<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/drivers/pci/Kconfig, branch linux-6.16.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-6.16.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-6.16.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2025-04-23T20:40:30Z</updated>
<entry>
<title>PCI: Add CONFIG_MMU dependency</title>
<updated>2025-04-23T20:40:30Z</updated>
<author>
<name>Arnd Bergmann</name>
</author>
<published>2025-04-23T20:16:32Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=8fe743b5eba0abfbee39fe27b12acfb0df9b8a2d'/>
<id>urn:sha1:8fe743b5eba0abfbee39fe27b12acfb0df9b8a2d</id>
<content type='text'>
It turns out that there are no platforms that have PCI but don't have an
MMU, so adding a Kconfig dependency on CONFIG_PCI simplifies build testing
kernels for those platforms a lot, and avoids a lot of inadvertent build
regressions.

Add a dependency for CONFIG_PCI and remove all the ones for PCI specific
device drivers that are currently marked not having it.

There are a few platforms that have an optional MMU, but they usually
cannot have PCI at all. The one exception is Coldfire MCF54xx, but this is
mainly for historic reasons, and anyone using those chips should really use
the MMU these days.

Link: https://lore.kernel.org/lkml/a41f1b20-a76c-43d8-8c36-f12744327a54@app.fastmail.com/
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt; # SCSI
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Acked-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Link: https://patch.msgid.link/20250423202215.3315550-1-arnd@kernel.org
</content>
</entry>
<entry>
<title>Merge tag 'pci-v6.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci</title>
<updated>2025-03-29T02:36:53Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2025-03-29T02:36:53Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7d06015d936c861160803e020f68f413b5c3cd9d'/>
<id>urn:sha1:7d06015d936c861160803e020f68f413b5c3cd9d</id>
<content type='text'>
Pull pci updates from Bjorn Helgaas:
 "Enumeration:

   - Enable Configuration RRS SV, which makes device readiness visible,
     early instead of during child bus scanning (Bjorn Helgaas)

   - Log debug messages about reset methods being used (Bjorn Helgaas)

   - Avoid reset when it has been disabled via sysfs (Nishanth
     Aravamudan)

   - Add common pci-ep-bus.yaml schema for exporting several peripherals
     of a single PCI function via devicetree (Andrea della Porta)

   - 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)

  Resource management:

   - Enlarge devres table[] to accommodate bridge windows, ROM, IOV
     BARs, etc., and validate BAR index in devres interfaces (Philipp
     Stanner)

   - 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)

   - Allow drivers to enable devices even if we haven't assigned
     optional IOV resources to them (Ilpo Järvinen)

   - Rework handling of optional resources (IOV BARs, ROMs) to reduce
     failures if we can't allocate them (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-&gt;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)

  ASPM:

   - Delay pcie_link_state deallocation to avoid dangling pointers that
     cause invalid references during hot-unplug (Daniel Stodden)

  Power management:

   - Allow PCI bridges to go to D3Hot when suspending on all non-x86
     systems (Manivannan Sadhasivam)

  Power control:

   - 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)

  Bandwidth control:

   - Add set_pcie_speed.sh to TEST_PROGS to fix issue when executing the
     set_pcie_cooling_state.sh test case (Yi Lai)

   - Avoid a NULL pointer dereference when we run out of bus numbers to
     assign for a bridge secondary bus (Lukas Wunner)

  Hotplug:

   - Drop superfluous pci_hotplug_slot_list, try_module_get() calls, and
     NULL pointer checks (Lukas Wunner)

   - Drop shpchp module init/exit logging, 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 cpcihp .get_power(), .set_power() function pointers
     (Guilherme Giacomo Simoes)

   - Disable hotplug interrupts in portdrv only when pciehp is not
     enabled to avoid issuing two hotplug commands too close together
     (Feng Tang)

   - Skip pciehp 'device replaced' check if the device has been removed
     to address a 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)

  Virtualization:

   - Fix bugs in 'pci=config_acs=' kernel command line parameter (Tushar
     Dave)

  DOE:

   - Expose supported DOE features via sysfs (Alistair Francis)

   - Allow DOE support to be enabled even if CXL isn't enabled (Alistair
     Francis)

  Endpoint framework:

   - Convert PCI device data so pci-epf-test works correctly on
     big-endian endpoint systems (Niklas Cassel)

   - Add BAR_RESIZABLE type to endpoint framework and add DWC core
     support for EPF drivers to set BAR_RESIZABLE type and size (Niklas
     Cassel)

   - Fix pci-epf-test double free that causes an oops if the host
     reboots and PERST# deassertion restarts endpoint BAR allocation
     (Christian Bruel)

   - Fix endpoint BAR testing so tests can skip disabled BARs instead of
     reporting them as failures (Niklas Cassel)

   - Widen endpoint test BAR size variable to accommodate BARs larger
     than INT_MAX (Niklas Cassel)

   - Remove unused tools 'pci' build target left over after moving tests
     to tools/testing/selftests/pci_endpoint (Jianfeng Liu)

  Altera PCIe controller driver:

   - Add DT binding and driver support for Agilex family (P-Tile,
     F-Tile, R-Tile) (Matthew Gerlach and D M, Sharath Kumar)

  AMD MDB PCIe controller driver:

   - Add DT binding and driver for AMD MDB (Multimedia DMA Bridge)
     (Thippeswamy Havalige)

  Broadcom STB PCIe controller driver:

   - Add BCM2712 MSI-X DT binding and interrupt controller drivers and
     add softdep on irq_bcm2712_mip driver to ensure that it is loaded
     first (Stanimir Varbanov)

   - Expand inbound window map to 64GB so it can accommodate BCM2712
     (Stanimir Varbanov)

   - Add BCM2712 support and DT updates (Stanimir Varbanov)

   - Apply link speed restriction before bringing link up, not after
     (Jim Quinlan)

   - Update Max Link Speed in Link Capabilities via the internal
     writable register, not the read-only config register (Jim Quinlan)

   - Handle regulator_bulk_get() error to avoid panic when we call
     regulator_bulk_free() later (Jim Quinlan)

   - Disable regulators only when removing the bus immediately below a
     Root Port because we don't support regulators deeper in the
     hierarchy (Jim Quinlan)

   - Make const read-only arrays static (Colin Ian King)

  Cadence PCIe endpoint driver:

   - Correct MSG TLP generation so endpoints can generate INTx messages
     (Hans Zhang)

  Freescale i.MX6 PCIe controller driver:

   - Identify the second controller on i.MX8MQ based on devicetree
     'linux,pci-domain' instead of DBI 'reg' address (Richard Zhu)

   - Remove imx_pcie_cpu_addr_fixup() since dwc core can now derive the
     ATU input address (using parent_bus_offset) from devicetree (Frank
     Li)

  Freescale Layerscape PCIe controller driver:

   - Drop deprecated 'num-ib-windows' and 'num-ob-windows' and
     unnecessary 'status' from example (Krzysztof Kozlowski)

   - Correct the syscon_regmap_lookup_by_phandle_args("fsl,pcie-scfg")
     arg_count to fix probe failure on LS1043A (Ioana Ciornei)

  HiSilicon STB PCIe controller driver:

   - Call phy_exit() to clean up if histb_pcie_probe() fails (Christophe
     JAILLET)

  Intel Gateway PCIe controller driver:

   - Remove intel_pcie_cpu_addr() since dwc core can now derive the ATU
     input address (using parent_bus_offset) from devicetree (Frank Li)

  Intel VMD host bridge driver:

   - Convert vmd_dev.cfg_lock from spinlock_t to raw_spinlock_t so
     pci_ops.read() will never sleep, even on PREEMPT_RT where
     spinlock_t becomes a sleepable lock, to avoid calling a sleeping
     function from invalid context (Ryo Takakura)

  MediaTek PCIe Gen3 controller driver:

   - Remove leftover mac_reset assert for Airoha EN7581 SoC (Lorenzo
     Bianconi)

   - Add EN7581 PBUS controller 'mediatek,pbus-csr' DT property and
     program host bridge memory aperture to this syscon node (Lorenzo
     Bianconi)

  Qualcomm PCIe controller driver:

   - Add qcom,pcie-ipq5332 binding (Varadarajan Narayanan)

   - Add qcom i.MX8QM and i.MX8QXP/DXP optional DMA interrupt (Alexander
     Stein)

