Skip to content
Snippets Groups Projects
  • Linus Torvalds's avatar
    755528c8
    Ignore disabled ROM resources at setup · 755528c8
    Linus Torvalds authored
    
    Writing even a disabled value seems to mess up some matrox graphics
    cards.  It may be a card-related issue, but we may also be writing
    reserved low bits in the result.
    
    This was a fall-out of switching x86 over to the generic PCI resource
    allocation code, and needs more debugging.  In particular, the old x86
    code defaulted to not doing any resource allocations at all for ROM
    resources.
    
    In the meantime, this has been reported to make X happier by Helge
    Hafting <helgehaf@aitel.hist.no>.
    
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    755528c8
    History
    Ignore disabled ROM resources at setup
    Linus Torvalds authored
    
    Writing even a disabled value seems to mess up some matrox graphics
    cards.  It may be a card-related issue, but we may also be writing
    reserved low bits in the result.
    
    This was a fall-out of switching x86 over to the generic PCI resource
    allocation code, and needs more debugging.  In particular, the old x86
    code defaulted to not doing any resource allocations at all for ROM
    resources.
    
    In the meantime, this has been reported to make X happier by Helge
    Hafting <helgehaf@aitel.hist.no>.
    
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
setup-res.c 5.39 KiB
/*
 *	drivers/pci/setup-res.c
 *
 * Extruded from code written by
 *      Dave Rusling (david.rusling@reo.mts.dec.com)
 *      David Mosberger (davidm@cs.arizona.edu)
 *	David Miller (davem@redhat.com)
 *
 * Support routines for initializing a PCI subsystem.
 */

/* fixed for multiple pci buses, 1999 Andrea Arcangeli <andrea@suse.de> */

/*
 * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
 *	     Resource sorting
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/cache.h>
#include <linux/slab.h>
#include "pci.h"


static void
pci_update_resource(struct pci_dev *dev, struct resource *res, int resno)
{
	struct pci_bus_region region;
	u32 new, check, mask;
	int reg;

	/* Ignore resources for unimplemented BARs and unused resource slots
	   for 64 bit BARs. */
	if (!res->flags)
		return;

	pcibios_resource_to_bus(dev, &region, res);

	pr_debug("  got res [%lx:%lx] bus [%lx:%lx] flags %lx for "
		 "BAR %d of %s\n", res->start, res->end,
		 region.start, region.end, res->flags, resno, pci_name(dev));

	new = region.start | (res->flags & PCI_REGION_FLAG_MASK);
	if (res->flags & IORESOURCE_IO)
		mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
	else
		mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;

	if (resno < 6) {
		reg = PCI_BASE_ADDRESS_0 + 4 * resno;
	} else if (resno == PCI_ROM_RESOURCE) {
		if (!(res->flags & IORESOURCE_ROM_ENABLE))
			return;
		new |= PCI_ROM_ADDRESS_ENABLE;
		reg = dev->rom_base_reg;
	} else {
		/* Hmm, non-standard resource. */
	
		return;		/* kill uninitialised var warning */
	}

	pci_write_config_dword(dev, reg, new);
	pci_read_config_dword(dev, reg, &check);

	if ((new ^ check) & mask) {
		printk(KERN_ERR "PCI: Error while updating region "
		       "%s/%d (%08x != %08x)\n", pci_name(dev), resno,
		       new, check);
	}

	if ((new & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
	    (PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64)) {
		new = region.start >> 16 >> 16;
		pci_write_config_dword(dev, reg + 4, new);
		pci_read_config_dword(dev, reg + 4, &check);
		if (check != new) {
			printk(KERN_ERR "PCI: Error updating region "
			       "%s/%d (high %08x != %08x)\n",
			       pci_name(dev), resno, new, check);
		}
	}
	res->flags &= ~IORESOURCE_UNSET;
	pr_debug("PCI: moved device %s resource %d (%lx) to %x\n",
		pci_name(dev), resno, res->flags,
		new & ~PCI_REGION_FLAG_MASK);
}

int __devinit
pci_claim_resource(struct pci_dev *dev, int resource)
{
	struct resource *res = &dev->resource[resource];
	struct resource *root = NULL;
	char *dtype = resource < PCI_BRIDGE_RESOURCES ? "device" : "bridge";
	int err;

	if (res->flags & IORESOURCE_IO)
		root = &ioport_resource;
	if (res->flags & IORESOURCE_MEM)
		root = &iomem_resource;

	err = -EINVAL;
	if (root != NULL)
		err = insert_resource(root, res);

	if (err) {
		printk(KERN_ERR "PCI: %s region %d of %s %s [%lx:%lx]\n",
		       root ? "Address space collision on" :
			      "No parent found for",
		       resource, dtype, pci_name(dev), res->start, res->end);
	}

	return err;
}

int pci_assign_resource(struct pci_dev *dev, int resno)
{
	struct pci_bus *bus = dev->bus;
	struct resource *res = dev->resource + resno;
	unsigned long size, min, align;
	int ret;

	size = res->end - res->start + 1;
	min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
	/* The bridge resources are special, as their
	   size != alignment. Sizing routines return
	   required alignment in the "start" field. */
	align = (resno < PCI_BRIDGE_RESOURCES) ? size : res->start;

	/* First, try exact prefetching match.. */
	ret = pci_bus_alloc_resource(bus, res, size, align, min,
				     IORESOURCE_PREFETCH,
				     pcibios_align_resource, dev);

	if (ret < 0 && (res->flags & IORESOURCE_PREFETCH)) {
		/*
		 * That failed.
		 *
		 * But a prefetching area can handle a non-prefetching
		 * window (it will just not perform as well).
		 */
		ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
					     pcibios_align_resource, dev);
	}

	if (ret) {
		printk(KERN_ERR "PCI: Failed to allocate %s resource #%d:%lx@%lx for %s\n",
		       res->flags & IORESOURCE_IO ? "I/O" : "mem",
		       resno, size, res->start, pci_name(dev));
	} else if (resno < PCI_BRIDGE_RESOURCES) {
		pci_update_resource(dev, res, resno);
	}

	return ret;
}

/* Sort resources by alignment */
void __devinit
pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
{
	int i;

	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
		struct resource *r;
		struct resource_list *list, *tmp;
		unsigned long r_align;

		r = &dev->resource[i];
		r_align = r->end - r->start;
		
		if (!(r->flags) || r->parent)
			continue;
		if (!r_align) {
			printk(KERN_WARNING "PCI: Ignore bogus resource %d "
					    "[%lx:%lx] of %s\n",
					    i, r->start, r->end, pci_name(dev));
			continue;
		}
		r_align = (i < PCI_BRIDGE_RESOURCES) ? r_align + 1 : r->start;
		for (list = head; ; list = list->next) {
			unsigned long align = 0;
			struct resource_list *ln = list->next;
			int idx;

			if (ln) {
				idx = ln->res - &ln->dev->resource[0];
				align = (idx < PCI_BRIDGE_RESOURCES) ?
					ln->res->end - ln->res->start + 1 :
					ln->res->start;
			}
			if (r_align > align) {
				tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
				if (!tmp)
					panic("pdev_sort_resources(): "
					      "kmalloc() failed!\n");
				tmp->next = ln;
				tmp->res = r;
				tmp->dev = dev;
				list->next = tmp;
				break;
			}
		}
	}
}