/*
 * 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 *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;
}

/** 
 * pci_devs_phb_init_dynamic - setup pci devices under this PHB
 * phb: pci-to-host bridge (top-level bridge connecting to cpu)
 *
 * This routine is called both during boot, (before the memory
 * subsystem is set up, before kmalloc is valid) and during the 
 * dynamic lpar operation of adding a PHB to a running system.
 */
void 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);
}

/** 
 * pci_devs_phb_init - Initialize phbs and pci devs under them.
 * 
 * This routine walks over all phb's (pci-host bridges) on the
 * system, and sets up assorted pci-related structures 
 * (including pci info in the device node structs) for each
 * pci device found underneath.  This routine runs once,
 * early in the boot sequence.
 */
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);
}