On 3/5/2019 9:00 AM, Vakul Garg wrote:
> Instead of reading job ring's occupancy registers for every req/rsp
> enqueued/dequeued respectively, we read these registers once and store
> them in memory. After completing a job enqueue/dequeue, we decrement
> these values. When these values become zero, we refresh the snapshot of
> job ring's occupancy registers. This eliminates need of expensive device
> register read operations for every job enqueued and dequeued and hence
> makes caam_jr_enqueue() and caam_jr_dequeue() faster.
>
How expensive?
Please share the case you benchmarked and performance improvement you noticed.
Somewhat related: it seems that after commit a0ca6ca022ac ("crypto: caam - one
tasklet per job ring") the "outlock" spinlock could be removed, this being a
good candidate for further improvement.
> Signed-off-by: Vakul Garg <vakul.garg@xxxxxxx>
> ---
> drivers/crypto/caam/intern.h | 1 +
> drivers/crypto/caam/jr.c | 12 ++++++++++--
> 2 files changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/crypto/caam/intern.h b/drivers/crypto/caam/intern.h
> index 5869ad58d497..b6d96e2ecf4c 100644
> --- a/drivers/crypto/caam/intern.h
> +++ b/drivers/crypto/caam/intern.h
> @@ -59,6 +59,7 @@ struct caam_drv_private_jr {
> int out_ring_read_index; /* Output index "tail" */
> int tail; /* entinfo (s/w ring) tail index */
> struct jr_outentry *outring; /* Base of output ring, DMA-safe */
> + u32 inpring_avail; /* Number of free entries in i/p ring*/
Locality: this should be near the other enqueue-related structure members.
Nitpick: use "input" instead of "i/p".
Thanks,
Horia
