PCI: SR-IOV quirk for Intel 82576 NIC

If BIOS doesn't allocate resources for the SR-IOV BARs, zero the Flash
BAR and program the SR-IOV BARs to use the old Flash Memory Space.

Please refer to Intel 82576 Gigabit Ethernet Controller Datasheet
section 7.9.2.14.2 for details.
http://download.intel.com/design/network/datashts/82576_Datasheet.pdf

Signed-off-by: Yu Zhao <yu.zhao@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI: Setup disabled bridges even if buses are added

This patch sets up disabled bridges even if buses have already been
added.

pci_assign_unassigned_resources is called after buses are added.
pci_assign_unassigned_resources calls pci_bus_assign_resources.
pci_bus_assign_resources calls pci_setup_bridge to configure BARs of
bridges.

Currently pci_setup_bridge returns immediately if the bus have already
been added. So pci_assign_unassigned_resources can't configure BARs of
bridges that were added in a disabled state; this patch fixes the issue.

On logical hot-add, we need to prevent the kernel from re-initializing
bridges that have already been initialized. To achieve this,
pci_setup_bridge returns immediately if the bridge have already been
enabled.

We don't need to check whether the specified bus is a root bus or not.
pci_setup_bridge is not called on a root bus, because a root bus does
not have a bridge.

The patch adds a new helper function, pci_is_enabled. I made the
function name similar to pci_is_managed. The codes which use
enable_cnt directly are changed to use pci_is_enabled.

Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Yuji Shimada <shimada-yxb@necst.nec.co.jp>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI-IOV: fix missing kernel-doc

Fix PCI iov kernel-doc warning:

Warning(drivers/pci/iov.c:638): No description found for parameter 'nr_virtfn'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI: annotate pci_rescan_bus as __ref, not __devinit

pci_rescan_bus was annotated as __devinit, which is wrong,
because it will never be part of device initialization.
Howevever, we can't simply drop the annotation, because then we
get section warnings about calling pci_scan_child_bus (which is
correctly marked as __devinit).

pci_rescan_bus will only get built when CONFIG_HOTPLUG is set,
meaning that __devinit is a nop, so we know that pci_scan_child_bus
has not been freed.

Annotate as __ref to silence modpost.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI: don't corrupt enable_cnt when doing manual resource alignment

This patch fixes breakage of of enable_cnt in quirk_resource_alignment.

Currently, quirk_resource_alignment calls pci_disable_device.
pci_disable_device decrements enable_cnt, so that enable_cnt becomes -1.

The patch disables memory decoding, writing command register directly.
So enable_cnt is not broken.

Signed-off-by: Yuji Shimada <shimada-yxb@necst.nec.co.jp>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI: Fix oops in pci_vpd_truncate

pci_vpd_truncate() should check for dev->vpd->attr, otherwise
this might happen:

sky2 driver version 1.22
Unable to handle kernel paging request for data at address 0x0000000c
Faulting instruction address: 0xc01836fc
Oops: Kernel access of bad area, sig: 11 [#1]
[...]
NIP [c01836fc] pci_vpd_truncate+0x38/0x40
LR [c029be18] sky2_probe+0x14c/0x518
Call Trace:
[ef82bde0] [c029bda4] sky2_probe+0xd8/0x518 (unreliable)
[ef82be20] [c018a11c] local_pci_probe+0x24/0x34
[ef82be30] [c018a14c] pci_call_probe+0x20/0x30
[ef82be50] [c018a330] __pci_device_probe+0x64/0x78
[ef82be60] [c018a44c] pci_device_probe+0x30/0x58
[ef82be80] [c01aa270] really_probe+0x78/0x1a0
[ef82bea0] [c01aa460] __driver_attach+0xa4/0xa8
[ef82bec0] [c01a96ac] bus_for_each_dev+0x60/0x9c
[ef82bef0] [c01aa0b4] driver_attach+0x24/0x34
[ef82bf00] [c01a9e08] bus_add_driver+0x12c/0x1cc
[ef82bf20] [c01aa87c] driver_register+0x6c/0x110
[ef82bf30] [c018a770] __pci_register_driver+0x4c/0x9c
[ef82bf50] [c03782c8] sky2_init_module+0x30/0x40
[ef82bf60] [c0001dbc] do_one_initcall+0x34/0x1a0
[ef82bfd0] [c0362240] do_initcalls+0x38/0x58

This happens with CONFIG_SKY2=y, and "ip=on" kernel command line, so
pci_vpd_truncate() is called before late_initcall(pci_sysfs_init),
therefore ->attr isn't yet initialized.

Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI: allow PCI core hotplug to remove PCI root bus

There is no reason to prevent removal of root bus devices. A subsequent
rescan will find them just fine.

Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI Hotplug: acpiphp: grab refcount on p2p subordinate bus

If a logical hot unplug (remove) is performed on a bridge claimed
by acpiphp and then acpiphp is unloaded, we will encounter an oops.

This is because acpiphp will access the bridge's subordinate bus,
which was released by the user's prior hot unplug.

The solution is to grab a reference on the subordinate PCI bus.
This will prevent the bus from release until acpiphp is unloaded.

Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reported-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
PCI: pci_slot: grab refcount on slot's bus

If a logical hot unplug (remove) is performed on a physical PCI slot's
parent bridge, and then pci_slot is unloaded, we will encounter an oops:

  [<ffffffff803a788a>] kobject_release+0x9a/0x290
  [<ffffffff803a77f0>] ? kobject_release+0x0/0x290
  [<ffffffff803a8ce7>] kref_put+0x37/0x80
  [<ffffffff803a76f7>] kobject_put+0x27/0x60
  [<ffffffff803bebcc>] ? pci_destroy_slot+0x3c/0xc0
  [<ffffffff803bebd5>] pci_destroy_slot+0x45/0xc0
  [<ffffffffa000f05c>] acpi_pci_slot_remove+0x5c/0x91 [pci_slot]
  [<ffffffff8040064b>] acpi_pci_unregister_driver+0x4b/0x62
  [<ffffffffa000f5c8>] acpi_pci_slot_exit+0x10/0x12 [pci_slot]
  [<ffffffff80276ce1>] sys_delete_module+0x161/0x250

We need to grab a reference to the parent PCI bus, which will pin
the bus and prevent it from being released until pci_slot is unloaded.

Cc: lenb@kernel.org
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Tested-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Reported-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: pci_slot: grab refcount on slot's bus
  PCI Hotplug: acpiphp: grab refcount on p2p subordinate bus
  PCI: allow PCI core hotplug to remove PCI root bus
  PCI: Fix oops in pci_vpd_truncate
  PCI: don't corrupt enable_cnt when doing manual resource alignment
  PCI: annotate pci_rescan_bus as __ref, not __devinit
  PCI-IOV: fix missing kernel-doc
  PCI: Setup disabled bridges even if buses are added
  PCI: SR-IOV quirk for Intel 82576 NIC
NFS: Fix the return value in nfs_page_mkwrite()

Commit c2ec175c39f62949438354f603f4aa170846aabb ("mm: page_mkwrite
change prototype to match fault") exposed a bug in the NFS
implementation of page_mkwrite.  We should be returning 0 on success...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge commit '2b2ec75' into wip-unstable
migrate defconfig to PREEMPT_RCU