PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.

This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
        -default, BIOS default setting
        -powersave, highest power saving mode, enable all available ASPM
state
and clock power management
        -performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.

In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

There's already a prototype for pci_scan_child_bus() at the correct place in
pci.h, so there's no reason for an additional one.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch fixes the following build error with CONFIG_HOTPLUG=n:

  MODPOST 2137 modules
ERROR: "pci_scan_single_device" [drivers/edac/i82875p_edac.ko] undefined!
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NDoug Thompson <norsk5@yahoo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch removes the following unused exports:
- remove the following unused EXPORT_SYMBOL's:
 - pci-acpi.c: pci_osc_support_set
 - proc.c: pci_proc_detach_bus
- remove the following unused EXPORT_SYMBOL_GPL's:
  - bus.c: pci_walk_bus
  - probe.c: pci_create_bus
  - setup-res.c: pci_claim_resource
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This allows an easier way to get to the device klist associated with a
struct bus_type (you have three to choose from...)  This will make it
easier to move these fields to be dynamic in a future patch.

The only user of this is the PCI core which horribly abuses this
interface to rearrange the order of the pci devices.  This should be
done using the existing bus device walking functions, but that's left
for future patches.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

It appears that some PCI-E bridges do the wrong thing in the presense of
CRS Software Visibility and MMCONFIG.  In particular, it looks like an
ATI bridge (device ID 7936) will return 0001 in the vendor ID field of
any bridged devices indefinitely.

Not enabling CRS SV avoids the problem, and as we currently do not
really make good use of the feature anyway (we just time out rather than
do any threaded discovery as suggested by the CRS specs), we're better
off just not enabling it.

This should fix a slew of problem reports with random devices (generally
graphics adapters or fairly high-performance networking cards, since it
only affected PCI-E) not getting properly recognized on these AMD systems.

If we really want to use CRS-SV, we may end up eventually needing a
whitelist of systems where this should be enabled, along with some kind
of "pcibios_enable_crs()" query to call the system-specific code.
Suggested-by: NLoic Prylli <loic@myri.com>
Tested-by: NKai Ruhnau <kai@tragetaschen.dyndns.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Restore PCI expansion ROM P2P prefetch window creation.

This patch reverts previous "Avoid creating P2P prefetch
window for expansion ROMs" change due to regressions that
were spotted on some systems.
Signed-off-by: NGary Hade <garyhade@us.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This reverts commit fd6e7321, which
helped up things on MIPS, but was wrong for everything else.  As Ralf
Baechle puts it:

  "It seems the whole MIPS resource managment is complicated enough (out
   of necessity) that only a few people actually grok it.  Ioports being
   actually memory mapped on MIPS only makes the confusion worse, sigh."
Requested-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NAlan Cox <alan@redhat.com>
Acked-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When devices are under a p2p bridge, upstream transactions get replaced by the
device id of the bridge as it owns the PCIE transaction.  Hence its necessary
to setup translations on behalf of the bridge as well.  Due to this limitation
all devices under a p2p share the same domain in a DMAR.

We just cache the type of device, if its a native PCIe device
or not for later use.

[akpm@linux-foundation.org: BUG_ON -> WARN_ON+recover]
Signed-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Modify PCI Bridge Control ISA flag for clarity

This patch changes PCI_BRIDGE_CTL_NO_ISA to PCI_BRIDGE_CTL_ISA
and modifies it's clarifying comment and locations where used.
The change reduces the chance of future confusion since it makes
the set/unset meaning of the bit the same in both the bridge
control register and bridge_ctl field of the pci_bus struct.
Signed-off-by: NGary Hade <garyhade@us.ibm.com>
Acked-by: NLinas Vepstas <linas@austin.ibm.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Avoid creating P2P prefetch window for expansion ROMs

Because of the future possibility that P2P prefetch windows will contain
address ranges above 4GB some BIOSes are providing space in the P2P
non-prefetch windows for expansion ROMs.  This is due to expansion ROM
BAR 32-bit limitation.  When expansion ROM BARs without BIOS assigned
address(es) are currently found behind a P2P bridge, the kernel attempts
to create a P2P prefetch window for them even though space for them has
already been provided in the non-prefetch window.  _CRS on some systems
with certain resource conservation conscious BIOSes may not provide the
extra 1MB or more memory resource needed for the expansion ROM motivated
prefetch window causing resource allocation errors.

This change corrects the problem by removing IORESOURCE_PREFETCH from
the expansion ROM flags initialization.  It also removes
IORESOURCE_CACHEABLE which seems inappropriate if only non-cacheable
memory is available.
Signed-off-by: NGary Hade <gary.hade@us.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Skip ISA ioresource alignment on some systems

To conserve limited PCI i/o resource on some IBM multi-node systems, the
BIOS allocates (via _CRS) and expects the kernel to use addresses in
ranges currently excluded by pcibios_align_resource() [i386/pci/i386.c].
This change allows the kernel to use the currently excluded address
ranges on the IBM x3800, x3850, and x3950.
Signed-off-by: NGary Hade <gary.hade@us.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

I got the following error on MIPS Cobalt.

PCI: Unable to reserve I/O region #1:8@f00001f0 for device 0000:00:09.1
pata_via 0000:00:09.1: failed to request/iomap BARs for port 0 (errno=-16)
PCI: Unable to reserve I/O region #3:8@f0000170 for device 0000:00:09.1
pata_via 0000:00:09.1: failed to request/iomap BARs for port 1 (errno=-16)
pata_via 0000:00:09.1: no available native port

The legacy mode IDE resources set the following order.

pci_setup_device()
    Legacy mode ATA controllers have fixed addresses.
    IDE resources: 0x1F0-0x1F7, 0x3F6, 0x170-0x177, 0x376
    |
    V
pcibios_fixup_bus()
    MIPS Cobalt PCI bus regions have the -0x10000000 offset from PCI resources.
    pcibios_fixup_bus() fix PCI bus regions.
    0x1F0 - 0x10000000 = 0xF00001F0
    |
    V
ata_pci_init_one()
    PCI: Unable to reserve I/O region #1:8@f00001f0 for device 0000:00:09.1

In some architectures, PCI bus regions have the offset from PCI resources. 
For this reason, pci_setup_device() should set PCI bus regions to
dev->resource[].

[akpm@linux-foundation.org: use struct initialiser]
Signed-off-by: NYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

On MIPS with PCI && !HOTPLUG, I'm currently getting the following modpost
warning:

  MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x1ce128): Section mismatch: reference to .init.text:pci_read_bridge_bases (between 'pcibios_fixup_bus' and 'pcibios_enable_device')

On MIPS I have the call chains pci_scan_child_bus -> pcibios_fixup_bus ->
pci_read_bridge_bases.  pci_scan_child_bus can't be __devinit because it
it is an exported symbol, thus pcibios_fixup_bus and pci_read_bridge_bases
can't be either.

For some reason I don't see this issue on x86; I blame compiler differences.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Adrian Bunk wrote:
> Alois Nešpor wrote
>> PCI: Bus #0b (-#0e) is hidden behind transparent bridge #0a (-#0b) (try 'pci=assign-busses')
>> Please report the result to linux-kernel to fix this permanently"
>>
>> dmesg:
>> "Yenta: Raising subordinate bus# of parent bus (#0a) from #0b to #0e"
>> without pci=assign-busses and nothing with pci=assign-busses.
> 
> Bernhard?

Ok, lets kill the message. As Alois Nešpor also saw, that's fixed up by Yenta,
so PCI does not have to warn about it. PCI could still warn about it if
is_cardbus is 0 in that instance of pci_scan_bridge(), but so far I have
not seen a report where this would have been the case so I think we can
spare the kernel of that check (removes ~300 lines of asm) unless debugging
is done.

History: The whole check was added in the days before we had the fixup
for this in Yenta and pci=assign-busses was the only way to get CardBus
cards detected on many (not all) of the machines which give this warning.

In theory, there could be cases when this warning would be triggered and
it's not cardbus, then the warning should still apply, but I think this
should only be the case when working on a completely broken PCI setup,
but one may have already enabled the debug code in drivers/pci and the
patched check would then trigger.

