- 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 devices (not CXL) can support DOE as well, so allow DOE to be enabled
even if CXL isn't.
Link: https://lore.kernel.org/r/20250306075211.1855177-4-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>
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>
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>
Currently, pci_bridge_d3_possible() encodes a variety of decision factors
when deciding whether a given bridge can be put into D3. A particular one
of note is for "recent enough PCIe ports." Per Rafael [0]:
"There were hardware issues related to PM on x86 platforms predating
the introduction of Connected Standby in Windows. For instance,
programming a port into D3hot by writing to its PMCSR might cause the
PCIe link behind it to go down and the only way to revive it was to
power cycle the Root Complex. And similar."
Thus, this function contains a DMI-based check for post-2015 BIOS.
The above factors (Windows, x86) don't really apply to non-x86 systems, and
also, many such systems don't have BIOS or DMI. However, we'd like to be
able to suspend bridges on non-x86 systems too.
Restrict the "recent enough" check to x86. If we find further
incompatibilities, it probably makes sense to expand on the deny-list
approach (i.e., bridge_d3_blacklist or similar).
Link: https://lore.kernel.org/r/20250320110604.v6.1.Id0a0e78ab0421b6bce51c4b0b87e6aebdfc69ec7@changeid
Link: https://lore.kernel.org/linux-pci/CAJZ5v0j_6jeMAQ7eFkZBe5Yi+USGzysxAgfemYh=-zq4h5W+Qg@mail.gmail.com/ [0]
Link: https://lore.kernel.org/linux-pci/20240227225442.GA249898@bhelgaas/ [1]
Link: https://lore.kernel.org/linux-pci/20240828210705.GA37859@bhelgaas/ [2]
[Brian: rewrite to !X86 based on Rafael's suggestions]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.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+
This put_device() was accidentally left over from when we changed the code
from using device_register() to calling device_add(). Delete it.
Link: https://lore.kernel.org/r/55b24870-89fb-4c91-b85d-744e35db53c2@stanley.mountain
Fixes: 9885440b16 ("PCI: Fix pci_host_bridge struct device release/free handling")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
If device_register(&child->dev) fails, call put_device() to explicitly
release child->dev, per the comment at device_register().
Found by code review.
Link: https://lore.kernel.org/r/20250202062357.872971-1-make24@iscas.ac.cn
Fixes: 4f535093cf ("PCI: Put pci_dev in device tree as early as possible")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: stable@vger.kernel.org
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>
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>
DOE r1.1 replaced all occurrences of "protocol" with the term "feature" or
"Data Object Type". PCIe r6.1 incorporated that change.
Rename the existing terms protocol with feature.
Link: https://lore.kernel.org/r/20250306075211.1855177-1-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>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
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>
For no apparent reason, the pci_hp_{create,remove}_module_link() helpers
live in slot.c, even though they're only called from two functions in
pci_hotplug_core.c.
Inline the helpers to reduce code size and number of exported symbols.
Link: https://lore.kernel.org/r/c207f03cfe32ae9002d9b453001a1dd63d9ab3fb.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 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>
The .get_power() and .set_power() function pointers in struct
cpci_hp_controller_ops were declared but never implemented by any
driver.
Thus, to improve code readability and reduce resource usage,
remove these pointers and the code that has never been used.
Link: https://lore.kernel.org/r/20250217185638.398925-1-trintaeoitogc@gmail.com
Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Flit mode introduced in PCIe r6.0 alters how the TLP Header Log is
presented through AER and DPC Capability registers. The TLP Prefix Log
Register is not present with Flit mode, and the register becomes an
extension of the TLP Header Log (PCIe r6.1 secs 7.8.4.12 & 7.9.14.13).
Adapt pcie_read_tlp_log() and struct pcie_tlp_log to read and store the
extended TLP Header Log when the Link is in Flit mode. As the Prefix Log
and Extended TLP Header are not present at the same time, a C union can be
used.
Determining whether the error occurred while the Link was in Flit mode is a
bit complicated. In case of AER, the Advanced Error Capabilities and
Control Register directly tells whether the error was logged in Flit mode
or not (PCIe r6.1 sec 7.8.4.7). The DPC Capability (PCIe r6.1 sec 7.9.14),
unfortunately, does not contain the same information.
