From patchwork Tue May 19 17:54:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Philippe Brucker X-Patchwork-Id: 200353 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=-9.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 55F6BC433E5 for ; Tue, 19 May 2020 18:01:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D767207D3 for ; Tue, 19 May 2020 18:01:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="LrVLTpbG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727009AbgESSBr (ORCPT ); Tue, 19 May 2020 14:01:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727045AbgESSBq (ORCPT ); Tue, 19 May 2020 14:01:46 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F377C08C5C0 for ; Tue, 19 May 2020 11:01:45 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id l11so447735wru.0 for ; Tue, 19 May 2020 11:01:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=2PFJF5btJNBPprEd/LjKgNayT4ugYCOJnPARFwzNang=; b=LrVLTpbGU4NiphecFL5M4ouOgZufinFzBCfZAELELYApdrOCEHujSXy+FUdD42qX8l 8vjiQkUpQllNaT36Vs+gVTDsK0mCFuQ4hQ5Y5M23lUpiTU6YsaHYDzi9lNFE4T8WHXeb NZrBW40uyUB/AajvgtfXJEDwUayE2sLlUwgHNn+HnsB/dijnotLjnkjd83m8g012WOOf rdixreNwYbkTse3eCKAZLtShfMQ+jSekNlwF9YLtQB6Hkp2JTm1Q0bhjWGXr1Y9Fvbez rfin57fhrSJY8eRT3Rr+KPlNcOf+8a2Yn81ZFbRYIooZJe/UEU5y2m5zLbjU+BdEftqx g0yw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=2PFJF5btJNBPprEd/LjKgNayT4ugYCOJnPARFwzNang=; b=QCUvcGDqUWCx21TJV1jZFqvjl2zNI/YSgeCrG9rTVWkOdT/UsQqPjFJX8Zx4JLJAt4 IXQLUAFtFqkL8J5U8JYH8w9jvPDLghfQmf70wqf4Xmm4CNSPQmuKAhs9ZvHgoSRkb1M7 CEugqBkEhFxair7pUH/b2mO4CPD//NadIVmbDAQ9VoGIzqxr7PmLb3kKQeK672mQCfJG F6ym+KcPlCOZfX0e9u37HOB3NJmavMuxZVTVkbDRBk7kvgRLy4J8COR8pM10W3J8Vecg /9TzTd48Q1dvM4aDKELtFGnKrlTPRMWQxCoaczsNGNYD4wMos0TtNrWwy2u21e39qOSH 1wbw== X-Gm-Message-State: AOAM5304l44q26nSW3KL2I4fC/3Hy9NPy2YLzZ3tDZeiPtfmJTlti8gI ZvFCi+V3KQ/m0Ug5Jvzd/7K86Q== X-Google-Smtp-Source: ABdhPJztpovo6qlRG1M54wjBp9zTXl5RwTuJ1SnYrJPYt/7mMDTUOS9LfLeUBDTtOc3yWZxPnijhIQ== X-Received: by 2002:a5d:5048:: with SMTP id h8mr76396wrt.293.1589911303946; Tue, 19 May 2020 11:01:43 -0700 (PDT) Received: from localhost.localdomain ([2001:171b:226e:c200:c43b:ef78:d083:b355]) by smtp.gmail.com with ESMTPSA id 1sm510496wmz.13.2020.05.19.11.01.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 May 2020 11:01:43 -0700 (PDT) From: Jean-Philippe Brucker To: iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, linux-mm@kvack.org Cc: joro@8bytes.org, catalin.marinas@arm.com, will@kernel.org, robin.murphy@arm.com, kevin.tian@intel.com, baolu.lu@linux.intel.com, Jonathan.Cameron@huawei.com, jacob.jun.pan@linux.intel.com, christian.koenig@amd.com, felix.kuehling@amd.com, zhangfei.gao@linaro.org, jgg@ziepe.ca, xuzaibo@huawei.com, fenghua.yu@intel.com, hch@infradead.org, Jean-Philippe Brucker Subject: [PATCH v7 02/24] iommu/ioasid: Add ioasid references Date: Tue, 19 May 2020 19:54:40 +0200 Message-Id: <20200519175502.2504091-3-jean-philippe@linaro.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200519175502.2504091-1-jean-philippe@linaro.org> References: <20200519175502.2504091-1-jean-philippe@linaro.org> MIME-Version: 1.0 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Let IOASID users take references to existing ioasids with ioasid_get(). ioasid_put() drops a reference and only frees the ioasid when its reference number is zero. It returns true if the ioasid was freed. For drivers that don't call ioasid_get(), ioasid_put() is the same as ioasid_free(). Signed-off-by: Jean-Philippe Brucker --- v6->v7: rename ioasid_free() to ioasid_put(), add WARN in ioasid_get() --- include/linux/ioasid.h | 10 ++++++++-- drivers/iommu/intel-iommu.c | 4 ++-- drivers/iommu/intel-svm.c | 6 +++--- drivers/iommu/ioasid.c | 38 +++++++++++++++++++++++++++++++++---- 4 files changed, 47 insertions(+), 11 deletions(-) diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h index 6f000d7a0ddc..e9dacd4b9f6b 100644 --- a/include/linux/ioasid.h +++ b/include/linux/ioasid.h @@ -34,7 +34,8 @@ struct ioasid_allocator_ops { #if IS_ENABLED(CONFIG_IOASID) ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, void *private); -void ioasid_free(ioasid_t ioasid); +void ioasid_get(ioasid_t ioasid); +bool ioasid_put(ioasid_t ioasid); void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid, bool (*getter)(void *)); int ioasid_register_allocator(struct