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;
Date:   Wed, 22 Jun 2022 09:46:38 -0700
From:   Ira Weiny <ira.weiny@intel.com>
To:     Bjorn Helgaas <helgaas@kernel.org>
CC:     Dan Williams <dan.j.williams@intel.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        "Alison Schofield" <alison.schofield@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Ben Widawsky <bwidawsk@kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-cxl@vger.kernel.org>,
        <linux-pci@vger.kernel.org>
Subject: Re: [PATCH V11 3/8] PCI: Create PCI library functions in support of
 DOE mailboxes.
Message-ID: <YrNHbhGKs9DDMnm2@iweiny-desk3>
References: <20220617224019.GA1208614@bhelgaas>
 <20220618163927.GA1235355@bhelgaas>
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
In-Reply-To: <20220618163927.GA1235355@bhelgaas>
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?wVy3GUyV351dRDiAehwPdSPXY/PI9aY0mQygJK79xKbrmMZThccOCU14TpcR?=
 =?us-ascii?Q?LF9RB51DNnn+o+uIvfGmY9/12IkZXIwJZGNp5j8Rv0Vs1U/18bMeQErjXESp?=
 =?us-ascii?Q?ADi7TkThLCSz7A3SVoI0HaTeF7lss+zH7QEF67cpLLnMZM2b6q1Bkh3NT5OU?=
 =?us-ascii?Q?t6NVYFneatJL1cC1xvRpg0z13AFahwLu+eHTrBtVBTUgey79l3ECUP/BF3Wm?=
 =?us-ascii?Q?2s0UJgsjzlUpIbPHlQ8taXItxqebxqr0lca/BIGh2PSIZhh0g9QjfdwXxclC?=
 =?us-ascii?Q?obDQWEXoSzb9R8VX29PsGIYfVKdFgPK/61ZrAH4CCDIQ4zATuVBvbd4BMazb?=
 =?us-ascii?Q?AoTI8K+oljECTW4P738Fvgykg2Ue0SNDC3aYgwcptry+Mx6+EBHVTomzzFN1?=
 =?us-ascii?Q?6XN7upj46+E+ujgGCSgoSXrGebecs6vsqE1FgkuI6UdcPRELqKDf9AWrphR0?=
 =?us-ascii?Q?sag4t+76SQxXj4WbH+NKnGcQBTT3Ktla/GGEr5U/cbQz3A1sOAqz8DQjYYMq?=
 =?us-ascii?Q?vMtUoprinxQMZImrkiL5cDvNQmrsD7Nvv6uuCU37IHyTLhAXZ7zJ64A6Ngxm?=
 =?us-ascii?Q?CvkQAXjE6ldicYO4LXoRqfJF224R9D+Q0WMMFkufmgBqXWByyPZIyHHzJspH?=
 =?us-ascii?Q?wPlxON9XTXyXos5n0PuIQ4WolPFimWJkorvNfrLgRtlDXFpbrF5c0KIML9Zx?=
 =?us-ascii?Q?K5B9vPZbyEYt/woBgFwU55vlXoMGiZ1FSRYAlQJWSA3K05BEcInbR/ee/YWF?=
 =?us-ascii?Q?KvK1nGCS/wdNAvL7YdtjRvXpql4/PRIYAsXG7oW2zEUxOOmoNwteRurABFuE?=
 =?us-ascii?Q?i60V4pt6V2c5Z5sGyhXJ+YRLEhdiwpbxJbcyJY+mA22n2DgQ8gfZOsTEyWxk?=
 =?us-ascii?Q?Ve4dsJE1yfFJ0fXEN5BCJAG8Pjve17PByf4iWOreQV0A8dn6RuBW7VLvn6yy?=
 =?us-ascii?Q?4mNhotcSYI6yfqC12Wz/uj9UnuMwNEZWZgi85Q4KcPJ7A8LSrl8ZjrOoFmaS?=
 =?us-ascii?Q?f0Mzhwo9J9B1vGJ1eEE2c3K8JbmYM8V7zeobLHeN1BHYeYqCPVZN3JCJVSh6?=
 =?us-ascii?Q?ex+sy5RvBLawH5+bdAwJRIZSFIwpE5iwBFbetuIA1UUyUeGkDA9u+UCHr8VO?=
 =?us-ascii?Q?FNHVLOu7UqZxd/JC7m01IsajFlxKTxreULINYqXKqk/YEI3N0rG6k4gvQTbt?=
 =?us-ascii?Q?ty07kMXZ3lK4PzsWPKXPm/PuSVuqVI7Uh3OWRlBEk9mDkh5kft/qAcexd4Zz?=
 =?us-ascii?Q?ErBcTTlWWgMnpBpBU/j4I+cD5HCkn5g4jzQWiVvjBXkrHXRqKJu4nMA0U+UG?=
 =?us-ascii?Q?Ml9JwaQnR9RPuX07H7cUSKP8LP8F/aLTMezfQY0+zkWdW5yjJYXxKj+G81Mu?=
 =?us-ascii?Q?PfTpFgqDCwiNkzdrIXa41xD2oEjhSf7hOKWMqoiM7tfOkctKKekhqIX8gOlR?=
 =?us-ascii?Q?o3prSLs3505vQDAiY+FDhp8565JWgNQ611XiLZ8IVUjM0yODw2yGIQKhlbZo?=
 =?us-ascii?Q?A9xY/8XwL1ke6BPehfxXc9sdmTzEvuqFiTJC9XY5Q/bX4Pjy3S95ynIVtXlP?=