Unlike AER, the DPC Capability does not provide a way to discern whether
the error was logged in Flit mode (this is confirmed by PCI WG to be an
oversight in the spec). DPC will bring the Link down immediately following
an error, which makes it impossible to acquire the Flit Mode Status
directly from the Link Status 2 register because Flit Mode Status is only
set in certain Link states (PCIe r6.1 sec 7.5.3.20). As a workaround, use
the flit_mode value stored into the struct pci_bus.
Link: https://lore.kernel.org/r/20250207161836.2755-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
PCIe r6.0 added Flit mode, which mainly alters HW behavior, but there are
some OS visible changes. The OS visible changes include differences in the
layout of some capabilities and interpretation of the TLP headers (in
diagnostics situations).
To be able to determine which mode the PCIe Link is using, store the Flit
Mode Status (PCIe r6.1 sec 7.5.3.20) information in addition to the Link
speed into struct pci_bus in pcie_update_link_speed().
Link: https://lore.kernel.org/r/20250207161836.2755-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: use unsigned int:1 instead of bool, update flit_mode setting]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
include/linux/pci.h provides low-level pci_printk() interface that is
only used by AER because it needs to print the same message with
different levels depending on the error severity. No other PCI code
uses that functionality and calls pci_<level>() logging functions
directly with the appropriate level.
Descope pci_printk() into AER as aer_printk().
Link: https://lore.kernel.org/r/20241216161012.1774-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: retain pci_printk() for now since shpchp still uses it and I
moved those patches to a different branch]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This driver is used to control the power state of the devices attached to
the PCI slots. Currently, it controls the voltage rails of the PCI slots
defined in the devicetree node of the root port.
The voltage rails for PCI slots are documented in the DT-schema:
https://github.com/devicetree-org/dt-schema/blob/v2024.11/dtschema/schemas/pci/pci-bus-common.yaml#L153
Since this driver has to work with different kind of slots (PCIe
x1/x4/x8/x16, Mini PCIe, PCI, etc.), the driver is thus using the
of_regulator_bulk_get_all() API to obtain the voltage regulators defined
in the DT node, instead of hardcoding them.
As such, the DT node of the root port should define the relevant supply
properties corresponding to the voltage rails of the PCI slot.
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-5-827473c8fbf4@linaro.org
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
The "pciclass" is an existing prefix used to identify the PCI bridge
devices, but it is not a vendor prefix. So document it in the non-vendor
prefix list.
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-4-827473c8fbf4@linaro.org
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
The pwrctrl core will rescan the bus once the device is powered on. So
there is no need to continue scanning for the device further.
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-3-827473c8fbf4@linaro.org
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
The PCI core will try to access the devices even after pci_stop_dev()
for things like Data Object Exchange (DOE), ASPM, etc.
So, move pci_pwrctrl_unregister() to the near end of pci_destroy_dev()
to make sure that the devices are powered down only after the PCI core
is done with them.
Suggested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-2-827473c8fbf4@linaro.org
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Current way of creating pwrctrl devices requires iterating through the
child devicetree nodes of the PCI bridge in pci_pwrctrl_create_devices().
Even though it works, it creates confusion as there is no symmetry between
this and pci_pwrctrl_unregister() function that removes the pwrctrl
devices.
So to make these two functions symmetric, move the creation of pwrctrl
devices to pci_scan_device(). During the scan of each device in a slot,
the devicetree node (if exists) for the PCI device will be checked. If it
has the supplies populated, then the pwrctrl device will be created.
Since the PCI device scan happens so early, there would be no "struct
pci_dev" available for the device. So the host bridge is used as the
parent of all pwrctrl devices.
One nice side effect of this move is that, it is now possible to have
pwrctrl devices for PCI bridges as well (to control the supplies of PCI
slots).
Suggested-by: Lukas Wunner <lukas@wunner.de>
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250116-pci-pwrctrl-slot-v3-1-827473c8fbf4@linaro.org
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Before 456d8aa37d ("PCI/ASPM: Disable ASPM on MFD function removal to
avoid use-after-free"), we would free the ASPM link only after the last
function on the bus pertaining to the given link was removed.
That was too late. If function 0 is removed before sibling function,
link->downstream would point to free'd memory after.
