[mirror_ubuntu-artful-kernel.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;
	unsigned long flags;
};

struct rrpc_block {
	unsigned long id;
	struct nvm_block *parent;
	struct rrpc_lun *rlun;

	struct list_head prio;		/* LUN CG list */
	struct list_head list;		/* LUN free, used, bb list */

#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;

	int state;

	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 list_head wblk_list;	/* Queued blocks to be written to */

	struct work_struct ws_gc;

	int reserved_blocks;

	spinlock_t lock;
};

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

	struct nvm_tgt_dev *dev;
	struct gendisk *disk;

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

	int nr_luns;
	struct rrpc_lun *luns;

	/* calculated values */
	unsigned long long nr_sects;

	/* 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;
	struct nvm_tgt_dev *dev = rrpc->dev;
	int lun_blk = blk_id % dev->geo.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;
ae1519ec MB	51	unsigned long flags;
	52	};
	53
	54	struct rrpc_block {
8e79b5cb	55	unsigned long id;
ae1519ec	56	struct nvm_block *parent;
d7a64d27	57	struct rrpc_lun *rlun;
8e79b5cb JG	58
	59	struct list_head prio; /* LUN CG list */
	60	struct list_head list; /* LUN free, used, bb list */
ae1519ec MB	61
	62	#define MAX_INVALID_PAGES_STORAGE 8
	63	/* Bitmap for invalid page intries */
	64	unsigned long invalid_pages[MAX_INVALID_PAGES_STORAGE];
	65	/* points to the next writable page within a block */
	66	unsigned int next_page;
	67	/* number of pages that are invalid, wrt host page size */
	68	unsigned int nr_invalid_pages;
	69
8e79b5cb JG	70	int state;
8e79b5cb JG	71
ae1519ec MB	72	spinlock_t lock;
	73	atomic_t data_cmnt_size; /* data pages committed to stable storage */
	74	};
	75
	76	struct rrpc_lun {
	77	struct rrpc *rrpc;
	78	struct nvm_lun *parent;
8e79b5cb	79
ae1519ec MB	80	struct rrpc_block cur, gc_cur;
ae1519ec MB	81	struct rrpc_block blocks; / Reference to block allocation */
ff0e498b JG	82
ff0e498b JG	83	struct list_head prio_list; /* Blocks that may be GC'ed */
855cdd2c	84	struct list_head wblk_list; /* Queued blocks to be written to */
ff0e498b	85
ae1519ec MB	86	struct work_struct ws_gc;
ae1519ec MB	87
8e79b5cb JG	88	int reserved_blocks;
8e79b5cb JG	89
ae1519ec MB	90	spinlock_t lock;
	91	};
	92
	93	struct rrpc {
	94	/* instance must be kept in top to resolve rrpc in unprep */
	95	struct nvm_tgt_instance instance;
	96
8e79b5cb	97	struct nvm_tgt_dev *dev;
ae1519ec MB	98	struct gendisk *disk;
ae1519ec MB	99
4c9dacb8	100	sector_t soffset; /* logical sector offset */
b7ceb7d5	101	u64 poffset; /* physical page offset */
ae1519ec MB	102
	103	int nr_luns;
	104	struct rrpc_lun *luns;
	105
	106	/* calculated values */
4ece44af	107	unsigned long long nr_sects;
ae1519ec MB	108
	109	/* Write strategy variables. Move these into each for structure for each
	110	* strategy
	111	*/
	112	atomic_t next_lun; /* Whenever a page is written, this is updated
	113	* to point to the next write lun
	114	*/
	115
	116	spinlock_t bio_lock;
	117	struct bio_list requeue_bios;
	118	struct work_struct ws_requeue;
	119
	120	/* Simple translation map of logical addresses to physical addresses.
	121	* The logical addresses is known by the host system, while the physical
	122	* addresses are used when writing to the disk block device.
	123	*/
	124	struct rrpc_addr *trans_map;
	125	/* also store a reverse map for garbage collection */
	126	struct rrpc_rev_addr *rev_trans_map;
	127	spinlock_t rev_lock;
	128
	129	struct rrpc_inflight inflights;
	130
	131	mempool_t *addr_pool;
	132	mempool_t *page_pool;
	133	mempool_t *gcb_pool;
	134	mempool_t *rq_pool;
	135
	136	struct timer_list gc_timer;
