x86/amd-iommu: Add per IOMMU reference counting

[linux/fpc-iii.git] / drivers / pci / hotplug / ibmphp_ebda.c

/*
 * IBM Hot Plug Controller Driver
 *
 * Written By: Tong Yu, IBM Corporation
 *
 * Copyright (C) 2001,2003 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2001-2003 IBM Corp.
 *
 * 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.
 *
 * Send feedback to <gregkh@us.ibm.com>
 *
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/list.h>
#include <linux/init.h>
#include "ibmphp.h"

/*
 * POST builds data blocks(in this data block definition, a char-1
 * byte, short(or word)-2 byte, long(dword)-4 byte) in the Extended
 * BIOS Data Area which describe the configuration of the hot-plug
 * controllers and resources used by the PCI Hot-Plug devices.
 *
 * This file walks EBDA, maps data block from physical addr,
 * reconstruct linked lists about all system resource(MEM, PFM, IO)
 * already assigned by POST, as well as linked lists about hot plug
 * controllers (ctlr#, slot#, bus&slot features...)
 */

/* Global lists */
LIST_HEAD (ibmphp_ebda_pci_rsrc_head);
LIST_HEAD (ibmphp_slot_head);

/* Local variables */
static struct ebda_hpc_list *hpc_list_ptr;
static struct ebda_rsrc_list *rsrc_list_ptr;
static struct rio_table_hdr *rio_table_ptr = NULL;
static LIST_HEAD (ebda_hpc_head);
static LIST_HEAD (bus_info_head);
static LIST_HEAD (rio_vg_head);
static LIST_HEAD (rio_lo_head);
static LIST_HEAD (opt_vg_head);
static LIST_HEAD (opt_lo_head);
static void __iomem *io_mem;

/* Local functions */
static int ebda_rsrc_controller (void);
static int ebda_rsrc_rsrc (void);
static int ebda_rio_table (void);

static struct ebda_hpc_list * __init alloc_ebda_hpc_list (void)
{
        return kzalloc(sizeof(struct ebda_hpc_list), GFP_KERNEL);
}

static struct controller *alloc_ebda_hpc (u32 slot_count, u32 bus_count)
{
        struct controller *controller;
        struct ebda_hpc_slot *slots;
        struct ebda_hpc_bus *buses;

        controller = kzalloc(sizeof(struct controller), GFP_KERNEL);
        if (!controller)
                goto error;

        slots = kcalloc(slot_count, sizeof(struct ebda_hpc_slot), GFP_KERNEL);
        if (!slots)
                goto error_contr;
        controller->slots = slots;

        buses = kcalloc(bus_count, sizeof(struct ebda_hpc_bus), GFP_KERNEL);
        if (!buses)
                goto error_slots;
        controller->buses = buses;

        return controller;
error_slots:
        kfree(controller->slots);
error_contr:
        kfree(controller);
error:
        return NULL;
}

static void free_ebda_hpc (struct controller *controller)
{
        kfree (controller->slots);
        kfree (controller->buses);
        kfree (controller);
}

static struct ebda_rsrc_list * __init alloc_ebda_rsrc_list (void)
{
        return kzalloc(sizeof(struct ebda_rsrc_list), GFP_KERNEL);
}

static struct ebda_pci_rsrc *alloc_ebda_pci_rsrc (void)
{
        return kzalloc(sizeof(struct ebda_pci_rsrc), GFP_KERNEL);
}

static void __init print_bus_info (void)
{
        struct bus_info *ptr;
        
        list_for_each_entry(ptr, &bus_info_head, bus_info_list) {
                debug ("%s - slot_min = %x\n", __func__, ptr->slot_min);
                debug ("%s - slot_max = %x\n", __func__, ptr->slot_max);
                debug ("%s - slot_count = %x\n", __func__, ptr->slot_count);
                debug ("%s - bus# = %x\n", __func__, ptr->busno);
                debug ("%s - current_speed = %x\n", __func__, ptr->current_speed);
                debug ("%s - controller_id = %x\n", __func__, ptr->controller_id);
                
                debug ("%s - slots_at_33_conv = %x\n", __func__, ptr->slots_at_33_conv);
                debug ("%s - slots_at_66_conv = %x\n", __func__, ptr->slots_at_66_conv);
                debug ("%s - slots_at_66_pcix = %x\n", __func__, ptr->slots_at_66_pcix);
                debug ("%s - slots_at_100_pcix = %x\n", __func__, ptr->slots_at_100_pcix);
                debug ("%s - slots_at_133_pcix = %x\n", __func__, ptr->slots_at_133_pcix);

        }
}

static void print_lo_info (void)
{
        struct rio_detail *ptr;
        debug ("print_lo_info ----\n"); 
        list_for_each_entry(ptr, &rio_lo_head, rio_detail_list) {
                debug ("%s - rio_node_id = %x\n", __func__, ptr->rio_node_id);
                debug ("%s - rio_type = %x\n", __func__, ptr->rio_type);
                debug ("%s - owner_id = %x\n", __func__, ptr->owner_id);
                debug ("%s - first_slot_num = %x\n", __func__, ptr->first_slot_num);
                debug ("%s - wpindex = %x\n", __func__, ptr->wpindex);
                debug ("%s - chassis_num = %x\n", __func__, ptr->chassis_num);

        }
}

static void print_vg_info (void)
{
        struct rio_detail *ptr;
        debug ("%s ---\n", __func__);
        list_for_each_entry(ptr, &rio_vg_head, rio_detail_list) {
                debug ("%s - rio_node_id = %x\n", __func__, ptr->rio_node_id);
                debug ("%s - rio_type = %x\n", __func__, ptr->rio_type);
                debug ("%s - owner_id = %x\n", __func__, ptr->owner_id);
                debug ("%s - first_slot_num = %x\n", __func__, ptr->first_slot_num);
                debug ("%s - wpindex = %x\n", __func__, ptr->wpindex);
                debug ("%s - chassis_num = %x\n", __func__, ptr->chassis_num);

