linux-stable.git/drivers/pci/hotplug, branch linux-4.15.y

PCI: pciehp: Assume NoCompl+ for Thunderbolt ports

2018-02-22T14:40:07+00:00

commit 493fb50e958c1c6deef7feff0b8c3855def78d75 upstream.

Certain Thunderbolt 1 controllers claim to support Command Completed events
(value of 0b in the No Command Completed Support field of the Slot
Capabilities register) but in reality they neither set the Command
Completed bit in the Slot Status register nor signal a Command Completed
interrupt:

  8086:1513  CV82524  [Light Ridge 4C  2010]
  8086:151a  DSL2310  [Eagle Ridge 2C  2011]
  8086:151b  CVL2510  [Light Peak 2C   2010]
  8086:1547  DSL3510  [Cactus Ridge 4C 2012]
  8086:1548  DSL3310  [Cactus Ridge 2C 2012]
  8086:1549  DSL2210  [Port Ridge 1C   2011]

All known newer chips (Redwood Ridge and onwards) set No Command Completed
Support, indicating that they do not support Command Completed events.

The user-visible impact is that after unplugging such a device, 2 seconds
elapse until pciehp is unbound.  That's because on ->remove,
pcie_write_cmd() is called via pcie_disable_notification() and every call
to pcie_write_cmd() takes 2 seconds (1 second for each invocation of
pcie_wait_cmd()):

  [  337.942727] pciehp 0000:0a:00.0:pcie204: Timeout on hotplug command 0x1038 (issued 21176 msec ago)
  [  340.014735] pciehp 0000:0a:00.0:pcie204: Timeout on hotplug command 0x0000 (issued 2072 msec ago)

That by itself has always been unpleasant, but the situation has become
worse with commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during
shutdown"):  Now pciehp is unbound on ->shutdown.  Because Thunderbolt
controllers typically have 4 hotplug ports, every reboot and shutdown is
now delayed by 8 seconds, plus another 2 seconds for every attached
Thunderbolt 1 device.

Thunderbolt hotplug slots are not physical slots that one inserts cards
into, but rather logical hotplug slots implemented in silicon.  Devices
appear beyond those logical slots once a PCI tunnel is established on top
of the Thunderbolt Converged I/O switch.  One would expect commands written
to the Slot Control register to be executed immediately by the silicon, so
for simplicity we always assume NoCompl+ for Thunderbolt ports.

Fixes: cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown")
Tested-by: Mika Westerberg 
Signed-off-by: Lukas Wunner 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Mika Westerberg 
Cc: stable@vger.kernel.org	# v4.12+
Cc: Sinan Kaya 
Cc: Yehezkel Bernat 
Cc: Michael Jamet 
Cc: Andreas Noever 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'pci-v4.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2017-11-15T23:01:28+00:00

Pull PCI updates from Bjorn Helgaas:

  - detach driver before tearing down procfs/sysfs (Alex Williamson)

  - disable PCIe services during shutdown (Sinan Kaya)

  - fix ASPM oops on systems with no Root Ports (Ard Biesheuvel)

  - fix ASPM LTR_L1.2_THRESHOLD programming (Bjorn Helgaas)

  - fix ASPM Common_Mode_Restore_Time computation (Bjorn Helgaas)

  - fix portdrv MSI/MSI-X vector allocation (Dongdong Liu, Bjorn
    Helgaas)

  - report non-fatal AER errors only to the affected endpoint (Gabriele
    Paoloni)

  - distribute bus numbers, MMIO, and I/O space among hotplug bridges to
    allow more devices to be hot-added (Mika Westerberg)

  - fix pciehp races during initialization and surprise link down (Mika
    Westerberg)

  - handle surprise-removed devices in PME handling (Qiang)

  - support resizable BARs for large graphics devices (Christian König)

  - expose SR-IOV offset, stride, and VF device ID via sysfs (Filippo
    Sironi)

  - create SR-IOV virtfn/physfn sysfs links before attaching driver
    (Stuart Hayes)

  - fix SR-IOV "ARI Capable Hierarchy" restore issue (Tony Nguyen)

  - enforce Kconfig IOV/REALLOC dependency (Sascha El-Sharkawy)

  - avoid slot reset if bridge itself is broken (Jan Glauber)

  - clean up pci_reset_function() path (Jan H. Schönherr)

  - make pci_map_rom() fail if the option ROM is invalid (Changbin Du)

  - convert timers to timer_setup() (Kees Cook)

  - move PCI_QUIRKS to PCI bus Kconfig menu (Randy Dunlap)

  - constify pci_dev_type and intel_mid_pci_ops (Bhumika Goyal)

  - remove unnecessary pci_dev, pci_bus, resource, pcibios_set_master()
    declarations (Bjorn Helgaas)

  - fix endpoint framework overflows and BUG()s (Dan Carpenter)

  - fix endpoint framework issues (Kishon Vijay Abraham I)

  - avoid broken Cavium CN8xxx bus reset behavior (David Daney)

  - extend Cavium ACS capability quirks (Vadim Lomovtsev)

  - support Synopsys DesignWare RC in ECAM mode (Ard Biesheuvel)

  - turn off dra7xx clocks cleanly on shutdown (Keerthy)

  - fix Faraday probe error path (Wei Yongjun)

  - support HiSilicon STB SoC PCIe host controller (Jianguo Sun)

  - fix Hyper-V interrupt affinity issue (Dexuan Cui)

  - remove useless ACPI warning for Hyper-V pass-through devices (Vitaly
    Kuznetsov)

  - support multiple MSI on iProc (Sandor Bodo-Merle)

  - support Layerscape LS1012a and LS1046a PCIe host controllers (Hou
    Zhiqiang)

  - fix Layerscape default error response (Minghuan Lian)

  - support MSI on Tango host controller (Marc Gonzalez)

  - support Tegra186 PCIe host controller (Manikanta Maddireddy)

  - use generic accessors on Tegra when possible (Thierry Reding)

  - support V3 Semiconductor PCI host controller (Linus Walleij)

* tag 'pci-v4.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (85 commits)
  PCI/ASPM: Add L1 Substates definitions
  PCI/ASPM: Reformat ASPM register definitions
  PCI/ASPM: Use correct capability pointer to program LTR_L1.2_THRESHOLD
  PCI/ASPM: Account for downstream device's Port Common_Mode_Restore_Time
  PCI: xgene: Rename xgene_pcie_probe_bridge() to xgene_pcie_probe()
  PCI: xilinx: Rename xilinx_pcie_link_is_up() to xilinx_pcie_link_up()
  PCI: altera: Rename altera_pcie_link_is_up() to altera_pcie_link_up()
  PCI: Fix kernel-doc build warning
  PCI: Fail pci_map_rom() if the option ROM is invalid
  PCI: Move pci_map_rom() error path
  PCI: Move PCI_QUIRKS to the PCI bus menu
  alpha/PCI: Make pdev_save_srm_config() static
  PCI: Remove unused declarations
  PCI: Remove redundant pci_dev, pci_bus, resource declarations
  PCI: Remove redundant pcibios_set_master() declarations
  PCI/PME: Handle invalid data when reading Root Status
  PCI: hv: Use effective affinity mask
  PCI: pciehp: Do not clear Presence Detect Changed during initialization
  PCI: pciehp: Fix race condition handling surprise link down
  PCI: Distribute available resources to hotplug-capable bridges
  ...

PCI: pciehp: Do not clear Presence Detect Changed during initialization

2017-11-07T00:49:00+00:00

It is possible that the hotplug event has already happened before the
driver is attached to a PCIe hotplug downstream port. If we just clear the
status we never get the hotplug interrupt and thus the event will be
missed.

To make sure that does not happen, we leave Presence Detect Changed bit
untouched during initialization. Then once the event is unmasked we get an
interrupt and handle the hotplug event properly.

Signed-off-by: Mika Westerberg 
Signed-off-by: Bjorn Helgaas

PCI: pciehp: Fix race condition handling surprise link down

2017-11-07T00:49:00+00:00

A surprise link down may retrain very quickly causing the same slot
generate a link up event before handling the link down event completes.

Since the link is active, the power off work queued from the first link
down will cause a second down event when power is disabled. However, the
link up event sets the slot state to POWERON_STATE before the event to
handle this is enqueued, making the second down event believe it needs to
do something.

This creates constant link up and down event cycle.

To prevent this it is better to handle each event at the time in order it
occurred, so change the driver to use ordered workqueue instead.

A normal device hotplug triggers two events (presense detect and link up)
that are already handled properly in the driver but we currently log an
error if we find an existing device in the slot. Since this is not an error
change the log level to be debug instead to avoid scaring users.

This is based on the original work by Ashok Raj.

Link: https://patchwork.kernel.org/patch/9469023
Suggested-by: Bjorn Helgaas 
Signed-off-by: Mika Westerberg 
Signed-off-by: Bjorn Helgaas

PCI: Add for_each_pci_bridge() helper

2017-11-07T00:48:58+00:00

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: Andy Shevchenko 
[bhelgaas: fold in http://lkml.kernel.org/r/20171013165352.25550-1-andriy.shevchenko@linux.intel.com]
Signed-off-by: Bjorn Helgaas

PCI: shpchp: Convert timers to use timer_setup()

2017-11-07T00:48:57+00:00

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Signed-off-by: Kees Cook 
Signed-off-by: Bjorn Helgaas 
Cc: Ingo Molnar 
Cc: Arvind Yadav 
Cc: Quentin Lambert 
Cc: Aleksandr Bezzubikov 
Cc: "Michael S. Tsirkin" 
Cc: Marcel Apfelbaum

PCI: cpqphp: Convert timers to use timer_setup()

2017-11-07T00:48:57+00:00

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.  This has the result of fixing
pushbutton_helper_thread(), which was truncating the event pointer to 32
bits.

Signed-off-by: Kees Cook 
Signed-off-by: Bjorn Helgaas 
Cc: Ingo Molnar 
Cc: Arvind Yadav 
Cc: Quentin Lambert 
Cc: Aleksandr Bezzubikov 
Cc: "Michael S. Tsirkin" 
Cc: Marcel Apfelbaum

PCI: pciehp: Convert timers to use timer_setup()

2017-11-07T00:48:57+00:00

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly. This fixes what appears to be a bug
in passing the wrong pointer to the timer handler (address of ctrl pointer
instead of ctrl pointer).

Signed-off-by: Kees Cook 
Signed-off-by: Bjorn Helgaas 
Cc: Mika Westerberg 
Cc: Mayurkumar Patel 
Cc: Keith Busch 
Cc: Thomas Gleixner

PCI: ibmphp: Use common error handling code in unconfigure_boot_device()

2017-11-07T00:47:15+00:00

Combine two error paths that emit the same message and return the same
error code.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring 
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman