linux-stable.git/drivers/pci/hotplug, branch v5.3.17

ACPI / hotplug / PCI: Allocate resources directly under the non-hotplug bridge

2019-12-17T19:08:01+00:00

commit 77adf9355304f8dcf09054280af5e23fc451ab3d upstream.

Valerio and others reported that commit 84c8b58ed3ad ("ACPI / hotplug /
PCI: Don't scan bridges managed by native hotplug") prevents some recent
LG and HP laptops from booting with endless loop of:

  ACPI Error: No handler or method for GPE 08, disabling event (20190215/evgpe-835)
  ACPI Error: No handler or method for GPE 09, disabling event (20190215/evgpe-835)
  ACPI Error: No handler or method for GPE 0A, disabling event (20190215/evgpe-835)
  ...

What seems to happen is that during boot, after the initial PCI enumeration
when EC is enabled the platform triggers ACPI Notify() to one of the root
ports. The root port itself looks like this:

  pci 0000:00:1b.0: PCI bridge to [bus 02-3a]
  pci 0000:00:1b.0:   bridge window [mem 0xc4000000-0xda0fffff]
  pci 0000:00:1b.0:   bridge window [mem 0x80000000-0xa1ffffff 64bit pref]

The BIOS has configured the root port so that it does not have I/O bridge
window.

Now when the ACPI Notify() is triggered ACPI hotplug handler calls
acpiphp_native_scan_bridge() for each non-hotplug bridge (as this system is
using native PCIe hotplug) and pci_assign_unassigned_bridge_resources() to
allocate resources.

The device connected to the root port is a PCIe switch (Thunderbolt
controller) with two hotplug downstream ports. Because of the hotplug ports
__pci_bus_size_bridges() tries to add "additional I/O" of 256 bytes to each
(DEFAULT_HOTPLUG_IO_SIZE). This gets further aligned to 4k as that's the
minimum I/O window size so each hotplug port gets 4k I/O window and the
same happens for the root port (which is also hotplug port). This means
3 * 4k = 12k I/O window.

Because of this pci_assign_unassigned_bridge_resources() ends up opening a
I/O bridge window for the root port at first available I/O address which
seems to be in range 0x1000 - 0x3fff. Normally this range is used for ACPI
stuff such as GPE bits (below is part of /proc/ioports):

    1800-1803 : ACPI PM1a_EVT_BLK
    1804-1805 : ACPI PM1a_CNT_BLK
    1808-180b : ACPI PM_TMR
    1810-1815 : ACPI CPU throttle
    1850-1850 : ACPI PM2_CNT_BLK
    1854-1857 : pnp 00:05
    1860-187f : ACPI GPE0_BLK

However, when the ACPI Notify() happened this range was not yet reserved
for ACPI/PNP (that happens later) so PCI gets it. It then starts writing to
this range and accidentally stomps over GPE bits among other things causing
the endless stream of messages about missing GPE handler.

This problem does not happen if "pci=hpiosize=0" is passed in the kernel
command line. The reason is that then the kernel does not try to allocate
the additional 256 bytes for each hotplug port.

Fix this by allocating resources directly below the non-hotplug bridges
where a new device may appear as a result of ACPI Notify(). This avoids the
hotplug bridges and prevents opening the additional I/O window.

Fixes: 84c8b58ed3ad ("ACPI / hotplug / PCI: Don't scan bridges managed by native hotplug")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203617
Link: https://lore.kernel.org/r/20191030150545.19885-1-mika.westerberg@linux.intel.com
Reported-by: Valerio Passini 
Signed-off-by: Mika Westerberg 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Rafael J. Wysocki 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

PCI: rpaphp: Avoid a sometimes-uninitialized warning

2019-10-07T17:01:07+00:00

[ Upstream commit 0df3e42167caaf9f8c7b64de3da40a459979afe8 ]

When building with -Wsometimes-uninitialized, clang warns:

drivers/pci/hotplug/rpaphp_core.c:243:14: warning: variable 'fndit' is
used uninitialized whenever 'for' loop exits because its condition is
false [-Wsometimes-uninitialized]
        for (j = 0; j < entries; j++) {
                    ^~~~~~~~~~~
drivers/pci/hotplug/rpaphp_core.c:256:6: note: uninitialized use occurs
here
        if (fndit)
            ^~~~~
drivers/pci/hotplug/rpaphp_core.c:243:14: note: remove the condition if
it is always true
        for (j = 0; j < entries; j++) {
                    ^~~~~~~~~~~
drivers/pci/hotplug/rpaphp_core.c:233:14: note: initialize the variable
'fndit' to silence this warning
        int j, fndit;
                    ^
                     = 0

fndit is only used to gate a sprintf call, which can be moved into the
loop to simplify the code and eliminate the local variable, which will
fix this warning.

