RISC-V: add zbb support to string functions

Add handling for ZBB extension and add support for using it as a variant for optimized string functions. Support for the Zbb-str-variants is limited to the GNU-assembler for now, as LLVM has not yet acquired the functionality to selectively change the arch option in assembler code. This is still under review at https://reviews.llvm.org/D123515 Co-developed-by: Christoph Muellner <christoph.muellner@vrull.eu> Signed-off-by: Christoph Muellner <christoph.muellner@vrull.eu> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230113212301.3534711-3-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2026-10-14 05:55:17 +00:00 · 2023-01-13 22:23:01 +01:00 · 2023-01-13 22:23:01 +01:00 · b6fcdb191e
commit b6fcdb191e
parent 56e0790c7f
8 changed files with 334 additions and 1 deletions
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
--- a/arch/riscv/include/asm/errata_list.h
+++ b/arch/riscv/include/asm/errata_list.h
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
--- a/arch/riscv/lib/strcmp.S
+++ b/arch/riscv/lib/strcmp.S
--- a/arch/riscv/lib/strlen.S
+++ b/arch/riscv/lib/strlen.S
--- a/arch/riscv/lib/strncmp.S
+++ b/arch/riscv/lib/strncmp.S