After above change, we freed the ASPM parent link state upon any function
removal on the bus pertaining to a given link.
That is too early. If the link is to a PCIe switch with MFD on the upstream
port, then removing functions other than 0 first would free a link which
still remains parent_link to the remaining downstream ports.
The resulting GPFs are especially frequent during hot-unplug, because
pciehp removes devices on the link bus in reverse order.
On that switch, function 0 is the virtual P2P bridge to the internal bus.
Free exactly when function 0 is removed -- before the parent link is
obsolete, but after all subordinate links are gone.
Link: https://lore.kernel.org/r/e12898835f25234561c9d7de4435590d957b85d9.1734924854.git.dns@arista.com
Fixes: 456d8aa37d ("PCI/ASPM: Disable ASPM on MFD function removal to avoid use-after-free")
Signed-off-by: Daniel Stodden <dns@arista.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
The "shpchp_debug" module parameter is used to enable debug logging. The
generic ability to turn on/off debug prints dynamically covers this use
case already so there is no need for module specific debug handling. The
ctrl_dbg() wrapper also uses a low-level pci_printk() despite always using
KERN_DEBUG level.
Remove "shpchp_debug" parameter and convert ctrl_dbg() to use pci_dbg().
From now on, shpchp can be debugged using the normal dynamic debugger by
setting CONFIG_DYNAMIC_DEBUG=y and then either adding to kernel cmdline:
dyndbg="file drivers/pci/hotplug/shpchp* +p"
or using this command on a running kernel:
echo 'file drivers/pci/hotplug/shpchp* +p' > /sys/kernel/debug/dynamic_debug/control
Link: https://lore.kernel.org/r/20250217095550.2789-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The shpchp hotplug driver defines logging wrapper with generic names which
are just duplicates of existing generic printk() wrappers. They are also
unused so remove them.
Link: https://lore.kernel.org/r/20250217095550.2789-2-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Fix regression in 2023.11.07 that affinitized forked child
in one-shot mode.
Harden one-shot mode against hotplug online/offline
Enable RAPL SysWatt column by default.
Add initial PTL, CWF platform support.
Harden initial PMT code in response to early use.
Enable first built-in PMT counter: CWF c1e residency
Refuse to run on unsupported platforms without --force,
to encourage updating to a version that supports the system,
and to avoid no-so-useful measurement results.
-----BEGIN PGP SIGNATURE-----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=mWV6
-----END PGP SIGNATURE-----
Merge tag 'turbostat-2025.02.02' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
Pull turbostat updates from Len Brown:
- Fix regression that affinitized forked child in one-shot mode.
- Harden one-shot mode against hotplug online/offline
- Enable RAPL SysWatt column by default
- Add initial PTL, CWF platform support
- Harden initial PMT code in response to early use
- Enable first built-in PMT counter: CWF c1e residency
- Refuse to run on unsupported platforms without --force, to encourage
updating to a version that supports the system, and to avoid
no-so-useful measurement results
* tag 'turbostat-2025.02.02' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: (25 commits)
tools/power turbostat: version 2025.02.02
tools/power turbostat: Add CPU%c1e BIC for CWF
tools/power turbostat: Harden one-shot mode against cpu offline
tools/power turbostat: Fix forked child affinity regression
tools/power turbostat: Add tcore clock PMT type
tools/power turbostat: version 2025.01.14
tools/power turbostat: Allow adding PMT counters directly by sysfs path
tools/power turbostat: Allow mapping multiple PMT files with the same GUID
tools/power turbostat: Add PMT directory iterator helper
tools/power turbostat: Extend PMT identification with a sequence number
tools/power turbostat: Return default value for unmapped PMT domains
tools/power turbostat: Check for non-zero value when MSR probing
tools/power turbostat: Enhance turbostat self-performance visibility
tools/power turbostat: Add fixed RAPL PSYS divisor for SPR
tools/power turbostat: Fix PMT mmaped file size rounding
tools/power turbostat: Remove SysWatt from DISABLED_BY_DEFAULT
tools/power turbostat: Add an NMI column
tools/power turbostat: add Busy% to "show idle"
tools/power turbostat: Introduce --force parameter
tools/power turbostat: Improve --help output
...