        }
}

static void __init print_ebda_pci_rsrc (void)
{
        struct ebda_pci_rsrc *ptr;

        list_for_each_entry(ptr, &ibmphp_ebda_pci_rsrc_head, ebda_pci_rsrc_list) {
                debug ("%s - rsrc type: %x bus#: %x dev_func: %x start addr: %x end addr: %x\n", 
                        __func__, ptr->rsrc_type ,ptr->bus_num, ptr->dev_fun,ptr->start_addr, ptr->end_addr);
        }
}

static void __init print_ibm_slot (void)
{
        struct slot *ptr;

        list_for_each_entry(ptr, &ibmphp_slot_head, ibm_slot_list) {
                debug ("%s - slot_number: %x\n", __func__, ptr->number);
        }
}

static void __init print_opt_vg (void)
{
        struct opt_rio *ptr;
        debug ("%s ---\n", __func__);
        list_for_each_entry(ptr, &opt_vg_head, opt_rio_list) {
                debug ("%s - rio_type %x\n", __func__, ptr->rio_type);
                debug ("%s - chassis_num: %x\n", __func__, ptr->chassis_num);
                debug ("%s - first_slot_num: %x\n", __func__, ptr->first_slot_num);
                debug ("%s - middle_num: %x\n", __func__, ptr->middle_num);
        }
}

static void __init print_ebda_hpc (void)
{
        struct controller *hpc_ptr;
        u16 index;

        list_for_each_entry(hpc_ptr, &ebda_hpc_head, ebda_hpc_list) {
                for (index = 0; index < hpc_ptr->slot_count; index++) {
                        debug ("%s - physical slot#: %x\n", __func__, hpc_ptr->slots[index].slot_num);
                        debug ("%s - pci bus# of the slot: %x\n", __func__, hpc_ptr->slots[index].slot_bus_num);
                        debug ("%s - index into ctlr addr: %x\n", __func__, hpc_ptr->slots[index].ctl_index);
                        debug ("%s - cap of the slot: %x\n", __func__, hpc_ptr->slots[index].slot_cap);
                }

                for (index = 0; index < hpc_ptr->bus_count; index++) {
                        debug ("%s - bus# of each bus controlled by this ctlr: %x\n", __func__, hpc_ptr->buses[index].bus_num);
                }

                debug ("%s - type of hpc: %x\n", __func__, hpc_ptr->ctlr_type);
                switch (hpc_ptr->ctlr_type) {
                case 1:
                        debug ("%s - bus: %x\n", __func__, hpc_ptr->u.pci_ctlr.bus);
                        debug ("%s - dev_fun: %x\n", __func__, hpc_ptr->u.pci_ctlr.dev_fun);
                        debug ("%s - irq: %x\n", __func__, hpc_ptr->irq);
                        break;

                case 0:
                        debug ("%s - io_start: %x\n", __func__, hpc_ptr->u.isa_ctlr.io_start);
                        debug ("%s - io_end: %x\n", __func__, hpc_ptr->u.isa_ctlr.io_end);
                        debug ("%s - irq: %x\n", __func__, hpc_ptr->irq);
                        break;

                case 2:
                case 4:
                        debug ("%s - wpegbbar: %lx\n", __func__, hpc_ptr->u.wpeg_ctlr.wpegbbar);
                        debug ("%s - i2c_addr: %x\n", __func__, hpc_ptr->u.wpeg_ctlr.i2c_addr);
                        debug ("%s - irq: %x\n", __func__, hpc_ptr->irq);
                        break;
                }
        }
}

int __init ibmphp_access_ebda (void)
{
        u8 format, num_ctlrs, rio_complete, hs_complete;
        u16 ebda_seg, num_entries, next_offset, offset, blk_id, sub_addr, re, rc_id, re_id, base;
        int rc = 0;


        rio_complete = 0;
        hs_complete = 0;

        io_mem = ioremap ((0x40 << 4) + 0x0e, 2);
        if (!io_mem )
                return -ENOMEM;
        ebda_seg = readw (io_mem);
        iounmap (io_mem);
        debug ("returned ebda segment: %x\n", ebda_seg);
        
        io_mem = ioremap(ebda_seg<<4, 1024);
        if (!io_mem )
                return -ENOMEM;
        next_offset = 0x180;

        for (;;) {
                offset = next_offset;
                next_offset = readw (io_mem + offset);  /* offset of next blk */

                offset += 2;
                if (next_offset == 0)   /* 0 indicate it's last blk */
                        break;
                blk_id = readw (io_mem + offset);       /* this blk id */

                offset += 2;
                /* check if it is hot swap block or rio block */
                if (blk_id != 0x4853 && blk_id != 0x4752)
                        continue;
                /* found hs table */
                if (blk_id == 0x4853) {
                        debug ("now enter hot swap block---\n");
                        debug ("hot blk id: %x\n", blk_id);
                        format = readb (io_mem + offset);

                        offset += 1;
                        if (format != 4)
                                goto error_nodev;
                        debug ("hot blk format: %x\n", format);
                        /* hot swap sub blk */
                        base = offset;

                        sub_addr = base;
                        re = readw (io_mem + sub_addr); /* next sub blk */

                        sub_addr += 2;
                        rc_id = readw (io_mem + sub_addr);      /* sub blk id */

                        sub_addr += 2;
                        if (rc_id != 0x5243)
                                goto error_nodev;
                        /* rc sub blk signature  */
                        num_ctlrs = readb (io_mem + sub_addr);

                        sub_addr += 1;
                        hpc_list_ptr = alloc_ebda_hpc_list ();
                        if (!hpc_list_ptr) {
                                rc = -ENOMEM;
                                goto out;
                        }
                        hpc_list_ptr->format = format;
                        hpc_list_ptr->num_ctlrs = num_ctlrs;
                        hpc_list_ptr->phys_addr = sub_addr;     /*  offset of RSRC_CONTROLLER blk */
                        debug ("info about hpc descriptor---\n");
                        debug ("hot blk format: %x\n", format);
                        debug ("num of controller: %x\n", num_ctlrs);
                        debug ("offset of hpc data structure enteries: %x\n ", sub_addr);

