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=-9.8 required=3.0 tests=BAYES_00,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 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 0710FC55178 for ; Wed, 21 Oct 2020 14:56:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 99EFC22249 for ; Wed, 21 Oct 2020 14:56:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="XzjZcHSj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2443794AbgJUO4Q (ORCPT ); Wed, 21 Oct 2020 10:56:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2443093AbgJUO4Q (ORCPT ); Wed, 21 Oct 2020 10:56:16 -0400 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8C85C0613CF for ; Wed, 21 Oct 2020 07:56:14 -0700 (PDT) Received: by mail-ej1-x643.google.com with SMTP id z5so3665849ejw.7 for ; Wed, 21 Oct 2020 07:56:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=i0gECfOlPfz4plZ33A4BfSfMxdYGdEP0cLl7pBtvXaM=; b=XzjZcHSjZXU0yf53/9wPdvVLf1gFij1CZpuVEV2Ib1JjRNIk7jxzJMLsvBrjYs5ikF v9JUp20+Qor4344t0egWSBOWII9beWxmRqyJHFpCkdpDDtj3LGFpcTzWCnKWMK3QpnhQ LpsEKbtXThYFsW0Xg/r6RC0JaST3EIPGiSHFPZJofl+qpTMhNLJWRHbaExSn1cUMIQi3 SajDFTant3KJx8eF+Y2v5p13SXyu3yj2r2opfPWJ3/5GZVQMcfU//zSCyOPygNWfK+bc WeEYHLNRFC9yYrCKRPNwLUz9jZCZ6ssz0UTFMOpRzqrK+LQcoQFEJTFbNziDAAmb6XYR 3+8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=i0gECfOlPfz4plZ33A4BfSfMxdYGdEP0cLl7pBtvXaM=; b=eEi6z4WAovFI8pMuoL7AOn4X8eh8btlCu8/nIgVDZQHiKjVQBBtxXJ6g+UgepyrmOK 4/2FuYb0rCeJTHRn5H2+DKOWiDOZU1nNuNGY9s9Q06w0w4XQsC/Jnz+Idx0iFZ9wdc6/ nrIdhp9nsdyjTxS/6BkS6uhdum/1v8hm2PQ5VaR8sOqm1/QgQCcm2yFvEaWy4+0w1ulm w51Aq3nZ9duKFYFdJpDMkKBwzVzBvWC5nBeGQBiPgtM6BthOjgUdz1kSLQ2UEOCAfR9H 8i3j05XmKGoWjsCQ78ZtVjhEILdJtSu0k1j6+zYpneCRhq7S07yNUCELtfeMNfxC5XEn S7nA== X-Gm-Message-State: AOAM531I01jRC1vXyXvw3sBYU8yBIujlrORfqGXWbzv4WsWetW3r9TDN C3KliZXTWu7QwHsmKHvwECTmZQ== X-Google-Smtp-Source: ABdhPJwtYRoCsFDqCEseN621ZJOAl2v4bYAaS/QMvNGP6/fwIxcx7B5B9IoZDL6/DLX2klAcx1Fizg== X-Received: by 2002:a17:906:e116:: with SMTP id gj22mr4061068ejb.313.1603292173166; Wed, 21 Oct 2020 07:56:13 -0700 (PDT) Received: from myrica ([2001:1715:4e26:a7e0:116c:c27a:3e7f:5eaf]) by smtp.gmail.com with ESMTPSA id b13sm2230700edk.22.2020.10.21.07.56.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Oct 2020 07:56:12 -0700 (PDT) Date: Wed, 21 Oct 2020 16:55:53 +0200 From: Jean-Philippe Brucker To: Jacob Pan Cc: iommu@lists.linux-foundation.org, LKML , Joerg Roedel , Alex Williamson , Lu Baolu , David Woodhouse , Jonathan Corbet , linux-api@vger.kernel.org, Jean-Philippe Brucker , Eric Auger , Jacob Pan , Yi Liu , "Tian, Kevin" , Raj Ashok , Wu Hao , Yi Sun , Dave Jiang , Randy Dunlap Subject: Re: [PATCH v3 05/14] iommu/ioasid: Redefine IOASID set and allocation APIs Message-ID: <20201021145553.GC1653231@myrica> References: <1601329121-36979-1-git-send-email-jacob.jun.pan@linux.intel.com> <1601329121-36979-6-git-send-email-jacob.jun.pan@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1601329121-36979-6-git-send-email-jacob.jun.pan@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 28, 2020 at 02:38:32PM -0700, Jacob Pan wrote: > ioasid_set was introduced as an arbitrary token that is shared by a > group of IOASIDs. For example, two IOASIDs allocated via the same > ioasid_set pointer belong to the same set. > > For guest SVA usages, system-wide IOASID resources need to be > partitioned such that each VM can have its own quota