commit 92912b1751 upstream.
Writes to a Downstream Port's Slot Control register are PCIe hotplug
"commands." If the Port supports Command Completed events, software must
wait for a command to complete before writing to Slot Control again.
pcie_do_write_cmd() sets ctrl->cmd_busy when it writes to Slot Control. If
software notification is enabled, i.e., PCI_EXP_SLTCTL_HPIE and
PCI_EXP_SLTCTL_CCIE are set, ctrl->cmd_busy is cleared by pciehp_isr().
But when software notification is disabled, as it is when pcie_init()
powers off an empty slot, pcie_wait_cmd() uses pcie_poll_cmd() to poll for
command completion, and it neglects to clear ctrl->cmd_busy, which leads to
spurious timeouts:
pcieport 0000:00:03.0: pciehp: Timeout on hotplug command 0x01c0 (issued 2264 msec ago)
pcieport 0000:00:03.0: pciehp: Timeout on hotplug command 0x05c0 (issued 2288 msec ago)
Clear ctrl->cmd_busy in pcie_poll_cmd() when it detects a Command Completed
event (PCI_EXP_SLTSTA_CC).
[bhelgaas: commit log]
Fixes: a5dd4b4b05 ("PCI: pciehp: Wait for hotplug command completion where necessary")
Link: https://lore.kernel.org/r/20211111054258.7309-1-zhangliguang@linux.alibaba.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215143
Link: https://lore.kernel.org/r/20211126173309.GA12255@wunner.de
Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 23584c1ed3 upstream.
The Power Fault Detected bit in the Slot Status register differs from
all other hotplug events in that it is sticky: It can only be cleared
after turning off slot power. Per PCIe r5.0, sec. 6.7.1.8:
If a power controller detects a main power fault on the hot-plug slot,
it must automatically set its internal main power fault latch [...].
The main power fault latch is cleared when software turns off power to
the hot-plug slot.
The stickiness used to cause interrupt storms and infinite loops which
were fixed in 2009 by commits 5651c48cfa ("PCI pciehp: fix power fault
interrupt storm problem") and 99f0169c17 ("PCI: pciehp: enable
software notification on empty slots").
Unfortunately in 2020 the infinite loop issue was inadvertently
reintroduced by commit 8edf5332c3 ("PCI: pciehp: Fix MSI interrupt
race"): The hardirq handler pciehp_isr() clears the PFD bit until
pciehp's power_fault_detected flag is set. That happens in the IRQ
thread pciehp_ist(), which never learns of the event because the hardirq
handler is stuck in an infinite loop. Fix by setting the
power_fault_detected flag already in the hardirq handler.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214989
Link: https://lore.kernel.org/linux-pci/DM8PR11MB5702255A6A92F735D90A4446868B9@DM8PR11MB5702.namprd11.prod.outlook.com
Fixes: 8edf5332c3 ("PCI: pciehp: Fix MSI interrupt race")
Link: https://lore.kernel.org/r/66eaeef31d4997ceea357ad93259f290ededecfd.1637187226.git.lukas@wunner.de
Reported-by: Joseph Bao <joseph.bao@intel.com>
Tested-by: Joseph Bao <joseph.bao@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v4.19+
Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 085a9f4343 upstream.
Use down_read_nested() and down_write_nested() when taking the
ctrl->reset_lock rw-sem, passing the number of PCIe hotplug controllers in
the path to the PCI root bus as lock subclass parameter.