                        sub_addr = base + re;   /* re sub blk */
                        /* FIXME: rc is never used/checked */
                        rc = readw (io_mem + sub_addr); /* next sub blk */

                        sub_addr += 2;
                        re_id = readw (io_mem + sub_addr);      /* sub blk id */

                        sub_addr += 2;
                        if (re_id != 0x5245)
                                goto error_nodev;

                        /* signature of re */
                        num_entries = readw (io_mem + sub_addr);

                        sub_addr += 2;  /* offset of RSRC_ENTRIES blk */
                        rsrc_list_ptr = alloc_ebda_rsrc_list ();
                        if (!rsrc_list_ptr ) {
                                rc = -ENOMEM;
                                goto out;
                        }
                        rsrc_list_ptr->format = format;
                        rsrc_list_ptr->num_entries = num_entries;
                        rsrc_list_ptr->phys_addr = sub_addr;

                        debug ("info about rsrc descriptor---\n");
                        debug ("format: %x\n", format);
                        debug ("num of rsrc: %x\n", num_entries);
                        debug ("offset of rsrc data structure enteries: %x\n ", sub_addr);

                        hs_complete = 1;
                } else {
                /* found rio table, blk_id == 0x4752 */
                        debug ("now enter io table ---\n");
                        debug ("rio blk id: %x\n", blk_id);

                        rio_table_ptr = kzalloc(sizeof(struct rio_table_hdr), GFP_KERNEL);
                        if (!rio_table_ptr)
                                return -ENOMEM; 
                        rio_table_ptr->ver_num = readb (io_mem + offset);
                        rio_table_ptr->scal_count = readb (io_mem + offset + 1);
                        rio_table_ptr->riodev_count = readb (io_mem + offset + 2);
                        rio_table_ptr->offset = offset +3 ;
                        
                        debug("info about rio table hdr ---\n");
                        debug("ver_num: %x\nscal_count: %x\nriodev_count: %x\noffset of rio table: %x\n ",
                                rio_table_ptr->ver_num, rio_table_ptr->scal_count,
                                rio_table_ptr->riodev_count, rio_table_ptr->offset);

                        rio_complete = 1;
                }
        }

        if (!hs_complete && !rio_complete)
                goto error_nodev;

        if (rio_table_ptr) {
                if (rio_complete && rio_table_ptr->ver_num == 3) {
                        rc = ebda_rio_table ();
                        if (rc)
                                goto out;
                }
        }
        rc = ebda_rsrc_controller ();
        if (rc)
                goto out;

        rc = ebda_rsrc_rsrc ();
        goto out;
error_nodev:
        rc = -ENODEV;
out:
        iounmap (io_mem);
        return rc;
}

/*
 * map info of scalability details and rio details from physical address
 */
static int __init ebda_rio_table (void)
{
        u16 offset;
        u8 i;
        struct rio_detail *rio_detail_ptr;

        offset = rio_table_ptr->offset;
        offset += 12 * rio_table_ptr->scal_count;

        // we do concern about rio details
        for (i = 0; i < rio_table_ptr->riodev_count; i++) {
                rio_detail_ptr = kzalloc(sizeof(struct rio_detail), GFP_KERNEL);
                if (!rio_detail_ptr)
                        return -ENOMEM;
                rio_detail_ptr->rio_node_id = readb (io_mem + offset);
                rio_detail_ptr->bbar = readl (io_mem + offset + 1);
                rio_detail_ptr->rio_type = readb (io_mem + offset + 5);
                rio_detail_ptr->owner_id = readb (io_mem + offset + 6);
                rio_detail_ptr->port0_node_connect = readb (io_mem + offset + 7);
                rio_detail_ptr->port0_port_connect = readb (io_mem + offset + 8);
                rio_detail_ptr->port1_node_connect = readb (io_mem + offset + 9);
                rio_detail_ptr->port1_port_connect = readb (io_mem + offset + 10);
                rio_detail_ptr->first_slot_num = readb (io_mem + offset + 11);
                rio_detail_ptr->status = readb (io_mem + offset + 12);
                rio_detail_ptr->wpindex = readb (io_mem + offset + 13);
                rio_detail_ptr->chassis_num = readb (io_mem + offset + 14);
//              debug ("rio_node_id: %x\nbbar: %x\nrio_type: %x\nowner_id: %x\nport0_node: %x\nport0_port: %x\nport1_node: %x\nport1_port: %x\nfirst_slot_num: %x\nstatus: %x\n", rio_detail_ptr->rio_node_id, rio_detail_ptr->bbar, rio_detail_ptr->rio_type, rio_detail_ptr->owner_id, rio_detail_ptr->port0_node_connect, rio_detail_ptr->port0_port_connect, rio_detail_ptr->port1_node_connect, rio_detail_ptr->port1_port_connect, rio_detail_ptr->first_slot_num, rio_detail_ptr->status);
                //create linked list of chassis
                if (rio_detail_ptr->rio_type == 4 || rio_detail_ptr->rio_type == 5) 
                        list_add (&rio_detail_ptr->rio_detail_list, &rio_vg_head);
                //create linked list of expansion box                           
                else if (rio_detail_ptr->rio_type == 6 || rio_detail_ptr->rio_type == 7) 
                        list_add (&rio_detail_ptr->rio_detail_list, &rio_lo_head);
                else 
                        // not in my concern
                        kfree (rio_detail_ptr);
                offset += 15;
        }
        print_lo_info ();
        print_vg_info ();
        return 0;
}

