[ Upstream commit c4eed62a214330908eec11b0dc170d34fa50b412 ]

The secondary bus reset may have link side effects that a hotplug capable
port may incorrectly react to.  Use the slot specific reset for hotplug
ports, fixing the undesirable link down-up handling during error
recovering.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
[bhelgaas: fold in
https://lore.kernel.org/linux-pci/20180926152326.14821-1-keith.busch@intel.com
for issue reported by Stephen Rothwell <sfr@canb.auug.org.au>]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NSinan Kaya <okaya@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit 45144d42f299455911cc29366656c7324a3a7c97 upstream.

There is an arbitrary difference between the system resume and
runtime resume code paths for PCI devices regarding the delay to
apply when switching the devices from D3cold to D0.

Namely, pci_restore_standard_config() used in the runtime resume
code path calls pci_set_power_state() which in turn invokes
__pci_start_power_transition() to power up the device through the
platform firmware and that function applies the transition delay
(as per PCI Express Base Specification Revision 2.0, Section 6.6.1).
However, pci_pm_default_resume_early() used in the system resume
code path calls pci_power_up() which doesn't apply the delay at
all and that causes issues to occur during resume from
suspend-to-idle on some systems where the delay is required.

Since there is no reason for that difference to exist, modify
pci_power_up() to follow pci_set_power_state() more closely and
invoke __pci_start_power_transition() from there to call the
platform firmware to power up the device (in case that's necessary).

Fixes: db288c9c ("PCI / PM: restore the original behavior of pci_set_power_state()")
Reported-by: NDaniel Drake <drake@endlessm.com>
Tested-by: NDaniel Drake <drake@endlessm.com>
Link: https://lore.kernel.org/linux-pm/CAD8Lp44TYxrMgPLkHCqF9hv6smEurMXvmmvmtyFhZ6Q4SE+dig@mail.gmail.com/T/#m21be74af263c6a34f36e0fc5c77c5449d9406925Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit d2182b2d4b71ff0549a07f414d921525fade707b upstream.

In a Resizable BAR Control Register, bits 13:8 control the size of the BAR.
The encoded values of these bits are as follows (see PCIe r5.0, sec
7.8.6.3):

  Value    BAR size
     0     1 MB (2^20 bytes)
     1     2 MB (2^21 bytes)
     2     4 MB (2^22 bytes)
   ...
    43     8 EB (2^63 bytes)

Previously we incorrectly set the BAR size bits for a 1 MB BAR to 0x1f
instead of 0, so devices that support that size, e.g., new megaraid_sas and
mpt3sas adapters, fail to initialize during resume from S3 sleep.

Correctly calculate the BAR size bits for Resizable BAR control registers.

Link: https://lore.kernel.org/r/20190725192552.24295-1-sumit.saxena@broadcom.com
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939
Fixes: d3252ace ("PCI: Restore resized BAR state on resume")
Signed-off-by: NSumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org	# v4.19+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 000dd5316e1c756a1c028f22e01d06a38249dd4d upstream.

PME polling does not take into account that a device that is directly
connected to the host bridge may go into D3cold as well. This leads to a
situation where the PME poll thread reads from a config space of a
device that is in D3cold and gets incorrect information because the
config space is not accessible.

Here is an example from Intel Ice Lake system where two PCIe root ports
are in D3cold (I've instrumented the kernel to log the PMCSR register
contents):

  [   62.971442] pcieport 0000:00:07.1: Check PME status, PMCSR=0xffff
  [   62.971504] pcieport 0000:00:07.0: Check PME status, PMCSR=0xffff

Since 0xffff is interpreted so that PME is pending, the root ports will
be runtime resumed. This repeats over and over again essentially
blocking all runtime power management.

Prevent this from happening by checking whether the device is in D3cold
before its PME status is read.

Fixes: 71a83bd7 ("PCI/PM: add runtime PM support to PCIe port")
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: NLukas Wunner <lukas@wunner.de>
Cc: 3.6+ <stable@vger.kernel.org> # v3.6+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit d5bc73f34cc97c4b4b9202cc93182c2515076edf ]

In most cases, kmalloc() will not be available early in boot when
pci_setup() is called.  Thus, the kstrdup() call that was added to fix the
__initdata bug with the disable_acs_redir parameter usually returns NULL,
so the parameter is discarded and has no effect.

