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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6085C433EF for ; Tue, 21 Jun 2022 14:49:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351992AbiFUOs7 (ORCPT ); Tue, 21 Jun 2022 10:48:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351922AbiFUOsd (ORCPT ); Tue, 21 Jun 2022 10:48:33 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3540B175AD for ; Tue, 21 Jun 2022 07:48:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655822912; x=1687358912; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=23hC2f4dgyTyX4xCupRfbmP4pCP+etJyCkXoUnCA06c=; b=R+TbAYfw8ewkSg7/1lArpPJAnmOBWpm5mraDm3jZSUXYBFa+aFVynnG4 JP5pQrdOBjKlRhrfgQ0XcAU9OtSqs7K5Tbt2nveh3Pq109g+P4y56J/M9 N+SL4UzQU0jOP3+slwx+T4fOqjh7EtTapq6dODDi6FCvMf4WutM8XE8jY gGQxxVrO69sQRTkF6xcSVcEoBpv5MdSpKb9aDDeLSKq+pNLURFfEuctZS Onq8Tl56B/yziN/3+4byzY3D6CeJuJCK+/I/8+grvMleuFk6AR1ftjAwe GmEf77cG+T9k28REqd+E/rQ6QQYefWqlrcxw+OeJkOPxs5l/8UrxmRT6Z w==; X-IronPort-AV: E=McAfee;i="6400,9594,10384"; a="260566691" X-IronPort-AV: E=Sophos;i="5.92,209,1650956400"; d="scan'208";a="260566691" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jun 2022 07:48:32 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,209,1650956400"; d="scan'208";a="643659433" Received: from allen-box.sh.intel.com ([10.239.159.48]) by fmsmga008.fm.intel.com with ESMTP; 21 Jun 2022 07:48:28 -0700 From: Lu Baolu To: Joerg Roedel , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Jean-Philippe Brucker , Dave Jiang , Vinod Koul Cc: Eric Auger , Liu Yi L , Jacob jun Pan , iommu@lists.linux-foundation.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v9 07/11] iommu/sva: Refactoring iommu_sva_bind/unbind_device() Date: Tue, 21 Jun 2022 22:43:49 +0800 Message-Id: <20220621144353.17547-8-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220621144353.17547-1-baolu.lu@linux.intel.com> References: <20220621144353.17547-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The existing iommu SVA interfaces are implemented by calling the SVA specific iommu ops provided by the IOMMU drivers. There's no need for any SVA specific ops in iommu_ops vector anymore as we can achieve this through the generic attach/detach_dev_pasid domain ops. This refactors the IOMMU SVA interfaces implementation by using the set/block_pasid_dev ops and align them with the concept of the SVA iommu domain. Put the new SVA code in the sva related file in order to make it self-contained. Signed-off-by: Lu Baolu --- include/linux/iommu.h | 67 +++++++++++-------- drivers/iommu/iommu-sva-lib.c | 98 ++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 119 ++++++++-------------------------- 3 files changed, 165 insertions(+), 119 deletions(-) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index b8b6b8c5e20e..c0c23d9fd8fe 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -39,7 +39,6 @@ struct device; struct iommu_domain; struct iommu_domain_ops; struct notifier_block; -struct iommu_sva; struct iommu_fault_event; struct iommu_dma_cookie; @@ -57,6 +56,14 @@ struct iommu_domain_geometry { bool force_aperture; /* DMA only allowed in mappable range? */ }; +/** + * struct iommu_sva - handle to a device-mm bond + */ +struct iommu_sva { + struct device *dev; + refcount_t users; +}; + /* Domain feature flags */ #define __IOMMU_DOMAIN_PAGING (1U << 0) /* Support for iommu_map/unmap */ #define __IOMMU_DOMAIN_DMA_API (1U << 1) /* Domain for use in DMA-API @@ -105,6 +112,7 @@ struct iommu_domain { }; struct { /* IOMMU_DOMAIN_SVA */ struct mm_struct *mm; + struct iommu_sva bond; }; }; }; @@ -638,13 +646,6 @@ struct iommu_fwspec { /* ATS is supported */ #define IOMMU_FWSPEC_PCI_RC_ATS (1 << 0) -/** - * struct iommu_sva - handle to a device-mm bond - */ -struct iommu_sva { - struct device *dev; -}; - int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode, const struct iommu_ops *ops); void iommu_fwspec_free(struct device *dev); @@ -685,11 +686,6 @@ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f); int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f); bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f); -struct iommu_sva *iommu_sva_bind_device(struct device *dev, - struct mm_struct *mm); -void iommu_sva_unbind_device(struct iommu_sva *handle); -u32 iommu_sva_get_pasid(struct iommu_sva *handle); - int iommu_device_use_default_domain(struct device *dev); void iommu_device_unuse_default_domain(struct device *dev); @@ -703,6 +699,8 