diff options
author | Javier González <javier@javigon.com> | 2018-10-09 13:12:09 +0200 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2018-10-09 08:25:08 -0600 |
commit | 40b8657dcc0bbd4a293cac1acd4b0b01c0359416 (patch) | |
tree | 132bc7832c197a44c16c38a59441803027fad974 /drivers/lightnvm/pblk-rb.c | |
parent | dde4aac20babee040875f76842a31b14b76dd369 (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.c | 21 |
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); |