For a subtractive decode bridge, we previously added and printed all
resources of the primary bus, even if they were not valid.  In the example
below, the bridge 00:1c.3 has no windows enabled, so there are no valid
resources on bus 02.  But since 02:00.0 is subtractive decode bridge, we
add and print all those invalid resources, which don't really make sense:

  pci 0000:00:1c.3: PCI bridge to [bus 02-03]
  pci 0000:02:00.0: PCI bridge to [bus 03] (subtractive decode)
  pci 0000:02:00.0:   bridge window [??? 0x00000000 flags 0x0] (subtractive decode)

Add and print the subtractively-decoded resources only if they are valid.

There's an example in the dmesg log attached to the bugzilla below (but
this patch doesn't fix the bug reported there).

Link: https://bugzilla.kernel.org/show_bug.cgi?id=73141Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

If the console is a PCI device, and we try to print to it while its
decoding is disabled, the system will hang.  This particular printk hasn't
caused a problem yet, but it could, so this fixes it.

See also 0ff9514b ("PCI: Don't print anything while decoding is
disabled").
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

If a BAR is above 4GB and our dma_addr_t is too small, don't clear the BAR
to zero: that doesn't disable the BAR, and it makes it more likely that the
BAR will conflict with things if we turn on the memory enable bit (as we
will at "out:" if the device was already enabled at the handoff).

We should also print the BAR info and its original size so we can follow
the process when we try to assign space to it.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

If dma_addr_t is too small to represent the BAR value,
pcibios_bus_to_resource() will fail, so just remember the BAR size directly
in the resource.  The resource is already marked UNSET, so we know the
address isn't valid anyway.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

We can only handle BARs above 4GB if dma_addr_t (not resource_size_t) is 64
bits wide.  If we have a 64-bit resource_size_t and a 32-bit dma_addr_t,
we can't deal with BARs above 4GB.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

We can only handle BARs larger than 4GB if both dma_addr_t and
resource_size_t are 64 bits wide.  If dma_addr_t is 32 bits, we can't
represent all the bus addresses, and if resource_size_t is 32 bits, we
can't represent all the CPU addresses.

Previously we cleared res->flags (at "fail:") for resources that were too
large.  That means we think the BAR doesn't exist at all, which in turn
means that we could enable the device even though we can't keep track of
where the BAR is and we can't make sure it doesn't overlap something else.

This preserves the type flags (MEM/IO) so we can keep from enabling the
device.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Make a note in dmesg when we overwrite legacy IDE BAR info.  We previously
logged something like this:

  pci 0000:00:1f.1: reg 0x10: [io  0x0000-0x0007]

and then silently overwrote the resource.  There's an example in the
bugzilla below.  This doesn't fix the bugzilla; it just makes what's going
on more obvious.

No functional change; merely adds some dev_info() calls.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=48451Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

If we don't support 64-bit addresses, i.e., CONFIG_PHYS_ADDR_T_64BIT is not
set, we can't deal with BARs above 4GB.  In this case we already pretend
the BAR contained zero; this patch also sets IORESOURCE_UNSET so we can try
to reallocate it later.

I don't think this is exactly correct: what we care about here are *bus*
addresses, not CPU addresses, so the tests of sizeof(resource_size_t)
probably should be on sizeof(dma_addr_t) instead.  But this is what's been
in -next, so we'll fix that later.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

When assigning a new bus number in pci_scan_bridge we check whether
max+1 is free by calling pci_find_bus. If it does already exist then we
assume that we are rescanning and that this is the right bus to scan.

This is fragile. If max+1 lies outside of bus->busn_res.end then we will
rescan some random bus from somewhere else in the hierachy. This patch
checks for this case and prints a warning.

[bhelgaas: add parent/child bus number info to dev_warn()]
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

pci_scan_child_bus can (potentially) return a bus number higher than the
subordinate value of the child bus. Possible reasons are that bus numbers
are reserved for SR-IOV or for CardBus (SR-IOV is done without checks and
the CardBus checks are sketchy at best).

We clamp the returned value to the actual subordinate value and print a
warning if too many bus numbers are reserved.

[bhelgaas: whitespace]
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

The function has no effect.

If pcibios_assign_all_busses() is not set then the function does nothing.

If it is set then in pci_scan_bridge we are always in the branch where
we assign the bus numbers ourselves and the subordinate values of all
parent busses will be set to 0xff since that is what they inherited from
their parent bus and ultimately from the root bus.
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Right now we use 0xff for busn_res.end when probing and later reduce it to
the value that is actually used. This does not work if a parent bridge has
already a lower subordinate value. For example during hotplug of a new
bridge below an already-configured bridge the following message is printed
from pci_bus_insert_busn_res():

  pci_bus 0000:06: busn_res: can not insert [bus 06-ff] under [bus 05-9b] (conflicts with (null) [bus 05-9b])

This patch clamps the bus range to that of the parent and also ensures that
we do not exceed the parents range when assigning the final subordinate
value.

We also check that busses configured by the firmware fit into their parents
bounds.

[bhelgaas: reword dev_warn() and fix printk format warning]
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

If a conflict happens during insert_resource_conflict() and all conflicts
fit within the newly inserted resource then they will become children of
the new resource. This is almost certainly not what we want for bus
numbers.
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Right now the CardBus code in pci_scan_bridge() is executed during both
passes. Since we always allocate the bus number ourselves it makes sense
to put it into the second pass.
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Initially when we encountered a bus that was already present we skipped
it. Since 74710ded 'PCI: always scan child buses' we continue
scanning in order to allow user triggered rescans of already existing
busses.

The old comment suggested that the reason for continuing the scan is a
bug in the i450NX chipset. This is not the case.
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

This patch fixes two small issues:
 - If pci_add_new_bus() fails, max must not be incremented. Otherwise
   an incorrect value is returned from pci_scan_bridge().
 - If the bus is already present, max must be incremented. I think
   that this case should only be hit if we trigger a manual rescan of a
   CardBus bridge.
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Revert commit ef83b078 "PCI: Remove from bus_list and release
resources in pci_release_dev()" that made some nasty race conditions
become possible.  For example, if a Thunderbolt link is unplugged
and then replugged immediately, the pci_release_dev() resulting from
the hot-remove code path may be racing with the hot-add code path
which after that commit causes various kinds of breakage to happen
(up to and including a hard crash of the whole system).

Moreover, the problem that commit ef83b078 attempted to address
cannot happen any more after commit 8a4c5c32 "PCI: Check parent
kobject in pci_destroy_dev()", because pci_destroy_dev() will now
return immediately if it has already been executed for the given
device.

Note, however, that the invocation of msi_remove_pci_irq_vectors()
removed by commit ef83b078 from pci_free_resources() along with
the other changes made by it is not added back because of subsequent
code changes depending on that modification.

Fixes: ef83b078 (PCI: Remove from bus_list and release resources in pci_release_dev())
Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There are multiple PCI device addition and removal code paths that may be
run concurrently with the generic PCI bus rescan and device removal that
can be triggered via sysfs.  If that happens, it may lead to multiple
different, potentially dangerous race conditions.

The most straightforward way to address those problems is to run
the code in question under the same lock that is used by the
generic rescan/remove code in pci-sysfs.c.  To prepare for those
changes, move the definition of the global PCI remove/rescan lock
to probe.c and provide global wrappers, pci_lock_rescan_remove()
and pci_unlock_rescan_remove(), allowing drivers to manipulate
that lock.  Also provide pci_stop_and_remove_bus_device_locked()
for the callers of pci_stop_and_remove_bus_device() who only need
to hold the rescan/remove lock around it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Using 'make namespacecheck' identify code which should be declared static.
Checked for users in other driver/archs as well.  Compile tested only.

This stops exporting the following interfaces to modules:

    pci_target_state()
    pci_load_saved_state()

[bhelgaas: retained pci_find_next_ext_capability() and pci_cfg_space_size()]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

My philosophy is unused code is dead code.  And dead code is subject to bit
rot and is a likely source of bugs.  Use it or lose it.

This removes this unused and deprecated interface:

    alloc_pci_dev()

[bhelgaas: split to separate patch]
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

These interfaces:

  pcibios_resource_to_bus(struct pci_dev *dev, *bus_region, *resource)
  pcibios_bus_to_resource(struct pci_dev *dev, *resource, *bus_region)

took a pci_dev, but they really depend only on the pci_bus.  And we want to
use them in resource allocation paths where we have the bus but not a
device, so this patch converts them to take the pci_bus instead of the
pci_dev:

  pcibios_resource_to_bus(struct pci_bus *bus, *bus_region, *resource)
  pcibios_bus_to_resource(struct pci_bus *bus, *resource, *bus_region)

In fact, with standard PCI-PCI bridges, they only depend on the host
bridge, because that's the only place address translation occurs, but
we aren't going that far yet.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Previously we removed the pci_dev from the bus_list and released its
resources in pci_destroy_dev().  But that's too early: it's possible to
call pci_destroy_dev() twice for the same device (e.g., via sysfs), and
that will cause an oops when we try to remove it from bus_list the second
time.

We should remove it from the bus_list only when the last reference to the
pci_dev has been released, i.e., in pci_release_dev().

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

4f535093 ("PCI: Put pci_dev in device tree as early as possible")
moved pci_proc_attach_device() from pci_bus_add_device() to
pci_device_add().

This moves it back to pci_bus_add_device(), essentially reverting that
part of 4f535093.  This makes it symmetric with pci_stop_dev(),
where we call pci_proc_detach_device() and pci_remove_sysfs_dev_files()
and set dev->is_added = 0.

[bhelgaas: changelog, create sysfs then attach proc for symmetry]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Fix whitespace, capitalization, and spelling errors.  No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.

Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus())
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

No one uses "is_pcie" now; remove this obsolete member.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Use pci_is_pcie() instead of pci_find_capability() to simplify code.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

If a BIOS configures MPS incorrectly, devices may not work normally.
For example, if a bridge has MPS set larger than an endpoint below it,
the endpoint may discard packets.

To help diagnose this issue, print a warning if we find an endpoint
MPS setting different than that of the upstream bridge.

[bhelgaas: changelog, "bridge" temporary, warning text]
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60799Reported-by: Joe Jin <joe.jin@oracle.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jon Mason <jdmason@kudzu.us>

Correct minor wording issue in MPS peer-to-peer comment.  Noticed by Don
Dutile.
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

We disable BARs while sizing them so we don't cause conflicts with other
devices (see 253d2e54 and bbffe435).  But if device decoding is already
disabled before we size the BAR, we don't need to disable it again.

[bhelgaas: changelog, add PCI_COMMAND_DECODING_ENABLE for readability]
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

When booting with "pci=pcie_bus_safe", we previously limited the
fabric MPS to 128 when we found:

  (1) A hotplug-capable Downstream Port ("dev->is_hotplug_bridge &&
      pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT"), or

  (2) A hotplug-capable Root Port with a slot that was either empty or
      contained a multi-function device ("dev->is_hotplug_bridge &&
      !list_is_singular(&dev->bus->devices)")

Part (1) is valid, but part (2) is not.

After a hot-add in the slot below a Root Port, we can reconfigure all
MPS values in the fabric below the Root Port because the new device is
the only thing below the Root Port and there are no active drivers.
Therefore, there's no reason to limit the MPS for Root Ports, no
matter what's in the slot.

Test info:

    -+-[0000:40]-+-07.0-[0000:46]--+-00.0  Intel 82576 NIC
                                   \-00.1  Intel 82576 NIC

    0000:40:07.0 Root Port bridge to [bus 46] (MPS supported=256)
    0000:46:00.0 Endpoint                     (MPS supported=512)
    0000:46:00.1 Endpoint                     (MPS supported=512)

    # echo 0 > /sys/bus/pci/slots/7/power
    # echo 1 > /sys/bus/pci/slots/7/power
    pcieport 0000:40:07.0: PCI-E Max Payload Size set to 256/ 256 (was 256)
    pci 0000:46:00.0:      PCI-E Max Payload Size set to 256/ 512 (was 128)
    pci 0000:46:00.1:      PCI-E Max Payload Size set to 256/ 512 (was 128)

Before this change, we set MPS to 128 for the Root Port and both NICs
because the slot contained a multi-function device and

    dev->is_hotplug_bridge && !list_is_singular(&dev->bus->devices)

was true.  After this change, we set it to 256.

[bhelgaas: changelog, comments, split out upstream bridge check]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jon Mason <jdmason@kudzu.us>

PCIe hotplug bridges are always either Root Ports or Downstream Ports.  No
other device type can have a PCIe link leading downstream to a slot.

Root Ports don't have an upstream bridge, so "dev->is_hotplug_bridge &&
dev->bus->self" is true if and only if "dev" is a Downstream Port.  That
means we can simplify this by looking at the type of "dev" itself, without
looking upstream at all.

No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Based on a patch by Jon Mason (see URL below).

All users of pcie_bus_configure_settings() pass arguments of the form
"bus, bus->self->pcie_mpss".  The "mpss" argument is redundant since we
can easily look it up internally.  In addition, all callers check
"bus->self" for NULL, which we can also do internally.

This patch simplifies the interface and the callers.  No functional change.

Reference: http://lkml.kernel.org/r/1317048850-30728-2-git-send-email-mason@myri.comSigned-off-by: Bjorn Helgaas <bhelgaas@google.com>

The conventional spelling is "PCIe", but I think even that is superfluous,
so remove the whole thing.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

The new struct msi_chip is used to associated an MSI controller with a
PCI bus. It is automatically handed down from the root to its children
during bus enumeration.

This patch provides default (weak) implementations for the architecture-
specific MSI functions (arch_setup_msi_irq(), arch_teardown_msi_irq()
and arch_msi_check_device()) which check if a PCI device's bus has an
attached MSI chip and forward the call appropriately.
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Daniel Price <daniel.price@gmail.com>
Tested-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

pcie_link_speed and pcix_bus_speed are arrays used by probe.c to correctly
convert lnksta register values into the pci_bus_speed enum. These static arrays
are useful outside probe for this purpose. This patch makes these defines into
conist arrays and exposes them with an extern header in drivers/pci/pci.h

-v2-
* move extern declarations to drivers/pci/pci.h

CC: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

We currently enable PCI bridges after scanning a bus and assigning
resources.  This is often done in arch code.

This patch changes this so we don't enable a bridge until necessary, i.e.,
until we enable a PCI device behind the bridge.  We do this in the generic
pci_enable_device() path, so this also removes the arch-specific code to
enable bridges.

[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

The dev_attrs field of struct class is going away soon, dev_groups
should be used instead.  This converts the PCI class code to use the
correct field.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Platforms may want to provide architecture-specific functionality when
a pci device is released. Add a pcibios_release_device() call that
architectures can override to do so.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

On allocation failure, return early so the main body of the function
doesn't have to be indented as the body of an "if" statement.  No
functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

This renames pci_release_bus_bridge_dev() to pci_release_host_bridge_dev()
and moves it next to pci_alloc_host_bridge().  No functional change.

[bhelgaas: split rename & move out of create/destroy symmetry patch]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>