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid); #else /* CONFIG_IOMMU_API */ struct iommu_ops {}; @@ -1033,21 +1031,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) return -ENODEV; } -static inline struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) -{ - return NULL; -} - -static inline void iommu_sva_unbind_device(struct iommu_sva *handle) -{ -} - -static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - return IOMMU_PASID_INVALID; -} - static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev) { return NULL; @@ -1093,6 +1076,12 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid) { } + +static inline struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid) +{ + return NULL; +} #endif /* CONFIG_IOMMU_API */ /** @@ -1118,4 +1107,26 @@ void iommu_debugfs_setup(void); static inline void iommu_debugfs_setup(void) {} #endif +#ifdef CONFIG_IOMMU_SVA +struct iommu_sva *iommu_sva_bind_device(struct device *dev, + struct mm_struct *mm); +void iommu_sva_unbind_device(struct iommu_sva *handle); +u32 iommu_sva_get_pasid(struct iommu_sva *handle); +#else +static inline struct iommu_sva * +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) +{ + return NULL; +} + +static inline void iommu_sva_unbind_device(struct iommu_sva *handle) +{ +} + +static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + return IOMMU_PASID_INVALID; +} +#endif /* CONFIG_IOMMU_SVA */ + #endif /* __LINUX_IOMMU_H */ diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c index 106506143896..1e3e2b395b1e 100644 --- a/drivers/iommu/iommu-sva-lib.c +++ b/drivers/iommu/iommu-sva-lib.c @@ -4,6 +4,7 @@ */ #include #include +#include #include "iommu-sva-lib.h" @@ -69,3 +70,100 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid) return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero); } EXPORT_SYMBOL_GPL(iommu_sva_find); + +/** + * iommu_sva_bind_device() - Bind a process address space to a device + * @dev: the device + * @mm: the mm to bind, caller must hold a reference to mm_users + * + * Create a bond between device and address space, allowing the device to access + * the mm using the returned PASID. If a bond already exists between @device and + * @mm, it is returned and an additional reference is taken. Caller must call + * iommu_sva_unbind_device() to release each reference. + * + * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to + * initialize the required SVA features. + * + * On error, returns an ERR_PTR value. + */ +struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) +{ + struct iommu_domain *domain; + ioasid_t max_pasids; + int ret = -EINVAL; + + /* Allocate mm->pasid if necessary. */ + max_pasids = dev->iommu->max_pasids; + if (!max_pasids) + return ERR_PTR(-EOPNOTSUPP); + + ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1); + if (ret) + return ERR_PTR(ret); + + mutex_lock(&iommu_sva_lock); + /* Search for an existing domain. */ + domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid); + if (domain) { + refcount_inc(&domain->bond.users); + goto out_success; + } + + /* Allocate a new domain and set it on device pasid. */ + domain = iommu_sva_domain_alloc(dev, mm); + if (!domain) { + ret = -ENOMEM; + goto out_unlock; + } + + ret = iommu_attach_device_pasid(domain, dev, mm->pasid); + if (ret) + goto out_free_domain; + domain->bond.dev = dev; + refcount_set(&domain->bond.users, 1); + +out_success: + mutex_unlock(&iommu_sva_lock); + return &domain->bond; + +out_free_domain: + iommu_domain_free(domain); +out_unlock: + mutex_unlock(&iommu_sva_lock); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(iommu_sva_bind_device); + +/** + * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device + * @handle: the handle returned by iommu_sva_bind_device() + * + * Put reference to a bond between device and address space. The device should + * not be issuing any more transaction for this PASID. All outstanding page + * requests for this PASID must have been flushed to the IOMMU. + */ +void iommu_sva_unbind_device(struct iommu_sva *handle) +{ + struct device *dev = handle->dev; + struct iommu_domain *domain = + container_of(handle, struct iommu_domain, bond); + ioasid_t pasid = iommu_sva_get_pasid(handle); + + mutex_lock(&iommu_sva_lock); + if (refcount_dec_and_test(&domain->bond.users)) { + iommu_detach_device_pasid(domain, dev, pasid); + iommu_domain_free(domain); + } + mutex_unlock(&iommu_sva_lock); +} +EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); + +u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + struct iommu_domain *domain = + container_of(handle, struct iommu_domain, bond); + + return domain->mm->pasid; +} +EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 8450f914cb2b..34d71418e7c7 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2789,97 +2789,6 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat) } EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled); -/** - * iommu_sva_bind_device() - Bind a process address space to a device - * @dev: the device - * @mm: the mm to bind, caller must hold a reference to it - * - * Create a bond between device and address space, allowing the device to access - * the mm using the returned PASID. If a bond already exists between @device and - * @mm, it is returned and an additional reference is taken. Caller must call - * iommu_sva_unbind_device() to release each reference. - * - * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to - * initialize the required SVA features. - * - * On error, returns an ERR_PTR value. - */ -struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) -{ - struct iommu_group *group; - struct iommu_sva *handle = ERR_PTR(-EINVAL); - const struct iommu_ops *ops = dev_iommu_ops(dev); - - if (!ops->sva_bind) - return ERR_PTR(-ENODEV); - - group = iommu_group_get(dev); - if (!group) - return ERR_PTR(-ENODEV); - - /* Ensure device count and domain don't change while we're binding */ - mutex_lock(&group->mutex); - - /* - * To keep things simple, SVA currently doesn't support IOMMU groups - * with more than one device. Existing SVA-capable systems are not - * affected by the problems that required IOMMU groups (lack of ACS - * isolation, device ID aliasing and other hardware issues). - */ - if (iommu_group_device_count(group) != 1) - goto out_unlock; - - handle = ops->sva_bind(dev, mm); - -out_unlock: - mutex_unlock(&group->mutex); - iommu_group_put(group); - - return handle; -} -EXPORT_SYMBOL_GPL(iommu_sva_bind_device); - -/** - * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device - * @handle: the handle returned by iommu_sva_bind_device() - * - * Put reference to a bond between device and address space. The device should - * not be issuing any more transaction for this PASID. All outstanding page - * requests for this PASID must have been flushed to the IOMMU. - */ -void iommu_sva_unbind_device(struct iommu_sva *handle) -{ - struct iommu_group *group; - struct device *dev = handle->dev; - const struct iommu_ops *ops = dev_iommu_ops(dev); - - if (!ops->sva_unbind) - return; - - group = iommu_group_get(dev); - if (!group) - return; - - mutex_lock(&group->mutex); - ops->sva_unbind(handle); - mutex_unlock(&group->mutex); - - iommu_group_put(group); -} -EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); - -u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - const struct iommu_ops *ops = dev_iommu_ops(handle->dev); - - if (!ops->sva_get_pasid) - return IOMMU_PASID_INVALID; - - return ops->sva_get_pasid(handle); -} -EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); - /* * Changes the default domain of an iommu group that has *only* one device * @@ -3364,3 +3273,31 @@ void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, iommu_group_put(group); } + +/* + * This is a variant of iommu_get_domain_for_dev(). It returns the existing + * domain attached to pasid of a device. It's only for internal use of the + * IOMMU subsystem. The caller must take care to avoid any possible + * use-after-free case. + */ +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid) +{ + struct iommu_domain *domain; + struct iommu_group *group; + + if (!pasid_valid(pasid)) + return NULL; + + group = iommu_group_get(dev); + if (!group) + return NULL; + /* + * The xarray protects its internal state with RCU. Hence the domain + * obtained is either NULL or fully formed. + */ + domain = xa_load(&group->pasid_array, pasid); + iommu_group_put(group); + + return domain; +} -- 2.25.1 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 Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9CAC3C43334 for ; Tue, 21 Jun 2022 14:48:36 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 4519D60EB3; Tue, 21 Jun 2022 14:48:36 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 4519D60EB3 Authentication-Results: smtp3.osuosl.