Add PCI-specific dev_printk() wrappers and use them to simplify the code
slightly.  No functional change intended.
Signed-off-by: NFrederick Lawler <fred@fredlawl.com>
[bhelgaas: squash into one patch]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

System BIOS sometimes allocates extra bus space for hotplug-capable PCIe
root/downstream ports. This space is needed if the device plugged to the
port will have more hotplug-capable downstream ports. A good example of
this is Thunderbolt. Each Thunderbolt device contains a PCIe switch and
one or more hotplug-capable PCIe downstream ports where the daisy chain
can be extended.

Currently Linux only allocates minimal bus space to make sure all the
enumerated devices barely fit there. The BIOS reserved extra space is
not taken into consideration at all. Because of this we run out of bus
space pretty quickly when more PCIe devices are attached to hotplug
downstream ports in order to extend the chain.

Modify the PCI core so we distribute the available BIOS allocated bus space
equally between hotplug-capable bridges to make sure there is enough bus
space for extending the hierarchy later on.

Update kernel docs of the affected functions.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

One can ask more buses to be reserved for hotplug bridges by passing
pci=hpbussize=N in the kernel command line.  If the parent bus does not
have enough bus space available we incorrectly create child bus with the
requested number of subordinate buses.

In the example below hpbussize is set to one more than we have available
buses in the root port:

  pci 0000:07:00.0: [8086:1578] type 01 class 0x060400
  pci 0000:07:00.0: scanning [bus 00-00] behind bridge, pass 0
  pci 0000:07:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
  pci 0000:07:00.0: scanning [bus 00-00] behind bridge, pass 1
  pci_bus 0000:08: busn_res: can not insert [bus 08-ff] under [bus 07-3f] (conflicts with (null) [bus 07-3f])
  pci_bus 0000:08: scanning bus
  ...
  pci_bus 0000:0a: bus scan returning with max=40
  pci_bus 0000:0a: busn_res: [bus 0a-ff] end is updated to 40
  pci_bus 0000:0a: [bus 0a-40] partially hidden behind bridge 0000:07 [bus 07-3f]
  pci_bus 0000:08: bus scan returning with max=40
  pci_bus 0000:08: busn_res: [bus 08-ff] end is updated to 40

Instead of allowing this, limit the subordinate number to be less than or
equal the maximum subordinate number allocated for the parent bus (if it
has any).
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
[bhelgaas: remove irrelevant dmesg messages]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The current scanning code is really hard to understand because it calls
the same function in a loop where pass value is changed without any
comments explaining it:

  for (pass = 0; pass < 2; pass++)
    for_each_pci_bridge(dev, bus)
      max = pci_scan_bridge(bus, dev, max, pass);

Unfamiliar reader cannot tell easily what is the purpose of this loop
without looking at internals of pci_scan_bridge().

In order to make this bit easier to understand, open-code the loop in
pci_scan_child_bus() and pci_hp_add_bridge() with added comments.

No functional changes intended.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

There is not much point of having a file with a single function in it.
Instead we can just move pci_hp_add_bridge() to drivers/pci/probe.c and
make it available always when PCI core is enabled.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
[bhelgaas: convert printk to dev_err()]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The following pattern is often used:

  list_for_each_entry(dev, &bus->devices, bus_list) {
    if (pci_is_bridge(dev)) {
      ...
    }
  }

Add a for_each_pci_bridge() helper to make that code easier to write and
read by reducing indentation level.  It also saves one or few lines of code
in each occurrence.

Convert PCI core parts here at the same time.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
[bhelgaas: fold in http://lkml.kernel.org/r/20171013165352.25550-1-andriy.shevchenko@linux.intel.com]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Add a print statement in pci_bus_wait_crs() so that user observes the
progress of device polling instead of silently waiting for timeout to be
reached.
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
[bhelgaas: check for timeout first so we don't print "waiting, giving up",
always print time we've slept (not the actual timeout, print a "ready"
message if we've printed a "waiting" message]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Configuration Request Retry Status (CRS) was previously hidden inside
pci_bus_read_dev_vendor_id().  We want to add support for CRS in other
situations, such as waiting for a device to become ready after a Function
Level Reset.

Move CRS handling into pci_bus_wait_crs() so it can be called from other
places.
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
[bhelgaas: pass pointer, not value, to pci_bus_wait_crs() so caller gets
correct Vendor ID]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Add pci_bus_crs_vendor_id() to determine whether data returned for a config
read of the Vendor ID indicates a Configuration Request Retry Status (CRS)
response.

Per PCIe r3.1, sec 2.3.2, this data is only returned if:

  - CRS Software Visibility is enabled,
  - a config read includes both bytes of the Vendor ID, and
  - the read receives a CRS completion
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
[bhelgaas: changelog, change name to pci_bus_crs_vendor_id(), make static
in probe.c, use it in pci_bus_read_dev_vendor_id()]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

While waiting for a device to become ready (i.e., to return a non-CRS
completion to a read of its Vendor ID), if we got a valid response to the
very last read before timing out, we printed a warning and gave up on the
device even though it was actually ready.

For a typical 60s timeout, we wait about 65s (it's not exact because of the
exponential backoff), but we treated devices that became ready between 33s
and 65s as though they failed.

Move the Device ID read later so we check whether the device is ready
before checking for a timeout.

Thanks to Sinan Kaya <okaya@codeaurora.org>, reorder reads so we always
check device presence after sleep, since it's pointless to sleep unless we
recheck afterwards.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

When bit4 is set in the PCIe Device Control register, it indicates
whether the device is permitted to use relaxed ordering.
On some platforms using relaxed ordering can have performance issues or
due to erratum can cause data-corruption. In such cases devices must avoid
using relaxed ordering.

The patch adds a new flag PCI_DEV_FLAGS_NO_RELAXED_ORDERING to indicate that
Relaxed Ordering (RO) attribute should not be used for Transaction Layer
Packets (TLP) targeted towards these affected root complexes.

This patch checks if there is any node in the hierarchy that indicates that
using relaxed ordering is not safe. In such cases the patch turns off the
relaxed ordering by clearing the capability for this device.
Signed-off-by: NCasey Leedom <leedom@chelsio.com>
Signed-off-by: NDing Tianhong <dingtianhong@huawei.com>
Acked-by: NAshok Raj <ashok.raj@intel.com>
Acked-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: NCasey Leedom <leedom@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Multiple architectures define this as an empty function, and I'm adding
another one as part of the RISC-V port.  Add a __weak version of
pcibios_fixup_bus() and delete the now-obselete ones in a handful of
ports.

The only functional change should be that microblaze used to export
pcibios_fixup_bus().  None of the other architectures exports this, so I
just dropped it.
Signed-off-by: NPalmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Per PCIe r3.1, sec 2.2.6.2 and 7.8.4, a Requester may not use 8-bit Tags
unless its Extended Tag Field Enable is set, but all Receivers/Completers
must handle 8-bit Tags correctly regardless of their Extended Tag Field
Enable.

Some devices do not handle 8-bit Tags as Completers, so add a quirk for
them.  If we find such a device, we disable Extended Tags for the entire
hierarchy to make peer-to-peer DMA possible.

The Broadcom HT2100 seems to have issues with handling 8-bit tags.  Mark it
as broken.

The pci_walk_bus() in the quirk handles devices we've enumerated in the
past, and pci_configure_device() handles devices we enumerate in the
future.

Fixes: 60db3a4d ("PCI: Enable PCIe Extended Tags if supported")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1467674Reported-and-tested-by: NWim ten Have <wim.ten.have@oracle.com>
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
[bhelgaas: changelog, tweak messages, rename bit and quirk]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The pci_scan_root_bus_bridge() function allows passing a parameterized
struct pci_host_bridge and scanning the resulting PCI bus; since the struct
msi_controller is part of the struct pci_host_bridge and the struct
pci_host_bridge can now be passed to pci_scan_root_bus_bridge() explicitly,
there is no need for a scan interface with a MSI controller parameter.

