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da995d538d
This is done by adding a zpci_hot_reset_device() call which does a low level reset of the PCI function without changing its higher level function state. This way it can be used while the zPCI function is bound to a driver and with DMA tables being controlled either through the IOMMU or DMA APIs which is prohibited when using zpci_disable_device() as that drop existing DMA translations. As this reset, unlike a normal FLR, also calls zpci_clear_irq() we need to implement arch_restore_msi_irqs() and make sure we re-enable IRQs for the PCI function if they were previously disabled. Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
123 lines
3.0 KiB
C
123 lines
3.0 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 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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int rc;
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if (zdev->state != ZPCI_FN_STATE_STANDBY)
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return -EIO;
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rc = sclp_pci_configure(zdev->fid);
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zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
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if (rc)
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return rc;
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zdev->state = ZPCI_FN_STATE_CONFIGURED;
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return zpci_scan_configured_device(zdev, zdev->fh);
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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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if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
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return -EIO;
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pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
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if (pdev && pci_num_vf(pdev)) {
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pci_dev_put(pdev);
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return -EBUSY;
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}
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pci_dev_put(pdev);
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return zpci_deconfigure_device(zdev);
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}
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static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
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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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if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
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return -EIO;
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/*
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* We can't take the zdev->lock as reset_slot may be called during
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* probing and/or device removal which already happens under the
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* zdev->lock. Instead the user should use the higher level
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* pci_reset_function() or pci_bus_reset() which hold the PCI device
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* lock preventing concurrent removal. If not using these functions
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* holding the PCI device lock is required.
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*/
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/* As long as the function is configured we can reset */
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if (probe)
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return 0;
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return zpci_hot_reset_device(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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*value = zpci_is_device_configured(zdev) ? 1 : 0;
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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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.reset_slot = reset_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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zdev->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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