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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94C41C43331 for ; Wed, 13 Nov 2019 08:29:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6ABCA222D3 for ; Wed, 13 Nov 2019 08:29:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eR/R0+XX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726505AbfKMI3X (ORCPT ); Wed, 13 Nov 2019 03:29:23 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:35352 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725966AbfKMI3W (ORCPT ); Wed, 13 Nov 2019 03:29:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573633761; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=s1akMTlo+i8m4HmhAJ7H+DLpdqdkV4atkZW1vivI704=; b=eR/R0+XXt5W1LREqJkZvCUYvQCPkFm320DpXAU3oS1XsLYr9MdIzbR++y8FQqlQe8+vGdZ Jw7aSJ4eGkFwYVN8S3WOe75jj9GUQ7RrKMhQDs0lXbq3PxrRpL5fRGmmU+9cHtI3bbXYIN uzZT+qrd7Lx+stX04PU1nqmv45wLddg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-100-Basd25mzMJCLetYnItVzrA-1; Wed, 13 Nov 2019 03:29:20 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 042D4DBE6; Wed, 13 Nov 2019 08:29:19 +0000 (UTC) Received: from carbon (ovpn-200-19.brq.redhat.com [10.40.200.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 22C8C60C85; Wed, 13 Nov 2019 08:29:08 +0000 (UTC) Date: Wed, 13 Nov 2019 09:29:07 +0100 From: Jesper Dangaard Brouer To: Lorenzo Bianconi Cc: netdev@vger.kernel.org, lorenzo.bianconi@redhat.com, davem@davemloft.net, thomas.petazzoni@bootlin.com, ilias.apalodimas@linaro.org, matteo.croce@redhat.com, brouer@redhat.com Subject: Re: [PATCH net-next 2/3] net: page_pool: add the possibility to sync DMA memory for non-coherent devices Message-ID: <20191113092907.569f6b8e@carbon> In-Reply-To: <68229f90060d01c1457ac945b2f6524e2aa27d05.1573383212.git.lorenzo@kernel.org> References: <68229f90060d01c1457ac945b2f6524e2aa27d05.1573383212.git.lorenzo@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: Basd25mzMJCLetYnItVzrA-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, 10 Nov 2019 14:09:09 +0200 Lorenzo Bianconi wrote: > diff --git a/include/net/page_pool.h b/include/net/page_pool.h > index 2cbcdbdec254..defbfd90ab46 100644 [...] > @@ -150,8 +153,8 @@ static inline void page_pool_destroy(struct page_pool= *pool) > } > =20 > /* Never call this directly, use helpers below */ > -void __page_pool_put_page(struct page_pool *pool, > -=09=09=09 struct page *page, bool allow_direct); > +void __page_pool_put_page(struct page_pool *pool, struct page *page, > +=09=09=09 unsigned int dma_sync_size, bool allow_direct); > =20 > static inline void page_pool_put_page(struct page_pool *pool, > =09=09=09=09 struct page *page, bool allow_direct) > @@ -160,14 +163,14 @@ static inline void page_pool_put_page(struct page_p= ool *pool, > =09 * allow registering MEM_TYPE_PAGE_POOL, but shield linker. > =09 */ > #ifdef CONFIG_PAGE_POOL > -=09__page_pool_put_page(pool, page, allow_direct); > +=09__page_pool_put_page(pool, page, 0, allow_direct); > #endif > } > /* Very limited use-cases allow recycle direct */ > static inline void page_pool_recycle_direct(struct page_pool *pool, > =09=09=09=09=09 struct page *page) > { > -=09__page_pool_put_page(pool, page, true); > +=09__page_pool_put_page(pool, page, 0, true); > } We need to use another "default" value than zero for 'dma_sync_size' in above calls. I suggest either 0xFFFFFFFF or -1 (which unsigned is 0xFFFFFFFF). Point is that in case caller doesn't know the length (the CPU have had access to) then page_pool will need to sync with pool->p.max_len. If choosing a larger value here default value your code below takes care of it via min(dma_sync_size, pool->p.max_len). =20 > /* API user MUST have disconnected alloc-side (not allowed to call > diff --git a/net/core/page_pool.c b/net/core/page_pool.c > index 5bc65587f1c4..af9514c2d15b 100644 > --- a/net/core/page_pool.c > +++ b/net/core/page_pool.c > @@ -112,6 +112,17 @@ static struct page > *__page_pool_get_cached(struct page_pool *pool) return page; > } > =20 > +/* Used for non-coherent devices */ > +static void page_pool_dma_sync_for_device(struct page_pool *pool, > +=09=09=09=09=09 struct page *page, > +=09=09=09=09=09 unsigned int dma_sync_size) > +{ > +=09dma_sync_size =3D min(dma_sync_size, pool->p.max_len); > +=09dma_sync_single_range_for_device(pool->p.dev, page->dma_addr, > +=09=09=09=09=09 pool->p.offset, dma_sync_size, > +=09=09=09=09=09 pool->p.dma_dir); > +} --=20 Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer