<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/pci/bus.c, branch v7.1</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v7.1</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v7.1'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-02-22T01:09:51+00:00</updated>
<entry>
<title>Convert 'alloc_obj' family to use the new default GFP_KERNEL argument</title>
<updated>2026-02-22T01:09:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-02-22T00:37:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43'/>
<id>urn:sha1:bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43</id>
<content type='text'>
This was done entirely with mindless brute force, using

    git grep -l '\&lt;k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>treewide: Replace kmalloc with kmalloc_obj for non-scalar types</title>
<updated>2026-02-21T09:02:28+00:00</updated>
<author>
<name>Kees Cook</name>
<email>kees@kernel.org</email>
</author>
<published>2026-02-21T07:49:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=69050f8d6d075dc01af7a5f2f550a8067510366f'/>
<id>urn:sha1:69050f8d6d075dc01af7a5f2f550a8067510366f</id>
<content type='text'>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook &lt;kees@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge branch 'pci/pwrctrl'</title>
<updated>2026-02-06T23:09:24+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2026-02-06T23:09:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=bf37448d9b7793544904ccf21e5844b6ff4af3c0'/>
<id>urn:sha1:bf37448d9b7793544904ccf21e5844b6ff4af3c0</id>
<content type='text'>
- Rename pwrseq, tc9563, and slot driver structs, variables, and functions
  for consistency (Bjorn Helgaas)

- Add power_on/off callbacks with generic signature to pwrseq, tc9563, and
  slot drivers so they can be used by pwrctrl core (Manivannan Sadhasivam)

- Add interfaces to create and destroy pwrctrl devices (Krishna Chaitanya
  Chundru)

- Add interfaces to power devices on and off (Manivannan Sadhasivam)

- Switch to pwrctrl interfaces to create, destroy, and power on/off
  devices, calling them from host controller drivers instead of the PCI
  core (Manivannan Sadhasivam)

- Drop qcom .assert_perst() callbacks since this is now done by the
  controller driver instead of the pwrctrl driver (Manivannan Sadhasivam)

- Add PCIe M.2 connector support to the slot pwrctrl driver (Manivannan
  Sadhasivam)

- Create pwrctrl devices for devicetree PCIe M.2 connector nodes
  (Manivannan Sadhasivam)

* pci/pwrctrl:
  PCI/pwrctrl: Create pwrctrl device if graph port is found
  PCI/pwrctrl: Add PCIe M.2 connector support
  PCI: Drop the assert_perst() callback
  PCI: qcom: Drop the assert_perst() callbacks
  PCI/pwrctrl: Switch to pwrctrl create, power on/off, destroy APIs
  PCI/pwrctrl: Add APIs to power on/off pwrctrl devices
  PCI/pwrctrl: Add APIs to create, destroy pwrctrl devices
  PCI/pwrctrl: Add 'struct pci_pwrctrl::power_{on/off}' callbacks
  PCI/pwrctrl: pwrseq: Factor out power on/off code to helpers
  PCI/pwrctrl: slot: Factor out power on/off code to helpers
  PCI/pwrctrl: tc9563: Rename private struct and pointers for consistency
  PCI/pwrctrl: tc9563: Add local variables to reduce repetition
  PCI/pwrctrl: tc9563: Clean up whitespace
  PCI/pwrctrl: tc9563: Use put_device() instead of i2c_put_adapter()
  PCI/pwrctrl: slot: Rename private struct and pointers for consistency
  PCI/pwrctrl: pwrseq: Rename private struct and pointers for consistency

# Conflicts:
#	drivers/pci/bus.c
</content>
</entry>
<entry>
<title>PCI/PM: Prevent runtime suspend until devices are fully initialized</title>
<updated>2026-01-22T19:02:55+00:00</updated>
<author>
<name>Brian Norris</name>
<email>briannorris@chromium.org</email>
</author>
<published>2026-01-22T17:48:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=51c0996dadaea20d73eb0495aeda9cb0422243e8'/>
<id>urn:sha1:51c0996dadaea20d73eb0495aeda9cb0422243e8</id>
<content type='text'>
Previously, it was possible for a PCI device to be runtime-suspended before
it was fully initialized. When that happened, the suspend process could
save invalid device state, for example, before BAR assignment. Restoring
the invalid state during resume may leave the device non-functional.

Prevent runtime suspend for PCI devices until they are fully initialized by
deferring pm_runtime_enable().

More details on how exactly this may occur:

  1. PCI device is created by pci_scan_slot() or similar

  2. As part of pci_scan_slot(), pci_pm_init() puts the device in D0 and
     prevents runtime suspend prevented via pm_runtime_forbid()

  3. pci_device_add() adds the underlying 'struct device' via device_add(),
     which means user space can allow runtime suspend, e.g.,

       echo auto &gt; /sys/bus/pci/devices/.../power/control

  4. PCI device receives BAR configuration
     (pci_assign_unassigned_bus_resources(), etc.)

  5. pci_bus_add_device() applies final fixups, saves device state, and
     tries to attach a driver

The device may potentially be suspended between #3 and #5, so this is racy
with user space (udev or similar).

Many PCI devices are enumerated at subsys_initcall time and so will not
race with user space, but devices created later by hotplug or modular
pwrctrl or host controller drivers are susceptible to this race.

More runtime PM details at the first Link: below.

Link: https://lore.kernel.org/all/0e35a4e1-894a-47c1-9528-fc5ffbafd9e2@samsung.com/
Signed-off-by: Brian Norris &lt;briannorris@chromium.org&gt;
[bhelgaas: update comments per https://lore.kernel.org/r/CAJZ5v0iBNOmMtqfqEbrYyuK2u+2J2+zZ-iQd1FvyCPjdvU2TJg@mail.gmail.com]
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Tested-by: Marek Szyprowski &lt;m.szyprowski@samsung.com&gt;
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260122094815.v5.1.I60a53c170a8596661883bd2b4ef475155c7aa72b@changeid
</content>
</entry>
<entry>
<title>PCI/pwrctrl: Switch to pwrctrl create, power on/off, destroy APIs</title>
<updated>2026-01-16T19:23:38+00:00</updated>
<author>
<name>Manivannan Sadhasivam</name>
<email>manivannan.sadhasivam@oss.qualcomm.com</email>
</author>
<published>2026-01-15T07:29:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=b921aa3f8decae440009134d65399ee9b2425300'/>
<id>urn:sha1:b921aa3f8decae440009134d65399ee9b2425300</id>
<content type='text'>
Adopt pwrctrl APIs to create, power on/off, and destroy pwrctrl devices.

In qcom_pcie_host_init(), call pci_pwrctrl_create_devices() to create
devices, then pci_pwrctrl_power_on_devices() to power them on, both after
controller resource initialization. Once successful, deassert PERST# for
all devices.

In qcom_pcie_host_deinit(), call pci_pwrctrl_power_off_devices() after
asserting PERST#. Note that pci_pwrctrl_destroy_devices() is not called
here, as deinit is only invoked during system suspend where device
destruction is unnecessary. If the driver becomes removable in future,
pci_pwrctrl_destroy_devices() should be called in the remove() handler.

Remove the old pwrctrl framework code from the PCI core (including
devlinks) as the new APIs are now the sole consumer of pwrctrl
functionality. And also do not power on the pwrctrl drivers during probe()
as this is now handled by the APIs.

