// SPDX-License-Identifier: GPL-2.0

  /*
   * 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"

  #include "pblk-trace.h"

  static unsigned int write_buffer_size;

  
  module_param(write_buffer_size, uint, 0644);
  MODULE_PARM_DESC(write_buffer_size, "number of entries in a write buffer");

  struct pblk_global_caches {
  	struct kmem_cache	*ws;
  	struct kmem_cache	*rec;
  	struct kmem_cache	*g_rq;
  	struct kmem_cache	*w_rq;
  
  	struct kref		kref;
  
  	struct mutex		mutex; /* Ensures consistency between
  					* caches and kref
  					*/
  };
  
  static struct pblk_global_caches pblk_caches = {
  	.mutex = __MUTEX_INITIALIZER(pblk_caches.mutex),
  	.kref = KREF_INIT(0),
  };

  struct bio_set pblk_bio_set;

  static blk_qc_t pblk_submit_bio(struct bio *bio)

  {

  	struct pblk *pblk = bio->bi_disk->queue->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;
  		}
  	}

  	/* 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(&bio);

  		pblk_submit_read(pblk, bio);

  	} else {
  		/* 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(&bio);

  		pblk_write_to_cache(pblk, bio, PBLK_IOTYPE_USER);

  	}
  
  	return BLK_QC_T_NONE;
  }

  static const struct block_device_operations pblk_bops = {
  	.owner		= THIS_MODULE,
  	.submit_bio	= pblk_submit_bio,
  };

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

  	if (pblk->addrf_len < 32)

  		entry_size = 4;

  	return entry_size * pblk->capacity;

  }

  #ifdef CONFIG_NVM_PBLK_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_recover(struct pblk *pblk, bool factory_init)
  {
  	struct pblk_line *line = NULL;
  
  	if (factory_init) {

  		guid_gen(&pblk->instance_uuid);

  	} else {
  		line = pblk_recov_l2p(pblk);
  		if (IS_ERR(line)) {

  			pblk_err(pblk, "could not recover l2p table
  ");

  			return -EFAULT;
  		}
  	}

  #ifdef CONFIG_NVM_PBLK_DEBUG

  	pblk_info(pblk, "init: L2P CRC: %x
  ", pblk_l2p_crc(pblk));

  #endif
  
  	/* Free full lines directly as GC has not been started yet */
  	pblk_gc_free_full_lines(pblk);
  
  	if (!line) {
  		/* Configure next line for user data */
  		line = pblk_line_get_first_data(pblk);

  		if (!line)

  			return -EFAULT;

  	}
  
  	return 0;
  }
  
  static int pblk_l2p_init(struct pblk *pblk, bool factory_init)

  {
  	sector_t i;
  	struct ppa_addr ppa;

  	size_t map_size;

  	int ret = 0;

  	map_size = pblk_trans_map_size(pblk);

  	pblk->trans_map = __vmalloc(map_size, GFP_KERNEL | __GFP_NOWARN |
  				    __GFP_RETRY_MAYFAIL | __GFP_HIGHMEM);

  	if (!pblk->trans_map) {
  		pblk_err(pblk, "failed to allocate L2P (need %zu of memory)
  ",
  				map_size);

  		return -ENOMEM;

  	}

  
  	pblk_ppa_set_empty(&ppa);

  	for (i = 0; i < pblk->capacity; i++)

  		pblk_trans_map_set(pblk, i, ppa);

  	ret = pblk_l2p_recover(pblk, factory_init);
  	if (ret)
  		vfree(pblk->trans_map);
  
  	return ret;

  }
  
  static void pblk_rwb_free(struct pblk *pblk)
  {
  	if (pblk_rb_tear_down_check(&pblk->rwb))

  		pblk_err(pblk, "write buffer error on tear down
  ");

  	pblk_rb_free(&pblk->rwb);

  }
  
  static int pblk_rwb_init(struct pblk *pblk)
  {
  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;

  	unsigned long buffer_size;

  	int pgs_in_buffer, threshold;

  	threshold = geo->mw_cunits * geo->all_luns;

  	pgs_in_buffer = (max(geo->mw_cunits, geo->ws_opt) + geo->ws_opt)
  								* geo->all_luns;

  
  	if (write_buffer_size && (write_buffer_size > pgs_in_buffer))

  		buffer_size = write_buffer_size;
  	else

  		buffer_size = pgs_in_buffer;

  	return pblk_rb_init(&pblk->rwb, buffer_size, threshold, geo->csecs);

  }

  static int pblk_set_addrf_12(struct pblk *pblk, struct nvm_geo *geo,
  			     struct nvm_addrf_12 *dst)

  {

  	struct nvm_addrf_12 *src = (struct nvm_addrf_12 *)&geo->addrf;
  	int power_len;

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

  	power_len = get_count_order(geo->num_ch);
  	if (1 << power_len != geo->num_ch) {

  		pblk_err(pblk, "supports only power-of-two channel config.
  ");

  		return -EINVAL;
  	}

  	dst->ch_len = power_len;

  	power_len = get_count_order(geo->num_lun);
  	if (1 << power_len != geo->num_lun) {

  		pblk_err(pblk, "supports only power-of-two LUN config.
  ");

  		return -EINVAL;
  	}

  	dst->lun_len = power_len;
  
  	dst->blk_len = src->blk_len;
  	dst->pg_len = src->pg_len;
  	dst->pln_len = src->pln_len;

  	dst->sec_len = src->sec_len;

  	dst->sec_offset = 0;
  	dst->pln_offset = dst->sec_len;

  	dst->ch_offset = dst->pln_offset + dst->pln_len;
  	dst->lun_offset = dst->ch_offset + dst->ch_len;
  	dst->pg_offset = dst->lun_offset + dst->lun_len;
  	dst->blk_offset = dst->pg_offset + dst->pg_len;

  	dst->sec_mask = ((1ULL << dst->sec_len) - 1) << dst->sec_offset;