This fixes the following false-positive lockdep report when unplugging a
Lenovo X1C8 from a Lenovo 2nd gen TB3 dock:
pcieport 0000:06:01.0: pciehp: Slot(1): Link Down
pcieport 0000:06:01.0: pciehp: Slot(1): Card not present
============================================
WARNING: possible recursive locking detected
5.16.0-rc2+ #621 Not tainted
--------------------------------------------
irq/124-pciehp/86 is trying to acquire lock:
ffff8e5ac4299ef8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_check_presence+0x23/0x80
but task is already holding lock:
ffff8e5ac4298af8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_ist+0xf3/0x180
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&ctrl->reset_lock);
lock(&ctrl->reset_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by irq/124-pciehp/86:
#0: ffff8e5ac4298af8 (&ctrl->reset_lock){.+.+}-{3:3}, at: pciehp_ist+0xf3/0x180
#1: ffffffffa3b024e8 (pci_rescan_remove_lock){+.+.}-{3:3}, at: pciehp_unconfigure_device+0x31/0x110
#2: ffff8e5ac1ee2248 (&dev->mutex){....}-{3:3}, at: device_release_driver+0x1c/0x40
stack backtrace:
CPU: 4 PID: 86 Comm: irq/124-pciehp Not tainted 5.16.0-rc2+ #621
Hardware name: LENOVO 20U90SIT19/20U90SIT19, BIOS N2WET30W (1.20 ) 08/26/2021
Call Trace:
<TASK>
dump_stack_lvl+0x59/0x73
__lock_acquire.cold+0xc5/0x2c6
lock_acquire+0xb5/0x2b0
down_read+0x3e/0x50
pciehp_check_presence+0x23/0x80
pciehp_runtime_resume+0x5c/0xa0
device_for_each_child+0x45/0x70
pcie_port_device_runtime_resume+0x20/0x30
pci_pm_runtime_resume+0xa7/0xc0
__rpm_callback+0x41/0x110
rpm_callback+0x59/0x70
rpm_resume+0x512/0x7b0
__pm_runtime_resume+0x4a/0x90
__device_release_driver+0x28/0x240
device_release_driver+0x26/0x40
pci_stop_bus_device+0x68/0x90
pci_stop_bus_device+0x2c/0x90
pci_stop_and_remove_bus_device+0xe/0x20
pciehp_unconfigure_device+0x6c/0x110
pciehp_disable_slot+0x5b/0xe0
pciehp_handle_presence_or_link_change+0xc3/0x2f0
pciehp_ist+0x179/0x180
This lockdep warning is triggered because with Thunderbolt, hotplug ports
are nested. When removing multiple devices in a daisy-chain, each hotplug
port's reset_lock may be acquired recursively. It's never the same lock, so
the lockdep splat is a false positive.
Because locks at the same hierarchy level are never acquired recursively, a
per-level lockdep class is sufficient to fix the lockdep warning.
The choice to use one lockdep subclass per pcie-hotplug controller in the
path to the root-bus was made to conserve class keys because their number
is limited and the complexity grows quadratically with number of keys
according to Documentation/locking/lockdep-design.rst.
Link: https://lore.kernel.org/linux-pci/20190402021933.GA2966@mit.edu/
Link: https://lore.kernel.org/linux-pci/de684a28-9038-8fc6-27ca-3f6f2f6400d7@redhat.com/
Link: https://lore.kernel.org/r/20211217141709.379663-1-hdegoede@redhat.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208855
Reported-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit 2a671f77ee ("s390/pci: fix use after free of zpci_dev")
the reference count of a zpci_dev is incremented between
pcibios_add_device() and pcibios_release_device() which was supposed to
prevent the zpci_dev from being freed while the common PCI code has
access to it. It was missed however that the handling of zPCI
availability events assumed that once zpci_zdev_put() was called no
later availability event would still see the device. With the previously
mentioned commit however this assumption no longer holds and we must
make sure that we only drop the initial long-lived reference the zPCI
subsystem holds exactly once.
Do so by introducing a zpci_device_reserved() function that handles when
a device is reserved. Here we make sure the zpci_dev will not be
considered for further events by removing it from the zpci_list.
This also means that the device actually stays in the
ZPCI_FN_STATE_RESERVED state between the time we know it has been
reserved and the final reference going away. We thus need to consider it
a real state instead of just a conceptual state after the removal. The
final cleanup of PCI resources, removal from zbus, and destruction of
the IOMMU stays in zpci_release_device() to make sure holders of the
reference do see valid data until the release.
Fixes: 2a671f77ee ("s390/pci: fix use after free of zpci_dev")
Cc: stable@vger.kernel.org
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
- Cache PCIe Device Capabilities register (Amey Narkhede)
- Add pcie_reset_flr() with 'probe' argument (Amey Narkhede)
- Add pdev->reset_methods[] array to track reset method ordering (Amey
Narkhede)
- Remove reset_fn field from pci_dev (Amey Narkhede)
- Add sysfs interface to query and set device reset mechanism (Amey
Narkhede)
- Add pci_set_acpi_fwnode() to set ACPI_COMPANION (Shanker Donthineni)
- Use acpi_pci_power_manageable() instead of duplicating logic (Shanker
Donthineni)
- Set ACPI fwnode early and at the same time with OF (Shanker Donthineni)
- Add support for ACPI _RST reset method (Shanker Donthineni)
- Change reset function 'probe' argument to bool (Amey Narkhede)
* pci/reset:
PCI: Change the type of probe argument in reset functions
PCI: Add support for ACPI _RST reset method
PCI: Setup ACPI fwnode early and at the same time with OF
PCI: Use acpi_pci_power_manageable()
PCI: Add pci_set_acpi_fwnode() to set ACPI_COMPANION
PCI: Allow userspace to query and set device reset mechanism
PCI: Remove reset_fn field from pci_dev
PCI: Add array to track reset method ordering
PCI: Add pcie_reset_flr() with 'probe' argument
PCI: Cache PCIe Device Capabilities register
ebda_rsrc_controller() calls iounmap(io_mem) on the error path. Its caller,
ibmphp_access_ebda(), also calls iounmap(io_mem) on good and error paths.
