From patchwork Tue May 23 08:52:41 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 9742117 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 63AE06034C for ; Tue, 23 May 2017 08:51:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 546A426E5D for ; Tue, 23 May 2017 08:51:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 48F0D287A3; Tue, 23 May 2017 08:51:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DBC3826E5D for ; Tue, 23 May 2017 08:51:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966977AbdEWIvq (ORCPT ); Tue, 23 May 2017 04:51:46 -0400 Received: from foss.arm.com ([217.140.101.70]:47966 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966968AbdEWIvl (ORCPT ); Tue, 23 May 2017 04:51:41 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5754D344; Tue, 23 May 2017 01:51:40 -0700 (PDT) Received: from red-moon (red-moon.cambridge.arm.com [10.1.206.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 47C303F53D; Tue, 23 May 2017 01:51:36 -0700 (PDT) Date: Tue, 23 May 2017 09:52:41 +0100 From: Lorenzo Pieralisi To: Nate Watterson Cc: Sricharan R , robin.murphy@arm.com, will.deacon@arm.com, joro@8bytes.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, m.szyprowski@samsung.com, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, tn@semihalf.com, hanjun.guo@linaro.org, okaya@codeaurora.org, robh+dt@kernel.org, frowand.list@gmail.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, sudeep.holla@arm.com, rjw@rjwysocki.net, lenb@kernel.org, catalin.marinas@arm.com, arnd@arndb.de, linux-arch@vger.kernel.org, gregkh@linuxfoundation.org Subject: Re: [PATCH V11 08/11] drivers: acpi: Handle IOMMU lookup failure with deferred probing or error Message-ID: <20170523085241.GA18204@red-moon> References: <1491823266-1209-1-git-send-email-sricharan@codeaurora.org> <1491823266-1209-9-git-send-email-sricharan@codeaurora.org> <41668eff-271c-1c4c-7665-3bf0faa74669@codeaurora.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <41668eff-271c-1c4c-7665-3bf0faa74669@codeaurora.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Tue, May 23, 2017 at 02:26:10AM -0400, Nate Watterson wrote: > Hi Sricharan, > > On 4/10/2017 7:21 AM, Sricharan R wrote: > >This is an equivalent to the DT's handling of the iommu master's probe > >with deferred probing when the corrsponding iommu is not probed yet. > >The lack of a registered IOMMU can be caused by the lack of a driver for > >the IOMMU, the IOMMU device probe not having been performed yet, having > >been deferred, or having failed. > > > >The first case occurs when the firmware describes the bus master and > >IOMMU topology correctly but no device driver exists for the IOMMU yet > >or the device driver has not been compiled in. Return NULL, the caller > >will configure the device without an IOMMU. > > > >The second and third cases are handled by deferring the probe of the bus > >master device which will eventually get reprobed after the IOMMU. > > > >The last case is currently handled by deferring the probe of the bus > >master device as well. A mechanism to either configure the bus master > >device without an IOMMU or to fail the bus master device probe depending > >on whether the IOMMU is optional or mandatory would be a good > >enhancement. > > > >Tested-by: Hanjun Guo > >Reviewed-by: Robin Murphy > >[Lorenzo: Added fixes for dma_coherent_mask overflow, acpi_dma_configure > > called multiple times for same device] > >Signed-off-by: Lorenzo Pieralisi > >Signed-off-by: Sricharan R > >--- > > drivers/acpi/arm64/iort.c | 33 ++++++++++++++++++++++++++++++++- > > drivers/acpi/scan.c | 11 ++++++++--- > > drivers/base/dma-mapping.c | 2 +- > > include/acpi/acpi_bus.h | 2 +- > > include/linux/acpi.h | 7 +++++-- > > 5 files changed, 47 insertions(+), 8 deletions(-) > > > >diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > >index 3dd9ec3..e323ece 100644 > >--- a/drivers/acpi/arm64/iort.c > >+++ b/drivers/acpi/arm64/iort.c > >@@ -543,6 +543,14 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev, > > const struct iommu_ops *ops = NULL; > > int ret = -ENODEV; > > struct fwnode_handle *iort_fwnode; > >+ struct iommu_fwspec *fwspec = dev->iommu_fwspec; > >+ > >+ /* > >+ * If we already translated the fwspec there > >+ * is nothing left to do, return the iommu_ops. > >+ */ > >+ if (fwspec && fwspec->ops) > >+ return fwspec->ops; > > Is this logic strictly required? It breaks masters with multiple SIDs > as only the first SID is actually added to the master's fwspec. My bad, that's indeed a silly bug I introduced. Please let me know if the patch below fixes it, we will send it upstream shortly. Lorenzo -- >8 -- diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c index c5fecf9..e326f2a 100644 --- a/drivers/acpi/arm64/iort.c +++ b/drivers/acpi/arm64/iort.c @@ -666,14 +666,6 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev, int ret = -ENODEV; struct fwnode_handle *iort_fwnode; - /* - * If we already translated the fwspec there - * is nothing left to do, return the iommu_ops. - */ - ops = iort_fwspec_iommu_ops(dev->iommu_fwspec); - if (ops) - return ops; - if (node) { iort_fwnode = iort_get_fwnode(node); if (!iort_fwnode) @@ -735,6 +727,14 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev) u32 streamid = 0; int err; + /* + * If we already translated the fwspec there + * is nothing left to do, return the iommu_ops. + */ + ops = iort_fwspec_iommu_ops(dev->iommu_fwspec); + if (ops) + return ops; + if (dev_is_pci(dev)) { struct pci_bus *bus = to_pci_dev(dev)->bus; u32 rid;