blob: d8c75958ced346d5aede0398a8f4b50bd96fa749 [file] [log] [blame]
/*
* 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.
*/
#include "rrpc.h"
static struct kmem_cache *rrpc_gcb_cache, *rrpc_rq_cache;
static DECLARE_RWSEM(rrpc_lock);
static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
struct nvm_rq *rqd, unsigned long flags);
#define rrpc_for_each_lun(rrpc, rlun, i) \
for ((i) = 0, rlun = &(rrpc)->luns[0]; \
(i) < (rrpc)->nr_luns; (i)++, rlun = &(rrpc)->luns[(i)])
static void rrpc_page_invalidate(struct rrpc *rrpc, struct rrpc_addr *a)
{
struct rrpc_block *rblk = a->rblk;
unsigned int pg_offset;
lockdep_assert_held(&rrpc->rev_lock);
if (a->addr == ADDR_EMPTY || !rblk)
return;
spin_lock(&rblk->lock);
div_u64_rem(a->addr, rrpc->dev->pgs_per_blk, &pg_offset);
WARN_ON(test_and_set_bit(pg_offset, rblk->invalid_pages));
rblk->nr_invalid_pages++;
spin_unlock(&rblk->lock);
rrpc->rev_trans_map[a->addr - rrpc->poffset].addr = ADDR_EMPTY;
}
static void rrpc_invalidate_range(struct rrpc *rrpc, sector_t slba,
unsigned len)
{
sector_t i;
spin_lock(&rrpc->rev_lock);
for (i = slba; i < slba + len; i++) {
struct rrpc_addr *gp = &rrpc->trans_map[i];
rrpc_page_invalidate(rrpc, gp);
gp->rblk = NULL;
}
spin_unlock(&rrpc->rev_lock);
}
static struct nvm_rq *rrpc_inflight_laddr_acquire(struct rrpc *rrpc,
sector_t laddr, unsigned int pages)
{
struct nvm_rq *rqd;
struct rrpc_inflight_rq *inf;
rqd = mempool_alloc(rrpc->rq_pool, GFP_ATOMIC);
if (!rqd)
return ERR_PTR(-ENOMEM);
inf = rrpc_get_inflight_rq(rqd);
if (rrpc_lock_laddr(rrpc, laddr, pages, inf)) {
mempool_free(rqd, rrpc->rq_pool);
return NULL;
}
return rqd;
}
static void rrpc_inflight_laddr_release(struct rrpc *rrpc, struct nvm_rq *rqd)
{
struct rrpc_inflight_rq *inf = rrpc_get_inflight_rq(rqd);
rrpc_unlock_laddr(rrpc, inf);
mempool_free(rqd, rrpc->rq_pool);
}
static void rrpc_discard(struct rrpc *rrpc, struct bio *bio)
{
sector_t slba = bio->bi_iter.bi_sector / NR_PHY_IN_LOG;
sector_t len = bio->bi_iter.bi_size / RRPC_EXPOSED_PAGE_SIZE;
struct nvm_rq *rqd;
do {
rqd = rrpc_inflight_laddr_acquire(rrpc, slba, len);
schedule();
} while (!rqd);
if (IS_ERR(rqd)) {
pr_err("rrpc: unable to acquire inflight IO\n");
bio_io_error(bio);
return;
}
rrpc_invalidate_range(rrpc, slba, len);
rrpc_inflight_laddr_release(rrpc, rqd);
}
static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk)
{
return (rblk->next_page == rrpc->dev->pgs_per_blk);
}
static u64 block_to_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
{
struct nvm_block *blk = rblk->parent;
return blk->id * rrpc->dev->pgs_per_blk;
}
static struct ppa_addr linear_to_generic_addr(struct nvm_dev *dev,
struct ppa_addr r)
{
struct ppa_addr l;
int secs, pgs, blks, luns;
sector_t ppa = r.ppa;
l.ppa = 0;
div_u64_rem(ppa, dev->sec_per_pg, &secs);
l.g.sec = secs;
sector_div(ppa, dev->sec_per_pg);
div_u64_rem(ppa, dev->sec_per_blk, &pgs);
l.g.pg = pgs;
sector_div(ppa, dev->pgs_per_blk);
div_u64_rem(ppa, dev->blks_per_lun, &blks);
l.g.blk = blks;
sector_div(ppa, dev->blks_per_lun);
div_u64_rem(ppa, dev->luns_per_chnl, &luns);
l.g.lun = luns;
sector_div(ppa, dev->luns_per_chnl);
l.g.ch = ppa;
return l;
}
static struct ppa_addr rrpc_ppa_to_gaddr(struct nvm_dev *dev, u64 addr)
{
struct ppa_addr paddr;
paddr.ppa = addr;
return linear_to_generic_addr(dev, paddr);
}
/* requires lun->lock taken */
static void rrpc_set_lun_cur(struct rrpc_lun *rlun, struct rrpc_block *rblk)
{
struct rrpc *rrpc = rlun->rrpc;
BUG_ON(!rblk);
if (rlun->cur) {
spin_lock(&rlun->cur->lock);
WARN_ON(!block_is_full(rrpc, rlun->cur));
spin_unlock(&rlun->cur->lock);
}
rlun->cur = rblk;
}
static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
unsigned long flags)
{
struct nvm_lun *lun = rlun->parent;
struct nvm_block *blk;
struct rrpc_block *rblk;
spin_lock(&lun->lock);
blk = nvm_get_blk_unlocked(rrpc->dev, rlun->parent, flags);
if (!blk) {
pr_err("nvm: rrpc: cannot get new block from media manager\n");
