- Add device_add_of_node() to set dev->of_node and dev->fwnode only if they
haven't been set already (Herve Codina)
- Allow of_pci_set_address() to set the DT address property for root bus
nodes, where there is no PCI bridge to supply the PCI bus/device/function
part of the property (Herve Codina)
- Create DT nodes for PCI host bridges to enable loading device tree
overlays to create platform devices for PCI devices that have several
features that require multiple drivers (Herve Codina)
* pci/devtree-create:
PCI: of: Create device tree PCI host bridge node
PCI: of_property: Constify parameter in of_pci_get_addr_flags()
PCI: of_property: Add support for NULL pdev in of_pci_set_address()
PCI: of: Use device_{add,remove}_of_node() to attach of_node to existing device
driver core: Introduce device_{add,remove}_of_node()
- Use pci_resource_n() to simplify BAR/window resource lookup (Ilpo
Järvinen)
- Fix typo that repeatedly distributed resources to a bridge instead of
iterating over subordinate bridges, which resulted in too little space to
assign some BARs (Kai-Heng Feng)
- Relax bridge window tail sizing for optional resources, e.g., IOV BARs,
to avoid failures when removing and re-adding devices (Ilpo Järvinen)
- Fix a double counting error for I/O resources, as we previously did for
memory resources (Ilpo Järvinen)
- Use resource_set_{range,size}() helpers in more places (Ilpo Järvinen)
- Add pci_resource_is_iov() to identify IOV resources (Ilpo Järvinen)
- Add pci_resource_num() to look up the BAR number from the resource
pointer (Ilpo Järvinen)
- Add restore_dev_resource() to simplify code that resources saved device
resources (Ilpo Järvinen)
- Allow drivers to enable devices even if we haven't assigned optional IOV
resources to them (Ilpo Järvinen)
- Improve debug output during resource reallocation (Ilpo Järvinen)
- Rework handling of optional resources (IOV BARs, ROMs) to reduce failures
if we can't allocate them (Ilpo Järvinen)
- Move declarations of pci_rescan_bus_bridge_resize(),
pci_reassign_bridge_resources(), and CardBus-related sizes from
include/linux/pci.h to drivers/pci/pci.h since they're not used outside
the PCI core (Ilpo Järvinen)
- Make pci_setup_bridge() static (Ilpo Järvinen)
- Fix a NULL dereference in the SR-IOV VF creation error path (Shay Drory)
- Fix s390 mmio_read/write syscalls, which didn't cause page faults in some
cases, which broke vfio-pci lazy mapping on first access (Niklas
Schnelle)
- Add pdev->non_mappable_bars to replace CONFIG_VFIO_PCI_MMAP, which was
disabled only for s390 (Niklas Schnelle)
- Support mmap of PCI resources on s390 except for ISM devices (Niklas
Schnelle)
* pci/resource:
s390/pci: Support mmap() of PCI resources except for ISM devices
s390/pci: Introduce pdev->non_mappable_bars and replace VFIO_PCI_MMAP
s390/pci: Fix s390_mmio_read/write syscall page fault handling
PCI: Fix NULL dereference in SR-IOV VF creation error path
PCI: Move cardbus IO size declarations into pci/pci.h
PCI: Make pci_setup_bridge() static
PCI: Move resource reassignment func declarations into pci/pci.h
PCI: Move pci_rescan_bus_bridge_resize() declaration to pci/pci.h
PCI: Fix BAR resizing when VF BARs are assigned
PCI: Do not claim to release resource falsely
PCI: Increase Resizable BAR support from 512 GB to 128 TB
PCI: Rework optional resource handling
PCI: Perform reset_resource() and build fail list in sync
PCI: Use res->parent to check if resource is assigned
PCI: Add debug print when releasing resources before retry
PCI: Indicate optional resource assignment failures
PCI: Always have realloc_head in __assign_resources_sorted()
PCI: Extend enable to check for any optional resource
PCI: Add restore_dev_resource()
PCI: Remove incorrect comment from pci_reassign_resource()
PCI: Consolidate assignment loop next round preparation
PCI: Rename retval to ret
PCI: Use while loop and break instead of gotos
PCI: Refactor pdev_sort_resources() & __dev_sort_resources()
PCI: Converge return paths in __assign_resources_sorted()
PCI: Add dev & res local variables to resource assignment funcs
PCI: Add pci_resource_num() helper
