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Thu, 5 May 2022 08:38:40 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AB7D011C04C; Thu, 5 May 2022 08:38:40 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 5 May 2022 08:38:40 +0000 (GMT) From: Niklas Schnelle To: Bjorn Helgaas , Jan Kiszka , Matthew Rosato , Pierre Morel Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-s390@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH RESEND v5 4/4] s390/pci: allow zPCI zbus without a function zero Date: Thu, 5 May 2022 10:38:39 +0200 Message-Id: <20220505083839.1315705-5-schnelle@linux.ibm.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220505083839.1315705-1-schnelle@linux.ibm.com> References: <20220505083839.1315705-1-schnelle@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: IpSXq_jPtXQ6x3HR3qPs-TFOY4OL8BO- X-Proofpoint-GUID: V6jJxyV-HUK-5mpmTHwZBSNtk5Hfm5bt X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.858,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-05_02,2022-05-04_02,2022-02-23_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 bulkscore=0 priorityscore=1501 mlxscore=0 lowpriorityscore=0 phishscore=0 clxscore=1015 mlxlogscore=940 malwarescore=0 spamscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000 definitions=main-2205050055 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Currently the zPCI code block PCI bus creation and probing of a zPCI zbus unless there is a PCI function with devfn 0. This is always the case for the PCI functions with hidden RID but may keep PCI functions from a multi-function PCI device with RID information invisible until the function 0 becomes visible. Worse as a PCI bus is necessary to even present a PCI hotplug slot even that remains invisible. With the probing of these so called isolated PCI functions enabled for s390 in common code this restriction is no longer necessary. On network cards with multiple ports and a PF per port this also allows using each port on its own while still providing the physical PCI topology information in the devfn needed to associate VFs with their parent PF. Signed-off-by: Niklas Schnelle --- arch/s390/pci/pci_bus.c | 82 ++++++++++------------------------------- 1 file changed, 20 insertions(+), 62 deletions(-) diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c index 5d77acbd1c87..6a8da1b742ae 100644 --- a/arch/s390/pci/pci_bus.c +++ b/arch/s390/pci/pci_bus.c @@ -145,9 +145,6 @@ int zpci_bus_scan_bus(struct zpci_bus *zbus) struct zpci_dev *zdev; int devfn, rc, ret = 0; - if (!zbus->function[0]) - return 0; - for (devfn = 0; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { zdev = zbus->function[devfn]; if (zdev && zdev->state == ZPCI_FN_STATE_CONFIGURED) { @@ -184,26 +181,26 @@ void zpci_bus_scan_busses(void) /* zpci_bus_create_pci_bus - Create the PCI bus associated with this zbus * @zbus: the zbus holding the zdevices - * @f0: function 0 of the bus + * @fr: PCI root function that will determine the bus's domain, and bus speeed * @ops: the pci operations * - * Function zero is taken as a parameter as this is used to determine the - * domain, multifunction property and maximum bus speed of the entire bus. + * The PCI function @fr determines the domain (its UID), multifunction property + * and maximum bus speed of the entire bus. * * Return: 0 on success, an error code otherwise */ -static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *f0, struct pci_ops *ops) +static int zpci_bus_create_pci_bus(struct zpci_bus *zbus, struct zpci_dev *fr, struct pci_ops *ops) { struct pci_bus *bus; int domain; - domain = zpci_alloc_domain((u16)f0->uid); + domain = zpci_alloc_domain((u16)fr->uid); if (domain < 0) return domain; zbus->domain_nr = domain; - zbus->multifunction = f0->rid_available; - zbus->max_bus_speed = f0->max_bus_speed; + zbus->multifunction = fr->rid_available; + zbus->max_bus_speed = fr->max_bus_speed; /* * Note that the zbus->resources are taken over and zbus->resources @@ -303,47 +300,6 @@ void pcibios_bus_add_device(struct pci_dev *pdev) } } -/* zpci_bus_create_hotplug_slots - Add hotplug slot(s) for device added to bus - * @zdev: the zPCI device that was newly added - * - * Add the hotplug slot(s) for the newly added PCI function. Normally this is - * simply the slot for the function itself. If however we are adding the - * function 0 on a zbus, it might be that we already registered functions on - * that zbus but could not create their hotplug slots yet so add those now too. - * - * Return: 0 on success, an error code otherwise - */ -static int zpci_bus_create_hotplug_slots(struct zpci_dev *zdev) -{ - struct zpci_bus *zbus = zdev->zbus; - int devfn, rc = 0; - - rc = zpci_init_slot(zdev); - if (rc) - return rc; - zdev->has_hp_slot = 1; - - if (zdev->devfn == 0 && zbus->multifunction) { - /* Now that function 0 is there we can finally create the - * hotplug slots for those functions with devfn != 0 that have - * been parked in zbus->function[] waiting for us to be able to - * create the PCI bus. - */ - for (devfn = 1; devfn < ZPCI_FUNCTIONS_PER_BUS; devfn++) { - zdev = zbus->function[devfn]; - if (zdev && !zdev->has_hp_slot) { - rc = zpci_init_slot(zdev); - if (rc) - return rc; - zdev->has_hp_slot = 1; - } - } - - } - - return rc; -} - static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) { int rc = -EINVAL; @@ -352,21 +308,19 @@ static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev) pr_err("devfn %04x is already assigned\n", zdev->devfn); return rc; } + zdev->zbus = zbus; zbus->function[zdev->devfn] = zdev; zpci_nb_devices++; - if (zbus->bus) { - if (zbus->multifunction && !zdev->rid_available) { - WARN_ONCE(1, "rid_available not set for multifunction\n"); - goto error; - } - - zpci_bus_create_hotplug_slots(zdev); - } else { - /* Hotplug slot will be created once function 0 appears */ - zbus->multifunction = 1; + if (zbus->multifunction && !zdev->rid_available) { + WARN_ONCE(1, "rid_available not set for multifunction\n"); + goto error; } + rc = zpci_init_slot(zdev); + if (rc) + goto error; + zdev->has_hp_slot = 1; return 0; @@ -400,7 +354,11 @@ int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops) return -ENOMEM; } - if (zdev->devfn == 0) { + if (!zbus->bus) { + /* The UID of the first PCI function registered with a zpci_bus + * is used as the domain number for that bus. Currently there + * is exactly one zpci_bus per domain. + */ rc = zpci_bus_create_pci_bus(zbus, zdev, ops); if (rc) goto error;