spin_unlock(&lun->lock);
return NULL;
}
rblk = &rlun->blocks[blk->id];
list_add_tail(&rblk->list, &rlun->open_list);
spin_unlock(&lun->lock);
blk->priv = rblk;
bitmap_zero(rblk->invalid_pages, rrpc->dev->pgs_per_blk);
rblk->next_page = 0;
rblk->nr_invalid_pages = 0;
atomic_set(&rblk->data_cmnt_size, 0);
return rblk;
}
static void rrpc_put_blk(struct rrpc *rrpc, struct rrpc_block *rblk)
{
struct rrpc_lun *rlun = rblk->rlun;
struct nvm_lun *lun = rlun->parent;
spin_lock(&lun->lock);
nvm_put_blk_unlocked(rrpc->dev, rblk->parent);
list_del(&rblk->list);
spin_unlock(&lun->lock);
}
static void rrpc_put_blks(struct rrpc *rrpc)
{
struct rrpc_lun *rlun;
int i;
for (i = 0; i < rrpc->nr_luns; i++) {
rlun = &rrpc->luns[i];
if (rlun->cur)
rrpc_put_blk(rrpc, rlun->cur);
if (rlun->gc_cur)
rrpc_put_blk(rrpc, rlun->gc_cur);
}
}
static struct rrpc_lun *get_next_lun(struct rrpc *rrpc)
{
int next = atomic_inc_return(&rrpc->next_lun);
return &rrpc->luns[next % rrpc->nr_luns];
}
static void rrpc_gc_kick(struct rrpc *rrpc)
{
struct rrpc_lun *rlun;
unsigned int i;
for (i = 0; i < rrpc->nr_luns; i++) {
rlun = &rrpc->luns[i];
queue_work(rrpc->krqd_wq, &rlun->ws_gc);
}
}
/*
* timed GC every interval.
*/
static void rrpc_gc_timer(unsigned long data)
{
struct rrpc *rrpc = (struct rrpc *)data;
rrpc_gc_kick(rrpc);
mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
}
static void rrpc_end_sync_bio(struct bio *bio)
{
struct completion *waiting = bio->bi_private;
if (bio->bi_error)
pr_err("nvm: gc request failed (%u).\n", bio->bi_error);
complete(waiting);
}
/*
* rrpc_move_valid_pages -- migrate live data off the block
* @rrpc: the 'rrpc' structure
* @block: the block from which to migrate live pages
*
* Description:
* GC algorithms may call this function to migrate remaining live
* pages off the block prior to erasing it. This function blocks
* further execution until the operation is complete.
*/
static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
{
struct request_queue *q = rrpc->dev->q;
struct rrpc_rev_addr *rev;
struct nvm_rq *rqd;
struct bio *bio;
struct page *page;
int slot;
int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
u64 phys_addr;
DECLARE_COMPLETION_ONSTACK(wait);
if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
return 0;
bio = bio_alloc(GFP_NOIO, 1);
if (!bio) {
pr_err("nvm: could not alloc bio to gc\n");
return -ENOMEM;
}
page = mempool_alloc(rrpc->page_pool, GFP_NOIO);
if (!page)
return -ENOMEM;
while ((slot = find_first_zero_bit(rblk->invalid_pages,
nr_pgs_per_blk)) < nr_pgs_per_blk) {
/* Lock laddr */
phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
try:
spin_lock(&rrpc->rev_lock);
/* Get logical address from physical to logical table */
rev = &rrpc->rev_trans_map[phys_addr - rrpc->poffset];
/* already updated by previous regular write */
if (rev->addr == ADDR_EMPTY) {
spin_unlock(&rrpc->rev_lock);
continue;
}
rqd = rrpc_inflight_laddr_acquire(rrpc, rev->addr, 1);
if (IS_ERR_OR_NULL(rqd)) {
spin_unlock(&rrpc->rev_lock);
schedule();
goto try;
}
spin_unlock(&rrpc->rev_lock);
/* Perform read to do GC */
bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
bio->bi_rw = READ;
bio->bi_private = &wait;
bio->bi_end_io = rrpc_end_sync_bio;
/* TODO: may fail when EXP_PG_SIZE > PAGE_SIZE */
bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
pr_err("rrpc: gc read failed.\n");
rrpc_inflight_laddr_release(rrpc, rqd);
goto finished;
}
wait_for_completion_io(&wait);
if (bio->bi_error) {
rrpc_inflight_laddr_release(rrpc, rqd);
goto finished;
}
bio_reset(bio);
reinit_completion(&wait);
bio->bi_iter.bi_sector = rrpc_get_sector(rev->addr);
bio->bi_rw = WRITE;
bio->bi_private = &wait;
bio->bi_end_io = rrpc_end_sync_bio;
bio_add_pc_page(q, bio, page, RRPC_EXPOSED_PAGE_SIZE, 0);
/* turn the command around and write the data back to a new
* address
*/
if (rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_GC)) {