 =?us-ascii?Q?g74Z8hPfWwiOFEbvhm7OHRX9WQqB/u9yhjcmoL32+hXLI8tkULF3OMmVpD+0?=
 =?us-ascii?Q?tqjbsk8N34m2CExNZ1UEgecsnS7m7Lb6khIroKT9OUTNFeEHcA80apHmyfxr?=
 =?us-ascii?Q?U3qc8bPoamvQgqnlvtDhTzyCNlnEE89khVXIc9pJ0lA3J3ASo6jkDTCLbVkm?=
 =?us-ascii?Q?fWVpKQ6nLd/jAFqlq4j0AYIDDioLWfA=3D?=
X-MS-Exchange-CrossTenant-Network-Message-Id: c03d6170-8255-46e1-efc8-08da546ec948
X-MS-Exchange-CrossTenant-AuthSource: DM4PR11MB6311.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Jun 2022 16:46:42.7576
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: Azin8Cyp5e6oaNYNPHTz7HRCbYlkQbNybXd8TqArhEgZoNF2LrnAI2fZGPVYXJ0hdh+6FjsTilpD+TuNGleYvg==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR11MB5755
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=-5.0 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,
        DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,
        SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sat, Jun 18, 2022 at 11:39:27AM -0500, Bjorn Helgaas wrote:
> On Fri, Jun 17, 2022 at 05:40:19PM -0500, Bjorn Helgaas wrote:
> > On Fri, Jun 10, 2022 at 01:22:54PM -0700, ira.weiny@intel.com wrote:
> > > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > > 
> > > Introduced in a PCI r6.0, sec 6.30, DOE provides a config space based
> > > mailbox with standard protocol discovery.  Each mailbox is accessed
> > > through a DOE Extended Capability.
> 
> > > + * pci_doe_get_irq_num() - Return the irq number for the mailbox at offset
> > > + *
> > > + * @pdev: The PCI device
> > > + * @offset: Offset of the DOE mailbox
> > > + *
> > > + * Returns: irq number on success
> > > + *	    -errno if irqs are not supported on this mailbox
> > > + */
> > > +int pci_doe_get_irq_num(struct pci_dev *pdev, int offset)
> > > +{
> > > +	u32 val;
> > > +
> > > +	pci_read_config_dword(pdev, offset + PCI_DOE_CAP, &val);
> > > +	if (!FIELD_GET(PCI_DOE_CAP_INT, val))
> > > +		return -EOPNOTSUPP;
> > > +
> > > +	return FIELD_GET(PCI_DOE_CAP_IRQ, val);
> > > +}
> > > +EXPORT_SYMBOL_GPL(pci_doe_get_irq_num);
> > 
> > Confusing function name (and comment) since PCI_DOE_CAP_IRQ is an
> > Interrupt Message Number that has nothing to do with Linux IRQ
> > numbers.
> > 
> > I see we already have PCI_EXP_FLAGS_IRQ, PCI_ERR_ROOT_AER_IRQ,
> > PCI_EXP_DPC_IRQ, so I guess you're in good company.
> 
> Should have been more clear about this: I think we should rename the
> new one to be PCI_DOE_CAP_INT_MSG_NUM or similar, and rename the
> function as well.  It's too confusing to use "irq" for both Linux IRQs
> and what the spec calls "Interupt Message Numbers".

Oh...  ok I was thinking of using int_msg_num in the function and variable
names.  I was just not sure about 'int'.  But if you like it then I do too!
:-D

I'll update the code as well as that macro.

Thanks again!
Ira