/*
 * reorganizing linked list of chassis   
 */
static struct opt_rio *search_opt_vg (u8 chassis_num)
{
        struct opt_rio *ptr;
        list_for_each_entry(ptr, &opt_vg_head, opt_rio_list) {
                if (ptr->chassis_num == chassis_num)
                        return ptr;
        }               
        return NULL;
}

static int __init combine_wpg_for_chassis (void)
{
        struct opt_rio *opt_rio_ptr = NULL;
        struct rio_detail *rio_detail_ptr = NULL;
        
        list_for_each_entry(rio_detail_ptr, &rio_vg_head, rio_detail_list) {
                opt_rio_ptr = search_opt_vg (rio_detail_ptr->chassis_num);
                if (!opt_rio_ptr) {
                        opt_rio_ptr = kzalloc(sizeof(struct opt_rio), GFP_KERNEL);
                        if (!opt_rio_ptr)
                                return -ENOMEM;
                        opt_rio_ptr->rio_type = rio_detail_ptr->rio_type;
                        opt_rio_ptr->chassis_num = rio_detail_ptr->chassis_num;
                        opt_rio_ptr->first_slot_num = rio_detail_ptr->first_slot_num;
                        opt_rio_ptr->middle_num = rio_detail_ptr->first_slot_num;
                        list_add (&opt_rio_ptr->opt_rio_list, &opt_vg_head);
                } else {        
                        opt_rio_ptr->first_slot_num = min (opt_rio_ptr->first_slot_num, rio_detail_ptr->first_slot_num);
                        opt_rio_ptr->middle_num = max (opt_rio_ptr->middle_num, rio_detail_ptr->first_slot_num);
                }       
        }
        print_opt_vg ();
        return 0;       
}       

/*
 * reorganizing linked list of expansion box
 */
static struct opt_rio_lo *search_opt_lo (u8 chassis_num)
{
        struct opt_rio_lo *ptr;
        list_for_each_entry(ptr, &opt_lo_head, opt_rio_lo_list) {
                if (ptr->chassis_num == chassis_num)
                        return ptr;
        }               
        return NULL;
}

static int combine_wpg_for_expansion (void)
{
        struct opt_rio_lo *opt_rio_lo_ptr = NULL;
        struct rio_detail *rio_detail_ptr = NULL;
        
        list_for_each_entry(rio_detail_ptr, &rio_lo_head, rio_detail_list) {
                opt_rio_lo_ptr = search_opt_lo (rio_detail_ptr->chassis_num);
                if (!opt_rio_lo_ptr) {
                        opt_rio_lo_ptr = kzalloc(sizeof(struct opt_rio_lo), GFP_KERNEL);
                        if (!opt_rio_lo_ptr)
                                return -ENOMEM;
                        opt_rio_lo_ptr->rio_type = rio_detail_ptr->rio_type;
                        opt_rio_lo_ptr->chassis_num = rio_detail_ptr->chassis_num;
                        opt_rio_lo_ptr->first_slot_num = rio_detail_ptr->first_slot_num;
                        opt_rio_lo_ptr->middle_num = rio_detail_ptr->first_slot_num;
                        opt_rio_lo_ptr->pack_count = 1;
                        
                        list_add (&opt_rio_lo_ptr->opt_rio_lo_list, &opt_lo_head);
                } else {        
                        opt_rio_lo_ptr->first_slot_num = min (opt_rio_lo_ptr->first_slot_num, rio_detail_ptr->first_slot_num);
                        opt_rio_lo_ptr->middle_num = max (opt_rio_lo_ptr->middle_num, rio_detail_ptr->first_slot_num);
                        opt_rio_lo_ptr->pack_count = 2;
                }       
        }
        return 0;       
}
        

/* Since we don't know the max slot number per each chassis, hence go
 * through the list of all chassis to find out the range
 * Arguments: slot_num, 1st slot number of the chassis we think we are on, 
 * var (0 = chassis, 1 = expansion box) 
 */
static int first_slot_num (u8 slot_num, u8 first_slot, u8 var)
{
        struct opt_rio *opt_vg_ptr = NULL;
        struct opt_rio_lo *opt_lo_ptr = NULL;
        int rc = 0;

        if (!var) {
                list_for_each_entry(opt_vg_ptr, &opt_vg_head, opt_rio_list) {
                        if ((first_slot < opt_vg_ptr->first_slot_num) && (slot_num >= opt_vg_ptr->first_slot_num)) { 
                                rc = -ENODEV;
                                break;
                        }
                }
        } else {
                list_for_each_entry(opt_lo_ptr, &opt_lo_head, opt_rio_lo_list) {
                        if ((first_slot < opt_lo_ptr->first_slot_num) && (slot_num >= opt_lo_ptr->first_slot_num)) {
                                rc = -ENODEV;
                                break;
                        }
                }
        }
        return rc;
}

static struct opt_rio_lo * find_rxe_num (u8 slot_num)
{
        struct opt_rio_lo *opt_lo_ptr;

        list_for_each_entry(opt_lo_ptr, &opt_lo_head, opt_rio_lo_list) {
                //check to see if this slot_num belongs to expansion box
                if ((slot_num >= opt_lo_ptr->first_slot_num) && (!first_slot_num (slot_num, opt_lo_ptr->first_slot_num, 1))) 
                        return opt_lo_ptr;
        }
        return NULL;
}

static struct opt_rio * find_chassis_num (u8 slot_num)
{
        struct opt_rio *opt_vg_ptr;

        list_for_each_entry(opt_vg_ptr, &opt_vg_head, opt_rio_list) {
                //check to see if this slot_num belongs to chassis 
                if ((slot_num >= opt_vg_ptr->first_slot_num) && (!first_slot_num (slot_num, opt_vg_ptr->first_slot_num, 0))) 
                        return opt_vg_ptr;
        }
        return NULL;
}

/* This routine will find out how many slots are in the chassis, so that
 * the slot numbers for rxe100 would start from 1, and not from 7, or 6 etc
 */
static u8 calculate_first_slot (u8 slot_num)
{
        u8 first_slot = 1;
        struct slot * slot_cur;
        
        list_for_each_entry(slot_cur, &ibmphp_slot_head, ibm_slot_list) {
                if (slot_cur->ctrl) {
                        if ((slot_cur->ctrl->ctlr_type != 4) && (slot_cur->ctrl->ending_slot_num > first_slot) && (slot_num > slot_cur->ctrl->ending_slot_num)) 
                                first_slot = slot_cur->ctrl->ending_slot_num;
                }
        }                       
        return first_slot + 1;

