<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/pci/probe.c, branch v6.3</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.3</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.3'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2023-04-20T18:30:14+00:00</updated>
<entry>
<title>PCI: Restrict device disabled status check to DT</title>
<updated>2023-04-20T18:30:14+00:00</updated>
<author>
<name>Rob Herring</name>
<email>robh@kernel.org</email>
</author>
<published>2023-04-19T19:35:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=0d21e71a91debc87e88437a2cf9c6f34f8bf012f'/>
<id>urn:sha1:0d21e71a91debc87e88437a2cf9c6f34f8bf012f</id>
<content type='text'>
Commit 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
checked the firmware device status for both DT and ACPI devices. That
caused a regression in some ACPI systems. The exact reason isn't clear.
It's possibly a firmware bug. For now, at least, refactor the check to
be for DT based systems only.

Note that the original implementation leaked a refcount which is now
correctly handled.

[bhelgaas: Per ACPI r6.5, sec 6.3.7, for devices on an enumerable bus, _STA
must return with bit[0] ("device is present") set]

Link: https://lore.kernel.org/all/m2fs9lgndw.fsf@gmail.com/
Fixes: 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
Link: https://lore.kernel.org/r/20230419193513.708818-1-robh@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217317
Reported-by: Donald Hunter &lt;donald.hunter@gmail.com&gt;
Reported-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Tested-by: Donald Hunter &lt;donald.hunter@gmail.com&gt;
Tested-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Binbin Zhou &lt;zhoubinbin@loongson.cn&gt;
Cc: Liu Peibao &lt;liupeibao@loongson.cn&gt;
Cc: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
</content>
</entry>
<entry>
<title>Merge tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl</title>
<updated>2023-02-25T17:19:23+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-02-25T17:19:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7c3dc440b1f5c75f45e24430f913e561dc82a419'/>
<id>urn:sha1:7c3dc440b1f5c75f45e24430f913e561dc82a419</id>
<content type='text'>
Pull Compute Express Link (CXL) updates from Dan Williams:
 "To date Linux has been dependent on platform-firmware to map CXL RAM
  regions and handle events / errors from devices. With this update we
  can now parse / update the CXL memory layout, and report events /
  errors from devices. This is a precursor for the CXL subsystem to
  handle the end-to-end "RAS" flow for CXL memory. i.e. the flow that
  for DDR-attached-DRAM is handled by the EDAC driver where it maps
  system physical address events to a field-replaceable-unit (FRU /
  endpoint device). In general, CXL has the potential to standardize
  what has historically been a pile of memory-controller-specific error
  handling logic.

  Another change of note is the default policy for handling RAM-backed
  device-dax instances. Previously the default access mode was "device",
  mmap(2) a device special file to access memory. The new default is
  "kmem" where the address range is assigned to the core-mm via
  add_memory_driver_managed(). This saves typical users from wondering
  why their platform memory is not visible via free(1) and stuck behind
  a device-file. At the same time it allows expert users to deploy
  policy to, for example, get dedicated access to high performance
  memory, or hide low performance memory from general purpose kernel
  allocations. This affects not only CXL, but also systems with
  high-bandwidth-memory that platform-firmware tags with the
  EFI_MEMORY_SP (special purpose) designation.

  Summary:

   - CXL RAM region enumeration: instantiate 'struct cxl_region' objects
     for platform firmware created memory regions

   - CXL RAM region provisioning: complement the existing PMEM region
     creation support with RAM region support

   - "Soft Reservation" policy change: Online (memory hot-add)
     soft-reserved memory (EFI_MEMORY_SP) by default, but still allow
     for setting aside such memory for dedicated access via device-dax.

   - CXL Events and Interrupts: Takeover CXL event handling from
     platform-firmware (ACPI calls this CXL Memory Error Reporting) and
     export CXL Events via Linux Trace Events.

   - Convey CXL _OSC results to drivers: Similar to PCI, let the CXL
     subsystem interrogate the result of CXL _OSC negotiation.

