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=-11.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLACK autolearn=unavailable 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 3F35DC433B4 for ; Thu, 22 Apr 2021 06:51:26 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 79C046145C for ; Thu, 22 Apr 2021 06:51:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 79C046145C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FQp3v6BPhz304T for ; Thu, 22 Apr 2021 16:51:23 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=QXom36jW; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::72f; helo=mail-qk1-x72f.google.com; envelope-from=leobras.c@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=QXom36jW; dkim-atps=neutral Received: from mail-qk1-x72f.google.com (mail-qk1-x72f.google.com [IPv6:2607:f8b0:4864:20::72f]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FQp3P0ksvz2xZS for ; Thu, 22 Apr 2021 16:50:54 +1000 (AEST) Received: by mail-qk1-x72f.google.com with SMTP id i12so13825798qke.3 for ; Wed, 21 Apr 2021 23:50:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:subject:from:to:cc:date:in-reply-to:references :organization:user-agent:mime-version:content-transfer-encoding; bh=rtDdixl50dEInzVU4EDqe3HYgm+3xRTbWaZMtMKGnEc=; b=QXom36jWadvPIRGrs6Z2HWLbuunYIqK2QOPmciTq88qx2jsOebC974zCrnaAarbfbG j75FeLb+ks56iceff2Dh8PPqP6/FceRxw1neJq91ABd7OqjH9F1CWI3Tm9pdW/Igy9JF 6duOLpbEWybYFPYgNfPPaUI6JtkGHsVRYXw8pmT4+bXPJf0hEgn3PQYNWwujW5F3YQgh VIIKnmQTYuOrQSwhEsr8t6WS16rBO5Nf7WXkefGe4H8frfwxKssrCMeA3h8KEhSiQrAK Ti8TO/VIr2ryDuJyOB7q8J/vGoefSS0gpwkGxNvPPfgM7nZdVYNNOr8YHZIOleYK3nHN Ojbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:organization:user-agent:mime-version :content-transfer-encoding; bh=rtDdixl50dEInzVU4EDqe3HYgm+3xRTbWaZMtMKGnEc=; b=YjWHvDPWVyzM5C5OvnooweFqlUeqR4xaXMNW6mYN7IHLKgUHCHetGWKpKqGoq3NAWQ Kr5HO/vU33lfZLGpOmSIWYJjH/cNOg79nUx8Wgm+yUSNpgh5bbFLrB0UgZrWkxZGIJip CLx0YU/HoHkRyzLKs2K3d2hUxTkMyTRCnmVqwNpyA1Wv2VZYxVYhlV0XrPFD5Hdv3lZY WYsmz7Rx9jhc8Wf04wa7AVOTFOpkT3Tv7dgd4sYZDfxL6aSm0pyzzaDhJMs8DoTleJ6D FJZva5SHxdgqiuDzyhoEglBQggoMYCqliaE2XrAakyPEKoTdbF1PqMRj47oe/FGbmDdE sIEw== X-Gm-Message-State: AOAM5318k3VtNPpp2bQMMWa75CFkER1OhrZd13bNKDzaayWP5AadhD02 0AIvPYsFsx0JV9oShoHFAh4= X-Google-Smtp-Source: ABdhPJzAFcrT+Qs+l8dTqvqGJX/aDrzfuZm1NwaJkPi+txCgsMnq4XFAgQ5Q9uiBRDrcKkbFLxwUkw== X-Received: by 2002:a05:620a:579:: with SMTP id p25mr2113901qkp.95.1619074249026; Wed, 21 Apr 2021 23:50:49 -0700 (PDT) Received: from li-908e0a4c-2250-11b2-a85c-f027e903211b.ibm.com ([177.35.200.187]) by smtp.gmail.com with ESMTPSA id l12sm1562269qtq.34.2021.04.21.23.50.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Apr 2021 23:50:48 -0700 (PDT) Message-ID: Subject: Re: [PATCH 1/1] powerpc/kernel/iommu: Use largepool as a last resort when !largealloc From: Leonardo Bras To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Alexey Kardashevskiy , Niklas Schnelle , Nicolin Chen Date: Thu, 22 Apr 2021 03:50:44 -0300 In-Reply-To: <20210318174414.684630-2-leobras.c@gmail.com> References: <20210318174414.684630-1-leobras.c@gmail.com> <20210318174414.684630-2-leobras.c@gmail.com> Organization: IBM Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Hello, FYI: This patch was reviewed when it was part of another patchset: http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20200817234033.442511-4-leobras.c@gmail.com/ On Thu, 2021-03-18 at 14:44 -0300, Leonardo Bras wrote: > As of today, doing iommu_range_alloc() only for !largealloc (npages <= 15) > will only be able to use 3/4 of the available pages, given pages on > largepool not being available for !largealloc. > > This could mean some drivers not being able to fully use all the available > pages for the DMA window. > > Add pages on largepool as a last resort for !largealloc, making all pages > of the DMA window available. > > Signed-off-by: Leonardo Bras > Reviewed-by: Alexey Kardashevskiy > --- >  arch/powerpc/kernel/iommu.c | 9 +++++++++ >  1 file changed, 9 insertions(+) > > diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c > index 3329ef045805..ae6ad8dca605 100644 > --- a/arch/powerpc/kernel/iommu.c > +++ b/arch/powerpc/kernel/iommu.c > @@ -255,6 +255,15 @@ static unsigned long iommu_range_alloc(struct device *dev, >   pass++; >   goto again; >   > > + } else if (pass == tbl->nr_pools + 1) { > + /* Last resort: try largepool */ > + spin_unlock(&pool->lock); > + pool = &tbl->large_pool; > + spin_lock(&pool->lock); > + pool->hint = pool->start; > + pass++; > + goto again; > + >   } else { >   /* Give up */ >   spin_unlock_irqrestore(&(pool->lock), flags);