  	dst->pln_mask = ((1ULL << dst->pln_len) - 1) << dst->pln_offset;
  	dst->ch_mask = ((1ULL << dst->ch_len) - 1) << dst->ch_offset;
  	dst->lun_mask = ((1ULL << dst->lun_len) - 1) << dst->lun_offset;
  	dst->pg_mask = ((1ULL << dst->pg_len) - 1) << dst->pg_offset;
  	dst->blk_mask = ((1ULL << dst->blk_len) - 1) << dst->blk_offset;
  
  	return dst->blk_offset + src->blk_len;
  }

  static int pblk_set_addrf_20(struct nvm_geo *geo, struct nvm_addrf *adst,
  			     struct pblk_addrf *udst)
  {
  	struct nvm_addrf *src = &geo->addrf;
  
  	adst->ch_len = get_count_order(geo->num_ch);
  	adst->lun_len = get_count_order(geo->num_lun);
  	adst->chk_len = src->chk_len;
  	adst->sec_len = src->sec_len;
  
  	adst->sec_offset = 0;
  	adst->ch_offset = adst->sec_len;
  	adst->lun_offset = adst->ch_offset + adst->ch_len;
  	adst->chk_offset = adst->lun_offset + adst->lun_len;
  
  	adst->sec_mask = ((1ULL << adst->sec_len) - 1) << adst->sec_offset;
  	adst->chk_mask = ((1ULL << adst->chk_len) - 1) << adst->chk_offset;
  	adst->lun_mask = ((1ULL << adst->lun_len) - 1) << adst->lun_offset;
  	adst->ch_mask = ((1ULL << adst->ch_len) - 1) << adst->ch_offset;
  
  	udst->sec_stripe = geo->ws_opt;
  	udst->ch_stripe = geo->num_ch;
  	udst->lun_stripe = geo->num_lun;
  
  	udst->sec_lun_stripe = udst->sec_stripe * udst->ch_stripe;
  	udst->sec_ws_stripe = udst->sec_lun_stripe * udst->lun_stripe;
  
  	return adst->chk_offset + adst->chk_len;
  }

  static int pblk_set_addrf(struct pblk *pblk)

  {
  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;
  	int mod;

  	switch (geo->version) {
  	case NVM_OCSSD_SPEC_12:
  		div_u64_rem(geo->clba, pblk->min_write_pgs, &mod);
  		if (mod) {

  			pblk_err(pblk, "bad configuration of sectors/pages
  ");

  			return -EINVAL;
  		}

  		pblk->addrf_len = pblk_set_addrf_12(pblk, geo,
  							(void *)&pblk->addrf);

  		break;
  	case NVM_OCSSD_SPEC_20:
  		pblk->addrf_len = pblk_set_addrf_20(geo, (void *)&pblk->addrf,

  							&pblk->uaddrf);

  		break;
  	default:

  		pblk_err(pblk, "OCSSD revision not supported (%d)
  ",

  								geo->version);

  		return -EINVAL;
  	}

  	return 0;
  }

  static int pblk_create_global_caches(void)

  {

  
  	pblk_caches.ws = kmem_cache_create("pblk_blk_ws",

  				sizeof(struct pblk_line_ws), 0, 0, NULL);

  	if (!pblk_caches.ws)

  		return -ENOMEM;

  	pblk_caches.rec = kmem_cache_create("pblk_rec",

  				sizeof(struct pblk_rec_ctx), 0, 0, NULL);

  	if (!pblk_caches.rec)
  		goto fail_destroy_ws;

  	pblk_caches.g_rq = kmem_cache_create("pblk_g_rq", pblk_g_rq_size,

  				0, 0, NULL);

  	if (!pblk_caches.g_rq)
  		goto fail_destroy_rec;

  	pblk_caches.w_rq = kmem_cache_create("pblk_w_rq", pblk_w_rq_size,

  				0, 0, NULL);

  	if (!pblk_caches.w_rq)
  		goto fail_destroy_g_rq;

  
  	return 0;

  
  fail_destroy_g_rq:
  	kmem_cache_destroy(pblk_caches.g_rq);
  fail_destroy_rec:
  	kmem_cache_destroy(pblk_caches.rec);
  fail_destroy_ws:
  	kmem_cache_destroy(pblk_caches.ws);
  
  	return -ENOMEM;
  }
  
  static int pblk_get_global_caches(void)
  {

  	int ret = 0;

  
  	mutex_lock(&pblk_caches.mutex);

  	if (kref_get_unless_zero(&pblk_caches.kref))
  		goto out;

  
  	ret = pblk_create_global_caches();

  	if (!ret)

  		kref_init(&pblk_caches.kref);

  out:

  	mutex_unlock(&pblk_caches.mutex);

  	return ret;
  }
  
  static void pblk_destroy_global_caches(struct kref *ref)
  {
  	struct pblk_global_caches *c;
  
  	c = container_of(ref, struct pblk_global_caches, kref);
  
  	kmem_cache_destroy(c->ws);
  	kmem_cache_destroy(c->rec);
  	kmem_cache_destroy(c->g_rq);
  	kmem_cache_destroy(c->w_rq);

  }

  static void pblk_put_global_caches(void)

  {

  	mutex_lock(&pblk_caches.mutex);
  	kref_put(&pblk_caches.kref, pblk_destroy_global_caches);
  	mutex_unlock(&pblk_caches.mutex);