To fix this, store the string that's in initdata until an initcall function
can allocate the memory appropriately.  This way we don't need any
additional static memory.

Fixes: d2fd6e81912a ("PCI: Fix __initdata issue with "pci=disable_acs_redir" parameter")
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

[ Upstream commit 85b0cae89d5266e6a7abb2e83c6f716326fc494c ]

Gigabyte X299 DESIGNARE EX motherboard has one PCIe root port that is
connected to an Alpine Ridge Thunderbolt controller.  This port has slot
implemented bit set in the config space but other than that it is not
hotplug capable in the sense we are expecting in Linux (it has
dev->is_hotplug_bridge set to 0):

  00:1c.4 PCI bridge: Intel Corporation 200 Series PCH PCI Express Root Port #5
    Bus: primary=00, secondary=05, subordinate=46, sec-latency=0
    Memory behind bridge: 78000000-8fffffff [size=384M]
    Prefetchable memory behind bridge: 00003800f8000000-00003800ffffffff [size=128M]
    ...
    Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00
    ...
      SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise-
	      Slot #8, PowerLimit 25.000W; Interlock- NoCompl+
      SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg-
	      Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock-
      SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet- Interlock-
	      Changed: MRL- PresDet+ LinkState+

This system is using ACPI based hotplug to notify the OS that it needs to
rescan the PCI bus (ACPI hotplug).

If there is nothing connected in any of the Thunderbolt ports the root port
will not have any runtime PM active children and is thus automatically
runtime suspended pretty soon after boot by PCI PM core.  Now, when a
device is connected the BIOS SMI handler responsible for enumerating newly
added devices is not able to find anything because the port is in D3.

Prevent this from happening by blacklisting PCI power management of this
particular Gigabyte system.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=202031Reported-by: NKedar A Dongre <kedar.a.dongre@intel.com>
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

commit d2fd6e81912a665993b24dcdc1c1384a42a54f7e upstream.

The disable_acs_redir parameter stores a pointer to the string passed to
pci_setup().  However, the string passed to PCI setup is actually a
temporary copy allocated in static __initdata memory.  After init, once the
memory is freed, it is no longer valid to reference this pointer.

This bug was noticed in v5.0-rc1 after a change in commit c5eb1190074c
("PCI / PM: Allow runtime PM without callback functions") caused
pci_disable_acs_redir() to be called during shutdown which manifested
as an unable to handle kernel paging request at:

  RIP: 0010:pci_enable_acs+0x3f/0x1e0
  Call Trace:
     pci_restore_state.part.44+0x159/0x3c0
     pci_restore_standard_config+0x33/0x40
     pci_pm_runtime_resume+0x2b/0xd0
     ? pci_restore_standard_config+0x40/0x40
     __rpm_callback+0xbc/0x1b0
     rpm_callback+0x1f/0x70
     ? pci_restore_standard_config+0x40/0x40
      rpm_resume+0x4f9/0x710
     ? pci_conf1_read+0xb6/0xf0
     ? pci_conf1_write+0xb2/0xe0
     __pm_runtime_resume+0x47/0x70
     pci_device_shutdown+0x1e/0x60
     device_shutdown+0x14a/0x1f0
     kernel_restart+0xe/0x50
     __do_sys_reboot+0x1ee/0x210
     ? __fput+0x144/0x1d0
     do_writev+0x5e/0xf0
     ? do_writev+0x5e/0xf0
     do_syscall_64+0x48/0xf0
     entry_SYSCALL_64_after_hwframe+0x44/0xa9

It was also likely possible to trigger this bug when hotplugging PCI
devices.

To fix this, instead of storing a pointer, we use kstrdup() to copy the
disable_acs_redir_param to its own buffer which will never be freed.

Fixes: aaca43fd ("PCI: Add "pci=disable_acs_redir=" parameter for peer-to-peer support")
Tested-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f1f90e254e46e0a14220e4090041f68256fbe297 upstream.

