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 in stack, and restore them from stack. So it can be modified by exception handler in future.

Signed-off-by: Bibo Mao maobibo@loongson.cn --- tools/testing/selftests/kvm/include/loongarch/processor.h | 5 ++++- tools/testing/selftests/kvm/lib/loongarch/exception.S | 6 ++++++ 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/include/loongarch/processor.h b/tools/testing/selftests/kvm/include/loongarch/processor.h index 6427a3275e6a..374caddfb0db 100644 --- a/tools/testing/selftests/kvm/include/loongarch/processor.h +++ b/tools/testing/selftests/kvm/include/loongarch/processor.h @@ -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 */ diff --git a/tools/testing/selftests/kvm/lib/loongarch/exception.S b/tools/testing/selftests/kvm/lib/loongarch/exception.S index 88bfa505c6f5..3f1e4b67c5ae 100644 --- a/tools/testing/selftests/kvm/lib/loongarch/exception.S +++ b/tools/testing/selftests/kvm/lib/loongarch/exception.S @@ -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