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=R+TbAYfw X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id XX2_yaYmIdqx; Tue, 21 Jun 2022 14:48:35 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp3.osuosl.org (Postfix) with ESMTPS id A1AED60D62; Tue, 21 Jun 2022 14:48:34 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org A1AED60D62 Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7E15FC0039; Tue, 21 Jun 2022 14:48:34 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id CE743C002D for ; Tue, 21 Jun 2022 14:48:33 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id A957F60BBB for ; Tue, 21 Jun 2022 14:48:33 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org A957F60BBB X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id gZX9RRXqCggr for ; Tue, 21 Jun 2022 14:48:32 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 7FF4B60FDF Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by smtp3.osuosl.org (Postfix) with ESMTPS id 7FF4B60FDF for ; Tue, 21 Jun 2022 14:48:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1655822912; x=1687358912; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=23hC2f4dgyTyX4xCupRfbmP4pCP+etJyCkXoUnCA06c=; b=R+TbAYfw8ewkSg7/1lArpPJAnmOBWpm5mraDm3jZSUXYBFa+aFVynnG4 JP5pQrdOBjKlRhrfgQ0XcAU9OtSqs7K5Tbt2nveh3Pq109g+P4y56J/M9 N+SL4UzQU0jOP3+slwx+T4fOqjh7EtTapq6dODDi6FCvMf4WutM8XE8jY gGQxxVrO69sQRTkF6xcSVcEoBpv5MdSpKb9aDDeLSKq+pNLURFfEuctZS Onq8Tl56B/yziN/3+4byzY3D6CeJuJCK+/I/8+grvMleuFk6AR1ftjAwe GmEf77cG+T9k28REqd+E/rQ6QQYefWqlrcxw+OeJkOPxs5l/8UrxmRT6Z w==; X-IronPort-AV: E=McAfee;i="6400,9594,10384"; a="280867175" X-IronPort-AV: E=Sophos;i="5.92,209,1650956400"; d="scan'208";a="280867175" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jun 2022 07:48:32 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,209,1650956400"; d="scan'208";a="643659433" Received: from allen-box.sh.intel.com ([10.239.159.48]) by fmsmga008.fm.intel.com with ESMTP; 21 Jun 2022 07:48:28 -0700 From: Lu Baolu To: Joerg Roedel , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj , Will Deacon , Robin Murphy , Jean-Philippe Brucker , Dave Jiang , Vinod Koul Subject: [PATCH v9 07/11] iommu/sva: Refactoring iommu_sva_bind/unbind_device() Date: Tue, 21 Jun 2022 22:43:49 +0800 Message-Id: <20220621144353.17547-8-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220621144353.17547-1-baolu.lu@linux.intel.com> References: <20220621144353.17547-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Jacob jun Pan X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" The existing iommu SVA interfaces are implemented by calling the SVA specific iommu ops provided by the IOMMU drivers. There's no need for any SVA specific ops in iommu_ops vector anymore as we can achieve this through the generic attach/detach_dev_pasid domain ops. This refactors the IOMMU SVA interfaces implementation by using the set/block_pasid_dev ops and align them with the concept of the SVA iommu domain. Put the new SVA code in the sva related file in order to make it self-contained. Signed-off-by: Lu Baolu --- include/linux/iommu.h | 67 +++++++++++-------- drivers/iommu/iommu-sva-lib.c | 98 ++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 119 ++++++++-------------------------- 3 files changed, 165 insertions(+), 119 deletions(-) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index b8b6b8c5e20e..c0c23d9fd8fe 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -39,7 +39,6 @@ struct device; struct iommu_domain; struct iommu_domain_ops; struct notifier_block; -struct iommu_sva; struct iommu_fault_event; struct iommu_dma_cookie; @@ -57,6 +56,14 @@ struct iommu_domain_geometry { bool force_aperture; /* DMA only allowed in mappable range? */ }; +/** + * struct iommu_sva - handle to a device-mm bond + */ +struct iommu_sva { + struct device *dev; + refcount_t users; +}; + /* Domain feature flags */ #define __IOMMU_DOMAIN_PAGING (1U << 0) /* Support for iommu_map/unmap */ #define __IOMMU_DOMAIN_DMA_API (1U << 1) /* Domain for use in DMA-API @@ -105,6 +112,7 @@ struct iommu_domain { }; struct { /* IOMMU_DOMAIN_SVA */ struct mm_struct *mm; + struct iommu_sva bond; }; }; }; @@ -638,13 +646,6 @@ struct iommu_fwspec { /* ATS is supported */ #define IOMMU_FWSPEC_PCI_RC_ATS (1 << 0) -/** - * struct iommu_sva - handle to a device-mm bond - */ -struct iommu_sva { - struct device *dev; -}; - int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode, const struct iommu_ops *ops); void iommu_fwspec_free(struct device *dev); @@ -685,11 +686,6 @@ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f); int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f); bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f); -struct