path: root/drivers/lightnvm/pblk-init.c

/*
 * Copyright (C) 2015 IT University of Copenhagen (rrpc.c)
 * Copyright (C) 2016 CNEX Labs
 * Initial release: Javier Gonzalez <javier@cnexlabs.com>
 *                  Matias Bjorling <matias@cnexlabs.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * Implementation of a physical block-device target for Open-channel SSDs.
 *
 * pblk-init.c - pblk's initialization.
 */

#include "pblk.h"

static struct kmem_cache *pblk_ws_cache, *pblk_rec_cache, *pblk_g_rq_cache,
				*pblk_w_rq_cache;
static DECLARE_RWSEM(pblk_lock);
struct bio_set *pblk_bio_set;

static int pblk_rw_io(struct request_queue *q, struct pblk *pblk,
			  struct bio *bio)
{
	int ret;

	/* Read requests must be <= 256kb due to NVMe's 64 bit completion bitmap
	 * constraint. Writes can be of arbitrary size.
	 */
	if (bio_data_dir(bio) == READ) {
		blk_queue_split(q, &bio);
		ret = pblk_submit_read(pblk, bio);
		if (ret == NVM_IO_DONE && bio_flagged(bio, BIO_CLONED))
			bio_put(bio);

		return ret;
	}

	/* Prevent deadlock in the case of a modest LUN configuration and large
	 * user I/Os. Unless stalled, the rate limiter leaves at least 256KB
	 * available for user I/O.
	 */
	if (pblk_get_secs(bio) > pblk_rl_max_io(&pblk->rl))
		blk_queue_split(q, &bio);

	return pblk_write_to_cache(pblk, bio, PBLK_IOTYPE_USER);
}

static blk_qc_t pblk_make_rq(struct request_queue *q, struct bio *bio)
{
	struct pblk *pblk = q->queuedata;

	if (bio_op(bio) == REQ_OP_DISCARD) {
		pblk_discard(pblk, bio);
		if (!(bio->bi_opf & REQ_PREFLUSH)) {
			bio_endio(bio);
			return BLK_QC_T_NONE;
		}
	}

	switch (pblk_rw_io(q, pblk, bio)) {
	case NVM_IO_ERR:
		bio_io_error(bio);
		break;
	case NVM_IO_DONE:
		bio_endio(bio);
		break;
	}

	return BLK_QC_T_NONE;
}

static size_t pblk_trans_map_size(struct pblk *pblk)
{
	int entry_size = 8;

	if (pblk->ppaf_bitsize < 32)
		entry_size = 4;

	return entry_size * pblk->rl.nr_secs;
}

#ifdef CONFIG_NVM_DEBUG
static u32 pblk_l2p_crc(struct pblk *pblk)
{
	size_t map_size;
	u32 crc = ~(u32)0;

	map_size = pblk_trans_map_size(pblk);
	crc = crc32_le(crc, pblk->trans_map, map_size);
	return crc;
}
#endif

static void pblk_l2p_free(struct pblk *pblk)
{
	vfree(pblk->trans_map);
}

static int pblk_l2p_init(struct pblk *pblk)
{
	sector_t i;
	struct ppa_addr ppa;
	size_t map_size;

	map_size = pblk_trans_map_size(pblk);
	pblk->trans_map = vmalloc(map_size);
	if (!pblk->trans_map)
		return -ENOMEM;

	pblk_ppa_set_empty(&ppa);

	for (i = 0; i < pblk->rl.nr_secs; i++)
		pblk_trans_map_set(pblk, i, ppa);

	return 0;
}

static void pblk_rwb_free(struct pblk *pblk)
{
	if (pblk_rb_tear_down_check(&pblk->rwb))
		pr_err("pblk: write buffer error on tear down\n");

	pblk_rb_data_free(&pblk->rwb);
	vfree(pblk_rb_entries_ref(&pblk->rwb));
}

static int pblk_rwb_init(struct pblk *pblk)
{
	struct nvm_tgt_dev *dev = pblk->dev;
	struct nvm_geo *geo = &dev->geo;
	struct pblk_rb_entry *entries;
	unsigned long nr_entries;
	unsigned int power_size, power_seg_sz;

	nr_entries = pblk_rb_calculate_size(pblk->pgs_in_buffer);

	entries = vzalloc(nr_entries * sizeof(struct pblk_rb_entry));
	if (!entries)
		return -ENOMEM;

	power_size = get_count_order(nr_entries);
	power_seg_sz = get_count_order(geo->sec_size);

	return pblk_rb_init(&pblk->rwb, entries, power_size, power_seg_sz);
}

/* Minimum pages needed within a lun */
#define ADDR_POOL_SIZE 64

static int pblk_set_ppaf(struct pblk *pblk)
{
	struct nvm_tgt_dev *dev = pblk->dev;
	struct nvm_geo *geo = &dev->geo;
	struct nvm_addr_format ppaf = geo->ppaf;
	int power_len;

	/* Re-calculate channel and lun format to adapt to configuration */
	power_len