<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/arch/x86/Kconfig, branch v6.2</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.2</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.2'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2022-12-19T13:13:33+00:00</updated>
<entry>
<title>Merge tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2022-12-19T13:13:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-19T13:13:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5f6e430f931d245da838db3e10e918681207029b'/>
<id>urn:sha1:5f6e430f931d245da838db3e10e918681207029b</id>
<content type='text'>
Pull powerpc updates from Michael Ellerman:

 - Add powerpc qspinlock implementation optimised for large system
   scalability and paravirt. See the merge message for more details

 - Enable objtool to be built on powerpc to generate mcount locations

 - Use a temporary mm for code patching with the Radix MMU, so the
   writable mapping is restricted to the patching CPU

 - Add an option to build the 64-bit big-endian kernel with the ELFv2
   ABI

 - Sanitise user registers on interrupt entry on 64-bit Book3S

 - Many other small features and fixes

Thanks to Aboorva Devarajan, Angel Iglesias, Benjamin Gray, Bjorn
Helgaas, Bo Liu, Chen Lifu, Christoph Hellwig, Christophe JAILLET,
Christophe Leroy, Christopher M. Riedl, Colin Ian King, Deming Wang,
Disha Goel, Dmitry Torokhov, Finn Thain, Geert Uytterhoeven, Gustavo A.
R. Silva, Haowen Bai, Joel Stanley, Jordan Niethe, Julia Lawall, Kajol
Jain, Laurent Dufour, Li zeming, Miaoqian Lin, Michael Jeanson, Nathan
Lynch, Naveen N. Rao, Nayna Jain, Nicholas Miehlbradt, Nicholas Piggin,
Pali Rohár, Randy Dunlap, Rohan McLure, Russell Currey, Sathvika
Vasireddy, Shaomin Deng, Stephen Kitt, Stephen Rothwell, Thomas
Weißschuh, Tiezhu Yang, Uwe Kleine-König, Xie Shaowen, Xiu Jianfeng,
XueBing Chen, Yang Yingliang, Zhang Jiaming, ruanjinjie, Jessica Yu,
and Wolfram Sang.

* tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (181 commits)
  powerpc/code-patching: Fix oops with DEBUG_VM enabled
  powerpc/qspinlock: Fix 32-bit build
  powerpc/prom: Fix 32-bit build
  powerpc/rtas: mandate RTAS syscall filtering
  powerpc/rtas: define pr_fmt and convert printk call sites
  powerpc/rtas: clean up includes
  powerpc/rtas: clean up rtas_error_log_max initialization
  powerpc/pseries/eeh: use correct API for error log size
  powerpc/rtas: avoid scheduling in rtas_os_term()
  powerpc/rtas: avoid device tree lookups in rtas_os_term()
  powerpc/rtasd: use correct OF API for event scan rate
  powerpc/rtas: document rtas_call()
  powerpc/pseries: unregister VPA when hot unplugging a CPU
  powerpc/pseries: reset the RCU watchdogs after a LPM
  powerpc: Take in account addition CPU node when building kexec FDT
  powerpc: export the CPU node count
  powerpc/cpuidle: Set CPUIDLE_FLAG_POLLING for snooze state
  powerpc/dts/fsl: Fix pca954x i2c-mux node names
  cxl: Remove unnecessary cxl_pci_window_alignment()
  selftests/powerpc: Fix resource leaks
  ...
</content>
</entry>
<entry>
<title>Merge tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-12-17T20:06:53+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-17T20:06:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4f292c4de4f6fb83776c0ff22674121eb6ddfa2f'/>
<id>urn:sha1:4f292c4de4f6fb83776c0ff22674121eb6ddfa2f</id>
<content type='text'>
Pull x86 mm updates from Dave Hansen:
 "New Feature:

   - Randomize the per-cpu entry areas

  Cleanups:

   - Have CR3_ADDR_MASK use PHYSICAL_PAGE_MASK instead of open coding it

   - Move to "native" set_memory_rox() helper

   - Clean up pmd_get_atomic() and i386-PAE

   - Remove some unused page table size macros"

* tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
  x86/mm: Ensure forced page table splitting
  x86/kasan: Populate shadow for shared chunk of the CPU entry area
  x86/kasan: Add helpers to align shadow addresses up and down
  x86/kasan: Rename local CPU_ENTRY_AREA variables to shorten names
  x86/mm: Populate KASAN shadow for entire per-CPU range of CPU entry area
  x86/mm: Recompute physical address for every page of per-CPU CEA mapping
  x86/mm: Rename __change_page_attr_set_clr(.checkalias)
  x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias()
  x86/mm: Untangle __change_page_attr_set_clr(.checkalias)
  x86/mm: Add a few comments
  x86/mm: Fix CR3_ADDR_MASK
  x86/mm: Remove P*D_PAGE_MASK and P*D_PAGE_SIZE macros
  mm: Convert __HAVE_ARCH_P..P_GET to the new style
  mm: Remove pointless barrier() after pmdp_get_lockless()
  x86/mm/pae: Get rid of set_64bit()
  x86_64: Remove pointless set_64bit() usage
  x86/mm/pae: Be consistent with pXXp_get_and_clear()
  x86/mm/pae: Use WRITE_ONCE()
  x86/mm/pae: Don't (ab)use atomic64
  mm/gup: Fix the lockless PMD access
  ...
</content>
</entry>
<entry>
<title>mm: Rename GUP_GET_PTE_LOW_HIGH</title>
<updated>2022-12-15T18:37:27+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2022-10-21T12:51:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=6ca297d4784625de7b041e8451780643cf5751a4'/>
<id>urn:sha1:6ca297d4784625de7b041e8451780643cf5751a4</id>
<content type='text'>
Since it no longer applies to only PTEs, rename it to PXX.

Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20221022114424.776404066%40infradead.org
</content>
</entry>
<entry>
<title>Merge tag 'gpio-updates-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux</title>
<updated>2022-12-15T17:45:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-15T17:45:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c0f234ff90a211272138be1611ba53f3155ebd78'/>
<id>urn:sha1:c0f234ff90a211272138be1611ba53f3155ebd78</id>
<content type='text'>
Pull gpio updates from Bartosz Golaszewski:
 "We have a new GPIO multiplexer driver, bunch of driver updates and
  refactoring in the core GPIO library.

  GPIO core:
   - teach gpiolib to work with software nodes for HW description
   - remove ARCH_NR_GPIOS treewide as we no longer impose any limit on
     the number of GPIOS since the allocation became entirely dynamic
   - add support for HW quirks for Cirrus CS42L56 codec, Marvell NFC
     controller, Freescale PCIe and Ethernet controller, Himax LCDs and
     Mediatek mt2701
   - refactor OF quirk code
   - some general refactoring of the OF and ACPI code, adding new
     helpers, minor tweaks and fixes, making fwnode usage consistent
     etc.

  GPIO uAPI:
   - fix an issue where the user-space can trigger a NULL-pointer
     dereference in the kernel by opening a device file, forcing a
     driver unbind and then calling one of the syscalls on the
     associated file descriptor

  New drivers:
   - add gpio-latch: a new GPIO multiplexer based on latches connected
     to other GPIOs

  Driver updates:
   - convert i2c GPIO expanders to using .probe_new()
   - drop the gpio-sta2x11 driver
   - factor out common code for the ACCES IDIO-16 family of controllers
     and use this new library wherever applicable in drivers
   - add DT support to gpio-hisi
   - allow building gpio-davinci as a module and increase its maxItems
     property
   - add support for a new model to gpio-pca9570
   - other minor changes to various drivers"

* tag 'gpio-updates-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (66 commits)
  gpio: sim: set a limit on the number of GPIOs
  gpiolib: protect the GPIO device against being dropped while in use by user-space
  gpiolib: cdev: fix NULL-pointer dereferences
  gpiolib: Provide to_gpio_device() helper
  gpiolib: Unify access to the device properties
  gpio: Do not include &lt;linux/kernel.h&gt; when not really needed.
  gpio: pcf857x: Convert to i2c's .probe_new()
  gpio: pca953x: Convert to i2c's .probe_new()
  gpio: max732x: Convert to i2c's .probe_new()
  dt-bindings: gpio: gpio-davinci: Increase maxItems in gpio-line-names
  gpiolib: ensure that fwnode is properly set
  gpio: sl28cpld: Replace irqchip mask_invert with unmask_base
  gpiolib: of: Use correct fwnode for DT-probed chips
  gpiolib: of: Drop redundant check in of_mm_gpiochip_remove()
  gpiolib: of: Prepare of_mm_gpiochip_add_data() for fwnode
  gpiolib: add support for software nodes
  gpiolib: consolidate GPIO lookups
  gpiolib: acpi: avoid leaking ACPI details into upper gpiolib layers
  gpiolib: acpi: teach acpi_find_gpio() to handle data-only nodes
  gpiolib: acpi: change acpi_find_gpio() to accept firmware node
  ...
</content>
</entry>
<entry>
<title>Merge tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-12-14T23:03:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-14T23:03:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=94a855111ed9106971ca2617c5d075269e6aefde'/>
<id>urn:sha1:94a855111ed9106971ca2617c5d075269e6aefde</id>
<content type='text'>
Pull x86 core updates from Borislav Petkov:

 - Add the call depth tracking mitigation for Retbleed which has been
   long in the making. It is a lighterweight software-only fix for
   Skylake-based cores where enabling IBRS is a big hammer and causes a
   significant performance impact.

   What it basically does is, it aligns all kernel functions to 16 bytes
   boundary and adds a 16-byte padding before the function, objtool
   collects all functions' locations and when the mitigation gets
   applied, it patches a call accounting thunk which is used to track
   the call depth of the stack at any time.

   When that call depth reaches a magical, microarchitecture-specific
   value for the Return Stack Buffer, the code stuffs that RSB and
   avoids its underflow which could otherwise lead to the Intel variant
   of Retbleed.

   This software-only solution brings a lot of the lost performance
   back, as benchmarks suggest:

       https://lore.kernel.org/all/20220915111039.092790446@infradead.org/

   That page above also contains a lot more detailed explanation of the
   whole mechanism

 - Implement a new control flow integrity scheme called FineIBT which is
   based on the software kCFI implementation and uses hardware IBT
   support where present to annotate and track indirect branches using a
   hash to validate them

 - Other misc fixes and cleanups

* tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits)
  x86/paravirt: Use common macro for creating simple asm paravirt functions
  x86/paravirt: Remove clobber bitmask from .parainstructions
  x86/debug: Include percpu.h in debugreg.h to get DECLARE_PER_CPU() et al
  x86/cpufeatures: Move X86_FEATURE_CALL_DEPTH from bit 18 to bit 19 of word 11, to leave space for WIP X86_FEATURE_SGX_EDECCSSA bit
  x86/Kconfig: Enable kernel IBT by default
  x86,pm: Force out-of-line memcpy()
  objtool: Fix weak hole vs prefix symbol
  objtool: Optimize elf_dirty_reloc_sym()
  x86/cfi: Add boot time hash randomization
  x86/cfi: Boot time selection of CFI scheme
  x86/ibt: Implement FineIBT
  objtool: Add --cfi to generate the .cfi_sites section
  x86: Add prefix symbols for function padding
  objtool: Add option to generate prefix symbols
  objtool: Avoid O(bloody terrible) behaviour -- an ode to libelf
  objtool: Slice up elf_create_section_symbol()
  kallsyms: Revert "Take callthunks into account"
  x86: Unconfuse CONFIG_ and X86_FEATURE_ namespaces
  x86/retpoline: Fix crash printing warning
  x86/paravirt: Fix a !PARAVIRT build warning
  ...
</content>
</entry>
<entry>
<title>Merge tag 'x86_boot_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-12-13T22:45:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-13T22:45:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4eb77fa102ebc2a48d61941fd0293b0aeed00fee'/>
<id>urn:sha1:4eb77fa102ebc2a48d61941fd0293b0aeed00fee</id>
<content type='text'>
Pull x86 boot updates from Borislav Petkov:
 "A  of early boot cleanups and fixes.

