mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-30 06:46:41 +07:00
9d987eba8e
The current scanning code is really hard to understand because it calls the
same function in a loop where pass value is changed without any comments
explaining it:
for (pass = 0; pass < 2; pass++)
for_each_pci_bridge(dev, bus)
max = pci_scan_bridge(bus, dev, max, pass);
Unfamiliar reader cannot tell easily what is the purpose of this loop
without looking at internals of pci_scan_bridge().
In order to make this bit easier to understand, open-code the loop in
pci_scan_child_bus() and pci_hp_add_bridge() with added comments.
No functional changes intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
151 lines
4.2 KiB
C
151 lines
4.2 KiB
C
/*
|
|
* Derived from "arch/powerpc/platforms/pseries/pci_dlpar.c"
|
|
*
|
|
* Copyright (C) 2003 Linda Xie <lxie@us.ibm.com>
|
|
* Copyright (C) 2005 International Business Machines
|
|
*
|
|
* Updates, 2005, John Rose <johnrose@austin.ibm.com>
|
|
* Updates, 2005, Linas Vepstas <linas@austin.ibm.com>
|
|
* Updates, 2013, Gavin Shan <shangw@linux.vnet.ibm.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/pci.h>
|
|
#include <linux/export.h>
|
|
#include <asm/pci-bridge.h>
|
|
#include <asm/ppc-pci.h>
|
|
#include <asm/firmware.h>
|
|
#include <asm/eeh.h>
|
|
|
|
static struct pci_bus *find_bus_among_children(struct pci_bus *bus,
|
|
struct device_node *dn)
|
|
{
|
|
struct pci_bus *child = NULL;
|
|
struct pci_bus *tmp;
|
|
|
|
if (pci_bus_to_OF_node(bus) == dn)
|
|
return bus;
|
|
|
|
list_for_each_entry(tmp, &bus->children, node) {
|
|
child = find_bus_among_children(tmp, dn);
|
|
if (child)
|
|
break;
|
|
}
|
|
|
|
return child;
|
|
}
|
|
|
|
struct pci_bus *pci_find_bus_by_node(struct device_node *dn)
|
|
{
|
|
struct pci_dn *pdn = PCI_DN(dn);
|
|
|
|
if (!pdn || !pdn->phb || !pdn->phb->bus)
|
|
return NULL;
|
|
|
|
return find_bus_among_children(pdn->phb->bus, dn);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pci_find_bus_by_node);
|
|
|
|
/**
|
|
* pcibios_release_device - release PCI device
|
|
* @dev: PCI device
|
|
*
|
|
* The function is called before releasing the indicated PCI device.
|
|
*/
|
|
void pcibios_release_device(struct pci_dev *dev)
|
|
{
|
|
struct pci_controller *phb = pci_bus_to_host(dev->bus);
|
|
|
|
eeh_remove_device(dev);
|
|
|
|
if (phb->controller_ops.release_device)
|
|
phb->controller_ops.release_device(dev);
|
|
}
|
|
|
|
/**
|
|
* pci_hp_remove_devices - remove all devices under this bus
|
|
* @bus: the indicated PCI bus
|
|
*
|
|
* Remove all of the PCI devices under this bus both from the
|
|
* linux pci device tree, and from the powerpc EEH address cache.
|
|
*/
|
|
void pci_hp_remove_devices(struct pci_bus *bus)
|
|
{
|
|
struct pci_dev *dev, *tmp;
|
|
struct pci_bus *child_bus;
|
|
|
|
/* First go down child busses */
|
|
list_for_each_entry(child_bus, &bus->children, node)
|
|
pci_hp_remove_devices(child_bus);
|
|
|
|
pr_debug("PCI: Removing devices on bus %04x:%02x\n",
|
|
pci_domain_nr(bus), bus->number);
|
|
list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
|
|
pr_debug(" Removing %s...\n", pci_name(dev));
|
|
pci_stop_and_remove_bus_device(dev);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(pci_hp_remove_devices);
|
|
|
|
/**
|
|
* pci_hp_add_devices - adds new pci devices to bus
|
|
* @bus: the indicated PCI bus
|
|
*
|
|
* This routine will find and fixup new pci devices under
|
|
* the indicated bus. This routine presumes that there
|
|
* might already be some devices under this bridge, so
|
|
* it carefully tries to add only new devices. (And that
|
|
* is how this routine differs from other, similar pcibios
|
|
* routines.)
|
|
*/
|
|
void pci_hp_add_devices(struct pci_bus *bus)
|
|
{
|
|
int slotno, mode, max;
|
|
struct pci_dev *dev;
|
|
struct pci_controller *phb;
|
|
struct device_node *dn = pci_bus_to_OF_node(bus);
|
|
|
|
eeh_add_device_tree_early(PCI_DN(dn));
|
|
|
|
phb = pci_bus_to_host(bus);
|
|
|
|
mode = PCI_PROBE_NORMAL;
|
|
if (phb->controller_ops.probe_mode)
|
|
mode = phb->controller_ops.probe_mode(bus);
|
|
|
|
if (mode == PCI_PROBE_DEVTREE) {
|
|
/* use ofdt-based probe */
|
|
of_rescan_bus(dn, bus);
|
|
} else if (mode == PCI_PROBE_NORMAL &&
|
|
dn->child && PCI_DN(dn->child)) {
|
|
/*
|
|
* Use legacy probe. In the partial hotplug case, we
|
|
* probably have grandchildren devices unplugged. So
|
|
* we don't check the return value from pci_scan_slot() in
|
|
* order for fully rescan all the way down to pick them up.
|
|
* They can have been removed during partial hotplug.
|
|
*/
|
|
slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
|
|
pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
|
|
pcibios_setup_bus_devices(bus);
|
|
max = bus->busn_res.start;
|
|
/*
|
|
* Scan bridges that are already configured. We don't touch
|
|
* them unless they are misconfigured (which will be done in
|
|
* the second scan below).
|
|
*/
|
|
for_each_pci_bridge(dev, bus)
|
|
max = pci_scan_bridge(bus, dev, max, 0);
|
|
|
|
/* Scan bridges that need to be reconfigured */
|
|
for_each_pci_bridge(dev, bus)
|
|
max = pci_scan_bridge(bus, dev, max, 1);
|
|
}
|
|
pcibios_finish_adding_to_bus(bus);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pci_hp_add_devices);
|