Unverified Commit bc38f613 authored by Clément Léger's avatar Clément Léger Committed by Palmer Dabbelt
Browse files

riscv: add support for sysctl unaligned_enabled control 



This sysctl tuning option allows the user to disable misaligned access
handling globally on the system. This will also be used by misaligned
detection code to temporarily disable misaligned access handling.

Signed-off-by: default avatarClément Léger <cleger@rivosinc.com>
Reviewed-by: default avatarBjörn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20231004151405.521596-6-cleger@rivosinc.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 7c586a55

arch/riscv/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -638,6 +638,7 @@ config THREAD_SIZE_ORDER 


config RISCV_MISALIGNED

	bool "Support misaligned load/store traps for kernel and userspace"

	select SYSCTL_ARCH_UNALIGN_ALLOW

	default y

	help

	  Say Y here if you want the kernel to embed support for misaligned

arch/riscv/kernel/traps_misaligned.c

+9 −0
Original line number Diff line number Diff line
@@ -396,6 +396,9 @@ union reg_data { 
	u64 data_u64;

};



/* sysctl hooks */

int unaligned_enabled __read_mostly = 1;	/* Enabled by default */



int handle_misaligned_load(struct pt_regs *regs)

{

	union reg_data val;
@@ -406,6 +409,9 @@ int handle_misaligned_load(struct pt_regs *regs) 


	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);



	if (!unaligned_enabled)

		return -1;



	if (get_insn(regs, epc, &insn))

		return -1;
@@ -502,6 +508,9 @@ int handle_misaligned_store(struct pt_regs *regs) 


	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, addr);



	if (!unaligned_enabled)

		return -1;



	if (get_insn(regs, epc, &insn))

		return -1;