mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-15 05:26:42 +07:00
b97bf44f99
Currently there are four places in which a PCI function is scanned and made available to drivers: 1. In pci_scan_root_bus() as part of the initial zbus creation. 2. In zpci_bus_add_devices() when registering a device in configured state on a zbus that has already been scanned. 3. When a function is already known to zPCI (in reserved/standby state) and configuration is triggered through firmware by PEC 0x301. 4. When a device is already known to zPCI (in standby/reserved state) and configuration is triggered from within Linux using enable_slot(). The PF/VF linking step and setting of pdev->is_virtfn introduced with commite5794cf1a2
("s390/pci: create links between PFs and VFs") was only triggered for the second case, which is where VFs created through sriov_numvfs usually land. However unlike some other platforms but like POWER VFs can be individually enabled/disabled through /sys/bus/pci/slots. Fix this by doing VF setup as part of pcibios_bus_add_device() which is called in all of the above cases. Finally to remove the PF/VF links call the common code pci_iov_remove_virtfn() function to remove linked VFs. This takes care of the necessary sysfs cleanup. Fixes:e5794cf1a2
("s390/pci: create links between PFs and VFs") Cc: <stable@vger.kernel.org> # 5.8:2f0230b2f2
: s390/pci: re-introduce zpci_remove_device() Cc: <stable@vger.kernel.org> # 5.8 Acked-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
337 lines
7.2 KiB
C
337 lines
7.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 2020
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*
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* Author(s):
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* Pierre Morel <pmorel@linux.ibm.com>
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*
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*/
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#define KMSG_COMPONENT "zpci"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/export.h>
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#include <linux/delay.h>
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#include <linux/seq_file.h>
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#include <linux/jump_label.h>
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#include <linux/pci.h>
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#include <linux/printk.h>
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#include <asm/pci_clp.h>
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#include <asm/pci_dma.h>
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#include "pci_bus.h"
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static LIST_HEAD(zbus_list);
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static DEFINE_SPINLOCK(zbus_list_lock);
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static int zpci_nb_devices;
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/* zpci_bus_scan
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* @zbus: the zbus holding the zdevices
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* @ops: the pci operations
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*
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* The domain number must be set before pci_scan_root_bus is called.
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* This function can be called once the domain is known, hence
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* when the function_0 is dicovered.
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*/
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static int zpci_bus_scan(struct zpci_bus *zbus, int domain, struct pci_ops *ops)
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{
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struct pci_bus *bus;
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int rc;
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rc = zpci_alloc_domain(domain);
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if (rc < 0)
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return rc;
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zbus->domain_nr = rc;
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bus = pci_scan_root_bus(NULL, ZPCI_BUS_NR, ops, zbus, &zbus->resources);
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if (!bus) {
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zpci_free_domain(zbus->domain_nr);
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return -EFAULT;
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}
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zbus->bus = bus;
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pci_bus_add_devices(bus);
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return 0;
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}
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static void zpci_bus_release(struct kref *kref)
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{
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struct zpci_bus *zbus = container_of(kref, struct zpci_bus, kref);
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if (zbus->bus) {
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pci_lock_rescan_remove();
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pci_stop_root_bus(zbus->bus);
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zpci_free_domain(zbus->domain_nr);
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pci_free_resource_list(&zbus->resources);
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pci_remove_root_bus(zbus->bus);
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pci_unlock_rescan_remove();
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}
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spin_lock(&zbus_list_lock);
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list_del(&zbus->bus_next);
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spin_unlock(&zbus_list_lock);
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kfree(zbus);
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}
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static void zpci_bus_put(struct zpci_bus *zbus)
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{
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kref_put(&zbus->kref, zpci_bus_release);
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}
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static struct zpci_bus *zpci_bus_get(int pchid)
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{
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struct zpci_bus *zbus;
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spin_lock(&zbus_list_lock);
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list_for_each_entry(zbus, &zbus_list, bus_next) {
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if (pchid == zbus->pchid) {
