[linux-2.6-block.git] / drivers / lightnvm / rrpc.h

/*
 * Copyright (C) 2015 IT University of Copenhagen
 * Initial release: Matias Bjorling <m@bjorling.me>
 *
 * 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 Round-robin page-based Hybrid FTL for Open-channel SSDs.
 */

#ifndef RRPC_H_
#define RRPC_H_

#include <linux/blkdev.h>
#include <linux/blk-mq.h>
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/vmalloc.h>

#include <linux/lightnvm.h>

/* Run only GC if less than 1/X blocks are free */
#define GC_LIMIT_INVERSE 10
#define GC_TIME_SECS 100

#define RRPC_SECTOR (512)
#define RRPC_EXPOSED_PAGE_SIZE (4096)

#define NR_PHY_IN_LOG (RRPC_EXPOSED_PAGE_SIZE / RRPC_SECTOR)

struct rrpc_inflight {
	struct list_head reqs;
	spinlock_t lock;
};

struct rrpc_inflight_rq {
	struct list_head list;
	sector_t l_start;
	sector_t l_end;
};

struct rrpc_rq {
	struct rrpc_inflight_rq inflight_rq;
	struct rrpc_addr *addr;
	unsigned long flags;
};

struct rrpc_block {
	struct nvm_block *parent;
	struct rrpc_lun *rlun;
	struct list_head prio;

#define MAX_INVALID_PAGES_STORAGE 8
	/* Bitmap for invalid page intries */
	unsigned long invalid_pages[MAX_INVALID_PAGES_STORAGE];
	/* points to the next writable page within a block */
	unsigned int next_page;
	/* number of pages that are invalid, wrt host page size */
	unsigned int nr_invalid_pages;

	spinlock_t lock;
	atomic_t data_cmnt_size; /* data pages committed to stable storage */
};

struct rrpc_lun {
	struct rrpc *rrpc;
	struct nvm_lun *parent;
	struct rrpc_block *cur, *gc_cur;
	struct rrpc_block *blocks;	/* Reference to block allocation */

	struct list_head prio_list;	/* Blocks that may be GC'ed */

	struct work_struct ws_gc;

	spinlock_t lock;
};

struct rrpc {
	/* instance must be kept in top to resolve rrpc in unprep */
	struct nvm_tgt_instance instance;

	struct nvm_dev *dev;
	struct gendisk *disk;

	sector_t soffset; /* logical sector offset */
	u64 poffset; /* physical page offset */
	int lun_offset;

	int nr_luns;
	struct rrpc_lun *luns;

	/* calculated values */
	unsigned long long nr_sects;
	unsigned long total_blocks;

	/* Write strategy variables. Move these into each for structure for each
	 * strategy
	 */
	atomic_t next_lun; /* Whenever a page is written, this is updated
			    * to point to the next write lun
			    */

	spinlock_t bio_lock;
	struct bio_list requeue_bios;
	struct work_struct ws_requeue;

	/* Simple translation map of logical addresses to physical addresses.
	 * The logical addresses is known by the host system, while the physical
	 * addresses are used when writing to the disk block device.
	 */
	struct rrpc_addr *trans_map;
	/* also store a reverse map for garbage collection */
	struct rrpc_rev_addr *rev_trans_map;
	spinlock_t rev_lock;

	struct rrpc_inflight inflights;

	mempool_t *addr_pool;
	mempool_t *page_pool;
	mempool_t *gcb_pool;
	mempool_t *rq_pool;

	struct timer_list gc_timer;
	struct workqueue_struct *krqd_wq;
	struct workqueue_struct *kgc_wq;
};

struct rrpc_block_gc {
	struct rrpc *rrpc;
	struct rrpc_block *rblk;
	struct work_struct ws_gc;
};

/* Logical to physical mapping */
struct rrpc_addr {
	u64 addr;
	struct rrpc_block *rblk;
};