}

#define SLOT_NAME_SIZE 30

static char *create_file_name (struct slot * slot_cur)
{
        struct opt_rio *opt_vg_ptr = NULL;
        struct opt_rio_lo *opt_lo_ptr = NULL;
        static char str[SLOT_NAME_SIZE];
        int which = 0; /* rxe = 1, chassis = 0 */
        u8 number = 1; /* either chassis or rxe # */
        u8 first_slot = 1;
        u8 slot_num;
        u8 flag = 0;

        if (!slot_cur) {
                err ("Structure passed is empty\n");
                return NULL;
        }
        
        slot_num = slot_cur->number;

        memset (str, 0, sizeof(str));
        
        if (rio_table_ptr) {
                if (rio_table_ptr->ver_num == 3) {
                        opt_vg_ptr = find_chassis_num (slot_num);
                        opt_lo_ptr = find_rxe_num (slot_num);
                }
        }
        if (opt_vg_ptr) {
                if (opt_lo_ptr) {
                        if ((slot_num - opt_vg_ptr->first_slot_num) > (slot_num - opt_lo_ptr->first_slot_num)) {
                                number = opt_lo_ptr->chassis_num;
                                first_slot = opt_lo_ptr->first_slot_num;
                                which = 1; /* it is RXE */
                        } else {
                                first_slot = opt_vg_ptr->first_slot_num;
                                number = opt_vg_ptr->chassis_num;
                                which = 0;
                        }
                } else {
                        first_slot = opt_vg_ptr->first_slot_num;
                        number = opt_vg_ptr->chassis_num;
                        which = 0;
                }
                ++flag;
        } else if (opt_lo_ptr) {
                number = opt_lo_ptr->chassis_num;
                first_slot = opt_lo_ptr->first_slot_num;
                which = 1;
                ++flag;
        } else if (rio_table_ptr) {
                if (rio_table_ptr->ver_num == 3) {
                        /* if both NULL and we DO have correct RIO table in BIOS */
                        return NULL;
                }
        } 
        if (!flag) {
                if (slot_cur->ctrl->ctlr_type == 4) {
                        first_slot = calculate_first_slot (slot_num);
                        which = 1;
                } else {
                        which = 0;
                }
        }

        sprintf(str, "%s%dslot%d",
                which == 0 ? "chassis" : "rxe",
                number, slot_num - first_slot + 1);
        return str;
}

static int fillslotinfo(struct hotplug_slot *hotplug_slot)
{
        struct slot *slot;
        int rc = 0;

        if (!hotplug_slot || !hotplug_slot->private)
                return -EINVAL;

        slot = hotplug_slot->private;
        rc = ibmphp_hpc_readslot(slot, READ_ALLSTAT, NULL);
        if (rc)
                return rc;

        // power - enabled:1  not:0
        hotplug_slot->info->power_status = SLOT_POWER(slot->status);

        // attention - off:0, on:1, blinking:2
        hotplug_slot->info->attention_status = SLOT_ATTN(slot->status, slot->ext_status);

        // latch - open:1 closed:0
        hotplug_slot->info->latch_status = SLOT_LATCH(slot->status);

        // pci board - present:1 not:0
        if (SLOT_PRESENT (slot->status))
                hotplug_slot->info->adapter_status = 1;
        else
                hotplug_slot->info->adapter_status = 0;
/*
        if (slot->bus_on->supported_bus_mode
                && (slot->bus_on->supported_speed == BUS_SPEED_66))
                hotplug_slot->info->max_bus_speed_status = BUS_SPEED_66PCIX;
        else
                hotplug_slot->info->max_bus_speed_status = slot->bus_on->supported_speed;
*/

        return rc;
}

static void release_slot(struct hotplug_slot *hotplug_slot)
{
        struct slot *slot;

        if (!hotplug_slot || !hotplug_slot->private)
                return;

        slot = hotplug_slot->private;
        kfree(slot->hotplug_slot->info);
        kfree(slot->hotplug_slot);
        slot->ctrl = NULL;
        slot->bus_on = NULL;

        /* we don't want to actually remove the resources, since free_resources will do just that */
        ibmphp_unconfigure_card(&slot, -1);

        kfree (slot);
}

static struct pci_driver ibmphp_driver;

/*
 * map info (ctlr-id, slot count, slot#.. bus count, bus#, ctlr type...) of
 * each hpc from physical address to a list of hot plug controllers based on
 * hpc descriptors.
 */
static int __init ebda_rsrc_controller (void)
{
        u16 addr, addr_slot, addr_bus;
        u8 ctlr_id, temp, bus_index;
        u16 ctlr, slot, bus;
        u16 slot_num, bus_num, index;
        struct hotplug_slot *hp_slot_ptr;
        struct controller *hpc_ptr;
        struct ebda_hpc_bus *bus_ptr;
        struct ebda_hpc_slot *slot_ptr;
        struct bus_info *bus_info_ptr1, *bus_info_ptr2;
        int rc;
        struct slot *tmp_slot;
        char name[SLOT_NAME_SIZE];

        addr = hpc_list_ptr->phys_addr;
        for (ctlr = 0; ctlr < hpc_list_ptr->num_ctlrs; ctlr++) {
                bus_index = 1;
                ctlr_id = readb (io_mem + addr);
                addr += 1;
                slot_num = readb (io_mem + addr);

                addr += 1;
                addr_slot = addr;       /* offset of slot structure */
                addr += (slot_num * 4);

                bus_num = readb (io_mem + addr);

                addr += 1;
                addr_bus = addr;        /* offset of bus */
                addr += (bus_num * 9);  /* offset of ctlr_type */
                temp = readb (io_mem + addr);

                addr += 1;
                /* init hpc structure */
                hpc_ptr = alloc_ebda_hpc (slot_num, bus_num);
                if (!hpc_ptr ) {
                        rc = -ENOMEM;
                        goto error_no_hpc;
                }
                hpc_ptr->ctlr_id = ctlr_id;
                hpc_ptr->ctlr_relative_id = ctlr;
                hpc_ptr->slot_count = slot_num;
                hpc_ptr->bus_count = bus_num;
                debug ("now enter ctlr data struture ---\n");
                debug ("ctlr id: %x\n", ctlr_id);
                debug ("ctlr_relative_id: %x\n", hpc_ptr->ctlr_relative_id);
                debug ("count of slots controlled by this ctlr: %x\n", slot_num);
                debug ("count of buses controlled by this ctlr: %x\n", bus_num);