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kref_get(&zbus->kref);
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goto out_unlock;
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}
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}
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zbus = NULL;
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out_unlock:
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spin_unlock(&zbus_list_lock);
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return zbus;
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}
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static struct zpci_bus *zpci_bus_alloc(int pchid)
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{
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struct zpci_bus *zbus;
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zbus = kzalloc(sizeof(*zbus), GFP_KERNEL);
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if (!zbus)
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return NULL;
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zbus->pchid = pchid;
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INIT_LIST_HEAD(&zbus->bus_next);
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spin_lock(&zbus_list_lock);
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list_add_tail(&zbus->bus_next, &zbus_list);
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spin_unlock(&zbus_list_lock);
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kref_init(&zbus->kref);
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INIT_LIST_HEAD(&zbus->resources);
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zbus->bus_resource.start = 0;
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zbus->bus_resource.end = ZPCI_BUS_NR;
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zbus->bus_resource.flags = IORESOURCE_BUS;
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pci_add_resource(&zbus->resources, &zbus->bus_resource);
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return zbus;
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}
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#ifdef CONFIG_PCI_IOV
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static int zpci_bus_link_virtfn(struct pci_dev *pdev,
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struct pci_dev *virtfn, int vfid)
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{
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int rc;
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rc = pci_iov_sysfs_link(pdev, virtfn, vfid);
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if (rc)
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return rc;
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virtfn->is_virtfn = 1;
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virtfn->multifunction = 0;
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virtfn->physfn = pci_dev_get(pdev);
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return 0;
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}
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static int zpci_bus_setup_virtfn(struct zpci_bus *zbus,
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struct pci_dev *virtfn, int vfn)
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{
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int i, cand_devfn;
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struct zpci_dev *zdev;
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struct pci_dev *pdev;
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int vfid = vfn - 1; /* Linux' vfid's start at 0 vfn at 1*/
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int rc = 0;
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if (!zbus->multifunction)
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return 0;
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/* If the parent PF for the given VF is also configured in the
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* instance, it must be on the same zbus.
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* We can then identify the parent PF by checking what
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* devfn the VF would have if it belonged to that PF using the PF's
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* stride and offset. Only if this candidate devfn matches the
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* actual devfn will we link both functions.
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*/
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for (i = 0; i < ZPCI_FUNCTIONS_PER_BUS; i++) {
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zdev = zbus->function[i];
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if (zdev && zdev->is_physfn) {
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pdev = pci_get_slot(zbus->bus, zdev->devfn);
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if (!pdev)
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continue;
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cand_devfn = pci_iov_virtfn_devfn(pdev, vfid);
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if (cand_devfn == virtfn->devfn) {
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rc = zpci_bus_link_virtfn(pdev, virtfn, vfid);
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/* balance pci_get_slot() */
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pci_dev_put(pdev);
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break;
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}
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/* balance pci_get_slot() */
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pci_dev_put(pdev);
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}
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}
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return rc;
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}
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#else
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static inline int zpci_bus_setup_virtfn(struct zpci_bus *zbus,
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struct pci_dev *virtfn, int vfn)
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{
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return 0;
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}
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#endif
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void pcibios_bus_add_device(struct pci_dev *pdev)
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{
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struct zpci_dev *zdev = to_zpci(pdev);
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/*
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* With pdev->no_vf_scan the common PCI probing code does not
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* perform PF/VF linking.
