From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 5D0307DE6F for ; Mon, 3 Sep 2018 00:53:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726046AbeICFKH (ORCPT ); Mon, 3 Sep 2018 01:10:07 -0400 Received: from mail-pl1-f195.google.com ([209.85.214.195]:46124 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725762AbeICFKG (ORCPT ); Mon, 3 Sep 2018 01:10:06 -0400 Received: by mail-pl1-f195.google.com with SMTP id t19-v6so110251ply.13; Sun, 02 Sep 2018 17:52:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=PqNEZCF3NFy3Jzxsnv6juVWEGf6EoQqZyW/gnVxyV+M=; b=nZQ6Fj3YkpjhrG+K+fDsDVinPrzX48NDfx7hCJNHveoRnUUX2Dl97U9nWbe5pFEO2Y DDjK6MsdoN5exy2lz1qchFT3hiS8HzLO4WycB+I6eNNARhX2aLXJ5x+UtDSk44C4jR6e ja9xRrTWgTfovwLvvd9XH/4+o6dMLteoN3JZPLFyfnZgwR2QvWYZlCPMnukV/ODO0+5V 4vKNCGycErrIwPAs7Ijzpyqa08m17DYKh6o+gHNRo5WRh6JHeriDHUfOoRReeiNahuDh vfs3ZTPLPUcF4mGYCCG8Ni6kGmTXrHtNW6BKyS/wkHvNa7b2aVmwxp53H/crlo2rb/oo jJVg== 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; bh=PqNEZCF3NFy3Jzxsnv6juVWEGf6EoQqZyW/gnVxyV+M=; b=JYftu6s2e065P5f4URi6ReGNKMvC7UlGsHzIhh85XWIRAKHwVqlP9mJxzfR24+SEW6 Z9NqKVWYQP+ZyBfxrisqbpY2Rqx7z5n3kL9syIIs2mDwIHhfpTENYUW5EP4nM35c70Ge aNahxJk7fMLjLX9y+RfHXtmykrUDROFZHaHiQEcljERiPh9nUf7p1pMWiVKTUDsi3dur YLuOn6UpYpLlaJ5k1UHFIyhHjJwPwODuXFgP7poGFpA/mqEmk+zX/PHoKtUekmWWsd0R O+4d+gwaqsuCaksSEiwuBff4fgzS6vY370OHD7Atx1MiJtZc8DzfesYx/LdW9tgwF2mm c+QA== X-Gm-Message-State: APzg51A6QK2WxwH0fvnj14vDwmFX7Ci8HbVgKypCdWxuxKxIQKp6ThQ6 INJY2xVlbvFwHvY8+BmHTfk= X-Google-Smtp-Source: ANB0VdbR8+ime6YzcNp/WX8x8dusjqplYqeTH/woZbX5KMbL0sk4tL3z2wpiCtAVAPzNHXykclcPDg== X-Received: by 2002:a17:902:8a92:: with SMTP id p18-v6mr25383105plo.148.1535935946150; Sun, 02 Sep 2018 17:52:26 -0700 (PDT) Received: from localhost.localdomain ([203.160.89.93]) by smtp.gmail.com with ESMTPSA id w81-v6sm31487064pfk.92.2018.09.02.17.52.21 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 02 Sep 2018 17:52:25 -0700 (PDT) From: Kenneth Lee To: Jonathan Corbet , Herbert Xu , "David S . Miller" , Joerg Roedel , Alex Williamson , Kenneth Lee , Hao Fang , Zhou Wang , Zaibo Xu , Philippe Ombredanne , Greg Kroah-Hartman , Thomas Gleixner , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, iommu@lists.linux-foundation.org, kvm@vger.kernel.org, linux-accelerators@lists.ozlabs.org, Lu Baolu , Sanjay Kumar Cc: linuxarm@huawei.com Subject: [PATCH 2/7] iommu: Add share domain interface in iommu for sdmdev Date: Mon, 3 Sep 2018 08:51:59 +0800 Message-Id: <20180903005204.26041-3-nek.in.cn@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180903005204.26041-1-nek.in.cn@gmail.com> References: <20180903005204.26041-1-nek.in.cn@gmail.com> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Kenneth Lee This patch add sharing interface for a iommu_group. The new interface: iommu_group_share_domain() iommu_group_unshare_domain() can be used by some virtual iommu_group (such as iommu_group of sdmdev) to share their parent's iommu_group. When the domain of a group is shared, it cannot be changed before being unshared. By this way, all domain users can assume the shared IOMMU have the same configuration. In the future, notification can be added if update is required. Signed-off-by: Kenneth Lee --- drivers/iommu/iommu.c | 29 ++++++++++++++++++++++++++++- include/linux/iommu.h | 15 +++++++++++++++ 2 files changed, 43 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 8c15c5980299..8e567e1037dd 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -58,6 +58,9 @@ struct iommu_group { int id; struct iommu_domain *default_domain; struct iommu_domain *domain; + atomic_t domain_shared_ref; /* Number of user of current domain. + * The domain cannot be modified if ref > 0 + */ }; struct group_device { @@ -385,6 +388,7 @@ struct iommu_group *iommu_group_alloc(void) return ERR_PTR(ret); } group->id = ret; + atomic_set(&group->domain_shared_ref, 0); ret = kobject_init_and_add(&group->kobj, &iommu_group_ktype, NULL, "%d", group->id); @@ -518,6 +522,26 @@ int iommu_group_set_name(struct iommu_group *group, const char *name) } EXPORT_SYMBOL_GPL(iommu_group_set_name); +struct iommu_domain *iommu_group_share_domain(struct iommu_group *group) +{ + /* the domain can be shared only when the default domain is used */ + /* todo: more shareable check */ + if (group->domain != group->default_domain) + return ERR_PTR(-EINVAL); + + atomic_inc(&group->domain_shared_ref); + return group->domain; +} +EXPORT_SYMBOL_GPL(iommu_group_share_domain); + +struct iommu_domain *iommu_group_unshare_domain(struct iommu_group *group) +{ + atomic_dec(&group->domain_shared_ref); + WARN_ON(atomic_read(&group->domain_shared_ref) < 0); + return group->domain; +} +EXPORT_SYMBOL_GPL(iommu_group_unshare_domain); + static int iommu_group_create_direct_mappings(struct iommu_group *group, struct device *dev) { @@ -1437,7 +1461,8 @@ static int __iommu_attach_group(struct iommu_domain *domain, { int ret; - if (group->default_domain && group->domain != group->default_domain) + if ((group->default_domain && group->domain != group->default_domain) || + atomic_read(&group->domain_shared_ref) > 0) return -EBUSY; ret = __iommu_group_for_each_dev(group, domain, @@ -1474,6 +1499,8 @@ static void __iommu_detach_group(struct iommu_domain *domain, { int ret; + WARN_ON(atomic_read(&group->domain_shared_ref) > 0); + if (!group->default_domain) { __iommu_group_for_each_dev(group, domain, iommu_group_do_detach_device); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 87994c265bf5..013ac400b643 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -344,6 +344,9 @@ extern int iommu_domain_get_attr(struct iommu_domain *domain, enum iommu_attr, void *data); extern int iommu_domain_set_attr(struct iommu_domain *domain, enum iommu_attr, void *data); +extern struct iommu_domain *iommu_group_share_domain(struct iommu_group *group); +extern struct iommu_domain *iommu_group_unshare_domain( + struct iommu_group *group); /* Window handling function prototypes */ extern int iommu_domain_window_enable(struct iommu_domain *domain, u32 wnd_nr, @@ -616,6 +619,18 @@ static inline int iommu_domain_set_attr(struct iommu_domain *domain, return -EINVAL; } +static inline struct iommu_domain *iommu_group_share_domain( + struct iommu_group *group) +{ + return NULL; +} + +static inline struct iommu_domain *iommu_group_unshare_domain( + struct iommu_group *group) +{ + return NULL; +} + static inline int iommu_device_register(struct iommu_device *iommu) { return -ENODEV; -- 2.17.1