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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham 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 C5D2CC43331 for ; Fri, 27 Mar 2020 16:02:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A784920737 for ; Fri, 27 Mar 2020 16:02:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727749AbgC0QCQ (ORCPT ); Fri, 27 Mar 2020 12:02:16 -0400 Received: from mga02.intel.com ([134.134.136.20]:31389 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726333AbgC0QCQ (ORCPT ); Fri, 27 Mar 2020 12:02:16 -0400 IronPort-SDR: hKCHUVvVwrKIlBFV4QH7qB2q7IYJbTKVtua7rSbnB92WFJcExbBTiO7E57dvFO8jpMLGrtSNgB ibm9L/bcSp9w== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2020 09:02:15 -0700 IronPort-SDR: xB2dVmSGKpWZumoZA4tldw1y68F80iVE6l1Sl7XNuAGzMoP4bmWRqTu/z4QoAm8CunjOIQYfNK rajAc6vD70+w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,313,1580803200"; d="scan'208";a="247925019" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga003.jf.intel.com with ESMTP; 27 Mar 2020 09:02:15 -0700 Date: Fri, 27 Mar 2020 09:08:00 -0700 From: Jacob Pan To: "Tian, Kevin" Cc: Joerg Roedel , Alex Williamson , Lu Baolu , "iommu@lists.linux-foundation.org" , LKML , David Woodhouse , Jean-Philippe Brucker , "Liu, Yi L" , "Raj, Ashok" , Christoph Hellwig , Jonathan Cameron , Eric Auger , jacob.jun.pan@linux.intel.com Subject: Re: [PATCH 01/10] iommu/ioasid: Introduce system-wide capacity Message-ID: <20200327090800.64949170@jacob-builder> In-Reply-To: References: <1585158931-1825-1-git-send-email-jacob.jun.pan@linux.intel.com> <1585158931-1825-2-git-send-email-jacob.jun.pan@linux.intel.com> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 27 Mar 2020 08:07:20 +0000 "Tian, Kevin" wrote: > > From: Jacob Pan > > Sent: Thursday, March 26, 2020 1:55 AM > > > > IOASID is a limited system-wide resource that can be allocated at > > runtime. This limitation can be enumerated during boot. For > > example, on x86 platforms, PCI Process Address Space ID (PASID) > > allocation uses IOASID service. The number of supported PASID bits > > are enumerated by extended capability register as defined in the > > VT-d spec. > > > > This patch adds a helper to set the system capacity, it expected to > > be set during boot prior to any allocation request. > > > > Signed-off-by: Jacob Pan > > --- > > drivers/iommu/ioasid.c | 15 +++++++++++++++ > > include/linux/ioasid.h | 5 ++++- > > 2 files changed, 19 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c > > index 0f8dd377aada..4026e52855b9 100644 > > --- a/drivers/iommu/ioasid.c > > +++ b/drivers/iommu/ioasid.c > > @@ -17,6 +17,21 @@ struct ioasid_data { > > struct rcu_head rcu; > > }; > > > > +static ioasid_t ioasid_capacity; > > +static ioasid_t ioasid_capacity_avail; > > + > > +/* System capacity can only be set once */ > > +void ioasid_install_capacity(ioasid_t total) > > +{ > > + if (ioasid_capacity) { > > + pr_warn("IOASID capacity already set at %d\n", > > ioasid_capacity); > > + return; > > + } > > + > > + ioasid_capacity = ioasid_capacity_avail = total; > > +} > > +EXPORT_SYMBOL_GPL(ioasid_install_capacity); > > + > > From all the texts in this patch, looks ioasid_set_capacity might be > a better name? > That was my initial choice as well :), but it may get confused with ioasid_set. I will rephrase the text to avoid 'set'. > > /* > > * struct ioasid_allocator_data - Internal data structure to hold > > information > > * about an allocator. There are two types of allocators: > > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h > > index 6f000d7a0ddc..9711fa0dc357 100644 > > --- a/include/linux/ioasid.h > > +++ b/include/linux/ioasid.h > > @@ -40,7 +40,7 @@ void *ioasid_find(struct ioasid_set *set, > > ioasid_t ioasid, int ioasid_register_allocator(struct > > ioasid_allocator_ops *allocator); void > > ioasid_unregister_allocator(struct ioasid_allocator_ops > > *allocator); int ioasid_set_data(ioasid_t ioasid, void *data); - > > +void ioasid_install_capacity(ioasid_t total); > > #else /* !CONFIG_IOASID */ > > static inline ioasid_t ioasid_alloc(struct ioasid_set *set, > > ioasid_t min, ioasid_t max, void *private) > > @@ -72,5 +72,8 @@ static inline int ioasid_set_data(ioasid_t > > ioasid, void *data) > > return -ENOTSUPP; > > } > > > > +static inline void ioasid_install_capacity(ioasid_t total) > > +{ > > +} > > #endif /* CONFIG_IOASID */ > > #endif /* __LINUX_IOASID_H */ > > -- > > 2.7.4 > [Jacob Pan]