PCI: Check resource_size() separately
PCI: Add pci_resource_is_iov() to identify IOV resources
PCI: Use resource_set_{range,size}() helpers
PCI: Use SZ_* instead of literals in setup-bus.c
PCI: Fix old_size lower bound in calculate_iosize() too
PCI: Allow relaxed bridge window tail sizing for optional resources
PCI: Simplify size1 assignment logic
PCI: Use min_align, not unrelated add_align, for size0
PCI: Remove add_align overwrite unrelated to size0
PCI: Use downstream bridges for distributing resources
PCI: Cleanup dev->resource + resno to use pci_resource_n()
- Log debug messages about reset methods being used (Bjorn Helgaas)
- Avoid reset when it has been disabled via sysfs (Nishanth Aravamudan)
* pci/reset:
PCI: Avoid reset when disabled via sysfs
PCI: Log debug messages about reset method
- Create pwrctrl devices in pci_scan_device() to make it more symmetric
with pci_pwrctrl_unregister() and make pwrctrl devices for PCI bridges
possible (Manivannan Sadhasivam)
- Unregister pwrctrl devices in pci_destroy_dev() so DOE, ASPM, etc. can
still access devices after pci_stop_dev() (Manivannan Sadhasivam)
- If there's a pwrctrl device for a PCI device, skip scanning it because
the pwrctrl core will rescan the bus after the device is powered on
(Manivannan Sadhasivam)
- Add a pwrctrl driver for PCI slots based on voltage regulators described
via devicetree (Manivannan Sadhasivam)
* pci/pwrctrl:
PCI/pwrctrl: Add pwrctrl driver for PCI slots
dt-bindings: vendor-prefixes: Document the 'pciclass' prefix
PCI/pwrctrl: Skip scanning for the device further if pwrctrl device is created
PCI/pwrctrl: Move pci_pwrctrl_unregister() to pci_destroy_dev()
PCI/pwrctrl: Move creation of pwrctrl devices to pci_scan_device()
- Drop shpchp module init/exit logging (Ilpo Järvinen)
- Replace shpchp dbg() with ctrl_dbg() and remove unused dbg(), err(),
info(), warn() wrappers (Ilpo Järvinen)
- Drop 'shpchp_debug' module parameter in favor of standard dynamic
debugging (Ilpo Järvinen)
- Drop unused .get_power(), .set_power() function pointers (Guilherme
Giacomo Simoes)
- Drop superfluous pci_hotplug_slot_list (Lukas Wunner)
- Drop superfluous try_module_get() calls (Lukas Wunner)
- Drop superfluous NULL pointer checks (Lukas Wunner)
- Pass struct hotplug_slot pointers directly to avoid backpointer
dereferencing in has_*_file() (Lukas Wunner)
- Inline pci_hp_{create,remove}_module_link() to reduce exported symbols
(Lukas Wunner)
- Disable hotplug interrupts in portdrv only when pciehp is not enabled to
prevent issuing two hotplug commands too close together (Feng Tang)
- Skip pciehp 'device replaced' check if the device has been removed to
address a common deadlock when resuming after a device was removed during
system sleep (Lukas Wunner)
- Don't enable pciehp hotplug interupt when resuming in poll mode (Ilpo
Järvinen)
* pci/hotplug:
PCI: pciehp: Don't enable HPIE when resuming in poll mode
PCI: pciehp: Avoid unnecessary device replacement check
PCI/portdrv: Only disable pciehp interrupts early when needed
PCI: hotplug: Inline pci_hp_{create,remove}_module_link()
PCI: hotplug: Avoid backpointer dereferencing in has_*_file()
PCI: hotplug: Drop superfluous NULL pointer checks in has_*_file()
PCI: hotplug: Drop superfluous try_module_get() calls
PCI: hotplug: Drop superfluous pci_hotplug_slot_list
PCI: cpcihp: Remove unused .get_power() and .set_power()
PCI: shpchp: Remove 'shpchp_debug' module parameter
PCI: shpchp: Remove unused logging wrappers
PCI: shpchp: Change dbg() -> ctrl_dbg()
PCI: shpchp: Remove logging from module init/exit functions
- Enable Configuration RRS SV early instead of during child bus scanning
(Bjorn Helgaas)
- Cache offset of Resizable BAR capability to avoid redundant searches for
it (Bjorn Helgaas)
- Fix reference leaks in pci_register_host_bridge() and
pci_alloc_child_bus() (Ma Ke)
- Drop put_device() in pci_register_host_bridge() left over from converting
device_register() to device_add() (Dan Carpenter)
* pci/enumeration:
PCI: Remove stray put_device() in pci_register_host_bridge()
PCI: Fix reference leak in pci_alloc_child_bus()