pr_err("rrpc: gc write failed.\n");
rrpc_inflight_laddr_release(rrpc, rqd);
goto finished;
}
wait_for_completion_io(&wait);
rrpc_inflight_laddr_release(rrpc, rqd);
if (bio->bi_error)
goto finished;
bio_reset(bio);
}
finished:
mempool_free(page, rrpc->page_pool);
bio_put(bio);
if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
pr_err("nvm: failed to garbage collect block\n");
return -EIO;
}
return 0;
}
static void rrpc_block_gc(struct work_struct *work)
{
struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
ws_gc);
struct rrpc *rrpc = gcb->rrpc;
struct rrpc_block *rblk = gcb->rblk;
struct nvm_dev *dev = rrpc->dev;
struct nvm_lun *lun = rblk->parent->lun;
struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
mempool_free(gcb, rrpc->gcb_pool);
pr_debug("nvm: block '%lu' being reclaimed\n", rblk->parent->id);
if (rrpc_move_valid_pages(rrpc, rblk))
goto put_back;
if (nvm_erase_blk(dev, rblk->parent))
goto put_back;
rrpc_put_blk(rrpc, rblk);
return;
put_back:
spin_lock(&rlun->lock);
list_add_tail(&rblk->prio, &rlun->prio_list);
spin_unlock(&rlun->lock);
}
/* the block with highest number of invalid pages, will be in the beginning
* of the list
*/
static struct rrpc_block *rblock_max_invalid(struct rrpc_block *ra,
struct rrpc_block *rb)
{
if (ra->nr_invalid_pages == rb->nr_invalid_pages)
return ra;
return (ra->nr_invalid_pages < rb->nr_invalid_pages) ? rb : ra;
}
/* linearly find the block with highest number of invalid pages
* requires lun->lock
*/
static struct rrpc_block *block_prio_find_max(struct rrpc_lun *rlun)
{
struct list_head *prio_list = &rlun->prio_list;
struct rrpc_block *rblock, *max;
BUG_ON(list_empty(prio_list));
max = list_first_entry(prio_list, struct rrpc_block, prio);
list_for_each_entry(rblock, prio_list, prio)
max = rblock_max_invalid(max, rblock);
return max;
}
static void rrpc_lun_gc(struct work_struct *work)
{
struct rrpc_lun *rlun = container_of(work, struct rrpc_lun, ws_gc);
struct rrpc *rrpc = rlun->rrpc;
struct nvm_lun *lun = rlun->parent;
struct rrpc_block_gc *gcb;
unsigned int nr_blocks_need;
nr_blocks_need = rrpc->dev->blks_per_lun / GC_LIMIT_INVERSE;
if (nr_blocks_need < rrpc->nr_luns)
nr_blocks_need = rrpc->nr_luns;
spin_lock(&rlun->lock);
while (nr_blocks_need > lun->nr_free_blocks &&
!list_empty(&rlun->prio_list)) {
struct rrpc_block *rblock = block_prio_find_max(rlun);
struct nvm_block *block = rblock->parent;
if (!rblock->nr_invalid_pages)
break;
gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
if (!gcb)
break;
list_del_init(&rblock->prio);
BUG_ON(!block_is_full(rrpc, rblock));
pr_debug("rrpc: selected block '%lu' for GC\n", block->id);
gcb->rrpc = rrpc;
gcb->rblk = rblock;
INIT_WORK(&gcb->ws_gc, rrpc_block_gc);
queue_work(rrpc->kgc_wq, &gcb->ws_gc);
nr_blocks_need--;
}
spin_unlock(&rlun->lock);
/* TODO: Hint that request queue can be started again */
}
static void rrpc_gc_queue(struct work_struct *work)
{
struct rrpc_block_gc *gcb = container_of(work, struct rrpc_block_gc,
ws_gc);
struct rrpc *rrpc = gcb->rrpc;
struct rrpc_block *rblk = gcb->rblk;
struct nvm_lun *lun = rblk->parent->lun;
struct rrpc_lun *rlun = &rrpc->luns[lun->id - rrpc->lun_offset];
spin_lock(&rlun->lock);
list_add_tail(&rblk->prio, &rlun->prio_list);
spin_unlock(&rlun->lock);
mempool_free(gcb, rrpc->gcb_pool);
pr_debug("nvm: block '%lu' is full, allow GC (sched)\n",
rblk->parent->id);
}
static const struct block_device_operations rrpc_fops = {
.owner = THIS_MODULE,
};
static struct rrpc_lun *rrpc_get_lun_rr(struct rrpc *rrpc, int is_gc)
{
unsigned int i;
struct rrpc_lun *rlun, *max_free;
if (!is_gc)
return get_next_lun(rrpc);
/* during GC, we don't care about RR, instead we want to make
* sure that we maintain evenness between the block luns.
*/
max_free = &rrpc->luns[0];
/* prevent GC-ing lun from devouring pages of a lun with
* little free blocks. We don't take the lock as we only need an
* estimate.
