From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE51CC43219 for ; Thu, 24 Nov 2022 10:20:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229685AbiKXKUz (ORCPT ); Thu, 24 Nov 2022 05:20:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229683AbiKXKUy (ORCPT ); Thu, 24 Nov 2022 05:20:54 -0500 X-Greylist: delayed 873 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 24 Nov 2022 02:20:53 PST Received: from stargate.chelsio.com (stargate.chelsio.com [12.32.117.8]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CAAB6129C3F for ; Thu, 24 Nov 2022 02:20:53 -0800 (PST) Received: from [10.193.177.140] (vinoth-r.asicdesigners.com [10.193.177.140] (may be forged)) by stargate.chelsio.com (8.14.7/8.14.7) with ESMTP id 2AOA62QU007818; Thu, 24 Nov 2022 02:06:05 -0800 Message-ID: <84b22219-20e1-4b18-cbab-0b77b47f9051@chelsio.com> Date: Thu, 24 Nov 2022 16:26:42 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH v2 net-next 1/6] ch_ktls: Use memcpy_from_page() instead of k[un]map_atomic() Content-Language: en-US To: Anirudh Venkataramanan , netdev@vger.kernel.org Cc: Ira Weiny , "Fabio M . De Francesco" References: <20221123205219.31748-1-anirudh.venkataramanan@intel.com> <20221123205219.31748-2-anirudh.venkataramanan@intel.com> From: Ayush Sawal In-Reply-To: <20221123205219.31748-2-anirudh.venkataramanan@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Antivirus: Avast (VPS 221124-0, 11/24/2022), Outbound message X-Antivirus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 11/24/2022 2:22 AM, Anirudh Venkataramanan wrote: > kmap_atomic() is being deprecated in favor of kmap_local_page(). Replace > the map-memcpy-unmap usage pattern (done using k[un]map_atomic()) with > memcpy_from_page(), which internally uses kmap_local_page() and > kunmap_local(). This renders the variables 'data' and 'vaddr' unnecessary, > and so remove these too. > > Note that kmap_atomic() disables preemption and page-fault processing, but > kmap_local_page() doesn't. When converting uses of kmap_atomic(), one has > to check if the code being executed between the map/unmap implicitly > depends on page-faults and/or preemption being disabled. If yes, then code > to disable page-faults and/or preemption should also be added for > functional correctness. That however doesn't appear to be the case here, > so just memcpy_from_page() is used. > > Also note that the page being mapped is not allocated by the driver, and so > the driver doesn't know if the page is in normal memory. This is the reason > kmap_local_page() is used (via memcpy_from_page()) as opposed to > page_address(). > > I don't have hardware, so this change has only been compile tested. > > Cc: Ayush Sawal > Cc: Ira Weiny > Cc: Fabio M. De Francesco > Suggested-by: Fabio M. De Francesco > Signed-off-by: Anirudh Venkataramanan > --- > v1 -> v2: > Use memcpy_from_page() as suggested by Fabio > Add a "Suggested-by" tag > Rework commit message > Some emails cc'd in v1 are defunct. Drop them. The MAINTAINERS file for > Chelsio drivers likely needs an update > --- Thanks for the patch. Acked-by: Ayush Sawal > .../chelsio/inline_crypto/ch_ktls/chcr_ktls.c | 26 +++++++++---------- > 1 file changed, 12 insertions(+), 14 deletions(-) > > diff --git a/drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c b/drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c > index da9973b..1a5fdd7 100644 > --- a/drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c > +++ b/drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c > @@ -1839,9 +1839,7 @@ static int chcr_short_record_handler(struct chcr_ktls_info *tx_info, > */ > if (prior_data_len) { > int i = 0; > - u8 *data = NULL; > skb_frag_t *f; > - u8 *vaddr; > int frag_size = 0, frag_delta = 0; > > while (remaining > 0) { > @@ -1853,24 +1851,24 @@ static int chcr_short_record_handler(struct chcr_ktls_info *tx_info, > i++; > } > f = &record->frags[i]; > - vaddr = kmap_atomic(skb_frag_page(f)); > - > - data = vaddr + skb_frag_off(f) + remaining; > frag_delta = skb_frag_size(f) - remaining; > > if (frag_delta >= prior_data_len) { > - memcpy(prior_data, data, prior_data_len); > - kunmap_atomic(vaddr); > + memcpy_from_page(prior_data, skb_frag_page(f), > + skb_frag_off(f) + remaining, > + prior_data_len); > } else { > - memcpy(prior_data, data, frag_delta); > - kunmap_atomic(vaddr); > + memcpy_from_page(prior_data, skb_frag_page(f), > + skb_frag_off(f) + remaining, > + frag_delta); > + > /* get the next page */ > f = &record->frags[i + 1]; > - vaddr = kmap_atomic(skb_frag_page(f)); > - data = vaddr + skb_frag_off(f); > - memcpy(prior_data + frag_delta, > - data, (prior_data_len - frag_delta)); > - kunmap_atomic(vaddr); > + > + memcpy_from_page(prior_data + frag_delta, > + skb_frag_page(f), > + skb_frag_off(f), > + prior_data_len - frag_delta); > } > /* reset tcp_seq as per the prior_data_required len */ > tcp_seq -= prior_data_len; -- This email has been checked for viruses by Avast antivirus software. www.avast.com