iommu_sva *iommu_sva_bind_device(struct device *dev, - struct mm_struct *mm); -void iommu_sva_unbind_device(struct iommu_sva *handle); -u32 iommu_sva_get_pasid(struct iommu_sva *handle); - int iommu_device_use_default_domain(struct device *dev); void iommu_device_unuse_default_domain(struct device *dev); @@ -703,6 +699,8 @@ int iommu_attach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid); +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid); #else /* CONFIG_IOMMU_API */ struct iommu_ops {}; @@ -1033,21 +1031,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) return -ENODEV; } -static inline struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) -{ - return NULL; -} - -static inline void iommu_sva_unbind_device(struct iommu_sva *handle) -{ -} - -static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - return IOMMU_PASID_INVALID; -} - static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev) { return NULL; @@ -1093,6 +1076,12 @@ static inline void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, ioasid_t pasid) { } + +static inline struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid) +{ + return NULL; +} #endif /* CONFIG_IOMMU_API */ /** @@ -1118,4 +1107,26 @@ void iommu_debugfs_setup(void); static inline void iommu_debugfs_setup(void) {} #endif +#ifdef CONFIG_IOMMU_SVA +struct iommu_sva *iommu_sva_bind_device(struct device *dev, + struct mm_struct *mm); +void iommu_sva_unbind_device(struct iommu_sva *handle); +u32 iommu_sva_get_pasid(struct iommu_sva *handle); +#else +static inline struct iommu_sva * +iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) +{ + return NULL; +} + +static inline void iommu_sva_unbind_device(struct iommu_sva *handle) +{ +} + +static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + return IOMMU_PASID_INVALID; +} +#endif /* CONFIG_IOMMU_SVA */ + #endif /* __LINUX_IOMMU_H */ diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c index 106506143896..1e3e2b395b1e 100644 --- a/drivers/iommu/iommu-sva-lib.c +++ b/drivers/iommu/iommu-sva-lib.c @@ -4,6 +4,7 @@ */ #include #include +#include #include "iommu-sva-lib.h" @@ -69,3 +70,100 @@ struct mm_struct *iommu_sva_find(ioasid_t pasid) return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero); } EXPORT_SYMBOL_GPL(iommu_sva_find); + +/** + * iommu_sva_bind_device() - Bind a process address space to a device + * @dev: the device + * @mm: the mm to bind, caller must hold a reference to mm_users + * + * Create a bond between device and address space, allowing the device to access + * the mm using the returned PASID. If a bond already exists between @device and + * @mm, it is returned and an additional reference is taken. Caller must call + * iommu_sva_unbind_device() to release each reference. + * + * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to + * initialize the required SVA features. + * + * On error, returns an ERR_PTR value. + */ +struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) +{ + struct iommu_domain *domain; + ioasid_t max_pasids; + int ret = -EINVAL; + + /* Allocate mm->pasid if necessary. */ + max_pasids = dev->iommu->max_pasids; + if (!max_pasids) + return ERR_PTR(-EOPNOTSUPP); + + ret = iommu_sva_alloc_pasid(mm, 1, max_pasids - 1); + if (ret) + return ERR_PTR(ret); + + mutex_lock(&iommu_sva_lock); + /* Search for an existing domain. */ + domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid); + if (domain) { + refcount_inc(&domain->bond.users); + goto out_success; + } + + /* Allocate a new domain and set it on device pasid. */ + domain = iommu_sva_domain_alloc(dev, mm); + if (!domain) { + ret = -ENOMEM; + goto out_unlock; + } + + ret = iommu_attach_device_pasid(domain, dev, mm->pasid); + if (ret) + goto out_free_domain; + domain->bond.dev = dev; + refcount_set(&domain->bond.users, 1); + +out_success: + mutex_unlock(&iommu_sva_lock); + return &domain->bond; + +out_free_domain: + iommu_domain_free(domain); +out_unlock: + mutex_unlock(&iommu_sva_lock); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(iommu_sva_bind_device); + +/** + * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device + * @handle: the handle returned by iommu_sva_bind_device() + * + * Put reference to a bond between device and address space. The device should + * not be issuing any more transaction for this PASID. All outstanding page + * requests for this PASID must have been flushed to the IOMMU. + */ +void iommu_sva_unbind_device(struct iommu_sva *handle) +{ + struct