   - Add optional dma-coherent DT property for Qualcomm SA8775P (Dmitry
     Baryshkov)

   - Make DT iommu property required for SA8775P and prohibited for
     SDX55 (Dmitry Baryshkov)

   - Add DT IOMMU and DMA-related properties for Qualcomm SM8450 (Dmitry
     Baryshkov)

   - Add endpoint DT properties for SAR2130P and enable endpoint mode in
     driver (Dmitry Baryshkov)

   - Describe endpoint BAR0 and BAR2 as 64-bit only and BAR1 and BAR3 as
     RESERVED (Manivannan Sadhasivam)

  Rockchip DesignWare PCIe controller driver:

   - Describe rk3568 and rk3588 BARs as Resizable, not Fixed (Niklas
     Cassel)

  Synopsys DesignWare PCIe controller driver:

   - Add debugfs-based Silicon Debug, Error Injection, Statistical
     Counter support for DWC (Shradha Todi)

   - Add debugfs property to expose LTSSM status of DWC PCIe link (Hans
     Zhang)

   - Add Rockchip support for DWC debugfs features (Niklas Cassel)

   - Add dw_pcie_parent_bus_offset() to look up the parent bus address
     of a specified 'reg' property and return the offset from the CPU
     physical address (Frank Li)

   - Use dw_pcie_parent_bus_offset() to derive CPU -&gt; ATU addr offset
     via 'reg[config]' for host controllers and 'reg[addr_space]' for
     endpoint controllers (Frank Li)

   - Apply struct dw_pcie.parent_bus_offset in ATU users to remove use
     of .cpu_addr_fixup() when programming ATU (Frank Li)

  TI J721E PCIe driver:

   - Correct the 'link down' interrupt bit for J784S4 (Siddharth
     Vadapalli)

  TI Keystone PCIe controller driver:

   - Describe AM65x BARs 2 and 5 as Resizable (not Fixed) and reduce
     alignment requirement from 1MB to 64KB (Niklas Cassel)

  Xilinx Versal CPM PCIe controller driver:

   - Free IRQ domain in probe error path to avoid leaking it
     (Thippeswamy Havalige)

   - Add DT .compatible "xlnx,versal-cpm5nc-host" and driver support for
     Versal Net CPM5NC Root Port controller (Thippeswamy Havalige)

   - Add driver support for CPM5_HOST1 (Thippeswamy Havalige)

  Miscellaneous:

   - Convert fsl,mpc83xx-pcie binding to YAML (J. Neuschäfer)

   - Use for_each_available_child_of_node_scoped() to simplify apple,
     kirin, mediatek, mt7621, tegra drivers (Zhang Zekun)"

* tag 'pci-v6.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (197 commits)
  PCI: layerscape: Fix arg_count to syscon_regmap_lookup_by_phandle_args()
  PCI: j721e: Fix the value of .linkdown_irq_regfield for J784S4
  misc: pci_endpoint_test: Add support for PCITEST_IRQ_TYPE_AUTO
  PCI: endpoint: pci-epf-test: Expose supported IRQ types in CAPS register
  PCI: dw-rockchip: Endpoint mode cannot raise INTx interrupts
  PCI: endpoint: Add intx_capable to epc_features struct
  dt-bindings: PCI: Add common schema for devices accessible through PCI BARs
  PCI: intel-gw: Remove intel_pcie_cpu_addr()
  PCI: imx6: Remove imx_pcie_cpu_addr_fixup()
  PCI: dwc: Use parent_bus_offset to remove need for .cpu_addr_fixup()
  PCI: dwc: ep: Ensure proper iteration over outbound map windows
  PCI: dwc: ep: Use devicetree 'reg[addr_space]' to derive CPU -&gt; ATU addr offset
  PCI: dwc: ep: Consolidate devicetree handling in dw_pcie_ep_get_resources()
  PCI: dwc: ep: Call epc_create() early in dw_pcie_ep_init()
  PCI: dwc: Use devicetree 'reg[config]' to derive CPU -&gt; ATU addr offset
  PCI: dwc: Add dw_pcie_parent_bus_offset() checking and debug
  PCI: dwc: Add dw_pcie_parent_bus_offset()
  PCI/bwctrl: Fix NULL pointer dereference on bus number exhaustion
  PCI: xilinx-cpm: Add cpm_csr register mapping for CPM5_HOST1 variant
  PCI: brcmstb: Make const read-only arrays static
  ...
</content>
</entry>
<entry>
<title>PCI/DOE: Allow enabling DOE without CXL</title>
<updated>2025-03-21T21:36:34Z</updated>
<author>
<name>Alistair Francis</name>
</author>
<published>2025-03-06T07:52:11Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=6fc6ded50ffc09a5cb3a9ec22dd1976401ea0bbc'/>
<id>urn:sha1:6fc6ded50ffc09a5cb3a9ec22dd1976401ea0bbc</id>
<content type='text'>
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 &lt;alistair@alistair23.me&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
</content>
</entry>
<entry>
<title>x86/kaslr: Reduce KASLR entropy on most x86 systems</title>
<updated>2025-02-22T11:25:57Z</updated>
<author>
<name>Balbir Singh</name>
</author>
<published>2025-02-06T23:42:34Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7ffb791423c7c518269a9aad35039ef824a40adb'/>
<id>urn:sha1:7ffb791423c7c518269a9aad35039ef824a40adb</id>
<content type='text'>
When CONFIG_PCI_P2PDMA=y (which is basically enabled on all
large x86 distros), it maps the PFN's via a ZONE_DEVICE
mapping using devm_memremap_pages(). The mapped virtual
address range corresponds to the pci_resource_start()
of the BAR address and size corresponding to the BAR length.