Fixes: 2fcf3ae508c2 ("hotplug/drc-info: Add code to search ibm,drc-info property")
Suggested-by: Nick Desaulniers 
Signed-off-by: Nathan Chancellor 
Acked-by: Tyrel Datwyler 
Acked-by: Joel Savitz 
Signed-off-by: Michael Ellerman 
Link: https://github.com/ClangBuiltLinux/linux/issues/504
Link: https://lore.kernel.org/r/20190603221157.58502-1-natechancellor@gmail.com
Signed-off-by: Sasha Levin

Merge tag 'pci-v5.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

2019-05-14T17:30:10+00:00

Pull PCI updates from Bjorn Helgaas:
 "Enumeration changes:

   - Add _HPX Type 3 settings support, which gives firmware more
     influence over device configuration (Alexandru Gagniuc)

   - Support fixed bus numbers from bridge Enhanced Allocation
     capabilities (Subbaraya Sundeep)

   - Add "external-facing" DT property to identify cases where we
     require IOMMU protection against untrusted devices (Jean-Philippe
     Brucker)

   - Enable PCIe services for host controller drivers that use managed
     host bridge alloc (Jean-Philippe Brucker)

   - Log PCIe port service messages with pci_dev, not the pcie_device
     (Frederick Lawler)

   - Convert pciehp from pciehp_debug module parameter to generic
     dynamic debug (Frederick Lawler)

  Peer-to-peer DMA:

   - Add whitelist of Root Complexes that support peer-to-peer DMA
     between Root Ports (Christian König)

  Native controller drivers:

   - Add PCI host bridge DMA ranges for bridges that can't DMA
     everywhere, e.g., iProc (Srinath Mannam)

   - Add Amazon Annapurna Labs PCIe host controller driver (Jonathan
     Chocron)

   - Fix Tegra MSI target allocation so DMA doesn't generate unwanted
     MSIs (Vidya Sagar)

   - Fix of_node reference leaks (Wen Yang)

   - Fix Hyper-V module unload & device removal issues (Dexuan Cui)

   - Cleanup R-Car driver (Marek Vasut)

   - Cleanup Keystone driver (Kishon Vijay Abraham I)

   - Cleanup i.MX6 driver (Andrey Smirnov)

  Significant bug fixes:

   - Reset Lenovo ThinkPad P50 GPU so nouveau works after reboot (Lyude
     Paul)

   - Fix Switchtec firmware update performance issue (Wesley Sheng)

   - Work around Pericom switch link retraining erratum (Stefan Mätje)"

* tag 'pci-v5.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (141 commits)
  MAINTAINERS: Add Karthikeyan Mitran and Hou Zhiqiang for Mobiveil PCI
  PCI: pciehp: Remove pointless MY_NAME definition
  PCI: pciehp: Remove pointless PCIE_MODULE_NAME definition
  PCI: pciehp: Remove unused dbg/err/info/warn() wrappers
  PCI: pciehp: Log messages with pci_dev, not pcie_device
  PCI: pciehp: Replace pciehp_debug module param with dyndbg
  PCI: pciehp: Remove pciehp_debug uses
  PCI/AER: Log messages with pci_dev, not pcie_device
  PCI/DPC: Log messages with pci_dev, not pcie_device
  PCI/PME: Replace dev_printk(KERN_DEBUG) with dev_info()
  PCI/AER: Replace dev_printk(KERN_DEBUG) with dev_info()
  PCI: Replace dev_printk(KERN_DEBUG) with dev_info(), etc
  PCI: Replace printk(KERN_INFO) with pr_info(), etc
  PCI: Use dev_printk() when possible
  PCI: Cleanup setup-bus.c comments and whitespace
  PCI: imx6: Allow asynchronous probing
  PCI: dwc: Save root bus for driver remove hooks
  PCI: dwc: Use devm_pci_alloc_host_bridge() to simplify code
  PCI: dwc: Free MSI in dw_pcie_host_init() error path
  PCI: dwc: Free MSI IRQ page in dw_pcie_free_msi()
  ...

Merge branch 'pci/printk-portdrv'

2019-05-13T23:34:47+00:00

  - Change some desirable KERN_DEBUG messages to KERN_INFO/KERN_ERR
    (Frederick Lawler)

  - Log PCIe port service messages with pci_dev, not the pcie_device
    (Frederick Lawler)

  - Convert pciehp from pciehp_debug module parameter to generic dynamic
    debug (Frederick Lawler)

* pci/printk-portdrv:
  PCI: pciehp: Remove pointless MY_NAME definition
  PCI: pciehp: Remove pointless PCIE_MODULE_NAME definition
  PCI: pciehp: Remove unused dbg/err/info/warn() wrappers
  PCI: pciehp: Log messages with pci_dev, not pcie_device
  PCI: pciehp: Replace pciehp_debug module param with dyndbg
  PCI: pciehp: Remove pciehp_debug uses
  PCI/AER: Log messages with pci_dev, not pcie_device
  PCI/DPC: Log messages with pci_dev, not pcie_device
  PCI/PME: Replace dev_printk(KERN_DEBUG) with dev_info()
  PCI/AER: Replace dev_printk(KERN_DEBUG) with dev_info()

PCI: pciehp: Remove pointless MY_NAME definition

2019-05-09T21:45:21+00:00

MY_NAME is only used once and offers no benefit, so remove it.

Link: https://lore.kernel.org/lkml/20190509141456.223614-11-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Keith Busch 
Reviewed-by: Andy Shevchenko

PCI: pciehp: Remove pointless PCIE_MODULE_NAME definition

2019-05-09T21:45:21+00:00

PCIE_MODULE_NAME is only used once and offers no benefit, so remove it.

Link: https://lore.kernel.org/lkml/20190509141456.223614-10-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Keith Busch 
Reviewed-by: Andy Shevchenko

PCI: pciehp: Remove unused dbg/err/info/warn() wrappers

2019-05-09T21:45:20+00:00

Replace the last uses of dbg() with the equivalent pr_debug(), then remove
unused dbg(), err(), info(), and warn() wrappers.

Link: https://lore.kernel.org/lkml/20190509141456.223614-9-helgaas@kernel.org
Signed-off-by: Frederick Lawler 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Keith Busch 
Reviewed-by: Andy Shevchenko

PCI: pciehp: Log messages with pci_dev, not pcie_device

2019-05-09T21:45:20+00:00

Log messages with pci_dev, not pcie_device.  Factor out common message
prefixes with dev_fmt().

Example output change:

  - pciehp 0000:00:06.0:pcie004: Slot(0) Powering on due to button press
  + pcieport 0000:00:06.0: pciehp: Slot(0) Powering on due to button press

Link: https://lore.kernel.org/lkml/20190509141456.223614-8-helgaas@kernel.org
Signed-off-by: Frederick Lawler 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Keith Busch 
Reviewed-by: Andy Shevchenko

PCI: pciehp: Replace pciehp_debug module param with dyndbg

2019-05-09T21:45:20+00:00

Previously pciehp debug messages were enabled by the pciehp_debug module
parameter, e.g., by booting with this kernel command line option:

  pciehp.pciehp_debug=1

Convert this mechanism to use the generic dynamic debug (dyndbg) feature.
After this commit, pciehp debug messages are enabled by building the kernel
with CONFIG_DYNAMIC_DEBUG=y and booting with this command line option:

  dyndbg="file pciehp* +p"

The dyndbg facility is much more flexible: messages can be enabled at boot-
or run-time based on the file name, function name, line number, message
test, etc.  See Documentation/admin-guide/dynamic-debug-howto.rst for more
details.

Link: https://lore.kernel.org/lkml/20190509141456.223614-7-helgaas@kernel.org
Signed-off-by: Frederick Lawler 
[bhelgaas: commit log, comment, remove pciehp_debug parameter]
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Keith Busch 
Reviewed-by: Andy Shevchenko

PCI: pciehp: Remove pciehp_debug uses

2019-05-09T21:45:19+00:00

We're about to convert pciehp to the dyndbg mechanism, which means we can
eventually remove pciehp_debug.

Replace uses of pciehp_debug with dbg() and ctrl_dbg(), which check
pciehp_debug internally.

Link: https://lore.kernel.org/lkml/20190509141456.223614-6-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Keith Busch 
Reviewed-by: Andy Shevchenko