and being managed > separately. ioasid_set is the perfect candidate for meeting such > requirements. This patch redefines and extends ioasid_set with the > following new fields: > - Quota > - Reference count > - Storage of its namespace > - The token is now stored in the ioasid_set with types > > Basic ioasid_set level APIs are introduced that wire up these new data. > Existing users of IOASID APIs are converted where a host IOASID set is > allocated for bare-metal usage. > > Signed-off-by: Liu Yi L > Signed-off-by: Jacob Pan > --- > drivers/iommu/intel/iommu.c | 26 +++-- > drivers/iommu/intel/pasid.h | 1 + > drivers/iommu/intel/svm.c | 25 ++-- > drivers/iommu/ioasid.c | 277 ++++++++++++++++++++++++++++++++++++++++---- > include/linux/ioasid.h | 53 +++++++-- > 5 files changed, 333 insertions(+), 49 deletions(-) > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > index e7bcb299e51e..872391890323 100644 > --- a/drivers/iommu/intel/iommu.c > +++ b/drivers/iommu/intel/iommu.c > @@ -104,6 +104,9 @@ > */ > #define INTEL_IOMMU_PGSIZES (~0xFFFUL) > > +/* PASIDs used by host SVM */ > +struct ioasid_set *host_pasid_set; > + > static inline int agaw_to_level(int agaw) > { > return agaw + 2; > @@ -3147,8 +3150,8 @@ static void intel_vcmd_ioasid_free(ioasid_t ioasid, void *data) > * Sanity check the ioasid owner is done at upper layer, e.g. VFIO > * We can only free the PASID when all the devices are unbound. > */ > - if (ioasid_find(NULL, ioasid, NULL)) { > - pr_alert("Cannot free active IOASID %d\n", ioasid); > + if (IS_ERR(ioasid_find(host_pasid_set, ioasid, NULL))) { > + pr_err("IOASID %d to be freed but not in system set\n", ioasid); > return; > } > vcmd_free_pasid(iommu, ioasid); > @@ -3333,8 +3336,17 @@ static int __init init_dmars(void) > goto free_iommu; > > /* PASID is needed for scalable mode irrespective to SVM */ > - if (intel_iommu_sm) > + if (intel_iommu_sm) { > ioasid_install_capacity(intel_pasid_max_id); > + /* We should not run out of IOASIDs at boot */ > + host_pasid_set = ioasid_set_alloc(NULL, PID_MAX_DEFAULT, > + IOASID_SET_TYPE_NULL); > + if (IS_ERR_OR_NULL(host_pasid_set)) { > + pr_err("Failed to allocate host PASID set %lu\n", Printing a negative value as unsigned > + PTR_ERR(host_pasid_set)); > + intel_iommu_sm = 0; > + } > + } > > /* > * for each drhd > @@ -3381,7 +3393,7 @@ static int __init init_dmars(void) > disable_dmar_iommu(iommu); > free_dmar_iommu(iommu); > } > - > + ioasid_set_put(host_pasid_set); > kfree(g_iommus); > > error: > @@ -5163,7 +5175,7 @@ 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_free(host_pasid_set, domain->default_pasid); > } > > static int aux_domain_add_dev(struct dmar_domain *domain, > @@ -5181,7 +5193,7 @@ static int aux_domain_add_dev(struct dmar_domain *domain, > int pasid; > > /* No private data needed for the default pasid */ > - pasid = ioasid_alloc(NULL, PASID_MIN, > + pasid = ioasid_alloc(host_pasid_set, PASID_MIN, > pci_max_pasids(to_pci_dev(dev)) - 1, > NULL); > if (pasid == INVALID_IOASID) { > @@ -5224,7 +5236,7 @@ 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_free(host_pasid_set, domain->default_pasid); > > return ret; > } > diff --git a/drivers/iommu/intel/pasid.h b/drivers/iommu/intel/pasid.h > index c9850766c3a9..ccdc23446015 100644 > --- a/drivers/iommu/intel/pasid.h > +++ b/drivers/iommu/intel/pasid.h > @@ -99,6 +99,7 @@ static inline bool pasid_pte_is_present(struct pasid_entry *pte) > } > > extern u32 intel_pasid_max_id; > +extern struct ioasid_set *host_pasid_set; > int intel_pasid_alloc_id(void *ptr, int start, int end, gfp_t gfp); > void intel_pasid_free_id(int pasid); > void *intel_pasid_lookup_id(int pasid); > diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c > index 06a16bee7b65..2e764e283469 100644 > --- a/drivers/iommu/intel/svm.c > +++ b/drivers/iommu/intel/svm.c > @@ -228,7 +228,9 @@ static LIST_HEAD(global_svm_list); > list_for_each_entry((sdev), &(svm)->devs, list) \ > if ((d) != (sdev)->dev) {} else > > -static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid, > +static int pasid_to_svm_sdev(struct device *dev, > + struct ioasid_set *set, > + unsigned int pasid, > struct intel_svm **rsvm, > struct intel_svm_dev **rsdev) > { > @@ -242,7 +244,7 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid, > if (pasid == INVALID_IOASID || pasid >= PASID_MAX) > return -EINVAL; > > - svm = ioasid_find(NULL, pasid, NULL); > + svm = ioasid_find(set, pasid, NULL); > if (IS_ERR(svm)) > return PTR_ERR(svm); > > @@ -312,7 +314,8 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, > dmar_domain = to_dmar_domain(domain); > > mutex_lock(&pasid_mutex); > - ret = pasid_to_svm_sdev(dev, data->hpasid, &svm, &sdev); > + ret = pasid_to_svm_sdev(dev, NULL, > + data->hpasid, &svm, &sdev); > if (ret) > goto out; > > @@ -417,7 +420,7 @@ int intel_svm_unbind_gpasid(struct device *dev, int pasid) > return -EINVAL; > > mutex_lock(&pasid_mutex); > - ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev); > + ret = pasid_to_svm_sdev(dev, NULL, pasid, &svm, &sdev); > if (ret) > goto out; > > @@ -555,7 +558,7 @@ intel_svm_bind_mm(struct device *dev, int flags, struct svm_dev_ops *ops, > pasid_max = intel_pasid_max_id; > > /* Do not use PASID 0, reserved for RID to PASID */ > - svm->pasid = ioasid_alloc(NULL, PASID_MIN, > + svm->pasid = ioasid_alloc(host_pasid_set, PASID_MIN, > pasid_max - 1, svm); > if (svm->pasid == INVALID_IOASID) { > kfree(svm); > @@ -572,7 +575,7 @@ 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_free(host_pasid_set, svm->pasid); > kfree(svm); > kfree(sdev); > goto out; > @@ -590,7 +593,7 @@ 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_free(host_pasid_set, svm->pasid); > kfree(svm); > kfree(sdev); > goto out; > @@ -638,7 +641,8 @@ static int intel_svm_unbind_mm(struct device *dev, int pasid) > if (!iommu) > goto out; > > - ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev); > + ret = pasid_to_svm_sdev(dev, host_pasid_set, > + pasid, &svm, &sdev); > if (ret) > goto out; > > @@ -659,7 +663,7 @@ 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_free(host_pasid_set, svm->pasid); > if (svm->mm) > mmu_notifier_unregister(&svm->notifier, svm->mm); > list_del(&svm->list); > @@ -1130,7 +1134,8 @@ int intel_svm_page_response(struct device *dev, > goto out; > } > > - ret = pasid_to_svm_sdev(dev, prm->pasid, &svm, &sdev); > + ret = pasid_to_svm_sdev(dev, host_pasid_set, > + prm->pasid, &svm, &sdev); > if (ret || !sdev) { > ret = -ENODEV; > goto out; > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c > index 4277cb17e15b..61e25c2375ab 100644 > --- a/drivers/iommu/ioasid.c > +++ b/drivers/iommu/ioasid.c > @@ -1,8 +1,8 @@ > // SPDX-License-Identifier: GPL-2.0 > /* > * 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. > + * sets. Users