Remove the iounmap(io_mem) invocation from ebda_rsrc_controller().
[bhelgaas: remove item from TODO]
Link: https://lore.kernel.org/r/20210818165751.591185-1-os.vaslot@gmail.com
Signed-off-by: Vishal Aslot <os.vaslot@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Change the type of probe argument in functions which implement reset
methods from int to bool to make the context and intent clear.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20210817180500.1253-10-ameynarkhede03@gmail.com
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
cpci_debug is declared as a global variable in cpci_hotplug_core.c and used
in cpci_hotplug_pci.c via an "extern". Add an extern declaration in the
header file.
Resolves the following sparse warning:
drivers/pci/hotplug/cpci_hotplug_core.c:47:5: warning: symbol 'cpci_debug' was not declared. Should it be static?
Link: https://lore.kernel.org/r/20210701184306.1492003-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Downstream Port Containment (PCIe r5.0, sec. 6.2.10) disables the link upon
an error and attempts to re-enable it when instructed by the DPC driver.
A slot which is both DPC- and hotplug-capable is currently powered off by
pciehp once DPC is triggered (due to the link change) and powered back up
on successful recovery. That's undesirable, the slot should remain powered
so the hotplugged device remains bound to its driver. DPC notifies the
driver of the error and of successful recovery in pcie_do_recovery() and
the driver may then restore the device to working state.
Moreover, Sinan points out that turning off slot power by pciehp may foil
recovery by DPC: Power off/on is a cold reset concurrently to DPC's warm
reset. Sathyanarayanan reports extended delays or failure in link
retraining by DPC if pciehp brings down the slot.
Fix by detecting whether a Link Down event is caused by DPC and awaiting
recovery if so. On successful recovery, ignore both the Link Down and the
subsequent Link Up event.
Afterwards, check whether the link is down to detect surprise-removal or
another DPC event immediately after DPC recovery. Ensure that the
corresponding DLLSC event is not ignored by synthesizing it and invoking
irq_wake_thread() to trigger a re-run of pciehp_ist().
The IRQ threads of the hotplug and DPC drivers, pciehp_ist() and
dpc_handler(), race against each other. If pciehp is faster than DPC, it
will wait until DPC recovery completes.
Recovery consists of two steps: The first step (waiting for link
disablement) is recognizable by pciehp through a set DPC Trigger Status
bit. The second step (waiting for link retraining) is recognizable through
a newly introduced PCI_DPC_RECOVERING flag.
If DPC is faster than pciehp, neither of the two flags will be set and
pciehp may glean the recovery status from the new PCI_DPC_RECOVERED flag.
The flag is zero if DPC didn't occur at all, hence DLLSC events are not
ignored by default.
pciehp waits up to 4 seconds before assuming that DPC recovery failed and
bringing down the slot. This timeout is not taken from the spec (it
doesn't mandate one) but based on a report from Yicong Yang that DPC may
take a bit more than 3 seconds on HiSilicon's Kunpeng platform.
The timeout is necessary because the DPC Trigger Status bit may never
clear: On Root Ports which support RP Extensions for DPC, the DPC driver
polls the DPC RP Busy bit for up to 1 second before giving up on DPC
recovery. Without the timeout, pciehp would then wait indefinitely for DPC
to complete.
This commit draws inspiration from previous attempts to synchronize DPC
with pciehp:
By Sinan Kaya, August 2018:
https://lore.kernel.org/linux-pci/20180818065126.77912-1-okaya@kernel.org/
By Ethan Zhao, October 2020:
https://lore.kernel.org/linux-pci/20201007113158.48933-1-haifeng.zhao@intel.com/
By Kuppuswamy Sathyanarayanan, March 2021:
https://lore.kernel.org/linux-pci/59cb30f5e5ac6d65427ceaadf1012b2ba8dbf66c.1615606143.git.sathyanarayanan.kuppuswamy@linux.intel.com/
Link: https://lore.kernel.org/r/0be565d97438fe2a6d57354b3aa4e8626952a00b.1619857124.git.lukas@wunner.de
Reported-by: Sinan Kaya <okaya@kernel.org>
Reported-by: Ethan Zhao <haifeng.zhao@intel.com>
Reported-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Tested-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Keith Busch <kbusch@kernel.org>
The sysfs_emit() and sysfs_emit_at() functions were introduced to make
it less ambiguous which function is preferred when writing to the output
buffer in a device attribute's "show" callback [1].
