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* Copyright (C) 2015 IT University of Copenhagen
* Initial release: Matias Bjorling <>
* 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
* 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_TIME_SECS 100
#define RRPC_SECTOR (512)
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;
/* 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 wblk_list; /* Queued blocks to be written to */
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;
list_for_each_entry(rtmp, &rrpc->inflights.reqs, list) {
if (unlikely(request_intersects(rtmp, laddr, laddr_end))) {
/* existing, overlapping request, come back later */
return 1;
r->l_start = laddr;
r->l_end = laddr_end;
list_add_tail(&r->list, &rrpc->inflights.reqs);
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);
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_ */