  }

  static int pblk_core_init(struct pblk *pblk)
  {
  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;

  	int ret, max_write_ppas;

  
  	atomic64_set(&pblk->user_wa, 0);
  	atomic64_set(&pblk->pad_wa, 0);
  	atomic64_set(&pblk->gc_wa, 0);
  	pblk->user_rst_wa = 0;
  	pblk->pad_rst_wa = 0;
  	pblk->gc_rst_wa = 0;
  
  	atomic64_set(&pblk->nr_flush, 0);
  	pblk->nr_flush_rst = 0;

  	pblk->min_write_pgs = geo->ws_opt;

  	pblk->min_write_pgs_data = pblk->min_write_pgs;

  	max_write_ppas = pblk->min_write_pgs * geo->all_luns;
  	pblk->max_write_pgs = min_t(int, max_write_ppas, NVM_MAX_VLBA);

  	pblk->max_write_pgs = min_t(int, pblk->max_write_pgs,
  		queue_max_hw_sectors(dev->q) / (geo->csecs >> SECTOR_SHIFT));

  	pblk_set_sec_per_write(pblk, pblk->min_write_pgs);

  	pblk->oob_meta_size = geo->sos;

  	if (!pblk_is_oob_meta_supported(pblk)) {
  		/* For drives which does not have OOB metadata feature
  		 * in order to support recovery feature we need to use
  		 * so called packed metadata. Packed metada will store
  		 * the same information as OOB metadata (l2p table mapping,
  		 * but in the form of the single page at the end of
  		 * every write request.
  		 */
  		if (pblk->min_write_pgs
  			* sizeof(struct pblk_sec_meta) > PAGE_SIZE) {
  			/* We want to keep all the packed metadata on single
  			 * page per write requests. So we need to ensure that
  			 * it will fit.
  			 *
  			 * This is more like sanity check, since there is
  			 * no device with such a big minimal write size
  			 * (above 1 metabytes).
  			 */
  			pblk_err(pblk, "Not supported min write size
  ");
  			return -EINVAL;
  		}
  		/* For packed meta approach we do some simplification.
  		 * On read path we always issue requests which size
  		 * equal to max_write_pgs, with all pages filled with
  		 * user payload except of last one page which will be
  		 * filled with packed metadata.
  		 */
  		pblk->max_write_pgs = pblk->min_write_pgs;
  		pblk->min_write_pgs_data = pblk->min_write_pgs - 1;

  	}

  	pblk->pad_dist = kcalloc(pblk->min_write_pgs - 1, sizeof(atomic64_t),

  								GFP_KERNEL);
  	if (!pblk->pad_dist)

  		return -ENOMEM;

  	if (pblk_get_global_caches())

  		goto fail_free_pad_dist;

  	/* Internal bios can be at most the sectors signaled by the device. */

  	ret = mempool_init_page_pool(&pblk->page_bio_pool, NVM_MAX_VLBA, 0);
  	if (ret)

  		goto free_global_caches;

  	ret = mempool_init_slab_pool(&pblk->gen_ws_pool, PBLK_GEN_WS_POOL_SIZE,

  				     pblk_caches.ws);

  	if (ret)

  		goto free_page_bio_pool;

  	ret = mempool_init_slab_pool(&pblk->rec_pool, geo->all_luns,

  				     pblk_caches.rec);

  	if (ret)

  		goto free_gen_ws_pool;

  	ret = mempool_init_slab_pool(&pblk->r_rq_pool, geo->all_luns,

  				     pblk_caches.g_rq);

  	if (ret)

  		goto free_rec_pool;

  	ret = mempool_init_slab_pool(&pblk->e_rq_pool, geo->all_luns,

  				     pblk_caches.g_rq);

  	if (ret)

  		goto free_r_rq_pool;

  	ret = mempool_init_slab_pool(&pblk->w_rq_pool, geo->all_luns,

  				     pblk_caches.w_rq);

  	if (ret)

  		goto free_e_rq_pool;

  	pblk->close_wq = alloc_workqueue("pblk-close-wq",
  			WQ_MEM_RECLAIM | WQ_UNBOUND, PBLK_NR_CLOSE_JOBS);
  	if (!pblk->close_wq)

  		goto free_w_rq_pool;

  	pblk->bb_wq = alloc_workqueue("pblk-bb-wq",
  			WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
  	if (!pblk->bb_wq)
  		goto free_close_wq;

  	pblk->r_end_wq = alloc_workqueue("pblk-read-end-wq",
  			WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
  	if (!pblk->r_end_wq)

  		goto free_bb_wq;

  	if (pblk_set_addrf(pblk))

  		goto free_r_end_wq;

  	INIT_LIST_HEAD(&pblk->compl_list);

  	INIT_LIST_HEAD(&pblk->resubmit_list);

  	return 0;

  free_r_end_wq:
  	destroy_workqueue(pblk->r_end_wq);

  free_bb_wq:
  	destroy_workqueue(pblk->bb_wq);
  free_close_wq:
  	destroy_workqueue(pblk->close_wq);

  free_w_rq_pool:

  	mempool_exit(&pblk->w_rq_pool);

  free_e_rq_pool:

  	mempool_exit(&pblk->e_rq_pool);

  free_r_rq_pool:

  	mempool_exit(&pblk->r_rq_pool);

  free_rec_pool:

  	mempool_exit(&pblk->rec_pool);

  free_gen_ws_pool:

  	mempool_exit(&pblk->gen_ws_pool);

  free_page_bio_pool:

  	mempool_exit(&pblk->page_bio_pool);

  free_global_caches:

  	pblk_put_global_caches();

  fail_free_pad_dist:
  	kfree(pblk->pad_dist);

  	return -ENOMEM;
  }
  
  static void pblk_core_free(struct pblk *pblk)
  {

  	if (pblk->close_wq)
  		destroy_workqueue(pblk->close_wq);

  	if (pblk->r_end_wq)
  		destroy_workqueue(pblk->r_end_wq);

  	if (pblk->bb_wq)
  		destroy_workqueue(pblk->bb_wq);

  	mempool_exit(&pblk->page_bio_pool);
  	mempool_exit(&pblk->gen_ws_pool);
  	mempool_exit(&pblk->rec_pool);
  	mempool_exit(&pblk->r_rq_pool);
  	mempool_exit(&pblk->e_rq_pool);
  	mempool_exit(&pblk->w_rq_pool);

  	pblk_put_global_caches();

  	kfree(pblk->pad_dist);

