pci_dlpar.c

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/*
 * PCI Dynamic LPAR, PCI Hot Plug and PCI EEH recovery code
 * for RPA-compliant PPC64 platform.
 * Copyright (C) 2003 Linda Xie <[email protected]>
 * Copyright (C) 2005 International Business Machines
 *
 * Updates, 2005, John Rose <[email protected]>
 * Updates, 2005, Linas Vepstas <[email protected]>
 *
 * All rights reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#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 list_head *tmp;
    struct device_node *busdn;

    busdn = pci_bus_to_OF_node(bus);
    if (busdn == dn)
        return bus;

    list_for_each(tmp, &bus->children) {
        child = find_bus_among_children(pci_bus_b(tmp), dn);
        if (child)
            break;
    };
    return child;
}

struct pci_bus *
pcibios_find_pci_bus(struct device_node *dn)
{
    struct pci_dn *pdn = dn->data;

    if (!pdn  || !pdn->phb || !pdn->phb->bus)
        return NULL;

    return find_bus_among_children(pdn->phb->bus, dn);
}
EXPORT_SYMBOL_GPL(pcibios_find_pci_bus);

void __pcibios_remove_pci_devices(struct pci_bus *bus, int purge_pe)
{
    struct pci_dev *dev, *tmp;
    struct pci_bus *child_bus;

    /* First go down child busses */
    list_for_each_entry(child_bus, &bus->children, node)
        __pcibios_remove_pci_devices(child_bus, purge_pe);

    pr_debug("PCI: Removing devices on bus %04x:%02x\n",
        pci_domain_nr(bus),  bus->number);
    list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
        pr_debug("     * Removing %s...\n", pci_name(dev));
        eeh_remove_bus_device(dev, purge_pe);
        pci_stop_and_remove_bus_device(dev);
    }
}

void pcibios_remove_pci_devices(struct pci_bus *bus)
{
    __pcibios_remove_pci_devices(bus, 1);
}
EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices);

void pcibios_add_pci_devices(struct pci_bus * bus)
{
    int slotno, num, mode, pass, max;
    struct pci_dev *dev;
    struct device_node *dn = pci_bus_to_OF_node(bus);

    eeh_add_device_tree_early(dn);

    mode = PCI_PROBE_NORMAL;
    if (ppc_md.pci_probe_mode)
        mode = ppc_md.pci_probe_mode(bus);

    if (mode == PCI_PROBE_DEVTREE) {
        /* use ofdt-based probe */
        of_rescan_bus(dn, bus);
    } else if (mode == PCI_PROBE_NORMAL) {
        /* use legacy probe */
        slotno = PCI_SLOT(PCI_DN(dn->child)->devfn);
        num = pci_scan_slot(bus, PCI_DEVFN(slotno, 0));
        if (!num)
            return;
        pcibios_setup_bus_devices(bus);
        max = bus->busn_res.start;
        for (pass=0; pass < 2; pass++)
            list_for_each_entry(dev, &bus->devices, bus_list) {
            if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
                dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
                max = pci_scan_bridge(bus, dev, max, pass);
        }
    }
    pcibios_finish_adding_to_bus(bus);
}
EXPORT_SYMBOL_GPL(pcibios_add_pci_devices);

struct pci_controller * __devinit init_phb_dynamic(struct device_node *dn)
{
    struct pci_controller *phb;

    pr_debug("PCI: Initializing new hotplug PHB %s\n", dn->full_name);

    phb = pcibios_alloc_controller(dn);
    if (!phb)
        return NULL;
    rtas_setup_phb(phb);
    pci_process_bridge_OF_ranges(phb, dn, 0);

    pci_devs_phb_init_dynamic(phb);

    /* Create EEH devices for the PHB */
    eeh_dev_phb_init_dynamic(phb);

    if (dn->child)
        eeh_add_device_tree_early(dn);

    pcibios_scan_phb(phb);
    pcibios_finish_adding_to_bus(phb->bus);

    return phb;
}
EXPORT_SYMBOL_GPL(init_phb_dynamic);

/* RPA-specific bits for removing PHBs */
int remove_phb_dynamic(struct pci_controller *phb)
{
    struct pci_bus *b = phb->bus;
    struct resource *res;
    int rc, i;

    pr_debug("PCI: Removing PHB %04x:%02x...\n",
         pci_domain_nr(b), b->number);

    /* We cannot to remove a root bus that has children */
    if (!(list_empty(&b->children) && list_empty(&b->devices)))
        return -EBUSY;

    /* We -know- there aren't any child devices anymore at this stage
     * and thus, we can safely unmap the IO space as it's not in use
     */
    res = &phb->io_resource;
    if (res->flags & IORESOURCE_IO) {
        rc = pcibios_unmap_io_space(b);
        if (rc) {
            printk(KERN_ERR "%s: failed to unmap IO on bus %s\n",
                   __func__, b->name);
            return 1;
        }
    }

    /* Unregister the bridge device from sysfs and remove the PCI bus */
    device_unregister(b->bridge);
    phb->bus = NULL;
    pci_remove_bus(b);

    /* Now release the IO resource */
    if (res->flags & IORESOURCE_IO)
        release_resource(res);

    /* Release memory resources */
    for (i = 0; i < 3; ++i) {
        res = &phb->mem_resources[i];
        if (!(res->flags & IORESOURCE_MEM))
            continue;
        release_resource(res);
    }

    /* Free pci_controller data structure */
    pcibios_free_controller(phb);

    return 0;
}
EXPORT_SYMBOL_GPL(remove_phb_dynamic);