Co-developed-by: Krishna Chaitanya Chundru &lt;krishna.chundru@oss.qualcomm.com&gt;
Signed-off-by: Krishna Chaitanya Chundru &lt;krishna.chundru@oss.qualcomm.com&gt;
Signed-off-by: Manivannan Sadhasivam &lt;manivannan.sadhasivam@oss.qualcomm.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Tested-by: Chen-Yu Tsai &lt;wenst@chromium.org&gt;
Reviewed-by: Bartosz Golaszewski &lt;bartosz.golaszewski@oss.qualcomm.com&gt;
Link: https://patch.msgid.link/20260115-pci-pwrctrl-rework-v5-12-9d26da3ce903@oss.qualcomm.com
</content>
</entry>
<entry>
<title>Merge tag 'tsm-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm</title>
<updated>2025-12-06T18:15:41+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-12-06T18:15:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=249872f53d64441690927853e9d3af36394802d5'/>
<id>urn:sha1:249872f53d64441690927853e9d3af36394802d5</id>
<content type='text'>
Pull PCIe Link Encryption and Device Authentication from Dan Williams:
 "New PCI infrastructure and one architecture implementation for PCIe
  link encryption establishment via platform firmware services.

  This work is the result of multiple vendors coming to consensus on
  some core infrastructure (thanks Alexey, Yilun, and Aneesh!), and
  three vendor implementations, although only one is included in this
  pull. The PCI core changes have an ack from Bjorn, the crypto/ccp/
  changes have an ack from Tom, and the iommu/amd/ changes have an ack
  from Joerg.

  PCIe link encryption is made possible by the soup of acronyms
  mentioned in the shortlog below. Link Integrity and Data Encryption
  (IDE) is a protocol for installing keys in the transmitter and
  receiver at each end of a link. That protocol is transported over Data
  Object Exchange (DOE) mailboxes using PCI configuration requests.

  The aspect that makes this a "platform firmware service" is that the
  key provisioning and protocol is coordinated through a Trusted
  Execution Envrionment (TEE) Security Manager (TSM). That is either
  firmware running in a coprocessor (AMD SEV-TIO), or quasi-hypervisor
  software (Intel TDX Connect / ARM CCA) running in a protected CPU
  mode.

  Now, the only reason to ask a TSM to run this protocol and install the
  keys rather than have a Linux driver do the same is so that later, a
  confidential VM can ask the TSM directly "can you certify this
  device?".

  That precludes host Linux from provisioning its own keys, because host
  Linux is outside the trust domain for the VM. It also turns out that
  all architectures, save for one, do not publish a mechanism for an OS
  to establish keys in the root port. So "TSM-established link
  encryption" is the only cross-architecture path for this capability
  for the foreseeable future.

  This unblocks the other arch implementations to follow in v6.20/v7.0,
  once they clear some other dependencies, and it unblocks the next
  phase of work to implement the end-to-end flow of confidential device
  assignment. The PCIe specification calls this end-to-end flow Trusted
  Execution Environment (TEE) Device Interface Security Protocol
  (TDISP).

  In the meantime, Linux gets a link encryption facility which has
  practical benefits along the same lines as memory encryption. It
  authenticates devices via certificates and may protect against
  interposer attacks trying to capture clear-text PCIe traffic.

  Summary:

   - Introduce the PCI/TSM core for the coordination of device
     authentication, link encryption and establishment (IDE), and later
     management of the device security operational states (TDISP).
     Notify the new TSM core layer of PCI device arrival and departure

   - Add a low level TSM driver for the link encryption establishment
     capabilities of the AMD SEV-TIO architecture

   - Add a library of helpers TSM drivers to use for IDE establishment
     and the DOE transport

   - Add skeleton support for 'bind' and 'guest_request' operations in
     support of TDISP"

* tag 'tsm-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/devsec/tsm: (23 commits)
  crypto/ccp: Fix CONFIG_PCI=n build
  virt: Fix Kconfig warning when selecting TSM without VIRT_DRIVERS
  crypto/ccp: Implement SEV-TIO PCIe IDE (phase1)
  iommu/amd: Report SEV-TIO support
  psp-sev: Assign numbers to all status codes and add new
  ccp: Make snp_reclaim_pages and __sev_do_cmd_locked public
  PCI/TSM: Add 'dsm' and 'bound' attributes for dependent functions
  PCI/TSM: Add pci_tsm_guest_req() for managing TDIs
  PCI/TSM: Add pci_tsm_bind() helper for instantiating TDIs
  PCI/IDE: Initialize an ID for all IDE streams
  PCI/IDE: Add Address Association Register setup for downstream MMIO
  resource: Introduce resource_assigned() for discerning active resources
  PCI/TSM: Drop stub for pci_tsm_doe_transfer()
  drivers/virt: Drop VIRT_DRIVERS build dependency
  PCI/TSM: Report active IDE streams
  PCI/IDE: Report available IDE streams
  PCI/IDE: Add IDE establishment helpers
  PCI: Establish document for PCI host bridge sysfs attributes
  PCI: Add PCIe Device 3 Extended Capability enumeration
  PCI/TSM: Establish Secure Sessions and Link Encryption
  ...
</content>
</entry>
<entry>
<title>PCI/ERR: Ensure error recoverability at all times</title>
<updated>2025-11-24T22:58:33+00:00</updated>
<author>
<name>Lukas Wunner</name>
<email>lukas@wunner.de</email>
</author>
<published>2025-11-19T08:50:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a2f1e22390ac2ca7ac8d77aa0f78c068b6dd2208'/>
<id>urn:sha1:a2f1e22390ac2ca7ac8d77aa0f78c068b6dd2208</id>
<content type='text'>
When the PCI core gained power management support in 2002, it introduced
pci_save_state() and pci_restore_state() helpers to restore Config Space
after a D3hot or D3cold transition, which implies a Soft or Fundamental
Reset (PCIe r7.0 sec 5.8):

  https://git.kernel.org/tglx/history/c/a5287abe398b

In 2006, EEH and AER were introduced to recover from errors by performing
a reset.  Because errors can occur at any time, drivers began calling
pci_save_state() on probe to ensure recoverability.

In 2009, recoverability was foiled by commit c82f63e411f1 ("PCI: check
saved state before restore"):  It amended pci_restore_state() to bail out
if the "state_saved" flag has been cleared.  The flag is cleared by
pci_restore_state() itself, hence a saved state is now allowed to be
restored only once and is then invalidated.  That doesn't seem to make
sense because the saved state should be good enough to be reused.

Soon after, drivers began to work around this behavior by calling
pci_save_state() immediately after pci_restore_state(), see e.g. commit
b94f2d775a71 ("igb: call pci_save_state after pci_restore_state").
Hilariously, two drivers even set the "saved_state" flag to true before
invoking pci_restore_state(), see ipr_reset_restore_cfg_space() and
e1000_io_slot_reset().

Despite these workarounds, recoverability at all times is not guaranteed:
E.g. when a PCIe port goes through a runtime suspend and resume cycle,
the "saved_state" flag is cleared by:

  pci_pm_runtime_resume()
    pci_pm_default_resume_early()
      pci_restore_state()

... and hence on a subsequent AER event, the port's Config Space cannot be
restored.  Riana reports a recovery failure of a GPU-integrated PCIe
switch and has root-caused it to the behavior of pci_restore_state().
Another workaround would be necessary, namely calling pci_save_state() in
pcie_port_device_runtime_resume().

The motivation of commit c82f63e411f1 was to prevent restoring state if
pci_save_state() hasn't been called before.  But that can be achieved by
saving state already on device addition, after Config Space has been
initialized.  A desirable side effect is that devices become recoverable
even if no driver gets bound.  This renders the commit unnecessary, so
revert it.