PCI: Fix reference leak in pci_register_host_bridge()
PCI: Cache offset of Resizable BAR capability
PCI: Enable Configuration RRS SV early
- Rename DOE 'protocol' to 'feature' to follow spec terminology (Alistair
Francis)
- Expose supported DOE features via sysfs (Alistair Francis)
- Allow DOE support to be enabled even if CXL isn't enabled (Alistair
Francis)
* pci/doe:
PCI/DOE: Allow enabling DOE without CXL
PCI/DOE: Expose DOE features via sysfs
PCI/DOE: Rename Discovery Response Data Object Contents to type
PCI/DOE: Rename DOE protocol to feature
- Enlarge the devres table[] to accommodate bridge windows, ROM, IOV BARs,
etc (Philipp Stanner)
- Validate BAR index in devres interfaces (Philipp Stanner)
* pci/devres:
PCI: Check BAR index for validity
PCI: Fix wrong length of devres array
- Add set_pcie_speed.sh to TEST_PROGS to fix issue when executing the
set_pcie_cooling_state.sh test case (Yi Lai)
- Fix the pcie_bwctrl_select_speed() return value in cases where a
non-compliant device doesn't advertise valid supported speeds (Ilpo
Järvinen)
- Avoid a NULL pointer dereference when we run out of bus numbers to assign
for a bridge secondary bus (Lukas Wunner)
* pci/bwctrl:
PCI/bwctrl: Fix NULL pointer dereference on bus number exhaustion
PCI/bwctrl: Fix pcie_bwctrl_select_speed() return type
selftests/pcie_bwctrl: Add 'set_pcie_speed.sh' to TEST_PROGS
- Delay pcie_link_state deallocation to avoid dangling pointers that cause
invalid references during hot-unplug (Daniel Stodden)
* pci/aspm:
PCI/ASPM: Fix link state exit during switch upstream function removal
- Implement local aer_printk() since AER is the only place that prints a
message with level depending on the error severity (Ilpo Järvinen)
* pci/aer:
PCI/ERR: Handle TLP Log in Flit mode
PCI: Track Flit Mode Status & print it with link status
PCI/AER: Descope pci_printk() to aer_printk()
When BIOS neglects to assign bus numbers to PCI bridges, the kernel
attempts to correct that during PCI device enumeration. If it runs out
of bus numbers, no pci_bus is allocated and the "subordinate" pointer in
the bridge's pci_dev remains NULL.
The PCIe bandwidth controller erroneously does not check for a NULL
subordinate pointer and dereferences it on probe.
Bandwidth control of unusable devices below the bridge is of questionable
utility, so simply error out instead. This mirrors what PCIe hotplug does
since commit 62e4492c30 ("PCI: Prevent NULL dereference during pciehp
probe").
The PCI core emits a message with KERN_INFO severity if it has run out of
bus numbers. PCIe hotplug emits an additional message with KERN_ERR
severity to inform the user that hotplug functionality is disabled at the
bridge. A similar message for bandwidth control does not seem merited,
given that its only purpose so far is to expose an up-to-date link speed
in sysfs and throttle the link speed on certain laptops with limited
Thermal Design Power. So error out silently.
User-visible messages:
pci 0000:16:02.0: bridge configuration invalid ([bus 00-00]), reconfiguring
[...]
pci_bus 0000:45: busn_res: [bus 45-74] end is updated to 74
pci 0000:16:02.0: devices behind bridge are unusable because [bus 45-74] cannot be assigned for them
[...]
pcieport 0000:16:02.0: pciehp: Hotplug bridge without secondary bus, ignoring
[...]
BUG: kernel NULL pointer dereference
RIP: pcie_update_link_speed
pcie_bwnotif_enable
pcie_bwnotif_probe
pcie_port_probe_service
really_probe
Fixes: 665745f274 ("PCI/bwctrl: Re-add BW notification portdrv as PCIe BW controller")
Reported-by: Wouter Bijlsma <wouter@wouterbijlsma.nl>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219906
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Tested-by: Wouter Bijlsma <wouter@wouterbijlsma.nl>
Cc: stable@vger.kernel.org # v6.13+
Link: https://lore.kernel.org/r/3b6c8d973aedc48860640a9d75d20528336f1f3c.1742669372.git.lukas@wunner.de
PCIe r6.0 added support for Data Object Exchange (DOE). When DOE is
supported, the DOE Discovery Feature must be implemented per PCIe r6.1, sec
6.30.1.1. DOE allows a requester to obtain information about the other DOE
features supported by the device.
