raid6: improve the public interface

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 <hch@lst.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Ard Biesheuvel <ardb@kernel.org> # kunit only on arm64
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Li Nan <linan122@huawei.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Song Liu <song@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 10 insertions, 9 deletions

diff --git a/include/linux/raid/pq.h b/include/linux/raid/pq.h
index f27a866c287f..425a227591c0 100644
--- a/include/linux/raid/pq.h
+++ b/include/linux/raid/pq.h
@@ -11,6 +11,16 @@
 #include <linux/blkdev.h>
 #include <linux/mm.h>
 
+void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs);
+void raid6_xor_syndrome(int disks, int start, int stop, size_t bytes,
+		void **ptrs);
+bool raid6_can_xor_syndrome(void);
+
+void raid6_recov_2data(int disks, size_t bytes, int faila, int failb,
+		void **ptrs);
+void raid6_recov_datap(int disks, size_t bytes, int faila,
+		void **ptrs);
+
 /* Routine choices */
 struct raid6_calls {
 	void (*gen_syndrome)(int, size_t, void **);
@@ -20,9 +30,6 @@ struct raid6_calls {
 	int priority;		/* Relative priority ranking if non-zero */
 };
 
-/* Selected algorithm */
-extern struct raid6_calls raid6_call;
-
 /* Various routine sets */
 extern const struct raid6_calls raid6_intx1;
 extern const struct raid6_calls raid6_intx2;
@@ -92,10 +99,4 @@ extern const u8 raid6_gflog[256]      __attribute__((aligned(256)));
 extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
 extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));
 
-/* Recovery routines */
-extern void (*raid6_2data_recov)(int disks, size_t bytes, int faila, int failb,
-		       void **ptrs);
-extern void (*raid6_datap_recov)(int disks, size_t bytes, int faila,
-			void **ptrs);
-
 #endif /* LINUX_RAID_RAID6_H */