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: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

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: NYuji Shimada <shimada-yxb@necst.nec.co.jp>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

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: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Fix PCI iov kernel-doc warning:

Warning(drivers/pci/iov.c:638): No description found for parameter 'nr_virtfn'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

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: NAlex Chiang <achiang@hp.com>
Signed-off-by: NYuji Shimada <shimada-yxb@necst.nec.co.jp>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

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.pdfSigned-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

If the device is not supposed to wake up the system, ie. when
device_may_wakeup(&dev->dev) returns 'false', pci_prepare_to_sleep()
should pass 'false' to pci_enable_wake() so that it calls the
platform to disable the wake-up capability of the device.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

The radeonfb driver needs to program the device's PMCSR directly due
to some quirky hardware it has to handle (see
http://bugzilla.kernel.org/show_bug.cgi?id=12846 for details) and
after doing that it needs to call the platform (usually ACPI) to
finish the power transition of the device.  Currently it uses
pci_set_power_state() for this purpose, however making a specific
assumption about the internal behavior of this function, which has
changed recently so that this assumption is no longer satisfied.
For this reason, introduce __pci_complete_power_transition() that may
be called by the radeonfb driver to complete the power transition of
the device.  For symmetry, introduce __pci_start_power_transition().
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

At present the configuration spaces of PCI devices that have no
drivers or no PM support in the drivers (either legacy or through a
pm object) are not saved during suspend and, consequently, they are
not restored during resume.  This generally may lead to the state of
the system being slightly inconsistent after the resume, so it's
better to save and restore the configuration spaces of these devices
as well.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

There is a problem with PCI devices without any PM support (either
native or through the platform) that pci_set_power_state() always
returns error code for them, even if they are being put into D0.
However, such devices are always in D0, so pci_set_power_state()
should return success when attempting to put such a device into D0.
It also should update the current_state field for these devices as
appropriate.  This modification is necessary so that the standard
configuration registers of these devices are successfully restored by
pci_restore_standard_config() during the "early" phase of resume.

In addition, pci_set_power_state() should check the value of
current_state before calling the platform to change the power state
of the device to avoid doing that unnecessarily.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Once we have allowed timer interrupts to be enabled during the late
phase of suspending devices, we are now able to use the generic
pci_set_power_state() to put PCI devices into low power states at
that time.  We can also use some related platform callbacks, like the
ones preparing devices for wake-up, during the late suspend.

Doing this will allow us to avoid the race condition where a device
using shared interrupts is put into a low power state with interrupts
enabled and then an interrupt (for another device) comes in and
confuses its driver.  At the same time, devices that don't support
the native PCI PM or that require some additional, platform-specific
operations to be carried out to put them into low power states will
be handled as appropriate.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Move pci_restore_standard_config() from pci.c to pci-driver.c and
make it static.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Once we have allowed timer interrupts to be enabled during the early
phase of resuming devices, we are now able to use the generic
pci_set_power_state() to put PCI devices into D0 at that time.  Then,
the platform-specific PM code will have a chance to handle devices
that don't implement the native PCI PM or that require some
additional, platform-specific operations to be carried out to power
them up.  Also, by doing this we can simplify the code quite a bit.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>

I noticed two functions use a variable "i" to store the return value of PM
function calls while the rest of the file uses "error". As "i" normally
indicates a counter of some sort it seems better to keep this consistent.
Signed-off-by: NFrans Pop <elendil@planet.nl>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

Impact: fix bug

This patch reworks the nv_msi_ht_cap_quirk() and will only try to avoid
to enable ht_msi on device following that root dev, and don't touch that
root dev, but only do that trick with end_device on the chain.
Reported-by: NPrakash Punnoor <prakash@punnoor.de>
Tested-by: NPrakash Punnoor <prakash@punnoor.de>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Fix misspelling of firmware.
Signed-off-by: NNick Andrew <nick@nick-andrew.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Impact: fix bug

Prakash reported that his c51-mcp51 system ondie sound card doesn't work
MSI but if he hack out the HT-MSI on mcp51, the MSI will work well with
sound card.

This patch reworks nv_msi_ht_cap_quirk() and will only avoid enabling
ht_msi on devices following that root device.
Reported-by: NPrakash Punnoor <prakash@punnoor.de>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

PCIe 2.0 defines several new registers (Device Control 2, Link Control 2,
and Slot Control 2). Save and retore them in pci_save_pcie_state() and
pci_restore_pcie_state().
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Get rid of a new use of bus_id that snuck in.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Fix the following kernel oops problem that happens when removing PCI
bridge with pciehp loaded. It should also occur with other hotplug
driver that is implemented as a bridge's driver.

