Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Thomas Gleixner <tglx@linutronix.de>
To:     "Tian, Kevin" <kevin.tian@intel.com>,
        LKML <linux-kernel@vger.kernel.org>
Cc:     "x86@kernel.org" <x86@kernel.org>, Joerg Roedel <joro@8bytes.org>,
        Will Deacon <will@kernel.org>,
        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Marc Zyngier <maz@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jason Gunthorpe <jgg@mellanox.com>,
        "Jiang, Dave" <dave.jiang@intel.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        "Williams, Dan J" <dan.j.williams@intel.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        "Raj, Ashok" <ashok.raj@intel.com>, Jon Mason <jdmason@kudzu.us>,
        Allen Hubbe <allenbh@gmail.com>,
        "Ahmed S. Darwish" <darwi@linutronix.de>,
        "Chatre, Reinette" <reinette.chatre@intel.com>
Subject: RE: [patch 08/20] genirq/msi: Make MSI descriptor iterators device
 domain aware
In-Reply-To: <BN9PR11MB5276F39FAC20C32E273B7FB48C099@BN9PR11MB5276.namprd11.prod.outlook.com>
References: <20221111131813.914374272@linutronix.de>
 <20221111132706.500733944@linutronix.de>
 <BN9PR11MB5276F39FAC20C32E273B7FB48C099@BN9PR11MB5276.namprd11.prod.outlook.com>
Date:   Fri, 18 Nov 2022 13:17:04 +0100
Message-ID: <87r0y0jw3j.ffs@tglx>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Fri, Nov 18 2022 at 07:57, Kevin Tian wrote:
>> From: Thomas Gleixner <tglx@linutronix.de>
>> Sent: Friday, November 11, 2022 9:57 PM
>> 
>> +/* Invalid XA index which is outside of any searchable range */
>> +#define MSI_XA_MAX_INDEX	(ULONG_MAX - 1)
>> +#define MSI_XA_DOMAIN_SIZE	(MSI_MAX_INDEX + 1)
>> +
>
> Out of curiosity. Other places treat MSI_MAX_INDEX - 1 as the upper
> bound of a valid range. This size definition here implies that the last ID
> is wasted for every domain. Is it intended?

Bah. MSI_MAX_INDEX is inclusive so the size must be + 1. I obviously
missed that in the other places which use it as upper bound.

Not that it matters, but yes. Let me fix that.