The kernel already queries the DOE features supported and caches the
values. Expose the values in sysfs to allow user space to determine which
DOE features are supported by the PCIe device.
By exposing the information to userspace, tools like lspci can relay the
information to users. By listing all of the supported features we can allow
userspace to parse the list, which might include vendor specific features
as well as yet to be supported features.
As the DOE Discovery feature must always be supported we treat it as a
special named attribute case. This allows the usual PCI attribute_group
handling to correctly create the doe_features directory when registering
pci_doe_sysfs_group (otherwise it doesn't and sysfs_add_file_to_group()
will seg fault).
After this patch is supported you can see something like this when
attaching a DOE device:
$ ls /sys/devices/pci0000:00/0000:00:02.0//doe*
0001:01 0001:02 doe_discovery
Link: https://lore.kernel.org/r/20250306075211.1855177-3-alistair@alistair23.me
Signed-off-by: Alistair Francis <alistair@alistair23.me>
[bhelgaas: drop pci_doe_sysfs_init() stub return, make
DEVICE_ATTR_RO(doe_discovery) static]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
So far s390 does not allow mmap() of PCI resources to user-space via the
usual mechanisms, though it does use it for RDMA. For the PCI sysfs
resource files and /proc/bus/pci it defines neither HAVE_PCI_MMAP nor
ARCH_GENERIC_PCI_MMAP_RESOURCE. For vfio-pci s390 previously relied on
disabled VFIO_PCI_MMAP and now relies on setting pdev->non_mappable_bars
for all devices.
This is partly because access to mapped PCI resources from user-space
requires special PCI load/store memory-I/O (MIO) instructions, or the
special MMIO syscalls when these are not available. Still, such access is
possible and useful not just for RDMA, in fact not being able to mmap() PCI
resources has previously caused extra work when testing devices.
One thing that doesn't work with PCI resources mapped to user-space though
is the s390 specific virtual ISM device. Not only because the BAR size of
256 TiB prevents mapping the whole BAR but also because access requires use
of the legacy PCI instructions which are not accessible to user-space on
systems with the newer MIO PCI instructions.
Now with the pdev->non_mappable_bars flag ISM can be excluded from mapping
its resources while making this functionality available for all other PCI
devices. To this end introduce a minimal implementation of PCI_QUIRKS and
use that to set pdev->non_mappable_bars for ISM devices only. Then also set
ARCH_GENERIC_PCI_MMAP_RESOURCE to take advantage of the generic
implementation of pci_mmap_resource_range() enabling only the newer sysfs
mmap() interface. This follows the recommendation in
Documentation/PCI/sysfs-pci.rst.
Link: https://lore.kernel.org/r/20250226-vfio_pci_mmap-v7-3-c5c0f1d26efd@linux.ibm.com
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The ability to map PCI resources to user-space is controlled by global
defines. For vfio there is VFIO_PCI_MMAP which is only disabled on s390 and
controls mapping of PCI resources using vfio-pci with a fallback option via
the pread()/pwrite() interface.
For the PCI core there is ARCH_GENERIC_PCI_MMAP_RESOURCE which enables a
generic implementation for mapping PCI resources plus the newer sysfs
interface. Then there is HAVE_PCI_MMAP which can be used with custom
definitions of pci_mmap_resource_range() and the historical /proc/bus/pci
interface. Both mechanisms are all or nothing.
For s390 mapping PCI resources is possible and useful for testing and
certain applications such as QEMU's vfio-pci based user-space NVMe driver.
For certain devices, however access to PCI resources via mappings to
user-space is not possible and these must be excluded from the general PCI
resource mapping mechanisms.
Introduce pdev->non_mappable_bars to indicate that a PCI device's BARs can
not be accessed via mappings to user-space. In the future this enables
per-device restrictions of PCI resource mapping.
For now, set this flag for all PCI devices on s390 in line with the
existing, general disable of PCI resource mapping. As s390 is the only user
of the VFI_PCI_MMAP Kconfig options this can already be replaced with a
check of this new flag. Also add similar checks in the other code protected
by HAVE_PCI_MMAP respectively ARCH_GENERIC_PCI_MMAP in preparation for
enabling these for supported devices.