                /* init slot structure, fetch slot, bus, cap... */
                slot_ptr = hpc_ptr->slots;
                for (slot = 0; slot < slot_num; slot++) {
                        slot_ptr->slot_num = readb (io_mem + addr_slot);
                        slot_ptr->slot_bus_num = readb (io_mem + addr_slot + slot_num);
                        slot_ptr->ctl_index = readb (io_mem + addr_slot + 2*slot_num);
                        slot_ptr->slot_cap = readb (io_mem + addr_slot + 3*slot_num);

                        // create bus_info lined list --- if only one slot per bus: slot_min = slot_max 

                        bus_info_ptr2 = ibmphp_find_same_bus_num (slot_ptr->slot_bus_num);
                        if (!bus_info_ptr2) {
                                bus_info_ptr1 = kzalloc(sizeof(struct bus_info), GFP_KERNEL);
                                if (!bus_info_ptr1) {
                                        rc = -ENOMEM;
                                        goto error_no_hp_slot;
                                }
                                bus_info_ptr1->slot_min = slot_ptr->slot_num;
                                bus_info_ptr1->slot_max = slot_ptr->slot_num;
                                bus_info_ptr1->slot_count += 1;
                                bus_info_ptr1->busno = slot_ptr->slot_bus_num;
                                bus_info_ptr1->index = bus_index++;
                                bus_info_ptr1->current_speed = 0xff;
                                bus_info_ptr1->current_bus_mode = 0xff;
                                
                                bus_info_ptr1->controller_id = hpc_ptr->ctlr_id;
                                
                                list_add_tail (&bus_info_ptr1->bus_info_list, &bus_info_head);

                        } else {
                                bus_info_ptr2->slot_min = min (bus_info_ptr2->slot_min, slot_ptr->slot_num);
                                bus_info_ptr2->slot_max = max (bus_info_ptr2->slot_max, slot_ptr->slot_num);
                                bus_info_ptr2->slot_count += 1;

                        }

                        // end of creating the bus_info linked list

                        slot_ptr++;
                        addr_slot += 1;
                }

                /* init bus structure */
                bus_ptr = hpc_ptr->buses;
                for (bus = 0; bus < bus_num; bus++) {
                        bus_ptr->bus_num = readb (io_mem + addr_bus + bus);
                        bus_ptr->slots_at_33_conv = readb (io_mem + addr_bus + bus_num + 8 * bus);
                        bus_ptr->slots_at_66_conv = readb (io_mem + addr_bus + bus_num + 8 * bus + 1);

                        bus_ptr->slots_at_66_pcix = readb (io_mem + addr_bus + bus_num + 8 * bus + 2);

                        bus_ptr->slots_at_100_pcix = readb (io_mem + addr_bus + bus_num + 8 * bus + 3);

                        bus_ptr->slots_at_133_pcix = readb (io_mem + addr_bus + bus_num + 8 * bus + 4);

                        bus_info_ptr2 = ibmphp_find_same_bus_num (bus_ptr->bus_num);
                        if (bus_info_ptr2) {
                                bus_info_ptr2->slots_at_33_conv = bus_ptr->slots_at_33_conv;
                                bus_info_ptr2->slots_at_66_conv = bus_ptr->slots_at_66_conv;
                                bus_info_ptr2->slots_at_66_pcix = bus_ptr->slots_at_66_pcix;
                                bus_info_ptr2->slots_at_100_pcix = bus_ptr->slots_at_100_pcix;
                                bus_info_ptr2->slots_at_133_pcix = bus_ptr->slots_at_133_pcix; 
                        }
                        bus_ptr++;
                }

                hpc_ptr->ctlr_type = temp;

                switch (hpc_ptr->ctlr_type) {
                        case 1:
                                hpc_ptr->u.pci_ctlr.bus = readb (io_mem + addr);
                                hpc_ptr->u.pci_ctlr.dev_fun = readb (io_mem + addr + 1);
                                hpc_ptr->irq = readb (io_mem + addr + 2);
                                addr += 3;
                                debug ("ctrl bus = %x, ctlr devfun = %x, irq = %x\n", 
                                        hpc_ptr->u.pci_ctlr.bus,
                                        hpc_ptr->u.pci_ctlr.dev_fun, hpc_ptr->irq);
                                break;

                        case 0:
                                hpc_ptr->u.isa_ctlr.io_start = readw (io_mem + addr);
                                hpc_ptr->u.isa_ctlr.io_end = readw (io_mem + addr + 2);
                                if (!request_region (hpc_ptr->u.isa_ctlr.io_start,
                                                     (hpc_ptr->u.isa_ctlr.io_end - hpc_ptr->u.isa_ctlr.io_start + 1),
                                                     "ibmphp")) {
                                        rc = -ENODEV;
                                        goto error_no_hp_slot;
                                }
                                hpc_ptr->irq = readb (io_mem + addr + 4);
                                addr += 5;
                                break;

                        case 2:
                        case 4:
                                hpc_ptr->u.wpeg_ctlr.wpegbbar = readl (io_mem + addr);
                                hpc_ptr->u.wpeg_ctlr.i2c_addr = readb (io_mem + addr + 4);
                                hpc_ptr->irq = readb (io_mem + addr + 5);
                                addr += 6;
                                break;
                        default:
                                rc = -ENODEV;
                                goto error_no_hp_slot;
                }