create a set with ioasid_set_alloc, then allocate/free IDs > + * with ioasid_alloc and ioasid_free. > */ > #include > #include > @@ -14,6 +14,8 @@ > #define PCI_PASID_MAX 0x100000 > static ioasid_t ioasid_capacity = PCI_PASID_MAX; > static ioasid_t ioasid_capacity_avail = PCI_PASID_MAX; > +static DEFINE_XARRAY_ALLOC(ioasid_sets); > + > struct ioasid_data { > ioasid_t id; > struct ioasid_set *set; > @@ -343,6 +345,114 @@ void ioasid_detach_data(ioasid_t ioasid) > } > EXPORT_SYMBOL_GPL(ioasid_detach_data); > > +static inline bool ioasid_set_is_valid(struct ioasid_set *set) 'inline' isn't needed > +{ > + return xa_load(&ioasid_sets, set->id) == set; > +} > + > +/** > + * ioasid_set_alloc - Allocate a new IOASID set for a given token > + * > + * @token: An optional arbitrary number that can be associated with the > + * IOASID set. @token can be NULL if the type is > + * IOASID_SET_TYPE_NULL > + * @quota: Quota allowed in this set > + * @type: The type of the token used to create the IOASID set > + * > + * IOASID is limited system-wide resource that requires quota management. > + * Token will be stored in the ioasid_set returned. A reference will be taken > + * on the newly created set. Subsequent IOASID allocation within the set need > + * to use the retured ioasid_set pointer. returned > + */ > +struct ioasid_set *ioasid_set_alloc(void *token, ioasid_t quota, int type) > +{ > + struct ioasid_set *set; > + unsigned long index; > + ioasid_t id; > + > + if (type >= IOASID_SET_TYPE_NR) > + return ERR_PTR(-EINVAL); > + > + /* REVISIT: may support set w/o quota, use system available */ You can drop this comment, anyone wanting to pass a quota of zero can send a patch. > + if (!quota) > + return ERR_PTR(-EINVAL); > + > + /* > + * Need to check space available if we share system-wide quota. > + * TODO: we may need to support quota free sets in the future. You can drop this too > + */ > + spin_lock(&ioasid_allocator_lock); > + if (quota > ioasid_capacity_avail) { > + pr_warn("Out of IOASID capacity! ask %d, avail %d\n", > + quota, ioasid_capacity_avail); > + set = ERR_PTR(-ENOSPC); > + goto exit_unlock; > + } > + > + /* > + * Token is only unique within its types but right now we have only > + * mm type. If we have more token types, we have to match type as well. > + */ > + switch (type) { > + case IOASID_SET_TYPE_MM: > + if (!token) { > + set = ERR_PTR(-EINVAL); > + goto exit_unlock; > + } > + /* Search existing set tokens, reject duplicates */ > + xa_for_each(&ioasid_sets, index, set) { > + if (set->token == token && > + set->type == IOASID_SET_TYPE_MM) { misaligned > + set = ERR_PTR(-EEXIST); > + goto exit_unlock; > + } > + } > + break; > + case IOASID_SET_TYPE_NULL: > + if (!token) > + break; > + fallthrough; > + default: > + pr_err("Invalid token and IOASID type\n"); > + set = ERR_PTR(-EINVAL); > + goto exit_unlock; > + } > + > + set = kzalloc(sizeof(*set), GFP_ATOMIC); > + if (!set) { > + set = ERR_PTR(-ENOMEM); > + goto exit_unlock; > + } > + > + if (xa_alloc(&ioasid_sets, &id, set, > + XA_LIMIT(0, ioasid_capacity_avail - quota), > + GFP_ATOMIC)) { > + kfree(set); > + set = ERR_PTR(-ENOSPC); > + goto exit_unlock; > + } > + > + set->token = token; > + set->type = type; > + set->quota = quota; > + set->id = id; > + refcount_set(&set->ref, 1); > + > + /* > + * Per set XA is used to store private IDs within the set, get