Andy Chiu c2a658d419 riscv: lib: vectorize copy_to_user/copy_from_user ... This patch utilizes Vector to perform copy_to_user/copy_from_user. If Vector is available and the size of copy is large enough for Vector to perform better than scalar, then direct the kernel to do Vector copies for userspace. Though the best programming practice for users is to reduce the copy, this provides a faster variant when copies are inevitable. The optimal size for using Vector, copy_to_user_thres, is only a heuristic for now. We can add DT parsing if people feel the need of customizing it. The exception fixup code of the __asm_vector_usercopy must fallback to the scalar one because accessing user pages might fault, and must be sleepable. Current kernel-mode Vector does not allow tasks to be preemptible, so we must disactivate Vector and perform a scalar fallback in such case. The original implementation of Vector operations comes from https://github.com/sifive/sifive-libc, which we agree to contribute to Linux kernel. Co-developed-by: Jerry Shih <jerry.shih@sifive.com> Signed-off-by: Jerry Shih <jerry.shih@sifive.com> Co-developed-by: Nick Knight <nick.knight@sifive.com> Signed-off-by: Nick Knight <nick.knight@sifive.com> Suggested-by: Guo Ren <guoren@kernel.org> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-6-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>		2024-01-16 07:13:57 -08:00
..
boot	RISC-V Patches for the 6.7 Merge Window, Part 2	2023-11-10 09:23:17 -08:00
configs	RISC-V Patches for the 6.7 Merge Window, Part 2	2023-11-10 09:23:17 -08:00
errata	riscv: errata: andes: Makefile: Fix randconfig build issue	2023-09-27 07:02:48 -07:00
include	riscv: lib: vectorize copy_to_user/copy_from_user	2024-01-16 07:13:57 -08:00
kernel	riscv: sched: defer restoring Vector context for user	2024-01-16 07:13:56 -08:00
kvm	RISC-V Patches for the 6.7 Merge Window, Part 2	2023-11-10 09:23:17 -08:00
lib	riscv: lib: vectorize copy_to_user/copy_from_user	2024-01-16 07:13:57 -08:00
mm	RISC-V Patches for the 6.7 Merge Window, Part 2	2023-11-10 09:23:17 -08:00
net	riscv, bpf: Track both a0 (RISC-V ABI) and a5 (BPF) return values	2023-10-09 15:21:25 +02:00
purgatory	riscv: Use SYM_*() assembly macros instead of deprecated ones	2023-11-06 09:42:47 -08:00
tools	riscv: Check relocations at compile time	2023-04-19 07:46:32 -07:00
Kbuild	kexec: rename ARCH_HAS_KEXEC_PURGATORY	2023-08-18 10:18:54 -07:00
Kconfig	riscv: lib: vectorize copy_to_user/copy_from_user	2024-01-16 07:13:57 -08:00
Kconfig.debug	riscv: Add tests for riscv module loading	2023-11-07 14:59:32 -08:00
Kconfig.errata	riscv: only select DMA_DIRECT_REMAP from RISCV_ISA_ZICBOM and ERRATA_THEAD_PBMT	2023-10-26 09:42:38 +02:00
Kconfig.socs	SoC driver updates for 6.7	2023-11-01 14:46:51 -10:00
Makefile	Merge patch "drivers: perf: Do not broadcast to other cpus when starting a counter"	2023-11-09 06:44:13 -08:00
Makefile.postlink	kbuild: remove ARCH_POSTLINK from module builds	2023-10-28 21:10:08 +09:00