path: root/drivers/pci/setup-bus.c

/*
 *	drivers/pci/setup-bus.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.
 */

/*
 * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
 *	     PCI-PCI bridges cleanup, sorted resource allocation.
 * Feb 2002, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
 *	     Converted to allocation in 3 passes, which gives
 *	     tighter packing. Prefetchable range support.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/cache.h>
#include <linux/slab.h>
#include <asm-generic/pci-bridge.h>
#include "pci.h"

unsigned int pci_flags;

struct pci_dev_resource {
	struct list_head list;
	struct resource *res;
	struct pci_dev *dev;
	resource_size_t start;
	resource_size_t end;
	resource_size_t add_size;
	resource_size_t min_align;
	unsigned long flags;
};

static void free_list(struct list_head *head)
{
	struct pci_dev_resource *dev_res, *tmp;

	list_for_each_entry_safe(dev_res, tmp, head, list) {
		list_del(&dev_res->list);
		kfree(dev_res);
	}
}

/**
 * add_to_list() - add a new resource tracker to the list
 * @head:	Head of the list
 * @dev:	device corresponding to which the resource
 *		belongs
 * @res:	The resource to be tracked
 * @add_size:	additional size to be optionally added
 *              to the resource
 */
static int add_to_list(struct list_head *head,
		 struct pci_dev *dev, struct resource *res,
		 resource_size_t add_size, resource_size_t min_align)
{
	struct pci_dev_resource *tmp;

	tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
	if (!tmp) {
		pr_warning("add_to_list: kmalloc() failed!\n");
		return -ENOMEM;
	}

	tmp->res = res;
	tmp->dev = dev;
	tmp->start = res->start;
	tmp->end = res->end;
	tmp->flags = res->flags;
	tmp->add_size = add_size;
	tmp->min_align = min_align;

	list_add(&tmp->list, head);

	return 0;
}

static void remove_from_list(struct list_head *head,
				 struct resource *res)
{
	struct pci_dev_resource *dev_res, *tmp;

	list_for_each_entry_safe(dev_res, tmp, head, list) {
		if (dev_res->res == res) {
			list_del(&dev_res->list);
			kfree(dev_res);
			break;
		}
	}
}

static resource_size_t get_res_add_size(struct list_head *head,
					struct resource *res)
{
	struct pci_dev_resource *dev_res;

	list_for_each_entry(dev_res, head, list) {
		if (dev_res->res == res) {
			int idx = res - &dev_res->dev->resource[0];

			dev_printk(KERN_DEBUG, &dev_res->dev->dev,
				 "res[%d]=%pR get_res_add_size add_size %llx\n",
				 idx, dev_res->res,
				 (unsigned long long)dev_res->add_size);

			return dev_res->add_size;
		}
	}

	return 0;
}

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

	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
		struct resource *r;
		struct pci_dev_resource *dev_res, *tmp;
		resource_size_t r_align;
		struct list_head *n;

		r = &dev->resource[i];

		if (r->flags & IORESOURCE_PCI_FIXED)
			continue;

		if (!(r->flags) || r->parent)
			continue;

		r_align = pci_resource_alignment(dev, r);
		if (!r_align) {
			dev_warn(&dev->dev, "BAR %d: %pR has bogus alignment\n",
				 i, r);
			continue;
		}

		tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
		if (!tmp)
			panic("pdev_sort_resources(): "
			      "kmalloc() failed!\n");
		tmp->res = r;
		tmp->dev = dev;

		/* fallback is smallest one or list is empty*/
		n = head;
		list_for_each_entry(dev_res, head, list) {
			resource_size_t align;

			align = pci_resource_alignment(dev_res->dev,
							 dev_res->res);

			if (r_align > align) {
				n = &dev_res->list;
				break;
			}
		}
		/* Insert it just before n*/
		list_add_tail(&tmp->list, n);
	}
}

static void __dev_sort_resources(struct pci_dev *dev,
				 struct list_head *head)
{
	u16 class = dev->class >> 8;

	/* Don't touch classless devices or host bridges or ioapics.  */
	if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)
		return;

	/* Don't touch ioapic devices already enabled by firmware */
	if (class == PCI_CLASS_SYSTEM_PIC) {
		u16 command;
		pci_read_config_word(dev, PCI_COMMAND, &command);
		if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
			return;
	}

	pdev_sort_resources(dev, head);
}

static inline void reset_resource(struct resource *res)
{
	res->start = 0;
	res->end = 0;
	res->flags = 0;
}

/**
 * reassign_resources_sorted() - satisfy any additional resource requests
 *
 * @realloc_head : head of the list tracking requests requiring additional
 *             resources
 * @head     : head of the list tracking requests with allocated
 *             resources
 *
 * Walk through each element of the realloc_head and try to procure
 * additional resources for the element, provided the element
 * is in the head list.
 */
static void reassign_resources_sorted(struct list_head *realloc_head,
		struct list_head *head)
{
	struct resource *res;
	struct pci_dev_resource *add_res, *tmp;
	struct pci_dev_resource *dev_res;
	resource_size_t add_size;
	int idx;

	list_for_each_entry_safe(add_res, tmp, realloc_head, list) {
		bool found_match = false;

		res = add_res->res;
		/* skip resource that has been reset */
		if (!res->flags)
			goto out;

		/* skip this resource if not found in head list */
		list_for_each_entry(dev_res, head, list) {
			if (dev_res->res == res) {
				found_match = true;
				break;
			}
		}
		if (!found_match)/* just skip */
			conti