pci_dn.c

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/*
 * pci_dn.c
 *
 * Copyright (C) 2001 Todd Inglett, IBM Corporation
 *
 * PCI manipulation via device_nodes.
 *
 * 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.  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/gfp.h>

#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/firmware.h>

/*
 * Traverse_func that inits the PCI fields of the device node.
 * NOTE: this *must* be done before read/write config to the device.
 */
void * __devinit update_dn_pci_info(struct device_node *dn, void *data)
{
    struct pci_controller *phb = data;
    const int *type =
        of_get_property(dn, "ibm,pci-config-space-type", NULL);
    const u32 *regs;
    struct pci_dn *pdn;

    pdn = zalloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
    if (pdn == NULL)
        return NULL;
    dn->data = pdn;
    pdn->node = dn;
    pdn->phb = phb;
#ifdef CONFIG_PPC_POWERNV
    pdn->pe_number = IODA_INVALID_PE;
#endif
    regs = of_get_property(dn, "reg", NULL);
    if (regs) {
        /* First register entry is addr (00BBSS00)  */
        pdn->busno = (regs[0] >> 16) & 0xff;
        pdn->devfn = (regs[0] >> 8) & 0xff;
    }

    pdn->pci_ext_config_space = (type && *type == 1);
    return NULL;
}

/*
 * Traverse a device tree stopping each PCI device in the tree.
 * This is done depth first.  As each node is processed, a "pre"
 * function is called and the children are processed recursively.
 *
 * The "pre" func returns a value.  If non-zero is returned from
 * the "pre" func, the traversal stops and this value is returned.
 * This return value is useful when using traverse as a method of
 * finding a device.
 *
 * NOTE: we do not run the func for devices that do not appear to
 * be PCI except for the start node which we assume (this is good
 * because the start node is often a phb which may be missing PCI
 * properties).
 * We use the class-code as an indicator. If we run into
 * one of these nodes we also assume its siblings are non-pci for
 * performance.
 */
void *traverse_pci_devices(struct device_node *start, traverse_func pre,
        void *data)
{
    struct device_node *dn, *nextdn;
    void *ret;

    /* We started with a phb, iterate all childs */
    for (dn = start->child; dn; dn = nextdn) {
        const u32 *classp;
        u32 class;

        nextdn = NULL;
        classp = of_get_property(dn, "class-code", NULL);
        class = classp ? *classp : 0;

        if (pre && ((ret = pre(dn, data)) != NULL))
            return ret;

        /* If we are a PCI bridge, go down */
        if (dn->child && ((class >> 8) == PCI_CLASS_BRIDGE_PCI ||
                  (class >> 8) == PCI_CLASS_BRIDGE_CARDBUS))
            /* Depth first...do children */
            nextdn = dn->child;
        else if (dn->sibling)
            /* ok, try next sibling instead. */
            nextdn = dn->sibling;
        if (!nextdn) {
            /* Walk up to next valid sibling. */
            do {
                dn = dn->parent;
                if (dn == start)
                    return NULL;
            } while (dn->sibling == NULL);
            nextdn = dn->sibling;
        }
    }
    return NULL;
}

void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb)
{
    struct device_node *dn = phb->dn;
    struct pci_dn *pdn;

    /* PHB nodes themselves must not match */
    update_dn_pci_info(dn, phb);
    pdn = dn->data;
    if (pdn) {
        pdn->devfn = pdn->busno = -1;
        pdn->phb = phb;
    }

    /* Update dn->phb ptrs for new phb and children devices */
    traverse_pci_devices(dn, update_dn_pci_info, phb);
}

void __init pci_devs_phb_init(void)
{
    struct pci_controller *phb, *tmp;

    /* This must be done first so the device nodes have valid pci info! */
    list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
        pci_devs_phb_init_dynamic(phb);
}