   - Do some spring cleaning to the compressed boot code by moving the
     EFI mixed-mode code to a separate compilation unit, the AMD memory
     encryption early code where it belongs and fixing up build
     dependencies. Make the deprecated EFI handover protocol optional
     with the goal of removing it at some point (Ard Biesheuvel)

   - Skip realmode init code on Xen PV guests as it is not needed there

   - Remove an old 32-bit PIC code compiler workaround"

* tag 'x86_boot_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Remove x86_32 PIC using %ebx workaround
  x86/boot: Skip realmode init code when running as Xen PV guest
  x86/efi: Make the deprecated EFI handover protocol optional
  x86/boot/compressed: Only build mem_encrypt.S if AMD_MEM_ENCRYPT=y
  x86/boot/compressed: Adhere to calling convention in get_sev_encryption_bit()
  x86/boot/compressed: Move startup32_check_sev_cbit() out of head_64.S
  x86/boot/compressed: Move startup32_check_sev_cbit() into .text
  x86/boot/compressed: Move startup32_load_idt() out of head_64.S
  x86/boot/compressed: Move startup32_load_idt() into .text section
  x86/boot/compressed: Pull global variable reference into startup32_load_idt()
  x86/boot/compressed: Avoid touching ECX in startup32_set_idt_entry()
  x86/boot/compressed: Simplify IDT/GDT preserve/restore in the EFI thunk
  x86/boot/compressed, efi: Merge multiple definitions of image_offset into one
  x86/boot/compressed: Move efi32_pe_entry() out of head_64.S
  x86/boot/compressed: Move efi32_entry out of head_64.S
  x86/boot/compressed: Move efi32_pe_entry into .text section
  x86/boot/compressed: Move bootargs parsing out of 32-bit startup code
  x86/boot/compressed: Move 32-bit entrypoint code into .text section
  x86/boot/compressed: Rename efi_thunk_64.S to efi-mixed.S
</content>
</entry>
<entry>
<title>Merge tag 'efi-next-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi</title>
<updated>2022-12-13T22:31:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-13T22:31:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=fc4c9f450493daef1c996c9d4b3c647ec3121509'/>
<id>urn:sha1:fc4c9f450493daef1c996c9d4b3c647ec3121509</id>
<content type='text'>
Pull EFI updates from Ard Biesheuvel:
 "Another fairly sizable pull request, by EFI subsystem standards.

  Most of the work was done by me, some of it in collaboration with the
  distro and bootloader folks (GRUB, systemd-boot), where the main focus
  has been on removing pointless per-arch differences in the way EFI
  boots a Linux kernel.

   - Refactor the zboot code so that it incorporates all the EFI stub
     logic, rather than calling the decompressed kernel as a EFI app.

   - Add support for initrd= command line option to x86 mixed mode.

   - Allow initrd= to be used with arbitrary EFI accessible file systems
     instead of just the one the kernel itself was loaded from.

   - Move some x86-only handling and manipulation of the EFI memory map
     into arch/x86, as it is not used anywhere else.

   - More flexible handling of any random seeds provided by the boot
     environment (i.e., systemd-boot) so that it becomes available much
     earlier during the boot.

   - Allow improved arch-agnostic EFI support in loaders, by setting a
     uniform baseline of supported features, and adding a generic magic
     number to the DOS/PE header. This should allow loaders such as GRUB
     or systemd-boot to reduce the amount of arch-specific handling
     substantially.

   - (arm64) Run EFI runtime services from a dedicated stack, and use it
     to recover from synchronous exceptions that might occur in the
     firmware code.

   - (arm64) Ensure that we don't allocate memory outside of the 48-bit
     addressable physical range.

   - Make EFI pstore record size configurable

   - Add support for decoding CXL specific CPER records"

* tag 'efi-next-for-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (43 commits)
  arm64: efi: Recover from synchronous exceptions occurring in firmware
  arm64: efi: Execute runtime services from a dedicated stack
  arm64: efi: Limit allocations to 48-bit addressable physical region
  efi: Put Linux specific magic number in the DOS header
  efi: libstub: Always enable initrd command line loader and bump version
  efi: stub: use random seed from EFI variable
  efi: vars: prohibit reading random seed variables
  efi: random: combine bootloader provided RNG seed with RNG protocol output
  efi/cper, cxl: Decode CXL Error Log
  efi/cper, cxl: Decode CXL Protocol Error Section
  efi: libstub: fix efi_load_initrd_dev_path() kernel-doc comment
  efi: x86: Move EFI runtime map sysfs code to arch/x86
  efi: runtime-maps: Clarify purpose and enable by default for kexec
  efi: pstore: Add module parameter for setting the record size
  efi: xen: Set EFI_PARAVIRT for Xen dom0 boot on all architectures
  efi: memmap: Move manipulation routines into x86 arch tree
  efi: memmap: Move EFI fake memmap support into x86 arch tree
  efi: libstub: Undeprecate the command line initrd loader
  efi: libstub: Add mixed mode support to command line initrd loader
  efi: libstub: Permit mixed mode return types other than efi_status_t
  ...
</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>Merge tag 'x86-apic-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-12-12T20:30:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-12T20:30:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=369013162f7a7aed9e685e4763c3395700e909ad'/>
<id>urn:sha1:369013162f7a7aed9e685e4763c3395700e909ad</id>
<content type='text'>
Pull x86 apic update from Thomas Gleixner:
 "A set of changes for the x86 APIC code:

   - Handle the case where x2APIC is enabled and locked by the BIOS on a
     kernel with CONFIG_X86_X2APIC=n gracefully.

     Instead of a panic which does not make it to the graphical console
     during very early boot, simply disable the local APIC completely
     and boot with the PIC and very limited functionality, which allows
     to diagnose the issue

   - Convert x86 APIC device tree bindings to YAML

   - Extend x86 APIC device tree bindings to configure interrupt
     delivery mode and handle this in during init. This allows to boot
     with device tree on platforms which lack a legacy PIC"

* tag 'x86-apic-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/of: Add support for boot time interrupt delivery mode configuration
  x86/of: Replace printk(KERN_LVL) with pr_lvl()
  dt-bindings: x86: apic: Introduce new optional bool property for lapic
  dt-bindings: x86: apic: Convert Intel's APIC bindings to YAML schema
  x86/of: Remove unused early_init_dt_add_memory_arch()
  x86/apic: Handle no CONFIG_X86_X2APIC on systems with x2APIC enabled by BIOS
</content>
</entry>
<entry>
<title>Merge tag 'irq-core-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-12-12T19:21:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-12-12T19:21:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9d33edb20f7e6943250d6bb96ceaf2368f674d51'/>
<id>urn:sha1:9d33edb20f7e6943250d6bb96ceaf2368f674d51</id>
<content type='text'>
Pull irq updates from Thomas Gleixner:
 "Updates for the interrupt core and driver subsystem:

  The bulk is the rework of the MSI subsystem to support per device MSI
  interrupt domains. This solves conceptual problems of the current
  PCI/MSI design which are in the way of providing support for
  PCI/MSI[-X] and the upcoming PCI/IMS mechanism on the same device.

  IMS (Interrupt Message Store] is a new specification which allows
  device manufactures to provide implementation defined storage for MSI
  messages (as opposed to PCI/MSI and PCI/MSI-X that has a specified
  message store which is uniform accross all devices). The PCI/MSI[-X]
  uniformity allowed us to get away with "global" PCI/MSI domains.

  IMS not only allows to overcome the size limitations of the MSI-X
  table, but also gives the device manufacturer the freedom to store the
  message in arbitrary places, even in host memory which is shared with
  the device.

  There have been several attempts to glue this into the current MSI
  code, but after lengthy discussions it turned out that there is a
  fundamental design problem in the current PCI/MSI-X implementation.
  This needs some historical background.

  When PCI/MSI[-X] support was added around 2003, interrupt management
  was completely different from what we have today in the actively
  developed architectures. Interrupt management was completely
  architecture specific and while there were attempts to create common
  infrastructure the commonalities were rudimentary and just providing
  shared data structures and interfaces so that drivers could be written
  in an architecture agnostic way.

  The initial PCI/MSI[-X] support obviously plugged into this model
  which resulted in some basic shared infrastructure in the PCI core
  code for setting up MSI descriptors, which are a pure software
  construct for holding data relevant for a particular MSI interrupt,
  but the actual association to Linux interrupts was completely
  architecture specific. This model is still supported today to keep
  museum architectures and notorious stragglers alive.

  In 2013 Intel tried to add support for hot-pluggable IO/APICs to the
  kernel, which was creating yet another architecture specific mechanism
  and resulted in an unholy mess on top of the existing horrors of x86
  interrupt handling. The x86 interrupt management code was already an
  incomprehensible maze of indirections between the CPU vector
  management, interrupt remapping and the actual IO/APIC and PCI/MSI[-X]
  implementation.

  At roughly the same time ARM struggled with the ever growing SoC
  specific extensions which were glued on top of the architected GIC
  interrupt controller.

  This resulted in a fundamental redesign of interrupt management and
  provided the today prevailing concept of hierarchical interrupt
  domains. This allowed to disentangle the interactions between x86
  vector domain and interrupt remapping and also allowed ARM to handle
  the zoo of SoC specific interrupt components in a sane way.

  The concept of hierarchical interrupt domains aims to encapsulate the
  functionality of particular IP blocks which are involved in interrupt
  delivery so that they become extensible and pluggable. The X86
  encapsulation looks like this:

                                            |--- device 1
     [Vector]---[Remapping]---[PCI/MSI]--|...
                                            |--- device N

  where the remapping domain is an optional component and in case that
  it is not available the PCI/MSI[-X] domains have the vector domain as
  their parent. This reduced the required interaction between the
  domains pretty much to the initialization phase where it is obviously
  required to establish the proper parent relation ship in the
  components of the hierarchy.

  While in most cases the model is strictly representing the chain of IP
  blocks and abstracting them so they can be plugged together to form a
  hierarchy, the design stopped short on PCI/MSI[-X]. Looking at the
  hardware it's clear that the actual PCI/MSI[-X] interrupt controller
  is not a global entity, but strict a per PCI device entity.

  Here we took a short cut on the hierarchical model and went for the
  easy solution of providing "global" PCI/MSI domains which was possible
  because the PCI/MSI[-X] handling is uniform across the devices. This
  also allowed to keep the existing PCI/MSI[-X] infrastructure mostly
  unchanged which in turn made it simple to keep the existing
  architecture specific management alive.

  A similar problem was created in the ARM world with support for IP
  block specific message storage. Instead of going all the way to stack
  a IP block specific domain on top of the generic MSI domain this ended
  in a construct which provides a "global" platform MSI domain which
  allows overriding the irq_write_msi_msg() callback per allocation.

  In course of the lengthy discussions we identified other abuse of the
  MSI infrastructure in wireless drivers, NTB etc. where support for
  implementation specific message storage was just mindlessly glued into
  the existing infrastructure. Some of this just works by chance on
  particular platforms but will fail in hard to diagnose ways when the
  driver is used on platforms where the underlying MSI interrupt
  management code does not expect the creative abuse.

  Another shortcoming of today's PCI/MSI-X support is the inability to
  allocate or free individual vectors after the initial enablement of
  MSI-X. This results in an works by chance implementation of VFIO (PCI
  pass-through) where interrupts on the host side are not set up upfront
  to avoid resource exhaustion. They are expanded at run-time when the
  guest actually tries to use them. The way how this is implemented is
  that the host disables MSI-X and then re-enables it with a larger
  number of vectors again. That works by chance because most device
  drivers set up all interrupts before the device actually will utilize
  them. But that's not universally true because some drivers allocate a
  large enough number of vectors but do not utilize them until it's
  actually required, e.g. for acceleration support. But at that point
  other interrupts of the device might be in active use and the MSI-X
  disable/enable dance can just result in losing interrupts and
  therefore hard to diagnose subtle problems.

  Last but not least the "global" PCI/MSI-X domain approach prevents to
  utilize PCI/MSI[-X] and PCI/IMS on the same device due to the fact
  that IMS is not longer providing a uniform storage and configuration
  model.

  The solution to this is to implement the missing step and switch from
  global PCI/MSI domains to per device PCI/MSI domains. The resulting
  hierarchy then looks like this:

                              |--- [PCI/MSI] device 1
     [Vector]---[Remapping]---|...
                              |--- [PCI/MSI] device N

  which in turn allows to provide support for multiple domains per
  device:

                              |--- [PCI/MSI] device 1
                              |--- [PCI/IMS] device 1
     [Vector]---[Remapping]---|...
                              |--- [PCI/MSI] device N
                              |--- [PCI/IMS] device N

  This work converts the MSI and PCI/MSI core and the x86 interrupt
  domains to the new model, provides new interfaces for post-enable
  allocation/free of MSI-X interrupts and the base framework for
  PCI/IMS. PCI/IMS has been verified with the work in progress IDXD
  driver.

  There is work in progress to convert ARM over which will replace the
  platform MSI train-wreck. The cleanup of VFIO, NTB and other creative
  "solutions" are in the works as well.

  Drivers:

   - Updates for the LoongArch interrupt chip drivers

   - Support for MTK CIRQv2

   - The usual small fixes and updates all over the place"

* tag 'irq-core-2022-12-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (134 commits)
  irqchip/ti-sci-inta: Fix kernel doc
  irqchip/gic-v2m: Mark a few functions __init
  irqchip/gic-v2m: Include arm-gic-common.h
  irqchip/irq-mvebu-icu: Fix works by chance pointer assignment
  iommu/amd: Enable PCI/IMS
  iommu/vt-d: Enable PCI/IMS
  x86/apic/msi: Enable PCI/IMS
  PCI/MSI: Provide pci_ims_alloc/free_irq()
  PCI/MSI: Provide IMS (Interrupt Message Store) support
  genirq/msi: Provide constants for PCI/IMS support
  x86/apic/msi: Enable MSI_FLAG_PCI_MSIX_ALLOC_DYN
  PCI/MSI: Provide post-enable dynamic allocation interfaces for MSI-X
  PCI/MSI: Provide prepare_desc() MSI domain op
  PCI/MSI: Split MSI-X descriptor setup
  genirq/msi: Provide MSI_FLAG_MSIX_ALLOC_DYN
  genirq/msi: Provide msi_domain_alloc_irq_at()
  genirq/msi: Provide msi_domain_ops:: Prepare_desc()
  genirq/msi: Provide msi_desc:: Msi_data
  genirq/msi: Provide struct msi_map
  x86/apic/msi: Remove arch_create_remap_msi_irq_domain()
  ...
</content>
</entry>
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