From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3D9F2363084 for ; Fri, 27 Mar 2026 17:51:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774633886; cv=none; b=ccLGC65ykTKjy3t2R0/spqhwS2vL+HT4GfqNk6f+ImtXuY/y6SPoACK0Y4/FOXNKi92bdO3ZGdDAK6VC7EK/pdJjHLVu0z9/kWxEDTXOnprJ5QV/Qf4wnvUixM8pltrz6HQVFPUecqbHsiSdW6aIRBRmgJwJMzv/N7QkdewmbqY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774633886; c=relaxed/simple; bh=qY5TXHm4pfspA8LHkKMisT5MdrC1antCujxSBcB/5NQ=; h=Date:To:From:Subject:Message-Id; b=KHtUKUmmkkoGiwKbgDYPiW8QzJ/o+eyHc4pCHLD6QOVkEeaqVQD8B7y8BfkyRrKomrosOSh+GAMt7iElh0x0jkWSJ7M98ooDHUlQYpJE8A/ntGMOM9YCsaJIggteQXdoHTdCrtzxlS8V/8BS5Zpme2y4vBXOwz6EnZdy7J6g4Nc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=wXnmNSkm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="wXnmNSkm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F702C19423; Fri, 27 Mar 2026 17:51:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1774633886; bh=qY5TXHm4pfspA8LHkKMisT5MdrC1antCujxSBcB/5NQ=; h=Date:To:From:Subject:From; b=wXnmNSkmCLpniT8U7QKDc6nGpJ5OwVQ+Zaxg1Km2hTvQh8F335FpX6UiFLrtDvOGF VcRZiuXDvoEvxuDN3mUF80wQ9nqmtHbzfoUhdoO4+nSASfoRGAg0auWdZqpFvG9Lrz U3q7jDl3az6h7rXajeOFvkTtpap8IMtrSjU/Qo2M= Date: Fri, 27 Mar 2026 10:51:25 -0700 To: mm-commits@vger.kernel.org,hch@lst.de,akpm@linux-foundation.org From: Andrew Morton Subject: + xor-add-a-better-public-api.patch added to mm-nonmm-unstable branch Message-Id: <20260327175126.0F702C19423@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: xor: add a better public API has been added to the -mm mm-nonmm-unstable branch. Its filename is xor-add-a-better-public-api.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/xor-add-a-better-public-api.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Christoph Hellwig Subject: xor: add a better public API Date: Fri, 27 Mar 2026 07:16:54 +0100 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. Link: https://lkml.kernel.org/r/20260327061704.3707577-23-hch@lst.de Signed-off-by: Christoph Hellwig 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 --- include/linux/raid/xor.h | 2 ++ lib/raid/xor/xor-core.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) --- a/include/linux/raid/xor.h~xor-add-a-better-public-api +++ a/include/linux/raid/xor.h @@ -7,4 +7,6 @@ extern void xor_blocks(unsigned int count, unsigned int bytes, void *dest, void **srcs); +void xor_gen(void *dest, void **srcs, unsigned int src_cnt, unsigned int bytes); + #endif /* _XOR_H */ --- a/lib/raid/xor/xor-core.c~xor-add-a-better-public-api +++ a/lib/raid/xor/xor-core.c @@ -46,6 +46,38 @@ xor_blocks(unsigned int src_count, unsig } EXPORT_SYMBOL(xor_blocks); +/** + * xor_gen - generate RAID-style XOR information + * @dest: destination vector + * @srcs: source vectors + * @src_cnt: number of source vectors + * @bytes: length in bytes of each vector + * + * Performs bit-wise XOR operation into @dest for each of the @src_cnt vectors + * in @srcs for a length of @bytes bytes. @src_cnt must be non-zero, and the + * memory pointed to by @dest and each member of @srcs must be at least 64-byte + * aligned. @bytes must be non-zero and a multiple of 512. + * + * Note: for typical RAID uses, @dest either needs to be zeroed, or filled with + * the first disk, which then needs to be removed from @srcs. + */ +void xor_gen(void *dest, void **srcs, unsigned int src_cnt, unsigned int bytes) +{ + unsigned int src_off = 0; + + WARN_ON_ONCE(bytes & 511); + + while (src_cnt > 0) { + unsigned int this_cnt = min(src_cnt, MAX_XOR_BLOCKS); + + xor_blocks(this_cnt, bytes, dest, srcs + src_off); + + src_cnt -= this_cnt; + src_off += this_cnt; + } +} +EXPORT_SYMBOL(xor_gen); + /* Set of all registered templates. */ static struct xor_block_template *__initdata template_list; static bool __initdata xor_forced = false; _ Patches currently in -mm which might be from hch@lst.de are xor-assert-that-xor_blocks-is-not-call-from-interrupt-context.patch arm-xor-remove-in_interrupt-handling.patch arm64-xor-fix-conflicting-attributes-for-xor_block_template.patch um-xor-cleanup-xorh.patch xor-move-to-lib-raid.patch xor-small-cleanups.patch xor-cleanup-registration-and-probing.patch xor-split-xorh.patch xor-remove-macro-abuse-for-xor-implementation-registrations.patch xor-move-generic-implementations-out-of-asm-generic-xorh.patch alpha-move-the-xor-code-to-lib-raid.patch arm-move-the-xor-code-to-lib-raid.patch arm64-move-the-xor-code-to-lib-raid.patch loongarch-move-the-xor-code-to-lib-raid.patch powerpc-move-the-xor-code-to-lib-raid.patch riscv-move-the-xor-code-to-lib-raid.patch sparc-move-the-xor-code-to-lib-raid.patch s390-move-the-xor-code-to-lib-raid.patch x86-move-the-xor-code-to-lib-raid.patch xor-avoid-indirect-calls-for-arm64-optimized-ops.patch xor-make-xorko-self-contained-in-lib-raid.patch xor-add-a-better-public-api.patch xor-add-a-better-public-api-2.patch async_xor-use-xor_gen.patch btrfs-use-xor_gen.patch xor-pass-the-entire-operation-to-the-low-level-ops.patch xor-use-static_call-for-xor_gen.patch xor-add-a-kunit-test-case.patch