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*/
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if (zdev->vfn)
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zpci_bus_setup_virtfn(zdev->zbus, pdev, zdev->vfn);
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}
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static int zpci_bus_add_device(struct zpci_bus *zbus, struct zpci_dev *zdev)
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{
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struct pci_bus *bus;
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struct resource_entry *window, *n;
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struct resource *res;
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struct pci_dev *pdev;
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int rc;
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bus = zbus->bus;
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if (!bus)
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return -EINVAL;
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pdev = pci_get_slot(bus, zdev->devfn);
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if (pdev) {
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/* Device is already known. */
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pci_dev_put(pdev);
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return 0;
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}
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rc = zpci_init_slot(zdev);
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if (rc)
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return rc;
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zdev->has_hp_slot = 1;
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resource_list_for_each_entry_safe(window, n, &zbus->resources) {
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res = window->res;
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pci_bus_add_resource(bus, res, 0);
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}
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pdev = pci_scan_single_device(bus, zdev->devfn);
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if (pdev)
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pci_bus_add_device(pdev);
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return 0;
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}
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static void zpci_bus_add_devices(struct zpci_bus *zbus)
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{
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int i;
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for (i = 1; i < ZPCI_FUNCTIONS_PER_BUS; i++)
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if (zbus->function[i])
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zpci_bus_add_device(zbus, zbus->function[i]);
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pci_lock_rescan_remove();
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pci_bus_add_devices(zbus->bus);
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pci_unlock_rescan_remove();
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}
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int zpci_bus_device_register(struct zpci_dev *zdev, struct pci_ops *ops)
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{
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struct zpci_bus *zbus = NULL;
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int rc = -EBADF;
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if (zpci_nb_devices == ZPCI_NR_DEVICES) {
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pr_warn("Adding PCI function %08x failed because the configured limit of %d is reached\n",
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zdev->fid, ZPCI_NR_DEVICES);
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return -ENOSPC;
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}
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zpci_nb_devices++;
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if (zdev->devfn >= ZPCI_FUNCTIONS_PER_BUS)
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return -EINVAL;
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if (!s390_pci_no_rid && zdev->rid_available)
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zbus = zpci_bus_get(zdev->pchid);
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if (!zbus) {
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zbus = zpci_bus_alloc(zdev->pchid);
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if (!zbus)
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return -ENOMEM;
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}
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zdev->zbus = zbus;
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if (zbus->function[zdev->devfn]) {
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pr_err("devfn %04x is already assigned\n", zdev->devfn);
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goto error; /* rc already set */
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}
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zbus->function[zdev->devfn] = zdev;
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zpci_setup_bus_resources(zdev, &zbus->resources);
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if (zbus->bus) {
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if (!zbus->multifunction) {
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WARN_ONCE(1, "zbus is not multifunction\n");
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goto error_bus;
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}
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if (!zdev->rid_available) {
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WARN_ONCE(1, "rid_available not set for multifunction\n");
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goto error_bus;
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}
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rc = zpci_bus_add_device(zbus, zdev);
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if (rc)
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goto error_bus;
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} else if (zdev->devfn == 0) {
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if (zbus->multifunction && !zdev->rid_available) {
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WARN_ONCE(1, "rid_available not set on function 0 for multifunction\n");
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goto error_bus;
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}
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rc = zpci_bus_scan(zbus, (u16)zdev->uid, ops);
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if (rc)
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goto error_bus;
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zpci_bus_add_devices(zbus);
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rc = zpci_init_slot(zdev);
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if (rc)
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goto error_bus;
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zdev->has_hp_slot = 1;
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zbus->multifunction = zdev->rid_available;
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zbus->max_bus_speed = zdev->max_bus_speed;
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} else {
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zbus->multifunction = 1;
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}
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return 0;
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error_bus:
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zpci_nb_devices--;
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zbus->function[zdev->devfn] = NULL;
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error:
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pr_err("Adding PCI function %08x failed\n", zdev->fid);
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zpci_bus_put(zbus);
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return rc;
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}
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void zpci_bus_device_unregister(struct zpci_dev *zdev)
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{
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struct zpci_bus *zbus = zdev->zbus;
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zpci_nb_devices--;
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zbus->function[zdev->devfn] = NULL;
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zpci_bus_put(zbus);
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}
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