ioasid_allocator_ops *allocator); @@ -48,10 +49,15 @@ static inline ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, return INVALID_IOASID; } -static inline void ioasid_free(ioasid_t ioasid) +static inline void ioasid_get(ioasid_t ioasid) { } +static inline bool ioasid_put(ioasid_t ioasid) +{ + return false; +} + static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid, bool (*getter)(void *)) { diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index ed21ce6d1238..0230f35480ee 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -5432,7 +5432,7 @@ static void auxiliary_unlink_device(struct dmar_domain *domain, domain->auxd_refcnt--; if (!domain->auxd_refcnt && domain->default_pasid > 0) - ioasid_free(domain->default_pasid); + ioasid_put(domain->default_pasid); } static int aux_domain_add_dev(struct dmar_domain *domain, @@ -5494,7 +5494,7 @@ static int aux_domain_add_dev(struct dmar_domain *domain, spin_unlock(&iommu->lock); spin_unlock_irqrestore(&device_domain_lock, flags); if (!domain->auxd_refcnt && domain->default_pasid > 0) - ioasid_free(domain->default_pasid); + ioasid_put(domain->default_pasid); return ret; } diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index 2998418f0a38..86f1264bd07c 100644 --- a/drivers/iommu/intel-svm.c +++ b/drivers/iommu/intel-svm.c @@ -353,7 +353,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ if (mm) { ret = mmu_notifier_register(&svm->notifier, mm); if (ret) { - ioasid_free(svm->pasid); + ioasid_put(svm->pasid); kfree(svm); kfree(sdev); goto out; @@ -371,7 +371,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ if (ret) { if (mm) mmu_notifier_unregister(&svm->notifier, mm); - ioasid_free(svm->pasid); + ioasid_put(svm->pasid); kfree(svm); kfree(sdev); goto out; @@ -447,7 +447,7 @@ int intel_svm_unbind_mm(struct device *dev, int pasid) kfree_rcu(sdev, rcu); if (list_empty(&svm->devs)) { - ioasid_free(svm->pasid); + ioasid_put(svm->pasid); if (svm->mm) mmu_notifier_unregister(&svm->notifier, svm->mm); list_del(&svm->list); diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c index 0f8dd377aada..50ee27bbd04e 100644 --- a/drivers/iommu/ioasid.c +++ b/drivers/iommu/ioasid.c @@ -2,7 +2,7 @@ /* * I/O Address Space ID allocator. There is one global IOASID space, split into * subsets. Users create a subset with DECLARE_IOASID_SET, then allocate and - * free IOASIDs with ioasid_alloc and ioasid_free. + * free IOASIDs with ioasid_alloc and ioasid_put. */ #include #include @@ -15,6 +15,7 @@ struct ioasid_data { struct ioasid_set *set; void *private; struct rcu_head rcu; + refcount_t refs; }; /* @@ -314,6 +315,7 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, data->set = set; data->private = private; + refcount_set(&data->refs, 1); /* * Custom allocator needs allocator data to perform platform specific @@ -346,11 +348,34 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, EXPORT_SYMBOL_GPL(ioasid_alloc); /** - * ioasid_free - Free an IOASID + * ioasid_get - obtain a reference to the IOASID + */ +void ioasid_get(ioasid_t ioasid) +{ + struct ioasid_data *ioasid_data; + + spin_lock(&ioasid_allocator_lock); + ioasid_data = xa_load(&active_allocator->xa, ioasid); + if (ioasid_data) + refcount_inc(&ioasid_data->refs); + else + WARN_ON(1); + spin_unlock(&ioasid_allocator_lock); +} +EXPORT_SYMBOL_GPL(ioasid_get); + +/** + * ioasid_put - Release a reference to an ioasid * @ioasid: the ID to remove + * + * Put a reference to the IOASID, free it when the number of references drops to + * zero. + * + * Return: %true if the IOASID was freed, %false otherwise. */ -void ioasid_free(ioasid_t ioasid) +bool ioasid_put(ioasid_t ioasid) { + bool free = false; struct ioasid_data *ioasid_data; spin_lock(&ioasid_allocator_lock); @@ -360,6 +385,10 @@ void ioasid_free(ioasid_t ioasid) goto exit_unlock; } + free = refcount_dec_and_test(&ioasid_data->refs); + if (!free) + goto exit_unlock; + active_allocator->ops->free(ioasid, active_allocator->ops->pdata); /* Custom allocator needs additional steps to free the xa element */ if (active_allocator->flags & IOASID_ALLOCATOR_CUSTOM) { @@ -369,8 +398,9 @@ void ioasid_free(ioasid_t ioasid) exit_unlock: spin_unlock(&ioasid_allocator_lock); + return free; } -EXPORT_SYMBOL_GPL(ioasid_free); +EXPORT_SYMBOL_GPL(ioasid_put); /** * ioasid_find - Find IOASID data