From: Joel A Fernandes Subject: [PATCH v2] OMAP: AES: Don't idle/start AES device between Encrypt operations Date: Tue, 28 May 2013 19:02:55 -0500 Message-ID: <1369785775-3737-1-git-send-email-joelagnel@ti.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Herbert Xu , Joel A Fernandes To: , Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:37491 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932080Ab3E2ADG (ORCPT ); Tue, 28 May 2013 20:03:06 -0400 Sender: linux-crypto-owner@vger.kernel.org List-ID: Calling runtime PM API for every block causes serious perf hit to crypto operations that are done on a long buffer. As crypto is performed on a page boundary, encrypting large buffers can cause a series of crypto operations divided by page. The runtime PM API is also called those many times. We call runtime_pm_get_sync only at beginning on the session (cra_init) and runtime_pm_put at the end. This result in upto a 50% speedup as below. This doesn't make the driver to keep the system awake as runtime get/put is only called during a crypto session which completes usually quickly. Before: root@beagleboard:~# time -v openssl speed -evp aes-128-cbc Doing aes-128-cbc for 3s on 16 size blocks: 13310 aes-128-cbc's in 0.01s Doing aes-128-cbc for 3s on 64 size blocks: 13040 aes-128-cbc's in 0.04s Doing aes-128-cbc for 3s on 256 size blocks: 9134 aes-128-cbc's in 0.03s Doing aes-128-cbc for 3s on 1024 size blocks: 8939 aes-128-cbc's in 0.01s Doing aes-128-cbc for 3s on 8192 size blocks: 4299 aes-128-cbc's in 0.00s After: root@beagleboard:~# time -v openssl speed -evp aes-128-cbc Doing aes-128-cbc for 3s on 16 size blocks: 18911 aes-128-cbc's in 0.02s Doing aes-128-cbc for 3s on 64 size blocks: 18878 aes-128-cbc's in 0.02s Doing aes-128-cbc for 3s on 256 size blocks: 11878 aes-128-cbc's in 0.10s Doing aes-128-cbc for 3s on 1024 size blocks: 11538 aes-128-cbc's in 0.05s Doing aes-128-cbc for 3s on 8192 size blocks: 4857 aes-128-cbc's in 0.03s While at it, also drop enter and exit pr_debugs, in related code. tracers can be used for that. Tested on a Beaglebone (AM335x SoC) board. v3 changes: Refreshed patch on kernel v3.10-rc3 Signed-off-by: Joel A Fernandes --- drivers/crypto/omap-aes.c | 29 +++++++++++++++++++---------- 1 files changed, 19 insertions(+), 10 deletions(-) diff --git a/drivers/crypto/omap-aes.c b/drivers/crypto/omap-aes.c index ee15b0f..06524a0 100644 --- a/drivers/crypto/omap-aes.c +++ b/drivers/crypto/omap-aes.c @@ -203,13 +203,6 @@ static void omap_aes_write_n(struct omap_aes_dev *dd, u32 offset, static int omap_aes_hw_init(struct omap_aes_dev *dd) { - /* - * clocks are enabled when request starts and disabled when finished. - * It may be long delays between requests. - * Device might go to off mode to save power. - */ - pm_runtime_get_sync(dd->dev); - if (!(dd->flags & FLAGS_INIT)) { dd->flags |= FLAGS_INIT; dd->err = 0; @@ -636,7 +629,6 @@ static void omap_aes_finish_req(struct omap_aes_dev *dd, int err) pr_debug("err: %d\n", err); - pm_runtime_put(dd->dev); dd->flags &= ~FLAGS_BUSY; req->base.complete(&req->base, err); @@ -837,8 +829,16 @@ static int omap_aes_ctr_decrypt(struct ablkcipher_request *req) static int omap_aes_cra_init(struct crypto_tfm *tfm) { - pr_debug("enter\n"); + struct omap_aes_dev *dd = NULL; + /* Find AES device, currently picks the first device */ + spin_lock_bh(&list_lock); + list_for_each_entry(dd, &dev_list, list) { + break; + } + spin_unlock_bh(&list_lock); + + pm_runtime_get_sync(dd->dev); tfm->crt_ablkcipher.reqsize = sizeof(struct omap_aes_reqctx); return 0; @@ -846,7 +846,16 @@ static int omap_aes_cra_init(struct crypto_tfm *tfm) static void omap_aes_cra_exit(struct crypto_tfm *tfm) { - pr_debug("enter\n"); + struct omap_aes_dev *dd = NULL; + + /* Find AES device, currently picks the first device */ + spin_lock_bh(&list_lock); + list_for_each_entry(dd, &dev_list, list) { + break; + } + spin_unlock_bh(&list_lock); + + pm_runtime_put_sync(dd->dev); } /* ********************** ALGS ************************************ */ -- 1.7.4.1