PCI: remove initial bios sort of PCI devices on x86

We currently keep 2 lists of PCI devices in the system, one in the
driver core, and one all on its own.  This second list is sorted at boot
time, in "BIOS" order, to try to remain compatible with older kernels
(2.2 and earlier days).  There was also a "nosort" option to turn this
sorting off, to remain compatible with even older kernel versions, but
that just ends up being what we have been doing from 2.5 days...

Unfortunately, the second list of devices is not really ever used to 
determine the probing order of PCI devices or drivers[1].  That is done
using the driver core list instead.  This change happened back in the
early 2.5 days.

Relying on BIOS ording for the binding of drivers to specific device
names is problematic for many reasons, and userspace tools like udev
exist to properly name devices in a persistant manner if that is needed,
no reliance on the BIOS is needed.

Matt Domsch and others at Dell noticed this back in 2006, and added a
boot option to sort the PCI device lists (both of them) in a
breadth-first manner to help remain compatible with the 2.4 order, if
needed for any reason.  This option is not going away, as some systems
rely on them.

This patch removes the sorting of the internal PCI device list in "BIOS"
mode, as it's not needed at all anymore, and hasn't for many years.
I've also removed the PCI flags for this from some other arches that for
some reason defined them, but never used them.

This should not change the ordering of any drivers or device probing.

[1] The old-style pci_get_device and pci_find_device() still used this
sorting order, but there are very few drivers that use these functions,
as they are deprecated for use in this manner.  If for some reason, a
driver rely on the order and uses these functions, the breadth-first
boot option will resolve any problem.

Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/kernel-parameters.txt

@@ -1461,10 +1461,6 @@ and is between 256 and 4096 characters. It is defined in the file
 		nomsi		[MSI] If the PCI_MSI kernel config parameter is
 				enabled, this kernel boot option can be used to
 				disable the use of MSI interrupts system-wide.
-		nosort		[X86-32] Don't sort PCI devices according to
-				order given by the PCI BIOS. This sorting is
-				done to get a device order compatible with
-				older kernels.
 		biosirq		[X86-32] Use PCI BIOS calls to get the interrupt
 				routing table. These calls are known to be buggy
 				on several machines and they hang the machine

arch/frv/mb93090-mb00/pci-frv.h

@@ -17,8 +17,6 @@
 #define PCI_PROBE_BIOS		0x0001
 #define PCI_PROBE_CONF1		0x0002
 #define PCI_PROBE_CONF2		0x0004
-#define PCI_NO_SORT		0x0100
-#define PCI_BIOS_SORT		0x0200
 #define PCI_NO_CHECKS		0x0400
 #define PCI_ASSIGN_ROMS		0x1000
 #define PCI_BIOS_IRQ_SCAN	0x2000

arch/mn10300/unit-asb2305/pci-asb2305.h

@@ -23,8 +23,6 @@
 #define PCI_PROBE_BIOS 1
 #define PCI_PROBE_CONF1 2
 #define PCI_PROBE_CONF2 4
-#define PCI_NO_SORT 0x100
-#define PCI_BIOS_SORT 0x200
 #define PCI_NO_CHECKS 0x400
 #define PCI_ASSIGN_ROMS 0x1000
 #define PCI_BIOS_IRQ_SCAN 0x2000

arch/sh/drivers/pci/pci-sh4.h

@@ -15,8 +15,6 @@
 #define PCI_PROBE_BIOS		1
 #define PCI_PROBE_CONF1		2
 #define PCI_PROBE_CONF2		4
-#define PCI_NO_SORT		0x100
-#define PCI_BIOS_SORT		0x200
 #define PCI_NO_CHECKS		0x400
 #define PCI_ASSIGN_ROMS		0x1000
 #define PCI_BIOS_IRQ_SCAN	0x2000

arch/x86/pci/common.c

@@ -427,10 +427,6 @@ static int __init pcibios_init(void)
 
 	if (pci_bf_sort >= pci_force_bf)
 		pci_sort_breadthfirst();
-#ifdef CONFIG_PCI_BIOS
-	if ((pci_probe & PCI_BIOS_SORT) && !(pci_probe & PCI_NO_SORT))
-		pcibios_sort();
-#endif
 	return 0;
 }
 
