[PATCH 3/3] lightnvm: generalize rrpc ppa calculations

From: Matias BjÃrling
Date: Fri Feb 19 2016 - 07:58:21 EST


From: Javier GonzÃlez <jg@xxxxxxxxxxx>

In rrpc, some calculations assume a certain configuration (e.g., 1 LUN,
1 sector per page). The reason behind this was that LightNVM used a
simple configuration with QEMU to test core features in the beginning.
This patch relaxes these assumptions and generalizes calculation,
allowing multiple luns to be used.

Signed-off-by: Javier GonzÃlez <javier@xxxxxxxxxxxx>
Signed-off-by: Matias BjÃrling <m@xxxxxxxxxxx>
---
drivers/lightnvm/rrpc.c | 48 +++++++++++++++++++++++++++++++-----------------
drivers/lightnvm/rrpc.h | 9 +++++++++
2 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/drivers/lightnvm/rrpc.c b/drivers/lightnvm/rrpc.c
index 775bf6c2..8234378 100644
--- a/drivers/lightnvm/rrpc.c
+++ b/drivers/lightnvm/rrpc.c
@@ -38,7 +38,7 @@ static void rrpc_page_invalidate(struct rrpc *rrpc, struct rrpc_addr *a)

spin_lock(&rblk->lock);

- div_u64_rem(a->addr, rrpc->dev->pgs_per_blk, &pg_offset);
+ div_u64_rem(a->addr, rrpc->dev->sec_per_blk, &pg_offset);
WARN_ON(test_and_set_bit(pg_offset, rblk->invalid_pages));
rblk->nr_invalid_pages++;

@@ -113,14 +113,24 @@ static void rrpc_discard(struct rrpc *rrpc, struct bio *bio)

static int block_is_full(struct rrpc *rrpc, struct rrpc_block *rblk)
{
- return (rblk->next_page == rrpc->dev->pgs_per_blk);
+ return (rblk->next_page == rrpc->dev->sec_per_blk);
}

+/* Calculate relative addr for the given block, considering instantiated LUNs */
+static u64 block_to_rel_addr(struct rrpc *rrpc, struct rrpc_block *rblk)
+{
+ struct nvm_block *blk = rblk->parent;
+ int lun_blk = blk->id % (rrpc->dev->blks_per_lun * rrpc->nr_luns);
+
+ return lun_blk * rrpc->dev->sec_per_blk;
+}
+
+/* Calculate global addr for the given block */
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;
+ return blk->id * rrpc->dev->sec_per_blk;
}

static struct ppa_addr linear_to_generic_addr(struct nvm_dev *dev,
@@ -136,7 +146,7 @@ static struct ppa_addr linear_to_generic_addr(struct nvm_dev *dev,
l.g.sec = secs;

sector_div(ppa, dev->sec_per_pg);
- div_u64_rem(ppa, dev->sec_per_blk, &pgs);
+ div_u64_rem(ppa, dev->pgs_per_blk, &pgs);
l.g.pg = pgs;

sector_div(ppa, dev->pgs_per_blk);
@@ -191,12 +201,12 @@ static struct rrpc_block *rrpc_get_blk(struct rrpc *rrpc, struct rrpc_lun *rlun,
return NULL;
}

- rblk = &rlun->blocks[blk->id];
+ rblk = rrpc_get_rblk(rlun, 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);
+ bitmap_zero(rblk->invalid_pages, rrpc->dev->sec_per_blk);
rblk->next_page = 0;
rblk->nr_invalid_pages = 0;
atomic_set(&rblk->data_cmnt_size, 0);
@@ -286,11 +296,11 @@ static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
struct bio *bio;
struct page *page;
int slot;
- int nr_pgs_per_blk = rrpc->dev->pgs_per_blk;
+ int nr_sec_per_blk = rrpc->dev->sec_per_blk;
u64 phys_addr;
DECLARE_COMPLETION_ONSTACK(wait);

- if (bitmap_full(rblk->invalid_pages, nr_pgs_per_blk))
+ if (bitmap_full(rblk->invalid_pages, nr_sec_per_blk))
return 0;

bio = bio_alloc(GFP_NOIO, 1);
@@ -306,10 +316,10 @@ static int rrpc_move_valid_pages(struct rrpc *rrpc, struct rrpc_block *rblk)
}

while ((slot = find_first_zero_bit(rblk->invalid_pages,
- nr_pgs_per_blk)) < nr_pgs_per_blk) {
+ nr_sec_per_blk)) < nr_sec_per_blk) {

/* Lock laddr */
- phys_addr = (rblk->parent->id * nr_pgs_per_blk) + slot;
+ phys_addr = rblk->parent->id * nr_sec_per_blk + slot;

try:
spin_lock(&rrpc->rev_lock);
@@ -381,7 +391,7 @@ finished:
mempool_free(page, rrpc->page_pool);
bio_put(bio);

- if (!bitmap_full(rblk->invalid_pages, nr_pgs_per_blk)) {
+ if (!bitmap_full(rblk->invalid_pages, nr_sec_per_blk)) {
pr_err("nvm: failed to garbage collect block\n");
return -EIO;
}
@@ -677,7 +687,7 @@ static void rrpc_end_io_write(struct rrpc *rrpc, struct rrpc_rq *rrqd,
lun = rblk->parent->lun;

cmnt_size = atomic_inc_return(&rblk->data_cmnt_size);
- if (unlikely(cmnt_size == rrpc->dev->pgs_per_blk))
+ if (unlikely(cmnt_size == rrpc->dev->sec_per_blk))
rrpc_run_gc(rrpc, rblk);
}
}
@@ -1014,6 +1024,7 @@ static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)

for (i = 0; i < nlb; i++) {
u64 pba = le64_to_cpu(entries[i]);
+ unsigned int mod;
/* LNVM treats address-spaces as silos, LBA and PBA are
* equally large and zero-indexed.
*/
@@ -1029,8 +1040,10 @@ static int rrpc_l2p_update(u64 slba, u32 nlb, __le64 *entries, void *private)
if (!pba)
continue;

+ div_u64_rem(pba, rrpc->nr_sects, &mod);
+
addr[i].addr = pba;
- raddr[pba].addr = slba + i;
+ raddr[mod].addr = slba + i;
}

return 0;
@@ -1137,7 +1150,7 @@ static int rrpc_luns_init(struct rrpc *rrpc, int lun_begin, int lun_end)
struct rrpc_lun *rlun;
int i, j;

- if (dev->pgs_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
+ if (dev->sec_per_blk > MAX_INVALID_PAGES_STORAGE * BITS_PER_LONG) {
pr_err("rrpc: number of pages per block too high.");
return -EINVAL;
}
@@ -1238,10 +1251,11 @@ 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;
+ u64 bpaddr, paddr, pladdr;

- for (offset = 0; offset < dev->pgs_per_blk; offset++) {
- paddr = block_to_addr(rrpc, rblk) + offset;
+ bpaddr = block_to_rel_addr(rrpc, rblk);
+ for (offset = 0; offset < dev->sec_per_blk; offset++) {
+ paddr = bpaddr + offset;

pladdr = rrpc->rev_trans_map[paddr].addr;
if (pladdr == ADDR_EMPTY)
diff --git a/drivers/lightnvm/rrpc.h b/drivers/lightnvm/rrpc.h
index 3989d65..855f4a5 100644
--- a/drivers/lightnvm/rrpc.h
+++ b/drivers/lightnvm/rrpc.h
@@ -156,6 +156,15 @@ 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;
--
2.1.4