The macros PCI_EXP_LNKCAP_SLS_*GB are values, not bit masks.  We must mask
the register and compare it against them.

This fixes errors like this:

  amdgpu: [powerplay] failed to send message 261 ret is 0

when a PCIe-v3 card is plugged into a PCIe-v1 slot, because the slot is
being incorrectly reported as PCIe-v3 capable.

6cf57be0, which appeared in v4.17, added pcie_get_speed_cap() with the
incorrect test of PCI_EXP_LNKCAP_SLS as a bitmask.  5d9a6330, which
appeared in v4.19, changed amdgpu to use pcie_get_speed_cap(), so the
amdgpu bug reports below are regressions in v4.19.

Fixes: 6cf57be0 ("PCI: Add pcie_get_speed_cap() to find max supported link speed")
Fixes: 5d9a6330 ("drm/amdgpu: use pcie functions for link width and speed")
Link: https://bugs.freedesktop.org/show_bug.cgi?id=108704
Link: https://bugs.freedesktop.org/show_bug.cgi?id=108778Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
[bhelgaas: update comment, remove use of PCI_EXP_LNKCAP_SLS_8_0GB and
PCI_EXP_LNKCAP_SLS_16_0GB since those should be covered by PCI_EXP_LNKCAP2,
remove test of PCI_EXP_LNKCAP for zero, since that register is required]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org	# v4.17+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On 38+ Intel-based ASUS products, the NVIDIA GPU becomes unusable after S3
suspend/resume.  The affected products include multiple generations of
NVIDIA GPUs and Intel SoCs.  After resume, nouveau logs many errors such
as:

  fifo: fault 00 [READ] at 0000005555555000 engine 00 [GR] client 04
        [HUB/FE] reason 4a [] on channel -1 [007fa91000 unknown]
  DRM: failed to idle channel 0 [DRM]

Similarly, the NVIDIA proprietary driver also fails after resume (black
screen, 100% CPU usage in Xorg process).  We shipped a sample to NVIDIA for
diagnosis, and their response indicated that it's a problem with the parent
PCI bridge (on the Intel SoC), not the GPU.

Runtime suspend/resume works fine, only S3 suspend is affected.

We found a workaround: on resume, rewrite the Intel PCI bridge
'Prefetchable Base Upper 32 Bits' register (PCI_PREF_BASE_UPPER32).  In the
cases that I checked, this register has value 0 and we just have to rewrite
that value.

Linux already saves and restores PCI config space during suspend/resume,
but this register was being skipped because upon resume, it already has
value 0 (the correct, pre-suspend value).

Intel appear to have previously acknowledged this behaviour and the
requirement to rewrite this register:
https://bugzilla.kernel.org/show_bug.cgi?id=116851#c23

Based on that, rewrite the prefetch register values even when that appears
unnecessary.

We have confirmed this solution on all the affected models we have in-hands
(X542UQ, UX533FD, X530UN, V272UN).

Additionally, this solves an issue where r8169 MSI-X interrupts were broken
after S3 suspend/resume on ASUS X441UAR.  This issue was recently worked
around in commit 7bb05b85 ("r8169: don't use MSI-X on RTL8106e").  It
also fixes the same issue on RTL6186evl/8111evl on an Aimfor-tech laptop
that we had not yet patched.  I suspect it will also fix the issue that was
worked around in commit 7c53a722 ("r8169: don't use MSI-X on
RTL8168g").

Thomas Martitz reports that this change also solves an issue where the AMD
Radeon Polaris 10 GPU on the HP Zbook 14u G5 is unresponsive after S3
suspend/resume.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=201069Signed-off-by: NDaniel Drake <drake@endlessm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-By: NPeter Wu <peter@lekensteyn.nl>
CC: stable@vger.kernel.org

Calling into the new API to reset the secondary bus results in a deadlock.
This occurs because the device/bus is already locked at probe time.
Reverting back to the old behavior while the API is improved.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=200985
Fixes: c6a44ba9 ("PCI: Rename pci_try_reset_bus() to pci_reset_bus()")
Fixes: 409888e0 ("IB/hfi1: Use pci_try_reset_bus() for initiating PCI Secondary Bus Reset")
Signed-off-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Cc: Sinan Kaya <okaya@codeaurora.org>

The pci_reset_bus() function calls pci_probe_reset_slot() to determine
whether to call the slot or bus reset.  The check has faulty logic in that
it does not account for pci_probe_reset_slot() being able to return an
errno.  Fix by only calling the slot reset when the function returns 0.