Convert the PCI sysfs object "show" functions from sprintf(), snprintf()
and scnprintf() to sysfs_emit() and sysfs_emit_at() accordingly, as the
latter is aware of the PAGE_SIZE buffer and correctly returns the number
of bytes written into the buffer.
No functional change intended.
[1] Documentation/filesystems/sysfs.rst
Related commit: ad025f8e46 ("PCI/sysfs: Use sysfs_emit() and
sysfs_emit_at() in "show" functions").
Link: https://lore.kernel.org/r/20210603000112.703037-2-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
- add support for system call stack randomization.
- handle stale PCI deconfiguration events.
- couple of defconfig updates.
- some fixes and cleanups.
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Merge tag 's390-5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Heiko Carstens:
- add support for system call stack randomization
- handle stale PCI deconfiguration events
- couple of defconfig updates
- some fixes and cleanups
* tag 's390-5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility
s390/entry: add support for syscall stack randomization
s390/configs: change CONFIG_VIRTIO_CONSOLE to "m"
s390/cio: remove invalid condition on IO_SCH_UNREG
s390/cpumf: remove call to perf_event_update_userpage
s390/cpumf: move counter set size calculation to common place
s390/cpumf: beautify if-then-else indentation
s390/configs: enable CONFIG_PCI_IOV
s390/pci: handle stale deconfiguration events
s390/pci: rename zpci_configure_device()
With zpci_configure_device() now always called on a device that has
already been configured on the platform level its name has become
misleading. Rename it to zpci_scan_configured_device() to signify that
the function now only handles the correct scanning of a newly configured
PCI function taking care of the special handling necessary for function
0 and functions parked waiting for a PCI bus that can't be created
without first seeing function 0.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Currently zpci_configure_device() can be called on a zPCI function in
two completely different states. Either the underlying zPCI function has
already been configured by the platform and we are only doing the
scanning to get it usable by Linux drivers. Or the underlying function
is in Standby and we first do an SCLP to get it configured. This makes
zpci_configure_device() harder to reason about. Since calling
zpci_configure_device() on a function in Standby only happens in
enable_slot() simply pull out the SCLP call and setting of zdev->state
and thus call zpci_configure_device() under the same circumstances as
in the event handling code.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
In enable_slot(), if pci_get_slot() returns NULL, we clear the SLOT_ENABLED
flag. When pci_get_slot() finds a device, it increments the device's
reference count. In this case, we did not call pci_dev_put() to decrement
the reference count, so the memory of the device (struct pci_dev type) will
eventually leak.
Call pci_dev_put() to decrement its reference count when pci_get_slot()
returns a PCI device.
Link: https://lore.kernel.org/r/b411af88-5049-a1c6-83ac-d104a1f429be@huawei.com
Signed-off-by: Feilong Lin <linfeilong@huawei.com>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
A zPCI event with PEC 0x0301 for an existing zPCI device goes through
the same actions as enable_slot(). Similarly a zPCI event with PEC
0x0303 does the same steps as disable_slot().
We can thus unify both actions as zpci_configure_device() respectively
zpci_deconfigure_device().
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The current zdev->state mixes the configuration states supported by CLP
with an additional Online state which is used inconsistently to include
enabled zPCI functions which are not yet visible to the common PCI
subsytem. In preparation for a clean separation between architected
configuration states and fine grained function states remove the Online
function state.
Where we previously checked for Online it is more accurate to check if
the function is enabled to avoid an edge case where a disabled device
was still treated as Online. This also simplifies checks whether
a function is configured as this is now directly reflected by its
function state.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Fix a possible stack corruption and subsequent DLPAR failure in the rpadlpar_io
PCI hotplug driver.
Two build fixes for uncommon configurations.
Thanks to Christophe Leroy, Tyrel Datwyler.
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Merge tag 'powerpc-5.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
- Fix a possible stack corruption and subsequent DLPAR failure in the
rpadlpar_io PCI hotplug driver
- Two build fixes for uncommon configurations
Thanks to Christophe Leroy and Tyrel Datwyler.