*/
rrpc_for_each_lun(rrpc, rlun, i) {
if (rlun->parent->nr_free_blocks >
max_free->parent->nr_free_blocks)
max_free = rlun;
}
return max_free;
}
static struct rrpc_addr *rrpc_update_map(struct rrpc *rrpc, sector_t laddr,
struct rrpc_block *rblk, u64 paddr)
{
struct rrpc_addr *gp;
struct rrpc_rev_addr *rev;
BUG_ON(laddr >= rrpc->nr_pages);
gp = &rrpc->trans_map[laddr];
spin_lock(&rrpc->rev_lock);
if (gp->rblk)
rrpc_page_invalidate(rrpc, gp);
gp->addr = paddr;
gp->rblk = rblk;
rev = &rrpc->rev_trans_map[gp->addr - rrpc->poffset];
rev->addr = laddr;
spin_unlock(&rrpc->rev_lock);
return gp;
}
static u64 rrpc_alloc_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
{
u64 addr = ADDR_EMPTY;
spin_lock(&rblk->lock);
if (block_is_full(rrpc, rblk))
goto out;
addr = block_to_addr(rrpc, rblk) + rblk->next_page;
rblk->next_page++;
out:
spin_unlock(&rblk->lock);
return addr;
}
/* Simple round-robin Logical to physical address translation.
*
* Retrieve the mapping using the active append point. Then update the ap for
* the next write to the disk.
*
* Returns rrpc_addr with the physical address and block. Remember to return to
* rrpc->addr_cache when request is finished.
*/
static struct rrpc_addr *rrpc_map_page(struct rrpc *rrpc, sector_t laddr,
int is_gc)
{
struct rrpc_lun *rlun;
struct rrpc_block *rblk;
struct nvm_lun *lun;
u64 paddr;
rlun = rrpc_get_lun_rr(rrpc, is_gc);
lun = rlun->parent;
if (!is_gc && lun->nr_free_blocks < rrpc->nr_luns * 4)
return NULL;
spin_lock(&rlun->lock);
rblk = rlun->cur;
retry:
paddr = rrpc_alloc_addr(rrpc, rblk);
if (paddr == ADDR_EMPTY) {
rblk = rrpc_get_blk(rrpc, rlun, 0);
if (rblk) {
rrpc_set_lun_cur(rlun, rblk);
goto retry;
}
if (is_gc) {
/* retry from emergency gc block */
paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
if (paddr == ADDR_EMPTY) {
rblk = rrpc_get_blk(rrpc, rlun, 1);
if (!rblk) {
pr_err("rrpc: no more blocks");
goto err;
}
rlun->gc_cur = rblk;
paddr = rrpc_alloc_addr(rrpc, rlun->gc_cur);
}
rblk = rlun->gc_cur;
}
}
spin_unlock(&rlun->lock);
return rrpc_update_map(rrpc, laddr, rblk, paddr);
err:
spin_unlock(&rlun->lock);
return NULL;
}
static void rrpc_run_gc(struct rrpc *rrpc, struct rrpc_block *rblk)
{
struct rrpc_block_gc *gcb;
gcb = mempool_alloc(rrpc->gcb_pool, GFP_ATOMIC);
if (!gcb) {
pr_err("rrpc: unable to queue block for gc.");
return;
}
gcb->rrpc = rrpc;
gcb->rblk = rblk;
INIT_WORK(&gcb->ws_gc, rrpc_gc_queue);
queue_work(rrpc->kgc_wq, &gcb->ws_gc);
}
static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
sector_t laddr, uint8_t npages)
{
struct rrpc_addr *p;
struct rrpc_block *rblk;
struct nvm_lun *lun;
int cmnt_size, i;
for (i = 0; i < npages; i++) {
p = &rrpc->trans_map[laddr + i];
rblk = p->rblk;
lun = rblk->parent->lun;
cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk)) {
struct nvm_block *blk = rblk->parent;
struct rrpc_lun *rlun = rblk->rlun;
spin_lock(&lun->lock);
lun->nr_open_blocks--;
lun->nr_closed_blocks++;
blk->state &= ~NVM_BLK_ST_OPEN;
blk->state |= NVM_BLK_ST_CLOSED;
list_move_tail(&rblk->list, &rlun->closed_list);
spin_unlock(&lun->lock);
rrpc_run_gc(rrpc, rblk);
}
}
}
static void rrpc_end_io(struct nvm_rq *rqd)
{
struct rrpc *rrpc = container_of(rqd->ins, struct rrpc, instance);
struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
uint8_t npages = rqd->nr_pages;
sector_t laddr = rrpc_get_laddr(rqd->bio) - npages;
if (bio_data_dir(rqd->bio) == WRITE)
rrpc_end_io_write(rrpc, rrqd, laddr, npages);
bio_put(rqd->bio);
if (rrqd->flags & NVM_IOTYPE_GC)
return;
rrpc_unlock_rq(rrpc, rqd);
if (npages > 1)
nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
