linux/drivers/lightnvm/pblk-cache.c
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   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-cache.c - pblk's write cache
  17 */
  18
  19#include "pblk.h"
  20
  21void pblk_write_to_cache(struct pblk *pblk, struct bio *bio,
  22                                unsigned long flags)
  23{
  24        struct pblk_w_ctx w_ctx;
  25        sector_t lba = pblk_get_lba(bio);
  26        unsigned long start_time;
  27        unsigned int bpos, pos;
  28        int nr_entries = pblk_get_secs(bio);
  29        int i, ret;
  30
  31        start_time = bio_start_io_acct(bio);
  32
  33        /* Update the write buffer head (mem) with the entries that we can
  34         * write. The write in itself cannot fail, so there is no need to
  35         * rollback from here on.
  36         */
  37retry:
  38        ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
  39        switch (ret) {
  40        case NVM_IO_REQUEUE:
  41                io_schedule();
  42                goto retry;
  43        case NVM_IO_ERR:
  44                pblk_pipeline_stop(pblk);
  45                bio_io_error(bio);
  46                goto out;
  47        }
  48
  49        pblk_ppa_set_empty(&w_ctx.ppa);
  50        w_ctx.flags = flags;
  51        if (bio->bi_opf & REQ_PREFLUSH) {
  52                w_ctx.flags |= PBLK_FLUSH_ENTRY;
  53                pblk_write_kick(pblk);
  54        }
  55
  56        if (unlikely(!bio_has_data(bio)))
  57                goto out;
  58
  59        for (i = 0; i < nr_entries; i++) {
  60                void *data = bio_data(bio);
  61
  62                w_ctx.lba = lba + i;
  63
  64                pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
  65                pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
  66
  67                bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
  68        }
  69
  70        atomic64_add(nr_entries, &pblk->user_wa);
  71
  72#ifdef CONFIG_NVM_PBLK_DEBUG
  73        atomic_long_add(nr_entries, &pblk->inflight_writes);
  74        atomic_long_add(nr_entries, &pblk->req_writes);
  75#endif
  76
  77        pblk_rl_inserted(&pblk->rl, nr_entries);
  78
  79out:
  80        bio_end_io_acct(bio, start_time);
  81        pblk_write_should_kick(pblk);
  82
  83        if (ret == NVM_IO_DONE)
  84                bio_endio(bio);
  85}
  86
  87/*
  88 * On GC the incoming lbas are not necessarily sequential. Also, some of the
  89 * lbas might not be valid entries, which are marked as empty by the GC thread
  90 */
  91int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
  92{
  93        struct pblk_w_ctx w_ctx;
  94        unsigned int bpos, pos;
  95        void *data = gc_rq->data;
  96        int i, valid_entries;
  97
  98        /* Update the write buffer head (mem) with the entries that we can
  99         * write. The write in itself cannot fail, so there is no need to
 100         * rollback from here on.
 101         */
 102retry:
 103        if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
 104                io_schedule();
 105                goto retry;
 106        }
 107
 108        w_ctx.flags = PBLK_IOTYPE_GC;
 109        pblk_ppa_set_empty(&w_ctx.ppa);
 110
 111        for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
 112                if (gc_rq->lba_list[i] == ADDR_EMPTY)
 113                        continue;
 114
 115                w_ctx.lba = gc_rq->lba_list[i];
 116
 117                pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
 118                pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
 119                                                gc_rq->paddr_list[i], pos);
 120
 121                data += PBLK_EXPOSED_PAGE_SIZE;
 122                valid_entries++;
 123        }
 124
 125        WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
 126                                        "pblk: inconsistent GC write\n");
 127
 128        atomic64_add(valid_entries, &pblk->gc_wa);
 129
 130#ifdef CONFIG_NVM_PBLK_DEBUG
 131        atomic_long_add(valid_entries, &pblk->inflight_writes);
 132        atomic_long_add(valid_entries, &pblk->recov_gc_writes);
 133#endif
 134
 135        pblk_write_should_kick(pblk);
 136        return NVM_IO_OK;
 137}
 138