diff options
| -rw-r--r-- | arch/riscv/Kconfig | 13 | ||||
| -rw-r--r-- | arch/riscv/Makefile | 2 |
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 95a2a06acc6a..1ba03a2b509c 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -651,6 +651,19 @@ config RISCV_MISALIGNED load/store for both kernel and userspace. When disable, misaligned accesses will generate SIGBUS in userspace and panic in kernel. +config RISCV_EFFICIENT_UNALIGNED_ACCESS + bool "Assume the CPU supports fast unaligned memory accesses" + depends on NONPORTABLE + select HAVE_EFFICIENT_UNALIGNED_ACCESS + help + Say Y here if you want the kernel to assume that the CPU supports + efficient unaligned memory accesses. When enabled, this option + improves the performance of the kernel on such CPUs. However, the + kernel will run much more slowly, or will not be able to run at all, + on CPUs that do not support efficient unaligned memory accesses. + + If unsure what to do here, say N. + endmenu # "Platform type" menu "Kernel features" diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index a74be78678eb..ebbe02628a27 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -108,7 +108,9 @@ KBUILD_AFLAGS_MODULE += $(call as-option,-Wa$(comma)-mno-relax) # unaligned accesses. While unaligned accesses are explicitly allowed in the # RISC-V ISA, they're emulated by machine mode traps on all extant # architectures. It's faster to have GCC emit only aligned accesses. +ifneq ($(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS),y) KBUILD_CFLAGS += $(call cc-option,-mstrict-align) +endif ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y) prepare: stack_protector_prepare |