if (rqd->metadata)
nvm_dev_dma_free(rrpc->dev, rqd->metadata, rqd->dma_metadata);
mempool_free(rqd, rrpc->rq_pool);
}
static int rrpc_read_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
struct nvm_rq *rqd, unsigned long flags, int npages)
{
struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
struct rrpc_addr *gp;
sector_t laddr = rrpc_get_laddr(bio);
int is_gc = flags & NVM_IOTYPE_GC;
int i;
if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
return NVM_IO_REQUEUE;
}
for (i = 0; i < npages; i++) {
/* We assume that mapping occurs at 4KB granularity */
BUG_ON(!(laddr + i >= 0 && laddr + i < rrpc->nr_pages));
gp = &rrpc->trans_map[laddr + i];
if (gp->rblk) {
rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
gp->addr);
} else {
BUG_ON(is_gc);
rrpc_unlock_laddr(rrpc, r);
nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
rqd->dma_ppa_list);
return NVM_IO_DONE;
}
}
rqd->opcode = NVM_OP_HBREAD;
return NVM_IO_OK;
}
static int rrpc_read_rq(struct rrpc *rrpc, struct bio *bio, struct nvm_rq *rqd,
unsigned long flags)
{
struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
int is_gc = flags & NVM_IOTYPE_GC;
sector_t laddr = rrpc_get_laddr(bio);
struct rrpc_addr *gp;
if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
return NVM_IO_REQUEUE;
BUG_ON(!(laddr >= 0 && laddr < rrpc->nr_pages));
gp = &rrpc->trans_map[laddr];
if (gp->rblk) {
rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, gp->addr);
} else {
BUG_ON(is_gc);
rrpc_unlock_rq(rrpc, rqd);
return NVM_IO_DONE;
}
rqd->opcode = NVM_OP_HBREAD;
rrqd->addr = gp;
return NVM_IO_OK;
}
static int rrpc_write_ppalist_rq(struct rrpc *rrpc, struct bio *bio,
struct nvm_rq *rqd, unsigned long flags, int npages)
{
struct rrpc_inflight_rq *r = rrpc_get_inflight_rq(rqd);
struct rrpc_addr *p;
sector_t laddr = rrpc_get_laddr(bio);
int is_gc = flags & NVM_IOTYPE_GC;
int i;
if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd)) {
nvm_dev_dma_free(rrpc->dev, rqd->ppa_list, rqd->dma_ppa_list);
return NVM_IO_REQUEUE;
}
for (i = 0; i < npages; i++) {
/* We assume that mapping occurs at 4KB granularity */
p = rrpc_map_page(rrpc, laddr + i, is_gc);
if (!p) {
BUG_ON(is_gc);
rrpc_unlock_laddr(rrpc, r);
nvm_dev_dma_free(rrpc->dev, rqd->ppa_list,
rqd->dma_ppa_list);
rrpc_gc_kick(rrpc);
return NVM_IO_REQUEUE;
}
rqd->ppa_list[i] = rrpc_ppa_to_gaddr(rrpc->dev,
p->addr);
}
rqd->opcode = NVM_OP_HBWRITE;
return NVM_IO_OK;
}
static int rrpc_write_rq(struct rrpc *rrpc, struct bio *bio,
struct nvm_rq *rqd, unsigned long flags)
{
struct rrpc_rq *rrqd = nvm_rq_to_pdu(rqd);
struct rrpc_addr *p;
int is_gc = flags & NVM_IOTYPE_GC;
sector_t laddr = rrpc_get_laddr(bio);
if (!is_gc && rrpc_lock_rq(rrpc, bio, rqd))
return NVM_IO_REQUEUE;
p = rrpc_map_page(rrpc, laddr, is_gc);
if (!p) {
BUG_ON(is_gc);
rrpc_unlock_rq(rrpc, rqd);
rrpc_gc_kick(rrpc);
return NVM_IO_REQUEUE;
}
rqd->ppa_addr = rrpc_ppa_to_gaddr(rrpc->dev, p->addr);
rqd->opcode = NVM_OP_HBWRITE;
rrqd->addr = p;
return NVM_IO_OK;
}
static int rrpc_setup_rq(struct rrpc *rrpc, struct bio *bio,
struct nvm_rq *rqd, unsigned long flags, uint8_t npages)
{
if (npages > 1) {
rqd->ppa_list = nvm_dev_dma_alloc(rrpc->dev, GFP_KERNEL,
&rqd->dma_ppa_list);
if (!rqd->ppa_list) {
pr_err("rrpc: not able to allocate ppa list\n");
return NVM_IO_ERR;
}
if (bio_rw(bio) == WRITE)
return rrpc_write_ppalist_rq(rrpc, bio, rqd, flags,
npages);
return rrpc_read_ppalist_rq(rrpc, bio, rqd, flags, npages);
}
if (bio_rw(bio) == WRITE)
return rrpc_write_rq(rrpc, bio, rqd, flags);
return rrpc_read_rq(rrpc, bio, rqd, flags);
}
static int rrpc_submit_io(struct rrpc *rrpc, struct bio *bio,
