opal_mpipl_query_tag() takes a pointer to a 64-bit value, which firmware writes a value to. As OPAL is traditionally big endian this value will be big endian.
This can be confirmed by looking at the implementation in skiboot: static uint64_t opal_mpipl_query_tag(enum opal_mpipl_tags tag, __be64 *tag_val) { ... *tag_val = cpu_to_be64(opal_mpipl_tags[tag]); return OPAL_SUCCESS; } Fix the declaration to annotate that the value is big endian. Signed-off-by: Michael Ellerman <m...@ellerman.id.au> --- arch/powerpc/include/asm/opal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 9986ac34b8e2..c76157237e22 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -307,7 +307,7 @@ int opal_secvar_enqueue_update(const char *key, uint64_t key_len, u8 *data, s64 opal_mpipl_update(enum opal_mpipl_ops op, u64 src, u64 dest, u64 size); s64 opal_mpipl_register_tag(enum opal_mpipl_tags tag, u64 addr); -s64 opal_mpipl_query_tag(enum opal_mpipl_tags tag, u64 *addr); +s64 opal_mpipl_query_tag(enum opal_mpipl_tags tag, __be64 *addr); s64 opal_signal_system_reset(s32 cpu); s64 opal_quiesce(u64 shutdown_type, s32 cpu); -- 2.25.1