  }

  static void pblk_line_mg_free(struct pblk *pblk)
  {
  	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
  	int i;
  
  	kfree(l_mg->bb_template);
  	kfree(l_mg->bb_aux);
  	kfree(l_mg->vsc_list);
  
  	for (i = 0; i < PBLK_DATA_LINES; i++) {
  		kfree(l_mg->sline_meta[i]);

  		kvfree(l_mg->eline_meta[i]->buf);

  		kfree(l_mg->eline_meta[i]);
  	}

  
  	mempool_destroy(l_mg->bitmap_pool);
  	kmem_cache_destroy(l_mg->bitmap_cache);

  }

  static void pblk_line_meta_free(struct pblk_line_mgmt *l_mg,
  				struct pblk_line *line)

  {

  	struct pblk_w_err_gc *w_err_gc = line->w_err_gc;

  	kfree(line->blk_bitmap);
  	kfree(line->erase_bitmap);

  	kfree(line->chks);

  	kvfree(w_err_gc->lba_list);

  	kfree(w_err_gc);

  }

  static void pblk_lines_free(struct pblk *pblk)
  {
  	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
  	struct pblk_line *line;
  	int i;

  	for (i = 0; i < l_mg->nr_lines; i++) {
  		line = &pblk->lines[i];

  		pblk_line_free(line);

  		pblk_line_meta_free(l_mg, line);

  	}

  
  	pblk_line_mg_free(pblk);
  
  	kfree(pblk->luns);
  	kfree(pblk->lines);

  }

  static int pblk_luns_init(struct pblk *pblk)

  {
  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;
  	struct pblk_lun *rlun;

  	int i;

  
  	/* TODO: Implement unbalanced LUN support */

  	if (geo->num_lun < 0) {

  		pblk_err(pblk, "unbalanced LUN config.
  ");

  		return -EINVAL;
  	}

  	pblk->luns = kcalloc(geo->all_luns, sizeof(struct pblk_lun),
  								GFP_KERNEL);

  	if (!pblk->luns)
  		return -ENOMEM;

  	for (i = 0; i < geo->all_luns; i++) {

  		/* Stripe across channels */

  		int ch = i % geo->num_ch;
  		int lun_raw = i / geo->num_ch;
  		int lunid = lun_raw + ch * geo->num_lun;

  
  		rlun = &pblk->luns[i];

  		rlun->bppa = dev->luns[lunid];

  
  		sema_init(&rlun->wr_sem, 1);

  	}
  
  	return 0;
  }

  /* See comment over struct line_emeta definition */

  static unsigned int calc_emeta_len(struct pblk *pblk)

  {

  	struct pblk_line_meta *lm = &pblk->lm;
  	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;
  
  	/* Round to sector size so that lba_list starts on its own sector */
  	lm->emeta_sec[1] = DIV_ROUND_UP(

  			sizeof(struct line_emeta) + lm->blk_bitmap_len +

  			sizeof(struct wa_counters), geo->csecs);
  	lm->emeta_len[1] = lm->emeta_sec[1] * geo->csecs;

  
  	/* Round to sector size so that vsc_list starts on its own sector */
  	lm->dsec_per_line = lm->sec_per_line - lm->emeta_sec[0];
  	lm->emeta_sec[2] = DIV_ROUND_UP(lm->dsec_per_line * sizeof(u64),

  			geo->csecs);
  	lm->emeta_len[2] = lm->emeta_sec[2] * geo->csecs;

  
  	lm->emeta_sec[3] = DIV_ROUND_UP(l_mg->nr_lines * sizeof(u32),

  			geo->csecs);
  	lm->emeta_len[3] = lm->emeta_sec[3] * geo->csecs;

  
  	lm->vsc_list_len = l_mg->nr_lines * sizeof(u32);
  
  	return (lm->emeta_len[1] + lm->emeta_len[2] + lm->emeta_len[3]);

  }

  static int pblk_set_provision(struct pblk *pblk, int nr_free_chks)

  {
  	struct nvm_tgt_dev *dev = pblk->dev;

  	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
  	struct pblk_line_meta *lm = &pblk->lm;

  	struct nvm_geo *geo = &dev->geo;
  	sector_t provisioned;

  	int sec_meta, blk_meta, clba;

  	int minimum;

  	if (geo->op == NVM_TARGET_DEFAULT_OP)
  		pblk->op = PBLK_DEFAULT_OP;
  	else
  		pblk->op = geo->op;

  	minimum = pblk_get_min_chks(pblk);
  	provisioned = nr_free_chks;

  	provisioned *= (100 - pblk->op);

  	sector_div(provisioned, 100);

  	if ((nr_free_chks - provisioned) < minimum) {
  		if (geo->op != NVM_TARGET_DEFAULT_OP) {
  			pblk_err(pblk, "OP too small to create a sane instance
  ");
  			return -EINTR;
  		}
  
  		/* If the user did not specify an OP value, and PBLK_DEFAULT_OP
  		 * is not enough, calculate and set sane value
  		 */
  
  		provisioned = nr_free_chks - minimum;
  		pblk->op =  (100 * minimum) / nr_free_chks;
  		pblk_info(pblk, "Default OP insufficient, adjusting OP to %d
  ",
  				pblk->op);
  	}
  
  	pblk->op_blks = nr_free_chks - provisioned;

  	/* Internally pblk manages all free blocks, but all calculations based
  	 * on user capacity consider only provisioned blocks
  	 */

  	pblk->rl.total_blocks = nr_free_chks;

  
  	/* Consider sectors used for metadata */
  	sec_meta = (lm->smeta_sec + lm->emeta_sec[0]) * l_mg->nr_free_lines;

  	blk_meta = DIV_ROUND_UP(sec_meta, geo->clba);

  	clba = (geo->clba / pblk->min_write_pgs) * pblk->min_write_pgs_data;
  	pblk->capacity = (provisioned - blk_meta) * clba;

  	atomic_set(&pblk->rl.free_blocks, nr_free_chks);
  	atomic_set(&pblk->rl.free_user_blocks, nr_free_chks);
  
  	return 0;