I do not sign this off yet because it's completely untested so far, but
everyone is free to test it (with the #ifdef DEBUG replaced by #if 1 and
pr_debug( changed to printk(.

We may also dump the whole check (remove everything within the #ifdef from
the source) if that's perferred.

On Alois Nešpor's machine this would then (only when debugging) this message:

"PCI: Bus #0b (-#0e) is partially hidden behind transparent bridge #0a (-#0b)"

"partially" should be in the message on his machine because #0b of #0b-#0e 
is reachable behind #0a-#0b, but not #0c-#0e.

But that differentiation is now moot anyway because the fixup in Yenta takes
care of it as far as I could see so far, which means that unless somebody
is debugging a totally broken PCI setup, this message is not needed anymore,
not even for debugging PCI.


Ok, here the patch with the following changes:

* Refined to say that the bus is only partially hidden when the parent
  bus numbers are not totally way off (outside of) the child bus range
* remove the reference to pci=assign-busses and the plea to report it

We could add a pure source code-only comment to keep a reference to
pci=assign-busses the in case when this is triggered by someone who
is debugging the cause of this message and looking the way to solve it.

From: Bernhard Kaindl <bk@suse.de>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Before calling init_hwif_default, ide_unregister gets lock ide_lock and
disables irq.  init_hwif_default calls ide_default_io_base which calls
pci_get_device and later pci_get_subsys tries to apply for semaphore
pci_bus_sem and goes to sleep.

Mostly, pci_get_device should be called when irq is turned on.

ide_default_io_base just needs find if list pci_devices is empty.
Signed-off-by: NZhang Yanmin <yanmin.zhang@intel.com>
Cc: Greg KH <greg@kroah.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sysfs is now completely out of driver/module lifetime game.  After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners.  Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.

This patch kills now unnecessary attribute->owner.  Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.

For more info regarding lifetime rule cleanup, please read the
following message.

  http://article.gmane.org/gmane.linux.kernel/510293

(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)
Signed-off-by: NTejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Currently there are 97 occurrences where drivers need the pci
revision ID. We can do this once for all devices. Even the pci
subsystem needs the revision several times for quirks. The extra
u8 member pads out nicely in the pci_dev struct.
Signed-off-by: NAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Back in commit 8c4b2cf9, Bernhard said
that he would fix up all instances of when this message happens.  So
point people at him instead of the linux-kernel list which can not fix
things up.

Cc: Bernhard Kaindl <bk@suse.de>
Cc: Dave Jones <davej@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Miles Lane <miles.lane@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The msi descriptors are linked together with what looks a lot like
a linked list, but isn't a struct list_head list. Make it one.

The only complication is that previously we walked a list of irqs, and
got the descriptor for each with get_irq_msi(). Now we have a list of
descriptors and need to get the irq out of it, so it needs to be in the
actual struct msi_desc. We use 0 to indicate no irq is setup.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Convert code that allocs a struct pci_dev to use alloc_pci_dev().
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

There are currently several places in the kernel where we kmalloc()
a struct pci_dev and start initialising it. It'd be preferable to
have an allocator so we can ensure the pci_dev is correctly initialised
in one place.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Functions marked __devinit will be removed after kernel init.  But being
exported they are potentially called by a module much later.

So the safer choice seems to be to keep the function even in the non
CONFIG_HOTPLUG case.

This silence the follwoing section mismatch warnings:
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_add_device from __ksymtab_gpl between '__ksymtab_pci_bus_add_device' (at offset 0x20) and '__ksymtab_pci_walk_bus'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_create_bus from __ksymtab_gpl between '__ksymtab_pci_create_bus' (at offset 0x40) and '__ksymtab_pci_stop_bus_device'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_max_busnr from __ksymtab_gpl between '__ksymtab_pci_bus_max_busnr' (at offset 0xc0) and '__ksymtab_pci_assign_resource_fixed'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_claim_resource from __ksymtab_gpl between '__ksymtab_pci_claim_resource' (at offset 0xe0) and '__ksymtab_pcie_port_bus_type'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_add_devices from __ksymtab between '__ksymtab_pci_bus_add_devices' (at offset 0x70) and '__ksymtab_pci_bus_alloc_resource'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_scan_bus_parented from __ksymtab between '__ksymtab_pci_scan_bus_parented' (at offset 0x90) and '__ksymtab_pci_root_buses'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_assign_resources from __ksymtab between '__ksymtab_pci_bus_assign_resources' (at offset 0x4d0) and '__ksymtab_pci_bus_size_bridges'
WARNING: drivers/built-in.o - Section mismatch: reference to .init.text:pci_bus_size_bridges from __ksymtab between '__ksymtab_pci_bus_size_bridges' (at offset 0x4e0) and '__ksymtab_pci_setup_cardbus'
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This reverts commit ed8ccee0.

