &meta_list[i], map_secs);
 107
 108                 erase_lun = pblk_ppa_to_pos(geo, rqd->ppa_list[i]);
 109
 110                 /* line can change after page map. We might also be writing the
 111                  * last line.
 112                  */
 113                 e_line = pblk_line_get_erase(pblk);
 114                 if (!e_line)
 115                         return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
 116                                                         valid_secs, i + min);
 117
 118                 spin_lock(&e_line->lock);
 119                 if (!test_bit(erase_lun, e_line->erase_bitmap)) {
 120                         set_bit(erase_lun, e_line->erase_bitmap);
 121                         atomic_dec(&e_line->left_eblks);
 122
 123                         *erase_ppa = rqd->ppa_list[i];
 124                         erase_ppa->g.blk = e_line->id;
 125
 126                         spin_unlock(&e_line->lock);
 127
 128                         /* Avoid evaluating e_line->left_eblks */
 129                         return pblk_map_rq(pblk, rqd, sentry, lun_bitmap,
 130                                                         valid_secs, i + min);
 131                 }
 132                 spin_unlock(&e_line->lock);
 133         }
 134
 135         d_line = pblk_line_get_data(pblk);
 136
 137         /* line can change after page map. We might also be writing the
 138          * last line.
 139          */
 140         e_line = pblk_line_get_erase(pblk);
 141         if (!e_line)
 142                 return;
 143
 144         /* Erase blocks that are bad in this line but might not be in next */
 145         if (unlikely(ppa_empty(*erase_ppa)) &&
 146                         bitmap_weight(d_line->blk_bitmap, lm->blk_per_line)) {
 147                 int bit = -1;
 148
 149 retry:
 150                 bit = find_next_bit(d_line->blk_bitmap,
 151                                                 lm->blk_per_line, bit + 1);
 152                 if (bit >= lm->blk_per_line)
 153                         return;
 154
 155                 spin_lock(&e_line->lock);
 156                 if (test_bit(bit, e_line->erase_bitmap)) {
 157                         spin_unlock(&e_line->lock);
 158                         goto retry;
 159                 }
 160                 spin_unlock(&e_line->lock);
 161
 162                 set_bit(bit, e_line->erase_bitmap);
 163                 atomic_dec(&e_line->left_eblks);
 164                 *erase_ppa = pblk->luns[bit].bppa; /* set ch and lun */
 165                 erase_ppa->g.blk = e_line->id;
 166         }
 167 }