When KASLR is enabled, the direct map range of the kernel is
reduced to the size of physical memory plus additional padding.
If the BAR address is beyond this limit, PCI peer to peer DMA
mappings fail.

Fix this by not shrinking the size of the direct map when
CONFIG_PCI_P2PDMA=y.

This reduces the total available entropy, but it's better than
the current work around of having to disable KASLR completely.

[ mingo: Clarified the changelog to point out the broad impact ... ]

Signed-off-by: Balbir Singh &lt;balbirs@nvidia.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Reviewed-by: Kees Cook &lt;kees@kernel.org&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt; # drivers/pci/Kconfig
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Link: https://lore.kernel.org/lkml/20250206023201.1481957-1-balbirs@nvidia.com/
Link: https://lore.kernel.org/r/20250206234234.1912585-1-balbirs@nvidia.com
--
 arch/x86/mm/kaslr.c | 10 ++++++++--
 drivers/pci/Kconfig |  6 ++++++
 2 files changed, 14 insertions(+), 2 deletions(-)
</content>
</entry>
<entry>
<title>Merge branch 'pci/tph'</title>
<updated>2024-11-25T19:40:55Z</updated>
<author>
<name>Bjorn Helgaas</name>
</author>
<published>2024-11-25T19:40:55Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=ab02bafcecedcd936d9e8526bcf1542642ad2947'/>
<id>urn:sha1:ab02bafcecedcd936d9e8526bcf1542642ad2947</id>
<content type='text'>
- Add and document TLP Processing Hints (TPH) support so drivers can enable
  and disable TPH and the kernel can save/restore TPH configuration (Wei
  Huang)

- Add TPH Steering Tag support so drivers can retrieve Steering Tag values
  associated with specific CPUs via an ACPI _DSM to direct DMA writes
  closer to their consumers (Wei Huang)

* pci/tph:
  PCI/TPH: Add TPH documentation
  PCI/TPH: Add Steering Tag support
  PCI: Add TLP Processing Hints (TPH) support
</content>
</entry>
<entry>
<title>PCI/pwrctrl: Rename pwrctl files to pwrctrl</title>
<updated>2024-11-21T16:01:24Z</updated>
<author>
<name>Bjorn Helgaas</name>
</author>
<published>2024-11-15T21:44:27Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=b88cbaaa6fa109c2eb455d8fe2a318de0d197ea2'/>
<id>urn:sha1:b88cbaaa6fa109c2eb455d8fe2a318de0d197ea2</id>
<content type='text'>
To slightly reduce confusion between "pwrctl" (the power controller and
power sequencing framework) and "bwctrl" (the bandwidth controller),
rename "pwrctl" to "pwrctrl" so they use the same "ctrl" suffix.

