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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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05bc1be6db
The zPCI bus is in charge to handle common zPCI resources for zPCI devices. Creating the zPCI bus, the PCI bus, the zPCI devices and the PCI devices and hotplug slots done in a specific order: - PCI hotplug slot creation needs a PCI bus - PCI bus needs a PCI domain which is reported by the pci_domain_nr() when setting up the host bridge - PCI domain is set from the zPCI with devfn 0 this is necessary to have a reproducible enumeration Therefore we can not create devices or hotplug slots for any PCI device associated with a zPCI device before having discovered the function zero of the bus. The discovery and initialization of devices can be done at several points in the code: - On Events, serialized in a thread context - On initialization, in the kernel init thread context - When powering on the hotplug slot, in a user thread context The removal of devices and their parent bus may also be done on events or for devices when powering down the slot. To guarantee the existence of the bus and devices until they are no more needed we use kref in zPCI bus and introduce a reference count in the zPCI devices. In this patch the zPCI bus still only accept a device with a devfn 0. Signed-off-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
151 lines
3.1 KiB
C
151 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* PCI Hot Plug Controller Driver for System z
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*
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* Copyright 2012 IBM Corp.
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*
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* Author(s):
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* Jan Glauber <jang@linux.vnet.ibm.com>
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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/pci.h>
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#include <linux/pci_hotplug.h>
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#include <asm/pci_debug.h>
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#include <asm/sclp.h>
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#define SLOT_NAME_SIZE 10
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static int zpci_fn_configured(enum zpci_state state)
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{
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return state == ZPCI_FN_STATE_CONFIGURED ||
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state == ZPCI_FN_STATE_ONLINE;
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}
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static inline int zdev_configure(struct zpci_dev *zdev)
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{
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int ret = sclp_pci_configure(zdev->fid);
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zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, ret);
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if (!ret)
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zdev->state = ZPCI_FN_STATE_CONFIGURED;
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return ret;
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}
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static inline int zdev_deconfigure(struct zpci_dev *zdev)
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{
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int ret = sclp_pci_deconfigure(zdev->fid);
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zpci_dbg(3, "deconf fid:%x, rc:%d\n", zdev->fid, ret);
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if (!ret)
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zdev->state = ZPCI_FN_STATE_STANDBY;
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return ret;
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}
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static int enable_slot(struct hotplug_slot *hotplug_slot)
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{
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struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
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hotplug_slot);
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struct zpci_bus *zbus = zdev->zbus;
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int rc;
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if (zdev->state != ZPCI_FN_STATE_STANDBY)
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return -EIO;
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rc = zdev_configure(zdev);
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if (rc)
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return rc;
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rc = zpci_enable_device(zdev);
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if (rc)
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goto out_deconfigure;
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pci_scan_slot(zbus->bus, ZPCI_DEVFN);
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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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return rc;
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out_deconfigure:
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zdev_deconfigure(zdev);
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return rc;
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}
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static int disable_slot(struct hotplug_slot *hotplug_slot)
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{
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struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
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hotplug_slot);
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struct pci_dev *pdev;
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struct zpci_bus *zbus = zdev->zbus;
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int rc;
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if (!zpci_fn_configured(zdev->state))
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return -EIO;
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pdev = pci_get_slot(zbus->bus, ZPCI_DEVFN);
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if (pdev) {
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pci_stop_and_remove_bus_device_locked(pdev);
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pci_dev_put(pdev);
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}
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rc = zpci_disable_device(zdev);
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if (rc)
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return rc;
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return zdev_deconfigure(zdev);
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}
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static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
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hotplug_slot);
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switch (zdev->state) {
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case ZPCI_FN_STATE_STANDBY:
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*value = 0;
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break;
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default:
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*value = 1;
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break;
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}
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return 0;
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}
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static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
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{
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/* if the slot exits it always contains a function */
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*value = 1;
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return 0;
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}
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static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
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.enable_slot = enable_slot,
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.disable_slot = disable_slot,
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.get_power_status = get_power_status,
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.get_adapter_status = get_adapter_status,
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};
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int zpci_init_slot(struct zpci_dev *zdev)
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{
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char name[SLOT_NAME_SIZE];
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struct zpci_bus *zbus = zdev->zbus;
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zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
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snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
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return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
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ZPCI_DEVFN, name);
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}
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void zpci_exit_slot(struct zpci_dev *zdev)
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{
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pci_hp_deregister(&zdev->hotplug_slot);
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}
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