// SPDX-License-Identifier: GPL-2.0+
/*
 * IBM Hot Plug Controller Driver
 *
 * Written By: Irene Zubarev, IBM Corporation
 *
 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2001,2002 IBM Corp.
 *
 * All rights reserved.
 *
 * Send feedback to <gregkh@us.ibm.com>
 *
 */

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


static int configure_device(struct pci_func *);
static int configure_bridge(struct pci_func **, u8);
static struct res_needed *scan_behind_bridge(struct pci_func *, u8);
static int add_new_bus(struct bus_node *, struct resource_node *, struct resource_node *, struct resource_node *, u8);
static u8 find_sec_number(u8 primary_busno, u8 slotno);

/*
 * NOTE..... If BIOS doesn't provide default routing, we assign:
 * 9 for SCSI, 10 for LAN adapters, and 11 for everything else.
 * If adapter is bridged, then we assign 11 to it and devices behind it.
 * We also assign the same irq numbers for multi function devices.
 * These are PIC mode, so shouldn't matter n.e.ways (hopefully)
 */
static void assign_alt_irq(struct pci_func *cur_func, u8 class_code)
{
        int j;
        for (j = 0; j < 4; j++) {
                if (cur_func->irq[j] == 0xff) {
                        switch (class_code) {
                                case PCI_BASE_CLASS_STORAGE:
                                        cur_func->irq[j] = SCSI_IRQ;
                                        break;
                                case PCI_BASE_CLASS_NETWORK:
                                        cur_func->irq[j] = LAN_IRQ;
                                        break;
                                default:
                                        cur_func->irq[j] = OTHER_IRQ;
                                        break;
                        }
                }
        }
}

/*
 * Configures the device to be added (will allocate needed resources if it
 * can), the device can be a bridge or a regular pci device, can also be
 * multi-functional
 *
 * Input: function to be added
 *
 * TO DO:  The error case with Multifunction device or multi function bridge,
 * if there is an error, will need to go through all previous functions and
 * unconfigure....or can add some code into unconfigure_card....
 */
int ibmphp_configure_card(struct pci_func *func, u8 slotno)
{
        u16 vendor_id;
        u32 class;
        u8 class_code;
        u8 hdr_type, device, sec_number;
        u8 function;
        struct pci_func *newfunc;       /* for multi devices */
        struct pci_func *cur_func, *prev_func;
        int rc, i, j;
        int cleanup_count;
        u8 flag;
        u8 valid_device = 0x00; /* to see if we are able to read from card any device info at all */

        debug("inside configure_card, func->busno = %x\n", func->busno);

        device = func->device;
        cur_func = func;

        /* We only get bus and device from IRQ routing table.  So at this point,
         * func->busno is correct, and func->device contains only device (at the 5
         * highest bits)
         */

        /* For every function on the card */
        for (function = 0x00; function < 0x08; function++) {
                unsigned int devfn = PCI_DEVFN(device, function);
                ibmphp_pci_bus->number = cur_func->busno;

                cur_func->function = function;

                debug("inside the loop, cur_func->busno = %x, cur_func->device = %x, cur_func->function = %x\n",
                        cur_func->busno, cur_func->device, cur_func->function);

                pci_bus_read_config_word(ibmphp_pci_bus, devfn, PCI_VENDOR_ID, &vendor_id);

                debug("vendor_id is %x\n", vendor_id);
                if (vendor_id != PCI_VENDOR_ID_NOTVALID) {
                        /* found correct device!!! */
                        debug("found valid device, vendor_id = %x\n", vendor_id);

                        ++valid_device;

                        /* header: x x x x x x x x
                         *         | |___________|=> 1=PPB bridge, 0=normal device, 2=CardBus Bridge
                         *         |_=> 0 = single function device, 1 = multi-function device
                         */

                        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_HEADER_TYPE, &hdr_type);
                        pci_bus_read_config_dword(ibmphp_pci_bus, devfn, PCI_CLASS_REVISION, &class);

                        class_code = class >> 24;
                        debug("hrd_type = %x, class = %x, class_code %x\n", hdr_type, class, class_code);
                        class >>= 8;    /* to take revision out, class = class.subclass.prog i/f */
                        if (class == PCI_CLASS_NOT_DEFINED_VGA) {
                                err("The device %x is VGA compatible and as is not supported for hot plugging. "
                                     "Please choose another device.\n", cur_func->device);
                                return -ENODEV;
                        } else if (class == PCI_CLASS_DISPLAY_VGA) {
                                err("The device %x is not supported for hot plugging. Please choose another device.\n",
                                     cur_func->device);
                                return -ENODEV;
                        }
                        switch (hdr_type) {
                                case PCI_HEADER_TYPE_NORMAL:
                                        debug("single device case.... vendor id = %x, hdr_type = %x, class = %x\n", vendor_id, hdr_type, class);
                                        assign_alt_irq(cur_func, class_code);
                                        rc = configure_device(cur_func);
                                        if (rc < 0) {
                                                /* We need to do this in case some other BARs were properly inserted */
                                                err("was not able to configure devfunc %x on bus %x.\n",
                                                     cur_func->device, cur_func->busno);
                                                cleanup_count = 6;
                                                goto error;
                                        }
                                        cur_func->next = NULL;
                                        function = 0x8;
                                        break;
                                case PCI_HEADER_TYPE_MULTIDEVICE:
                                        assign_alt_irq(cur_func, class_code);
                                        rc = configure_device(cur_func);
                                        if (rc < 0) {
                                                /* We need to do this in case some other BARs were properly inserted */
                                                err("was not able to configure devfunc %x on bus %x...bailing out\n",
                                                     cur_func->device, cur_func->busno);
                                                cleanup_count = 6;
                                                goto error;
                                        }
                                        newfunc = kzalloc(sizeof(*newfunc), GFP_KERNEL);
                                        if (!newfunc)
                                                return -ENOMEM;

                                        newfunc->busno = cur_func->busno;
                                        newfunc->device = device;
                                        cur_func->next = newfunc;
                                        cur_func = newfunc;
                                        for (j = 0; j < 4; j++)
                                                newfunc->irq[j] = cur_func->irq[j];
                                        break;
                                case PCI_HEADER_TYPE_MULTIBRIDGE:
                                        class >>= 8;
                                        if (class != PCI_CLASS_BRIDGE_PCI) {
                                                err("This %x is not PCI-to-PCI bridge, and as is not supported for hot-plugging.  Please insert another card.\n",
                                                     cur_func->device);
                                                return -ENODEV;
                                        }
                                        assign_alt_irq(cur_func, class_code);
                                        rc = configure_bridge(&cur_func, slotno);
                                        if (rc == -ENODEV) {
                                                err("You chose to insert Single Bridge, or nested bridges, this is not supported...\n");
                                                err("Bus %x, devfunc %x\n", cur_func->busno, cur_func->device);
                                                return rc;
                                        }
                                        if (rc) {
                                                /* We need to do this in case some other BARs were properly inserted */
                                                err("was not able to hot-add PPB properly.\n");
                                                func->bus = 1; /* To indicate to the unconfigure function that this is a PPB */
                                                cleanup_count = 2;
                                                goto error;
                                        }

                                        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_SECONDARY_BUS, &sec_number);
                                        flag = 0;
                                        for (i = 0; i < 32; i++) {
                                                if (func->devices[i]) {
                                                        newfunc = kzalloc(sizeof(*newfunc), GFP_KERNEL);
                                                        if (!newfunc)
                                                                return -ENOMEM;

                                                        newfunc->busno = sec_number;
                                                        newfunc->device = (u8) i;
                                                        for (j = 0; j < 4; j++)
                                                                newfunc->irq[j] = cur_func->irq[j];

                                                        if (flag) {
                                                                for (prev_func = cur_func; prev_func->next; prev_func = prev_func->next) ;
                                                                prev_func->next = newfunc;
                                                        } else
                                                                cur_func->next = newfunc;

                                                        rc = ibmphp_configure_card(newfunc, slotno);
                                                        /* This could only happen if kmalloc failed */
                                                        if (rc) {
                                                                /* We need to do this in case bridge itself got configured properly, but devices behind it failed */
                                                                func->bus = 1; /* To indicate to the unconfigure function that this is a PPB */
                                                                cleanup_count = 2;
                                                                goto error;
                                                        }
                                                        flag = 1;
                                                }
                                        }

                                        newfunc = kzalloc(sizeof(*newfunc), GFP_KERNEL);
                                        if (!newfunc)
                                                return -ENOMEM;

                                        newfunc->busno = cur_func->busno;
                                        newfunc->device = device;
                                        for (j = 0; j < 4; j++)
                                                newfunc->irq[j] = cur_func->irq[j];
                                        for (prev_func = cur_func; prev_func->next; prev_func = prev_func->next);
                                        prev_func->next = newfunc;
                                        cur_func = newfunc;
                                        break;
                                case PCI_HEADER_TYPE_BRIDGE:
                                        class >>= 8;
                                        debug("class now is %x\n", class);
                                        if (class != PCI_CLASS_BRIDGE_PCI) {
                                                err("This %x is not PCI-to-PCI bridge, and as is not supported for hot-plugging.  Please insert another card.\n",
                                                     cur_func->device);
                                                return -ENODEV;
                                        }

                                        assign_alt_irq(cur_func, class_code);

                                        debug("cur_func->busno b4 configure_bridge is %x\n", cur_func->busno);
                                        rc = configure_bridge(&cur_func, slotno);
                                        if (rc == -ENODEV) {
                                                err("You chose to insert Single Bridge, or nested bridges, this is not supported...\n");
                                                err("Bus %x, devfunc %x\n", cur_func->busno, cur_func->device);
                                                return rc;
                                        }
                                        if (rc) {
                                                /* We need to do this in case some other BARs were properly inserted */
                                                func->bus = 1; /* To indicate to the unconfigure function that this is a PPB */
                                                err("was not able to hot-add PPB properly.\n");
                                                cleanup_count = 2;
                                                goto error;
                                        }
                                        debug("cur_func->busno = %x, device = %x, function = %x\n",
                                                cur_func->busno, device, function);
                                        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_SECONDARY_BUS, &sec_number);
                                        debug("after configuring bridge..., sec_number = %x\n", sec_number);
                                        flag = 0;
                                        for (i = 0; i < 32; i++) {
                                                if (func->devices[i]) {
                                                        debug("inside for loop, device is %x\n", i);
                                                        newfunc = kzalloc(sizeof(*newfunc), GFP_KERNEL);
                                                        if (!newfunc)
                                                                return -ENOMEM;

                                                        newfunc->busno = sec_number;
                                                        newfunc->device = (u8) i;
                                                        for (j = 0; j < 4; j++)
                                                                newfunc->irq[j] = cur_func->irq[j];

                                                        if (flag) {
                                                                for (prev_func = cur_func; prev_func->next; prev_func = prev_func->next);
                                                                prev_func->next = newfunc;
                                                        } else
                                                                cur_func->next = newfunc;

                                                        rc = ibmphp_configure_card(newfunc, slotno);

                                                        /* Again, this case should not happen... For complete paranoia, will need to call remove_bus */
                                                        if (rc) {
                                                                /* We need to do this in case some other BARs were properly inserted */
                                                                func->bus = 1; /* To indicate to the unconfigure function that this is a PPB */
                                                                cleanup_count = 2;
                                                                goto error;
                                                        }
                                                        flag = 1;
                                                }
                                        }

                                        function = 0x8;
                                        break;
                                default:
                                        err("MAJOR PROBLEM!!!!, header type not supported? %x\n", hdr_type);
                                        return -ENXIO;
                                        break;
                        }       /* end of switch */
                }       /* end of valid device */
        }       /* end of for */

        if (!valid_device) {
                err("Cannot find any valid devices on the card.  Or unable to read from card.\n");
                return -ENODEV;
        }

        return 0;

error:
        for (i = 0; i < cleanup_count; i++) {
                if (cur_func->io[i]) {
                        ibmphp_remove_resource(cur_func->io[i]);
                        cur_func->io[i] = NULL;
                } else if (cur_func->pfmem[i]) {
                        ibmphp_remove_resource(cur_func->pfmem[i]);
                        cur_func->pfmem[i] = NULL;
                } else if (cur_func->mem[i]) {
                        ibmphp_remove_resource(cur_func->mem[i]);
                        cur_func->mem[i] = NULL;
                }
        }
        return rc;
}

/*
 * This function configures the pci BARs of a single device.
 * Input: pointer to the pci_func
 * Output: configured PCI, 0, or error
 */
static int configure_device(struct pci_func *func)
{
        u32 bar[6];
        u32 address[] = {
                PCI_BASE_ADDRESS_0,
                PCI_BASE_ADDRESS_1,
                PCI_BASE_ADDRESS_2,
                PCI_BASE_ADDRESS_3,
                PCI_BASE_ADDRESS_4,
                PCI_BASE_ADDRESS_5,
                0
        };
        u8 irq;
        int count;
        int len[6];
        struct resource_node *io[6];
        struct resource_node *mem[6];
        struct resource_node *mem_tmp;
        struct resource_node *pfmem[6];
        unsigned int devfn;

        debug("%s - inside\n", __func__);

        devfn = PCI_DEVFN(func->device, func->function);
        ibmphp_pci_bus->number = func->busno;

        for (count = 0; address[count]; count++) {      /* for 6 BARs */

                /* not sure if i need this.  per scott, said maybe need * something like this
                   if devices don't adhere 100% to the spec, so don't want to write
                   to the reserved bits

                pcibios_read_config_byte(cur_func->busno, cur_func->device,
                PCI_BASE_ADDRESS_0 + 4 * count, &tmp);
                if (tmp & 0x01) // IO
                        pcibios_write_config_dword(cur_func->busno, cur_func->device,
                        PCI_BASE_ADDRESS_0 + 4 * count, 0xFFFFFFFD);
                else  // Memory
                        pcibios_write_config_dword(cur_func->busno, cur_func->device,
                        PCI_BASE_ADDRESS_0 + 4 * count, 0xFFFFFFFF);
                 */
                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0xFFFFFFFF);
                pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &bar[count]);

                if (!bar[count])        /* This BAR is not implemented */
                        continue;

                debug("Device %x BAR %d wants %x\n", func->device, count, bar[count]);

                if (bar[count] & PCI_BASE_ADDRESS_SPACE_IO) {
                        /* This is IO */
                        debug("inside IO SPACE\n");

                        len[count] = bar[count] & 0xFFFFFFFC;
                        len[count] = ~len[count] + 1;

                        debug("len[count] in IO %x, count %d\n", len[count], count);

                        io[count] = kzalloc(sizeof(struct resource_node), GFP_KERNEL);

                        if (!io[count])
                                return -ENOMEM;

                        io[count]->type = IO;
                        io[count]->busno = func->busno;
                        io[count]->devfunc = PCI_DEVFN(func->device, func->function);
                        io[count]->len = len[count];
                        if (ibmphp_check_resource(io[count], 0) == 0) {
                                ibmphp_add_resource(io[count]);
                                func->io[count] = io[count];
                        } else {
                                err("cannot allocate requested io for bus %x device %x function %x len %x\n",
                                     func->busno, func->device, func->function, len[count]);
                                kfree(io[count]);
                                return -EIO;
                        }
                        pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], func->io[count]->start);

                        /* _______________This is for debugging purposes only_____________________ */
                        debug("b4 writing, the IO address is %x\n", func->io[count]->start);
                        pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &bar[count]);
                        debug("after writing.... the start address is %x\n", bar[count]);
                        /* _________________________________________________________________________*/

                } else {
                        /* This is Memory */
                        if (bar[count] & PCI_BASE_ADDRESS_MEM_PREFETCH) {
                                /* pfmem */
                                debug("PFMEM SPACE\n");

                                len[count] = bar[count] & 0xFFFFFFF0;
                                len[count] = ~len[count] + 1;

                                debug("len[count] in PFMEM %x, count %d\n", len[count], count);

                                pfmem[count] = kzalloc(sizeof(struct resource_node), GFP_KERNEL);
                                if (!pfmem[count])
                                        return -ENOMEM;

                                pfmem[count]->type = PFMEM;
                                pfmem[count]->busno = func->busno;
                                pfmem[count]->devfunc = PCI_DEVFN(func->device,
                                                        func->function);
                                pfmem[count]->len = len[count];
                                pfmem[count]->fromMem = 0;
                                if (ibmphp_check_resource(pfmem[count], 0) == 0) {
                                        ibmphp_add_resource(pfmem[count]);
                                        func->pfmem[count] = pfmem[count];
                                } else {
                                        mem_tmp = kzalloc(sizeof(*mem_tmp), GFP_KERNEL);
                                        if (!mem_tmp) {
                                                kfree(pfmem[count]);
                                                return -ENOMEM;
                                        }
                                        mem_tmp->type = MEM;
                                        mem_tmp->busno = pfmem[count]->busno;
                                        mem_tmp->devfunc = pfmem[count]->devfunc;
                                        mem_tmp->len = pfmem[count]->len;
                                        debug("there's no pfmem... going into mem.\n");
                                        if (ibmphp_check_resource(mem_tmp, 0) == 0) {
                                                ibmphp_add_resource(mem_tmp);
                                                pfmem[count]->fromMem = 1;
                                                pfmem[count]->rangeno = mem_tmp->rangeno;
                                                pfmem[count]->start = mem_tmp->start;
                                                pfmem[count]->end = mem_tmp->end;
                                                ibmphp_add_pfmem_from_mem(pfmem[count]);
                                                func->pfmem[count] = pfmem[count];
                                        } else {
                                                err("cannot allocate requested pfmem for bus %x, device %x, len %x\n",
                                                     func->busno, func->device, len[count]);
                                                kfree(mem_tmp);
                                                kfree(pfmem[count]);
                                                return -EIO;
                                        }
                                }

                                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], func->pfmem[count]->start);

                                /*_______________This is for debugging purposes only______________________________*/
                                debug("b4 writing, start address is %x\n", func->pfmem[count]->start);
                                pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &bar[count]);
                                debug("after writing, start address is %x\n", bar[count]);
                                /*_________________________________________________________________________________*/

                                if (bar[count] & PCI_BASE_ADDRESS_MEM_TYPE_64) {        /* takes up another dword */
                                        debug("inside the mem 64 case, count %d\n", count);
                                        count += 1;
                                        /* on the 2nd dword, write all 0s, since we can't handle them n.e.ways */
                                        pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0x00000000);
                                }
                        } else {
                                /* regular memory */
                                debug("REGULAR MEM SPACE\n");

                                len[count] = bar[count] & 0xFFFFFFF0;
                                len[count] = ~len[count] + 1;

                                debug("len[count] in Mem %x, count %d\n", len[count], count);

                                mem[count] = kzalloc(sizeof(struct resource_node), GFP_KERNEL);
                                if (!mem[count])
                                        return -ENOMEM;

                                mem[count]->type = MEM;
                                mem[count]->busno = func->busno;
                                mem[count]->devfunc = PCI_DEVFN(func->device,
                                                        func->function);
                                mem[count]->len = len[count];
                                if (ibmphp_check_resource(mem[count], 0) == 0) {
                                        ibmphp_add_resource(mem[count]);
                                        func->mem[count] = mem[count];
                                } else {
                                        err("cannot allocate requested mem for bus %x, device %x, len %x\n",
                                             func->busno, func->device, len[count]);
                                        kfree(mem[count]);
                                        return -EIO;
                                }
                                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], func->mem[count]->start);
                                /* _______________________This is for debugging purposes only _______________________*/
                                debug("b4 writing, start address is %x\n", func->mem[count]->start);
                                pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &bar[count]);
                                debug("after writing, the address is %x\n", bar[count]);
                                /* __________________________________________________________________________________*/

                                if (bar[count] & PCI_BASE_ADDRESS_MEM_TYPE_64) {
                                        /* takes up another dword */
                                        debug("inside mem 64 case, reg. mem, count %d\n", count);
                                        count += 1;
                                        /* on the 2nd dword, write all 0s, since we can't handle them n.e.ways */
                                        pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0x00000000);
                                }
                        }
                }               /* end of mem */
        }                       /* end of for */

        func->bus = 0;          /* To indicate that this is not a PPB */
        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_INTERRUPT_PIN, &irq);
        if ((irq > 0x00) && (irq < 0x05))
                pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_INTERRUPT_LINE, func->irq[irq - 1]);

        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_CACHE_LINE_SIZE, CACHE);
        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_LATENCY_TIMER, LATENCY);

        pci_bus_write_config_dword(ibmphp_pci_bus, devfn, PCI_ROM_ADDRESS, 0x00L);
        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_COMMAND, DEVICEENABLE);

        return 0;
}

/******************************************************************************
 * This routine configures a PCI-2-PCI bridge and the functions behind it
 * Parameters: pci_func
 * Returns:
 ******************************************************************************/
static int configure_bridge(struct pci_func **func_passed, u8 slotno)
{
        int count;
        int i;
        int rc;
        u8 sec_number;
        u8 io_base;
        u16 pfmem_base;
        u32 bar[2];
        u32 len[2];
        u8 flag_io = 0;
        u8 flag_mem = 0;
        u8 flag_pfmem = 0;
        u8 need_io_upper = 0;
        u8 need_pfmem_upper = 0;
        struct res_needed *amount_needed = NULL;
        struct resource_node *io = NULL;
        struct resource_node *bus_io[2] = {NULL, NULL};
        struct resource_node *mem = NULL;
        struct resource_node *bus_mem[2] = {NULL, NULL};
        struct resource_node *mem_tmp = NULL;
        struct resource_node *pfmem = NULL;
        struct resource_node *bus_pfmem[2] = {NULL, NULL};
        struct bus_node *bus;
        u32 address[] = {
                PCI_BASE_ADDRESS_0,
                PCI_BASE_ADDRESS_1,
                0
        };
        struct pci_func *func = *func_passed;
        unsigned int devfn;
        u8 irq;
        int retval;

        debug("%s - enter\n", __func__);

        devfn = PCI_DEVFN(func->function, func->device);
        ibmphp_pci_bus->number = func->busno;

        /* Configuring necessary info for the bridge so that we could see the devices
         * behind it
         */

        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_PRIMARY_BUS, func->busno);

        /* _____________________For debugging purposes only __________________________
        pci_bus_config_byte(ibmphp_pci_bus, devfn, PCI_PRIMARY_BUS, &pri_number);
        debug("primary # written into the bridge is %x\n", pri_number);
         ___________________________________________________________________________*/

        /* in EBDA, only get allocated 1 additional bus # per slot */
        sec_number = find_sec_number(func->busno, slotno);
        if (sec_number == 0xff) {
                err("cannot allocate secondary bus number for the bridged device\n");
                return -EINVAL;
        }

        debug("after find_sec_number, the number we got is %x\n", sec_number);
        debug("AFTER FIND_SEC_NUMBER, func->busno IS %x\n", func->busno);

        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_SECONDARY_BUS, sec_number);

        /* __________________For debugging purposes only __________________________________
        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_SECONDARY_BUS, &sec_number);
        debug("sec_number after write/read is %x\n", sec_number);
         ________________________________________________________________________________*/

        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_SUBORDINATE_BUS, sec_number);

        /* __________________For debugging purposes only ____________________________________
        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_SUBORDINATE_BUS, &sec_number);
        debug("subordinate number after write/read is %x\n", sec_number);
         __________________________________________________________________________________*/

        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_CACHE_LINE_SIZE, CACHE);
        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_LATENCY_TIMER, LATENCY);
        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_SEC_LATENCY_TIMER, LATENCY);

        debug("func->busno is %x\n", func->busno);
        debug("sec_number after writing is %x\n", sec_number);


        /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
           !!!!!!!!!!!!!!!NEED TO ADD!!!  FAST BACK-TO-BACK ENABLE!!!!!!!!!!!!!!!!!!!!
           !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*/


        /* First we need to allocate mem/io for the bridge itself in case it needs it */
        for (count = 0; address[count]; count++) {      /* for 2 BARs */
                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0xFFFFFFFF);
                pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &bar[count]);

                if (!bar[count]) {
                        /* This BAR is not implemented */
                        debug("so we come here then, eh?, count = %d\n", count);
                        continue;
                }
                //  tmp_bar = bar[count];

                debug("Bar %d wants %x\n", count, bar[count]);

                if (bar[count] & PCI_BASE_ADDRESS_SPACE_IO) {
                        /* This is IO */
                        len[count] = bar[count] & 0xFFFFFFFC;
                        len[count] = ~len[count] + 1;

                        debug("len[count] in IO = %x\n", len[count]);

                        bus_io[count] = kzalloc(sizeof(struct resource_node), GFP_KERNEL);

                        if (!bus_io[count]) {
                                retval = -ENOMEM;
                                goto error;
                        }
                        bus_io[count]->type = IO;
                        bus_io[count]->busno = func->busno;
                        bus_io[count]->devfunc = PCI_DEVFN(func->device,
                                                        func->function);
                        bus_io[count]->len = len[count];
                        if (ibmphp_check_resource(bus_io[count], 0) == 0) {
                                ibmphp_add_resource(bus_io[count]);
                                func->io[count] = bus_io[count];
                        } else {
                                err("cannot allocate requested io for bus %x, device %x, len %x\n",
                                     func->busno, func->device, len[count]);
                                kfree(bus_io[count]);
                                return -EIO;
                        }

                        pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], func->io[count]->start);

                } else {
                        /* This is Memory */
                        if (bar[count] & PCI_BASE_ADDRESS_MEM_PREFETCH) {
                                /* pfmem */
                                len[count] = bar[count] & 0xFFFFFFF0;
                                len[count] = ~len[count] + 1;

                                debug("len[count] in PFMEM = %x\n", len[count]);

                                bus_pfmem[count] = kzalloc(sizeof(struct resource_node), GFP_KERNEL);
                                if (!bus_pfmem[count]) {
                                        retval = -ENOMEM;
                                        goto error;
                                }
                                bus_pfmem[count]->type = PFMEM;
                                bus_pfmem[count]->busno = func->busno;
                                bus_pfmem[count]->devfunc = PCI_DEVFN(func->device,
                                                        func->function);
                                bus_pfmem[count]->len = len[count];
                                bus_pfmem[count]->fromMem = 0;
                                if (ibmphp_check_resource(bus_pfmem[count], 0) == 0) {
                                        ibmphp_add_resource(bus_pfmem[count]);
                                        func->pfmem[count] = bus_pfmem[count];
                                } else {
                                        mem_tmp = kzalloc(sizeof(*mem_tmp), GFP_KERNEL);
                                        if (!mem_tmp) {
                                                retval = -ENOMEM;
                                                goto error;
                                        }
                                        mem_tmp->type = MEM;
                                        mem_tmp->busno = bus_pfmem[count]->busno;
                                        mem_tmp->devfunc = bus_pfmem[count]->devfunc;
                                        mem_tmp->len = bus_pfmem[count]->len;
                                        if (ibmphp_check_resource(mem_tmp, 0) == 0) {
                                                ibmphp_add_resource(mem_tmp);
                                                bus_pfmem[count]->fromMem = 1;
                                                bus_pfmem[count]->rangeno = mem_tmp->rangeno;
                                                ibmphp_add_pfmem_from_mem(bus_pfmem[count]);
                                                func->pfmem[count] = bus_pfmem[count];
                                        } else {
                                                err("cannot allocate requested pfmem for bus %x, device %x, len %x\n",
                                                     func->busno, func->device, len[count]);
                                                kfree(mem_tmp);
                                                kfree(bus_pfmem[count]);
                                                return -EIO;
                                        }
                                }

                                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], func->pfmem[count]->start);

                                if (bar[count] & PCI_BASE_ADDRESS_MEM_TYPE_64) {
                                        /* takes up another dword */
                                        count += 1;
                                        /* on the 2nd dword, write all 0s, since we can't handle them n.e.ways */
                                        pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0x00000000);

                                }
                        } else {
                                /* regular memory */
                                len[count] = bar[count] & 0xFFFFFFF0;
                                len[count] = ~len[count] + 1;

                                debug("len[count] in Memory is %x\n", len[count]);

                                bus_mem[count] = kzalloc(sizeof(struct resource_node), GFP_KERNEL);
                                if (!bus_mem[count]) {
                                        retval = -ENOMEM;
                                        goto error;
                                }
                                bus_mem[count]->type = MEM;
                                bus_mem[count]->busno = func->busno;
                                bus_mem[count]->devfunc = PCI_DEVFN(func->device,
                                                        func->function);
                                bus_mem[count]->len = len[count];
                                if (ibmphp_check_resource(bus_mem[count], 0) == 0) {
                                        ibmphp_add_resource(bus_mem[count]);
                                        func->mem[count] = bus_mem[count];
                                } else {
                                        err("cannot allocate requested mem for bus %x, device %x, len %x\n",
                                             func->busno, func->device, len[count]);
                                        kfree(bus_mem[count]);
                                        return -EIO;
                                }

                                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], func->mem[count]->start);

                                if (bar[count] & PCI_BASE_ADDRESS_MEM_TYPE_64) {
                                        /* takes up another dword */
                                        count += 1;
                                        /* on the 2nd dword, write all 0s, since we can't handle them n.e.ways */
                                        pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0x00000000);

                                }
                        }
                }               /* end of mem */
        }                       /* end of for  */

        /* Now need to see how much space the devices behind the bridge needed */
        amount_needed = scan_behind_bridge(func, sec_number);
        if (amount_needed == NULL)
                return -ENOMEM;

        ibmphp_pci_bus->number = func->busno;
        debug("after coming back from scan_behind_bridge\n");
        debug("amount_needed->not_correct = %x\n", amount_needed->not_correct);
        debug("amount_needed->io = %x\n", amount_needed->io);
        debug("amount_needed->mem = %x\n", amount_needed->mem);
        debug("amount_needed->pfmem =  %x\n", amount_needed->pfmem);

        if (amount_needed->not_correct) {
                debug("amount_needed is not correct\n");
                for (count = 0; address[count]; count++) {
                        /* for 2 BARs */
                        if (bus_io[count]) {
                                ibmphp_remove_resource(bus_io[count]);
                                func->io[count] = NULL;
                        } else if (bus_pfmem[count]) {
                                ibmphp_remove_resource(bus_pfmem[count]);
                                func->pfmem[count] = NULL;
                        } else if (bus_mem[count]) {
                                ibmphp_remove_resource(bus_mem[count]);
                                func->mem[count] = NULL;
                        }
                }
                kfree(amount_needed);
                return -ENODEV;
        }

        if (!amount_needed->io) {
                debug("it doesn't want IO?\n");
                flag_io = 1;
        } else {
                debug("it wants %x IO behind the bridge\n", amount_needed->io);
                io = kzalloc(sizeof(*io), GFP_KERNEL);

                if (!io) {
                        retval = -ENOMEM;
                        goto error;
                }
                io->type = IO;
                io->busno = func->busno;
                io->devfunc = PCI_DEVFN(func->device, func->function);
                io->len = amount_needed->io;
                if (ibmphp_check_resource(io, 1) == 0) {
                        debug("were we able to add io\n");
                        ibmphp_add_resource(io);
                        flag_io = 1;
                }
        }

        if (!amount_needed->mem) {
                debug("it doesn't want n.e.memory?\n");
                flag_mem = 1;
        } else {
                debug("it wants %x memory behind the bridge\n", amount_needed->mem);
                mem = kzalloc(sizeof(*mem), GFP_KERNEL);
                if (!mem) {
                        retval = -ENOMEM;
                        goto error;
                }
                mem->type = MEM;
                mem->busno = func->busno;
                mem->devfunc = PCI_DEVFN(func->device, func->function);
                mem->len = amount_needed->mem;
                if (ibmphp_check_resource(mem, 1) == 0) {
                        ibmphp_add_resource(mem);
                        flag_mem = 1;
                        debug("were we able to add mem\n");
                }
        }

        if (!amount_needed->pfmem) {
                debug("it doesn't want n.e.pfmem mem?\n");
                flag_pfmem = 1;
        } else {
                debug("it wants %x pfmemory behind the bridge\n", amount_needed->pfmem);
                pfmem = kzalloc(sizeof(*pfmem), GFP_KERNEL);
                if (!pfmem) {
                        retval = -ENOMEM;
                        goto error;
                }
                pfmem->type = PFMEM;
                pfmem->busno = func->busno;
                pfmem->devfunc = PCI_DEVFN(func->device, func->function);
                pfmem->len = amount_needed->pfmem;
                pfmem->fromMem = 0;
                if (ibmphp_check_resource(pfmem, 1) == 0) {
                        ibmphp_add_resource(pfmem);
                        flag_pfmem = 1;
                } else {
                        mem_tmp = kzalloc(sizeof(*mem_tmp), GFP_KERNEL);
                        if (!mem_tmp) {
                                retval = -ENOMEM;
                                goto error;
                        }
                        mem_tmp->type = MEM;
                        mem_tmp->busno = pfmem->busno;
                        mem_tmp->devfunc = pfmem->devfunc;
                        mem_tmp->len = pfmem->len;
                        if (ibmphp_check_resource(mem_tmp, 1) == 0) {
                                ibmphp_add_resource(mem_tmp);
                                pfmem->fromMem = 1;
                                pfmem->rangeno = mem_tmp->rangeno;
                                ibmphp_add_pfmem_from_mem(pfmem);
                                flag_pfmem = 1;
                        }
                }
        }

        debug("b4 if (flag_io && flag_mem && flag_pfmem)\n");
        debug("flag_io = %x, flag_mem = %x, flag_pfmem = %x\n", flag_io, flag_mem, flag_pfmem);

        if (flag_io && flag_mem && flag_pfmem) {
                /* If on bootup, there was a bridged card in this slot,
                 * then card was removed and ibmphp got unloaded and loaded
                 * back again, there's no way for us to remove the bus
                 * struct, so no need to kmalloc, can use existing node
                 */
                bus = ibmphp_find_res_bus(sec_number);
                if (!bus) {
                        bus = kzalloc(sizeof(*bus), GFP_KERNEL);
                        if (!bus) {
                                retval = -ENOMEM;
                                goto error;
                        }
                        bus->busno = sec_number;
                        debug("b4 adding new bus\n");
                        rc = add_new_bus(bus, io, mem, pfmem, func->busno);
                } else if (!(bus->rangeIO) && !(bus->rangeMem) && !(bus->rangePFMem))
                        rc = add_new_bus(bus, io, mem, pfmem, 0xFF);
                else {
                        err("expected bus structure not empty?\n");
                        retval = -EIO;
                        goto error;
                }
                if (rc) {
                        if (rc == -ENOMEM) {
                                ibmphp_remove_bus(bus, func->busno);
                                kfree(amount_needed);
                                return rc;
                        }
                        retval = rc;
                        goto error;
                }
                pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_IO_BASE, &io_base);
                pci_bus_read_config_word(ibmphp_pci_bus, devfn, PCI_PREF_MEMORY_BASE, &pfmem_base);

                if ((io_base & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
                        debug("io 32\n");
                        need_io_upper = 1;
                }
                if ((pfmem_base & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
                        debug("pfmem 64\n");
                        need_pfmem_upper = 1;
                }

                if (bus->noIORanges) {
                        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_IO_BASE, 0x00 | bus->rangeIO->start >> 8);
                        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_IO_LIMIT, 0x00 | bus->rangeIO->end >> 8);

                        /* _______________This is for debugging purposes only ____________________
                        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_IO_BASE, &temp);
                        debug("io_base = %x\n", (temp & PCI_IO_RANGE_TYPE_MASK) << 8);
                        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_IO_LIMIT, &temp);
                        debug("io_limit = %x\n", (temp & PCI_IO_RANGE_TYPE_MASK) << 8);
                         ________________________________________________________________________*/

                        if (need_io_upper) {    /* since can't support n.e.ways */
                                pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_IO_BASE_UPPER16, 0x0000);
                                pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_IO_LIMIT_UPPER16, 0x0000);
                        }
                } else {
                        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_IO_BASE, 0x00);
                        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_IO_LIMIT, 0x00);
                }

                if (bus->noMemRanges) {
                        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_MEMORY_BASE, 0x0000 | bus->rangeMem->start >> 16);
                        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_MEMORY_LIMIT, 0x0000 | bus->rangeMem->end >> 16);

                        /* ____________________This is for debugging purposes only ________________________
                        pci_bus_read_config_word(ibmphp_pci_bus, devfn, PCI_MEMORY_BASE, &temp);
                        debug("mem_base = %x\n", (temp & PCI_MEMORY_RANGE_TYPE_MASK) << 16);
                        pci_bus_read_config_word(ibmphp_pci_bus, devfn, PCI_MEMORY_LIMIT, &temp);
                        debug("mem_limit = %x\n", (temp & PCI_MEMORY_RANGE_TYPE_MASK) << 16);
                         __________________________________________________________________________________*/

                } else {
                        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_MEMORY_BASE, 0xffff);
                        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_MEMORY_LIMIT, 0x0000);
                }
                if (bus->noPFMemRanges) {
                        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_PREF_MEMORY_BASE, 0x0000 | bus->rangePFMem->start >> 16);
                        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_PREF_MEMORY_LIMIT, 0x0000 | bus->rangePFMem->end >> 16);

                        /* __________________________This is for debugging purposes only _______________________
                        pci_bus_read_config_word(ibmphp_pci_bus, devfn, PCI_PREF_MEMORY_BASE, &temp);
                        debug("pfmem_base = %x", (temp & PCI_MEMORY_RANGE_TYPE_MASK) << 16);
                        pci_bus_read_config_word(ibmphp_pci_bus, devfn, PCI_PREF_MEMORY_LIMIT, &temp);
                        debug("pfmem_limit = %x\n", (temp & PCI_MEMORY_RANGE_TYPE_MASK) << 16);
                         ______________________________________________________________________________________*/

                        if (need_pfmem_upper) { /* since can't support n.e.ways */
                                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, PCI_PREF_BASE_UPPER32, 0x00000000);
                                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, PCI_PREF_LIMIT_UPPER32, 0x00000000);
                        }
                } else {
                        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_PREF_MEMORY_BASE, 0xffff);
                        pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_PREF_MEMORY_LIMIT, 0x0000);
                }

                debug("b4 writing control information\n");

                pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_INTERRUPT_PIN, &irq);
                if ((irq > 0x00) && (irq < 0x05))
                        pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_INTERRUPT_LINE, func->irq[irq - 1]);
                /*
                pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_BRIDGE_CONTROL, ctrl);
                pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_BRIDGE_CONTROL, PCI_BRIDGE_CTL_PARITY);
                pci_bus_write_config_byte(ibmphp_pci_bus, devfn, PCI_BRIDGE_CONTROL, PCI_BRIDGE_CTL_SERR);
                 */

                pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_COMMAND, DEVICEENABLE);
                pci_bus_write_config_word(ibmphp_pci_bus, devfn, PCI_BRIDGE_CONTROL, 0x07);
                for (i = 0; i < 32; i++) {
                        if (amount_needed->devices[i]) {

                                debug("device where devices[i] is 1 = %x\n", i);
                                func->devices[i] = 1;
                        }
                }
                func->bus = 1;  /* For unconfiguring, to indicate it's PPB */
                func_passed = &func;
                debug("func->busno b4 returning is %x\n", func->busno);
                debug("func->busno b4 returning in the other structure is %x\n", (*func_passed)->busno);
                kfree(amount_needed);
                return 0;
        } else {
                err("Configuring bridge was unsuccessful...\n");
                mem_tmp = NULL;
                retval = -EIO;
                goto error;
        }

error:
        kfree(amount_needed);
        if (pfmem)
                ibmphp_remove_resource(pfmem);
        if (io)
                ibmphp_remove_resource(io);
        if (mem)
                ibmphp_remove_resource(mem);
        for (i = 0; i < 2; i++) {       /* for 2 BARs */
                if (bus_io[i]) {
                        ibmphp_remove_resource(bus_io[i]);
                        func->io[i] = NULL;
                } else if (bus_pfmem[i]) {
                        ibmphp_remove_resource(bus_pfmem[i]);
                        func->pfmem[i] = NULL;
                } else if (bus_mem[i]) {
                        ibmphp_remove_resource(bus_mem[i]);
                        func->mem[i] = NULL;
                }
        }
        return retval;
}

/*****************************************************************************
 * This function adds up the amount of resources needed behind the PPB bridge
 * and passes it to the configure_bridge function
 * Input: bridge function
 * Output: amount of resources needed
 *****************************************************************************/
static struct res_needed *scan_behind_bridge(struct pci_func *func, u8 busno)
{
        int count, len[6];
        u16 vendor_id;
        u8 hdr_type;
        u8 device, function;
        unsigned int devfn;
        int howmany = 0;        /*this is to see if there are any devices behind the bridge */

        u32 bar[6], class;
        u32 address[] = {
                PCI_BASE_ADDRESS_0,
                PCI_BASE_ADDRESS_1,
                PCI_BASE_ADDRESS_2,
                PCI_BASE_ADDRESS_3,
                PCI_BASE_ADDRESS_4,
                PCI_BASE_ADDRESS_5,
                0
        };
        struct res_needed *amount;

        amount = kzalloc(sizeof(*amount), GFP_KERNEL);
        if (amount == NULL)
                return NULL;

        ibmphp_pci_bus->number = busno;

        debug("the bus_no behind the bridge is %x\n", busno);
        debug("scanning devices behind the bridge...\n");
        for (device = 0; device < 32; device++) {
                amount->devices[device] = 0;
                for (function = 0; function < 8; function++) {
                        devfn = PCI_DEVFN(device, function);

                        pci_bus_read_config_word(ibmphp_pci_bus, devfn, PCI_VENDOR_ID, &vendor_id);

                        if (vendor_id != PCI_VENDOR_ID_NOTVALID) {
                                /* found correct device!!! */
                                howmany++;

                                pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_HEADER_TYPE, &hdr_type);
                                pci_bus_read_config_dword(ibmphp_pci_bus, devfn, PCI_CLASS_REVISION, &class);

                                debug("hdr_type behind the bridge is %x\n", hdr_type);
                                if ((hdr_type & 0x7f) == PCI_HEADER_TYPE_BRIDGE) {
                                        err("embedded bridges not supported for hot-plugging.\n");
                                        amount->not_correct = 1;
                                        return amount;
                                }

                                class >>= 8;    /* to take revision out, class = class.subclass.prog i/f */
                                if (class == PCI_CLASS_NOT_DEFINED_VGA) {
                                        err("The device %x is VGA compatible and as is not supported for hot plugging.  Please choose another device.\n", device);
                                        amount->not_correct = 1;
                                        return amount;
                                } else if (class == PCI_CLASS_DISPLAY_VGA) {
                                        err("The device %x is not supported for hot plugging.  Please choose another device.\n", device);
                                        amount->not_correct = 1;
                                        return amount;
                                }

                                amount->devices[device] = 1;

                                for (count = 0; address[count]; count++) {
                                        /* for 6 BARs */
                                        /*
                                        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, address[count], &tmp);
                                        if (tmp & 0x01) // IO
                                                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0xFFFFFFFD);
                                        else // MEMORY
                                                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0xFFFFFFFF);
                                        */
                                        pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0xFFFFFFFF);
                                        pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &bar[count]);

                                        debug("what is bar[count]? %x, count = %d\n", bar[count], count);

                                        if (!bar[count])        /* This BAR is not implemented */
                                                continue;

                                        //tmp_bar = bar[count];

                                        debug("count %d device %x function %x wants %x resources\n", count, device, function, bar[count]);

                                        if (bar[count] & PCI_BASE_ADDRESS_SPACE_IO) {
                                                /* This is IO */
                                                len[count] = bar[count] & 0xFFFFFFFC;
                                                len[count] = ~len[count] + 1;
                                                amount->io += len[count];
                                        } else {
                                                /* This is Memory */
                                                if (bar[count] & PCI_BASE_ADDRESS_MEM_PREFETCH) {
                                                        /* pfmem */
                                                        len[count] = bar[count] & 0xFFFFFFF0;
                                                        len[count] = ~len[count] + 1;
                                                        amount->pfmem += len[count];
                                                        if (bar[count] & PCI_BASE_ADDRESS_MEM_TYPE_64)
                                                                /* takes up another dword */
                                                                count += 1;

                                                } else {
                                                        /* regular memory */
                                                        len[count] = bar[count] & 0xFFFFFFF0;
                                                        len[count] = ~len[count] + 1;
                                                        amount->mem += len[count];
                                                        if (bar[count] & PCI_BASE_ADDRESS_MEM_TYPE_64) {
                                                                /* takes up another dword */
                                                                count += 1;
                                                        }
                                                }
                                        }
                                }       /* end for */
                        }       /* end if (valid) */
                }       /* end for */
        }       /* end for */

        if (!howmany)
                amount->not_correct = 1;
        else
                amount->not_correct = 0;
        if ((amount->io) && (amount->io < IOBRIDGE))
                amount->io = IOBRIDGE;
        if ((amount->mem) && (amount->mem < MEMBRIDGE))
                amount->mem = MEMBRIDGE;
        if ((amount->pfmem) && (amount->pfmem < MEMBRIDGE))
                amount->pfmem = MEMBRIDGE;
        return amount;
}

/* The following 3 unconfigure_boot_ routines deal with the case when we had the card
 * upon bootup in the system, since we don't allocate func to such case, we need to read
 * the start addresses from pci config space and then find the corresponding entries in
 * our resource lists.  The functions return either 0, -ENODEV, or -1 (general failure)
 * Change: we also call these functions even if we configured the card ourselves (i.e., not
 * the bootup case), since it should work same way
 */
static int unconfigure_boot_device(u8 busno, u8 device, u8 function)
{
        u32 start_address;
        u32 address[] = {
                PCI_BASE_ADDRESS_0,
                PCI_BASE_ADDRESS_1,
                PCI_BASE_ADDRESS_2,
                PCI_BASE_ADDRESS_3,
                PCI_BASE_ADDRESS_4,
                PCI_BASE_ADDRESS_5,
                0
        };
        int count;
        struct resource_node *io;
        struct resource_node *mem;
        struct resource_node *pfmem;
        struct bus_node *bus;
        u32 end_address;
        u32 temp_end;
        u32 size;
        u32 tmp_address;
        unsigned int devfn;

        debug("%s - enter\n", __func__);

        bus = ibmphp_find_res_bus(busno);
        if (!bus) {
                debug("cannot find corresponding bus.\n");
                return -EINVAL;
        }

        devfn = PCI_DEVFN(device, function);
        ibmphp_pci_bus->number = busno;
        for (count = 0; address[count]; count++) {      /* for 6 BARs */
                pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &start_address);

                /* We can do this here, b/c by that time the device driver of the card has been stopped */

                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], 0xFFFFFFFF);
                pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &size);
                pci_bus_write_config_dword(ibmphp_pci_bus, devfn, address[count], start_address);

                debug("start_address is %x\n", start_address);
                debug("busno, device, function %x %x %x\n", busno, device, function);
                if (!size) {
                        /* This BAR is not implemented */
                        debug("is this bar no implemented?, count = %d\n", count);
                        continue;
                }
                tmp_address = start_address;
                if (start_address & PCI_BASE_ADDRESS_SPACE_IO) {
                        /* This is IO */
                        start_address &= PCI_BASE_ADDRESS_IO_MASK;
                        size = size & 0xFFFFFFFC;
                        size = ~size + 1;
                        end_address = start_address + size - 1;
                        if (ibmphp_find_resource(bus, start_address, &io, IO))
                                goto report_search_failure;

                        debug("io->start = %x\n", io->start);
                        temp_end = io->end;
                        start_address = io->end + 1;
                        ibmphp_remove_resource(io);
                        /* This is needed b/c of the old I/O restrictions in the BIOS */
                        while (temp_end < end_address) {
                                if (ibmphp_find_resource(bus, start_address,
                                                         &io, IO))
                                        goto report_search_failure;

                                debug("io->start = %x\n", io->start);
                                temp_end = io->end;
                                start_address = io->end + 1;
                                ibmphp_remove_resource(io);
                        }

                        /* ????????? DO WE NEED TO WRITE ANYTHING INTO THE PCI CONFIG SPACE BACK ?????????? */
                } else {
                        /* This is Memory */
                        if (start_address & PCI_BASE_ADDRESS_MEM_PREFETCH) {
                                /* pfmem */
                                debug("start address of pfmem is %x\n", start_address);
                                start_address &= PCI_BASE_ADDRESS_MEM_MASK;

                                if (ibmphp_find_resource(bus, start_address, &pfmem, PFMEM) < 0) {
                                        err("cannot find corresponding PFMEM resource to remove\n");
                                        return -EIO;
                                }
                                if (pfmem) {
                                        debug("pfmem->start = %x\n", pfmem->start);

                                        ibmphp_remove_resource(pfmem);
                                }
                        } else {
                                /* regular memory */
                                debug("start address of mem is %x\n", start_address);
                                start_address &= PCI_BASE_ADDRESS_MEM_MASK;

                                if (ibmphp_find_resource(bus, start_address, &mem, MEM) < 0) {
                                        err("cannot find corresponding MEM resource to remove\n");
                                        return -EIO;
                                }
                                if (mem) {
                                        debug("mem->start = %x\n", mem->start);

                                        ibmphp_remove_resource(mem);
                                }
                        }
                        if (tmp_address & PCI_BASE_ADDRESS_MEM_TYPE_64) {
                                /* takes up another dword */
                                count += 1;
                        }
                }       /* end of mem */
        }       /* end of for */

        return 0;

report_search_failure:
        err("cannot find corresponding IO resource to remove\n");
        return -EIO;
}

static int unconfigure_boot_bridge(u8 busno, u8 device, u8 function)
{
        int count;
        int bus_no, pri_no, sub_no, sec_no = 0;
        u32 start_address, tmp_address;
        u8 sec_number, sub_number, pri_number;
        struct resource_node *io = NULL;
        struct resource_node *mem = NULL;
        struct resource_node *pfmem = NULL;
        struct bus_node *bus;
        u32 address[] = {
                PCI_BASE_ADDRESS_0,
                PCI_BASE_ADDRESS_1,
                0
        };
        unsigned int devfn;

        devfn = PCI_DEVFN(device, function);
        ibmphp_pci_bus->number = busno;
        bus_no = (int) busno;
        debug("busno is %x\n", busno);
        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_PRIMARY_BUS, &pri_number);
        debug("%s - busno = %x, primary_number = %x\n", __func__, busno, pri_number);

        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_SECONDARY_BUS, &sec_number);
        debug("sec_number is %x\n", sec_number);
        sec_no = (int) sec_number;
        pri_no = (int) pri_number;
        if (pri_no != bus_no) {
                err("primary numbers in our structures and pci config space don't match.\n");
                return -EINVAL;
        }

        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_SUBORDINATE_BUS, &sub_number);
        sub_no = (int) sub_number;
        debug("sub_no is %d, sec_no is %d\n", sub_no, sec_no);
        if (sec_no != sub_number) {
                err("there're more buses behind this bridge.  Hot removal is not supported.  Please choose another card\n");
                return -ENODEV;
        }

        bus = ibmphp_find_res_bus(sec_number);
        if (!bus) {
                err("cannot find Bus structure for the bridged device\n");
                return -EINVAL;
        }
        debug("bus->busno is %x\n", bus->busno);
        debug("sec_number is %x\n", sec_number);

        ibmphp_remove_bus(bus, busno);

        for (count = 0; address[count]; count++) {
                /* for 2 BARs */
                pci_bus_read_config_dword(ibmphp_pci_bus, devfn, address[count], &start_address);

                if (!start_address) {
                        /* This BAR is not implemented */
                        continue;
                }

                tmp_address = start_address;

                if (start_address & PCI_BASE_ADDRESS_SPACE_IO) {
                        /* This is IO */
                        start_address &= PCI_BASE_ADDRESS_IO_MASK;
                        if (ibmphp_find_resource(bus, start_address, &io, IO) < 0) {
                                err("cannot find corresponding IO resource to remove\n");
                                return -EIO;
                        }
                        if (io)
                                debug("io->start = %x\n", io->start);

                        ibmphp_remove_resource(io);

                        /* ????????? DO WE NEED TO WRITE ANYTHING INTO THE PCI CONFIG SPACE BACK ?????????? */
                } else {
                        /* This is Memory */
                        if (start_address & PCI_BASE_ADDRESS_MEM_PREFETCH) {
                                /* pfmem */
                                start_address &= PCI_BASE_ADDRESS_MEM_MASK;
                                if (ibmphp_find_resource(bus, start_address, &pfmem, PFMEM) < 0) {
                                        err("cannot find corresponding PFMEM resource to remove\n");
                                        return -EINVAL;
                                }
                                if (pfmem) {
                                        debug("pfmem->start = %x\n", pfmem->start);

                                        ibmphp_remove_resource(pfmem);
                                }
                        } else {
                                /* regular memory */
                                start_address &= PCI_BASE_ADDRESS_MEM_MASK;
                                if (ibmphp_find_resource(bus, start_address, &mem, MEM) < 0) {
                                        err("cannot find corresponding MEM resource to remove\n");
                                        return -EINVAL;
                                }
                                if (mem) {
                                        debug("mem->start = %x\n", mem->start);

                                        ibmphp_remove_resource(mem);
                                }
                        }
                        if (tmp_address & PCI_BASE_ADDRESS_MEM_TYPE_64) {
                                /* takes up another dword */
                                count += 1;
                        }
                }       /* end of mem */
        }       /* end of for */
        debug("%s - exiting, returning success\n", __func__);
        return 0;
}

static int unconfigure_boot_card(struct slot *slot_cur)
{
        u16 vendor_id;
        u32 class;
        u8 hdr_type;
        u8 device;
        u8 busno;
        u8 function;
        int rc;
        unsigned int devfn;
        u8 valid_device = 0x00; /* To see if we are ever able to find valid device and read it */

        debug("%s - enter\n", __func__);

        device = slot_cur->device;
        busno = slot_cur->bus;

        debug("b4 for loop, device is %x\n", device);
        /* For every function on the card */
        for (function = 0x0; function < 0x08; function++) {
                devfn = PCI_DEVFN(device, function);
                ibmphp_pci_bus->number = busno;

                pci_bus_read_config_word(ibmphp_pci_bus, devfn, PCI_VENDOR_ID, &vendor_id);

                if (vendor_id != PCI_VENDOR_ID_NOTVALID) {
                        /* found correct device!!! */
                        ++valid_device;

                        debug("%s - found correct device\n", __func__);

                        /* header: x x x x x x x x
                         *         | |___________|=> 1=PPB bridge, 0=normal device, 2=CardBus Bridge
                         *         |_=> 0 = single function device, 1 = multi-function device
                         */

                        pci_bus_read_config_byte(ibmphp_pci_bus, devfn, PCI_HEADER_TYPE, &hdr_type);
                        pci_bus_read_config_dword(ibmphp_pci_bus, devfn, PCI_CLASS_REVISION, &class);

                        debug("hdr_type %x, class %x\n", hdr_type, class);
                        class >>= 8;    /* to take revision out, class = class.subclass.prog i/f */
                        if (class == PCI_CLASS_NOT_DEFINED_VGA) {
                                err("The device %x function %x is VGA compatible and is not supported for hot removing.  Please choose another device.\n", device, function);
                                return -ENODEV;
                        } else if (class == PCI_CLASS_DISPLAY_VGA) {
                                err("The device %x function %x is not supported for hot removing.  Please choose another device.\n", device, function);
                                return -ENODEV;
                        }