	137	struct workqueue_struct *krqd_wq;
	138	struct workqueue_struct *kgc_wq;
	139	};
	140
	141	struct rrpc_block_gc {
	142	struct rrpc *rrpc;
	143	struct rrpc_block *rblk;
	144	struct work_struct ws_gc;
	145	};
	146
	147	/* Logical to physical mapping */
	148	struct rrpc_addr {
b7ceb7d5	149	u64 addr;
ae1519ec MB	150	struct rrpc_block *rblk;
	151	};
	152
	153	/* Physical to logical mapping */
	154	struct rrpc_rev_addr {
b7ceb7d5	155	u64 addr;
ae1519ec MB	156	};
ae1519ec MB	157
afb18e0e JG	158	static inline struct rrpc_block rrpc_get_rblk(struct rrpc_lun rlun,
	159	int blk_id)
	160	{
	161	struct rrpc *rrpc = rlun->rrpc;
8e79b5cb JG	162	struct nvm_tgt_dev *dev = rrpc->dev;
8e79b5cb JG	163	int lun_blk = blk_id % dev->geo.blks_per_lun;
afb18e0e JG	164
	165	return &rlun->blocks[lun_blk];
	166	}
	167
ae1519ec MB	168	static inline sector_t rrpc_get_laddr(struct bio *bio)
	169	{
	170	return bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
	171	}
	172
	173	static inline unsigned int rrpc_get_pages(struct bio *bio)
	174	{
	175	return bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
	176	}
	177
	178	static inline sector_t rrpc_get_sector(sector_t laddr)
	179	{
	180	return laddr * NR_PHY_IN_LOG;
	181	}
	182
	183	static inline int request_intersects(struct rrpc_inflight_rq *r,
	184	sector_t laddr_start, sector_t laddr_end)
	185	{
3704e098	186	return (laddr_end >= r->l_start) && (laddr_start <= r->l_end);
ae1519ec MB	187	}
	188
	189	static int __rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
5114e277	190	unsigned int pages, struct rrpc_inflight_rq *r)
ae1519ec MB	191	{
	192	sector_t laddr_end = laddr + pages - 1;
	193	struct rrpc_inflight_rq *rtmp;
	194
bba7f40a JG	195	WARN_ON(irqs_disabled());
bba7f40a JG	196
ae1519ec MB	197	spin_lock_irq(&rrpc->inflights.lock);
	198	list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
	199	if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
	200	/* existing, overlapping request, come back later */
	201	spin_unlock_irq(&rrpc->inflights.lock);
	202	return 1;
	203	}
	204	}
	205
	206	r->l_start = laddr;
	207	r->l_end = laddr_end;
	208
	209	list_add_tail(&r->list, &rrpc->inflights.reqs);
	210	spin_unlock_irq(&rrpc->inflights.lock);
	211	return 0;
	212	}
	213
	214	static inline int rrpc_lock_laddr(struct rrpc *rrpc, sector_t laddr,
5114e277	215	unsigned int pages,
ae1519ec MB	216	struct rrpc_inflight_rq *r)
ae1519ec MB	217	{
4ece44af	218	BUG_ON((laddr + pages) > rrpc->nr_sects);
ae1519ec MB	219
	220	return __rrpc_lock_laddr(rrpc, laddr, pages, r);
	221	}
	222
	223	static inline struct rrpc_inflight_rq rrpc_get_inflight_rq(struct nvm_rq rqd)
	224	{
	225	struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
	226
	227	return &rrqd->inflight_rq;
	228	}
	229
	230	static inline int rrpc_lock_rq(struct rrpc rrpc, struct bio bio,
	231	struct nvm_rq *rqd)
	232	{
	233	sector_t laddr = rrpc_get_laddr(bio);
	234	unsigned int pages = rrpc_get_pages(bio);
	235	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
	236
	237	return rrpc_lock_laddr(rrpc, laddr, pages, r);
	238	}
	239
	240	static inline void rrpc_unlock_laddr(struct rrpc *rrpc,
	241	struct rrpc_inflight_rq *r)
	242	{
	243	unsigned long flags;
	244
	245	spin_lock_irqsave(&rrpc->inflights.lock, flags);
	246	list_del_init(&r->list);
	247	spin_unlock_irqrestore(&rrpc->inflights.lock, flags);
	248	}
	249
	250	static inline void rrpc_unlock_rq(struct rrpc rrpc, struct nvm_rq rqd)
	251	{
	252	struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
6d5be959	253	uint8_t pages = rqd->nr_ppas;
ae1519ec	254
4ece44af	255	BUG_ON((r->l_start + pages) > rrpc->nr_sects);
ae1519ec MB	256
	257	rrpc_unlock_laddr(rrpc, r);
	258	}
	259
	260	#endif /* RRPC_H_ */