It causes hang on boot for some users and we don't yet know why:

http://bugzilla.kernel.org/show_bug.cgi?id=7562

http://lkml.org/lkml/2007/4/20/404
http://lkml.org/lkml/2007/3/25/113

Just reverse it for 2.6.21-final, having broken X server is somehow
better than unbootable system.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

The change to force legacy mode IDE channels' resources to fixed non-zero
values confuses (at least some versions of) X, because the values reported
by the kernel and those readable from PCI config space aren't consistent
anymore.  Therefore, this patch arranges for the respective BARs to also
get updated if possible.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

pci_scan_msi_device() doesn't do anything anymore, so remove it.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

For pci mem resource that size is bigger than 4G, the sz returned by
pc_size will be 0.
So that resource is skipped, and register contained hi address will be
treated as another 32bit resource. We need to use sz64 and pci_sz64 for
64 bit resource for clear logical.  Typical usages for this: Opteron
system with co-processor and the co-processor could take more than 4G
RAM as pre-fetchable mem resource.
Signed-off-by: NYinghai Lu <yinghai.lu@amd.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Don't have macros between a function's kernel-doc block and the function
definition.  This is not valid for kernel-doc.

Warning(/var/linsrc/linux-2.6.20-rc1-git8//drivers/pci/probe.c:653): No description found for parameter 'IORESOURCE_PCI_FIXED'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Since commit 368c73d4 the kernel will try
to update the non-writeable BAR registers 0..3 of PIIX4 IDE adapters if
pci_assign_unassigned_resources() is used to do full resource assignment of
the bus.  This fails because in the PIIX4 these BAR registers have
implicitly assumed values and read back as zero; it used to work because
the kernel used to just write zero to that register the read back value did
match what was written.

The fix is a new resource flag IORESOURCE_PCI_FIXED used to mark a resource
as non-movable.  This will also be useful to keep other import system
resources from being moved around - for example system consoles on PCI
busses.

[akpm@osdl.org: cleanup]
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

For node-aware skb allocations we need information about the node in struct
net_device or struct device.  Davem suggested to put it into struct device
which this patch does.

In particular:

 - struct device gets a new int numa_node member if CONFIG_NUMA is set
 - there are two new helpers, dev_to_node and set_dev_node to
   transparently deal with the non-numa case
 - for pci devices the node-info is set to the value we get from
   pcibus_to_node.

Note that for some architectures pcibus_to_node doesn't work yet at the time
we call it currently.  This is harmless and will just mean skb allocations
aren't node-local on this architectures until the implementation of
pcibus_to_node on these architectures have been updated (There are patches for
x86 and x86_64 floating around)

[akpm@osdl.org: cleanup]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The number of permutations of crap we do is amazing and almost all of it
has the wrong effect in 2.6.

At the heart of this is the PCI SFF magic which says that compatibility
mode PCI IDE controllers use ISA IRQ routing and hard coded addresses
not the BAR values. The old quirks variously clears them, sets them,
adjusts them and then IDE ignores the result.

In order to drive all this garbage out and to do it portably we need to
handle the SFF rules directly and properly. Because we know the device
BAR 0-3 are not used in compatibility mode we load them with the values
that are implied (and indeed which many controllers actually
thoughtfully put there in this mode anyway).

This removes special cases in the IDE layer and libata which now knows
that bar 0/1/2/3 always contain the correct address. It means our
resource allocation map is accurate from boot, not "mostly accurate"
after ide is loaded, and it shoots lots of code. There is also lots more
code and magic constant knowledge to shoot once this is in and settled.