ready Could drop "get ready". But I think the comment on the ioasid_set struct is sufficient, maybe you can drop this whole comment. > + * for ioasid_set private ID and system-wide IOASID allocation > + * results. > + */ > + xa_init(&set->xa); > + ioasid_capacity_avail -= quota; > + > +exit_unlock: > + spin_unlock(&ioasid_allocator_lock); > + > + return set; > +} > +EXPORT_SYMBOL_GPL(ioasid_set_alloc); > + > /** > * ioasid_alloc - Allocate an IOASID > * @set: the IOASID set > @@ -360,11 +470,22 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, > { > struct ioasid_data *data; > void *adata; > - ioasid_t id; > + ioasid_t id = INVALID_IOASID; > + > + spin_lock(&ioasid_allocator_lock); > + /* Check if the IOASID set has been allocated and initialized */ > + if (WARN_ON(!ioasid_set_is_valid(set))) > + goto done_unlock; > + > + if (set->quota <= set->nr_ioasids) { > + pr_err_ratelimited("IOASID set out of quota %d\n", > + set->quota); > + goto done_unlock; > + } > > data = kzalloc(sizeof(*data), GFP_ATOMIC); > if (!data) > - return INVALID_IOASID; > + goto done_unlock; > > data->set = set; > data->private = private; > @@ -373,11 +494,10 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, > * Custom allocator needs allocator data to perform platform specific > * operations. > */ > - spin_lock(&ioasid_allocator_lock); > adata = active_allocator->flags & IOASID_ALLOCATOR_CUSTOM ? active_allocator->ops->pdata : data; > id = active_allocator->ops->alloc(min, max, adata); > if (id == INVALID_IOASID) { > - pr_err("Failed ASID allocation %lu\n", active_allocator->flags); > + pr_err_ratelimited("Failed IOASID allocation %lu\n", active_allocator->flags); > goto exit_free; > } > > @@ -386,46 +506,153 @@ ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, > /* Custom allocator needs framework to store and track allocation results */ > pr_err("Failed to alloc ioasid from %d\n", id); > active_allocator->ops->free(id, active_allocator->ops->pdata); > + if (active_allocator->flags & IOASID_ALLOCATOR_CUSTOM) > + xa_erase(&active_allocator->xa, id); That doesn't look right, given we get here if the CUSTOM flag is set and xa_alloc() fails. Should it be in the next block? > goto exit_free; > } > data->id = id; > > - spin_unlock(&ioasid_allocator_lock); > - return id; > + /* Store IOASID in the per set data */ > + if (xa_err(xa_store(&set->xa, id, data, GFP_ATOMIC))) { > + pr_err_ratelimited("Failed to store ioasid %d in set\n", id); > + active_allocator->ops->free(id, active_allocator->ops->pdata); > + goto exit_free; Should set id = INVALID_IOASID. I feel this function would be more readable if we keep separate error and success paths. > + } > + set->nr_ioasids++; > + goto done_unlock; > exit_free: > - spin_unlock(&ioasid_allocator_lock); > kfree(data); > - return INVALID_IOASID; > +done_unlock: > + spin_unlock(&ioasid_allocator_lock); > + return id; > } > EXPORT_SYMBOL_GPL(ioasid_alloc); > > -/** > - * ioasid_free - Free an IOASID > - * @ioasid: the ID to remove > - */ > -void ioasid_free(ioasid_t ioasid) > +static void ioasid_do_free_locked(struct ioasid_data *data) > { > struct ioasid_data *ioasid_data; > > - spin_lock(&ioasid_allocator_lock); > - ioasid_data = xa_load(&active_allocator->xa, ioasid); > - if (!ioasid_data) { > - pr_err("Trying to free unknown IOASID %u\n", ioasid); > - goto exit_unlock; > - } > - > - active_allocator->ops->free(ioasid, active_allocator->ops->pdata); > + active_allocator->ops->free(data->id, active_allocator->ops->pdata); > /* Custom allocator needs additional steps to free the xa element */ > if (active_allocator->flags & IOASID_ALLOCATOR_CUSTOM) { > - ioasid_data = xa_erase(&active_allocator->xa, ioasid); > + ioasid_data = xa_erase(&active_allocator->xa, data->id); > kfree_rcu(ioasid_data, rcu); > } > > -exit_unlock: > + data->set->nr_ioasids--; > + xa_erase(&data->set->xa, data->id); > +} > + > +static void ioasid_free_locked(struct ioasid_set *set, ioasid_t ioasid) > +{ > + struct ioasid_data *data; > + > + data = xa_load(&active_allocator->xa, ioasid); > + if (!data) { > + pr_err("Trying to free unknown IOASID %u\n", ioasid); > + return; > + } > + if (data->set != set) { > + pr_warn("Cannot free IOASID %u due to set ownership\n", ioasid); > + return; > + } > + /* Check if the set exists */ > + if (WARN_ON(!xa_load(&ioasid_sets, data->set->id))) > + return; > + > + ioasid_do_free_locked(data); > +} > + > +/** > + * ioasid_free - Drop reference on an IOASID. Free if refcount drops to 0, > + * including free from its set and system-wide list. > + * @set: The ioasid_set to check permission with. If not NULL, IOASID > + * free will fail if the set does not match. > + * @ioasid: The IOASID to remove > + */ > +void ioasid_free(struct ioasid_set *set, ioasid_t ioasid) > +{ > + spin_lock(&ioasid_allocator_lock); > + ioasid_free_locked(set, ioasid); > spin_unlock(&ioasid_allocator_lock); > } > EXPORT_SYMBOL_GPL(ioasid_free); > > +static void ioasid_set_get_locked(struct ioasid_set *set) > +{ > + if (WARN_ON(!ioasid_set_is_valid(set))) > + return; > + > + refcount_inc(&set->ref); > +} > + > +void ioasid_set_get(struct ioasid_set *set) > +{ > + spin_lock(&ioasid_allocator_lock); > + ioasid_set_get_locked(set); > + spin_unlock(&ioasid_allocator_lock); > +} > +EXPORT_SYMBOL_GPL(ioasid_set_get); > + > +static void ioasid_set_put_locked(struct ioasid_set *set) > +{ > + struct ioasid_data *entry; > + unsigned long index; > + > + if (WARN_ON(!ioasid_set_is_valid(set))) > + return; > + > + if (!refcount_dec_and_test(&set->ref)) > + return; > + > + /* The set is already empty, we just destroy the set. */ > + if (xa_empty(&set->xa)) > + goto done_destroy; Do we need this optimization, if xa_for_each() is allowed on the empty xa? This function doesn't really need to be fast. Otherwise you can just test nr_ioasids. > + > + /* > + * Free all PASIDs from system-wide IOASID pool, all subscribers gets > + * notified and do cleanup of their own. > + * Note that some references of the IOASIDs within the set can still > + * be held after the free call. This is OK in that the IOASIDs will be > + * marked inactive, the only operations can be done is ioasid_put. > + * No need to track IOASID set states since there is no reclaim phase. > + */ > + xa_for_each(&set->xa, index, entry) { > + ioasid_free_locked(set, index); > + /* Free from per set private pool */ > + xa_erase(&set->xa, index); > + } > + > +done_destroy: > + /* Return the quota back to system pool */ > + ioasid_capacity_avail += set->quota; > + > + /* > + * Token got released right away after the ioasid_set is freed. > + * If a new set is created immediately with the newly released token, > + * it will not allocate the same IOASIDs unless they are reclaimed. > + */ > + xa_erase(&ioasid_sets, set->id); > + kfree_rcu(set, rcu); > +} > + > +/** > + * ioasid_set_put - Drop a reference to the IOASID set. Free all IOASIDs within > + * the set if there are no more users. > + * > + * @set: The IOASID set ID to be freed > + * > + * If refcount drops to zero, all IOASIDs allocated within the set will be > + * freed. > + */ > +void ioasid_set_put(struct ioasid_set *set) > +{ > + spin_lock(&ioasid_allocator_lock); > + ioasid_set_put_locked(set); > + spin_unlock(&ioasid_allocator_lock); > +} > +EXPORT_SYMBOL_GPL(ioasid_set_put); > + > /** > * ioasid_find - Find IOASID data > * @set: the IOASID set > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h > index 7fc320656be2..1ae213b660f0 100644 > --- a/include/linux/ioasid.h > +++ b/include/linux/ioasid.h > @@ -4,14 +4,43 @@ > > #include > #include > +#include > +#include > > #define INVALID_IOASID ((ioasid_t)-1) > typedef unsigned int ioasid_t; > typedef ioasid_t (*ioasid_alloc_fn_t)(ioasid_t min, ioasid_t max, void *data); > typedef void (*ioasid_free_fn_t)(ioasid_t ioasid, void *data); > > +/* IOASID set types */ > +enum ioasid_set_type { > + IOASID_SET_TYPE_NULL = 1, /* Set token is NULL */ > + IOASID_SET_TYPE_MM, /* Set token is a mm_struct pointer > + * i.e. associated with a process > + */ > + IOASID_SET_TYPE_NR, > +}; > + > +/** > + * struct ioasid_set - Meta data about ioasid_set > + * @xa: XArray to store ioasid_set private IDs, can be used for > + * guest-host IOASID mapping, or just a private IOASID namespace. > + * @token: Unique to identify an IOASID set > + * @type: Token types > + * @quota: Max number of IOASIDs can be allocated within the set > + * @nr_ioasids: Number of IOASIDs currently allocated in the set > + * @id: ID of the set > + * @ref: Reference count of the users > + */ > struct ioasid_set { > - int dummy; > + struct xarray xa; > + void *token; > + int type; Could be an 'enum ioasid_set_type' > + int quota; > + int nr_ioasids; These could be unsigned, or ioasid_t > + int id; unsigned as well > + refcount_t ref; > + struct rcu_head rcu; > }; > > /** > @@ -29,14 +58,16 @@ struct ioasid_allocator_ops { > void *pdata; > }; > > -#define DECLARE_IOASID_SET(name) struct ioasid_set name = { 0 } > - > #if IS_ENABLED(CONFIG_IOASID) > void ioasid_install_capacity(ioasid_t total); > ioasid_t ioasid_get_capacity(void); > +struct ioasid_set *ioasid_set_alloc(void *token, ioasid_t quota, int type); > +void ioasid_set_get(struct ioasid_set *set); > +void ioasid_set_put(struct ioasid_set *set); > + > ioasid_t ioasid_alloc(struct ioasid_set *set, ioasid_t min, ioasid_t max, > void *private); > -void ioasid_free(ioasid_t ioasid); > +void ioasid_free(struct ioasid_set *set, 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); > @@ -59,12 +90,20 @@ 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_free(struct ioasid_set *set, ioasid_t ioasid) > +{ > +} > + > +static inline struct ioasid_set *ioasid_set_alloc(void *token, ioasid_t quota, int type) > +{ > + return ERR_PTR(-ENOTSUPP); > +} > + > +static inline void ioasid_set_put(struct ioasid_set *set) > { > } A stub is missing for ioasid_set_get() > > -static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid, > - bool (*getter)(void *)) > +static inline void *ioasid_find(struct ioasid_set *set, ioasid_t ioasid, bool (*getter)(void *)) Spurious change? Thanks, Jean > { > return NULL; > } > -- > 2.7.4 >