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=-15.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 480EBC48BE5 for ; Thu, 17 Jun 2021 00:47:41 +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 99F7C613B9 for ; Thu, 17 Jun 2021 00:47:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 99F7C613B9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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 4G53LN0TCyz3c1V for ; Thu, 17 Jun 2021 10:47:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=rMohPe+t; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=sstabellini@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=rMohPe+t; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4G53Kr2Nfsz306m for ; Thu, 17 Jun 2021 10:47:12 +1000 (AEST) Received: by mail.kernel.org (Postfix) with ESMTPSA id C7A2B613B9; Thu, 17 Jun 2021 00:47:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623890829; bh=WCzGPQl/aym123sINb8QnvJYTwJNBRaVx2zLf3Bv1N8=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=rMohPe+tbKQa0AYXnI+IW3OaFUpO6B0eUu0gZForopqzfrCjPyFI1Ewjobgur6/dk bLRtb8PIYvryWZweFMXTwAbMWtg0nctMUoV8kxk6uELmUKnBiVw5LeKCqL5SBhOByE jiTek0nnewDrHmhCidXDSQ3WaahCsU5g4GDabRezUbSedVXgMEydAYEHuXFwzTS91g cJMCyter7dx77I2E16IUKEfK8pcdYqTSbuwilDTS8T+uuTkXRJvXElaDgqvBEXf5YU 0wAWL6nOk87f0a1jJqezXJtxglL4nvT9peSjxOtxRa83ff4UqBDa3CGXSoXj4TqnFN tHVw/jZbmu50w== Date: Wed, 16 Jun 2021 17:47:07 -0700 (PDT) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-T480s To: Claire Chang Subject: Re: [PATCH v12 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing In-Reply-To: <20210616062157.953777-7-tientzu@chromium.org> Message-ID: References: <20210616062157.953777-1-tientzu@chromium.org> <20210616062157.953777-7-tientzu@chromium.org> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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: heikki.krogerus@linux.intel.com, thomas.hellstrom@linux.intel.com, peterz@infradead.org, joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, Frank Rowand , mingo@kernel.org, Marek Szyprowski , sstabellini@kernel.org, Saravana Kannan , Joerg Roedel , "Rafael J . Wysocki" , Christoph Hellwig , Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Thierry Reding , intel-gfx@lists.freedesktop.org, matthew.auld@intel.com, linux-devicetree , jxgao@google.com, daniel@ffwll.ch, Will Deacon , Konrad Rzeszutek Wilk , maarten.lankhorst@linux.intel.com, airlied@linux.ie, Dan Williams , linuxppc-dev@lists.ozlabs.org, jani.nikula@linux.intel.com, Rob Herring , rodrigo.vivi@intel.com, bhelgaas@google.com, boris.ostrovsky@oracle.com, Andy Shevchenko , jgross@suse.com, Nicolas Boichat , Greg KH , Randy Dunlap , lkml , tfiga@chromium.org, "list@263.net:IOMMU DRIVERS" , Jim Quinlan , xypron.glpk@gmx.de, Robin Murphy , bauerman@linux.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, 16 Jun 2021, Claire Chang wrote: > Propagate the swiotlb_force into io_tlb_default_mem->force_bounce and > use it to determine whether to bounce the data or not. This will be > useful later to allow for different pools. > > Signed-off-by: Claire Chang > --- > include/linux/swiotlb.h | 11 +++++++++++ > kernel/dma/direct.c | 2 +- > kernel/dma/direct.h | 2 +- > kernel/dma/swiotlb.c | 4 ++++ > 4 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index dd1c30a83058..8d8855c77d9a 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -84,6 +84,7 @@ extern enum swiotlb_force swiotlb_force; > * unmap calls. > * @debugfs: The dentry to debugfs. > * @late_alloc: %true if allocated using the page allocator > + * @force_bounce: %true if swiotlb bouncing is forced > */ > struct io_tlb_mem { > phys_addr_t start; > @@ -94,6 +95,7 @@ struct io_tlb_mem { > spinlock_t lock; > struct dentry *debugfs; > bool late_alloc; > + bool force_bounce; > struct io_tlb_slot { > phys_addr_t orig_addr; > size_t alloc_size; > @@ -109,6 +111,11 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) > return mem && paddr >= mem->start && paddr < mem->end; > } > > +static inline bool is_swiotlb_force_bounce(struct device *dev) > +{ > + return dev->dma_io_tlb_mem->force_bounce; > +} > void __init swiotlb_exit(void); > unsigned int swiotlb_max_segment(void); > size_t swiotlb_max_mapping_size(struct device *dev); > @@ -120,6 +127,10 @@ static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) > { > return false; > } > +static inline bool is_swiotlb_force_bounce(struct device *dev) > +{ > + return false; > +} > static inline void swiotlb_exit(void) > { > } > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 7a88c34d0867..a92465b4eb12 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -496,7 +496,7 @@ size_t dma_direct_max_mapping_size(struct device *dev) > { > /* If SWIOTLB is active, use its maximum mapping size */ > if (is_swiotlb_active(dev) && > - (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE)) > + (dma_addressing_limited(dev) || is_swiotlb_force_bounce(dev))) > return swiotlb_max_mapping_size(dev); > return SIZE_MAX; > } > diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h > index 13e9e7158d94..4632b0f4f72e 100644 > --- a/kernel/dma/direct.h > +++ b/kernel/dma/direct.h > @@ -87,7 +87,7 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev, > phys_addr_t phys = page_to_phys(page) + offset; > dma_addr_t dma_addr = phys_to_dma(dev, phys); > > - if (unlikely(swiotlb_force == SWIOTLB_FORCE)) > + if (is_swiotlb_force_bounce(dev)) > return swiotlb_map(dev, phys, size, dir, attrs); > > if (unlikely(!dma_capable(dev, dma_addr, size, true))) { Should we also make the same change in drivers/xen/swiotlb-xen.c:xen_swiotlb_map_page ? If I make that change, I can see that everything is working as expected for a restricted-dma device with Linux running as dom0 on Xen. However, is_swiotlb_force_bounce returns non-zero even for normal non-restricted-dma devices. That shouldn't happen, right? It looks like struct io_tlb_slot is not zeroed on allocation. Adding memset(mem, 0x0, struct_size) in swiotlb_late_init_with_tbl solves the issue. With those two changes, the series passes my tests and you can add my tested-by.