struct nvm_rq *rqd, unsigned long flags)
{
int err;
struct rrpc_rq *rrq = nvm_rq_to_pdu(rqd);
uint8_t nr_pages = rrpc_get_pages(bio);
int bio_size = bio_sectors(bio) << 9;
if (bio_size < rrpc->dev->sec_size)
return NVM_IO_ERR;
else if (bio_size > rrpc->dev->max_rq_size)
return NVM_IO_ERR;
err = rrpc_setup_rq(rrpc, bio, rqd, flags, nr_pages);
if (err)
return err;
bio_get(bio);
rqd->bio = bio;
rqd->ins = &rrpc->instance;
rqd->nr_pages = nr_pages;
rrq->flags = flags;
err = nvm_submit_io(rrpc->dev, rqd);
if (err) {
pr_err("rrpc: I/O submission failed: %d\n", err);
bio_put(bio);
if (!(flags & NVM_IOTYPE_GC)) {
rrpc_unlock_rq(rrpc, rqd);
if (rqd->nr_pages > 1)
nvm_dev_dma_free(rrpc->dev,
rqd->ppa_list, rqd->dma_ppa_list);
}
return NVM_IO_ERR;
}
return NVM_IO_OK;
}
static blk_qc_t rrpc_make_rq(struct request_queue *q, struct bio *bio)
{
struct rrpc *rrpc = q->queuedata;
struct nvm_rq *rqd;
int err;
if (bio->bi_rw & REQ_DISCARD) {
rrpc_discard(rrpc, bio);
return BLK_QC_T_NONE;
}
rqd = mempool_alloc(rrpc->rq_pool, GFP_KERNEL);
if (!rqd) {
pr_err_ratelimited("rrpc: not able to queue bio.");
bio_io_error(bio);
return BLK_QC_T_NONE;
}
memset(rqd, 0, sizeof(struct nvm_rq));
err = rrpc_submit_io(rrpc, bio, rqd, NVM_IOTYPE_NONE);
switch (err) {
case NVM_IO_OK:
return BLK_QC_T_NONE;
case NVM_IO_ERR:
bio_io_error(bio);
break;
case NVM_IO_DONE:
bio_endio(bio);
break;
case NVM_IO_REQUEUE:
spin_lock(&rrpc->bio_lock);
bio_list_add(&rrpc->requeue_bios, bio);
spin_unlock(&rrpc->bio_lock);
queue_work(rrpc->kgc_wq, &rrpc->ws_requeue);
break;
}
mempool_free(rqd, rrpc->rq_pool);
return BLK_QC_T_NONE;
}
static void rrpc_requeue(struct work_struct *work)
{
struct rrpc *rrpc = container_of(work, struct rrpc, ws_requeue);
struct bio_list bios;
struct bio *bio;
bio_list_init(&bios);
spin_lock(&rrpc->bio_lock);
bio_list_merge(&bios, &rrpc->requeue_bios);
bio_list_init(&rrpc->requeue_bios);
spin_unlock(&rrpc->bio_lock);
while ((bio = bio_list_pop(&bios)))
rrpc_make_rq(rrpc->disk->queue, bio);
}
static void rrpc_gc_free(struct rrpc *rrpc)
{
struct rrpc_lun *rlun;
int i;
if (rrpc->krqd_wq)
destroy_workqueue(rrpc->krqd_wq);
if (rrpc->kgc_wq)
destroy_workqueue(rrpc->kgc_wq);
if (!rrpc->luns)
return;
for (i = 0; i < rrpc->nr_luns; i++) {
rlun = &rrpc->luns[i];
if (!rlun->blocks)
break;
vfree(rlun->blocks);
}
}
static int rrpc_gc_init(struct rrpc *rrpc)
{
rrpc->krqd_wq = alloc_workqueue("rrpc-lun", WQ_MEM_RECLAIM|WQ_UNBOUND,
rrpc->nr_luns);
if (!rrpc->krqd_wq)
return -ENOMEM;
rrpc->kgc_wq = alloc_workqueue("rrpc-bg", WQ_MEM_RECLAIM, 1);
if (!rrpc->kgc_wq)
return -ENOMEM;
setup_timer(&rrpc->gc_timer, rrpc_gc_timer, (unsigned long)rrpc);
return 0;
}
static void rrpc_map_free(struct rrpc *rrpc)
{
vfree(rrpc->rev_trans_map);
vfree(rrpc->trans_map);
}
static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
{
struct rrpc *rrpc = (struct rrpc *)private;
struct nvm_dev *dev = rrpc->dev;
struct rrpc_addr *addr = rrpc->trans_map + slba;
struct rrpc_rev_addr *raddr = rrpc->rev_trans_map;
sector_t max_pages = dev->total_pages * (dev->sec_size >> 9);
u64 elba = slba + nlb;
u64 i;
if (unlikely(elba > dev->total_pages)) {
pr_err("nvm: L2P data from device is out of bounds!\n");
return -EINVAL;
}
for (i = 0; i < nlb; i++) {
u64 pba = le64_to_cpu(entries[i]);
/* LNVM treats address-spaces as silos, LBA and PBA are
* equally large and zero-indexed.
*/
if (unlikely(pba >= max_pages && pba != U64_MAX)) {
pr_err("nvm: L2P data entry is out of bounds!\n");
return -EINVAL;
}
/* Address zero is a special one. The first page on a disk is
* protected. As it often holds internal device boot
* information.