* tag 'powerpc-5.12-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
PCI: rpadlpar: Fix potential drc_name corruption in store functions
powerpc: Force inlining of cpu_has_feature() to avoid build failure
powerpc/vdso32: Add missing _restgpr_31_x to fix build failure
Both add_slot_store() and remove_slot_store() try to fix up the
drc_name copied from the store buffer by placing a NUL terminator at
nbyte + 1 or in place of a '\n' if present. However, the static buffer
that we copy the drc_name data into is not zeroed and can contain
anything past the n-th byte.
This is problematic if a '\n' byte appears in that buffer after nbytes
and the string copied into the store buffer was not NUL terminated to
start with as the strchr() search for a '\n' byte will mark this
incorrectly as the end of the drc_name string resulting in a drc_name
string that contains garbage data after the n-th byte.
Additionally it will cause us to overwrite that '\n' byte on the stack
with NUL, potentially corrupting data on the stack.
The following debugging shows an example of the drmgr utility writing
"PHB 4543" to the add_slot sysfs attribute, but add_slot_store()
logging a corrupted string value.
drmgr: drmgr: -c phb -a -s PHB 4543 -d 1
add_slot_store: drc_name = PHB 4543°|<82>!, rc = -19
Fix this by using strscpy() instead of memcpy() to ensure the string
is NUL terminated when copied into the static drc_name buffer.
Further, since the string is now NUL terminated the code only needs to
change '\n' to '\0' when present.
Cc: stable@vger.kernel.org
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
[mpe: Reformat change log and add mention of possible stack corruption]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210315214821.452959-1-tyreld@linux.ibm.com
In commit 05bc1be6db ("s390/pci: create zPCI bus") we removed the
pci_dev_put() call matching the earlier pci_get_slot() done as part of
__zpci_event_availability(). This was based on the wrong understanding
that the device_put() done as part of pci_destroy_device() would counter
the pci_get_slot() when it only counters the initial reference. This
same understanding and existing bad example also lead to not doing
a pci_dev_put() in zpci_remove_device().
Since releasing the PCI devices, unlike releasing the PCI slot, does not
print any debug message for testing I added one in pci_release_dev().
This revealed that we are indeed leaking the PCI device on PCI
hotunplug. Further testing also revealed another missing pci_dev_put() in
disable_slot().
Fix this by adding the missing pci_dev_put() in disable_slot() and fix
zpci_remove_device() with the correct pci_dev_put() calls. Also instead
of calling pci_get_slot() in __zpci_event_availability() to determine if
a PCI device is registered and then doing the same again in
zpci_remove_device() do this once in zpci_remove_device() which makes
sure that the pdev in __zpci_event_availability() is only used for the
result of pci_scan_single_device() which does not need a reference count
decremnt as its ownership goes to the PCI bus.
Also move the check if zdev->zbus->bus is set into zpci_remove_device()
since it may be that we're removing a device with devfn != 0 which never
had a PCI bus. So we can still set the pdev->error_state to indicate
that the device is not usable anymore, add a flag to set the error state.
Fixes: 05bc1be6db ("s390/pci: create zPCI bus")
Cc: <stable@vger.kernel.org> # 5.8+: e1bff843cd s390/pci: remove superfluous zdev->zbus check
Cc: <stable@vger.kernel.org> # 5.8+: ba764dd703 s390/pci: refactor zpci_create_device()
Cc: <stable@vger.kernel.org> # 5.8+
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Remove the 'acpiphp_callback' typedef as it is not used.
Link: https://lore.kernel.org/r/1613443120-4279-1-git-send-email-chen45464546@163.com
Signed-off-by: Chen Lin <chen.lin5@zte.com.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The value of the constant POWER_FAILURE assigned to the variable rc
after the power fault check is never used for anything, so remove it.
Addresses-Coverity-ID: 1226899 ("Unused value")
Link: https://lore.kernel.org/r/20200923025225.471459-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
When a PCIe card is hot-removed, the Presence Detect State and Data Link
Layer Link Active bits often do not clear simultaneously. I've seen delays
of up to 244 msec between the two events with Thunderbolt.
After pciehp has brought down the slot in response to the first event, the
other bit may still be set. It's not discernible whether it's set because
a new card is already in the slot or if it will soon clear. So pciehp
tries to bring up the slot and in the latter case fails with a bunch of
messages, some of them at KERN_ERR severity. If the slot is no longer
occupied, the messages are false positives and annoy users.