  }

  static int pblk_setup_line_meta_chk(struct pblk *pblk, struct pblk_line *line,

  				   struct nvm_chk_meta *meta)
  {
  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;
  	struct pblk_line_meta *lm = &pblk->lm;
  	int i, nr_bad_chks = 0;
  
  	for (i = 0; i < lm->blk_per_line; i++) {
  		struct pblk_lun *rlun = &pblk->luns[i];
  		struct nvm_chk_meta *chunk;
  		struct nvm_chk_meta *chunk_meta;
  		struct ppa_addr ppa;
  		int pos;
  
  		ppa = rlun->bppa;
  		pos = pblk_ppa_to_pos(geo, ppa);
  		chunk = &line->chks[pos];
  
  		ppa.m.chk = line->id;
  		chunk_meta = pblk_chunk_get_off(pblk, meta, ppa);
  
  		chunk->state = chunk_meta->state;
  		chunk->type = chunk_meta->type;
  		chunk->wi = chunk_meta->wi;
  		chunk->slba = chunk_meta->slba;
  		chunk->cnlb = chunk_meta->cnlb;
  		chunk->wp = chunk_meta->wp;

  		trace_pblk_chunk_state(pblk_disk_name(pblk), &ppa,
  					chunk->state);

  		if (chunk->type & NVM_CHK_TP_SZ_SPEC) {
  			WARN_ONCE(1, "pblk: custom-sized chunks unsupported
  ");
  			continue;
  		}

  		if (!(chunk->state & NVM_CHK_ST_OFFLINE))
  			continue;

  		set_bit(pos, line->blk_bitmap);
  		nr_bad_chks++;
  	}
  
  	return nr_bad_chks;
  }
  
  static long pblk_setup_line_meta(struct pblk *pblk, struct pblk_line *line,
  				 void *chunk_meta, int line_id)
  {

  	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
  	struct pblk_line_meta *lm = &pblk->lm;
  	long nr_bad_chks, chk_in_line;
  
  	line->pblk = pblk;
  	line->id = line_id;
  	line->type = PBLK_LINETYPE_FREE;
  	line->state = PBLK_LINESTATE_NEW;
  	line->gc_group = PBLK_LINEGC_NONE;
  	line->vsc = &l_mg->vsc_list[line_id];
  	spin_lock_init(&line->lock);

  	nr_bad_chks = pblk_setup_line_meta_chk(pblk, line, chunk_meta);

  
  	chk_in_line = lm->blk_per_line - nr_bad_chks;
  	if (nr_bad_chks < 0 || nr_bad_chks > lm->blk_per_line ||
  					chk_in_line < lm->min_blk_line) {
  		line->state = PBLK_LINESTATE_BAD;
  		list_add_tail(&line->list, &l_mg->bad_list);
  		return 0;
  	}
  
  	atomic_set(&line->blk_in_line, chk_in_line);
  	list_add_tail(&line->list, &l_mg->free_list);
  	l_mg->nr_free_lines++;
  
  	return chk_in_line;
  }
  
  static int pblk_alloc_line_meta(struct pblk *pblk, struct pblk_line *line)

  {
  	struct pblk_line_meta *lm = &pblk->lm;
  
  	line->blk_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);
  	if (!line->blk_bitmap)
  		return -ENOMEM;
  
  	line->erase_bitmap = kzalloc(lm->blk_bitmap_len, GFP_KERNEL);

  	if (!line->erase_bitmap)
  		goto free_blk_bitmap;

  	line->chks = kmalloc_array(lm->blk_per_line,
  				   sizeof(struct nvm_chk_meta), GFP_KERNEL);

  	if (!line->chks)
  		goto free_erase_bitmap;
  
  	line->w_err_gc = kzalloc(sizeof(struct pblk_w_err_gc), GFP_KERNEL);
  	if (!line->w_err_gc)
  		goto free_chks;

  
  	return 0;

  
  free_chks:
  	kfree(line->chks);
  free_erase_bitmap:
  	kfree(line->erase_bitmap);
  free_blk_bitmap:
  	kfree(line->blk_bitmap);
  	return -ENOMEM;

  }
  
  static int pblk_line_mg_init(struct pblk *pblk)

  {

  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;

  	struct pblk_line_mgmt *l_mg = &pblk->l_mg;
  	struct pblk_line_meta *lm = &pblk->lm;

  	int i, bb_distance;

  	l_mg->nr_lines = geo->num_chk;

  	l_mg->log_line = l_mg->data_line = NULL;
  	l_mg->l_seq_nr = l_mg->d_seq_nr = 0;
  	l_mg->nr_free_lines = 0;
  	bitmap_zero(&l_mg->meta_bitmap, PBLK_DATA_LINES);
  
  	INIT_LIST_HEAD(&l_mg->free_list);
  	INIT_LIST_HEAD(&l_mg->corrupt_list);
  	INIT_LIST_HEAD(&l_mg->bad_list);
  	INIT_LIST_HEAD(&l_mg->gc_full_list);
  	INIT_LIST_HEAD(&l_mg->gc_high_list);
  	INIT_LIST_HEAD(&l_mg->gc_mid_list);
  	INIT_LIST_HEAD(&l_mg->gc_low_list);
  	INIT_LIST_HEAD(&l_mg->gc_empty_list);

  	INIT_LIST_HEAD(&l_mg->gc_werr_list);

