text: /* ASB2305 PCI resource stuff
   *
   * Copyright (C) 2001 Red Hat, Inc. All Rights Reserved.
   * Written by David Howells (dhowells@redhat.com)
   * - Derived from arch/i386/pci-i386.c
   *   - Copyright 1997--2000 Martin Mares <mj@suse.cz>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public Licence
   * as published by the Free Software Foundation; either version
   * 2 of the Licence, or (at your option) any later version.
   */
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/pci.h>
  #include <linux/init.h>
  #include <linux/ioport.h>
  #include <linux/errno.h>
  #include "pci-asb2305.h"
  
  /*
   * We need to avoid collisions with `mirrored' VGA ports
   * and other strange ISA hardware, so we always want the
   * addresses to be allocated in the 0x000-0x0ff region
   * modulo 0x400.
   *
   * Why? Because some silly external IO cards only decode
   * the low 10 bits of the IO address. The 0x00-0xff region
   * is reserved for motherboard devices that decode all 16
   * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
   * but we want to try to avoid allocating at 0x2900-0x2bff
   * which might have be mirrored at 0x0100-0x03ff..
   */
  resource_size_t pcibios_align_resource(void *data, const struct resource *res,
  				resource_size_t size, resource_size_t align)
  {
  	resource_size_t start = res->start;
  
  #if 0
  	struct pci_dev *dev = data;
  
  	printk(KERN_DEBUG
  	       "### PCIBIOS_ALIGN_RESOURCE(%s,,{%08lx-%08lx,%08lx},%lx)\n",
  	       pci_name(dev),
  	       res->start,
  	       res->end,
  	       res->flags,
  	       size
  	       );
  #endif
  
  	if ((res->flags & IORESOURCE_IO) && (start & 0x300))
  		start = (start + 0x3ff) & ~0x3ff;
  
  	return start;
  }
  
  
  /*
   *  Handle resources of PCI devices.  If the world were perfect, we could
   *  just allocate all the resource regions and do nothing more.  It isn't.
   *  On the other hand, we cannot just re-allocate all devices, as it would
   *  require us to know lots of host bridge internals.  So we attempt to
   *  keep as much of the original configuration as possible, but tweak it
   *  when it's found to be wrong.
   *
   *  Known BIOS problems we have to work around:
   *	- I/O or memory regions not configured
   *	- regions configured, but not enabled in the command register
   *	- bogus I/O addresses above 64K used
   *	- expansion ROMs left enabled (this may sound harmless, but given
   *	  the fact the PCI specs explicitly allow address decoders to be
   *	  shared between expansion ROMs and other resource regions, it's
   *	  at least dangerous)
   *
   *  Our solution:
   *	(1) Allocate resources for all buses behind PCI-to-PCI bridges.
   *	    This gives us fixed barriers on where we can allocate.
   *	(2) Allocate resources for all enabled devices.  If there is
   *	    a collision, just mark the resource as unallocated. Also
   *	    disable expansion ROMs during this step.
   *	(3) Try to allocate resources for disabled devices.  If the
   *	    resources were assigned correctly, everything goes well,
   *	    if they weren't, they won't disturb allocation of other
   *	    resources.
   *	(4) Assign new addresses to resources which were either
   *	    not configured at all or misconfigured.  If explicitly
   *	    requested by the user, configure expansion ROM address
   *	    as well.
   */
  static void __init pcibios_allocate_bus_resources(struct list_head *bus_list)
  {
  	struct pci_bus *bus;
  	struct pci_dev *dev;
  	int idx;
  	struct resource *r;
  
