Commit Graph

134557 Commits

Author SHA1 Message Date
Bjorn Helgaas 39c2462e16 parisc/PCI: get rid of device resource fixups
Tell the PCI core about host bridge address translation so it can take
care of bus-to-resource conversion for us.

CC: linux-parisc@vger.kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:19:03 -07:00
Bjorn Helgaas 36a66cd6fd PCI: add generic pcibios_resource_to_bus()
This replaces the generic versions of pcibios_resource_to_bus() and
pcibios_bus_to_resource() in asm-generic/pci.h with versions that use
pci_resource_to_bus() and pci_bus_to_resource().

The replacements are equivalent except that they can apply host
bridge window offsets when the arch has supplied them by using
pci_add_resource_offset().

Each arch can convert to using pci_add_resource_offset() individually by
removing its device resource fixups from pcibios_fixup_bus() and supplying
ARCH_HAS_GENERIC_PCI_OFFSETS.  ARCH_HAS_GENERIC_PCI_OFFSETS can be removed
after all have converted.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:19:00 -07:00
Bjorn Helgaas 5bfa14ed9f PCI: convert bus addresses to resource when reading BARs
Some PCI host bridges translate CPU addresses to PCI bus addresses.
Previously, we initialized pci_dev resources with PCI bus addresses,
then converted them to CPU addresses later in arch-specific code
(pcibios_fixup_resources()), which leaves a window of time where the
pci_dev resources are incorrect.

This patch adds support in the core for this address translation.
When the arch creates the root bus, it can supply the host bridge
address translation information, and the core can use it to set the
pci_dev resources correctly from the beginning.

This gives us a way to fix the problem that quirks that run between device
discovery and pcibios_fixup_resources() fail because they use pci_dev
resources that haven't been converted.  The reference below is to one
such problem that affected ARM and ia64.

Note that this patch has no effect until an arch starts using
pci_add_resource_offset() with a non-zero offset: before that, all
all host bridge windows have a zero offset and pci_bus_to_resource()
copies the pci_bus_region directly to the struct resource.

Reference: https://lkml.org/lkml/2009/10/12/405
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:19:00 -07:00
Bjorn Helgaas 0efd5aab41 PCI: add struct pci_host_bridge_window with CPU/bus address offset
Some PCI host bridges apply an address offset, so bus addresses on PCI are
different from CPU addresses.  This patch adds a way for architectures to
tell the PCI core about this offset.  For example:

    LIST_HEAD(resources);
    pci_add_resource_offset(&resources, host->io_space, host->io_offset);
    pci_add_resource_offset(&resources, host->mem_space, host->mem_offset);
    pci_scan_root_bus(parent, bus, ops, sysdata, &resources);

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:19:00 -07:00
Bjorn Helgaas 5a21d70dbd PCI: add struct pci_host_bridge and a list of all bridges found
This adds a list of all PCI host bridges we find and a way to look up
the host bridge from a pci_dev.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:18:59 -07:00
Bjorn Helgaas a5390aa6dc PCI: don't publish new root bus until it's fully initialized
When pci_create_root_bus() adds the new struct pci_bus to the global
pci_root_buses list, the bus becomes visible to other parts of the
kernel, so it should be fully initialized.

This patch delays adding the bus to the pci_root_buses list until after
all the struct pci_bus initialization is finished.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:18:59 -07:00
Bjorn Helgaas 844393f4c5 PCI: make pci_flags non-weak
No architecture defines its own pci_flags, so the core symbol does not
need to be weak.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:18:59 -07:00
Bjorn Helgaas 47087700ce PCI: make pci_flags always available
If we move resource assignment functions into the core, we'll still
need a way for architectures to prevent reassignment, e.g., the
"pci_probe_only" functionality, and we'll need a generic, always
available way the core can test for that.  The "pci_flags"
arrangement used by several architectures seems like a convenient
way to do this.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2012-02-23 20:18:55 -07:00
MUNEDA Takahiro 7570a333d8 PCI: Add pcie_hp=nomsi to disable MSI/MSI-X for pciehp driver
Add a parameter to avoid using MSI/MSI-X for PCIe native hotplug; it's
known to be buggy on some platforms.

In my environment, while shutting down, following stack trace is shown
sometimes.

  irq 16: nobody cared (try booting with the "irqpoll" option)
  Pid: 1081, comm: reboot Not tainted 3.2.0 #1
  Call Trace:
   <IRQ>  [<ffffffff810cec1d>] __report_bad_irq+0x3d/0xe0
   [<ffffffff810cee1c>] note_interrupt+0x15c/0x210
   [<ffffffff810cc485>] handle_irq_event_percpu+0xb5/0x210
   [<ffffffff810cc621>] handle_irq_event+0x41/0x70
   [<ffffffff810cf675>] handle_fasteoi_irq+0x55/0xc0
   [<ffffffff81015356>] handle_irq+0x46/0xb0
   [<ffffffff814fbe9d>] do_IRQ+0x5d/0xe0
   [<ffffffff814f146e>] common_interrupt+0x6e/0x6e
   [<ffffffff8106b040>] ? __do_softirq+0x60/0x210
   [<ffffffff8108aeb1>] ? hrtimer_interrupt+0x151/0x240
   [<ffffffff814fb5ec>] call_softirq+0x1c/0x30
   [<ffffffff810152d5>] do_softirq+0x65/0xa0
   [<ffffffff8106ae9d>] irq_exit+0xbd/0xe0
   [<ffffffff814fbf8e>] smp_apic_timer_interrupt+0x6e/0x99
   [<ffffffff814f9e5e>] apic_timer_interrupt+0x6e/0x80
   <EOI>  [<ffffffff814f0fb1>] ? _raw_spin_unlock_irqrestore+0x11/0x20
   [<ffffffff812629fc>] pci_bus_write_config_word+0x6c/0x80
   [<ffffffff81266fc2>] pci_intx+0x52/0xa0
   [<ffffffff8127de3d>] pci_intx_for_msi+0x1d/0x30
  [<ffffffff8127e4fb>] pci_msi_shutdown+0x7b/0x110
   [<ffffffff81269d34>] pci_device_shutdown+0x34/0x50
   [<ffffffff81326c4f>] device_shutdown+0x2f/0x140
   [<ffffffff8107b981>] kernel_restart_prepare+0x31/0x40
   [<ffffffff8107b9e6>] kernel_restart+0x16/0x60
   [<ffffffff8107bbfd>] sys_reboot+0x1ad/0x220
   [<ffffffff814f4b90>] ? do_page_fault+0x1e0/0x460
   [<ffffffff811942d0>] ? __sync_filesystem+0x90/0x90
   [<ffffffff8105c9aa>] ? __cond_resched+0x2a/0x40
   [<ffffffff814ef090>] ? _cond_resched+0x30/0x40
   [<ffffffff81169e17>] ? iterate_supers+0xb7/0xd0
   [<ffffffff814f9382>] system_call_fastpath+0x16/0x1b
  handlers:
  [<ffffffff8138a0f0>] usb_hcd_irq
  [<ffffffff8138a0f0>] usb_hcd_irq
  [<ffffffff8138a0f0>] usb_hcd_irq
  Disabling IRQ #16

An un-wanted interrupt is generated when PCI driver switches from
MSI/MSI-X to INTx while shutting down the device.  The interrupt does
not happen if MSI/MSI-X is not used on the device.
I confirmed that this problem does not happen if pcie_hp=nomsi was
specified and hotplug operation worked fine as usual.

v2: Automatically disable MSI/MSI-X against following device:
    PCI bridge: Integrated Device Technology, Inc. Device 807f (rev 02)
v3: Based on the review comment, combile the if statements.
v4: Removed module parameter.
    Move some code to build pciehp as a module.
    Move device specific code to driver/pci/quirks.c.
v5: Drop a device specific code until getting a vendor statement.

Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: MUNEDA Takahiro <muneda.takahiro@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:29:35 -08:00
Yinghai Lu 34a4876e30 PCI: move pci_find_saved_cap out of linux/pci.h
Only one user in driver/pci/pci.c, so we don't need to put it in global
pci.h

Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:27:11 -08:00
Yinghai Lu f796841e49 PCI: fix memleak for pci dev removing during hotplug
unreferenced object 0xffff880276d17700 (size 64):
  comm "swapper/0", pid 1, jiffies 4294897182 (age 3976.028s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 18 f9 de 76 02 88 ff ff  ...........v....
    10 00 00 00 0e 00 00 00 0f 28 40 00 00 00 00 00  .........(@.....
  backtrace:
    [<ffffffff81c8aede>] kmemleak_alloc+0x26/0x43
    [<ffffffff811385f0>] __kmalloc+0x121/0x183
    [<ffffffff813cf821>] pci_add_cap_save_buffer+0x35/0x7c
    [<ffffffff813d12b7>] pci_allocate_cap_save_buffers+0x1d/0x65
    [<ffffffff813cdb52>] pci_device_add+0x92/0xf1
    [<ffffffff81c8afe6>] pci_scan_single_device+0x9f/0xa1
    [<ffffffff813cdbd2>] pci_scan_slot.part.20+0x21/0x106
    [<ffffffff813cdce2>] pci_scan_slot+0x2b/0x35
    [<ffffffff81c8dae4>] __pci_scan_child_bus+0x51/0x107
    [<ffffffff81c8d75b>] pci_scan_bridge+0x376/0x6ae
    [<ffffffff81c8db60>] __pci_scan_child_bus+0xcd/0x107
    [<ffffffff81c8dbab>] pci_scan_child_bus+0x11/0x2a
    [<ffffffff81cca58c>] pci_acpi_scan_root+0x18b/0x21c
    [<ffffffff81c916be>] acpi_pci_root_add+0x1e1/0x42a
    [<ffffffff81406210>] acpi_device_probe+0x50/0x190
    [<ffffffff814a0227>] really_probe+0x99/0x126

Need to free saved_buffer for capabilities.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:08:53 -08:00
Yinghai Lu 2dd8ba921d PCI: Fix device class print out
Found debug print of class is shifted.

| pci 0000:f8:15.2: [8086:2b56] type 0 class 0x000600

Code is trying to print class with 6 digits, but use shifted class with
4 digits valid value as variable.

Change to original dev->class directly.

Also remove not needed calculating of local variable class, because it
will be updated after pci_fixup_device(pci_fixup_early...)

Also unify type print out when class and header is not matched.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:05:59 -08:00
Yinghai Lu 3796f1e2ca PCI: Skip cardbus assigned resource reset during pci bus rescan
Otherwise when rescan is used for cardbus, assigned resources will get
cleared.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 12:00:04 -08:00
Yinghai Lu 1184893439 PCI: Fix "cardbus bridge resources as optional" size handling
We should not set the requested size to -2; that will confuse the
resource list sorting with align when SIZEALIGN is used.

Change to STARTALIGN and pass align from start;  we are safe to do that
just as we do that regular pci bridge.  In the long run, we should just
treat cardbus like a regular pci bridge.

Also fix the case when realloc_head is not passed: we should keep the
requested size.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 11:59:56 -08:00
Yinghai Lu dcef0d06b3 PCI: Disable cardbus bridge MEM1 prefetchable bit
Some BIOSes enable prefetch on both MEM0 and MEM1.  But the cardbus code
assumes MEM1 is non-pref...

Discussion could be found at:
	https://lkml.org/lkml/2012/1/12/1
	https://bugzilla.kernel.org/show_bug.cgi?id=41622#c23

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Tested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-23 11:59:45 -08:00
Rafael J. Wysocki 5b415f1e79 PCI / PM: Disable wakeup during shutdown for devices not enabled to wake up
If a PCI device is enabled to generate wakeup signals (PME) when put
into a low-power state by runtime PM, it will be still enabled to
generate those signals after the system shutdown, unless its driver's
.shutdown() callback takes care of the wakeup signals generation
setting.  Moreover, there are devices that are not enabled to wake
up the system and that are configured by runtime PM to generate
wakeup signals so that (runtime) remote wakeup works with them.
Those devices should be reconfigured during system shutdown so that
they don't generate wakeup signals, but at least some drivers don't
do that.  However, that very well may be done by the PCI core so
that drivers don't have to worry about it.  For this reason, modify
pci_device_shutdown() to disable the generation of wakeup events for
devices not supposed to wake up the system.

References: https://bugzilla.kernel.org/show_bug.cgi?id=37952
Reported-and-tested-by: Kamil Iskra <kamil.54002@iskra.name>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-17 09:22:04 -08:00
Yinghai Lu 09cedbef44 PCI: Fix /sys warning when sriov enabled and card is hot removed
sysfs is a bit stricter now and emits warnings in more cases.

For SRIOV hotplug, we are calling pci_stop_dev() for each VF first
(after we update pci_stop_bus_devices) which remove each VF subdir.  So
double check the VF dir in /sys before trying to remove the physfn link.

Signed-of-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-17 09:22:03 -08:00
Matthew Garrett ad71c96213 PCI: pcie: Add support for setting default ASPM policy
Distributions may wish to provide different defaults for PCIE ASPM
depending on their target audience. Provide a configuration option for
choosing the default policy.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-17 09:22:03 -08:00
Thomas Jarosch f67fd55fa9 PCI: Add quirk for still enabled interrupts on Intel Sandy Bridge GPUs
Some BIOS implementations leave the Intel GPU interrupts enabled,
even though no one is handling them (f.e. i915 driver is never loaded).
Additionally the interrupt destination is not set up properly
and the interrupt ends up -somewhere-.

These spurious interrupts are "sticky" and the kernel disables
the (shared) interrupt line after 100.000+ generated interrupts.

Fix it by disabling the still enabled interrupts.
This resolves crashes often seen on monitor unplug.

Tested on the following boards:
- Intel DH61CR: Affected
- Intel DH67BL: Affected
- Intel S1200KP server board: Affected
- Asus P8H61-M LE: Affected, but system does not crash.
  Probably the IRQ ends up somewhere unnoticed.

According to reports on the net, the Intel DH61WW board is also affected.

Many thanks to Jesse Barnes from Intel for helping
with the register configuration and to Intel in general
for providing public hardware documentation.

Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Tested-by: Charlie Suffin <charlie.suffin@stratus.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:26 -08:00
Arjan van de Ven 3209874a1d PCI: Annotate PCI quirks in initcall_debug style
While diagnosing some boot time issues on a platform, all that I
could see in the bootgraph/dmesg was that the system was spending
a lot of time in applying one or more PCI quirks... which
was virtually undebuggable.

This patch adds printk's in "initcall_debug" style to the dmesg,
which are added when the user asks for the initcall_debug
(the nr one tool to use when debugging boot hangs or boot time issues)
kernel command line option.

v2: add #includes so quirks can build on non-x86

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:04 -08:00
Danny Kukawka 309c665110 PCI hotplug: cpcihp: fix debug module parameter to be bool
Fix debug variable from module parameter to be really bool to
fix 'warning: return from incompatible pointer type'.

Acked-by: Scott Murray <scott@spiteful.org>
Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:03 -08:00
Kay, Allen M 26f41062f2 PCI: check for pci bar restore completion and retry
On some OEM systems, pci_restore_state() is called while FLR has not yet
completed.  As a result, PCI BAR register restore is not successful.  This fix
reads back the restored value and compares it with saved value and re-tries 10
times before giving up.

Signed-off-by: Jean Guyader <jean.guyader@eu.citrix.com>
Signed-off-by: Eric Chanudet <eric.chanudet@citrix.com>
Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:02 -08:00
Yinghai Lu 2debd92899 PCI: pciehp: Disable/enable link during slot power off/on
On a system with a repeater on the system board to support gen2 hotplug,
we found that when an ExpressModule is removed from some slots,
/var/log/messages will be full of "card present/not present" warnings.

It turns out the root complex is continually trying to train the link to
the repeater because the repeater has not been reset.

This patch will disable the link at removal time to allow the repeater
to be reset properly.  This also prevents a potential AER message at
removal time.

Also, when testing hotplug on a system under development, we found if we
boot the system without an EM installed, and later hot-add an EM, it
does not work with Linux, but another OS is ok.  The root cause is that
BIOS left link disabled when slot was empty at boot time, and other OS
is modifying the link disable bit in link ctrl during power on/off.

So we should do the same thing to disable/enable link during power off/on.

-v2: check link DLLA bit instead of 100ms waiting.
     Separate link disable/enable functions to another patch.

Signed-off-by: Yinghai Lu <yinghai.lu@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:02 -08:00
Yinghai Lu 7f822999e1 PCI: pciehp: Add Disable/enable link functions
Will use it during power off/on of slots

Signed-off-by: Yinghai Lu <yinghai.lu@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:01 -08:00
Yinghai Lu bffe4f72fc PCI: pciehp: Add pcie_wait_link_not_active()
Will use it for link disable status checking.

Signed-off-by: Yinghai Lu <yinghai.lu@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:01 -08:00
Yinghai Lu 4e2ce405b2 PCI: pciehp: make check_link_active more helpful
A few changes:
  - remove the 'inline' and let the complier decide
  - return a bool to indicate whether the link was active
  - add a debug message to indicate link state when it beocmes active

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:00 -08:00
Yinghai Lu 2f5d8e4ff9 PCI: pciehp: replace unconditional sleep with config space access check
During reviewing
|	PCI: pciehp: wait 1000 ms before Link Training check
Linus said:
>...
> That's a *long* time, and it's irritating to the user. It makes the
> user think "the machine is slow".
>...
> And quite frankly, an unconditional one-second delay here seems bad.
>Two seconds was unacceptable, one second is just bad.

Try to access the pci conf of a pci device that is supposed to show up
in 1s.  If we can read back a valid vendor/device id, we can return
early.

Related discussion could be found:
	https://lkml.org/lkml/2011/12/6/339

-v2: seperate code to pci_bus_read_dev_vendor_id() from pci_scan_device()
    and reuse it from pciehp code. Suggested by Matthew Wilcox.
-v3: According to Kenj, don't use array in stack, and don't wait too long
    for crs, also return fail status if not found.
    Also separate pci_bus_dev_read_vendor_id() change to another patch.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:45:00 -08:00
Yinghai Lu efdc87dab1 PCI: Separate pci_bus_read_dev_vendor_id from pci_scan_device
We can reuse it for pciehp probing.

-v2: according to Kenji, fix crs timeout checking, and export the function
     for later use when pciehp is compiled as a module.

Suggested-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:59 -08:00
Yinghai Lu ac205b7bb7 PCI: make sriov work with hotplug remove
When hot removing a pci express module that has a pcie switch and supports
SRIOV, we got:

[ 5918.610127] pciehp 0000:80:02.2:pcie04: pcie_isr: intr_loc 1
[ 5918.615779] pciehp 0000:80:02.2:pcie04: Attention button interrupt received
[ 5918.622730] pciehp 0000:80:02.2:pcie04: Button pressed on Slot(3)
[ 5918.629002] pciehp 0000:80:02.2:pcie04: pciehp_get_power_status: SLOTCTRL a8 value read 1f9
[ 5918.637416] pciehp 0000:80:02.2:pcie04: PCI slot #3 - powering off due to button press.
[ 5918.647125] pciehp 0000:80:02.2:pcie04: pcie_isr: intr_loc 10
[ 5918.653039] pciehp 0000:80:02.2:pcie04: pciehp_green_led_blink: SLOTCTRL a8 write cmd 200
[ 5918.661229] pciehp 0000:80:02.2:pcie04: pciehp_set_attention_status: SLOTCTRL a8 write cmd c0
[ 5924.667627] pciehp 0000:80:02.2:pcie04: Disabling domain🚌device=0000:b0:00
[ 5924.674909] pciehp 0000:80:02.2:pcie04: pciehp_get_power_status: SLOTCTRL a8 value read 2f9
[ 5924.683262] pciehp 0000:80:02.2:pcie04: pciehp_unconfigure_device: domain🚌dev = 0000:b0:00
[ 5924.693976] libfcoe_device_notification: NETDEV_UNREGISTER eth6
[ 5924.764979] libfcoe_device_notification: NETDEV_UNREGISTER eth14
[ 5924.873539] libfcoe_device_notification: NETDEV_UNREGISTER eth15
[ 5924.995209] libfcoe_device_notification: NETDEV_UNREGISTER eth16
[ 5926.114407] sxge 0000:b2:00.0: PCI INT A disabled
[ 5926.119342] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 5926.127189] IP: [<ffffffff81353a3b>] pci_stop_bus_device+0x33/0x83
[ 5926.133377] PGD 0
[ 5926.135402] Oops: 0000 [#1] SMP
[ 5926.138659] CPU 2
[ 5926.140499] Modules linked in:
...
[ 5926.143754]
[ 5926.275823] Call Trace:
[ 5926.278267]  [<ffffffff81353a38>] pci_stop_bus_device+0x30/0x83
[ 5926.284180]  [<ffffffff81353af4>] pci_remove_bus_device+0x1a/0xba
[ 5926.290264]  [<ffffffff81366311>] pciehp_unconfigure_device+0x110/0x17b
[ 5926.296866]  [<ffffffff81365dd9>] ? pciehp_disable_slot+0x188/0x188
[ 5926.303123]  [<ffffffff81365d6f>] pciehp_disable_slot+0x11e/0x188
[ 5926.309206]  [<ffffffff81365e68>] pciehp_power_thread+0x8f/0xe0
...

 +-[0000:80]-+-00.0-[81-8f]--
 |           +-01.0-[90-9f]--
 |           +-02.0-[a0-af]--
 |           +-02.2-[b0-bf]----00.0-[b1-b3]--+-02.0-[b2]--+-00.0 Device
 |           |                               |            +-00.1 Device
 |           |                               |            +-00.2 Device
 |           |                               |            \-00.3 Device
 |           |                               \-03.0-[b3]--+-00.0 Device
 |           |                                            +-00.1 Device
 |           |                                            +-00.2 Device
 |           |                                            \-00.3 Device

root complex: 80:02.2
pci express modules: have pcie switch and are listed as b0:00.0, b1:02.0 and b1:03.0.
end devices  are b2:00.0 and b3.00.0.
VFs are: b2:00.1,... b2:00.3, and b3:00.1,...,b3:00.3

Root cause: when doing pci_stop_bus_device() with phys fn, it will stop
virt fn and remove the fn, so
	list_for_each_safe(l, n, &bus->devices)
will have problem to refer freed n that is pointed to vf entry.

Solution is just replacing list_for_each_safe() with
list_for_each_prev_safe().  This will make sure we can get valid n pointer
to PF instead of the freed VF pointer (because newly added devices are
inserted to the bus->devices list tail).

During reviewing the patch, Bjorn said:
|   The PCI hot-remove path calls pci_stop_bus_devices() via
|   pci_remove_bus_device().
|
|   pci_stop_bus_devices() traverses the bus->devices list (point A below),
|   stopping each device in turn, which calls the driver remove() method.  When
|   the device is an SR-IOV PF, the driver calls pci_disable_sriov(), which
|   also uses pci_remove_bus_device() to remove the VF devices from the
|   bus->devices list (point B).
|
|       pci_remove_bus_device
|         pci_stop_bus_device
|           pci_stop_bus_devices(subordinate)
|             list_for_each(bus->devices)             <-- A
|               pci_stop_bus_device(PF)
|                 ...
|                   driver->remove
|                     pci_disable_sriov
|                       ...
|                         pci_remove_bus_device(VF)
|                             <remove from bus_list>  <-- B
|
|   At B, we're changing the same list we're iterating through at A, so when
|   the driver remove() method returns, the pci_stop_bus_devices() iterator has
|   a pointer to a list entry that has already been freed.

Discussion thread can be found : https://lkml.org/lkml/2011/10/15/141
				 https://lkml.org/lkml/2012/1/23/360

-v5: According to Linus to make remove more robust, Change to
     list_for_each_prev_safe instead. That is more reasonable, because
     those devices are added to tail of the list before.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:59 -08:00
Yinghai Lu 67cc7e26a5 PCI: remove add_to_failed_list()
Only one user; just use add_to_list instead.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:58 -08:00
Yinghai Lu b592443d90 PCI: add debug print out for add_size
For use in debugging resource reallocation.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:58 -08:00
Yinghai Lu bffc56d411 PCI: make free_list() into a function
After merging struct pci_dev_resource_x and pci_dev_resource,
We can use a function instead of macro now.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:57 -08:00
Yinghai Lu b9b0bba96c PCI: Rename dev_res_x to add_res or fail_res
Linus says don't use dev_res_x because it doesn't communicate anything
about usage.  Rename them to add_res or fail_res etc according to
context.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:57 -08:00
Yinghai Lu 764242a0ae PCI: Merge pci_dev_resource_x and pci_dev_resource
pci_dev_resource_x is a superset of pci_dev_resource and they're just
temp structs used during resource reallocation.

pci_dev_resource usage is quite limted.

So just use pci_dev_resource_x, and rename it as new pci_dev_resource.

-v2: According to Linus, Separate free_list change to another patch

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:56 -08:00
Yinghai Lu bdc4abecae PCI: Replace resource_list with generic list
So we can use helper functions for generic list.  This makes the
resource re-allocation code much more readable.

-v2: Use list_add_tail instead of adding list_insert_before, Pointed out
     by Linus.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:55 -08:00
Yinghai Lu 2934a0de09 PCI: Move struct resource_list to setup-bus.c
No user outside of setup-bus.c now.  Later patches will convert
resource_list to a regular list.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:55 -08:00
Yinghai Lu 78c3b329b9 PCI: Move pdev_sort_resources() to setup-bus.c
This allows us to move the definition of struct resource_list to
setup_bus.c and later convert resource_list to a regular list.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:54 -08:00
Yinghai Lu 19aa7ee432 PCI: make re-allocation try harder by reassigning ranges higher in the heirarchy
On a system with devices that support SRIOV connected to a pcie switch
to pcie root port:

 +-[0000:80]-+-00.0-[81-8f]--
 |           +-01.0-[90-9f]--
 |           +-02.0-[a0-af]----00.0-[a1-a3]--+-02.0-[a2]--+-00.0 Oracle Corporation Device 207a
 |           |                               \-03.0-[a3]--+-00.0 Oracle Corporation Device 207a
 |           +-02.2-[b0-bf]----00.0-[b1-b3]--+-02.0-[b2]--+-00.0 Oracle Corporation Device 207a
 |           |                               \-03.0-[b3]--+-00.0 Oracle Corporation Device 207a

When the BIOS does not assign resources for SRIOV BARs, kernel pci
reallocation only goes up one bridge and then gives up, failing to to
get resources for all sSRIOV BARs, even though the range is large enough
in the peer root bus.

Specifically, only the bridge at the a1:02.0 level has its resources
cleared and reallocated.  The kernel does not go up to clear the bridge
at the 80:02.0 level.

To make it go to upper levels, during retry, we need to treat "good to have"
resources as "must have".

Only on the last try will we treat good to have resources as optional.
At that time, parent bridge resources will already have been released so
we'll have a chance to get everything assigned with must_have plus
good_to_have for all child devices.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:54 -08:00
Yinghai Lu 9b03088f95 PCI: Make pci_rescan_bus handle add_list
This allows us to allocate resources to hotplug bridges during
remove/rescan.

We need to move the function to setup-bus.c so it can use
__pci_bus_size_bridges and __pci_bus_assign_resources directly to take
the add_list resource tracking list.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:53 -08:00
Yinghai Lu 2f320521a0 PCI: Make rescan bus increase bridge resource size if needed
Current rescan will not touch bridge MMIO and IO.

Try to reuse pci_assign_unassigned_bridge_resources(bridge) to update bridge
resources, if child devices need more resources.

Only do that for bridges whose children are all removed already; i.e. don't
release resources that could already be in use by drivers on child devices.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:53 -08:00
Yinghai Lu 8424d7592e PCI: Use add_list in pcie hotplug path.
We need add size for hot plug path when pluging in hotplug chassis
without cards.

-v2: change descriptions. make it applicable after "pci: Check bridge
     resources after resource allocation."

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:52 -08:00
Yinghai Lu 3e6e0d8094 PCI: try to assign required+option size first
We found reassignment can not find a range for one resource, even if the
total available range is large enough.

bridge b1:02.0 will need 2M+3M
bridge b1:03.0 will need 2M+3M

so bridge b0:00.0 will get assigned: 4M : [f8000000-f83fffff]
   later is reassigned to 10M : [f8000000-f9ffffff]

b1:02.0 is assigned to 2M : [f8000000-f81fffff]
b1:03.0 is assigned to 2M : [f8200000-f83fffff]

After that b1:03.0 get chance to be reassigned to [f8200000-f86fffff],
but b1:02.0 will not have chance to expand, because b1:03.0 is using in
middle one.

[  187.911401] pci 0000:b1:02.0: bridge window [mem 0x00100000-0x002fffff] to [bus b2-b2] add_size 300000
[  187.920764] pci 0000:b1:03.0: bridge window [mem 0x00100000-0x002fffff] to [bus b3-b3] add_size 300000
[  187.930129] pci 0000:b1:02.0: [mem 0x00100000-0x002fffff] get_res_add_size  add_size 300000
[  187.938500] pci 0000:b1:03.0: [mem 0x00100000-0x002fffff] get_res_add_size  add_size 300000
[  187.946857] pci 0000:b0:00.0: bridge window [mem 0x00100000-0x004fffff] to [bus b1-b3] add_size 600000
[  187.956206] pci 0000:b0:00.0: BAR 14: assigned [mem 0xf8000000-0xf83fffff]
[  187.963102] pci 0000:b0:00.0: BAR 15: assigned [mem 0xf5000000-0xf51fffff pref]
[  187.970434] pci 0000:b0:00.0: BAR 14: reassigned [mem 0xf8000000-0xf89fffff]
[  187.977497] pci 0000:b1:02.0: BAR 14: assigned [mem 0xf8000000-0xf81fffff]
[  187.984383] pci 0000:b1:02.0: BAR 15: assigned [mem 0xf5000000-0xf50fffff pref]
[  187.991695] pci 0000:b1:03.0: BAR 14: assigned [mem 0xf8200000-0xf83fffff]
[  187.998576] pci 0000:b1:03.0: BAR 15: assigned [mem 0xf5100000-0xf51fffff pref]
[  188.005888] pci 0000:b1:03.0: BAR 14: reassigned [mem 0xf8200000-0xf86fffff]
[  188.012939] pci 0000:b1:02.0: BAR 14: can't assign mem (size 0x200000)
[  188.019471] pci 0000:b1:02.0: failed to add 300000 to res=[mem 0xf8000000-0xf81fffff]
[  188.027326] pci 0000:b2:00.0: reg 184: [mem 0x00000000-0x00003fff 64bit]
[  188.034071] pci 0000:b2:00.0: reg 18c: [mem 0x00000000-0x000fffff 64bit]
[  188.040795] pci 0000:b2:00.0: BAR 2: assigned [mem 0xf8000000-0xf80fffff 64bit]
[  188.048119] pci 0000:b2:00.0: BAR 2: set to [mem 0xf8000000-0xf80fffff 64bit] (PCI address [0xf8000000-0xf80fffff])
[  188.058550] pci 0000:b2:00.0: BAR 6: assigned [mem 0xf5000000-0xf50fffff pref]
[  188.065802] pci 0000:b2:00.0: BAR 0: assigned [mem 0xf8100000-0xf8103fff 64bit]
[  188.073125] pci 0000:b2:00.0: BAR 0: set to [mem 0xf8100000-0xf8103fff 64bit] (PCI address [0xf8100000-0xf8103fff])
[  188.083596] pci 0000:b2:00.0: reg 18c: [mem 0x00000000-0x000fffff 64bit]
[  188.090310] pci 0000:b2:00.0: BAR 9: can't assign mem (size 0x300000)
[  188.096773] pci 0000:b2:00.0: reg 184: [mem 0x00000000-0x00003fff 64bit]
[  188.103479] pci 0000:b2:00.0: BAR 7: assigned [mem 0xf8104000-0xf810ffff 64bit]
[  188.110801] pci 0000:b2:00.0: BAR 7: set to [mem 0xf8104000-0xf810ffff 64bit] (PCI address [0xf8104000-0xf810ffff])
[  188.121256] pci 0000:b1:02.0: PCI bridge to [bus b2-b2]
[  188.126512] pci 0000:b1:02.0:   bridge window [mem 0xf8000000-0xf81fffff]
[  188.133328] pci 0000:b1:02.0:   bridge window [mem 0xf5000000-0xf50fffff pref]
[  188.140608] pci 0000:b3:00.0: reg 184: [mem 0x00000000-0x00003fff 64bit]
[  188.147341] pci 0000:b3:00.0: reg 18c: [mem 0x00000000-0x000fffff 64bit]
[  188.154076] pci 0000:b3:00.0: BAR 2: assigned [mem 0xf8200000-0xf82fffff 64bit]
[  188.161417] pci 0000:b3:00.0: BAR 2: set to [mem 0xf8200000-0xf82fffff 64bit] (PCI address [0xf8200000-0xf82fffff])
[  188.171865] pci 0000:b3:00.0: BAR 6: assigned [mem 0xf5100000-0xf51fffff pref]
[  188.179090] pci 0000:b3:00.0: BAR 0: assigned [mem 0xf8300000-0xf8303fff 64bit]
[  188.186431] pci 0000:b3:00.0: BAR 0: set to [mem 0xf8300000-0xf8303fff 64bit] (PCI address [0xf8300000-0xf8303fff])
[  188.196884] pci 0000:b3:00.0: reg 18c: [mem 0x00000000-0x000fffff 64bit]
[  188.203591] pci 0000:b3:00.0: BAR 9: assigned [mem 0xf8400000-0xf86fffff 64bit]
[  188.210909] pci 0000:b3:00.0: BAR 9: set to [mem 0xf8400000-0xf86fffff 64bit] (PCI address [0xf8400000-0xf86fffff])
[  188.221379] pci 0000:b3:00.0: reg 184: [mem 0x00000000-0x00003fff 64bit]
[  188.228089] pci 0000:b3:00.0: BAR 7: assigned [mem 0xf8304000-0xf830ffff 64bit]
[  188.235407] pci 0000:b3:00.0: BAR 7: set to [mem 0xf8304000-0xf830ffff 64bit] (PCI address [0xf8304000-0xf830ffff])
[  188.245843] pci 0000:b1:03.0: PCI bridge to [bus b3-b3]
[  188.251107] pci 0000:b1:03.0:   bridge window [mem 0xf8200000-0xf86fffff]
[  188.257922] pci 0000:b1:03.0:   bridge window [mem 0xf5100000-0xf51fffff pref]
[  188.265180] pci 0000:b0:00.0: PCI bridge to [bus b1-b3]
[  188.270443] pci 0000:b0:00.0:   bridge window [mem 0xf8000000-0xf89fffff]
[  188.277250] pci 0000:b0:00.0:   bridge window [mem 0xf5000000-0xf51fffff pref]
[  188.284512] pcieport 0000:80:02.2: PCI bridge to [bus b0-bf]
[  188.290184] pcieport 0000:80:02.2:   bridge window [io  0xa000-0xbfff]
[  188.296735] pcieport 0000:80:02.2:   bridge window [mem 0xf8000000-0xf8ffffff]
[  188.303963] pcieport 0000:80:02.2:   bridge window [mem 0xf5000000-0xf5ffffff 64bit pref]

Thus b2:00.0 BAR 9 does not get assigned...

root cause:
b1:02.0 can not be added more range, because b1:03.0 is just after it;
no space between the required ranges.

Solution:
Try to assign required + optional all together at first, and if that
fails, try again with just the required resources.

-v2: seperate add_to_list change() to another patch according to Jesse.
     seperate get_res_add_size() moving to another patch according to Jesse.
     add !realloc_head->next check if the list is empty to bail early
     according to Jesse.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:52 -08:00
Yinghai Lu 1c372353e9 PCI: Move get_res_add_size() function
Need to call it from __assign_resources_sorted() later and we'd like to
avoid a forward declaraion.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:51 -08:00
Yinghai Lu ef62dfefa9 PCI: Make add_to_list() return status
Will be used for resource_list_x duplication when trying
requested+optional at first.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:51 -08:00
Yinghai Lu a4ac9fea01 PCI : Calculate right add_size
During debug of one SRIOV enabled hotplug device, we found found that
add_size is not passed properly.

The device has devices under two level bridges:

 +-[0000:80]-+-00.0-[81-8f]--
 |           +-01.0-[90-9f]--
 |           +-02.0-[a0-af]----00.0-[a1-a3]--+-02.0-[a2]--+-00.0  Oracle Corporation Device
 |           |                               \-03.0-[a3]--+-00.0  Oracle Corporation Device

Which means later the parent bridge will not try to add a big enough range:

[  557.455077] pci 0000:a0:00.0: BAR 14: assigned [mem 0xf9000000-0xf93fffff]
[  557.461974] pci 0000:a0:00.0: BAR 15: assigned [mem 0xf6000000-0xf61fffff pref]
[  557.469340] pci 0000:a1:02.0: BAR 14: assigned [mem 0xf9000000-0xf91fffff]
[  557.476231] pci 0000:a1:02.0: BAR 15: assigned [mem 0xf6000000-0xf60fffff pref]
[  557.483582] pci 0000:a1:03.0: BAR 14: assigned [mem 0xf9200000-0xf93fffff]
[  557.490468] pci 0000:a1:03.0: BAR 15: assigned [mem 0xf6100000-0xf61fffff pref]
[  557.497833] pci 0000:a1:03.0: BAR 14: can't assign mem (size 0x200000)
[  557.504378] pci 0000:a1:03.0: failed to add optional resources res=[mem 0xf9200000-0xf93fffff]
[  557.513026] pci 0000:a1:02.0: BAR 14: can't assign mem (size 0x200000)
[  557.519578] pci 0000:a1:02.0: failed to add optional resources res=[mem 0xf9000000-0xf91fffff]

It turns out we did not calculate size1 properly.

static resource_size_t calculate_memsize(resource_size_t size,
                resource_size_t min_size,
                resource_size_t size1,
                resource_size_t old_size,
                resource_size_t align)
{
        if (size < min_size)
                size = min_size;
        if (old_size == 1 )
                old_size = 0;
        if (size < old_size)
                size = old_size;
        size = ALIGN(size + size1, align);
        return size;
}

We should not pass add_size with min_size in calculate_memsize since
that will make add_size not contribute final add_size.

So just pass add_size with size1 to calculate_memsize().

With this change, we should have chance to remove extra addon in
pci_reassign_resource.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:50 -08:00
Masanari Iida 0dea210b17 PCI: Fix typo in setup-res.c
Correct spelling "resouce" to "resource" in
dricers/pci/setup-res.c

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:50 -08:00
Konrad Rzeszutek Wilk 1160831803 xen/pciback: Support pci_reset_function, aka FLR or D3 support.
We use the __pci_reset_function_locked to perform the action.
Also on attaching ("bind") and detaching ("unbind") we save and
restore the configuration states. When the device is disconnected
from a guest we use the "pci_reset_function" to also reset the
device before being passed to another guest.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:49 -08:00
Konrad Rzeszutek Wilk 6fbf9e7a90 PCI: Introduce __pci_reset_function_locked to be used when holding device_lock.
The use case of this is when a driver wants to call FLR when a device
is attached to it using the SysFS "bind" or "unbind" functionality.

The call chain when a user does "bind" looks as so:

 echo "0000:01.07.0" > /sys/bus/pci/drivers/XXXX/bind

and ends up calling:
  driver_bind:
    device_lock(dev);  <=== TAKES LOCK
    XXXX_probe:
         .. pci_enable_device()
         ...__pci_reset_function(), which calls
                 pci_dev_reset(dev, 0):
                        if (!0) {
                                device_lock(dev) <==== DEADLOCK

The __pci_reset_function_locked function allows the the drivers
'probe' function to call the "pci_reset_function" while still holding
the driver mutex lock.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:48 -08:00
Julia Lawall 8f0cdddcd3 PCI: drivers/pci/hotplug/ibmphp_ebda.c: add missing iounmap
Add missing iounmap in error handling code, in a case where the function
already preforms iounmap on some other execution path.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e;
statement S,S1;
int ret;
@@
e = \(ioremap\|ioremap_nocache\)(...)
... when != iounmap(e)
if (<+...e...+>) S
... when any
    when != iounmap(e)
*if (...)
   { ... when != iounmap(e)
     return ...; }
... when any
iounmap(e);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:47 -08:00
Amos Kong f382a086f3 PCI: Can continually add funcs after adding func0
Boot up a KVM guest, and hotplug multifunction
devices(func1,func2,func0,func3) to guest.

for i in 1 2 0 3;do
qemu-img create /tmp/resize$i.qcow2 1G -f qcow2
(qemu) drive_add 0x11.$i id=drv11$i,if=none,file=/tmp/resize$i.qcow2
(qemu) device_add virtio-blk-pci,id=dev11$i,drive=drv11$i,addr=0x11.$i,multifunction=on
done

In linux kernel, when func0 of the slot is hot-added, the whole
slot will be marked as 'enabled', then driver will ignore other new
hotadded funcs.
But in Win7 & WinXP, we can continaully add other funcs after adding
func0, all funcs will be added in guest.

drivers/pci/hotplug/acpiphp_glue.c:
static int acpiphp_check_bridge(struct acpiphp_bridge *bridge)
{
....
        for (slot = bridge->slots; slot; slot = slot->next) {
                if (slot->flags & SLOT_ENABLED) {
                        acpiphp_disable_slot()
                else
                        acpiphp_enable_slot()
....                              |
}                                 v
                            enable_device()
                                  |
                                  v
        //only don't enable slot if func0 is not added
	list_for_each_entry(func, &slot->funcs, sibling) {
               ...
        }
       slot->flags |= SLOT_ENABLED; //mark slot to 'enabled'

This patch just make pci driver can continaully add funcs after adding
func 0. Only mark slot to 'enabled' when all funcs are added.

For pci multifunction hotplug, we can add functions one by one(func 0 is
necessary), and all functions will be removed in one time.

Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-02-14 08:44:47 -08:00