  
  	INIT_LIST_HEAD(&l_mg->emeta_list);

  	l_mg->gc_lists[0] = &l_mg->gc_werr_list;
  	l_mg->gc_lists[1] = &l_mg->gc_high_list;
  	l_mg->gc_lists[2] = &l_mg->gc_mid_list;
  	l_mg->gc_lists[3] = &l_mg->gc_low_list;

  
  	spin_lock_init(&l_mg->free_lock);
  	spin_lock_init(&l_mg->close_lock);
  	spin_lock_init(&l_mg->gc_lock);
  
  	l_mg->vsc_list = kcalloc(l_mg->nr_lines, sizeof(__le32), GFP_KERNEL);
  	if (!l_mg->vsc_list)
  		goto fail;
  
  	l_mg->bb_template = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
  	if (!l_mg->bb_template)
  		goto fail_free_vsc_list;
  
  	l_mg->bb_aux = kzalloc(lm->sec_bitmap_len, GFP_KERNEL);
  	if (!l_mg->bb_aux)
  		goto fail_free_bb_template;

  
  	/* smeta is always small enough to fit on a kmalloc memory allocation,
  	 * emeta depends on the number of LUNs allocated to the pblk instance
  	 */

  	for (i = 0; i < PBLK_DATA_LINES; i++) {
  		l_mg->sline_meta[i] = kmalloc(lm->smeta_len, GFP_KERNEL);
  		if (!l_mg->sline_meta[i])
  			goto fail_free_smeta;
  	}

  	l_mg->bitmap_cache = kmem_cache_create("pblk_lm_bitmap",
  			lm->sec_bitmap_len, 0, 0, NULL);
  	if (!l_mg->bitmap_cache)
  		goto fail_free_smeta;
  
  	/* the bitmap pool is used for both valid and map bitmaps */
  	l_mg->bitmap_pool = mempool_create_slab_pool(PBLK_DATA_LINES * 2,
  				l_mg->bitmap_cache);
  	if (!l_mg->bitmap_pool)
  		goto fail_destroy_bitmap_cache;

  	/* emeta allocates three different buffers for managing metadata with
  	 * in-memory and in-media layouts
  	 */
  	for (i = 0; i < PBLK_DATA_LINES; i++) {
  		struct pblk_emeta *emeta;
  
  		emeta = kmalloc(sizeof(struct pblk_emeta), GFP_KERNEL);
  		if (!emeta)
  			goto fail_free_emeta;

  		emeta->buf = kvmalloc(lm->emeta_len[0], GFP_KERNEL);
  		if (!emeta->buf) {
  			kfree(emeta);
  			goto fail_free_emeta;

  		}

  
  		emeta->nr_entries = lm->emeta_sec[0];
  		l_mg->eline_meta[i] = emeta;

  	}

  	for (i = 0; i < l_mg->nr_lines; i++)
  		l_mg->vsc_list[i] = cpu_to_le32(EMPTY_ENTRY);

  	bb_distance = (geo->all_luns) * geo->ws_opt;
  	for (i = 0; i < lm->sec_per_line; i += bb_distance)
  		bitmap_set(l_mg->bb_template, i, geo->ws_opt);

  	return 0;
  
  fail_free_emeta:
  	while (--i >= 0) {

  		kvfree(l_mg->eline_meta[i]->buf);

  		kfree(l_mg->eline_meta[i]);

  	}

  
  	mempool_destroy(l_mg->bitmap_pool);
  fail_destroy_bitmap_cache:
  	kmem_cache_destroy(l_mg->bitmap_cache);

  fail_free_smeta:
  	for (i = 0; i < PBLK_DATA_LINES; i++)

  		kfree(l_mg->sline_meta[i]);

  	kfree(l_mg->bb_aux);
  fail_free_bb_template:
  	kfree(l_mg->bb_template);
  fail_free_vsc_list:
  	kfree(l_mg->vsc_list);
  fail:

  	return -ENOMEM;
  }

  static int pblk_line_meta_init(struct pblk *pblk)

  {
  	struct nvm_tgt_dev *dev = pblk->dev;
  	struct nvm_geo *geo = &dev->geo;

  	struct pblk_line_meta *lm = &pblk->lm;

  	unsigned int smeta_len, emeta_len;

  	int i;

  	lm->sec_per_line = geo->clba * geo->all_luns;

  	lm->blk_per_line = geo->all_luns;
  	lm->blk_bitmap_len = BITS_TO_LONGS(geo->all_luns) * sizeof(long);

  	lm->sec_bitmap_len = BITS_TO_LONGS(lm->sec_per_line) * sizeof(long);

  	lm->lun_bitmap_len = BITS_TO_LONGS(geo->all_luns) * sizeof(long);

  	lm->mid_thrs = lm->sec_per_line / 2;
  	lm->high_thrs = lm->sec_per_line / 4;

  	lm->meta_distance = (geo->all_luns / 2) * pblk->min_write_pgs;

  
  	/* Calculate necessary pages for smeta. See comment over struct
  	 * line_smeta definition
  	 */

  	i = 1;
  add_smeta_page:

  	lm->smeta_sec = i * geo->ws_opt;
  	lm->smeta_len = lm->smeta_sec * geo->csecs;

  	smeta_len = sizeof(struct line_smeta) + lm->lun_bitmap_len;

  	if (smeta_len > lm->smeta_len) {
  		i++;
  		goto add_smeta_page;
  	}
  
  	/* Calculate necessary pages for emeta. See comment over struct
  	 * line_emeta definition
  	 */
  	i = 1;
  add_emeta_page:

  	lm->emeta_sec[0] = i * geo->ws_opt;
  	lm->emeta_len[0] = lm->emeta_sec[0] * geo->csecs;

  	emeta_len = calc_emeta_len(pblk);
  	if (emeta_len > lm->emeta_len[0]) {

  		i++;
  		goto add_emeta_page;
  	}

  	lm->emeta_bb = geo->all_luns > i ? geo->all_luns - i : 0;

  
  	lm->min_blk_line = 1;

  	if (geo->all_luns > 1)

  		lm->min_blk_line += DIV_ROUND_UP(lm->smeta_sec +

  					lm->emeta_sec[0], geo->clba);

  	if (lm->min_blk_line > lm->blk_per_line) {

  		pblk_err(pblk, "config. not supported. Min. LUN in line:%d
  ",

  							lm->blk_per_line);

  		return -EINVAL;