/* Physical to logical mapping */
struct rrpc_rev_addr {
	u64 addr;
};

static inline struct rrpc_block *rrpc_get_rblk(struct rrpc_lun *rlun,
								int blk_id)
{
	struct rrpc *rrpc = rlun->rrpc;
	int lun_blk = blk_id % rrpc->dev->blks_per_lun;

	return &rlun->blocks[lun_blk];
}

static inline sector_t rrpc_get_laddr(struct bio *bio)
{
	return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
}

static inline unsigned int rrpc_get_pages(struct bio *bio)
{
	return  bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
}

static inline sector_t rrpc_get_sector(sector_t laddr)
{
	return laddr * NR_PHY_IN_LOG;
}

static inline int request_intersects(struct rrpc_inflight_rq *r,
				sector_t laddr_start, sector_t laddr_end)
{
	return (laddr_end >= r->l_start) && (laddr_start <= r->l_end);
}

static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
			     unsigned int pages, struct rrpc_inflight_rq *r)
{
	sector_t laddr_end = laddr + pages - 1;
	struct rrpc_inflight_rq *rtmp;

	WARN_ON(irqs_disabled());

	spin_lock_irq(&rrpc->inflights.lock);
	list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
		if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
			/* existing, overlapping request, come back later */
			spin_unlock_irq(&rrpc->inflights.lock);
			return 1;
		}
	}

	r->l_start = laddr;
	r->l_end = laddr_end;

	list_add_tail(&r->list, &rrpc->inflights.reqs);
	spin_unlock_irq(&rrpc->inflights.lock);
	return 0;
}

static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
				 unsigned int pages,
				 struct rrpc_inflight_rq *r)
{
	BUG_ON((laddr + pages) > rrpc->nr_sects);

	return __rrpc_lock_laddr(rrpc, laddr, pages, r);
}

static inline struct rrpc_inflight_rq *rrpc_get_inflight_rq(struct nvm_rq *rqd)
{
	struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);

	return &rrqd->inflight_rq;
}

static inline int rrpc_lock_rq(struct rrpc *rrpc, struct bio *bio,
							struct nvm_rq *rqd)
{
	sector_t laddr = rrpc_get_laddr(bio);
	unsigned int pages = rrpc_get_pages(bio);
	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);

	return rrpc_lock_laddr(rrpc, laddr, pages, r);
}

static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
						struct rrpc_inflight_rq *r)
{
	unsigned long flags;

	spin_lock_irqsave(&rrpc->inflights.lock, flags);
	list_del_init(&r->list);
	spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
}

static inline void rrpc_unlock_rq(struct rrpc *rrpc, struct nvm_rq *rqd)
{
	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
	uint8_t pages = rqd->nr_ppas;

	BUG_ON((r->l_start + pages) > rrpc->nr_sects);