[  459.997257] pciehp 0000:2f:04.0:pcie24: unloading service driver pciehp
[  459.997495] general protection fault: 0000 [#1] SMP
[  459.997737] last sysfs file: /sys/devices/pci0000:00/0000:00:04.0/0000:2e:00.0/0000:2f:04.0/remove
[  459.997964] CPU 4
[  459.998129] Modules linked in: pciehp ipv6 autofs4 hidp rfcomm l2cap bluetooth sunrpc cpufreq_ondemand acpi_cpufreq dm_mirror dm_region_hash dm_log dm_multipath scsi_dh dm_mod sbs sbshc battery ac parport_pc lp parport mptspi mptscsih mptbase scsi_transport_spi e1000e sg sr_mod cdrom button serio_raw i2c_i801 i2c_core shpchp pcspkr ata_piix libata megaraid_sas sd_mod scsi_mod crc_t10dif ext3 jbd uhci_hcd ohci_hcd ehci_hcd [last unloaded: microcode]
[  459.998129] Pid: 56, comm: events/4 Not tainted 2.6.29-rc8-kk #1 PRIMERGY
[  459.998129] RIP: 0010:[<ffffffff803bf047>]  [<ffffffff803bf047>] pci_slot_release+0x37/0x100
[  459.998129] RSP: 0018:ffff88083b3bf9e0  EFLAGS: 00010246
[  459.998129] RAX: ffff88083adc5158 RBX: ffff880836c1bc80 RCX: 6b6b6b6b6b6b6b6b
[  459.998129] RDX: 0000000000000000 RSI: ffffffff803a77f0 RDI: ffff880836c1bc48
[  459.998129] RBP: ffff88083b3bfa00 R08: 0000000000000002 R09: 0000000000000000
[  459.998129] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880836c1bc48
[  459.998129] R13: ffff880836c1bc20 R14: ffff880836c1bc48 R15: ffff880836d1ec38
[  459.998129] FS:  0000000000000000(0000) GS:ffff88083ccc3770(0000) knlGS:0000000000000000
[  459.998129] CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[  459.998129] CR2: 00007f1562f1d558 CR3: 0000000838090000 CR4: 00000000000006e0
[  459.998129] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  459.998129] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  459.998129] Process events/4 (pid: 56, threadinfo ffff88083b3be000, task ffff88083b3b3e40)
[  459.998129] Stack:
[  459.998129]  ffff880836c1bc80 ffff880836c1bc48 ffffffff80793320 ffff88083b0d0960
[  459.998129]  ffff88083b3bfa30 ffffffff803a788a ffff880836c1bc80 ffffffff803a77f0
[  459.998129]  ffff880836c1bc20 ffff880836d1ec38 ffff88083b3bfa50 ffffffff803a8ce7
[  459.998129] Call Trace:
[  459.998129]  [<ffffffff803a788a>] kobject_release+0x9a/0x290
[  459.998129]  [<ffffffff803a77f0>] ? kobject_release+0x0/0x290
[  459.998129]  [<ffffffff803a8ce7>] kref_put+0x37/0x80
[  459.998129]  [<ffffffff803a76f7>] kobject_put+0x27/0x60
[  459.998129]  [<ffffffff803bebcc>] ? pci_destroy_slot+0x3c/0xc0
[  459.998129]  [<ffffffff803bebd5>] pci_destroy_slot+0x45/0xc0
[  459.998129]  [<ffffffff803c797d>] pci_hp_deregister+0x13d/0x210
[  459.998129]  [<ffffffffa031141d>] cleanup_slots+0x2d/0x80 [pciehp]
[  459.998129]  [<ffffffffa0311735>] pciehp_remove+0x15/0x30 [pciehp]
[  459.998129]  [<ffffffff803c4c99>] pcie_port_remove_service+0x69/0x90
[  459.998129]  [<ffffffff80441da9>] __device_release_driver+0x59/0x90
[  459.998129]  [<ffffffff80441edb>] device_release_driver+0x2b/0x40
[  459.998129]  [<ffffffff804419d6>] bus_remove_device+0xa6/0x120
[  459.998129]  [<ffffffff8043e46b>] device_del+0x12b/0x190
[  459.998129]  [<ffffffff803c4d90>] ? remove_iter+0x0/0x40
[  459.998129]  [<ffffffff8043e4f6>] device_unregister+0x26/0x70
[  459.998129]  [<ffffffff803c4dbf>] remove_iter+0x2f/0x40
[  459.998129]  [<ffffffff8043ddf3>] device_for_each_child+0x33/0x60
[  459.998129]  [<ffffffff8033ee30>] ? sysfs_schedule_callback_work+0x0/0x50
[  459.998129]  [<ffffffff803c4d30>] pcie_port_device_remove+0x30/0x80
[  459.998129]  [<ffffffff803c55a1>] pcie_portdrv_remove+0x11/0x20
[  459.998129]  [<ffffffff803bfeb2>] pci_device_remove+0x32/0x70
[  459.998129]  [<ffffffff80441da9>] __device_release_driver+0x59/0x90
[  459.998129]  [<ffffffff80441edb>] device_release_driver+0x2b/0x40
[  459.998129]  [<ffffffff804419d6>] bus_remove_device+0xa6/0x120
[  459.998129]  [<ffffffff8043e46b>] device_del+0x12b/0x190
[  459.998129]  [<ffffffff8043e4f6>] device_unregister+0x26/0x70
[  459.998129]  [<ffffffff803ba969>] pci_stop_dev+0x49/0x60
[  459.998129]  [<ffffffff803baab0>] pci_remove_bus_device+0x40/0xc0
[  459.998129]  [<ffffffff803c10d9>] remove_callback+0x29/0x40
[  459.998129]  [<ffffffff8033ee4f>] sysfs_schedule_callback_work+0x1f/0x50
[  459.998129]  [<ffffffff8025769a>] run_workqueue+0x15a/0x230
[  459.998129]  [<ffffffff80257648>] ? run_workqueue+0x108/0x230
[  459.998129]  [<ffffffff8025846f>] worker_thread+0x9f/0x100
[  459.998129]  [<ffffffff8025bce0>] ? autoremove_wake_function+0x0/0x40
[  459.998129]  [<ffffffff802583d0>] ? worker_thread+0x0/0x100
[  459.998129]  [<ffffffff8025b89d>] kthread+0x4d/0x80
[  459.998129]  [<ffffffff8020d4ba>] child_rip+0xa/0x20
[  459.998129]  [<ffffffff8020cebc>] ? restore_args+0x0/0x30
[  459.998129]  [<ffffffff8025b850>] ? kthread+0x0/0x80
[  459.998129]  [<ffffffff8020d4b0>] ? child_rip+0x0/0x20
[  459.998129] Code: 56 49 89 fe 41 55 4c 8d 6f d8 41 54 53 74 09 f6 05 b8 05 c7 00 08 75 72 49 8b 45 00 48 8b 48 28 eb 05 66 90 48 89 f1 49 8b 45 00 <48> 8b 31 48 83 c0 28 0f 18 0e 48 39 c1 74 1c 8b 41 38 41 0f b6
[  459.998129] RIP  [<ffffffff803bf047>] pci_slot_release+0x37/0x100
[  459.998129]  RSP <ffff88083b3bf9e0>
[  460.018595] ---[ end trace 5a08d2095374aedc ]---

