linux-toradex.git/include/linux/raid, branch master

raid6: hide internals

2026-05-29T04:24:54+00:00

Split out two new headers from the public pq.h:

 - lib/raid/raid6/algos.h contains the algorithm lists private to
   lib/raid/raid6
 - include/linux/raid/pq_tables.h contains the tables also used by
   async_tx providers.

The public include/linux/pq.h is now limited to the public interface for
the consumers of the RAID6 PQ API.

[hch@lst.de: remove duplicate ccflags-y line]
  Link: https://lore.kernel.org/20260527074539.2292913-2-hch@lst.de
Link: https://lore.kernel.org/20260518051804.462141-10-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Ard Biesheuvel 
Tested-by: Ard Biesheuvel  # kunit only on arm64
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

raid6: warn when using less than four devices

2026-05-29T04:24:54+00:00

Quoting H.  Peter Anvin who came up with the RAID6 P/Q algorithm, and who
wrote the initial implementation, then still part of the md driver:

  The RAID-6 code has *never* supported only 3 units, and if it ever
  worked for *any* of the implementations it was purely by accident.
  Speaking as the original author I should know; this was deliberate as
  in some cases the degenerate case (3) would have required extra trays
  in the code to no user benefit.

While md never allowed less than 4 devices, btrfs does.  This new warning
will trigger for such file systems, but given how it already causes havoc
that is a good thing.  If btrfs wants to fix third, it should switch to
transparently use three-way mirroring underneath, which will work as P and
Q are copies of the single data device by the definition of the Linux RAID
6 P/Q algorithm.

Link: https://lore.kernel.org/20260518051804.462141-9-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Ard Biesheuvel 
Tested-by: Ard Biesheuvel  # kunit only on arm64
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

raid6: improve the public interface

2026-05-29T04:24:54+00:00

Stop directly calling into function pointers from users of the RAID6 PQ
API, and provide exported functions with proper documentation and API
guarantees asserts where applicable instead.

Link: https://lore.kernel.org/20260518051804.462141-8-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Ard Biesheuvel 
Tested-by: Ard Biesheuvel  # kunit only on arm64
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

raid6: remove raid6_get_zero_page

2026-05-29T04:24:53+00:00

Just open code it as in other places in the kernel.

Link: https://lore.kernel.org/20260518051804.462141-6-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Ard Biesheuvel 
Tested-by: Ard Biesheuvel  # kunit only on arm64
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

raid6: remove unused defines in pq.h

2026-05-29T04:24:53+00:00

These are not used anywhere in the kernel.

Link: https://lore.kernel.org/20260518051804.462141-5-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Ard Biesheuvel 
Tested-by: Ard Biesheuvel  # kunit only on arm64
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

raid6: remove KERNEL ifdefs

2026-05-29T04:24:52+00:00

With the test code ported to kernel space, none of this is required.

Link: https://lore.kernel.org/20260518051804.462141-3-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Ard Biesheuvel 
Tested-by: Ard Biesheuvel  # kunit only on arm64
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

raid6: turn the userspace test harness into a kunit test

2026-05-29T04:24:52+00:00

Patch series "cleanup the RAID6 P/Q library", v3.

This series cleans up the RAID6 P/Q library to match the recent updates to
the RAID 5 XOR library and other CRC/crypto libraries.  This includes
providing properly documented external interfaces, hiding the internals,
using static_call instead of indirect calls and turning the user space
test suite into an in-kernel kunit test which is also extended to improve
coverage.

Note that this changes registration so that non-priority algorithms are
not registered, which greatly helps with the benchmark time at boot time. 
I'd like to encourage all architecture maintainers to see if they can
further optimized this by registering as few as possible algorithms when
there is a clear benefit in optimized or more unrolled implementations.


This patch (of 18):

Currently the raid6 code can be compiled as userspace code to run the test
suite.  Convert that to be a kunit case with minimal changes to avoid
mutating global state so that we can drop this requirement.

Note that this is not a good kunit test case yet and will need a lot more
work, but that is deferred until the raid6 code is moved to it's new
place, which is easier if the userspace makefile doesn't need adjustments
for the new location first.