   - Emulate CXL DVSEC Range Registers as "decoders": Allow for
     first-generation devices that pre-date the definition of the CXL
     HDM Decoder Capability to translate the CXL DVSEC Range Registers
     into 'struct cxl_decoder' objects.

   - Set timestamp: Per spec, set the device timestamp in case of
     hotplug, or if platform-firwmare failed to set it.

   - General fixups: linux-next build issues, non-urgent fixes for
     pre-production hardware, unit test fixes, spelling and debug
     message improvements"

* tag 'cxl-for-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (66 commits)
  dax/kmem: Fix leak of memory-hotplug resources
  cxl/mem: Add kdoc param for event log driver state
  cxl/trace: Add serial number to trace points
  cxl/trace: Add host output to trace points
  cxl/trace: Standardize device information output
  cxl/pci: Remove locked check for dvsec_range_allowed()
  cxl/hdm: Add emulation when HDM decoders are not committed
  cxl/hdm: Create emulated cxl_hdm for devices that do not have HDM decoders
  cxl/hdm: Emulate HDM decoder from DVSEC range registers
  cxl/pci: Refactor cxl_hdm_decode_init()
  cxl/port: Export cxl_dvsec_rr_decode() to cxl_port
  cxl/pci: Break out range register decoding from cxl_hdm_decode_init()
  cxl: add RAS status unmasking for CXL
  cxl: remove unnecessary calling of pci_enable_pcie_error_reporting()
  dax/hmem: build hmem device support as module if possible
  dax: cxl: add CXL_REGION dependency
  cxl: avoid returning uninitialized error code
  cxl/pmem: Fix nvdimm registration races
  cxl/mem: Fix UAPI command comment
  cxl/uapi: Tag commands from cxl_query_cmd()
  ...
</content>
</entry>
<entry>
<title>Merge branch 'pci/resource'</title>
<updated>2023-02-22T19:47:27+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2023-02-22T19:47:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ebdce9e3d085f7891463fd0046e04201d1604d0d'/>
<id>urn:sha1:ebdce9e3d085f7891463fd0046e04201d1604d0d</id>
<content type='text'>
- Realign space as required by bridge windows after dividing it up (Mika
  Westerberg)

- Account for space required by other devices on the bus before
  distributing it all to bridges (Mika Westerberg)

- Distribute spare resources to root bus devices as well as to other
  hotplug bridges (Mika Westerberg)

- Fix bug that dropped root bus resources that end at zero, e.g., a host
  bridge that leads only to bus 00 (Geert Uytterhoeven)

* pci/resource:
  PCI: Fix dropping valid root bus resources with .end = zero
  PCI: Distribute available resources for root buses, too
  PCI: Take other bus devices into account when distributing resources
  PCI: Align extra resources for hotplug bridges properly
</content>
</entry>
<entry>
<title>PCI: Fix dropping valid root bus resources with .end = zero</title>
<updated>2023-02-13T22:40:45+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert+renesas@glider.be</email>
</author>
<published>2023-02-10T13:46:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9d8ba74a181b1c81def21168795ed96cbe6f05ed'/>
<id>urn:sha1:9d8ba74a181b1c81def21168795ed96cbe6f05ed</id>
<content type='text'>
On r8a7791/koelsch:

  kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
  # cat /sys/kernel/debug/kmemleak
  unreferenced object 0xc3a34e00 (size 64):
    comm "swapper/0", pid 1, jiffies 4294937460 (age 199.080s)
    hex dump (first 32 bytes):
      b4 5d 81 f0 b4 5d 81 f0 c0 b0 a2 c3 00 00 00 00  .]...]..........
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [&lt;fe3aa979&gt;] __kmalloc+0xf0/0x140
      [&lt;34bd6bc0&gt;] resource_list_create_entry+0x18/0x38
      [&lt;767046bc&gt;] pci_add_resource_offset+0x20/0x68
      [&lt;b3f3edf2&gt;] devm_of_pci_get_host_bridge_resources.constprop.0+0xb0/0x390

When coalescing two resources for a contiguous aperture, the second
resource is enlarged to cover the full contiguous range, while the first
resource is marked invalid.  This invalidation is done by clearing the
flags, start, and end members.