*/
if (!pba)
continue;
addr[i].addr = pba;
raddr[pba].addr = slba + i;
}
return 0;
}
static int rrpc_map_init(struct rrpc *rrpc)
{
struct nvm_dev *dev = rrpc->dev;
sector_t i;
int ret;
rrpc->trans_map = vzalloc(sizeof(struct rrpc_addr) * rrpc->nr_pages);
if (!rrpc->trans_map)
return -ENOMEM;
rrpc->rev_trans_map = vmalloc(sizeof(struct rrpc_rev_addr)
* rrpc->nr_pages);
if (!rrpc->rev_trans_map)
return -ENOMEM;
for (i = 0; i < rrpc->nr_pages; i++) {
struct rrpc_addr *p = &rrpc->trans_map[i];
struct rrpc_rev_addr *r = &rrpc->rev_trans_map[i];
p->addr = ADDR_EMPTY;
r->addr = ADDR_EMPTY;
}
if (!dev->ops->get_l2p_tbl)
return 0;
/* Bring up the mapping table from device */
ret = dev->ops->get_l2p_tbl(dev, 0, dev->total_pages,
rrpc_l2p_update, rrpc);
if (ret) {
pr_err("nvm: rrpc: could not read L2P table.\n");
return -EINVAL;
}
return 0;
}
/* Minimum pages needed within a lun */
#define PAGE_POOL_SIZE 16
#define ADDR_POOL_SIZE 64
static int rrpc_core_init(struct rrpc *rrpc)
{
down_write(&rrpc_lock);
if (!rrpc_gcb_cache) {
rrpc_gcb_cache = kmem_cache_create("rrpc_gcb",
sizeof(struct rrpc_block_gc), 0, 0, NULL);
if (!rrpc_gcb_cache) {
up_write(&rrpc_lock);
return -ENOMEM;
}
rrpc_rq_cache = kmem_cache_create("rrpc_rq",
sizeof(struct nvm_rq) + sizeof(struct rrpc_rq),
0, 0, NULL);
if (!rrpc_rq_cache) {
kmem_cache_destroy(rrpc_gcb_cache);
up_write(&rrpc_lock);
return -ENOMEM;
}
}
up_write(&rrpc_lock);
rrpc->page_pool = mempool_create_page_pool(PAGE_POOL_SIZE, 0);
if (!rrpc->page_pool)
return -ENOMEM;
rrpc->gcb_pool = mempool_create_slab_pool(rrpc->dev->nr_luns,
rrpc_gcb_cache);
if (!rrpc->gcb_pool)
return -ENOMEM;
rrpc->rq_pool = mempool_create_slab_pool(64, rrpc_rq_cache);
if (!rrpc->rq_pool)
return -ENOMEM;
spin_lock_init(&rrpc->inflights.lock);
INIT_LIST_HEAD(&rrpc->inflights.reqs);
return 0;
}
static void rrpc_core_free(struct rrpc *rrpc)
{
mempool_destroy(rrpc->page_pool);
mempool_destroy(rrpc->gcb_pool);
mempool_destroy(rrpc->rq_pool);
}
static void rrpc_luns_free(struct rrpc *rrpc)
{
kfree(rrpc->luns);
}
static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
{
struct nvm_dev *dev = rrpc->dev;
struct rrpc_lun *rlun;
int i, j;
if (dev->pgs_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
pr_err("rrpc: number of pages per block too high.");
return -EINVAL;
}
spin_lock_init(&rrpc->rev_lock);
rrpc->luns = kcalloc(rrpc->nr_luns, sizeof(struct rrpc_lun),
GFP_KERNEL);
if (!rrpc->luns)
return -ENOMEM;
/* 1:1 mapping */
for (i = 0; i < rrpc->nr_luns; i++) {
struct nvm_lun *lun = dev->mt->get_lun(dev, lun_begin + i);
rlun = &rrpc->luns[i];
rlun->rrpc = rrpc;
rlun->parent = lun;
INIT_LIST_HEAD(&rlun->prio_list);
INIT_LIST_HEAD(&rlun->open_list);
INIT_LIST_HEAD(&rlun->closed_list);
INIT_WORK(&rlun->ws_gc, rrpc_lun_gc);
spin_lock_init(&rlun->lock);
rrpc->total_blocks += dev->blks_per_lun;
rrpc->nr_pages += dev->sec_per_lun;
rlun->blocks = vzalloc(sizeof(struct rrpc_block) *
rrpc->dev->blks_per_lun);
if (!rlun->blocks)
goto err;
for (j = 0; j < rrpc->dev->blks_per_lun; j++) {
struct rrpc_block *rblk = &rlun->blocks[j];
struct nvm_block *blk = &lun->blocks[j];
rblk->parent = blk;
rblk->rlun = rlun;
INIT_LIST_HEAD(&rblk->prio);
spin_lock_init(&rblk->lock);
}
}
return 0;
err:
return -ENOMEM;
}
static void rrpc_free(struct rrpc *rrpc)
{
rrpc_gc_free(rrpc);
rrpc_map_free(rrpc);
rrpc_core_free(rrpc);
rrpc_luns_free(rrpc);
kfree(rrpc);
}
static void rrpc_exit(void *private)
{
struct rrpc *rrpc = private;
del_timer(&rrpc->gc_timer);
flush_workqueue(rrpc->krqd_wq);
flush_workqueue(rrpc->kgc_wq);
rrpc_free(rrpc);
}
static sector_t rrpc_capacity(void *private)
{
struct rrpc *rrpc = private;
struct nvm_dev *dev = rrpc->dev;
sector_t reserved, provisioned;
/* cur, gc, and two emergency blocks for each lun */
reserved = rrpc->nr_luns * dev->max_pages_per_blk * 4;
provisioned = rrpc->nr_pages - reserved;
if (reserved > rrpc->nr_pages) {
pr_err("rrpc: not enough space available to expose storage.\n");
return 0;
}
sector_div(provisioned, 10);
return provisioned * 9 * NR_PHY_IN_LOG;
}
/*
* Looks up the logical address from reverse trans map and check if its valid by
* comparing the logical to physical address with the physical address.