Been in my test tree for a while both with drivers/ide and with libata.
Wants some -mm shakedown in case I've missed something dumb or there are
corner cases lurking.
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Problem:
New Dell PowerEdge servers have 2 embedded ethernet ports, which are
labeled NIC1 and NIC2 on the chassis, in the BIOS setup screens, and
in the printed documentation.  Assuming no other add-in ethernet ports
in the system, Linux 2.4 kernels name these eth0 and eth1
respectively.  Many people have come to expect this naming.  Linux 2.6
kernels name these eth1 and eth0 respectively (backwards from
expectations).  I also have reports that various Sun and HP servers
have similar behavior.


Root cause:
Linux 2.4 kernels walk the pci_devices list, which happens to be
sorted in breadth-first order (or pcbios_find_device order on i386,
which most often is breadth-first also).  2.6 kernels have both the
pci_devices list and the pci_bus_type.klist_devices list, the latter
is what is walked at driver load time to match the pci_id tables; this
klist happens to be in depth-first order.

On systems where, for physical routing reasons, NIC1 appears on a
lower bus number than NIC2, but NIC2's bridge is discovered first in
the depth-first ordering, NIC2 will be discovered before NIC1.  If the
list were sorted breadth-first, NIC1 would be discovered before NIC2.

A PowerEdge 1955 system has the following topology which easily
exhibits the difference between depth-first and breadth-first device
lists.

-[0000:00]-+-00.0  Intel Corporation 5000P Chipset Memory Controller Hub
           +-02.0-[0000:03-08]--+-00.0-[0000:04-07]--+-00.0-[0000:05-06]----00.0-[0000:06]----00.0  Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC2, 2.4 kernel name eth1, 2.6 kernel name eth0)
           +-1c.0-[0000:01-02]----00.0-[0000:02]----00.0  Broadcom Corporation NetXtreme II BCM5708S Gigabit Ethernet (labeled NIC1, 2.4 kernel name eth0, 2.6 kernel name eth1)


Other factors, such as device driver load order and the presence of
PCI slots at various points in the bus hierarchy further complicate
this problem; I'm not trying to solve those here, just restore the
device order, and thus basic behavior, that 2.4 kernels had.


Solution:

The solution can come in multiple steps.

Suggested fix #1: kernel
Patch below optionally sorts the two device lists into breadth-first
ordering to maintain compatibility with 2.4 kernels.  It adds two new
command line options:
  pci=bfsort
  pci=nobfsort
to force the sort order, or not, as you wish.  It also adds DMI checks
for the specific Dell systems which exhibit "backwards" ordering, to
make them "right".


Suggested fix #2: udev rules from userland
Many people also have the expectation that embedded NICs are always
discovered before add-in NICs (which this patch does not try to do).
Using the PCI IRQ Routing Table provided by system BIOS, it's easy to
determine which PCI devices are embedded, or if add-in, which PCI slot
they're in.  I'm working on a tool that would allow udev to name
ethernet devices in ascending embedded, slot 1 .. slot N order,
subsort by PCI bus/dev/fn breadth-first.  It'll be possible to use it
independent of udev as well for those distributions that don't use
udev in their installers.

Suggested fix #3: system board routing rules
One can constrain the system board layout to put NIC1 ahead of NIC2
regardless of breadth-first or depth-first discovery order.  This adds
a significant level of complexity to board routing, and may not be
possible in all instances (witness the above systems from several
major manufacturers).  I don't want to encourage this particular train
of thought too far, at the expense of not doing #1 or #2 above.


Feedback appreciated.  Patch tested on a Dell PowerEdge 1955 blade
with 2.6.18.

You'll also note I took some liberty and temporarily break the klist
abstraction to simplify and speed up the sort algorithm.  I think
that's both safe and appropriate in this instance.
Signed-off-by: NMatt Domsch <Matt_Domsch@dell.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The pci channel state is currently uninitialized, thus there are two ways
of indicating that "everything's OK": 0 and 1.  This is a bit of a burden.

