From 1e8e55b67030c6a2fef893d428bdcd611f73705c Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 29 Nov 2017 15:41:04 +0200 Subject: mmc: block: Add CQE support Add CQE support to the block driver, including: - optionally using DCMD for flush requests - "manually" issuing discard requests - issuing read / write requests to the CQE - supporting block-layer timeouts - handling recovery - supporting re-tuning CQE offers 25% - 50% better random multi-threaded I/O. There is a slight (e.g. 2%) drop in sequential read speed but no observable change to sequential write. CQE automatically sends the commands to complete requests. However it only supports reads / writes and so-called "direct commands" (DCMD). Furthermore DCMD is limited to one command at a time, but discards require 3 commands. That makes issuing discards through CQE very awkward, but some CQE's don't support DCMD anyway. So for discards, the existing non-CQE approach is taken, where the mmc core code issues the 3 commands one at a time i.e. mmc_erase(). Where DCMD is used, is for issuing flushes. Signed-off-by: Adrian Hunter Acked-by: Linus Walleij Signed-off-by: Ulf Hansson Tested-by: Linus Walleij --- drivers/mmc/core/block.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/mmc/core/block.h') diff --git a/drivers/mmc/core/block.h b/drivers/mmc/core/block.h index 6d34e87b18f6..f472ce5d5647 100644 --- a/drivers/mmc/core/block.h +++ b/drivers/mmc/core/block.h @@ -7,6 +7,8 @@ struct request; void mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req); +void mmc_blk_cqe_recovery(struct mmc_queue *mq); + enum mmc_issued; enum mmc_issued mmc_blk_mq_issue_rq(struct mmc_queue *mq, struct request *req); -- cgit v1.2.3