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=-15.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 D2EBEC2B9F4 for ; Mon, 14 Jun 2021 17:19:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF9B8611C0 for ; Mon, 14 Jun 2021 17:19:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235614AbhFNRVk (ORCPT ); Mon, 14 Jun 2021 13:21:40 -0400 Received: from foss.arm.com ([217.140.110.172]:42092 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234137AbhFNRVj (ORCPT ); Mon, 14 Jun 2021 13:21:39 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8101F11D4; Mon, 14 Jun 2021 10:19:36 -0700 (PDT) Received: from [10.57.9.136] (unknown [10.57.9.136]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 07B363F70D; Mon, 14 Jun 2021 10:19:34 -0700 (PDT) Subject: Re: [PATCH v12 5/5] iommu: Remove mode argument from iommu_set_dma_strict() To: John Garry , joro@8bytes.org, will@kernel.org, dwmw2@infradead.org, baolu.lu@linux.intel.com Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linuxarm@huawei.com, thunder.leizhen@huawei.com, chenxiang66@hisilicon.com References: <1623414043-40745-1-git-send-email-john.garry@huawei.com> <1623414043-40745-6-git-send-email-john.garry@huawei.com> <868374d4-e816-b607-82de-7e7c27a4c66b@arm.com> From: Robin Murphy Message-ID: <56f1fc88-baec-e1cf-109e-59978e2d16a8@arm.com> Date: Mon, 14 Jun 2021 18:19:29 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021-06-14 18:03, John Garry wrote: > On 14/06/2021 17:25, Robin Murphy wrote: >> On 2021-06-11 13:20, John Garry wrote: >>> We only ever now set strict mode enabled in iommu_set_dma_strict(), so >>> just remove the argument. >>> >>> Signed-off-by: John Garry >>> --- >>>   drivers/iommu/amd/init.c    | 2 +- >>>   drivers/iommu/intel/iommu.c | 6 +++--- >>>   drivers/iommu/iommu.c       | 5 ++--- >>>   include/linux/iommu.h       | 2 +- >>>   4 files changed, 7 insertions(+), 8 deletions(-) >>> >>> diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c >>> index 0e6ae6d68f14..27e9677ec303 100644 >>> --- a/drivers/iommu/amd/init.c >>> +++ b/drivers/iommu/amd/init.c >>> @@ -3098,7 +3098,7 @@ static int __init parse_amd_iommu_options(char >>> *str) >>>   { >>>       for (; *str; ++str) { >>>           if (strncmp(str, "fullflush", 9) == 0) >>> -            iommu_set_dma_strict(true); >>> +            iommu_set_dma_strict(); >>>           if (strncmp(str, "force_enable", 12) == 0) >>>               amd_iommu_force_enable = true; >>>           if (strncmp(str, "off", 3) == 0) >>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c >>> index 6763e516362c..e77b8b6e7838 100644 >>> --- a/drivers/iommu/intel/iommu.c >>> +++ b/drivers/iommu/intel/iommu.c >>> @@ -452,7 +452,7 @@ static int __init intel_iommu_setup(char *str) >>>               pr_warn("intel_iommu=forcedac deprecated; use >>> iommu.forcedac instead\n"); >>>               iommu_dma_forcedac = true; >>>           } else if (!strncmp(str, "strict", 6)) { >>> -            iommu_set_dma_strict(true); >>> +            iommu_set_dma_strict(); >>>           } else if (!strncmp(str, "sp_off", 6)) { >>>               pr_info("Disable supported super page\n"); >>>               intel_iommu_superpage = 0; >>> @@ -4392,7 +4392,7 @@ int __init intel_iommu_init(void) >>>            */ >>>           if (cap_caching_mode(iommu->cap)) { >>>               pr_warn("IOMMU batching disallowed due to >>> virtualization\n"); >>> -            iommu_set_dma_strict(true); >>> +            iommu_set_dma_strict(); >>>           } >>>           iommu_device_sysfs_add(&iommu->iommu, NULL, >>>                          intel_iommu_groups, >>> @@ -5663,7 +5663,7 @@ static void quirk_calpella_no_shadow_gtt(struct >>> pci_dev *dev) >>>       } else if (dmar_map_gfx) { >>>           /* we have to ensure the gfx device is idle before we flush */ >>>           pci_info(dev, "Disabling batched IOTLB flush on Ironlake\n"); >>> -        iommu_set_dma_strict(true); >>> +        iommu_set_dma_strict(); >>>       } >>>   } >>>   DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x0040, >>> quirk_calpella_no_shadow_gtt); >>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >>> index ccbd5d4c1a50..146cb71c7441 100644 >>> --- a/drivers/iommu/iommu.c >>> +++ b/drivers/iommu/iommu.c >>> @@ -350,10 +350,9 @@ static int __init iommu_dma_setup(char *str) >>>   } >>>   early_param("iommu.strict", iommu_dma_setup); >>> -void iommu_set_dma_strict(bool strict) >>> +void iommu_set_dma_strict(void) >>>   { >>> -    if (strict || !(iommu_cmd_line & IOMMU_CMD_LINE_STRICT)) >> >> We shouldn't need to keep IOMMU_CMD_LINE_STRICT at all now, since it >> was only to prevent a driver's "default lazy" setting passed in here >> from downgrading an explicitly-set strict mode. >> >> With that cleaned up too, >> > > Patch 1/5 mentions whether the invalidation policy comes from the > cmdline - similar to the default domain type print - so I was going to > keep that. Oh, silly me, I'd forgotten that already and was just looking at my local tree... Let's keep it for consistency with how we report the domain type then. > And then maybe we should also set it from the deprecated x86 > driver-specific params. I don't think it's worth exporting more low-level guts to allow that to happen - tying in to iommu_set_dma_strict() would be too late, as before. I think the separate pr_warn()s which announce the relevant parameter is deprecated (but has still taken effect) should be enough. Cheers, Robin.