Reported-by: Riana Tauro &lt;riana.tauro@intel.com&gt; # off-list
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Tested-by: Riana Tauro &lt;riana.tauro@intel.com&gt;
Reviewed-by: Rafael J. Wysocki (Intel) &lt;rafael@kernel.org&gt;
Link: https://patch.msgid.link/9e34ce61c5404e99ffdd29205122c6fb334b38aa.1763483367.git.lukas@wunner.de
</content>
</entry>
<entry>
<title>PCI: Introduce pci_walk_bus_reverse(), for_each_pci_dev_reverse()</title>
<updated>2025-11-04T03:27:40+00:00</updated>
<author>
<name>Dan Williams</name>
<email>dan.j.williams@intel.com</email>
</author>
<published>2025-10-31T21:28:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=215afa89d249bb095126cf00f8be719e421c75e9'/>
<id>urn:sha1:215afa89d249bb095126cf00f8be719e421c75e9</id>
<content type='text'>
PCI/TSM, the PCI core functionality for the PCIe TEE Device Interface
Security Protocol (TDISP), has a need to walk all subordinate functions of
a Device Security Manager (DSM) to setup a device security context. A DSM
is physical function 0 of multi-function or SR-IOV device endpoint, or it
is an upstream switch port.

In error scenarios or when a TEE Security Manager (TSM) device is removed
it needs to unwind all established DSM contexts.

Introduce reverse versions of PCI device iteration helpers to mirror the
setup path and ensure that dependent children are handled before parents.

Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Jonathan Cameron &lt;jonathan.cameron@huawei.com&gt;
Link: https://patch.msgid.link/20251031212902.2256310-4-dan.j.williams@intel.com
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</content>
</entry>
<entry>
<title>Merge branch 'pci/resource'</title>
<updated>2025-10-03T17:13:12+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2025-10-03T17:13:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=fead6a0b15bf3b33dba877efec6b4e7b4cc4abc3'/>
<id>urn:sha1:fead6a0b15bf3b33dba877efec6b4e7b4cc4abc3</id>
<content type='text'>
- Ensure relaxed tail alignment does not increase min_align when computing
  bridge window size, to fix a regression (Ilpo Järvinen)

- Fix bridge window size computation to fix a regression for devices with
  undefined PCI class, e.g., Samsung [144d:a5a5] (Ilpo Järvinen)

- Fix error handling during resource resize to fix a regression in amdgpu
  (Ilpo Järvinen)

- Align m68k pcibios_enable_device() with other arches (Ilpo Järvinen)

- Remove several sparc pcibios_enable_device() implementations that don't
  do anything beyond what pci_enable_resources() does (Ilpo Järvinen)

- Remove mips pcibios_enable_resources() and use pci_enable_resources()
  instead (Ilpo Järvinen)

- Refactor and simplify find_bus_resource_of_type() (Ilpo Järvinen)

- Claim bridge windows before setting them up (Ilpo Järvinen)

- Disable non-claimed bridge windows so the kernel's view matches the
  hardware configuration (Ilpo Järvinen)

- Use pci_release_resource() instead of release_resource() to reduce code
  duplication and increase consistency (Ilpo Järvinen)

- Enable bridges even if bridge window assignment fails (Ilpo Järvinen)

- Preserve bridge window resource type flags when assignment fails because
  we may need it later (Ilpo Järvinen)

- Add bridge window selection functions to make the selection consistent
  across the several places that do this (Ilpo Järvinen)

- Warn if bridge window cannot be released when resizing BAR (Ilpo
  Järvinen)

- Set up bridge resources before enumerating children so we can check
  whether child resources are inside bridge windows (Ilpo Järvinen)