The pci_remove_bus_device() removes all buses and devices under the
bridge, and then removes the bridge. So the remove() callback of the
hotplug drivers implemented as a bridge's driver is executed after the
struct pci_bus of the bridge's secondary bus is removed. The remove()
callback of those driver unregisters the slot using pci_destroy_slot(),
and slot's release callback refers to the the struct pci_bus that was
already freed. This is the cause of the kernel oops.

This patch solves the problem by stopping bus drivers before removing the
bridge and its child bus and devices.
Acked-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

New pci_cfg_space_size() needs invalid pdev->class, put it in the
right place in the pci_setup_device().
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Add new flags in the Boot Architecture flags field. Update comments
for all FADT flags. Add FADT version when each flag was defined.
Signed-off-by: NBob Moore <robert.moore@intel.com>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The problem is in dma_pte_clear_range and dma_pte_free_pagetable. When
intel_unmap_single and intel_unmap_sg call them, the end address may be
zero if the 'start_addr + size' rounds up. So no PTE gets cleared. The
uncleared PTE fires the BUG_ON when it's used again to create new mappings.

After I modified dma_pte_clear_range a bit, the BUG_ON is gone.

Tested both 32 and 32 PAE modes on Intel X58 and Q35 platforms.
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

If we fix a few highmem-related thinkos and a couple of printk format
warnings, the Intel IOMMU driver works fine in a 32-bit kernel.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

When assign a device behind conventional PCI bridge or PCIe to
PCI/PCI-x bridge to a domain, it must assign its bridge and may
also need to assign secondary interface to the same domain.

Dependent assignment is already there, but dependent
deassignment is missed when detach device from virtual machine.
This results in conventional PCI device assignment failure after
it has been assigned once. This patch addes dependent
deassignment, and fixes the issue.
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Cc: jbarnes@virtuousgeek.org
Cc: linux-pci@vger.kernel.org
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>

The user can request to enable snooping control through VT-d page table.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

This iommu_op can tell if domain have a specific capability, like snooping
control for Intel IOMMU, which can be used by other components of kernel to
adjust the behaviour.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

Snooping control enabled IOMMU to guarantee DMA cache coherency and thus reduce
software effort (VMM) in maintaining effective memory type.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

We wanted to replace fakephp wholesale, so rename legacy_fakephp back
to fakephp. Yes, this is a silly commit, but it produces a much easier
patch to read and review.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

A complete re-implementation of fakephp is necessary if it is to
present its former interface (pre-2.6.27, when it broke). The
reason is that PCI hotplug drivers call pci_hp_register(), which
enforces the rule that only one /sys/bus/pci/slots/ file may be
created per physical slot.

The change breaks the old fakephp's assumption that it could
create a file per function. So we re-implement fakephp to avoid
using the standard PCI hotplug API so that we can restore the old
fakephp user interface.

It puts entries in /sys/bus/pci/slots with the names of all PCI
devices/functions, exactly symmetrical to what is shown in
/sys/bus/pci/devices. Each slots/ entry has a "power" attribute,
which works the same way as the fakephp driver's power attribute
has worked.

There are a few improvements over old fakephp, which couldn't handle
PCI devices being added or removed via a means outside of
fakephp's knowledge.  If a device was added another way, old fakephp
didn't notice and didn't create the fake slot for it.  If a
device was removed another way, old fakephp didn't delete the fake
slot for it (and accessing the stale slot caused an oops).

The new implementation overcomes these limitations. As a
consequence, removing a bridge with other devices behind it now
works as well, which is something else old fakephp couldn't do
previously.

This duplicates a tiny bit of the code in the PCI core that does
this same function.  Re-using that code ends up being more
complex than duplicating it, and it makes code in the PCI core
more ugly just to support this legacy fakephp interface
compatibility layer.
Reviewed-by: NJames Cameron <qz@hp.com>
Signed-off-by: NTrent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This interface allows the user to force a rescan of the device's
parent bus and all subordinate buses, and rediscover devices removed
earlier from this part of the device tree.

Cc: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This patch adds an attribute named "remove" to a PCI device's sysfs
directory.  Writing a non-zero value to this attribute will remove the PCI
device and any children of it.

Trent Piepho wrote the original implementation and documentation.

Thanks to Vegard Nossum for testing under kmemcheck and finding locking
issues with the sysfs interface.

Cc: Trent Piepho <xyzzy@speakeasy.org>
Tested-by: NVegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This interface allows the user to force a rescan of all PCI buses
in system, and rediscover devices that have been removed earlier.

pci_bus_attrs implementation from Trent Piepho.

Thanks to Vegard Nossum for discovering locking issues with the
sysfs interface.

Cc: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

This API is used by the PCI core to rescan a bus and rediscover
newly added devices.

Over time, it is expected that the various PCI hotplug drivers
will migrate to this interface and away from the old
pci_do_scan_bus() interface.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

In preparation for PCI core hotplug, we need to ensure that we do
not attempt to re-enable bridges that have already been enabled.
Reported-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

In preparation for PCI core hotplug, we need to ensure that we do
not attempt to re-initialize bridges that have already been initialized.

We only need to worry about non-root buses, since we will not allow
root bus removal.
Reported-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

While scanning bridges, we stop our scan if we encounter a bus
that we've seen before, to work around some buggy chipsets. This
is a good idea, but prevents us from fully scanning the PCI bus
at a future time (to find newly hot-added devices, for example).

Change the logic so that we skip _re-adding_ an existing bus
that we've seen before, but also allow the scan to descend to
all child buses.

Now that we're potentially scanning our child buses again, we
also need to be sure not to attempt re-initializing their BARs
so we avoid that.

This patch lays the groundwork to allow the user to issue a
rescan of the PCI bus at any time.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pci_scan_slot() has been rewritten to be less complex and will now
return the number of *new* devices found.

Existing callers need not worry because they already assume that
they can't call pci_scan_slot() on an already-scanned slot.

Thus, there is no semantic change for existing callers: returning
newly found devices (this patch) is exactly equal to returning all
found devices (before this patch).

This patch adds some more groundwork to allow us to rescan the
PCI bus during runtime to discover newly added devices.
Signed-off-by: NTrent Piepho <xyzzy@speakeasy.org>
Reviewed-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

pci_scan_single_device is supposed to add newly discovered
devices to pci_bus->devices, but doesn't check to see if the
device has already been added. This can cause problems if we ever
want to use this interface to rescan the PCI bus.

If the device is already added, just return it.
Signed-off-by: NTrent Piepho <xyzzy@speakeasy.org>
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>