WSL2-Linux-Kernel/drivers/pci/hotplug/pciehp_pci.c

121 строка
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* PCI Express Hot Plug Controller Driver
*
* Copyright (C) 1995,2001 Compaq Computer Corporation
* Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
* Copyright (C) 2001 IBM Corp.
* Copyright (C) 2003-2004 Intel Corporation
*
* All rights reserved.
*
* Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
*
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include "../pci.h"
#include "pciehp.h"
/**
* pciehp_configure_device() - enumerate PCI devices below a hotplug bridge
* @ctrl: PCIe hotplug controller
*
* Enumerate PCI devices below a hotplug bridge and add them to the system.
* Return 0 on success, %-EEXIST if the devices are already enumerated or
* %-ENODEV if enumeration failed.
*/
int pciehp_configure_device(struct controller *ctrl)
{
struct pci_dev *dev;
struct pci_dev *bridge = ctrl->pcie->port;
struct pci_bus *parent = bridge->subordinate;
int num, ret = 0;
pci_lock_rescan_remove();
dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
if (dev) {
/*
* The device is already there. Either configured by the
* boot firmware or a previous hotplug event.
*/
ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n",
pci_name(dev), pci_domain_nr(parent), parent->number);
pci_dev_put(dev);
ret = -EEXIST;
goto out;
}
num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
if (num == 0) {
ctrl_err(ctrl, "No new device found\n");
ret = -ENODEV;
goto out;
}
for_each_pci_bridge(dev, parent)
pci_hp_add_bridge(dev);
pci_assign_unassigned_bridge_resources(bridge);
pcie_bus_configure_settings(parent);
pci_bus_add_devices(parent);
out:
pci_unlock_rescan_remove();
return ret;
}
/**
* pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge
* @ctrl: PCIe hotplug controller
* @presence: whether the card is still present in the slot;
* true for safe removal via sysfs or an Attention Button press,
* false for surprise removal
*
* Unbind PCI devices below a hotplug bridge from their drivers and remove
* them from the system. Safely removed devices are quiesced. Surprise
* removed devices are marked as such to prevent further accesses.
*/
void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
{
struct pci_dev *dev, *temp;
struct pci_bus *parent = ctrl->pcie->port->subordinate;
u16 command;
ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
__func__, pci_domain_nr(parent), parent->number);
if (!presence)
pci_walk_bus(parent, pci_dev_set_disconnected, NULL);
pci_lock_rescan_remove();
/*
* Stopping an SR-IOV PF device removes all the associated VFs,
* which will update the bus->devices list and confuse the
* iterator. Therefore, iterate in reverse so we remove the VFs
* first, then the PF. We do the same in pci_stop_bus_device().
*/
list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
bus_list) {
pci_dev_get(dev);
pci_stop_and_remove_bus_device(dev);
/*
* Ensure that no new Requests will be generated from
* the device.
*/
if (presence) {
pci_read_config_word(dev, PCI_COMMAND, &command);
command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
command |= PCI_COMMAND_INTX_DISABLE;
pci_write_config_word(dev, PCI_COMMAND, command);
}
pci_dev_put(dev);
}
pci_unlock_rescan_remove();
}