* pci/resource:
  PCI: Set up bridge resources earlier
  PCI: Don't print stale information about resource
  PCI: Alter misleading recursion to pci_bus_release_bridge_resources()
  PCI: Pass bridge window to pci_bus_release_bridge_resources()
  PCI: Add pci_setup_one_bridge_window()
  PCI: Refactor remove_dev_resources() to use pbus_select_window()
  PCI: Refactor distributing available memory to use loops
  PCI: Use pbus_select_window_for_type() during mem window sizing
  PCI: Use pbus_select_window() in space available checker
  PCI: Rename resource variable from r to res
  PCI: Use pbus_select_window_for_type() during IO window sizing
  PCI: Use pbus_select_window() during BAR resize
  PCI: Warn if bridge window cannot be released when resizing BAR
  PCI: Fix finding bridge window in pci_reassign_bridge_resources()
  PCI: Add bridge window selection functions
  PCI: Add defines for bridge window indexing
  PCI: Preserve bridge window resource type flags
  PCI: Enable bridge even if bridge window fails to assign
  PCI: Use pci_release_resource() instead of release_resource()
  PCI: Disable non-claimed bridge window
  PCI: Always claim bridge window before its setup
  PCI: Refactor find_bus_resource_of_type() logic checks
  PCI: Move find_bus_resource_of_type() earlier
  MIPS: PCI: Use pci_enable_resources()
  sparc/PCI: Remove pcibios_enable_device() as they do nothing extra
  m68k/PCI: Use pci_enable_resources() in pcibios_enable_device()
  PCI: Fix failure detection during resource resize
  PCI: Fix pdev_resources_assignable() disparity
  PCI: Ensure relaxed tail alignment does not increase min_align
</content>
</entry>
<entry>
<title>PCI: Preserve bridge window resource type flags</title>
<updated>2025-09-16T16:19:18+00:00</updated>
<author>
<name>Ilpo Järvinen</name>
<email>ilpo.jarvinen@linux.intel.com</email>
</author>
<published>2025-08-29T13:10:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8278c6914306f35f32d73bdf2a918950919a0051'/>
<id>urn:sha1:8278c6914306f35f32d73bdf2a918950919a0051</id>
<content type='text'>
When a bridge window is found unused or fails to assign, the flags of the
associated resource are cleared. Clearing flags is problematic as it also
removes the type information of the resource which is needed later.

Thus, always preserve the bridge window type flags and use IORESOURCE_UNSET
and IORESOURCE_DISABLED to indicate the status of the bridge window. Also,
when initializing resources, make sure all valid bridge windows do get
their type flags set.

Change various places that relied on resource flags being cleared to check
for IORESOURCE_UNSET and IORESOURCE_DISABLED to allow bridge window
resource to retain their type flags. Add pdev_resource_assignable() and
pdev_resource_should_fit() helpers to filter out disabled bridge windows
during resource fitting; the latter combines more common checks into the
helper.

When reading the bridge windows from the registers, instead of leaving the
resource flags cleared for bridge windows that are not enabled, always
set up the flags and set IORESOURCE_UNSET | IORESOURCE_DISABLED as needed.

When resource fitting or assignment fails for a bridge window resource, or
the bridge window is not needed, mark the resource with IORESOURCE_UNSET or
IORESOURCE_DISABLED, respectively.

Use dummy zero resource in resource_show() for backwards compatibility as
lspci will otherwise misrepresent disabled bridge windows.

This change fixes an issue which highlights the importance of keeping the
resource type flags intact:

  At the end of __assign_resources_sorted(), reset_resource() is called,
  previously clearing the flags. Later, pci_prepare_next_assign_round()
  attempted to release bridge resources using
  pci_bus_release_bridge_resources() that calls into
  pci_bridge_release_resources() that assumes type flags are still present.
  As type flags were cleared, IORESOURCE_MEM_64 was not set leading to
  resources under an incorrect bridge window to be released (idx = 1
  instead of idx = 2). While the assignments performed later covered this
  problem so that the wrongly released resources got assigned in the end,
  it was still causing extra release+assign pairs.

There are other reasons why the resource flags should be retained in
upcoming changes too.

Removing the flag reset for non-bridge window resource is left as future
work, in part because it has a much higher regression potential due to
pci_enable_resources() that will start to work also for those resources
then and due to what endpoint drivers might assume about resources.

Despite the Fixes tag, backporting this (at least any time soon) is highly
discouraged. The issue fixed is borderline cosmetic as the later
assignments normally cover the problem entirely. Also there might be
non-obvious dependencies.

Fixes: 5b28541552ef ("PCI: Restrict 64-bit prefetchable bridge windows to 64-bit resources")
Signed-off-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Link: https://patch.msgid.link/20250829131113.36754-11-ilpo.jarvinen@linux.intel.com
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