With all PCI host controller drivers and platform code relying on
pci_scan_root_bus_msi() converted over to pci_scan_root_bus_bridge() the
pci_scan_root_bus_msi() becomes obsolete and can be removed.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

John reported that an Intel QuickAssist crypto accelerator didn't work in a
Dell PowerEdge R730.  The problem seems to be that we enabled ECRC when the
device doesn't support it:

  85:00.0 Co-processor [0b40]: Intel Corporation DH895XCC Series QAT [8086:0435]
    Capabilities: [100 v1] Advanced Error Reporting
      AERCap: First Error Pointer: 00, GenCap- CGenEn+ ChkCap- ChkEn+

1302fcf0 ("PCI: Configure *all* devices, not just hot-added ones")
exposed the problem because it applies settings from the _HPX method to all
devices, not just hot-added ones.  The R730 supplies an _HPX method that
allows the kernel to enable ECRC.

Only enable ECRC if the device advertises support for it.

Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1571798
Fixes: 1302fcf0 ("PCI: Configure *all* devices, not just hot-added ones")
Reported-by: NJohn Mazzie <john_mazzie@dell.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

With the introduction of pci_scan_root_bus_bridge() there is no need to
export pci_register_host_bridge() to other kernel subsystems other than the
PCI compilation unit that needs it.

Make pci_register_host_bridge() static to its compilation unit and convert
the existing drivers usage over to pci_scan_root_bus_bridge().
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>

The current pci_scan_root_bus() interface is made up of two main code
paths:

  - pci_create_root_bus()
  - pci_scan_child_bus()

pci_create_root_bus() is a wrapper function that allows to create a struct
pci_host_bridge structure, initialize it with the passed parameters and
register it with the kernel.

As the struct pci_host_bridge require additional struct members,
pci_create_root_bus() parameters list has grown in time, making it unwieldy
to add further parameters to it in case the struct pci_host_bridge gains
more members fields to augment its functionality.

Since PCI core code provides functions to allocate struct pci_host_bridge,
instead of forcing the pci_create_root_bus() interface to add new
parameters to cater for new struct pci_host_bridge functionality, it is
more suitable to add an interface in PCI core code to scan a PCI bus
straight from a struct pci_host_bridge created and customized by each
specific PCI host controller driver.

Add a pci_scan_root_bus_bridge() function to allow PCI host controller
drivers to create and initialize struct pci_host_bridge and scan the
resulting bus.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>

Struct pci_host_bridge can be allocated by PCI host bridge drivers which
usually allocate and map memory through devm managed interfaces.

Add a devm version for the pci_alloc_host_bridge() interface to simplify
PCI host controller driver porting and simplify the driver failure paths.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>

Commit a52d1443 ("PCI: Export host bridge registration interface")
exported the pci_alloc_host_bridge() interface so that PCI host controllers
drivers can make use of it.

Introduce pci_alloc_host_bridge() kernel counterpart to free the host
bridge data structures, pci_free_host_bridge(), export it and update kernel
functions releasing host bridge objects allocated memory to make use of it.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>

The introduction of pci_register_host_bridge() kernel interface allows PCI
host controller drivers to create the struct pci_host_bridge object,
initialize it and register it with the kernel so that its corresponding PCI
bus can be scanned and its devices probed.

The host bridge device release function pci_release_host_bridge_dev() is a
static function common for all struct pci_host_bridge allocated objects, so
in its current form cannot be used by PCI host bridge controllers drivers
to initialize the allocated struct pci_host_bridge, which leaves struct
pci_host_bridge devices release function uninitialized.

Since pci_release_host_bridge_dev() is a function common to all PCI host
bridge objects, initialize it in pci_alloc_host_bridge() (ie common host
bridge allocation interface) so that all struct pci_host_bridge objects
have their release function initialized by default at allocation time,
removing the need for exporting the common pci_release_host_bridge_dev()
function to other compilation units.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>

The test for INTx masking via PCI_COMMAND_INTX_DISABLE performed in
pci_intx_mask_supported() should be done before the device can be used.
This is to avoid writing PCI_COMMAND while the driver owns the device, in
case that has any effect on MSI/MSI-X interrupts.

Move the content of pci_intx_mask_supported() to pci_intx_mask_broken() and
call it from pci_setup_device().