* Returns 0 on free, otherwise 1 if in use
*/
static void rrpc_block_map_update(struct rrpc *rrpc, struct rrpc_block *rblk)
{
struct nvm_dev *dev = rrpc->dev;
int offset;
struct rrpc_addr *laddr;
u64 paddr, pladdr;
for (offset = 0; offset < dev->pgs_per_blk; offset++) {
paddr = block_to_addr(rrpc, rblk) + offset;
pladdr = rrpc->rev_trans_map[paddr].addr;
if (pladdr == ADDR_EMPTY)
continue;
laddr = &rrpc->trans_map[pladdr];
if (paddr == laddr->addr) {
laddr->rblk = rblk;
} else {
set_bit(offset, rblk->invalid_pages);
rblk->nr_invalid_pages++;
}
}
}
static int rrpc_blocks_init(struct rrpc *rrpc)
{
struct rrpc_lun *rlun;
struct rrpc_block *rblk;
int lun_iter, blk_iter;
for (lun_iter = 0; lun_iter < rrpc->nr_luns; lun_iter++) {
rlun = &rrpc->luns[lun_iter];
for (blk_iter = 0; blk_iter < rrpc->dev->blks_per_lun;
blk_iter++) {
rblk = &rlun->blocks[blk_iter];
rrpc_block_map_update(rrpc, rblk);
}
}
return 0;
}
static int rrpc_luns_configure(struct rrpc *rrpc)
{
struct rrpc_lun *rlun;
struct rrpc_block *rblk;
int i;
for (i = 0; i < rrpc->nr_luns; i++) {
rlun = &rrpc->luns[i];
rblk = rrpc_get_blk(rrpc, rlun, 0);
if (!rblk)
goto err;
rrpc_set_lun_cur(rlun, rblk);
/* Emergency gc block */
rblk = rrpc_get_blk(rrpc, rlun, 1);
if (!rblk)
goto err;
rlun->gc_cur = rblk;
}
return 0;
err:
rrpc_put_blks(rrpc);
return -EINVAL;
}
static struct nvm_tgt_type tt_rrpc;
static void *rrpc_init(struct nvm_dev *dev, struct gendisk *tdisk,
int lun_begin, int lun_end)
{
struct request_queue *bqueue = dev->q;
struct request_queue *tqueue = tdisk->queue;
struct rrpc *rrpc;
int ret;
if (!(dev->identity.dom & NVM_RSP_L2P)) {
pr_err("nvm: rrpc: device does not support l2p (%x)\n",
dev->identity.dom);
return ERR_PTR(-EINVAL);
}
rrpc = kzalloc(sizeof(struct rrpc), GFP_KERNEL);
if (!rrpc)
return ERR_PTR(-ENOMEM);
rrpc->instance.tt = &tt_rrpc;
rrpc->dev = dev;
rrpc->disk = tdisk;
bio_list_init(&rrpc->requeue_bios);
spin_lock_init(&rrpc->bio_lock);
INIT_WORK(&rrpc->ws_requeue, rrpc_requeue);
rrpc->nr_luns = lun_end - lun_begin + 1;
/* simple round-robin strategy */
atomic_set(&rrpc->next_lun, -1);
ret = rrpc_luns_init(rrpc, lun_begin, lun_end);
if (ret) {
pr_err("nvm: rrpc: could not initialize luns\n");
goto err;
}
rrpc->poffset = dev->sec_per_lun * lun_begin;
rrpc->lun_offset = lun_begin;
ret = rrpc_core_init(rrpc);
if (ret) {
pr_err("nvm: rrpc: could not initialize core\n");
goto err;
}
ret = rrpc_map_init(rrpc);
if (ret) {
pr_err("nvm: rrpc: could not initialize maps\n");
goto err;
}
ret = rrpc_blocks_init(rrpc);
if (ret) {
pr_err("nvm: rrpc: could not initialize state for blocks\n");
goto err;
}
ret = rrpc_luns_configure(rrpc);
if (ret) {
pr_err("nvm: rrpc: not enough blocks available in LUNs.\n");
goto err;
}
ret = rrpc_gc_init(rrpc);
if (ret) {
pr_err("nvm: rrpc: could not initialize gc\n");
goto err;
}
/* 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));
pr_info("nvm: rrpc initialized with %u luns and %llu pages.\n",
rrpc->nr_luns, (unsigned long long)rrpc->nr_pages);
mod_timer(&rrpc->gc_timer, jiffies + msecs_to_jiffies(10));
return rrpc;
err:
rrpc_free(rrpc);
return ERR_PTR(ret);
}
/* round robin, page-based FTL, and cost-based GC */
static struct nvm_tgt_type tt_rrpc = {
.name = "rrpc",
.version = {1, 0, 0},
.make_rq = rrpc_make_rq,
.capacity = rrpc_capacity,
.end_io = rrpc_end_io,
.init = rrpc_init,
.exit = rrpc_exit,
};
static int __init rrpc_module_init(void)
{
return nvm_register_target(&tt_rrpc);
}
static void rrpc_module_exit(void)
{
nvm_unregister_target(&tt_rrpc);
}
module_init(rrpc_module_init);
module_exit(rrpc_module_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Block-Device Target for Open-Channel SSDs");