Link: https://lore.kernel.org/lkml/20250212132808.08dcf03c.alex.williamson@redhat.com/
Link: https://lore.kernel.org/r/20250226-vfio_pci_mmap-v7-2-c5c0f1d26efd@linux.ibm.com
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The s390 MMIO syscalls when using the classic PCI instructions do not
cause a page fault when follow_pfnmap_start() fails due to the page not
being present. Besides being a general deficiency this breaks vfio-pci's
mmap() handling once VFIO_PCI_MMAP gets enabled as this lazily maps on
first access. Fix this by following a failed follow_pfnmap_start() with
fixup_user_page() and retrying the follow_pfnmap_start(). Also fix
a VM_READ vs VM_WRITE mixup in the read syscall.
Link: https://lore.kernel.org/r/20250226-vfio_pci_mmap-v7-1-c5c0f1d26efd@linux.ibm.com
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
pcie_bwctrl_select_speed() should take __fls() of the speed bit, not return
it as a raw value. Instead of directly returning 2.5GT/s speed bit, simply
assign the fallback speed (2.5GT/s) into supported_speeds variable to share
the normal return path that calls pcie_supported_speeds2target_speed() to
calculate __fls().
This code path is not very likely to execute because
pcie_get_supported_speeds() should provide valid ->supported_speeds but a
spec violating device could fail to synthesize any speed in
pcie_get_supported_speeds(). It could also happen in case the
supported_speeds intersection is empty (also a violation of the current
PCIe specs).
Link: https://lore.kernel.org/r/20250321163103.5145-1-ilpo.jarvinen@linux.intel.com
Fixes: de9a6c8d5d ("PCI/bwctrl: Add pcie_set_target_speed() to set PCIe Link Speed")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCIe hotplug can operate in poll mode without interrupt handlers using a
polling kthread only. eb34da60ed ("PCI: pciehp: Disable hotplug
interrupt during suspend") failed to consider that and enables HPIE
(Hot-Plug Interrupt Enable) unconditionally when resuming the Port.
Only set HPIE if non-poll mode is in use. This makes
pcie_enable_interrupt() match how pcie_enable_notification() already
handles HPIE.
Link: https://lore.kernel.org/r/20250321162114.3939-1-ilpo.jarvinen@linux.intel.com
Fixes: eb34da60ed ("PCI: pciehp: Disable hotplug interrupt during suspend")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Neither pci_reassign_bridge_resources() nor pci_reassign_resource() is used
outside of the PCI subsystem. They seem to be naturally static functions
but since resource fitting/assignment is split between setup-bus.c and
setup-res.c, they fall into different sides of the divide and need to be
declared.
Move the declarations of pci_reassign_bridge_resources() and
pci_reassign_resource() into pci/pci.h to keep them internal to PCI
subsystem.
Link: https://lore.kernel.org/r/20250311174701.3586-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
__resource_resize_store() attempts to release all resources of the device
before attempting the resize. The loop, however, only covers standard BARs
(< PCI_STD_NUM_BARS). If a device has VF BARs that are assigned,
pci_reassign_bridge_resources() finds the bridge window still has some
assigned child resources and returns -NOENT which makes
pci_resize_resource() to detect an error and abort the resize.
Change the release loop to cover all resources up to VF BARs which allows
the resize operation to release the bridge windows and attempt to assigned
them again with the different size.
If SR-IOV is enabled, disallow resize as it requires releasing also IOV
resources.
Link: https://lore.kernel.org/r/20250320142837.8027-1-ilpo.jarvinen@linux.intel.com
Fixes: 91fa127794 ("PCI: Expose PCIe Resizable BAR support via sysfs")
Reported-by: Michał Winiarski <michal.winiarski@intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Many functions in PCI use accessor macros such as pci_resource_len(),
which take a BAR index. That index, however, is never checked for
validity, potentially resulting in undefined behavior by overflowing the
array pci_dev.resource in the macro pci_resource_n().
Since many users of those macros directly assign the accessed value to
an unsigned integer, the macros cannot be changed easily anymore to
return -EINVAL for invalid indexes. Consequently, the problem has to be
mitigated in higher layers.
Add pci_bar_index_valid(). Use it where appropriate.
Link: https://lore.kernel.org/r/20250312080634.13731-4-phasta@kernel.org
Closes: https://lore.kernel.org/all/adb53b1f-29e1-3d14-0e61-351fd2d3ff0d@linux.intel.com/
Reported-by: Bingbu Cao <bingbu.cao@linux.intel.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
[kwilczynski: correct if-statement condition the pci_bar_index_is_valid()
helper function uses, tidy up code comments]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: fix typo]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Hot-removal of nested PCI hotplug ports suffers from a long-standing race
condition which can lead to a deadlock: A parent hotplug port acquires
pci_lock_rescan_remove(), then waits for pciehp to unbind from a child
hotplug port. Meanwhile that child hotplug port tries to acquire
pci_lock_rescan_remove() as well in order to remove its own children.