                //reorganize chassis' linked list
                combine_wpg_for_chassis ();
                combine_wpg_for_expansion ();
                hpc_ptr->revision = 0xff;
                hpc_ptr->options = 0xff;
                hpc_ptr->starting_slot_num = hpc_ptr->slots[0].slot_num;
                hpc_ptr->ending_slot_num = hpc_ptr->slots[slot_num-1].slot_num;

                // register slots with hpc core as well as create linked list of ibm slot
                for (index = 0; index < hpc_ptr->slot_count; index++) {

                        hp_slot_ptr = kzalloc(sizeof(*hp_slot_ptr), GFP_KERNEL);
                        if (!hp_slot_ptr) {
                                rc = -ENOMEM;
                                goto error_no_hp_slot;
                        }

                        hp_slot_ptr->info = kzalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL);
                        if (!hp_slot_ptr->info) {
                                rc = -ENOMEM;
                                goto error_no_hp_info;
                        }

                        tmp_slot = kzalloc(sizeof(*tmp_slot), GFP_KERNEL);
                        if (!tmp_slot) {
                                rc = -ENOMEM;
                                goto error_no_slot;
                        }

                        tmp_slot->flag = 1;

                        tmp_slot->capabilities = hpc_ptr->slots[index].slot_cap;
                        if ((hpc_ptr->slots[index].slot_cap & EBDA_SLOT_133_MAX) == EBDA_SLOT_133_MAX)
                                tmp_slot->supported_speed =  3;
                        else if ((hpc_ptr->slots[index].slot_cap & EBDA_SLOT_100_MAX) == EBDA_SLOT_100_MAX)
                                tmp_slot->supported_speed =  2;
                        else if ((hpc_ptr->slots[index].slot_cap & EBDA_SLOT_66_MAX) == EBDA_SLOT_66_MAX)
                                tmp_slot->supported_speed =  1;
                                
                        if ((hpc_ptr->slots[index].slot_cap & EBDA_SLOT_PCIX_CAP) == EBDA_SLOT_PCIX_CAP)
                                tmp_slot->supported_bus_mode = 1;
                        else
                                tmp_slot->supported_bus_mode = 0;


                        tmp_slot->bus = hpc_ptr->slots[index].slot_bus_num;

                        bus_info_ptr1 = ibmphp_find_same_bus_num (hpc_ptr->slots[index].slot_bus_num);
                        if (!bus_info_ptr1) {
                                kfree(tmp_slot);
                                rc = -ENODEV;
                                goto error;
                        }
                        tmp_slot->bus_on = bus_info_ptr1;
                        bus_info_ptr1 = NULL;
                        tmp_slot->ctrl = hpc_ptr;

                        tmp_slot->ctlr_index = hpc_ptr->slots[index].ctl_index;
                        tmp_slot->number = hpc_ptr->slots[index].slot_num;
                        tmp_slot->hotplug_slot = hp_slot_ptr;

                        hp_slot_ptr->private = tmp_slot;
                        hp_slot_ptr->release = release_slot;

                        rc = fillslotinfo(hp_slot_ptr);
                        if (rc)
                                goto error;

                        rc = ibmphp_init_devno ((struct slot **) &hp_slot_ptr->private);
                        if (rc)
                                goto error;
                        hp_slot_ptr->ops = &ibmphp_hotplug_slot_ops;

                        // end of registering ibm slot with hotplug core

                        list_add (& ((struct slot *)(hp_slot_ptr->private))->ibm_slot_list, &ibmphp_slot_head);
                }

                print_bus_info ();
                list_add (&hpc_ptr->ebda_hpc_list, &ebda_hpc_head );

        }                       /* each hpc  */

        list_for_each_entry(tmp_slot, &ibmphp_slot_head, ibm_slot_list) {
                snprintf(name, SLOT_NAME_SIZE, "%s", create_file_name(tmp_slot));
                pci_hp_register(tmp_slot->hotplug_slot,
                        pci_find_bus(0, tmp_slot->bus), tmp_slot->device, name);
        }

        print_ebda_hpc ();
        print_ibm_slot ();
        return 0;

error:
        kfree (hp_slot_ptr->private);
error_no_slot:
        kfree (hp_slot_ptr->info);
error_no_hp_info:
        kfree (hp_slot_ptr);
error_no_hp_slot:
        free_ebda_hpc (hpc_ptr);
error_no_hpc:
        iounmap (io_mem);
        return rc;
}

/* 
 * map info (bus, devfun, start addr, end addr..) of i/o, memory,
 * pfm from the physical addr to a list of resource.
 */
static int __init ebda_rsrc_rsrc (void)
{
        u16 addr;
        short rsrc;
        u8 type, rsrc_type;
        struct ebda_pci_rsrc *rsrc_ptr;

        addr = rsrc_list_ptr->phys_addr;
        debug ("now entering rsrc land\n");
        debug ("offset of rsrc: %x\n", rsrc_list_ptr->phys_addr);

        for (rsrc = 0; rsrc < rsrc_list_ptr->num_entries; rsrc++) {
                type = readb (io_mem + addr);

                addr += 1;
                rsrc_type = type & EBDA_RSRC_TYPE_MASK;

                if (rsrc_type == EBDA_IO_RSRC_TYPE) {
                        rsrc_ptr = alloc_ebda_pci_rsrc ();
                        if (!rsrc_ptr) {
                                iounmap (io_mem);
                                return -ENOMEM;
                        }
                        rsrc_ptr->rsrc_type = type;

                        rsrc_ptr->bus_num = readb (io_mem + addr);
                        rsrc_ptr->dev_fun = readb (io_mem + addr + 1);
                        rsrc_ptr->start_addr = readw (io_mem + addr + 2);
                        rsrc_ptr->end_addr = readw (io_mem + addr + 4);
                        addr += 6;

                        debug ("rsrc from io type ----\n");
                        debug ("rsrc type: %x bus#: %x dev_func: %x start addr: %x end addr: %x\n",
                                rsrc_ptr->rsrc_type, rsrc_ptr->bus_num, rsrc_ptr->dev_fun, rsrc_ptr->start_addr, rsrc_ptr->end_addr);

