Commit 985a9698 authored by Bibo Mao's avatar Bibo Mao Committed by Huacai Chen
Browse files

KVM: LoongArch: selftests: Add system registers save/restore on exception 



When system returns from exception with ertn instruction, PC comes from
LOONGARCH_CSR_ERA, and CSR.CRMD comes LOONGARCH_CSR_PRMD.

Here save CSR register CSR.ERA and CSR.PRMD into stack, and then restore
them from stack. So it can be modified by exception handlers in future.

Signed-off-by: default avatarBibo Mao <maobibo@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent d3e43a1f

tools/testing/selftests/kvm/include/loongarch/processor.h

+4 −1
Original line number Diff line number Diff line
@@ -124,18 +124,21 @@ struct ex_regs { 
	unsigned long pc;

	unsigned long estat;

	unsigned long badv;

	unsigned long prmd;

};



#define PC_OFFSET_EXREGS		offsetof(struct ex_regs, pc)

#define ESTAT_OFFSET_EXREGS		offsetof(struct ex_regs, estat)

#define BADV_OFFSET_EXREGS		offsetof(struct ex_regs, badv)

#define PRMD_OFFSET_EXREGS		offsetof(struct ex_regs, prmd)

#define EXREGS_SIZE			sizeof(struct ex_regs)



#else

#define PC_OFFSET_EXREGS		((EXREGS_GPRS + 0) * 8)

#define ESTAT_OFFSET_EXREGS		((EXREGS_GPRS + 1) * 8)

#define BADV_OFFSET_EXREGS		((EXREGS_GPRS + 2) * 8)

#define EXREGS_SIZE			((EXREGS_GPRS + 3) * 8)

#define PRMD_OFFSET_EXREGS		((EXREGS_GPRS + 3) * 8)

#define EXREGS_SIZE			((EXREGS_GPRS + 4) * 8)

#endif



#endif /* SELFTEST_KVM_PROCESSOR_H */

tools/testing/selftests/kvm/lib/loongarch/exception.S

+6 −0
Original line number Diff line number Diff line
@@ -51,9 +51,15 @@ handle_exception: 
	st.d   t0, sp, ESTAT_OFFSET_EXREGS

	csrrd  t0, LOONGARCH_CSR_BADV

	st.d   t0, sp, BADV_OFFSET_EXREGS

	csrrd  t0, LOONGARCH_CSR_PRMD

	st.d   t0, sp, PRMD_OFFSET_EXREGS



	or     a0, sp, zero

	bl route_exception

	ld.d   t0, sp, PC_OFFSET_EXREGS

	csrwr  t0, LOONGARCH_CSR_ERA

	ld.d   t0, sp, PRMD_OFFSET_EXREGS

	csrwr  t0, LOONGARCH_CSR_PRMD

	restore_gprs sp

	csrrd  sp, LOONGARCH_CSR_KS0

	ertn