If a devce driver wants to check if the pci channel is in a working or a
disconnected state, the driver writer must perform checks similar to

   if((pdev->error_state != 0) &&
      (pdev->error_state != pci_channel_io_normal)) {
         whatever();
   }

which is rather akward.  The first check is needed because stuct pci_dev is
inited to all-zeros.  The scond is needed because the error recovery will
set the state to pci_channel_io_normal (which is not zero).

This patch fixes this awkwardness.
Signed-off-by: NLinas Vepstas <linas@austin.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

pci_walk_bus has a race with pci_destroy_dev. When cb is called
in pci_walk_bus, pci_destroy_dev might unlink the dev pointed by next.
Later on in the next loop, pointer next becomes NULL and cause
kernel panic.

Below patch against 2.6.17-rc4 fixes it by changing pci_bus_lock (spin_lock)
to pci_bus_sem (rw_semaphore).
Signed-off-by: NZhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When we detect a 64-bit pre-set address in a BAR on a 32-bit platform,
we disable it and treat it as if it had been unset, thus allowing the
general address assignment code to assign a new address to it when the
device is enabled.  This can happen either if the firmware assigns
64-bit addresses; additionally, some cards have been found "in the
wild" which do not come out of reset with all the BAR registers set to
zero.

Unfortunately, the patch that implemented this tested the low part of
the address instead of the high part of the address.  This patch fixes
that.
Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

[pci] Ignore pre-set 64-bit BARs on 32-bit platforms

Currently, Linux always rejects a device which has a pre-set 64-bit
address on a 32-bit platform.  On systems which do not do PCI
initialization in firmware, this causes some devices which don't
correctly power up with all BARs zero to fail.

This patch makes the kernel automatically zero out such an address
(thus treating it as if it had not been set at all, meaning it will
assign an address if necessary).

I have done this only for devices, not bridges.  It seems potentially
hazardous to do for bridges.
Signed-off-by: NH. Peter Anvin <hpa@c2micro.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

this patch converts drivers/pci to kzalloc usage.
Compile tested with allyes config.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

"In some cases, especially on modern laptops with a lot of PCI and cardbus
bridges, we're unable to assign correct secondary/subordinate bus numbers
to all cardbus bridges due to BIOS limitations unless we are using
"pci=assign-busses" boot option." -- Ivan Kokshaysky (from a patch comment)

Without it, Cardbus cards inserted are never seen by PCI because the parent
PCI-PCI Bridge of the Cardbus bridge will not pass and translate Type 1 PCI
configuration cycles correctly and the system will fail to find and
initialise the PCI devices in the system.

Reference: PCI-PCI Bridges: PCI Configuration Cycles and PCI Bus Numbering:
http://www.science.unitn.it/~fiorella/guidelinux/tlk/node72.html

The reason for this is that:
 ``All PCI busses located behind a PCI-PCI bridge must reside between the
secondary bus number and the subordinate bus number (inclusive).''

"pci=assign-busses" makes pcibios_assign_all_busses return 1 and this
turns on PCI renumbering during PCI probing.

Alan suggested to use DMI automatically set assign-busses on problem systems.

The only question for me was where to put it.  I put it directly before
scanning PCI bus into pcibios_scan_root() because it's called from legacy,
acpi and numa and so it can be one place for all systems and configurations
which may need it.

AMD64 Laptops are also affected and fixed by assign-busses, and the code is
also incuded from arch/x86_64/pci/ that place will also work for x86_64
kernels, I only ifdef'-ed the x86-only Laptop in this example.

Affected and known or assumed to be fixed with it are (found by googling):

* ASUS Z71V and L3s
* Samsung X20
* Compaq R3140us and all Compaq R3000 series laptops with TI1620 Controller,
  also Compaq R4000 series (from a kernel.org bugreport)
* HP zv5000z (AMD64 3700+, known that fixup_parent_subordinate_busnr fixes it)
* HP zv5200z
* IBM ThinkPad 240
* An IBM ThinkPad (1.8 GHz Pentium M) debugged by Pavel Machek
  gives the correspondig message which detects the possible problem.
* MSI S260 / Medion SIM 2100 MD 95600

The patch also expands the "try pci=assign-busses" warning so testers will
help us to update the DMI table.

Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>