  	}

  	return 0;
  }
  
  static int pblk_lines_init(struct pblk *pblk)
  {
  	struct pblk_line_mgmt *l_mg = &pblk->l_mg;

  	struct pblk_line *line;

  	void *chunk_meta;

  	int nr_free_chks = 0;

  	int i, ret;
  
  	ret = pblk_line_meta_init(pblk);

  	if (ret)

  		return ret;

  	ret = pblk_line_mg_init(pblk);
  	if (ret)
  		return ret;
  
  	ret = pblk_luns_init(pblk);
  	if (ret)

  		goto fail_free_meta;

  	chunk_meta = pblk_get_chunk_meta(pblk);

  	if (IS_ERR(chunk_meta)) {
  		ret = PTR_ERR(chunk_meta);

  		goto fail_free_luns;

  	}

  	pblk->lines = kcalloc(l_mg->nr_lines, sizeof(struct pblk_line),
  								GFP_KERNEL);

  	if (!pblk->lines) {
  		ret = -ENOMEM;

  		goto fail_free_chunk_meta;

  	}

  	for (i = 0; i < l_mg->nr_lines; i++) {
  		line = &pblk->lines[i];

  		ret = pblk_alloc_line_meta(pblk, line);

  		if (ret)

  			goto fail_free_lines;

  		nr_free_chks += pblk_setup_line_meta(pblk, line, chunk_meta, i);

  
  		trace_pblk_line_state(pblk_disk_name(pblk), line->id,
  								line->state);

  	}

  	if (!nr_free_chks) {

  		pblk_err(pblk, "too many bad blocks prevent for sane instance
  ");

  		ret = -EINTR;
  		goto fail_free_lines;

  	}

  	ret = pblk_set_provision(pblk, nr_free_chks);
  	if (ret)
  		goto fail_free_lines;

  	vfree(chunk_meta);

  	return 0;

  fail_free_lines:

  	while (--i >= 0)

  		pblk_line_meta_free(l_mg, &pblk->lines[i]);

  	kfree(pblk->lines);

  fail_free_chunk_meta:

  	vfree(chunk_meta);

  fail_free_luns:
  	kfree(pblk->luns);

  fail_free_meta:

  	pblk_line_mg_free(pblk);

  
  	return ret;
  }
  
  static int pblk_writer_init(struct pblk *pblk)
  {

  	pblk->writer_ts = kthread_create(pblk_write_ts, pblk, "pblk-writer-t");
  	if (IS_ERR(pblk->writer_ts)) {

  		int err = PTR_ERR(pblk->writer_ts);
  
  		if (err != -EINTR)

  			pblk_err(pblk, "could not allocate writer kthread (%d)
  ",

  					err);
  		return err;

  	}

  	timer_setup(&pblk->wtimer, pblk_write_timer_fn, 0);
  	mod_timer(&pblk->wtimer, jiffies + msecs_to_jiffies(100));

  	return 0;
  }
  
  static void pblk_writer_stop(struct pblk *pblk)
  {

  	/* The pipeline must be stopped and the write buffer emptied before the
  	 * write thread is stopped
  	 */
  	WARN(pblk_rb_read_count(&pblk->rwb),
  			"Stopping not fully persisted write buffer
  ");
  
  	WARN(pblk_rb_sync_count(&pblk->rwb),
  			"Stopping not fully synced write buffer
  ");

  	del_timer_sync(&pblk->wtimer);

  	if (pblk->writer_ts)
  		kthread_stop(pblk->writer_ts);

  }
  
  static void pblk_free(struct pblk *pblk)
  {

  	pblk_lines_free(pblk);

  	pblk_l2p_free(pblk);

  	pblk_rwb_free(pblk);
  	pblk_core_free(pblk);

  
  	kfree(pblk);
  }

  static void pblk_tear_down(struct pblk *pblk, bool graceful)

  {

  	if (graceful)
  		__pblk_pipeline_flush(pblk);
  	__pblk_pipeline_stop(pblk);

  	pblk_writer_stop(pblk);
  	pblk_rb_sync_l2p(&pblk->rwb);

  	pblk_rl_free(&pblk->rl);

  	pblk_debug(pblk, "consistent tear down (graceful:%d)
  ", graceful);

  }

  static void pblk_exit(void *private, bool graceful)

  {
  	struct pblk *pblk = private;

  	pblk_gc_exit(pblk, graceful);
  	pblk_tear_down(pblk, graceful);

  #ifdef CONFIG_NVM_PBLK_DEBUG

  	pblk_info(pblk, "exit: L2P CRC: %x
  ", pblk_l2p_crc(pblk));

  #endif

  	pblk_free(pblk);

  }
  
  static sector_t pblk_capacity(void *private)
  {
  	struct pblk *pblk = private;
  
  	return pblk->capacity * NR_PHY_IN_LOG;
  }
  
  static void *pblk_init(struct nvm_tgt_dev *dev, struct gendisk *tdisk,
  		       int flags)
  {
  	struct nvm_geo *geo = &dev->geo;
  	struct request_queue *bqueue = dev->q;
  	struct request_queue *tqueue = tdisk->queue;
  	struct pblk *pblk;
  	int ret;

  	pblk = kzalloc(sizeof(struct pblk), GFP_KERNEL);
  	if (!pblk)
  		return ERR_PTR(-ENOMEM);
  
  	pblk->dev = dev;
  	pblk->disk = tdisk;
  	pblk->state = PBLK_STATE_RUNNING;

  	trace_pblk_state(pblk_disk_name(pblk), pblk->state);

  	pblk->gc.gc_enabled = 0;

  	if (!(geo->version == NVM_OCSSD_SPEC_12 ||
  					geo->version == NVM_OCSSD_SPEC_20)) {

  		pblk_err(pblk, "OCSSD version not supported (%u)
  ",

  							geo->version);

  		kfree(pblk);

  		return ERR_PTR(-EINVAL);
  	}

  	if (geo->ext) {
  		pblk_err(pblk, "extended metadata not supported
  ");
  		kfree(pblk);
  		return ERR_PTR(-EINVAL);
  	}

  	spin_lock_init(&pblk->resubmit_lock);

  	spin_lock_init(&pblk->trans_lock);
  	spin_lock_init(&pblk->lock);