Stuart Hayes reports the following splat on hot removal:
KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Link Up
KERN_INFO pcieport 0000:3c:06.0: pciehp: Timeout waiting for Presence Detect
KERN_ERR pcieport 0000:3c:06.0: pciehp: link training error: status 0x0001
KERN_ERR pcieport 0000:3c:06.0: pciehp: Failed to check link status
Dongdong Liu complains about a similar splat:
KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Link Down
KERN_INFO iommu: Removing device 0000:87:00.0 from group 12
KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Card present
KERN_INFO pcieport 0000:80:10.0: Data Link Layer Link Active not set in 1000 msec
KERN_ERR pciehp 0000:80:10.0:pcie004: Failed to check link status
Users are particularly irritated to see a bringup attempt even though the
slot was explicitly brought down via sysfs. In a perfect world, we could
avoid this by setting Link Disable on slot bringdown and re-enabling it
upon a Presence Detect State change. In reality however, there are broken
hotplug ports which hardwire Presence Detect to zero, see 80696f9914
("PCI: pciehp: Tolerate Presence Detect hardwired to zero"). Conversely,
PCIe r1.0 hotplug ports hardwire Link Active to zero because Link Active
Reporting wasn't specified before PCIe r1.1. On unplug, some ports first
clear Presence then Link (see Stuart Hayes' splat) whereas others use the
inverse order (see Dongdong Liu's splat). To top it off, there are hotplug
ports which flap the Presence and Link bits on slot bringup, see
6c35a1ac3d ("PCI: pciehp: Tolerate initially unstable link").
pciehp is designed to work with all of these variants. Surplus attempts at
slot bringup are a lesser evil than not being able to bring up slots at
all. Although we could try to perfect the behavior for specific hotplug
controllers, we'd risk breaking others or increasing code complexity.
But we can certainly minimize annoyance by emitting only a single message
with KERN_INFO severity if bringup is unsuccessful:
* Drop the "Timeout waiting for Presence Detect" message in
pcie_wait_for_presence(). The sole caller of that function,
pciehp_check_link_status(), ignores the timeout and carries on. It emits
error messages of its own and I don't think this particular message adds
much value.
* There's a single error condition in pciehp_check_link_status() which
does not emit a message. Adding one allows dropping the "Failed to check
link status" message emitted by board_added() if
pciehp_check_link_status() returns a non-zero integer.
* Tone down all messages in pciehp_check_link_status() to KERN_INFO
severity and rephrase them to look as innocuous as possible. To this
end, move the message emitted by pcie_wait_for_link_delay() to its
callers.
As a result, Stuart Hayes' splat becomes:
KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Link Up
KERN_INFO pcieport 0000:3c:06.0: pciehp: Slot(180): Cannot train link: status 0x0001
Dongdong Liu's splat becomes:
KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): Card present
KERN_INFO pciehp 0000:80:10.0:pcie004: Slot(36): No link
The messages now merely serve as information that presence or link bits
were set a little longer than expected. Bringup failures which are not
false positives are still reported, albeit no longer at KERN_ERR severity.
Link: https://lore.kernel.org/linux-pci/20200310182100.102987-1-stuart.w.hayes@gmail.com/
Link: https://lore.kernel.org/linux-pci/1547649064-19019-1-git-send-email-liudongdong3@huawei.com/
Link: https://lore.kernel.org/r/b45e46fd8a6aa6930aaac9d7718c2e4b787a4e5e.1595935071.git.lukas@wunner.de
Reported-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Reported-by: Dongdong Liu <liudongdong3@huawei.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
For fixing the PF to VF link removal we need to perform some action on
every removal of a zdev from the common PCI subsystem.
So in preparation re-introduce zpci_remove_device() and use that instead
of directly calling the common code functions. This was actually still
declared from earlier code but no longer implemented.
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The sparse tool report build warnings as follows:
drivers/pci/hotplug/rpadlpar_core.c:355:5: warning: symbol 'dlpar_remove_pci_slot' was not declared. Should it be static?
drivers/pci/hotplug/rpadlpar_core.c:461:12: warning: symbol 'rpadlpar_io_init' was not declared. Should it be static?
drivers/pci/hotplug/rpadlpar_core.c:473:6: warning: symbol 'rpadlpar_io_exit' was not declared. Should it be static?
Those functions are not used outside of this file, so mark them static.
Also mark rpadlpar_io_exit() as __exit.
Link: https://lore.kernel.org/r/20200721151735.41181-1-weiyongjun1@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
If context is not NULL in acpiphp_grab_context(), but the
is_going_away flag is set for the device's parent, the reference
counter of the context needs to be decremented before returning
NULL or the context will never be freed, so make that happen.
Fixes: edf5bf34d4 ("ACPI / dock: Use callback pointers from devices' ACPI hotplug contexts")
Reported-by: Vasily Averin <vvs@virtuozzo.com>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.
This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.
There are a variety of indentation styles found.
a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'
In order to convert all of them to 1 tab + 'help', I ran the
following commend:
$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
- Add support for multi-function devices in pci code.
- Enable PF-VF linking for architectures using the
pdev->no_vf_scan flag (currently just s390).
- Add reipl from NVMe support.
- Get rid of critical section cleanup in entry.S.
- Refactor PNSO CHSC (perform network subchannel operation) in cio
and qeth.
- QDIO interrupts and error handling fixes and improvements, more
refactoring changes.
- Align ioremap() with generic code.
- Accept requests without the prefetch bit set in vfio-ccw.
- Enable path handling via two new regions in vfio-ccw.
- Other small fixes and improvements all over the code.
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Merge tag 's390-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:
- Add support for multi-function devices in pci code.
- Enable PF-VF linking for architectures using the pdev->no_vf_scan
flag (currently just s390).
- Add reipl from NVMe support.
- Get rid of critical section cleanup in entry.S.
- Refactor PNSO CHSC (perform network subchannel operation) in cio and
qeth.
- QDIO interrupts and error handling fixes and improvements, more
refactoring changes.
- Align ioremap() with generic code.
- Accept requests without the prefetch bit set in vfio-ccw.
- Enable path handling via two new regions in vfio-ccw.
- Other small fixes and improvements all over the code.
* tag 's390-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (52 commits)
vfio-ccw: make vfio_ccw_regops variables declarations static
vfio-ccw: Add trace for CRW event
vfio-ccw: Wire up the CRW irq and CRW region
vfio-ccw: Introduce a new CRW region
vfio-ccw: Refactor IRQ handlers
vfio-ccw: Introduce a new schib region
vfio-ccw: Refactor the unregister of the async regions
vfio-ccw: Register a chp_event callback for vfio-ccw
vfio-ccw: Introduce new helper functions to free/destroy regions
vfio-ccw: document possible errors
vfio-ccw: Enable transparent CCW IPL from DASD
s390/pci: Log new handle in clp_disable_fh()
s390/cio, s390/qeth: cleanup PNSO CHSC
s390/qdio: remove q->first_to_kick
s390/qdio: fix up qdio_start_irq() kerneldoc
s390: remove critical section cleanup from entry.S
s390: add machine check SIGP
s390/pci: ioremap() align with generic code
s390/ap: introduce new ap function ap_get_qdev()
Documentation/s390: Update / remove developerWorks web links
...
- Update the ACPICA code in the kernel to upstream revision
20200430:
* Move acpi_gbl_next_cmd_num definition (Erik Kaneda).
* Ignore AE_ALREADY_EXISTS status in the disassembler when parsing
create operators (Erik Kaneda).
* Add status checks to the dispatcher (Erik Kaneda).
* Fix required parameters for _NIG and _NIH (Erik Kaneda).
* Make acpi_protocol_lengths static (Yue Haibing).
- Fix ACPI table reference counting errors in several places, mostly
in error code paths (Hanjun Guo).
- Extend the Generic Event Device (GED) driver to support _Exx and
_Lxx handler methods (Ard Biesheuvel).
- Add new acpi_evaluate_reg() helper and modify the ACPI PCI hotplug
code to use it (Hans de Goede).
- Add new DPTF battery participant driver and make the DPFT power
participant driver create more sysfs device attributes (Srinivas
Pandruvada).
- Improve the handling of memory failures in APEI (James Morse).
- Add new blacklist entry for Acer TravelMate 5735Z to the backlight
driver (Paul Menzel).
- Add i2c address for thermal control to the PMIC driver (Mauro
Carvalho Chehab).
- Allow the ACPI processor idle driver to work on platforms with
only one ACPI C-state present (Zhang Rui).
- Fix kobject reference count leaks in error code paths in two
places (Qiushi Wu).
- Delete unused proc filename macros and make some symbols static
(Pascal Terjan, Zheng Zengkai, Zou Wei).
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Merge tag 'acpi-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI updates from Rafael Wysocki:
"These update the ACPICA code in the kernel to upstream revision
20200430, fix several reference counting errors related to ACPI
tables, add _Exx / _Lxx support to the GED driver, add a new
acpi_evaluate_reg() helper, add new DPTF battery participant driver
and extend the DPFT power participant driver, improve the handling of
memory failures in the APEI code, add a blacklist entry to the
backlight driver, update the PMIC driver and the processor idle
driver, fix two kobject reference count leaks, and make a few janitory
changes.
Specifics:
- Update the ACPICA code in the kernel to upstream revision 20200430:
- Move acpi_gbl_next_cmd_num definition (Erik Kaneda).
- Ignore AE_ALREADY_EXISTS status in the disassembler when parsing
create operators (Erik Kaneda).
- Add status checks to the dispatcher (Erik Kaneda).
- Fix required parameters for _NIG and _NIH (Erik Kaneda).
- Make acpi_protocol_lengths static (Yue Haibing).
- Fix ACPI table reference counting errors in several places, mostly
in error code paths (Hanjun Guo).
- Extend the Generic Event Device (GED) driver to support _Exx and
_Lxx handler methods (Ard Biesheuvel).
- Add new acpi_evaluate_reg() helper and modify the ACPI PCI hotplug
code to use it (Hans de Goede).
- Add new DPTF battery participant driver and make the DPFT power
participant driver create more sysfs device attributes (Srinivas
Pandruvada).
- Improve the handling of memory failures in APEI (James Morse).
- Add new blacklist entry for Acer TravelMate 5735Z to the backlight
driver (Paul Menzel).
- Add i2c address for thermal control to the PMIC driver (Mauro
Carvalho Chehab).
- Allow the ACPI processor idle driver to work on platforms with only
one ACPI C-state present (Zhang Rui).
- Fix kobject reference count leaks in error code paths in two places
(Qiushi Wu).
- Delete unused proc filename macros and make some symbols static
(Pascal Terjan, Zheng Zengkai, Zou Wei)"
* tag 'acpi-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
ACPI: CPPC: Fix reference count leak in acpi_cppc_processor_probe()
ACPI: sysfs: Fix reference count leak in acpi_sysfs_add_hotplug_profile()
ACPI: GED: use correct trigger type field in _Exx / _Lxx handling
ACPI: DPTF: Add battery participant driver
ACPI: DPTF: Additional sysfs attributes for power participant driver
ACPI: video: Use native backlight on Acer TravelMate 5735Z
arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work
ACPI: APEI: Kick the memory_failure() queue for synchronous errors
mm/memory-failure: Add memory_failure_queue_kick()
ACPI / PMIC: Add i2c address for thermal control
ACPI: GED: add support for _Exx / _Lxx handler methods
ACPI: Delete unused proc filename macros
ACPI: hotplug: PCI: Use the new acpi_evaluate_reg() helper
ACPI: utils: Add acpi_evaluate_reg() helper
ACPI: debug: Make two functions static
ACPI: sleep: Put the FACS table after using it
ACPI: scan: Put SPCR and STAO table after using it
ACPI: EC: Put the ACPI table after using it
ACPI: APEI: Put the HEST table for error path
ACPI: APEI: Put the error record serialization table for error path
...
shpchp_unconfigure_device() always returned 0, so there's no reason for a
return value. In addition, remove_board() checked the return value for
possible error which is unnecessary.
Convert shpchp_unconfigure_device() to a void function and remove the
return value check. This addresses the following Coccinelle warning:
drivers/pci/hotplug/shpchp_pci.c:66:5-7: Unneeded variable: "rc". Return "0" on line 86
Link: https://lore.kernel.org/r/20200521190457.1066600-1-kw@linux.com
Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Use the new acpi_evaluate_reg() helper in the acpiphp_glue.c code.
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The Physical function should not be disabled until no virtual
functions depends on it.
Let's force the user to first use echo 0 > sriov_numfs before
allowing to disable the PF with echo 0 > power.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
We allow multiple functions on a single bus.
We suppress the ZPCI_DEVFN definition and replace its
occurences with zpci->devfn.
We verify the number of device during the registration.
There can never be more domains in use than existing
devices, so we do not need to verify the count of domain
after having verified the count of devices.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The zPCI bus is in charge to handle common zPCI resources for
zPCI devices.
Creating the zPCI bus, the PCI bus, the zPCI devices and the
PCI devices and hotplug slots
done in a specific order:
- PCI hotplug slot creation needs a PCI bus
- PCI bus needs a PCI domain
which is reported by the pci_domain_nr() when setting up the
host bridge
- PCI domain is set from the zPCI with devfn 0
this is necessary to have a reproducible enumeration
Therefore we can not create devices or hotplug slots for any PCI
device associated with a zPCI device before having discovered
the function zero of the bus.
The discovery and initialization of devices can be done at several
points in the code:
- On Events, serialized in a thread context
- On initialization, in the kernel init thread context
- When powering on the hotplug slot, in a user thread context
The removal of devices and their parent bus may also be done on
events or for devices when powering down the slot.
To guarantee the existence of the bus and devices until they are
no more needed we use kref in zPCI bus and introduce a reference
count in the zPCI devices.
In this patch the zPCI bus still only accept a device with
a devfn 0.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>