When adding the initial resources to the bus later, invalid resources are
skipped.  Unfortunately, the check for an invalid resource considers only
the end member, causing false positives.

E.g. on r8a7791/koelsch, root bus resource 0 ("bus 00") is skipped, and no
longer registered with pci_bus_insert_busn_res() (causing the memory leak),
nor printed:

   pci-rcar-gen2 ee090000.pci: host bridge /soc/pci@ee090000 ranges:
   pci-rcar-gen2 ee090000.pci:      MEM 0x00ee080000..0x00ee08ffff -&gt; 0x00ee080000
   pci-rcar-gen2 ee090000.pci: PCI: revision 11
   pci-rcar-gen2 ee090000.pci: PCI host bridge to bus 0000:00
  -pci_bus 0000:00: root bus resource [bus 00]
   pci_bus 0000:00: root bus resource [mem 0xee080000-0xee08ffff]

Fix this by only skipping resources where all of the flags, start, and end
members are zero.

Fixes: 7c3855c423b17f6c ("PCI: Coalesce host bridge contiguous apertures")
Link: https://lore.kernel.org/r/da0fcd5e86c74239be79c7cb03651c0fce31b515.1676036673.git.geert+renesas@glider.be
Tested-by: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</content>
</entry>
<entry>
<title>PCI: Honor firmware's device disabled status</title>
<updated>2023-02-13T21:29:56+00:00</updated>
<author>
<name>Rob Herring</name>
<email>robh@kernel.org</email>
</author>
<published>2023-02-10T16:43:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6fffbc7ae1373e10b989afe23a9eeb9c49fe15c3'/>
<id>urn:sha1:6fffbc7ae1373e10b989afe23a9eeb9c49fe15c3</id>
<content type='text'>
If a device has a firmware node (DT/ACPI), and the device is marked
disabled, that is currently ignored. Add a check for this condition and
bail out creating the pci_dev.

This assumes the config space for the device can still be accessed because
they already have by this point in order to identify the device.

Link: https://lore.kernel.org/r/20230210164351.2687475-1-robh@kernel.org
Tested-by: Binbin Zhou &lt;zhoubinbin@loongson.cn&gt;
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Liu Peibao &lt;liupeibao@loongson.cn&gt;
Cc: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
</content>
</entry>
<entry>
<title>PCI/CXL: Export native CXL error reporting control</title>
<updated>2023-01-05T21:31:27+00:00</updated>
<author>
<name>Ira Weiny</name>
<email>ira.weiny@intel.com</email>
</author>
<published>2022-12-12T07:06:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=589c3357370a596ef7c99c00baca8ac799fce531'/>
<id>urn:sha1:589c3357370a596ef7c99c00baca8ac799fce531</id>
<content type='text'>
CXL _OSC Error Reporting Control is used by the OS to determine if
Firmware has control of various CXL error reporting capabilities
including the event logs.

Expose the result of negotiating CXL Error Reporting Control in struct
pci_host_bridge for consumption by the CXL drivers.

Cc: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Lukas Wunner &lt;lukas@wunner.de&gt;
Cc: linux-pci@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Reviewed-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Link: https://lore.kernel.org/r/20221212070627.1372402-2-ira.weiny@intel.com
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</content>
</entry>
<entry>
<title>Merge tag 'pci-v6.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci</title>
<updated>2022-12-14T17:54:10+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-14T17:54:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c7020e1b346d5840e93b58cc4f2c67fc645d8df9'/>
<id>urn:sha1:c7020e1b346d5840e93b58cc4f2c67fc645d8df9</id>
<content type='text'>
Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Squash portdrv_{core,pci}.c into portdrv.c to ease maintenance and
     make more things static.

   - Make portdrv bind to Switch Ports that have AER. Previously, if
     these Ports lacked MSI/MSI-X, portdrv failed to bind, which meant
     the Ports couldn't be suspended to low-power states. AER on these
     Ports doesn't use interrupts, and the AER driver doesn't need to
     claim them.

   - Assign PCI domain IDs using ida_alloc(), which makes host bridge
     add/remove work better.

  Resource management:

   - To work better with recent BIOSes that use EfiMemoryMappedIO for
     PCI host bridge apertures, remove those regions from the E820 map
     (E820 entries normally prevent us from allocating BARs). In v5.19,
     we added some quirks to disable E820 checking, but that's not very
     maintainable. EfiMemoryMappedIO means the OS needs to map the
     region for use by EFI runtime services; it shouldn't prevent OS
     from using it.

  PCIe native device hotplug:

   - Build pciehp by default if USB4 is enabled, since Thunderbolt/USB4
     PCIe tunneling depends on native PCIe hotplug.

   - Enable Command Completed Interrupt only if supported to avoid user
     confusion from lspci output that says this is enabled but not
     supported.

   - Prevent pciehp from binding to Switch Upstream Ports; this happened
     because of interaction with acpiphp and caused devices below the
     Upstream Port to disappear.

  Power management:

   - Convert AGP drivers to generic power management. We hope to remove
     legacy power management from the PCI core eventually.

  Virtualization:

   - Fix pci_device_is_present(), which previously always returned
     "false" for VFs, causing virtio hangs when unbinding the driver.

  Miscellaneous:

   - Convert drivers to gpiod API to prepare for dropping some legacy
     code.

   - Fix DOE fencepost error for the maximum data object length.

  Baikal-T1 PCIe controller driver:

   - Add driver and DT bindings.

  Broadcom STB PCIe controller driver:

   - Enable Multi-MSI.

   - Delay 100ms after PERST# deassert to allow power and clocks to
     stabilize.

   - Configure Read Completion Boundary to 64 bytes.

  Freescale i.MX6 PCIe controller driver:

   - Initialize PHY before deasserting core reset to fix a regression in
     v6.0 on boards where the PHY provides the reference.

   - Fix imx6sx and imx8mq clock names in DT schema.

  Intel VMD host bridge driver:

   - Fix Secondary Bus Reset on VMD bridges, which allows reset of NVMe
     SSDs in VT-d pass-through scenarios.

   - Disable MSI remapping, which gets re-enabled by firmware during
     suspend/resume.

  MediaTek PCIe Gen3 controller driver:

   - Add MT7986 and MT8195 support.

  Qualcomm PCIe controller driver:

   - Add SC8280XP/SA8540P basic interconnect support.

  Rockchip DesignWare PCIe controller driver:

   - Base DT schema on common Synopsys schema.

  Synopsys DesignWare PCIe core:

   - Collect DT items shared between Root Port and Endpoint (PERST GPIO,
     PHY info, clocks, resets, link speed, number of lanes, number of
     iATU windows, interrupt info, etc) to snps,dw-pcie-common.yaml.

   - Add dma-ranges support for Root Ports and Endpoints.

   - Consolidate DT resource retrieval for "dbi", "dbi2", "atu", etc. to
     reduce code duplication.

   - Add generic names for clocks and resets to encourage more
     consistent naming across drivers using DesignWare IP.

   - Stop advertising PTM Responder role for Endpoints, which aren't
     allowed to be responders.

  TI J721E PCIe driver:

   - Add j721s2 host mode ID to DT schema.

   - Add interrupt properties to DT schema.

  Toshiba Visconti PCIe controller driver:

   - Fix interrupts array max constraints in DT schema"

* tag 'pci-v6.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (95 commits)
  x86/PCI: Use pr_info() when possible
  x86/PCI: Fix log message typo
  x86/PCI: Tidy E820 removal messages
  PCI: Skip allocate_resource() if too little space available
  efi/x86: Remove EfiMemoryMappedIO from E820 map
  PCI/portdrv: Allow AER service only for Root Ports &amp; RCECs
  PCI: xilinx-nwl: Fix coding style violations
  PCI: mvebu: Switch to using gpiod API
  PCI: pciehp: Enable Command Completed Interrupt only if supported
  PCI: aardvark: Switch to using devm_gpiod_get_optional()
  dt-bindings: PCI: mediatek-gen3: add support for mt7986
  dt-bindings: PCI: mediatek-gen3: add SoC based clock config
  dt-bindings: PCI: qcom: Allow 'dma-coherent' property
  PCI: mt7621: Add sentinel to quirks table
  PCI: vmd: Fix secondary bus reset for Intel bridges
  PCI: endpoint: pci-epf-vntb: Fix sparse ntb-&gt;reg build warning
  PCI: endpoint: pci-epf-vntb: Fix sparse build warning for epf_db
  PCI: endpoint: pci-epf-vntb: Replace hardcoded 4 with sizeof(u32)
  PCI: endpoint: pci-epf-vntb: Remove unused epf_db_phy struct member
  PCI: endpoint: pci-epf-vntb: Fix call pci_epc_mem_free_addr() in error path
  ...
</content>
</entry>
<entry>
<title>Merge tag 'cxl-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl</title>
<updated>2022-12-12T21:55:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-12T21:55:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c1f0fcd85d3d66f002fc1a4986363840fcca766d'/>
<id>urn:sha1:c1f0fcd85d3d66f002fc1a4986363840fcca766d</id>
<content type='text'>
Pull cxl updates from Dan Williams:
 "Compute Express Link (CXL) updates for 6.2.

  While it may seem backwards, the CXL update this time around includes
  some focus on CXL 1.x enabling where the work to date had been with
  CXL 2.0 (VH topologies) in mind.

  First generation CXL can mostly be supported via BIOS, similar to DDR,
  however it became clear there are use cases for OS native CXL error
  handling and some CXL 3.0 endpoint features can be deployed on CXL 1.x
  hosts (Restricted CXL Host (RCH) topologies). So, this update brings
  RCH topologies into the Linux CXL device model.

  In support of the ongoing CXL 2.0+ enabling two new core kernel
  facilities are added.

  One is the ability for the kernel to flag collisions between userspace
  access to PCI configuration registers and kernel accesses. This is
  brought on by the PCIe Data-Object-Exchange (DOE) facility, a hardware
  mailbox over config-cycles.

  The other is a cpu_cache_invalidate_memregion() API that maps to
  wbinvd_on_all_cpus() on x86. To prevent abuse it is disabled in guest
  VMs and architectures that do not support it yet. The CXL paths that
  need it, dynamic memory region creation and security commands (erase /
  unlock), are disabled when it is not present.

  As for the CXL 2.0+ this cycle the subsystem gains support Persistent
  Memory Security commands, error handling in response to PCIe AER
  notifications, and support for the "XOR" host bridge interleave
  algorithm.

  Summary:

   - Add the cpu_cache_invalidate_memregion() API for cache flushing in
     response to physical memory reconfiguration, or memory-side data
     invalidation from operations like secure erase or memory-device
     unlock.

   - Add a facility for the kernel to warn about collisions between
     kernel and userspace access to PCI configuration registers

   - Add support for Restricted CXL Host (RCH) topologies (formerly CXL
     1.1)

   - Add handling and reporting of CXL errors reported via the PCIe AER
     mechanism

   - Add support for CXL Persistent Memory Security commands

   - Add support for the "XOR" algorithm for CXL host bridge interleave

   - Rework / simplify CXL to NVDIMM interactions

   - Miscellaneous cleanups and fixes"

* tag 'cxl-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (71 commits)
  cxl/region: Fix memdev reuse check
  cxl/pci: Remove endian confusion
  cxl/pci: Add some type-safety to the AER trace points
  cxl/security: Drop security command ioctl uapi
  cxl/mbox: Add variable output size validation for internal commands
  cxl/mbox: Enable cxl_mbox_send_cmd() users to validate output size
  cxl/security: Fix Get Security State output payload endian handling
  cxl: update names for interleave ways conversion macros
  cxl: update names for interleave granularity conversion macros
  cxl/acpi: Warn about an invalid CHBCR in an existing CHBS entry
  tools/testing/cxl: Require cache invalidation bypass
  cxl/acpi: Fail decoder add if CXIMS for HBIG is missing
  cxl/region: Fix spelling mistake "memergion" -&gt; "memregion"
  cxl/regs: Fix sparse warning
  cxl/acpi: Set ACPI's CXL _OSC to indicate RCD mode support
  tools/testing/cxl: Add an RCH topology
  cxl/port: Add RCD endpoint port enumeration
  cxl/mem: Move devm_cxl_add_endpoint() from cxl_core to cxl_mem
  tools/testing/cxl: Add XOR Math support to cxl_test
  cxl/acpi: Support CXL XOR Interleave Math (CXIMS)
  ...
</content>
</entry>
<entry>
<title>PCI/MSI: Get rid of PCI_MSI_IRQ_DOMAIN</title>
<updated>2022-11-17T14:15:19+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2022-11-11T13:54:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a474d3fbe287625c6c1cfc56c2a456c5fb7c479e'/>
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What a zoo:

     PCI_MSI
	select GENERIC_MSI_IRQ

     PCI_MSI_IRQ_DOMAIN
     	def_bool y
	depends on PCI_MSI
	select GENERIC_MSI_IRQ_DOMAIN

Ergo PCI_MSI enables PCI_MSI_IRQ_DOMAIN which in turn selects
GENERIC_MSI_IRQ_DOMAIN. So all the dependencies on PCI_MSI_IRQ_DOMAIN are
just an indirection to PCI_MSI.

Match the reality and just admit that PCI_MSI requires
GENERIC_MSI_IRQ_DOMAIN.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Link: https://lore.kernel.org/r/20221111122014.467556921@linutronix.de

</content>
</entry>
<entry>
<title>PCI: Allow drivers to request exclusive config regions</title>
<updated>2022-11-14T18:07:22+00:00</updated>
<author>
<name>Ira Weiny</name>
<email>ira.weiny@intel.com</email>
</author>
<published>2022-09-26T21:57:10+00:00</published>
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PCI config space access from user space has traditionally been
unrestricted with writes being an understood risk for device operation.

Unfortunately, device breakage or odd behavior from config writes lacks
indicators that can leave driver writers confused when evaluating
failures.  This is especially true with the new PCIe Data Object
Exchange (DOE) mailbox protocol where backdoor shenanigans from user
space through things such as vendor defined protocols may affect device
operation without complete breakage.

A prior proposal restricted read and writes completely.[1]  Greg and
Bjorn pointed out that proposal is flawed for a couple of reasons.
First, lspci should always be allowed and should not interfere with any
device operation.  Second, setpci is a valuable tool that is sometimes
necessary and it should not be completely restricted.[2]  Finally
methods exist for full lock of device access if required.

Even though access should not be restricted it would be nice for driver
writers to be able to flag critical parts of the config space such that
interference from user space can be detected.

Introduce pci_request_config_region_exclusive() to mark exclusive config
regions.  Such regions trigger a warning and kernel taint if accessed
via user space.

Create pci_warn_once() to restrict the user from spamming the log.

[1] https://lore.kernel.org/all/161663543465.1867664.5674061943008380442.stgit@dwillia2-desk3.amr.corp.intel.com/
[2] https://lore.kernel.org/all/YF8NGeGv9vYcMfTV@kroah.com/

Cc: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Reviewed-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Suggested-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
Signed-off-by: Ira Weiny &lt;ira.weiny@intel.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Link: https://lore.kernel.org/r/20220926215711.2893286-2-ira.weiny@intel.com
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
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