  	/* Depth-First Search on bus tree */
  	list_for_each_entry(bus, bus_list, node) {
  		dev = bus->self;
  		if (dev) {
  			for (idx = PCI_BRIDGE_RESOURCES;
  			     idx < PCI_NUM_RESOURCES;
  			     idx++) {
  				r = &dev->resource[idx];
  				if (!r->flags)
  					continue;
  				if (!r->start ||
  				    pci_claim_bridge_resource(dev, idx) < 0) {
  					printk(KERN_ERR "PCI:"
  					       " Cannot allocate resource"
  					       " region %d of bridge %s\n",
  					       idx, pci_name(dev));
  					/* Something is wrong with the region.
  					 * Invalidate the resource to prevent
  					 * child resource allocations in this
  					 * range. */
  					r->start = r->end = 0;
  					r->flags = 0;
  				}
  			}
  		}
  		pcibios_allocate_bus_resources(&bus->children);
  	}
  }
  
  static void __init pcibios_allocate_resources(int pass)
  {
  	struct pci_dev *dev = NULL;
  	int idx, disabled;
  	u16 command;
  	struct resource *r;
  
  	for_each_pci_dev(dev) {
  		pci_read_config_word(dev, PCI_COMMAND, &command);
  		for (idx = 0; idx < 6; idx++) {
  			r = &dev->resource[idx];
  			if (r->parent)		/* Already allocated */
  				continue;
  			if (!r->start)		/* Address not assigned */
  				continue;
  			if (r->flags & IORESOURCE_IO)
  				disabled = !(command & PCI_COMMAND_IO);
  			else
  				disabled = !(command & PCI_COMMAND_MEMORY);
  			if (pass == disabled) {
  				DBG("PCI[%s]: Resource %08lx-%08lx"
  				    " (f=%lx, d=%d, p=%d)\n",
  				    pci_name(dev), r->start, r->end, r->flags,
  				    disabled, pass);
  				if (pci_claim_resource(dev, idx) < 0) {
  					printk(KERN_ERR "PCI:"
  					       " Cannot allocate resource"
  					       " region %d of device %s\n",
  					       idx, pci_name(dev));
  					/* We'll assign a new address later */
  					r->end -= r->start;
  					r->start = 0;
  				}
  			}
  		}
  		if (!pass) {
  			r = &dev->resource[PCI_ROM_RESOURCE];
  			if (r->flags & IORESOURCE_ROM_ENABLE) {
  				/* Turn the ROM off, leave the resource region,
  				 * but keep it unregistered. */
  				u32 reg;
  				DBG("PCI: Switching off ROM of %s\n",
  				    pci_name(dev));
  				r->flags &= ~IORESOURCE_ROM_ENABLE;
  				pci_read_config_dword(
  					dev, dev->rom_base_reg, &reg);
  				pci_write_config_dword(
  					dev, dev->rom_base_reg,
  					reg & ~PCI_ROM_ADDRESS_ENABLE);
  			}
  		}
  	}
  }
  
  static int __init pcibios_assign_resources(void)
  {
  	struct pci_dev *dev = NULL;
  	struct resource *r;
  
  	/* Try to use BIOS settings for ROMs, otherwise let
  	   pci_assign_unassigned_resources() allocate the new
  	   addresses. */
  	for_each_pci_dev(dev) {
  		r = &dev->resource[PCI_ROM_RESOURCE];
  		if (!r->flags || !r->start)
  			continue;
  		if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) {
  			r->end -= r->start;
  			r->start = 0;
  		}
  	}
  
  	pci_assign_unassigned_resources();
  
  	return 0;
  }
  
  fs_initcall(pcibios_assign_resources);
  
  void __init pcibios_resource_survey(void)
  {
  	DBG("PCI: Allocating resources\n");
  	pcibios_allocate_bus_resources(&pci_root_buses);
  	pcibios_allocate_resources(0);
  	pcibios_allocate_resources(1);
  }
  
  int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
  			enum pci_mmap_state mmap_state, int write_combine)
  {
  	unsigned long prot;
  
  	/* Leave vm_pgoff as-is, the PCI space address is the physical
  	 * address on this platform.
  	 */
  	vma->vm_flags |= VM_LOCKED;
  
  	prot = pgprot_val(vma->vm_page_prot);
  	prot &= ~_PAGE_CACHE;
  	vma->vm_page_prot = __pgprot(prot);
  
  	/* Write-combine setting is ignored */
  	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
  			       vma->vm_end - vma->vm_start,
  			       vma->vm_page_prot))
  		return -EAGAIN;
  
  	return 0;
  }
  