The deadlock only occurs if the parent acquires pci_lock_rescan_remove()
first, not if the child happens to acquire it first.
Several workarounds to avoid the issue have been proposed and discarded
over the years, e.g.:
https://lore.kernel.org/r/4c882e25194ba8282b78fe963fec8faae7cf23eb.1529173804.git.lukas@wunner.de/
A proper fix is being worked on, but needs more time as it is nontrivial
and necessarily intrusive.
Recent commit 9d573d1954 ("PCI: pciehp: Detect device replacement during
system sleep") provokes more frequent occurrence of the deadlock when
removing more than one Thunderbolt device during system sleep. The commit
sought to detect device replacement, but also triggered on device removal.
Differentiating reliably between replacement and removal is impossible
because pci_get_dsn() returns 0 both if the device was removed, as well as
if it was replaced with one lacking a Device Serial Number.
Avoid the more frequent occurrence of the deadlock by checking whether the
hotplug port itself was hot-removed. If so, there's no sense in checking
whether its child device was replaced.
This works because the ->resume_noirq() callback is invoked in top-down
order for the entire hierarchy: A parent hotplug port detecting device
replacement (or removal) marks all children as removed using
pci_dev_set_disconnected() and a child hotplug port can then reliably
detect being removed.
Link: https://lore.kernel.org/r/02f166e24c87d6cde4085865cce9adfdfd969688.1741674172.git.lukas@wunner.de
Fixes: 9d573d1954 ("PCI: pciehp: Detect device replacement during system sleep")
Reported-by: Kenneth Crudup <kenny@panix.com>
Closes: https://lore.kernel.org/r/83d9302a-f743-43e4-9de2-2dd66d91ab5b@panix.com/
Reported-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Closes: https://lore.kernel.org/r/20240926125909.2362244-1-acelan.kao@canonical.com/
Tested-by: Kenneth Crudup <kenny@panix.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.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>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: stable@vger.kernel.org # v6.11+
The array for the iomapping cookie addresses has a length of
PCI_STD_NUM_BARS. This constant, however, only describes standard BARs;
while PCI can allow for additional, special BARs.
The total number of PCI resources is described by constant
PCI_NUM_RESOURCES, which is also used in, e.g., pci_select_bars().
Thus, the devres array has so far been too small.
Change the length of the devres array to PCI_NUM_RESOURCES.
Link: https://lore.kernel.org/r/20250312080634.13731-3-phasta@kernel.org
Fixes: bbaff68bf4 ("PCI: Add managed partial-BAR request and map infrastructure")
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Cc: stable@vger.kernel.org # v6.11+
Previously most resizable BAR interfaces (pci_rebar_get_possible_sizes(),
pci_rebar_set_size(), etc) as well as pci_restore_state() searched config
space for a Resizable BAR capability. Most devices don't have such a
capability, so this is wasted effort, especially for pci_restore_state().
Search for a Resizable BAR capability once at enumeration-time and cache
the offset so we don't have to search every time we need it. No functional
change intended.
Link: https://lore.kernel.org/r/20250215000301.175097-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Following a reset, a Function may respond to Config Requests with Request
Retry Status (RRS) Completion Status to indicate that it is temporarily
unable to process the Request, but will be able to process the Request in
the future (PCIe r6.0, sec 2.3.1).
If the Configuration RRS Software Visibility feature is enabled and a Root
Complex receives RRS for a config read of the Vendor ID, the Root Complex
completes the Request to the host by returning PCI_VENDOR_ID_PCI_SIG,
0x0001 (sec 2.3.2).
The Config RRS SV feature applies only to Root Ports and is not directly
related to pci_scan_bridge_extend(). Move the RRS SV enable to
set_pcie_port_type() where we handle other PCIe-specific configuration.
Link: https://lore.kernel.org/r/20250303210217.199504-1-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
pci_release_resource() will print "... releasing" regardless of the
resource being assigned or not. Move the print after the res->parent check
to avoid claiming the kernel would be releasing an unassigned resource.
Likely, none of the current callers pass a resource that is unassigned so
this change is mostly to correct the non-sensical order than to remove
errorneous printouts.
Link: https://lore.kernel.org/r/20250307140922.5776-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Per PCIe r6.0, sec 7.8.6.2, devices can advertise Resizable BAR sizes up to
128 TB in the Resizable BAR Capability register. Larger sizes can be
advertised via the Capability register, but that requires an API change.
