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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8A2FAC31E40 for ; Thu, 15 Aug 2019 12:09:12 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 57878206C2 for ; Thu, 15 Aug 2019 12:09:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 57878206C2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 1658610A0; Thu, 15 Aug 2019 12:09:12 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id EEC67FD8 for ; Thu, 15 Aug 2019 12:09:10 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 6020A711 for ; Thu, 15 Aug 2019 12:09:10 +0000 (UTC) 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 E31DF28; Thu, 15 Aug 2019 05:09:09 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 878C03F694; Thu, 15 Aug 2019 05:09:08 -0700 (PDT) Subject: Re: [PATCH 15/15] iommu/arm-smmu: Add context init implementation hook To: Will Deacon References: <6adbec8e4757f3b6c9f47135544a0302f8e7c55c.1565369764.git.robin.murphy@arm.com> <20190815105621.vt2gsuppjqgesrho@willie-the-truck> From: Robin Murphy Message-ID: <7acdf5fb-3516-efbb-7c8c-7f84c02faad7@arm.com> Date: Thu, 15 Aug 2019 13:09:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190815105621.vt2gsuppjqgesrho@willie-the-truck> Content-Language: en-GB Cc: bjorn.andersson@linaro.org, iommu@lists.linux-foundation.org, gregory.clement@bootlin.com, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On 15/08/2019 11:56, Will Deacon wrote: > On Fri, Aug 09, 2019 at 06:07:52PM +0100, Robin Murphy wrote: >> Allocating and initialising a context for a domain is another point >> where certain implementations are known to want special behaviour. >> Currently the other half of the Cavium workaround comes into play here, >> so let's finish the job to get the whole thing right out of the way. >> >> Signed-off-by: Robin Murphy >> --- >> drivers/iommu/arm-smmu-impl.c | 39 +++++++++++++++++++++++++-- >> drivers/iommu/arm-smmu.c | 51 +++++++---------------------------- >> drivers/iommu/arm-smmu.h | 42 +++++++++++++++++++++++++++-- >> 3 files changed, 86 insertions(+), 46 deletions(-) >> >> diff --git a/drivers/iommu/arm-smmu-impl.c b/drivers/iommu/arm-smmu-impl.c >> index c8904da08354..7a657d47b6ec 100644 >> --- a/drivers/iommu/arm-smmu-impl.c >> +++ b/drivers/iommu/arm-smmu-impl.c >> @@ -48,6 +48,12 @@ const struct arm_smmu_impl calxeda_impl = { >> }; >> >> >> +struct cavium_smmu { >> + struct arm_smmu_device smmu; >> + u32 id_base; >> +}; >> +#define to_csmmu(s) container_of(s, struct cavium_smmu, smmu) > > To be honest with you, I'd just use container_of directly for the two > callsites that need it. "to_csmmu" isn't a great name when we're also got > the calxeda thing in here. Sure, by this point I was mostly just going for completeness in terms of sketching out an example for subclassing arm_smmu_device. The Tegra patches will now serve as a more complete example anyway, so indeed we can live without it here. >> static int cavium_cfg_probe(struct arm_smmu_device *smmu) >> { >> static atomic_t context_count = ATOMIC_INIT(0); >> @@ -56,17 +62,46 @@ static int cavium_cfg_probe(struct arm_smmu_device *smmu) >> * Ensure ASID and VMID allocation is unique across all SMMUs in >> * the system. >> */ >> - smmu->cavium_id_base = atomic_fetch_add(smmu->num_context_banks, >> + to_csmmu(smmu)->id_base = atomic_fetch_add(smmu->num_context_banks, >> &context_count); >> dev_notice(smmu->dev, "\tenabling workaround for Cavium erratum 27704\n"); >> >> return 0; >> } >> >> +int cavium_init_context(struct arm_smmu_domain *smmu_domain) >> +{ >> + u32 id_base = to_csmmu(smmu_domain->smmu)->id_base; >> + >> + if (smmu_domain->stage == ARM_SMMU_DOMAIN_S2) >> + smmu_domain->cfg.vmid += id_base; >> + else >> + smmu_domain->cfg.asid += id_base; >> + >> + return 0; >> +} >> + >> const struct arm_smmu_impl cavium_impl = { >> .cfg_probe = cavium_cfg_probe, >> + .init_context = cavium_init_context, >> }; >> >> +struct arm_smmu_device *cavium_smmu_impl_init(struct arm_smmu_device *smmu) >> +{ >> + struct cavium_smmu *csmmu; >> + >> + csmmu = devm_kzalloc(smmu->dev, sizeof(*csmmu), GFP_KERNEL); >> + if (!csmmu) >> + return ERR_PTR(-ENOMEM); >> + >> + csmmu->smmu = *smmu; >> + csmmu->smmu.impl = &cavium_impl; >> + >> + devm_kfree(smmu->dev, smmu); >> + >> + return &csmmu->smmu; >> +} >> + >> >> #define ARM_MMU500_ACTLR_CPRE (1 << 1) >> >> @@ -121,7 +156,7 @@ struct arm_smmu_device *arm_smmu_impl_init(struct arm_smmu_device *smmu) >> smmu->impl = &calxeda_impl; >> >> if (smmu->model == CAVIUM_SMMUV2) >> - smmu->impl = &cavium_impl; >> + return cavium_smmu_impl_init(smmu); >> >> if (smmu->model == ARM_MMU500) >> smmu->impl = &arm_mmu500_impl; > > Maybe rework this so we do the calxeda detection first (and return if we > match), followed by a switch on smmu->model to make it crystal clear that > we match only one? As I see it, "match only one" is really only a short-term thing, though, so I didn't want to get *too* hung up on it. Ultimately we're going to have cases where we need to combine e.g. MMU-500 implementation quirks with platform integration quirks - I've been mostly planning on coming back to think about that (and potentially rework this whole logic) later, but I guess it wouldn't hurt to plan out a bit more structure from the start. I'll have a hack on that (and all the other comments) today and hopefully have a v2 by tomorrow. Robin. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu