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authorJavier González <javier@javigon.com>2018-10-09 13:12:09 +0200
committerJens Axboe <axboe@kernel.dk>2018-10-09 08:25:08 -0600
commit40b8657dcc0bbd4a293cac1acd4b0b01c0359416 (patch)
tree132bc7832c197a44c16c38a59441803027fad974 /drivers/lightnvm/pblk-rb.c
parentdde4aac20babee040875f76842a31b14b76dd369 (diff)
lightnvm: pblk: encapsulate rb pointer operations
pblk's read/write buffer is always a power-of-2, thus wrapping up the buffer can be done with a bit mask. Since this is an implementation detail internal to the write buffer, make a helper that hides pointer increment + wrap, and allows to transparently relax this assumption in the future. Signed-off-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/lightnvm/pblk-rb.c')
-rw-r--r--drivers/lightnvm/pblk-rb.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/lightnvm/pblk-rb.c b/drivers/lightnvm/pblk-rb.c
index 82829e8151db..e46d8cb9d28b 100644
--- a/drivers/lightnvm/pblk-rb.c
+++ b/drivers/lightnvm/pblk-rb.c
@@ -169,6 +169,12 @@ static unsigned int pblk_rb_space(struct pblk_rb *rb)
return pblk_rb_ring_space(rb, mem, sync, rb->nr_entries);
}
+unsigned int pblk_rb_ptr_wrap(struct pblk_rb *rb, unsigned int p,
+ unsigned int nr_entries)
+{
+ return (p + nr_entries) & (rb->nr_entries - 1);
+}
+
/*
* Buffer count is calculated with respect to the submission entry signaling the
* entries that are available to send to the media
@@ -195,8 +201,7 @@ unsigned int pblk_rb_read_commit(struct pblk_rb *rb, unsigned int nr_entries)
subm = READ_ONCE(rb->subm);
/* Commit read means updating submission pointer */
- smp_store_release(&rb->subm,
- (subm + nr_entries) & (rb->nr_entries - 1));
+ smp_store_release(&rb->subm, pblk_rb_ptr_wrap(rb, subm, nr_entries));
return subm;
}
@@ -229,7 +234,7 @@ static int __pblk_rb_update_l2p(struct pblk_rb *rb, unsigned int to_update)
line = pblk_ppa_to_line(pblk, w_ctx->ppa);
kref_put(&line->ref, pblk_line_put);
clean_wctx(w_ctx);
- rb->l2p_update = (rb->l2p_update + 1) & (rb->nr_entries - 1);
+ rb->l2p_update = pblk_rb_ptr_wrap(rb, rb->l2p_update, 1);
}
pblk_rl_out(&pblk->rl, user_io, gc_io);
@@ -408,7 +413,7 @@ static int pblk_rb_may_write(struct pblk_rb *rb, unsigned int nr_entries,
return 0;
/* Protect from read count */
- smp_store_release(&rb->mem, (*pos + nr_entries) & (rb->nr_entries - 1));
+ smp_store_release(&rb->mem, pblk_rb_ptr_wrap(rb, *pos, nr_entries));
return 1;
}
@@ -432,7 +437,7 @@ static int pblk_rb_may_write_flush(struct pblk_rb *rb, unsigned int nr_entries,
if (!__pblk_rb_may_write(rb, nr_entries, pos))
return 0;
- mem = (*pos + nr_entries) & (rb->nr_entries - 1);
+ mem = pblk_rb_ptr_wrap(rb, *pos, nr_entries);
*io_ret = NVM_IO_DONE;
if (bio->bi_opf & REQ_PREFLUSH) {
@@ -572,7 +577,7 @@ try:
/* Release flags on context. Protect from writes */
smp_store_release(&entry->w_ctx.flags, flags);
- pos = (pos + 1) & (rb->nr_entries - 1);
+ pos = pblk_rb_ptr_wrap(rb, pos, 1);
}
if (pad) {
@@ -652,7 +657,7 @@ out:
struct pblk_w_ctx *pblk_rb_w_ctx(struct pblk_rb *rb, unsigned int pos)
{
- unsigned int entry = pos & (rb->nr_entries - 1);
+ unsigned int entry = pblk_rb_ptr_wrap(rb, pos, 0);
return &rb->entries[entry].w_ctx;
}
@@ -698,7 +703,7 @@ unsigned int pblk_rb_sync_advance(struct pblk_rb *rb, unsigned int nr_entries)
}
}
- sync = (sync + nr_entries) & (rb->nr_entries - 1);
+ sync = pblk_rb_ptr_wrap(rb, sync, nr_entries);
/* Protect from counts */
smp_store_release(&rb->sync, sync);