Update pci_rebar_get_possible_sizes() and pbus_size_mem() to increase the
sizes we currently support from 512 GB to 128 TB.
Link: https://lore.kernel.org/r/20250307053535.44918-1-daizhiyuan@phytium.com.cn
Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCIe r6.1, sec 6.30.1.1, describes a "Vendor ID", a "Data Object Type" and
"Next Index" as the fields in the DOE Discovery Response Data Object. The
DOE driver currently uses both the terms 'type' and 'prot' for the second
element.
Rename all uses of the DOE Discovery Response Data Object to use 'type' as
the second element of the object header, instead of type/prot as it
currently is.
Link: https://lore.kernel.org/r/20250306075211.1855177-2-alistair@alistair23.me
Signed-off-by: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
After d88f521da3 ("PCI: Allow userspace to query and set device reset
mechanism"), userspace can disable reset of specific PCI devices by writing
an empty string to the sysfs reset_method file.
However, pci_slot_resettable() does not check pci_reset_supported(), which
means that pci_reset_function() will still reset the device even if
userspace has disabled all the reset methods.
I was able to reproduce this issue with a vfio device passed to a qemu
guest, where I had disabled PCI reset via sysfs.
Add an explicit check of pci_reset_supported() in both
pci_slot_resettable() and pci_bus_resettable() to ensure both the reset
status and reset execution are bypassed if an administrator disables it for
a device.
Link: https://lore.kernel.org/r/20250207205600.1846178-1-naravamudan@nvidia.com
Fixes: d88f521da3 ("PCI: Allow userspace to query and set device reset mechanism")
Signed-off-by: Nishanth Aravamudan <naravamudan@nvidia.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Raphael Norwitz <raphael.norwitz@nutanix.com>
Cc: Amey Narkhede <ameynarkhede03@gmail.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Yishai Hadas <yishaih@nvidia.com>
Cc: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Firmware developers reported that Linux issues two PCIe hotplug commands in
very short intervals on an ARM server, which doesn't comply with the PCIe
spec. According to PCIe r6.1, sec 6.7.3.2, if the Command Completed event
is supported, software must wait for a command to complete or wait at
least 1 second before sending a new command.
In the failure case, the first PCIe hotplug command is from
get_port_device_capability(), which sends a command to disable PCIe hotplug
interrupts without waiting for its completion, and the second command comes
from pcie_enable_notification() of pciehp driver, which enables hotplug
interrupts again.
Fix this by only disabling the hotplug interrupts when the pciehp driver is
not enabled.
Link: https://lore.kernel.org/r/20250303023630.78397-1-feng.tang@linux.alibaba.com
Fixes: 2bd50dd800 ("PCI: PCIe: Disable PCIe port services during port initialization")
Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
The PCI hotplug core contains five has_*_file() functions to determine
whether a certain sysfs file shall be added (or removed) for a given
hotplug slot.
The functions receive a struct pci_slot pointer which they have to
dereference back to a struct hotplug_slot.
Avoid by passing them a struct hotplug_slot pointer directly.
Link: https://lore.kernel.org/r/5b2f5b4ac45285953d00fd7637732a93fd40d26e.1740501868.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The PCI hotplug core contains five has_*_file() functions to determine
whether a certain sysfs file shall be added (or removed) for a given
hotplug slot.
The functions perform NULL pointer checks for the hotplug_slot and its
hotplug_slot_ops. However the callers already perform these checks:
pci_hp_register()
__pci_hp_register()
__pci_hp_initialize()
pci_hp_deregister()
pci_hp_del()
The only way to actually trigger these checks is to call pci_hp_add()
without having called pci_hp_initialize().
Amend pci_hp_add() to catch that and drop the now superfluous NULL
pointer checks in has_*_file().
Drop the same superfluous checks from pci_hp_create_module_link(),
which is (only) called from pci_hp_add().
Link: https://lore.kernel.org/r/37d1928edf8c3201a8b10794f1db3142e16e02b9.1740501868.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
In December 2002, historic commit
https://git.kernel.org/tglx/history/c/bec7aa00ffe5
("[PATCH] more module warning fixes")
amended the PCI hotplug core to acquire a reference on the hotplug
driver module when a sysfs attribute is accessed. That was necessary
because back in the day, sysfs code did not take any precautions to
prevent module unloading when an attribute was accessed.
