[deliverable/linux.git] / arch / x86 / pci / legacy.c

/*
 * legacy.c - traditional, old school PCI bus probing
 */
#include <linux/init.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <asm/pci_x86.h>

/*
 * Discover remaining PCI buses in case there are peer host bridges.
 * We use the number of last PCI bus provided by the PCI BIOS.
 */
static void pcibios_fixup_peer_bridges(void)
{
	int n;

	if (pcibios_last_bus <= 0 || pcibios_last_bus > 0xff)
		return;
	DBG("PCI: Peer bridge fixup\n");

	for (n=0; n <= pcibios_last_bus; n++)
		pcibios_scan_specific_bus(n);
}

int __init pci_legacy_init(void)
{
	if (!raw_pci_ops) {
		printk("PCI: System does not support PCI\n");
		return 0;
	}

	printk("PCI: Probing PCI hardware\n");
	pcibios_scan_root(0);
	return 0;
}

void pcibios_scan_specific_bus(int busn)
{
	int devfn;
	u32 l;

	if (pci_find_bus(0, busn))
		return;

	for (devfn = 0; devfn < 256; devfn += 8) {
		if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) &&
		    l != 0x0000 && l != 0xffff) {
			DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l);
			printk(KERN_INFO "PCI: Discovered peer bus %02x\n", busn);
			pcibios_scan_root(busn);
			return;
		}
	}
}
EXPORT_SYMBOL_GPL(pcibios_scan_specific_bus);

static int __init pci_subsys_init(void)
{
	/*
	 * The init function returns an non zero value when
	 * pci_legacy_init should be invoked.
	 */
	if (x86_init.pci.init())
		pci_legacy_init();

	pcibios_fixup_peer_bridges();
	x86_init.pci.init_irq();
	pcibios_init();

	return 0;
}
subsys_initcall(pci_subsys_init);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* legacy.c - traditional, old school PCI bus probing
	3	*/
	4	#include <linux/init.h>
69c60c88	5	#include <linux/export.h>
1da177e4	6	#include <linux/pci.h>
82487711	7	#include <asm/pci_x86.h>
1da177e4 LT	8
	9	/*
	10	* Discover remaining PCI buses in case there are peer host bridges.
	11	* We use the number of last PCI bus provided by the PCI BIOS.
	12	*/
a18e3690	13	static void pcibios_fixup_peer_bridges(void)
1da177e4	14	{
5707b24a	15	int n;
1da177e4	16
9dd1e9eb	17	if (pcibios_last_bus <= 0 \|\| pcibios_last_bus > 0xff)
1da177e4 LT	18	return;
	19	DBG("PCI: Peer bridge fixup\n");
	20
5707b24a AR	21	for (n=0; n <= pcibios_last_bus; n++)
5707b24a AR	22	pcibios_scan_specific_bus(n);
1da177e4 LT	23	}
1da177e4 LT	24
b72d0db9	25	int __init pci_legacy_init(void)
1da177e4 LT	26	{
	27	if (!raw_pci_ops) {
	28	printk("PCI: System does not support PCI\n");
	29	return 0;
	30	}
	31
1da177e4	32	printk("PCI: Probing PCI hardware\n");
b7869ba1	33	pcibios_scan_root(0);
1da177e4 LT	34	return 0;
1da177e4 LT	35	}
5707b24a	36
a18e3690	37	void pcibios_scan_specific_bus(int busn)
5707b24a AR	38	{
5707b24a AR	39	int devfn;
5707b24a AR	40	u32 l;
	41
	42	if (pci_find_bus(0, busn))
	43	return;
	44
5707b24a AR	45	for (devfn = 0; devfn < 256; devfn += 8) {
	46	if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) &&
	47	l != 0x0000 && l != 0xffff) {
	48	DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l);
	49	printk(KERN_INFO "PCI: Discovered peer bus %02x\n", busn);
3d2a3661	50	pcibios_scan_root(busn);
5707b24a AR	51	return;
	52	}
	53	}
	54	}
d1fd4fb6	55	EXPORT_SYMBOL_GPL(pcibios_scan_specific_bus);
1da177e4	56
68d0d979	57	static int __init pci_subsys_init(void)
8dd779b1	58	{
b72d0db9 TG	59	/*
	60	* The init function returns an non zero value when
	61	* pci_legacy_init should be invoked.
	62	*/
	63	if (x86_init.pci.init())
	64	pci_legacy_init();
	65
e42d1fe8	66	pcibios_fixup_peer_bridges();
ab3b3793	67	x86_init.pci.init_irq();
8dd779b1	68	pcibios_init();
3a62ed73 RR	69
3a62ed73 RR	70	return 0;
8dd779b1 RR	71	}
8dd779b1 RR	72	subsys_initcall(pci_subsys_init);