diff options
Diffstat (limited to 'plat/arm/css/common/css_scpi.c')
| -rw-r--r-- | plat/arm/css/common/css_scpi.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/plat/arm/css/common/css_scpi.c b/plat/arm/css/common/css_scpi.c index 9e1f9738..02d573c9 100644 --- a/plat/arm/css/common/css_scpi.c +++ b/plat/arm/css/common/css_scpi.c @@ -56,10 +56,10 @@ static void scpi_secure_message_start(void) static void scpi_secure_message_send(size_t payload_size) { - /* Make sure payload can be seen by SCP */ - if (MHU_PAYLOAD_CACHED) - flush_dcache_range(SCPI_SHARED_MEM_AP_TO_SCP, - sizeof(scpi_cmd_t) + payload_size); + /* Ensure that any write to the SCPI payload area is seen by SCP before + * we write to the MHU register. If these 2 writes were reordered by + * the CPU then SCP would read stale payload data */ + dmbst(); mhu_secure_message_send(SCPI_MHU_SLOT_ID); } @@ -79,9 +79,10 @@ static void scpi_secure_message_receive(scpi_cmd_t *cmd) panic(); } - /* Make sure we don't read stale data */ - if (MHU_PAYLOAD_CACHED) - inv_dcache_range(SCPI_SHARED_MEM_SCP_TO_AP, sizeof(*cmd)); + /* Ensure that any read to the SCPI payload area is done after reading + * the MHU register. If these 2 reads were reordered then the CPU would + * read invalid payload data */ + dmbld(); memcpy(cmd, (void *) SCPI_SHARED_MEM_SCP_TO_AP, sizeof(*cmd)); } |