	rrpc_unlock_laddr(rrpc, r);
}

#endif /* RRPC_H_ */
Commit	Line	Data
ae1519ec MB	1	/*
	2	* Copyright (C) 2015 IT University of Copenhagen
	3	* Initial release: Matias Bjorling <m@bjorling.me>
	4	*
	5	* This program is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU General Public License version
	7	* 2 as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful, but
	10	* WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	* General Public License for more details.
	13	*
	14	* Implementation of a Round-robin page-based Hybrid FTL for Open-channel SSDs.
	15	*/
	16
	17	#ifndef RRPC_H_
	18	#define RRPC_H_
	19
	20	#include <linux/blkdev.h>
	21	#include <linux/blk-mq.h>
	22	#include <linux/bio.h>
	23	#include <linux/module.h>
	24	#include <linux/kthread.h>
	25	#include <linux/vmalloc.h>
	26
	27	#include <linux/lightnvm.h>
	28
	29	/* Run only GC if less than 1/X blocks are free */
	30	#define GC_LIMIT_INVERSE 10
	31	#define GC_TIME_SECS 100
	32
	33	#define RRPC_SECTOR (512)
	34	#define RRPC_EXPOSED_PAGE_SIZE (4096)
	35
	36	#define NR_PHY_IN_LOG (RRPC_EXPOSED_PAGE_SIZE / RRPC_SECTOR)
	37
	38	struct rrpc_inflight {
	39	struct list_head reqs;
	40	spinlock_t lock;
	41	};
	42
	43	struct rrpc_inflight_rq {
	44	struct list_head list;
	45	sector_t l_start;
	46	sector_t l_end;
	47	};
	48
	49	struct rrpc_rq {
	50	struct rrpc_inflight_rq inflight_rq;
	51	struct rrpc_addr *addr;
	52	unsigned long flags;
	53	};
	54
	55	struct rrpc_block {
	56	struct nvm_block *parent;
d7a64d27	57	struct rrpc_lun *rlun;
ae1519ec MB	58	struct list_head prio;
	59
	60	#define MAX_INVALID_PAGES_STORAGE 8
	61	/* Bitmap for invalid page intries */
	62	unsigned long invalid_pages[MAX_INVALID_PAGES_STORAGE];
	63	/* points to the next writable page within a block */
	64	unsigned int next_page;
	65	/* number of pages that are invalid, wrt host page size */
	66	unsigned int nr_invalid_pages;
	67
	68	spinlock_t lock;
	69	atomic_t data_cmnt_size; /* data pages committed to stable storage */
	70	};
	71
	72	struct rrpc_lun {
	73	struct rrpc *rrpc;
	74	struct nvm_lun *parent;
	75	struct rrpc_block cur, gc_cur;
	76	struct rrpc_block blocks; / Reference to block allocation */
ff0e498b JG	77
ff0e498b JG	78	struct list_head prio_list; /* Blocks that may be GC'ed */
ff0e498b	79
ae1519ec MB	80	struct work_struct ws_gc;
	81
	82	spinlock_t lock;
	83	};
	84
	85	struct rrpc {
	86	/* instance must be kept in top to resolve rrpc in unprep */
	87	struct nvm_tgt_instance instance;
	88
	89	struct nvm_dev *dev;
	90	struct gendisk *disk;
	91
4c9dacb8	92	sector_t soffset; /* logical sector offset */
b7ceb7d5	93	u64 poffset; /* physical page offset */
ae1519ec MB	94	int lun_offset;
	95
	96	int nr_luns;
	97	struct rrpc_lun *luns;
	98
	99	/* calculated values */
4ece44af	100	unsigned long long nr_sects;
ae1519ec MB	101	unsigned long total_blocks;
	102
	103	/* Write strategy variables. Move these into each for structure for each
	104	* strategy
	105	*/
	106	atomic_t next_lun; /* Whenever a page is written, this is updated
	107	* to point to the next write lun
	108	*/
	109
	110	spinlock_t bio_lock;
	111	struct bio_list requeue_bios;
	112	struct work_struct ws_requeue;
	113
	114	/* Simple translation map of logical addresses to physical addresses.
	115	* The logical addresses is known by the host system, while the physical
	116	* addresses are used when writing to the disk block device.
	117	*/
	118	struct rrpc_addr *trans_map;
	119	/* also store a reverse map for garbage collection */
	120	struct rrpc_rev_addr *rev_trans_map;
	121	spinlock_t rev_lock;
	122
	123	struct rrpc_inflight inflights;
	124
	125	mempool_t *addr_pool;
	126	mempool_t *page_pool;
	127	mempool_t *gcb_pool;