Link: https://lore.kernel.org/20260518051804.462141-1-hch@lst.de
Link: https://lore.kernel.org/20260518051804.462141-2-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Ard Biesheuvel 
Tested-by: Ard Biesheuvel  # kunit only on arm64
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

xor: pass the entire operation to the low-level ops

2026-04-03T06:36:21+00:00

Currently the high-level xor code chunks up all operations into small
units for only up to 1 + 4 vectors, and passes it to four different
methods.  This means the FPU/vector context is entered and left a lot for
wide stripes, and a lot of indirect expensive indirect calls are
performed.  Switch to passing the entire gen_xor request to the low-level
ops, and provide a macro to dispatch it to the existing helper.

This reduce the number of indirect calls and FPU/vector context switches
by a factor approaching nr_stripes / 4, and also reduces source and binary
code size.

Link: https://lkml.kernel.org/r/20260327061704.3707577-27-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Eric Biggers 
Tested-by: Eric Biggers 
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Andreas Larsson 
Cc: Anton Ivanov 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David S. Miller 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jason A. Donenfeld 
Cc: Johannes Berg 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Magnus Lindholm 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Richard Henderson 
Cc: Richard Weinberger 
Cc: Russell King 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Ted Ts'o 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

xor: add a better public API

2026-04-03T06:36:20+00:00

xor_blocks is very annoying to use, because it is limited to 4 + 1 sources
/ destinations, has an odd argument order and is completely undocumented.

Lift the code that loops around it from btrfs and async_tx/async_xor into
common code under the name xor_gen and properly document it.

[hch@lst.de: make xor_blocks less annoying to use]
 Link: https://lkml.kernel.org/r/20260327061704.3707577-24-hch@lst.de
Link: https://lkml.kernel.org/r/20260327061704.3707577-23-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Eric Biggers 
Tested-by: Eric Biggers 
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Andreas Larsson 
Cc: Anton Ivanov 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David S. Miller 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jason A. Donenfeld 
Cc: Johannes Berg 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Magnus Lindholm 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Richard Henderson 
Cc: Richard Weinberger 
Cc: Russell King 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Ted Ts'o 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

xor: make xor.ko self-contained in lib/raid/

2026-04-03T06:36:20+00:00

Move the asm/xor.h headers to lib/raid/xor/$(SRCARCH)/xor_arch.h and
include/linux/raid/xor_impl.h to lib/raid/xor/xor_impl.h so that the
xor.ko module implementation is self-contained in lib/raid/.

As this remove the asm-generic mechanism a new kconfig symbol is added to
indicate that a architecture-specific implementations exists, and
xor_arch.h should be included.

Link: https://lkml.kernel.org/r/20260327061704.3707577-22-hch@lst.de
Signed-off-by: Christoph Hellwig 
Reviewed-by: Eric Biggers 
Tested-by: Eric Biggers 
Cc: Albert Ou 
Cc: Alexander Gordeev 
Cc: Alexandre Ghiti 
Cc: Andreas Larsson 
Cc: Anton Ivanov 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: "Borislav Petkov (AMD)" 
Cc: Catalin Marinas 
Cc: Chris Mason 
Cc: Christian Borntraeger 
Cc: Dan Williams 
Cc: David S. Miller 
Cc: David Sterba 
Cc: Heiko Carstens 
Cc: Herbert Xu 
Cc: "H. Peter Anvin" 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jason A. Donenfeld 
Cc: Johannes Berg 
Cc: Li Nan 
Cc: Madhavan Srinivasan 
Cc: Magnus Lindholm 
Cc: Matt Turner 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Richard Henderson 
Cc: Richard Weinberger 
Cc: Russell King 
Cc: Song Liu 
Cc: Sven Schnelle 
Cc: Ted Ts'o 
Cc: Vasily Gorbik 
Cc: WANG Xuerui 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

linux-toradex.git/include/linux/raid, branch master

raid6: hide internals

raid6: warn when using less than four devices

raid6: improve the public interface

raid6: remove raid6_get_zero_page

raid6: remove unused defines in pq.h

raid6: remove __KERNEL__ ifdefs

raid6: turn the userspace test harness into a kunit test

xor: pass the entire operation to the low-level ops

xor: add a better public API

xor: make xor.ko self-contained in lib/raid/

raid6: remove KERNEL ifdefs