The test result can be queried at any time later using the same
pci_intx_mask_supported() interface as before (though with changed
implementation), so callers (uio, vfio) should be unaffected.
Signed-off-by: NPiotr Gregor <piotrgregor@rsyncme.org>
[bhelgaas: changelog, remove quirk check, remove locking, move
dev->broken_intx_masking assignment to caller]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>

Configuring DMA ops at probe time will allow deferring device probe when
the IOMMU isn't available yet. The dma_configure for the device is
now called from the generic device_attach callback just before the
bus/driver probe is called. This way, configuring the DMA ops for the
device would be called at the same place for all bus_types, hence the
deferred probing mechanism should work for all buses as well.

pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
       |                         |
pci_bus_add_device     (device_add/driver_register)
       |                         |
device_attach           device_initial_probe
       |                         |
__device_attach_driver    __device_attach_driver
       |
driver_probe_device
       |
really_probe
       |
dma_configure

Similarly on the device/driver_unregister path __device_release_driver is
called which inturn calls dma_deconfigure.

This patch changes the dma ops configuration to probe time for
both OF and ACPI based platform/amba/pci bus devices.
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: NHanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci part)
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NSricharan R <sricharan@codeaurora.org>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

A 64-bit value is not needed since a PCI ROM address consists in 32 bits.
This fixes a clang warning about "implicit conversion from 'unsigned long'
to 'u32'".

Also remove now unnecessary casts to u32 from __pci_read_base() and
pci_std_update_resource().
Signed-off-by: NMatthias Kaehlcke <mka@chromium.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Local variables 'l' and 'sz' are uninitialized.  Normally, they would
be initialized by pci_read_config_dword() but when an error occurs,
some drivers immediately return an error code, which leaves the
argument uninitialized.

Provide a safe initial value to make the code more robust.
Signed-off-by: NMarc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Detect on probe whether a PCI device is part of a Thunderbolt controller.
Intel uses a Vendor-Specific Extended Capability (VSEC) with ID 0x1234
on such devices.  Detect presence of this VSEC and cache it in a newly
added is_thunderbolt bit in struct pci_dev.

Also, add a helper to check whether a given PCI device is situated on a
Thunderbolt daisy chain (i.e., below a PCI device with is_thunderbolt
set).

The necessity arises from the following:

* If an external Thunderbolt GPU is connected to a dual GPU laptop,
  that GPU is currently registered with vga_switcheroo even though it
  can neither drive the laptop's panel nor be powered off by the
  platform.  To vga_switcheroo it will appear as if two discrete
  GPUs are present.  As a result, when the external GPU is runtime
  suspended, vga_switcheroo will cut power to the internal discrete GPU
  which may not be runtime suspended at all at this moment.  The
  solution is to not register external GPUs with vga_switcheroo, which
  necessitates a way to recognize if they're on a Thunderbolt daisy
  chain.

* Dual GPU MacBook Pros introduced 2011+ can no longer switch external
  DisplayPort ports between GPUs.  (They're no longer just used for DP
  but have become combined DP/Thunderbolt ports.)  The driver to switch
  the ports, drivers/platform/x86/apple-gmux.c, needs to detect presence
  of a Thunderbolt controller and, if found, keep external ports
  permanently switched to the discrete GPU.

v2: Make kerneldoc for pci_is_thunderbolt_attached() more precise,
    drop portion of commit message pertaining to separate series.
    (Bjorn Helgaas)

Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Amir Levy <amir.jer.levy@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Link: http://patchwork.freedesktop.org/patch/msgid/0ab165a4a35c0b60f29d4c306c653ead14fcd8f9.1489145162.git.lukas@wunner.de

Every PCIe device can generate 5-bit transaction Tags, which allow up to 32
concurrent requests.  Some devices can generate 8-bit Extended Tags, which
allow up to 256 concurrent requests.

Per the ECN mentioned below, all PCIe Receivers are expected to support
Extended Tags, so devices are allowed (but not required) to enable them by
default.

If a device supports Extended Tags but does not enable them by default,
enable them.  This allows the device to have up to 256 outstanding
transactions at a time, which may improve performance.

[bhelgaas: changelog, check for PCIe device]
Link: https://pcisig.com/sites/default/files/specification_documents/ECN_Extended_Tag_Enable_Default_05Sept2008_final.pdfSigned-off-by: NSinan Kaya <okaya@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

A PCI-to-PCIe bridge (a "reverse bridge") has a PCI or PCI-X primary
interface and a PCI Express secondary interface.  The PCIe interface is a
Downstream Port that originates a Link.  See the "PCI Express to PCI/PCI-X
Bridge Specification", rev 1.0, sections 1.2 and A.6.

The bug report below involves a PCI-to-PCIe bridge and a PCIe switch below
the bridge:

  00:1e.0 Intel 82801 PCI Bridge to [bus 01-0a]
  01:00.0 Pericom PI7C9X111SL PCIe-to-PCI Reversible Bridge to [bus 02-0a]
  02:00.0 Pericom Device 8608 [PCIe Upstream Port] to [bus 03-0a]
  03:01.0 Pericom Device 8608 [PCIe Downstream Port] to [bus 0a]

01:00.0 is configured as a PCI-to-PCIe bridge (despite the name printed by
lspci).  As we traverse a PCIe hierarchy, device connections alternate
between PCIe Links and internal Switch logic.  Previously we did not
recognize that 01:00.0 had a secondary link, so we thought the 02:00.0
Upstream Port *did* have a secondary link.  In fact, it's the other way
around: 01:00.0 has a secondary link, and 02:00.0 has internal Switch logic
on its secondary side.

When we thought 02:00.0 had a secondary link, the pci_scan_slot() ->
only_one_child() path assumed 02:00.0 could have only one child, so 03:00.0
was the only possible downstream device.  But 03:00.0 doesn't exist, so we
didn't look for any other devices on bus 03.

Booting with "pci=pcie_scan_all" is a workaround, but we don't want users
to have to do that.

Recognize that PCI-to-PCIe bridges originate links on their secondary
interfaces.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=189361
Fixes: d0751b98 ("PCI: Add dev->has_secondary_link to track downstream PCIe links")
Tested-by: NBlake Moore <blake.moore@men.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org	# v4.2+

Previously we didn't check the type of device before trying to apply Type 1
(PCI-X) or Type 2 (PCIe) Setting Records from _HPX.

We don't support PCI-X Setting Records, so this was harmless, but the
warning was useless.

We do support PCIe Setting Records, and we didn't check whether a device
was PCIe before applying settings.  I don't think anything bad happened on
non-PCIe devices because pcie_capability_clear_and_set_word(),
pcie_cap_has_lnkctl(), etc., would fail before doing any harm.  But it's
ugly to depend on those internals.

Check the device type before attempting to apply Type 1 and Type 2 Setting
Records (Type 0 records are applicable to PCI, PCI-X, and PCIe devices).

A side benefit is that this prevents useless "not supported" warnings when
a BIOS supplies a Type 1 (PCI-X) Setting Record and we try to apply it to
every single device:

  pci 0000:00:00.0: PCI-X settings not supported

After this patch, we'll get the warning only when a BIOS supplies a Type 1
record and we have a PCI-X device to which it should be applied.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=187731Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Allow PCI host bridge drivers to use the new host bridge interfaces to
register their host bridge.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <helgaas@kernel.org>

Provide a way to allocate driver-specific data along with a PCI host bridge
structure. The bridge's ->private field points to this data.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <helgaas@kernel.org>

Make the existing pci_host_bridge structure a proper device that is usable
by PCI host drivers in a more standard way. In addition to the existing
pci_scan_bus(), pci_scan_root_bus(), pci_scan_root_bus_msi(), and
pci_create_root_bus() interfaces, this unfortunately means having to add
yet another interface doing basically the same thing, and add some extra
code in the initial step.

However, this time it's more likely to be extensible enough that we won't
have to do another one again in the future, and we should be able to reduce
code much more as a result.

The main idea is to pull the allocation of 'struct pci_host_bridge' out of
the registration, and let individual host drivers and architecture code
fill the members before calling the registration function.

There are a number of things we can do based on this:

* Use a single memory allocation for the driver-specific structure
  and the generic PCI host bridge
* consolidate the contents of driver-specific structures by moving
  them into pci_host_bridge
* Add a consistent interface for removing a PCI host bridge again
  when unloading a host driver module
* Replace the architecture specific __weak pcibios_*() functions with
  callbacks in a pci_host_bridge device
* Move common boilerplate code from host drivers into the generic
  function, based on contents of the structure
* Extend pci_host_bridge with additional members when needed without
  having to add arguments to pci_scan_*().
* Move members of struct pci_bus into pci_host_bridge to avoid
  having lots of identical copies.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <helgaas@kernel.org>

Remove the assumption that IORESOURCE_ROM_ENABLE == PCI_ROM_ADDRESS_ENABLE.
PCI_ROM_ADDRESS_ENABLE is the ROM enable bit defined by the PCI spec, so if
we're reading or writing a BAR register value, that's what we should use.
IORESOURCE_ROM_ENABLE is a corresponding bit in struct resource flags.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NGavin Shan <gwshan@linux.vnet.ibm.com>

On DT based systems, the of_dma_configure() API implements DMA
configuration for a given device. On ACPI systems an API equivalent to
of_dma_configure() is missing which implies that it is currently not
possible to set-up DMA operations for devices through the ACPI generic
kernel layer.

This patch fills the gap by introducing acpi_dma_configure/deconfigure()
calls that for now are just wrappers around arch_setup_dma_ops() and
arch_teardown_dma_ops() and also updates ACPI and PCI core code to use
the newly introduced acpi_dma_configure/acpi_dma_deconfigure functions.

Since acpi_dma_configure() is used to configure DMA operations, the
function initializes the dma/coherent_dma masks to sane default values
if the current masks are uninitialized (also to keep the default values
consistent with DT systems) to make sure the device has a complete
default DMA set-up.

The DMA range size passed to arch_setup_dma_ops() is sized according
to the device coherent_dma_mask (starting at address 0x0), mirroring the
DT probing path behaviour when a dma-ranges property is not provided
for the device being probed; this changes the current arch_setup_dma_ops()
call parameters in the ACPI probing case, but since arch_setup_dma_ops()
is a NOP on all architectures but ARM/ARM64 this patch does not change
the current kernel behaviour on them.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> [pci]
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NTomasz Nowicki <tn@semihalf.com>
Tested-by: NHanjun Guo <hanjun.guo@linaro.org>
Tested-by: NTomasz Nowicki <tn@semihalf.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Tomasz Nowicki <tn@semihalf.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Per PCIe spec r3.0, sec 2.3.1.1, the Read Completion Boundary (RCB)
determines the naturally aligned address boundaries on which a Read Request
may be serviced with multiple Completions:

  - For a Root Complex, RCB is 64 bytes or 128 bytes
    This value is reported in the Link Control Register

    Note: Bridges and Endpoints may implement a corresponding command bit
    which may be set by system software to indicate the RCB value for the
    Root Complex, allowing the Bridge/Endpoint to optimize its behavior
    when the Root Complex’s RCB is 128 bytes.

  - For all other system elements, RCB is 128 bytes

Per sec 7.8.7, if a Root Port only supports a 64-byte RCB, the RCB of all
downstream devices must be clear, indicating an RCB of 64 bytes.  If the
Root Port supports a 128-byte RCB, we may optionally set the RCB of
downstream devices so they know they can generate larger Completions.

Some BIOSes supply an _HPX that tells us to set RCB, even though the Root
Port doesn't have RCB set, which may lead to Malformed TLP errors if the
Endpoint generates completions larger than the Root Port can handle.

The IBM x3850 X6 with BIOS version -[A8E120CUS-1.30]- 08/22/2016 supplies
such an _HPX and a Mellanox MT27500 ConnectX-3 device fails to initialize:

  mlx4_core 0000:41:00.0: command 0xfff timed out (go bit not cleared)
  mlx4_core 0000:41:00.0: device is going to be reset
  mlx4_core 0000:41:00.0: Failed to obtain HW semaphore, aborting
  mlx4_core 0000:41:00.0: Fail to reset HCA
  ------------[ cut here ]------------
  kernel BUG at drivers/net/ethernet/mellanox/mlx4/catas.c:193!

After 6cd33649 ("PCI: Add pci_configure_device() during enumeration")
and 7a1562d4 ("PCI: Apply _HPX Link Control settings to all devices
with a link"), we apply _HPX settings to *all* devices, not just those
hot-added after boot.

Before 7a1562d4, we didn't touch the Mellanox RCB, and the device
worked.  After 7a1562d4, we set its RCB to 128, and it failed.

Set the RCB to 128 iff the Root Port supports a 128-byte RCB.  Otherwise,
set RCB to 64 bytes.  This effectively ignores what _HPX tells us about
RCB.

Note that this change only affects _HPX handling.  If we have no _HPX, this
does nothing with RCB.

[bhelgaas: changelog, clear RCB if not set for Root Port]
Fixes: 6cd33649 ("PCI: Add pci_configure_device() during enumeration")
Fixes: 7a1562d4 ("PCI: Apply _HPX Link Control settings to all devices with a link")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=187781Tested-by: NFrank Danapfel <fdanapfe@redhat.com>
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NMyron Stowe <myron.stowe@redhat.com>
CC: stable@vger.kernel.org	# v3.18+

Save the position of the error reporting capability so it doesn't need to
be rediscovered during error handling.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: Lukas Wunner <lukas@wunner.de>

Add Precision Time Measurement (PTM) support (see PCIe r3.1, sec 6.22).

Enable PTM on PTM Root devices and switch ports.  This does not enable PTM
on endpoints.

There currently are no PTM-capable devices on the market, but it is
expected to be supported by the Intel Apollo Lake platform.

[bhelgaas: complete rework]
Signed-off-by: NJonathan Yong <jonathan.yong@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

A user may hot add a switch requiring more than one bus to enumerate.  This
previously required a system reboot if BIOS did not sufficiently pad the
bus resource, which they frequently don't do.

Add a kernel parameter so a user can specify the minimum number of bus
numbers to reserve for a hotplug bridge's subordinate buses so rebooting
won't be necessary.

The default is 1, which is equivalent to previous behavior.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

When a PCI device is removed through sysfs interface, the upstream bridge
(PCIe port) can be runtime suspended if it was the last device on that bus.
Now, if the bridge is in D3 we cannot find devices below the bridge
anymore.  For example following fails to find the removed device again:

  # echo 1 > /sys/bus/pci/devices/0000:00:01.0/0000:01:00.0/remove
  # echo 1 > /sys/bus/pci/devices/0000:00:01.0/rescan

Where 0000:00:01.0 is the bridge device.

In order to be able to rescan devices below the bridge add
pm_runtime_get_sync()/pm_runtime_put() calls to pci_scan_bridge().  This
should keep bridges powered on while their children devices are being
scanned.
Reported-by: NPeter Wu <peter@lekensteyn.nl>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Instead of assigning bus->domain_nr inside pci_bus_assign_domain_nr(),
return the domain and let the caller do the assignment.  Rename
pci_bus_assign_domain_nr() to pci_bus_find_domain_nr() to reflect this.

No functional change intended.

[bhelgaas: changelog]
Signed-off-by: NTomasz Nowicki <tn@semihalf.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>

b84106b4 ("PCI: Disable IO/MEM decoding for devices with non-compliant
BARs") disabled BAR sizing for BARs 0-5 of devices that don't comply with
the PCI spec.  But it didn't do anything for expansion ROM BARs, so we
still try to size them, resulting in warnings like this on Broadwell-EP:

  pci 0000:ff:12.0: BAR 6: failed to assign [mem size 0x00000001 pref]

Move the non-compliant BAR check from __pci_read_base() up to
pci_read_bases() so it applies to the expansion ROM BAR as well as
to BARs 0-5.

Note that direct callers of __pci_read_base(), like sriov_init(), will now
bypass this check.  We haven't had reports of devices with broken SR-IOV
BARs yet.

[bhelgaas: changelog]
Fixes: b84106b4 ("PCI: Disable IO/MEM decoding for devices with non-compliant BARs")
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Andi Kleen <ak@linux.intel.com>