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2025-11-19raid6: riscv: Allow code to be compiled in userspaceChunyan Zhang1-145/+152
To support userspace raid6test, this patch adds __KERNEL__ ifdef for kernel header inclusions also userspace wrapper definitions to allow code to be compiled in userspace. This patch also drops the NSIZE macro, instead of using the vector length, which can work for both kernel and user space. Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Link: https://patch.msgid.link/20250718072711.3865118-5-zhangchunyan@iscas.ac.cn Signed-off-by: Paul Walmsley <pjw@kernel.org>
2025-11-19raid6: riscv: Prevent compiler from breaking inline vector assembly codeChunyan Zhang1-0/+4
To prevent the compiler from breaking the inline vector assembly code, this code must be built without compiler support for vector. Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Link: https://patch.msgid.link/20250718072711.3865118-4-zhangchunyan@iscas.ac.cn [pjw@kernel.org: cleaned up commit message] Signed-off-by: Paul Walmsley <pjw@kernel.org>
2025-09-17raid6: riscv: replace one load with a move to speed up the caculationChunyan Zhang1-30/+30
Since wp$$==wq$$, it doesn't need to load the same data twice, use move instruction to replace one of the loads to let the program run faster. Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Link: https://lore.kernel.org/r/20250718072711.3865118-3-zhangchunyan@iscas.ac.cn Signed-off-by: Paul Walmsley <pjw@kernel.org>
2025-09-17raid6: riscv: Clean up unused header file inclusionChunyan Zhang1-3/+0
These two C files don't reference things defined in simd.h or types.h so remove these redundant #inclusions. Fixes: 6093faaf9593 ("raid6: Add RISC-V SIMD syndrome and recovery calculations") Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Reviewed-by: Nutty Liu <liujingqi@lanxincomputing.com> Link: https://lore.kernel.org/r/20250718072711.3865118-2-zhangchunyan@iscas.ac.cn Signed-off-by: Paul Walmsley <pjw@kernel.org>
2025-06-12raid6: riscv: Fix NULL pointer dereference caused by a missing clobberChunyan Zhang1-20/+28
When running the raid6 user-space test program on RISC-V QEMU, there's a segmentation fault which seems caused by accessing a NULL pointer, which is the pointer variable p/q in raid6_rvv*_gen/xor_syndrome_real(), p/q should have been equal to dptr[x], but when I use GDB command to see its value, which was 0x10 like below: " Program received signal SIGSEGV, Segmentation fault. 0x0000000000011062 in raid6_rvv2_xor_syndrome_real (disks=<optimized out>, start=0, stop=<optimized out>, bytes=4096, ptrs=<optimized out>) at rvv.c:386 (gdb) p p $1 = (u8 *) 0x10 <error: Cannot access memory at address 0x10> " The issue was found to be related with: 1) Compile optimization There's no segmentation fault if compiling the raid6test program with the optimization flag -O0. 2) The RISC-V vector command vsetvli If not used t0 as the first parameter in vsetvli, there's no segmentation fault either. This patch selects the 2nd solution to fix the issue. [Palmer: The actual issue here is a missing clobber in the vsetvli code. It's a little tricky: we've already probed for VLENB so we don't need to look at the output register, we just need to have an X register in the instruction as that's the form required to actually set VL. Thus we clobber a register, and without describing that we end up breaking compilers.] Fixes: 6093faaf9593 ("raid6: Add RISC-V SIMD syndrome and recovery calculations") Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250610101234.1100660-3-zhangchunyan@iscas.ac.cn Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2025-06-06raid6: Add RISC-V SIMD syndrome and recovery calculationsChunyan Zhang1-0/+1212
The assembly is originally based on the ARM NEON and int.uc, but uses RISC-V vector instructions to implement the RAID6 syndrome and recovery calculations. The functions are tested on QEMU running with the option "-icount shift=0": raid6: rvvx1 gen() 1008 MB/s raid6: rvvx2 gen() 1395 MB/s raid6: rvvx4 gen() 1584 MB/s raid6: rvvx8 gen() 1694 MB/s raid6: int64x8 gen() 113 MB/s raid6: int64x4 gen() 116 MB/s raid6: int64x2 gen() 272 MB/s raid6: int64x1 gen() 229 MB/s raid6: using algorithm rvvx8 gen() 1694 MB/s raid6: .... xor() 1000 MB/s, rmw enabled raid6: using rvv recovery algorithm [Charlie: - Fixup vector options] Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20250305083707.74218-1-zhangchunyan@iscas.ac.cn Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>