Soon after in July 2003, historic commit
https://git.kernel.org/tglx/history/c/1cf6d20f6078
("[PATCH] SYSFS: add module referencing to sysfs attribute files.")
addressed that deficiency. But the commit neglected to remove the now
unnecessary reference acquisition from the PCI hotplug core.
The commit acquired a module reference for the entire duration between
open() and close() of a sysfs attribute. This made it impossible to
unload a module while attributes were kept open by user space.
That's possible today:
When a hotplug driver module is unloaded, it removes sysfs attributes of
all its hotplug slots by calling pci_hp_del(). This will wait for any
concurrent user space operation to finish:
pci_hp_del()
fs_remove_slot()
sysfs_remove_file()
sysfs_remove_file_ns()
kernfs_remove_by_name_ns()
__kernfs_remove()
kernfs_drain()
A user space operation such as read() briefly acquires a reference on
the attribute with kernfs_get_active(). kernfs_drain() waits until all
such references are released before allowing attribute removal. Once
the attribute is removed, any subsequent user space operation on a still
open attribute file will return -ENODEV.
Thus, reference acquisition by the PCI hotplug core is still unnecessary
today. So drop it at long last.
Link: https://lore.kernel.org/r/ed950fa2722967be4491146c7b867c1e7be11d37.1740501868.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The PCI hotplug core keeps a list of all registered slots. Its sole
purpose is to WARN() on slot removal if another slot is using the same
name.
But this can never happen because already on slot creation, an error is
returned and multiple messages are emitted if a slot's name is
duplicated:
pci_hp_register()
__pci_hp_register()
__pci_hp_initialize()
pci_create_slot()
kobject_init_and_add()
kobject_add_varg()
kobject_add_internal()
create_dir()
sysfs_create_dir_ns()
kernfs_create_dir_ns()
sysfs_warn_dup()
pr_warn("cannot create duplicate filename ...")
pr_err("%s failed for %s with -EEXIST, ...");
Drop the superfluous list.
Link: https://lore.kernel.org/r/603735bc50eb370bc7f1c358441ac671360bab25.1740501868.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The test shell script "set_pcie_speed.sh" is not installed in INSTALL_PATH.
Attempting to execute set_pcie_cooling_state.sh shows warning:
./set_pcie_cooling_state.sh: line 119: ./set_pcie_speed.sh: No such file or directory
Add "set_pcie_speed.sh" to TEST_PROGS.
Link: https://lore.kernel.org/r/Z8FfK8rN30lKzvVV@ly-workstation
Fixes: 838f12c3d5 ("selftests/pcie_bwctrl: Create selftests")
Signed-off-by: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Log pci_dbg() messages about the reset methods we attempt and any errors
(-ENOTTY means "try the next method").
Set CONFIG_DYNAMIC_DEBUG=y and enable by booting with
dyndbg="file drivers/pci/* +p" or enable at runtime:
# echo "file drivers/pci/* +p" > /sys/kernel/debug/dynamic_debug/control
Link: https://lore.kernel.org/r/20250303204220.197172-1-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
PCI devices device tree nodes can be already created. This was introduced
by commit 407d1a5192 ("PCI: Create device tree node for bridge").
In order to have device tree nodes related to PCI devices attached on their
PCI root bus (the PCI bus handled by the PCI host bridge), a PCI root bus
device tree node is needed. This root bus node will be used as the parent
node of the first level devices scanned on the bus. On device tree based
systems, this PCI root bus device tree node is set to the node of the
related PCI host bridge. The PCI host bridge node is available in the
device tree used to describe the hardware passed at boot.
On non device tree based system (such as ACPI), a device tree node for the
PCI host bridge or for the root bus does not exist. Indeed, the PCI host
bridge is not described in a device tree used at boot simply because no
device tree is passed at boot.
The device tree PCI host bridge node creation needs to be done at runtime.
This is done in the same way as for the creation of the PCI device nodes.
I.e. node and properties are created based on computed information done by
the PCI core. Also, as is done on device tree based systems, this PCI host
bridge node is used for the PCI root bus.
With this done, hardware available in a PCI device that doesn't follow the
PCI model consisting in one PCI function handled by one driver can be
described by a device tree overlay loaded by the PCI device driver on non
device tree based systems. Those PCI devices provide a single PCI function
that includes several functionalities that require different drivers. The
device tree overlay describes the internal devices and their relationships.
It allows to load drivers needed by those different devices in order to
have functionalities handled.
Link: https://lore.kernel.org/r/20250224141356.36325-6-herve.codina@bootlin.com
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