Rename drivers/pci/pwrctl/ to drivers/pci/pwrctrl/, including the related
MAINTAINERS, include file (include/linux/pci-pwrctl.h), Makefile, and
Kconfig changes.

This is the minimal rename of files only.  A subsequent commit will rename
functions and data structures.

Link: https://lore.kernel.org/r/20241115214428.2061153-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Krzysztof Wilczyński &lt;kwilczynski@kernel.org&gt;
Acked-by: Krzysztof Wilczyński &lt;kw@linux.com&gt;
</content>
</entry>
<entry>
<title>PCI: Add TLP Processing Hints (TPH) support</title>
<updated>2024-10-02T21:20:01Z</updated>
<author>
<name>Wei Huang</name>
</author>
<published>2024-10-02T16:59:50Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=f69767a1ada3ac74be2e1ac0795a05e1d1384eff'/>
<id>urn:sha1:f69767a1ada3ac74be2e1ac0795a05e1d1384eff</id>
<content type='text'>
Add support for PCIe TLP Processing Hints (TPH) support (see PCIe r6.2,
sec 6.17).

Add TPH register definitions in pci_regs.h, including the TPH Requester
capability register, TPH Requester control register, TPH Completer
capability, and the ST fields of MSI-X entry.

Introduce pcie_enable_tph() and pcie_disable_tph(), enabling drivers to
toggle TPH support and configure specific ST mode as needed. Also add a new
kernel parameter, "pci=notph", allowing users to disable TPH support across
the entire system.

Link: https://lore.kernel.org/r/20241002165954.128085-2-wei.huang2@amd.com
Co-developed-by: Jing Liu &lt;jing2.liu@intel.com&gt;
Co-developed-by: Paul Luse &lt;paul.e.luse@linux.intel.com&gt;
Co-developed-by: Eric Van Tassell &lt;Eric.VanTassell@amd.com&gt;
Signed-off-by: Jing Liu &lt;jing2.liu@intel.com&gt;
Signed-off-by: Paul Luse &lt;paul.e.luse@linux.intel.com&gt;
Signed-off-by: Eric Van Tassell &lt;Eric.VanTassell@amd.com&gt;
Signed-off-by: Wei Huang &lt;wei.huang2@amd.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Ajit Khaparde &lt;ajit.khaparde@broadcom.com&gt;
Reviewed-by: Somnath Kotur &lt;somnath.kotur@broadcom.com&gt;
Reviewed-by: Andy Gospodarek &lt;andrew.gospodarek@broadcom.com&gt;
Reviewed-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Reviewed-by: Lukas Wunner &lt;lukas@wunner.de&gt;
</content>
</entry>
<entry>
<title>PCI/NPEM: Add Native PCIe Enclosure Management support</title>
<updated>2024-09-04T22:25:12Z</updated>
<author>
<name>Mariusz Tkaczyk</name>
</author>
<published>2024-09-04T10:48:47Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4e893545ef8712d25f3176790ebb95beb073637e'/>
<id>urn:sha1:4e893545ef8712d25f3176790ebb95beb073637e</id>
<content type='text'>
Native PCIe Enclosure Management (NPEM, PCIe r6.1 sec 6.28) allows managing
LEDs in storage enclosures. NPEM is indication oriented and it does not
give direct access to LEDs. Although each indication *could* represent an
individual LED, multiple indications could also be represented as a single,
multi-color LED or a single LED blinking in a specific interval.  The
specification leaves that open.

Each enabled indication (capability register bit on) is represented as a
ledclass_dev which can be controlled through sysfs. For every ledclass
device only 2 brightness states are allowed: LED_ON (1) or LED_OFF (0).
This corresponds to the NPEM control register (Indication bit on/off).

Ledclass devices appear in sysfs as child devices (subdirectory) of PCI
device which has an NPEM Extended Capability and indication is enabled in
NPEM capability register. For example, these are LEDs created for pcieport
"10000:02:05.0" on my setup:

  leds/
  ├── 10000:02:05.0:enclosure:fail
  ├── 10000:02:05.0:enclosure:locate
  ├── 10000:02:05.0:enclosure:ok
  └── 10000:02:05.0:enclosure:rebuild

They can be also found in "/sys/class/leds" directory. The parent PCIe
device domain/bus/device/function address is used to guarantee uniqueness
across leds subsystem.

To enable/disable a "fail" indication, the "brightness" file can be edited:

  echo 1 &gt; ./leds/10000:02:05.0:enclosure:fail/brightness
  echo 0 &gt; ./leds/10000:02:05.0:enclosure:fail/brightness

PCIe r6.1, sec 7.9.19.2 defines the possible indications.

Multiple indications for same parent PCIe device can conflict and hardware
may update them when processing new request. To avoid issues, driver
refresh all indications by reading back control register.

This driver expects to be the exclusive NPEM extended capability manager.
It waits up to 1 second after imposing new request, it doesn't verify if
controller is busy before write, and it assumes the mutex lock gives
protection from concurrent updates.

If _DSM LED management is available, we assume the platform may be using
NPEM for its own purposes (see PCI Firmware Spec r3.3 sec 4.7), so the
driver does not use NPEM. A future patch will add _DSM support; an info
message notes whether NPEM or _DSM is being used.

NPEM is a PCIe extended capability so it should be registered in
pcie_init_capabilities() but it is not possible due to LED dependency.  The
parent pci_device must be added earlier for led_classdev_register() to be
successful. NPEM does not require configuration on kernel side, so it is
safe to register LED devices later.

Link: https://lore.kernel.org/r/20240904104848.23480-3-mariusz.tkaczyk@linux.intel.com
Suggested-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Mariusz Tkaczyk &lt;mariusz.tkaczyk@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Tested-by: Stuart Hayes &lt;stuart.w.hayes@gmail.com&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Ilpo Järvinen &lt;ilpo.jarvinen@linux.intel.com&gt;
</content>
</entry>
<entry>
<title>PCI/pwrctl: Add PCI power control core code</title>
<updated>2024-06-12T11:20:56Z</updated>
<author>
<name>Bartosz Golaszewski</name>
</author>
<published>2024-06-12T08:20:17Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4565d2652a37e438e4cd729e2a8dfeffe34c958c'/>
<id>urn:sha1:4565d2652a37e438e4cd729e2a8dfeffe34c958c</id>
<content type='text'>
Some PCI devices must be powered-on before they can be detected on the
bus. Introduce a simple framework reusing the existing PCI OF
infrastructure.

The way this works is: a DT node representing a PCI device connected to
the port can be matched against its power control platform driver. If
the match succeeds, the driver is responsible for powering-up the device
and calling pci_pwrctl_device_set_ready() which will trigger a PCI bus
rescan as well as subscribe to PCI bus notifications.

When the device is detected and created, we'll make it consume the same
DT node that the platform device did. When the device is bound, we'll
create a device link between it and the parent power control device.

Tested-by: Amit Pundir &lt;amit.pundir@linaro.org&gt;
Tested-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt; # on SM8550-QRD, SM8650-QRD &amp; SM8650-HDK
Tested-by: Caleb Connolly &lt;caleb.connolly@linaro.org&gt; # OnePlus 8T
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Link: https://lore.kernel.org/r/20240612082019.19161-5-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski &lt;bartosz.golaszewski@linaro.org&gt;
</content>
</entry>
<entry>
<title>PCI: Move pci_iomap.c to drivers/pci/</title>
<updated>2024-02-12T16:35:40Z</updated>
<author>
<name>Philipp Stanner</name>
</author>
<published>2024-01-31T09:00:21Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=ae874027524c537a15e8d6f14ff69b855bc13ca8'/>
<id>urn:sha1:ae874027524c537a15e8d6f14ff69b855bc13ca8</id>
<content type='text'>
The entirety of pci_iomap.c is guarded by an #ifdef CONFIG_PCI. It,
consequently, does not belong to lib/ because it is not generic
infrastructure.

Move pci_iomap.c to drivers/pci/ and implement the necessary changes to
Makefiles and Kconfigs.

Update MAINTAINERS file.

Update Documentation.

Link: https://lore.kernel.org/r/20240131090023.12331-3-pstanner@redhat.com
[bhelgaas: squash in https://lore.kernel.org/r/20240212150934.24559-1-pstanner@redhat.com]
Suggested-by: Danilo Krummrich &lt;dakr@redhat.com&gt;
Signed-off-by: Philipp Stanner &lt;pstanner@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
</entry>
</feed>