                        list_add (&rsrc_ptr->ebda_pci_rsrc_list, &ibmphp_ebda_pci_rsrc_head);
                }

                if (rsrc_type == EBDA_MEM_RSRC_TYPE || rsrc_type == EBDA_PFM_RSRC_TYPE) {
                        rsrc_ptr = alloc_ebda_pci_rsrc ();
                        if (!rsrc_ptr ) {
                                iounmap (io_mem);
                                return -ENOMEM;
                        }
                        rsrc_ptr->rsrc_type = type;

                        rsrc_ptr->bus_num = readb (io_mem + addr);
                        rsrc_ptr->dev_fun = readb (io_mem + addr + 1);
                        rsrc_ptr->start_addr = readl (io_mem + addr + 2);
                        rsrc_ptr->end_addr = readl (io_mem + addr + 6);
                        addr += 10;

                        debug ("rsrc from mem or pfm ---\n");
                        debug ("rsrc type: %x bus#: %x dev_func: %x start addr: %x end addr: %x\n", 
                                rsrc_ptr->rsrc_type, rsrc_ptr->bus_num, rsrc_ptr->dev_fun, rsrc_ptr->start_addr, rsrc_ptr->end_addr);

                        list_add (&rsrc_ptr->ebda_pci_rsrc_list, &ibmphp_ebda_pci_rsrc_head);
                }
        }
        kfree (rsrc_list_ptr);
        rsrc_list_ptr = NULL;
        print_ebda_pci_rsrc ();
        return 0;
}

u16 ibmphp_get_total_controllers (void)
{
        return hpc_list_ptr->num_ctlrs;
}

struct slot *ibmphp_get_slot_from_physical_num (u8 physical_num)
{
        struct slot *slot;

        list_for_each_entry(slot, &ibmphp_slot_head, ibm_slot_list) {
                if (slot->number == physical_num)
                        return slot;
        }
        return NULL;
}

/* To find:
 *      - the smallest slot number
 *      - the largest slot number
 *      - the total number of the slots based on each bus
 *        (if only one slot per bus slot_min = slot_max )
 */
struct bus_info *ibmphp_find_same_bus_num (u32 num)
{
        struct bus_info *ptr;

        list_for_each_entry(ptr, &bus_info_head, bus_info_list) {
                if (ptr->busno == num) 
                         return ptr;
        }
        return NULL;
}

/*  Finding relative bus number, in order to map corresponding
 *  bus register
 */
int ibmphp_get_bus_index (u8 num)
{
        struct bus_info *ptr;

        list_for_each_entry(ptr, &bus_info_head, bus_info_list) {
                if (ptr->busno == num)  
                        return ptr->index;
        }
        return -ENODEV;
}

void ibmphp_free_bus_info_queue (void)
{
        struct bus_info *bus_info;
        struct list_head *list;
        struct list_head *next;

        list_for_each_safe (list, next, &bus_info_head ) {
                bus_info = list_entry (list, struct bus_info, bus_info_list);
                kfree (bus_info);
        }
}

void ibmphp_free_ebda_hpc_queue (void)
{
        struct controller *controller = NULL;
        struct list_head *list;
        struct list_head *next;
        int pci_flag = 0;

        list_for_each_safe (list, next, &ebda_hpc_head) {
                controller = list_entry (list, struct controller, ebda_hpc_list);
                if (controller->ctlr_type == 0)
                        release_region (controller->u.isa_ctlr.io_start, (controller->u.isa_ctlr.io_end - controller->u.isa_ctlr.io_start + 1));
                else if ((controller->ctlr_type == 1) && (!pci_flag)) {
                        ++pci_flag;
                        pci_unregister_driver (&ibmphp_driver);
                }
                free_ebda_hpc (controller);
        }
}

void ibmphp_free_ebda_pci_rsrc_queue (void)
{
        struct ebda_pci_rsrc *resource;
        struct list_head *list;
        struct list_head *next;

        list_for_each_safe (list, next, &ibmphp_ebda_pci_rsrc_head) {
                resource = list_entry (list, struct ebda_pci_rsrc, ebda_pci_rsrc_list);
                kfree (resource);
                resource = NULL;
        }
}

static struct pci_device_id id_table[] = {
        {
                .vendor         = PCI_VENDOR_ID_IBM,
                .device         = HPC_DEVICE_ID,
                .subvendor      = PCI_VENDOR_ID_IBM,
                .subdevice      = HPC_SUBSYSTEM_ID,
                .class          = ((PCI_CLASS_SYSTEM_PCI_HOTPLUG << 8) | 0x00),
        }, {}
};              

MODULE_DEVICE_TABLE(pci, id_table);

static int ibmphp_probe (struct pci_dev *, const struct pci_device_id *);
static struct pci_driver ibmphp_driver = {
        .name           = "ibmphp",
        .id_table       = id_table,
        .probe          = ibmphp_probe,
};

int ibmphp_register_pci (void)
{
        struct controller *ctrl;
        int rc = 0;

        list_for_each_entry(ctrl, &ebda_hpc_head, ebda_hpc_list) {
                if (ctrl->ctlr_type == 1) {
                        rc = pci_register_driver(&ibmphp_driver);
                        break;
                }
        }
        return rc;
}
static int ibmphp_probe (struct pci_dev * dev, const struct pci_device_id *ids)
{
        struct controller *ctrl;

        debug ("inside ibmphp_probe\n");
        
        list_for_each_entry(ctrl, &ebda_hpc_head, ebda_hpc_list) {
                if (ctrl->ctlr_type == 1) {
                        if ((dev->devfn == ctrl->u.pci_ctlr.dev_fun) && (dev->bus->number == ctrl->u.pci_ctlr.bus)) {
                                ctrl->ctrl_dev = dev;
                                debug ("found device!!!\n");
                                debug ("dev->device = %x, dev->subsystem_device = %x\n", dev->device, dev->subsystem_device);
                                return 0;
                        }
                }
        }
        return -ENODEV;
}