device *dev = handle->dev; + struct iommu_domain *domain = + container_of(handle, struct iommu_domain, bond); + ioasid_t pasid = iommu_sva_get_pasid(handle); + + mutex_lock(&iommu_sva_lock); + if (refcount_dec_and_test(&domain->bond.users)) { + iommu_detach_device_pasid(domain, dev, pasid); + iommu_domain_free(domain); + } + mutex_unlock(&iommu_sva_lock); +} +EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); + +u32 iommu_sva_get_pasid(struct iommu_sva *handle) +{ + struct iommu_domain *domain = + container_of(handle, struct iommu_domain, bond); + + return domain->mm->pasid; +} +EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 8450f914cb2b..34d71418e7c7 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2789,97 +2789,6 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat) } EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled); -/** - * iommu_sva_bind_device() - Bind a process address space to a device - * @dev: the device - * @mm: the mm to bind, caller must hold a reference to it - * - * Create a bond between device and address space, allowing the device to access - * the mm using the returned PASID. If a bond already exists between @device and - * @mm, it is returned and an additional reference is taken. Caller must call - * iommu_sva_unbind_device() to release each reference. - * - * iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) must be called first, to - * initialize the required SVA features. - * - * On error, returns an ERR_PTR value. - */ -struct iommu_sva * -iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) -{ - struct iommu_group *group; - struct iommu_sva *handle = ERR_PTR(-EINVAL); - const struct iommu_ops *ops = dev_iommu_ops(dev); - - if (!ops->sva_bind) - return ERR_PTR(-ENODEV); - - group = iommu_group_get(dev); - if (!group) - return ERR_PTR(-ENODEV); - - /* Ensure device count and domain don't change while we're binding */ - mutex_lock(&group->mutex); - - /* - * To keep things simple, SVA currently doesn't support IOMMU groups - * with more than one device. Existing SVA-capable systems are not - * affected by the problems that required IOMMU groups (lack of ACS - * isolation, device ID aliasing and other hardware issues). - */ - if (iommu_group_device_count(group) != 1) - goto out_unlock; - - handle = ops->sva_bind(dev, mm); - -out_unlock: - mutex_unlock(&group->mutex); - iommu_group_put(group); - - return handle; -} -EXPORT_SYMBOL_GPL(iommu_sva_bind_device); - -/** - * iommu_sva_unbind_device() - Remove a bond created with iommu_sva_bind_device - * @handle: the handle returned by iommu_sva_bind_device() - * - * Put reference to a bond between device and address space. The device should - * not be issuing any more transaction for this PASID. All outstanding page - * requests for this PASID must have been flushed to the IOMMU. - */ -void iommu_sva_unbind_device(struct iommu_sva *handle) -{ - struct iommu_group *group; - struct device *dev = handle->dev; - const struct iommu_ops *ops = dev_iommu_ops(dev); - - if (!ops->sva_unbind) - return; - - group = iommu_group_get(dev); - if (!group) - return; - - mutex_lock(&group->mutex); - ops->sva_unbind(handle); - mutex_unlock(&group->mutex); - - iommu_group_put(group); -} -EXPORT_SYMBOL_GPL(iommu_sva_unbind_device); - -u32 iommu_sva_get_pasid(struct iommu_sva *handle) -{ - const struct iommu_ops *ops = dev_iommu_ops(handle->dev); - - if (!ops->sva_get_pasid) - return IOMMU_PASID_INVALID; - - return ops->sva_get_pasid(handle); -} -EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); - /* * Changes the default domain of an iommu group that has *only* one device * @@ -3364,3 +3273,31 @@ void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev, iommu_group_put(group); } + +/* + * This is a variant of iommu_get_domain_for_dev(). It returns the existing + * domain attached to pasid of a device. It's only for internal use of the + * IOMMU subsystem. The caller must take care to avoid any possible + * use-after-free case. + */ +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid) +{ + struct iommu_domain *domain; + struct iommu_group *group; + + if (!pasid_valid(pasid)) + return NULL; + + group = iommu_group_get(dev); + if (!group) + return NULL; + /* + * The xarray protects its internal state with RCU. Hence the domain + * obtained is either NULL or fully formed. + */ + domain = xa_load(&group->pasid_array, pasid); + iommu_group_put(group); + + return domain; +} -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu