266 lines
7.2 KiB
C
266 lines
7.2 KiB
C
/*
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* Routines for tracking a legacy ISA bridge
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*
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* Copyrigh 2007 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
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*
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* Some bits and pieces moved over from pci_64.c
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*
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* Copyrigh 2003 Anton Blanchard <anton@au.ibm.com>, IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#define DEBUG
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/string.h>
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#include <linux/export.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/notifier.h>
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#include <asm/processor.h>
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#include <asm/io.h>
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#include <asm/prom.h>
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#include <asm/pci-bridge.h>
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#include <asm/machdep.h>
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#include <asm/ppc-pci.h>
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unsigned long isa_io_base; /* NULL if no ISA bus */
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EXPORT_SYMBOL(isa_io_base);
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/* Cached ISA bridge dev. */
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static struct device_node *isa_bridge_devnode;
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struct pci_dev *isa_bridge_pcidev;
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EXPORT_SYMBOL_GPL(isa_bridge_pcidev);
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#define ISA_SPACE_MASK 0x1
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#define ISA_SPACE_IO 0x1
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static void pci_process_ISA_OF_ranges(struct device_node *isa_node,
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unsigned long phb_io_base_phys)
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{
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/* We should get some saner parsing here and remove these structs */
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struct pci_address {
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u32 a_hi;
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u32 a_mid;
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u32 a_lo;
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};
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struct isa_address {
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u32 a_hi;
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u32 a_lo;
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};
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struct isa_range {
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struct isa_address isa_addr;
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struct pci_address pci_addr;
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unsigned int size;
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};
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const struct isa_range *range;
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unsigned long pci_addr;
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unsigned int isa_addr;
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unsigned int size;
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int rlen = 0;
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range = of_get_property(isa_node, "ranges", &rlen);
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if (range == NULL || (rlen < sizeof(struct isa_range)))
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goto inval_range;
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/* From "ISA Binding to 1275"
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* The ranges property is laid out as an array of elements,
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* each of which comprises:
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* cells 0 - 1: an ISA address
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* cells 2 - 4: a PCI address
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* (size depending on dev->n_addr_cells)
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* cell 5: the size of the range
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*/
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if ((range->isa_addr.a_hi & ISA_SPACE_MASK) != ISA_SPACE_IO) {
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range++;
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rlen -= sizeof(struct isa_range);
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if (rlen < sizeof(struct isa_range))
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goto inval_range;
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}
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if ((range->isa_addr.a_hi & ISA_SPACE_MASK) != ISA_SPACE_IO)
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goto inval_range;
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isa_addr = range->isa_addr.a_lo;
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pci_addr = (unsigned long) range->pci_addr.a_mid << 32 |
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range->pci_addr.a_lo;
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/* Assume these are both zero. Note: We could fix that and
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* do a proper parsing instead ... oh well, that will do for
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* now as nobody uses fancy mappings for ISA bridges
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*/
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if ((pci_addr != 0) || (isa_addr != 0)) {
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printk(KERN_ERR "unexpected isa to pci mapping: %s\n",
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__func__);
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return;
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}
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/* Align size and make sure it's cropped to 64K */
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size = PAGE_ALIGN(range->size);
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if (size > 0x10000)
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size = 0x10000;
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__ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE,
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size, _PAGE_NO_CACHE|_PAGE_GUARDED);
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return;
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inval_range:
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printk(KERN_ERR "no ISA IO ranges or unexpected isa range, "
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"mapping 64k\n");
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__ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE,
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0x10000, _PAGE_NO_CACHE|_PAGE_GUARDED);
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}
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/**
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* isa_bridge_find_early - Find and map the ISA IO space early before
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* main PCI discovery. This is optionally called by
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* the arch code when adding PCI PHBs to get early
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* access to ISA IO ports
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*/
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void __init isa_bridge_find_early(struct pci_controller *hose)
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{
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struct device_node *np, *parent = NULL, *tmp;
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/* If we already have an ISA bridge, bail off */
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if (isa_bridge_devnode != NULL)
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return;
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/* For each "isa" node in the system. Note : we do a search by
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* type and not by name. It might be better to do by name but that's
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* what the code used to do and I don't want to break too much at
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* once. We can look into changing that separately
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*/
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for_each_node_by_type(np, "isa") {
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/* Look for our hose being a parent */
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for (parent = of_get_parent(np); parent;) {
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if (parent == hose->dn) {
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of_node_put(parent);
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break;
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}
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tmp = parent;
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parent = of_get_parent(parent);
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of_node_put(tmp);
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}
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if (parent != NULL)
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break;
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}
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if (np == NULL)
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return;
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isa_bridge_devnode = np;
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/* Now parse the "ranges" property and setup the ISA mapping */
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pci_process_ISA_OF_ranges(np, hose->io_base_phys);
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/* Set the global ISA io base to indicate we have an ISA bridge */
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isa_io_base = ISA_IO_BASE;
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pr_debug("ISA bridge (early) is %s\n", np->full_name);
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}
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/**
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* isa_bridge_find_late - Find and map the ISA IO space upon discovery of
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* a new ISA bridge
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*/
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static void isa_bridge_find_late(struct pci_dev *pdev,
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struct device_node *devnode)
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{
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struct pci_controller *hose = pci_bus_to_host(pdev->bus);
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/* Store ISA device node and PCI device */
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isa_bridge_devnode = of_node_get(devnode);
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isa_bridge_pcidev = pdev;
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/* Now parse the "ranges" property and setup the ISA mapping */
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pci_process_ISA_OF_ranges(devnode, hose->io_base_phys);
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/* Set the global ISA io base to indicate we have an ISA bridge */
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isa_io_base = ISA_IO_BASE;
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pr_debug("ISA bridge (late) is %s on %s\n",
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devnode->full_name, pci_name(pdev));
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}
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/**
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* isa_bridge_remove - Remove/unmap an ISA bridge
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*/
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static void isa_bridge_remove(void)
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{
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pr_debug("ISA bridge removed !\n");
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/* Clear the global ISA io base to indicate that we have no more
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* ISA bridge. Note that drivers don't quite handle that, though
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* we should probably do something about it. But do we ever really
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* have ISA bridges being removed on machines using legacy devices ?
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*/
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isa_io_base = ISA_IO_BASE;
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/* Clear references to the bridge */
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of_node_put(isa_bridge_devnode);
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isa_bridge_devnode = NULL;
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isa_bridge_pcidev = NULL;
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/* Unmap the ISA area */
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__iounmap_at((void *)ISA_IO_BASE, 0x10000);
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}
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/**
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* isa_bridge_notify - Get notified of PCI devices addition/removal
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*/
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static int isa_bridge_notify(struct notifier_block *nb, unsigned long action,
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void *data)
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{
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struct device *dev = data;
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struct pci_dev *pdev = to_pci_dev(dev);
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struct device_node *devnode = pci_device_to_OF_node(pdev);
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switch(action) {
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case BUS_NOTIFY_ADD_DEVICE:
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/* Check if we have an early ISA device, without PCI dev */
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if (isa_bridge_devnode && isa_bridge_devnode == devnode &&
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!isa_bridge_pcidev) {
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pr_debug("ISA bridge PCI attached: %s\n",
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pci_name(pdev));
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isa_bridge_pcidev = pdev;
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}
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/* Check if we have no ISA device, and this happens to be one,
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* register it as such if it has an OF device
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*/
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if (!isa_bridge_devnode && devnode && devnode->type &&
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!strcmp(devnode->type, "isa"))
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isa_bridge_find_late(pdev, devnode);
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return 0;
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case BUS_NOTIFY_DEL_DEVICE:
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/* Check if this our existing ISA device */
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if (pdev == isa_bridge_pcidev ||
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(devnode && devnode == isa_bridge_devnode))
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isa_bridge_remove();
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return 0;
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}
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return 0;
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}
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static struct notifier_block isa_bridge_notifier = {
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.notifier_call = isa_bridge_notify
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};
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/**
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* isa_bridge_init - register to be notified of ISA bridge addition/removal
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*
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*/
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static int __init isa_bridge_init(void)
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{
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bus_register_notifier(&pci_bus_type, &isa_bridge_notifier);
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return 0;
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}
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arch_initcall(isa_bridge_init);
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