@@ -455,9 +451,6 @@ char * __devinit  pcibios_setup(char *str)
 	} else if (!strcmp(str, "nobios")) {
 		pci_probe &= ~PCI_PROBE_BIOS;
 		return NULL;
-	} else if (!strcmp(str, "nosort")) {
-		pci_probe |= PCI_NO_SORT;
-		return NULL;
 	} else if (!strcmp(str, "biosirq")) {
 		pci_probe |= PCI_BIOS_IRQ_SCAN;
 		return NULL;

arch/x86/pci/pcbios.c

@@ -152,28 +152,6 @@ static int __devinit check_pcibios(void)
 	return 0;
 }
 
-static int __devinit pci_bios_find_device (unsigned short vendor, unsigned short device_id,
-					unsigned short index, unsigned char *bus, unsigned char *device_fn)
-{
-	unsigned short bx;
-	unsigned short ret;
-
-	__asm__("lcall *(%%edi); cld\n\t"
-		"jc 1f\n\t"
-		"xor %%ah, %%ah\n"
-		"1:"
-		: "=b" (bx),
-		  "=a" (ret)
-		: "1" (PCIBIOS_FIND_PCI_DEVICE),
-		  "c" (device_id),
-		  "d" (vendor),
-		  "S" ((int) index),
-		  "D" (&pci_indirect));
-	*bus = (bx >> 8) & 0xff;
-	*device_fn = bx & 0xff;
-	return (int) (ret & 0xff00) >> 8;
-}
-
 static int pci_bios_read(unsigned int seg, unsigned int bus,
 			 unsigned int devfn, int reg, int len, u32 *value)
 {
@@ -363,55 +341,6 @@ static struct pci_raw_ops * __devinit pci_find_bios(void)
 	return NULL;
 }
 
-/*
- * Sort the device list according to PCI BIOS. Nasty hack, but since some
- * fool forgot to define the `correct' device order in the PCI BIOS specs
- * and we want to be (possibly bug-to-bug ;-]) compatible with older kernels
- * which used BIOS ordering, we are bound to do this...
- */
-
-void __devinit pcibios_sort(void)
-{
-	LIST_HEAD(sorted_devices);
-	struct list_head *ln;
-	struct pci_dev *dev, *d;
-	int idx, found;
-	unsigned char bus, devfn;
-
-	DBG("PCI: Sorting device list...\n");
-	while (!list_empty(&pci_devices)) {
-		ln = pci_devices.next;
-		dev = pci_dev_g(ln);
-		idx = found = 0;
-		while (pci_bios_find_device(dev->vendor, dev->device, idx, &bus, &devfn) == PCIBIOS_SUCCESSFUL) {
-			idx++;
-			list_for_each(ln, &pci_devices) {
-				d = pci_dev_g(ln);
-				if (d->bus->number == bus && d->devfn == devfn) {
-					list_move_tail(&d->global_list, &sorted_devices);
-					if (d == dev)
-						found = 1;
-					break;
-				}
-			}
-			if (ln == &pci_devices) {
-				printk(KERN_WARNING "PCI: BIOS reporting unknown device %02x:%02x\n", bus, devfn);
-				/*
-				 * We must not continue scanning as several buggy BIOSes
-				 * return garbage after the last device. Grr.
-				 */
-				break;
-			}
-		}
-		if (!found) {
-			printk(KERN_WARNING "PCI: Device %s not found by BIOS\n",
-				pci_name(dev));
-			list_move_tail(&dev->global_list, &sorted_devices);
-		}
-	}
-	list_splice(&sorted_devices, &pci_devices);
-}
-
 /*
  *  BIOS Functions for IRQ Routing
  */
@@ -495,7 +424,6 @@ void __init pci_pcbios_init(void)
 {
 	if ((pci_probe & PCI_PROBE_BIOS) 
 		&& ((raw_pci_ops = pci_find_bios()))) {
-		pci_probe |= PCI_BIOS_SORT;
 		pci_bios_present = 1;
 	}
 }

arch/x86/pci/pci.h

@@ -19,8 +19,6 @@
 #define PCI_PROBE_MASK		0x000f
 #define PCI_PROBE_NOEARLY	0x0010
 
-#define PCI_NO_SORT		0x0100
-#define PCI_BIOS_SORT		0x0200
 #define PCI_NO_CHECKS		0x0400
 #define PCI_USE_PIRQ_MASK	0x0800
 #define PCI_ASSIGN_ROMS		0x1000
@@ -101,7 +99,6 @@ extern int pci_direct_probe(void);
 extern void pci_direct_init(int type);
 extern void pci_pcbios_init(void);
 extern void pci_mmcfg_init(int type);
-extern void pcibios_sort(void);
 
 /* pci-mmconfig.c */
 

include/asm-sh/mpc1211/pci.h

@@ -24,8 +24,6 @@
 #define PCI_PROBE_BIOS    1
 #define PCI_PROBE_CONF1   2
 #define PCI_PROBE_CONF2   4
-#define PCI_NO_SORT       0x100
-#define PCI_BIOS_SORT     0x200
 #define PCI_NO_CHECKS     0x400
 #define PCI_ASSIGN_ROMS   0x1000
 #define PCI_BIOS_IRQ_SCAN 0x2000