Fixes: 811c5cb3 ("PCI: Unify try slot and bus reset API")
Signed-off-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NMichael J. Ruhl <michael.j.ruhl@intel.com>
Cc: Sinan Kaya <okaya@codeaurora.org>

When both ends of a PCIe Link are capable of a higher bandwidth than is
currently in use, the Link is said to be "downtrained".  A downtrained Link
may indicate hardware or configuration problems in the system, but it's
hard to identify such Links from userspace.

Refactor pcie_print_link_status() so it continues to always print PCIe
bandwidth information, as several NIC drivers desire.

Add a new internal __pcie_print_link_status() to emit a message only when a
device's bandwidth is constrained by the fabric and call it from the PCI
core for all devices, which identifies all downtrained Links.  It also
emits messages for a few cases that are technically not downtrained, such
as a x4 device in an open-ended x1 slot.
Signed-off-by: NAlexandru Gagniuc <mr.nuke.me@gmail.com>
[bhelgaas: changelog, move __pcie_print_link_status() declaration to
drivers/pci/, rename pcie_check_upstream_link() to
pcie_report_downtraining()]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Intel Sunrise Point (SPT) PCH hardware has an implementation of the ACS
bits that does not comply with the PCIe standard.  To deal with this we
need device-specific quirks to disable ACS redirection.

Add a new pci_dev_specific_disable_acs_redir() quirk and a new
.disable_acs_redir() function pointer for use by non-compliant devices.  No
functional change intended.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
[bhelgaas: split to separate patch, move
pci_dev_specific_disable_acs_redir() declarations to drivers/pci/pci.h]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>

To support peer-to-peer traffic on a segment of the PCI hierarchy, we must
disable the ACS redirect bits for select PCI bridges.  The bridges must be
selected before the devices are discovered by the kernel and the IOMMU
groups created.  Therefore, add a kernel command line parameter to specify
devices which must have their ACS bits disabled.

The new parameter takes a list of devices separated by a semicolon.  Each
device specified will have its ACS redirect bits disabled.  This is
similar to the existing 'resource_alignment' parameter.

The ACS Request P2P Request Redirect, P2P Completion Redirect and P2P
Egress Control bits are disabled, which is sufficient to always allow
passing P2P traffic uninterrupted.  The bits are set after the kernel
(optionally) enables the ACS bits itself.  It is also done regardless of
whether the kernel or platform firmware sets the bits.

If the user tries to disable the ACS redirect for a device without the ACS
capability, print a warning to dmesg.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
[bhelgaas: reorder to add the generic code first and move the
device-specific quirk to subsequent patches]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NChristian König <christian.koenig@amd.com>

When specifying PCI devices on the kernel command line using a
bus/device/function address, bus numbers can change when adding or
replacing a device, changing motherboard firmware, or applying kernel
parameters like "pci=assign-buses".  When bus numbers change, it's likely
the command line tweak will be applied to the wrong device.

Therefore, it is useful to be able to specify devices with a base bus
number and the path of devfns needed to get to it, similar to the "device
scope" structure in the Intel VT-d spec, Section 8.3.1.

Thus, we add an option to specify devices in the following format:

  [<domain>:]<bus>:<device>.<func>[/<device>.<func>]*

The path can be any segment within the PCI hierarchy of any length and
determined through the use of 'lspci -t'.  When specified this way, it is
less likely that a renumbered bus will result in a valid device
specification and the tweak won't be applied to the wrong device.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
[bhelgaas: use "device" instead of "slot" in documentation since that's the
usual language in the PCI specs]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NChristian König <christian.koenig@amd.com>

Separate out the code to match a PCI device with a string (typically
originating from a kernel parameter) from the
pci_specified_resource_alignment() function into its own helper function.

While we are at it, this change fixes the kernel style of the function
(fixing a number of long lines and extra parentheses).

Additionally, make the analogous change to the kernel parameter
documentation: Separate the description of how to specify a PCI device
into its own section at the head of the "pci=" parameter.

This patch should have no functional alterations.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
[bhelgaas: use "device" instead of "slot" in documentation since that's the
usual language in the PCI specs]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NChristian König <christian.koenig@amd.com>

pcie_flr() suggests pcie_has_flr() to ensure that PCIe FLR support is
present prior to calling.  pcie_flr() is exported while pcie_has_flr()
is not.  Resolve this.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Several PCI core files include pci-aspm.h even though they don't need
anything provided by that file.  Remove the unnecessary includes of it.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NSinan Kaya <okaya@kernel.org>

Thunderbolt controllers can be runtime suspended to D3cold to save ~1.5W.
This requires that runtime D3 is allowed on its PCIe ports, so whitelist
them.

The 2015 BIOS cutoff that we've instituted for runtime D3 on PCIe ports
is unnecessary on Thunderbolt because we know that even the oldest
controller, Light Ridge (2010), is able to suspend its ports to D3 just
fine -- specifically including its hotplug ports.  And the power saving
should be afforded to machines even if their BIOS predates 2015.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andreas Noever <andreas.noever@gmail.com>

Previously we blacklisted PCIe hotplug ports for runtime D3 because:

(a) Ports handled by the firmware must not be transitioned to D3 by the
    OS behind the firmware's back:
    https://bugzilla.kernel.org/show_bug.cgi?id=53811

(b) Ports handled natively by the OS lacked runtime D3 support in the
    pciehp driver.

We've just rectified the latter, so allow users to manually enable and
test it by passing pcie_port_pm=force on the command line.  Vendors are
thus put in a position to validate hotplug ports for runtime D3 and
perhaps we can someday enable it by default, but with a BIOS cutoff date.

Ashok Raj tested runtime D3 on hotplug ports of a SkyLake Xeon-SP in
2017 and encountered Hardware Error NMIs, so this feature clearly cannot
be enabled for everyone yet:
https://lkml.kernel.org/r/20170503180426.GA4058@otc-nc-03

While at it, remove an erroneous code comment I added with 97a90aee
("PCI: Consolidate conditions to allow runtime PM on PCIe ports") which
claims that parents of a hotplug port must stay awake lest interrupts
cannot be delivered.  That has turned out to be wrong at least for
Thunderbolt hotplug ports.
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>

Now that the old implementation of pci_reset_bus() is gone, replace
pci_try_reset_bus() with pci_reset_bus().

Compared to the old implementation, new code will fail immmediately with
-EAGAIN if object lock cannot be obtained.
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

pci_reset_bus() and pci_reset_slot() functions are not being used by any
code.  Remove them from the kernel in favor of pci_try_reset_bus() and
pci_try_reset_slot() functions.
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Drivers are expected to call pci_try_reset_slot() or pci_try_reset_bus() by
querying if a system supports hotplug or not.  A survey showed that most
drivers don't do this and we are leaking hotplug capability to the user.

Hide pci_try_slot_reset() from drivers and embed into pci_try_bus_reset().
Change pci_try_reset_bus() parameter from struct pci_bus to struct pci_dev.
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Rename pci_reset_bridge_secondary_bus() to pci_bridge_secondary_bus_reset()
and move the declaration from linux/pci.h to drivers/pci.h to be used
internally in PCI directory only.
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Commit 01fd61c0 ("PCI: Add a return type for
pci_reset_bridge_secondary_bus()") added a return value to the function to
return if a device is accessible following a reset.  Callers are not
checking the value.

Pass error code up high in the stack if device is not accessible.

Fixes: 01fd61c0 ("PCI: Add a return type for pci_reset_bridge_secondary_bus()")
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

When testing the R-Car PCIe driver on the Condor board, if the PCIe PHY
driver was left disabled, the kernel crashed with this BUG:

  kernel BUG at lib/ioremap.c:72!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 39 Comm: kworker/0:1 Not tainted 4.17.0-dirty #1092
  Hardware name: Renesas Condor board based on r8a77980 (DT)
  Workqueue: events deferred_probe_work_func
  pstate: 80000005 (Nzcv daif -PAN -UAO)
  pc : ioremap_page_range+0x370/0x3c8
  lr : ioremap_page_range+0x40/0x3c8
  sp : ffff000008da39e0
  x29: ffff000008da39e0 x28: 00e8000000000f07
  x27: ffff7dfffee00000 x26: 0140000000000000
  x25: ffff7dfffef00000 x24: 00000000000fe100
  x23: ffff80007b906000 x22: ffff000008ab8000
  x21: ffff000008bb1d58 x20: ffff7dfffef00000
  x19: ffff800009c30fb8 x18: 0000000000000001
  x17: 00000000000152d0 x16: 00000000014012d0
  x15: 0000000000000000 x14: 0720072007200720
  x13: 0720072007200720 x12: 0720072007200720
  x11: 0720072007300730 x10: 00000000000000ae
  x9 : 0000000000000000 x8 : ffff7dffff000000
  x7 : 0000000000000000 x6 : 0000000000000100
  x5 : 0000000000000000 x4 : 000000007b906000
  x3 : ffff80007c61a880 x2 : ffff7dfffeefffff
  x1 : 0000000040000000 x0 : 00e80000fe100f07
  Process kworker/0:1 (pid: 39, stack limit = 0x        (ptrval))
  Call trace:
   ioremap_page_range+0x370/0x3c8
   pci_remap_iospace+0x7c/0xac
   pci_parse_request_of_pci_ranges+0x13c/0x190
   rcar_pcie_probe+0x4c/0xb04
   platform_drv_probe+0x50/0xbc
   driver_probe_device+0x21c/0x308
   __device_attach_driver+0x98/0xc8
   bus_for_each_drv+0x54/0x94
   __device_attach+0xc4/0x12c
   device_initial_probe+0x10/0x18
   bus_probe_device+0x90/0x98
   deferred_probe_work_func+0xb0/0x150
   process_one_work+0x12c/0x29c
   worker_thread+0x200/0x3fc
   kthread+0x108/0x134
   ret_from_fork+0x10/0x18
  Code: f9004ba2 54000080 aa0003fb 17ffff48 (d4210000)

It turned out that pci_remap_iospace() wasn't undone when the driver's
probe failed, and since devm_phy_optional_get() returned -EPROBE_DEFER,
the probe was retried, finally causing the BUG due to trying to remap
already remapped pages.

Introduce the devm_pci_remap_iospace() managed API and replace the
pci_remap_iospace() call with it to fix the bug.

Fixes: dbf9826d ("PCI: generic: Convert to DT resource parsing API")
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
[lorenzo.pieralisi@arm.com: split commit/updated the commit log]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where
we are expecting to fall through.

Warning level 2 was used: -Wimplicit-fallthrough=2
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

So drivers can use them.  This can be used to replace
duplicate code in the drm subsystem.
Acked-by: NChristian König <christian.koenig@amd.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Seeing there's been some confusion about the use of pci_add_dma_alias(),
expand the comment to describe why it must be called early and how
early it must be called.

Also, expand on the purpose of this function and common reasons it would
be used.

[The comment was reworded to some extent by Alex Williamson]
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Doug Meyer <dmeyer@gigaio.com>

Move early dump functionality into common code so that it is available for
all architectures.  No need to carry arch-specific reads around as the read
hooks are already initialized by the time pci_setup_device() is getting
called during scan.
Tested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NSinan Kaya <okaya@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>

Cleanup PCI_REBAR_CTRL_BAR_SHIFT handling.  That was hard coded instead of
properly defined in the header for some reason.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Resize BARs after resume to the expected size again.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199959
Fixes: d6895ad3 ("drm/amdgpu: resize VRAM BAR for CPU access v6")
Fixes: 276b738d ("PCI: Add resizable BAR infrastructure")
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org      # v4.15+

In some cases pcie_get_minimum_link() returned misleading information
because it found the slowest link and the narrowest link without
considering the total bandwidth of the link.

For example, consider a path with these two links:

  - 16.0 GT/s  x1 link  (16.0 * 10^9 * 128 / 130) *  1 / 8 = 1969 MB/s
  -  2.5 GT/s x16 link  ( 2.5 * 10^9 *   8 /  10) * 16 / 8 = 4000 MB/s

The available bandwidth of the path is limited by the 16 GT/s link to about
1969 MB/s, but pcie_get_minimum_link() returned 2.5 GT/s x1, which
corresponds to only 250 MB/s.

Callers should use pcie_print_link_status() instead, or
pcie_bandwidth_available() if they need more detailed information.

Remove pcie_get_minimum_link() since there are no callers left.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Two comments in pci_target_state() are outdated, as the function
doesn't set the target power state for the device any more, only
finds one for it, so fix them accordingly.
Reported-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

Clients such as hotplug and Downstream Port Containment (DPC) both need to
wait until a link becomes active or inactive.

Add a generic pcie_wait_link_active() interface and use it instead of
duplicating the code.
Signed-off-by: NOza Pawandeep <poza@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NKeith Busch <keith.busch@intel.com>

The only user of pci_get_new_domain_nr() is of_pci_bus_find_domain_nr().
Since they are defined in the same file, pci_get_new_domain_nr() can be
made static, which also simplifies preprocessor conditionals.

No functional change intended.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Adds a "pci=noats" boot parameter.  When supplied, all ATS related
functions fail immediately and the IOMMU is configured to not use
device-IOTLB.

Any function that checks for ATS capabilities directly against the devices
should also check this flag.  Currently, such functions exist only in IOMMU
drivers, and they are covered by this patch.

The motivation behind this patch is the existence of malicious devices.
Lots of research has been done about how to use the IOMMU as protection
from such devices.  When ATS is supported, any I/O device can access any
physical address by faking device-IOTLB entries.  Adding the ability to
ignore these entries lets sysadmins enhance system security.
Signed-off-by: NGil Kupfer <gilkup@cs.technion.ac.il>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NJoerg Roedel <jroedel@suse.de>

Commit 0847684c (PCI / PM: Simplify device wakeup settings code)
went too far and dropped the device_may_wakeup() check from
pci_enable_wake() which causes wakeup to be enabled during system
suspend, hibernation or shutdown for some PCI devices that are not
allowed by user space to wake up the system from sleep (or power off).

As a result of this, excessive power is drawn by some of the affected
systems while in sleep states or off.

Restore the device_may_wakeup() check in pci_enable_wake(), but make
sure that the PCI bus type's runtime suspend callback will not call
device_may_wakeup() which is about system wakeup from sleep and not
about device wakeup from runtime suspend.

Fixes: 0847684c (PCI / PM: Simplify device wakeup settings code)
Reported-by: NJoseph Salisbury <joseph.salisbury@canonical.com>
Cc: 4.13+ <stable@vger.kernel.org> # 4.13+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>

USB controller ASM1042 stops working after commit de3ef1eb (PM /
core: Drop run_wake flag from struct dev_pm_info).

The device in question is not power managed by platform firmware,
furthermore, it only supports PME# from D3cold:
Capabilities: [78] Power Management version 3
       Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0-,D1-,D2-,D3hot-,D3cold+)
       Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-

Before commit de3ef1eb, the device never gets runtime suspended.
After that commit, the device gets runtime suspended to D3hot, which can
not generate any PME#.

usb_hcd_pci_probe() unconditionally calls device_wakeup_enable(), hence
device_can_wakeup() in pci_dev_run_wake() always returns true.

So pci_dev_run_wake() needs to check PME wakeup capability as its first
condition.

In addition, change wakeup flag passed to pci_target_state() from false
to true, because we want to find the deepest state different from D3cold
that the device can still generate PME#. In this case, it's D0 for the
device in question.

Fixes: de3ef1eb (PM / core: Drop run_wake flag from struct dev_pm_info)
Signed-off-by: NKai-Heng Feng <kai.heng.feng@canonical.com>
Cc: 4.13+ <stable@vger.kernel.org> # 4.13+
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently the pcie_print_link_status() will print PCIe bandwidth and link
width information but does not mention it is pertaining to the PCIe.  Since
this and related functions are used exclusively by networking drivers today
users may get confused into thinking that it's the NIC bandwidth that is
being talked about.  Insert a "PCIe" into the messages.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>