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 request_queue *q = pblk->dev->q;
 25	struct pblk_w_ctx w_ctx;
 26	sector_t lba = pblk_get_lba(bio);
 27	unsigned long start_time = jiffies;
 28	unsigned int bpos, pos;
 29	int nr_entries = pblk_get_secs(bio);
 30	int i, ret;
 31
 32	generic_start_io_acct(q, REQ_OP_WRITE, bio_sectors(bio),
 33			      &pblk->disk->part0);
 34
 35	/* Update the write buffer head (mem) with the entries that we can
 36	 * write. The write in itself cannot fail, so there is no need to
 37	 * rollback from here on.
 38	 */
 39retry:
 40	ret = pblk_rb_may_write_user(&pblk->rwb, bio, nr_entries, &bpos);
 41	switch (ret) {
 42	case NVM_IO_REQUEUE:
 43		io_schedule();
 44		goto retry;
 45	case NVM_IO_ERR:
 46		pblk_pipeline_stop(pblk);
 47		bio_io_error(bio);
 48		goto out;
 49	}
 50
 51	pblk_ppa_set_empty(&w_ctx.ppa);
 52	w_ctx.flags = flags;
 53	if (bio->bi_opf & REQ_PREFLUSH) {
 54		w_ctx.flags |= PBLK_FLUSH_ENTRY;
 55		pblk_write_kick(pblk);
 56	}
 57
 58	if (unlikely(!bio_has_data(bio)))
 59		goto out;
 60
 61	for (i = 0; i < nr_entries; i++) {
 62		void *data = bio_data(bio);
 63
 64		w_ctx.lba = lba + i;
 65
 66		pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + i);
 67		pblk_rb_write_entry_user(&pblk->rwb, data, w_ctx, pos);
 68
 69		bio_advance(bio, PBLK_EXPOSED_PAGE_SIZE);
 70	}
 71
 72	atomic64_add(nr_entries, &pblk->user_wa);
 73
 74#ifdef CONFIG_NVM_PBLK_DEBUG
 75	atomic_long_add(nr_entries, &pblk->inflight_writes);
 76	atomic_long_add(nr_entries, &pblk->req_writes);
 77#endif
 78
 79	pblk_rl_inserted(&pblk->rl, nr_entries);
 80
 81out:
 82	generic_end_io_acct(q, REQ_OP_WRITE, &pblk->disk->part0, start_time);
 83	pblk_write_should_kick(pblk);
 84
 85	if (ret == NVM_IO_DONE)
 86		bio_endio(bio);
 87}
 88
 89/*
 90 * On GC the incoming lbas are not necessarily sequential. Also, some of the
 91 * lbas might not be valid entries, which are marked as empty by the GC thread
 92 */
 93int pblk_write_gc_to_cache(struct pblk *pblk, struct pblk_gc_rq *gc_rq)
 94{
 95	struct pblk_w_ctx w_ctx;
 96	unsigned int bpos, pos;
 97	void *data = gc_rq->data;
 98	int i, valid_entries;
 99
100	/* Update the write buffer head (mem) with the entries that we can
101	 * write. The write in itself cannot fail, so there is no need to
102	 * rollback from here on.
103	 */
104retry:
105	if (!pblk_rb_may_write_gc(&pblk->rwb, gc_rq->secs_to_gc, &bpos)) {
106		io_schedule();
107		goto retry;
108	}
109
110	w_ctx.flags = PBLK_IOTYPE_GC;
111	pblk_ppa_set_empty(&w_ctx.ppa);
112
113	for (i = 0, valid_entries = 0; i < gc_rq->nr_secs; i++) {
114		if (gc_rq->lba_list[i] == ADDR_EMPTY)
115			continue;
116
117		w_ctx.lba = gc_rq->lba_list[i];
118
119		pos = pblk_rb_wrap_pos(&pblk->rwb, bpos + valid_entries);
120		pblk_rb_write_entry_gc(&pblk->rwb, data, w_ctx, gc_rq->line,
121						gc_rq->paddr_list[i], pos);
122
123		data += PBLK_EXPOSED_PAGE_SIZE;
124		valid_entries++;
125	}
126
127	WARN_ONCE(gc_rq->secs_to_gc != valid_entries,
128					"pblk: inconsistent GC write\n");
129
130	atomic64_add(valid_entries, &pblk->gc_wa);
131
132#ifdef CONFIG_NVM_PBLK_DEBUG
133	atomic_long_add(valid_entries, &pblk->inflight_writes);
134	atomic_long_add(valid_entries, &pblk->recov_gc_writes);
135#endif
136
137	pblk_write_should_kick(pblk);
138	return NVM_IO_OK;
139}