	128	mempool_t *rq_pool;
	129
	130	struct timer_list gc_timer;
	131	struct workqueue_struct *krqd_wq;
	132	struct workqueue_struct *kgc_wq;
	133	};
	134
	135	struct rrpc_block_gc {
	136	struct rrpc *rrpc;
	137	struct rrpc_block *rblk;
	138	struct work_struct ws_gc;
	139	};
	140
	141	/* Logical to physical mapping */
	142	struct rrpc_addr {
b7ceb7d5	143	u64 addr;
ae1519ec MB	144	struct rrpc_block *rblk;
	145	};
	146
	147	/* Physical to logical mapping */
	148	struct rrpc_rev_addr {
b7ceb7d5	149	u64 addr;
ae1519ec MB	150	};
ae1519ec MB	151
afb18e0e JG	152	static inline struct rrpc_block rrpc_get_rblk(struct rrpc_lun rlun,
	153	int blk_id)
	154	{
	155	struct rrpc *rrpc = rlun->rrpc;
	156	int lun_blk = blk_id % rrpc->dev->blks_per_lun;
	157
	158	return &rlun->blocks[lun_blk];
	159	}
	160
ae1519ec MB	161	static inline sector_t rrpc_get_laddr(struct bio *bio)
	162	{
	163	return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
	164	}
	165
	166	static inline unsigned int rrpc_get_pages(struct bio *bio)
	167	{
	168	return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
	169	}
	170
	171	static inline sector_t rrpc_get_sector(sector_t laddr)
	172	{
	173	return laddr * NR_PHY_IN_LOG;
	174	}
	175
	176	static inline int request_intersects(struct rrpc_inflight_rq *r,
	177	sector_t laddr_start, sector_t laddr_end)
	178	{
3704e098	179	return (laddr_end >= r->l_start) && (laddr_start <= r->l_end);
ae1519ec MB	180	}
	181
	182	static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
5114e277	183	unsigned int pages, struct rrpc_inflight_rq *r)
ae1519ec MB	184	{
	185	sector_t laddr_end = laddr + pages - 1;
	186	struct rrpc_inflight_rq *rtmp;
	187
bba7f40a JG	188	WARN_ON(irqs_disabled());
bba7f40a JG	189
ae1519ec MB	190	spin_lock_irq(&rrpc->inflights.lock);
	191	list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
	192	if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
	193	/* existing, overlapping request, come back later */
	194	spin_unlock_irq(&rrpc->inflights.lock);
	195	return 1;
	196	}
	197	}
	198
	199	r->l_start = laddr;
	200	r->l_end = laddr_end;
	201
	202	list_add_tail(&r->list, &rrpc->inflights.reqs);
	203	spin_unlock_irq(&rrpc->inflights.lock);
	204	return 0;
	205	}
	206
	207	static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
5114e277	208	unsigned int pages,
ae1519ec MB	209	struct rrpc_inflight_rq *r)
ae1519ec MB	210	{
4ece44af	211	BUG_ON((laddr + pages) > rrpc->nr_sects);
ae1519ec MB	212
	213	return __rrpc_lock_laddr(rrpc, laddr, pages, r);
	214	}
	215
	216	static inline struct rrpc_inflight_rq rrpc_get_inflight_rq(struct nvm_rq rqd)
	217	{
	218	struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
	219
	220	return &rrqd->inflight_rq;
	221	}
	222
	223	static inline int rrpc_lock_rq(struct rrpc rrpc, struct bio bio,
	224	struct nvm_rq *rqd)
	225	{
	226	sector_t laddr = rrpc_get_laddr(bio);
	227	unsigned int pages = rrpc_get_pages(bio);
	228	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
	229
	230	return rrpc_lock_laddr(rrpc, laddr, pages, r);
	231	}
	232
	233	static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
	234	struct rrpc_inflight_rq *r)
	235	{
	236	unsigned long flags;
	237
	238	spin_lock_irqsave(&rrpc->inflights.lock, flags);
	239	list_del_init(&r->list);
	240	spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
	241	}
	242
	243	static inline void rrpc_unlock_rq(struct rrpc rrpc, struct nvm_rq rqd)
	244	{
	245	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
6d5be959	246	uint8_t pages = rqd->nr_ppas;
ae1519ec	247
4ece44af	248	BUG_ON((r->l_start + pages) > rrpc->nr_sects);
ae1519ec MB	249
	250	rrpc_unlock_laddr(rrpc, r);
	251	}
	252
	253	#endif /* RRPC_H_ */