  #ifdef CONFIG_NVM_PBLK_DEBUG

  	atomic_long_set(&pblk->inflight_writes, 0);
  	atomic_long_set(&pblk->padded_writes, 0);
  	atomic_long_set(&pblk->padded_wb, 0);

  	atomic_long_set(&pblk->req_writes, 0);
  	atomic_long_set(&pblk->sub_writes, 0);
  	atomic_long_set(&pblk->sync_writes, 0);

  	atomic_long_set(&pblk->inflight_reads, 0);

  	atomic_long_set(&pblk->cache_reads, 0);

  	atomic_long_set(&pblk->sync_reads, 0);
  	atomic_long_set(&pblk->recov_writes, 0);
  	atomic_long_set(&pblk->recov_writes, 0);
  	atomic_long_set(&pblk->recov_gc_writes, 0);

  	atomic_long_set(&pblk->recov_gc_reads, 0);

  #endif
  
  	atomic_long_set(&pblk->read_failed, 0);
  	atomic_long_set(&pblk->read_empty, 0);
  	atomic_long_set(&pblk->read_high_ecc, 0);
  	atomic_long_set(&pblk->read_failed_gc, 0);
  	atomic_long_set(&pblk->write_failed, 0);
  	atomic_long_set(&pblk->erase_failed, 0);

  	ret = pblk_core_init(pblk);

  	if (ret) {

  		pblk_err(pblk, "could not initialize core
  ");

  		goto fail;
  	}
  
  	ret = pblk_lines_init(pblk);
  	if (ret) {

  		pblk_err(pblk, "could not initialize lines
  ");

  		goto fail_free_core;

  	}

  	ret = pblk_rwb_init(pblk);

  	if (ret) {

  		pblk_err(pblk, "could not initialize write buffer
  ");

  		goto fail_free_lines;

  	}

  	ret = pblk_l2p_init(pblk, flags & NVM_TARGET_FACTORY);

  	if (ret) {

  		pblk_err(pblk, "could not initialize maps
  ");

  		goto fail_free_rwb;

  	}
  
  	ret = pblk_writer_init(pblk);
  	if (ret) {

  		if (ret != -EINTR)

  			pblk_err(pblk, "could not initialize write thread
  ");

  		goto fail_free_l2p;

  	}
  
  	ret = pblk_gc_init(pblk);
  	if (ret) {

  		pblk_err(pblk, "could not initialize gc
  ");

  		goto fail_stop_writer;
  	}
  
  	/* inherit the size from the underlying device */
  	blk_queue_logical_block_size(tqueue, queue_physical_block_size(bqueue));
  	blk_queue_max_hw_sectors(tqueue, queue_max_hw_sectors(bqueue));
  
  	blk_queue_write_cache(tqueue, true, false);

  	tqueue->limits.discard_granularity = geo->clba * geo->csecs;

  	tqueue->limits.discard_alignment = 0;
  	blk_queue_max_discard_sectors(tqueue, UINT_MAX >> 9);

  	blk_queue_flag_set(QUEUE_FLAG_DISCARD, tqueue);

  	pblk_info(pblk, "luns:%u, lines:%d, secs:%llu, buf entries:%u
  ",

  			geo->all_luns, pblk->l_mg.nr_lines,

  			(unsigned long long)pblk->capacity,

  			pblk->rwb.nr_entries);
  
  	wake_up_process(pblk->writer_ts);

  
  	/* Check if we need to start GC */
  	pblk_gc_should_kick(pblk);

  	return pblk;
  
  fail_stop_writer:
  	pblk_writer_stop(pblk);

  fail_free_l2p:
  	pblk_l2p_free(pblk);

  fail_free_rwb:
  	pblk_rwb_free(pblk);
  fail_free_lines:
  	pblk_lines_free(pblk);

  fail_free_core:
  	pblk_core_free(pblk);

  fail:
  	kfree(pblk);
  	return ERR_PTR(ret);
  }
  
  /* physical block device target */
  static struct nvm_tgt_type tt_pblk = {
  	.name		= "pblk",
  	.version	= {1, 0, 0},

  	.bops		= &pblk_bops,

  	.capacity	= pblk_capacity,
  
  	.init		= pblk_init,
  	.exit		= pblk_exit,
  
  	.sysfs_init	= pblk_sysfs_init,
  	.sysfs_exit	= pblk_sysfs_exit,

  	.owner		= THIS_MODULE,

  };
  
  static int __init pblk_module_init(void)
  {

  	int ret;

  	ret = bioset_init(&pblk_bio_set, BIO_POOL_SIZE, 0, 0);
  	if (ret)
  		return ret;

  	ret = nvm_register_tgt_type(&tt_pblk);
  	if (ret)

  		bioset_exit(&pblk_bio_set);

  	return ret;

  }
  
  static void pblk_module_exit(void)
  {

  	bioset_exit(&pblk_bio_set);

  	nvm_unregister_tgt_type(&tt_pblk);
  }
  
  module_init(pblk_module_init);
  module_exit(pblk_module_exit);
  MODULE_AUTHOR("Javier Gonzalez <javier@cnexlabs.com>");
  MODULE_AUTHOR("Matias Bjorling <matias@cnexlabs.com>");
  MODULE_LICENSE("GPL v2");
  MODULE_DESCRIPTION("Physical Block-Device for Open-Channel SSDs");