                        switch (hdr_type) {
                                case PCI_HEADER_TYPE_NORMAL:
                                        rc = unconfigure_boot_device(busno, device, function);
                                        if (rc) {
                                                err("was not able to unconfigure device %x func %x on bus %x. bailing out...\n",
                                                     device, function, busno);
                                                return rc;
                                        }
                                        function = 0x8;
                                        break;
                                case PCI_HEADER_TYPE_MULTIDEVICE:
                                        rc = unconfigure_boot_device(busno, device, function);
                                        if (rc) {
                                                err("was not able to unconfigure device %x func %x on bus %x. bailing out...\n",
                                                     device, function, busno);
                                                return rc;
                                        }
                                        break;
                                case PCI_HEADER_TYPE_BRIDGE:
                                        class >>= 8;
                                        if (class != PCI_CLASS_BRIDGE_PCI) {
                                                err("This device %x function %x is not PCI-to-PCI bridge, and is not supported for hot-removing.  Please try another card.\n", device, function);
                                                return -ENODEV;
                                        }
                                        rc = unconfigure_boot_bridge(busno, device, function);
                                        if (rc != 0) {
                                                err("was not able to hot-remove PPB properly.\n");
                                                return rc;
                                        }

                                        function = 0x8;
                                        break;
                                case PCI_HEADER_TYPE_MULTIBRIDGE:
                                        class >>= 8;
                                        if (class != PCI_CLASS_BRIDGE_PCI) {
                                                err("This device %x function %x is not PCI-to-PCI bridge,  and is not supported for hot-removing.  Please try another card.\n", device, function);
                                                return -ENODEV;
                                        }
                                        rc = unconfigure_boot_bridge(busno, device, function);
                                        if (rc != 0) {
                                                err("was not able to hot-remove PPB properly.\n");
                                                return rc;
                                        }
                                        break;
                                default:
                                        err("MAJOR PROBLEM!!!! Cannot read device's header\n");
                                        return -1;
                                        break;
                        }       /* end of switch */
                }       /* end of valid device */
        }       /* end of for */

        if (!valid_device) {
                err("Could not find device to unconfigure.  Or could not read the card.\n");
                return -1;
        }
        return 0;
}

/*
 * free the resources of the card (multi, single, or bridged)
 * Parameters: slot, flag to say if this is for removing entire module or just
 * unconfiguring the device
 * TO DO:  will probably need to add some code in case there was some resource,
 * to remove it... this is from when we have errors in the configure_card...
 *                      !!!!!!!!!!!!!!!!!!!!!!!!!FOR BUSES!!!!!!!!!!!!
 * Returns: 0, -1, -ENODEV
 */
int ibmphp_unconfigure_card(struct slot **slot_cur, int the_end)
{
        int i;
        int count;
        int rc;
        struct slot *sl = *slot_cur;
        struct pci_func *cur_func = NULL;
        struct pci_func *temp_func;

        debug("%s - enter\n", __func__);

        if (!the_end) {
                /* Need to unconfigure the card */
                rc = unconfigure_boot_card(sl);
                if ((rc == -ENODEV) || (rc == -EIO) || (rc == -EINVAL)) {
                        /* In all other cases, will still need to get rid of func structure if it exists */
                        return rc;
                }
        }

        if (sl->func) {
                cur_func = sl->func;
                while (cur_func) {
                        /* TO DO: WILL MOST LIKELY NEED TO GET RID OF THE BUS STRUCTURE FROM RESOURCES AS WELL */
                        if (cur_func->bus) {
                                /* in other words, it's a PPB */
                                count = 2;
                        } else {
                                count = 6;
                        }

                        for (i = 0; i < count; i++) {
                                if (cur_func->io[i]) {
                                        debug("io[%d] exists\n", i);
                                        if (the_end > 0)
                                                ibmphp_remove_resource(cur_func->io[i]);
                                        cur_func->io[i] = NULL;
                                }
                                if (cur_func->mem[i]) {
                                        debug("mem[%d] exists\n", i);
                                        if (the_end > 0)
                                                ibmphp_remove_resource(cur_func->mem[i]);
                                        cur_func->mem[i] = NULL;
                                }
                                if (cur_func->pfmem[i]) {
                                        debug("pfmem[%d] exists\n", i);
                                        if (the_end > 0)
                                                ibmphp_remove_resource(cur_func->pfmem[i]);
                                        cur_func->pfmem[i] = NULL;
                                }
                        }

                        temp_func = cur_func->next;
                        kfree(cur_func);
                        cur_func = temp_func;
                }
        }

        sl->func = NULL;
        *slot_cur = sl;
        debug("%s - exit\n", __func__);
        return 0;
}

/*
 * add a new bus resulting from hot-plugging a PPB bridge with devices
 *
 * Input: bus and the amount of resources needed (we know we can assign those,
 *        since they've been checked already
 * Output: bus added to the correct spot
 *         0, -1, error
 */
static int add_new_bus(struct bus_node *bus, struct resource_node *io, struct resource_node *mem, struct resource_node *pfmem, u8 parent_busno)
{
        struct range_node *io_range = NULL;
        struct range_node *mem_range = NULL;
        struct range_node *pfmem_range = NULL;
        struct bus_node *cur_bus = NULL;

        /* Trying to find the parent bus number */
        if (parent_busno != 0xFF) {
                cur_bus = ibmphp_find_res_bus(parent_busno);
                if (!cur_bus) {
                        err("strange, cannot find bus which is supposed to be at the system... something is terribly wrong...\n");
                        return -ENODEV;
                }

                list_add(&bus->bus_list, &cur_bus->bus_list);
        }
        if (io) {
                io_range = kzalloc(sizeof(*io_range), GFP_KERNEL);
                if (!io_range)
                        return -ENOMEM;

                io_range->start = io->start;
                io_range->end = io->end;
                io_range->rangeno = 1;
                bus->noIORanges = 1;
                bus->rangeIO = io_range;
        }
        if (mem) {
                mem_range = kzalloc(sizeof(*mem_range), GFP_KERNEL);
                if (!mem_range)
                        return -ENOMEM;

                mem_range->start = mem->start;
                mem_range->end = mem->end;
                mem_range->rangeno = 1;
                bus->noMemRanges = 1;
                bus->rangeMem = mem_range;
        }
        if (pfmem) {
                pfmem_range = kzalloc(sizeof(*pfmem_range), GFP_KERNEL);
                if (!pfmem_range)
                        return -ENOMEM;

                pfmem_range->start = pfmem->start;
                pfmem_range->end = pfmem->end;
                pfmem_range->rangeno = 1;
                bus->noPFMemRanges = 1;
                bus->rangePFMem = pfmem_range;
        }
        return 0;
}

/*
 * find the 1st available bus number for PPB to set as its secondary bus
 * Parameters: bus_number of the primary bus
 * Returns: bus_number of the secondary bus or 0xff in case of failure
 */
static u8 find_sec_number(u8 primary_busno, u8 slotno)
{
        int min, max;
        u8 busno;
        struct bus_info *bus;
        struct bus_node *bus_cur;

        bus = ibmphp_find_same_bus_num(primary_busno);
        if (!bus) {
                err("cannot get slot range of the bus from the BIOS\n");
                return 0xff;
        }
        max = bus->slot_max;
        min = bus->slot_min;
        if ((slotno > max) || (slotno < min)) {
                err("got the wrong range\n");
                return 0xff;
        }
        busno = (u8) (slotno - (u8) min);
        busno += primary_busno + 0x01;
        bus_cur = ibmphp_find_res_bus(busno);
        /* either there is no such bus number, or there are no ranges, which
         * can only happen if we removed the bridged device in previous load
         * of the driver, and now only have the skeleton bus struct
         */
        if ((!bus_cur) || (!(bus_cur->rangeIO) && !(bus_cur->rangeMem) && !(bus_cur->rangePFMem)))
                return busno;
        return 0xff;
}