[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;
	struct list_head 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;

	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 open_list;	/* In-use open blocks. These are blocks
					 * that can be both written to and read
					 * from
					 */
	struct list_head closed_list;	/* In-use closed blocks. These are
					 * blocks that can _only_ be read from
					 */

	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;

	u64 poffset; /* physical page offset */
	int lun_offset;

	int nr_luns;
	struct rrpc_lun *luns;

	/* calculated values */
	unsigned long long nr_pages;
	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 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 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 pages,
				 struct rrpc_inflight_rq *r)
{
	BUG_ON((laddr + pages) > rrpc->nr_pages);

	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_pages;

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

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