From patchwork Thu Jun 18 15:51:15 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: 11612703 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 27A5214E3 for ; Thu, 18 Jun 2020 15:52:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DB1E6208B3 for ; Thu, 18 Jun 2020 15:52:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Eds4e2o9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB1E6208B3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 090678D0030; Thu, 18 Jun 2020 11:52:43 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 068858D0018; Thu, 18 Jun 2020 11:52:42 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E73A48D0030; Thu, 18 Jun 2020 11:52:42 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0142.hostedemail.com [216.40.44.142]) by kanga.kvack.org (Postfix) with ESMTP id D1B968D0018 for ; Thu, 18 Jun 2020 11:52:42 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 933281272BC for ; Thu, 18 Jun 2020 15:52:42 +0000 (UTC) X-FDA: 76942775364.02.face86_0a0ae6926e11 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id 6AB9C100B38 for ; Thu, 18 Jun 2020 15:52:42 +0000 (UTC) X-Spam-Summary: 2,0,0,fad5f8b54845fa7d,d41d8cd98f00b204,jean-philippe@linaro.org,,RULES_HIT:2:41:355:379:541:800:960:966:968:973:988:989:1260:1311:1314:1345:1359:1437:1515:1535:1605:1730:1747:1777:1792:2196:2199:2393:2559:2562:3138:3139:3140:3141:3142:3865:3866:3867:3868:3871:3872:3874:4049:4120:4250:4321:4385:4605:5007:6261:6653:6742:7875:8660:9010:9167:10004:11026:11473:11658:11914:12043:12291:12296:12297:12438:12517:12519:12555:12683:12895:13148:13230:13894:13972:14096:14394:21080:21324:21444:21451:21627:21939:21987:21990:30003:30034:30054:30055:30056:30080,0,RBL:209.85.218.65:@linaro.org:.lbl8.mailshell.net-62.2.0.100 66.100.201.201,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:ft,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:26,LUA_SUMMARY:none X-HE-Tag: face86_0a0ae6926e11 X-Filterd-Recvd-Size: 9454 Received: from mail-ej1-f65.google.com (mail-ej1-f65.google.com [209.85.218.65]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Thu, 18 Jun 2020 15:52:41 +0000 (UTC) Received: by mail-ej1-f65.google.com with SMTP id n24so6972492ejd.0 for ; Thu, 18 Jun 2020 08:52:41 -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=gANJ9nXJh01yt9NJy6mJRUbndSE80vIrxk0QteKIq3c=; b=Eds4e2o9/aTlytifgQchMEkJmVJnHukU0ovaep4b99cT1h6zth+zUqp366TT6K7ePX HiZEqi5WIama9YvlIAens9d1oSuRcu30EdLiupH19lT8Hmm2muD9gKIAMgXLTT8oZzjY MoyoHHPnrcr8cOojysoVY47yfdgPaVRYmZmo+khdV4Ej00BOefC8o/w6f/PYTJyS6JMS IE97PCTm2L9rvU65hRt0iESOfgfc1BzLFCJZHQEDWvQTL3BUfPf06ylKZClOTGVvHCHR HxJDIw/+s/Qhsbwm5tathG8DD43vy8bx/z/kb1lxFBK35YaCkkejan7zgAl8K15t3TWZ HQ7w== 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=gANJ9nXJh01yt9NJy6mJRUbndSE80vIrxk0QteKIq3c=; b=q5rdE4Nkhn4Jmv7Y1gPHq3IHS5IR3/Mdm/Celxk2/ZF/bPX3gGVXFjgTjFU7RlDHpQ 1SbjfEFvCb/mbm3syUhNfF+S7o0pPnJaKlIvsty7dVRdhl9F1HPFWWSm2WQPHHNyjq9q IuokpIJQqsp8wuHBhaGJezbCCTUmTn7EfmwOcHtWBNb+BPKUH52HBzhPXUmnr+NAhdrM hu9Tn00gZtLSI6mtnA8tJH1Kh9TUqVuNsMMwHQ16sE+7SwN43twkDl3QbJ5m4+NnlI7W qtCxvCI8+uJlFFZAG8KlKrm1O0X85mqyguIwpNKb2Ep4aZe/7iP0u1DpyQk7pP/uhuiK j1KA== X-Gm-Message-State: AOAM532p9TUqZh8LgJIktFoPSNUpVBVDas6p3nRBMAZC9ddBY+oJeIBd opafJh5lRqiOVPrRk3XJqGVlEA== X-Google-Smtp-Source: ABdhPJwyzOwFmlJDohdbHbSJOb408dno2oi+63HZld2Ti01+pRXVJHbN4UECF6xp5+TKBsOTjUOPvw== X-Received: by 2002:a17:906:68c5:: with SMTP id y5mr4450793ejr.436.1592495560894; Thu, 18 Jun 2020 08:52:40 -0700 (PDT) Received: from localhost.localdomain ([2001:1715:4e26:a7e0:116c:c27a:3e7f:5eaf]) by smtp.gmail.com with ESMTPSA id 63sm2402267edy.8.2020.06.18.08.52.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Jun 2020 08:52:40 -0700 (PDT) From: Jean-Philippe Brucker To: iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Cc: joro@8bytes.org, catalin.marinas@arm.com, will@kernel.org, robin.murphy@arm.com, baolu.lu@linux.intel.com, Jonathan.Cameron@huawei.com, jacob.jun.pan@linux.intel.com, zhangfei.gao@linaro.org, xuzaibo@huawei.com, zhengxiang9@huawei.com, fenghua.yu@intel.com, hch@infradead.org, Jean-Philippe Brucker Subject: [PATCH v8 02/12] iommu/ioasid: Add ioasid references Date: Thu, 18 Jun 2020 17:51:15 +0200 Message-Id: <20200618155125.1548969-3-jean-philippe@linaro.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200618155125.1548969-1-jean-philippe@linaro.org> References: <20200618155125.1548969-1-jean-philippe@linaro.org> MIME-Version: 1.0 X-Rspamd-Queue-Id: 6AB9C100B38 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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(). Reviewed-by: Lu Baolu Signed-off-by: Jean-Philippe Brucker --- 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 6f000d7a0ddcd..e9dacd4b9f6bb 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 9129663a7406b..a5840b8ef14b7 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -5131,7 +5131,7 @@ 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, @@ -5193,7 +5193,7 @@ 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 6c87c807a0abb..b078a697c42e8 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -546,7 +546,7 @@ intel_svm_bind_mm(struct device *dev, int flags, struct svm_dev_ops *ops, 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; @@ -564,7 +564,7 @@ intel_svm_bind_mm(struct device *dev, int flags, struct svm_dev_ops *ops, if (ret) { if (mm) mmu_notifier_unregister(&svm->notifier, mm); - ioasid_free(svm->pasid); + ioasid_put(svm->pasid); kfree(svm); kfree(sdev); goto out; @@ -639,7 +639,7 @@ static 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 0f8dd377aada3..50ee27bbd04ec 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