feat(spmc): add support for direct req/resp
Enable the SPMC to handle FFA_MSG_SEND_DIRECT_REQ and
FFA_MSG_SEND_DIRECT_RESP ABIs.
Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Change-Id: Ia196c7405993f600e4fdbf467397ea3fb035a62a
diff --git a/services/std_svc/spm/el3_spmc/spmc_main.c b/services/std_svc/spm/el3_spmc/spmc_main.c
index cfd5a80..3fd8c78 100644
--- a/services/std_svc/spm/el3_spmc/spmc_main.c
+++ b/services/std_svc/spm/el3_spmc/spmc_main.c
@@ -179,6 +179,166 @@
/*******************************************************************************
* FF-A ABI Handlers.
******************************************************************************/
+
+/*******************************************************************************
+ * Helper function to validate arg2 as part of a direct message.
+ ******************************************************************************/
+static inline bool direct_msg_validate_arg2(uint64_t x2)
+{
+ /*
+ * We currently only support partition messages, therefore ensure x2 is
+ * not set.
+ */
+ if (x2 != (uint64_t) 0) {
+ VERBOSE("Arg2 MBZ for partition messages (0x%lx).\n", x2);
+ return false;
+ }
+ return true;
+}
+
+/*******************************************************************************
+ * Handle direct request messages and route to the appropriate destination.
+ ******************************************************************************/
+static uint64_t direct_req_smc_handler(uint32_t smc_fid,
+ bool secure_origin,
+ uint64_t x1,
+ uint64_t x2,
+ uint64_t x3,
+ uint64_t x4,
+ void *cookie,
+ void *handle,
+ uint64_t flags)
+{
+ uint16_t dst_id = ffa_endpoint_destination(x1);
+ struct secure_partition_desc *sp;
+ unsigned int idx;
+
+ /* Check if arg2 has been populated correctly based on message type. */
+ if (!direct_msg_validate_arg2(x2)) {
+ return spmc_ffa_error_return(handle,
+ FFA_ERROR_INVALID_PARAMETER);
+ }
+
+ /*
+ * If called by the secure world it is an invalid call since a
+ * SP cannot call into the Normal world and there is no other SP to call
+ * into. If there are other SPs in future then the partition runtime
+ * model would need to be validated as well.
+ */
+ if (secure_origin) {
+ VERBOSE("Direct request not supported to the Normal World.\n");
+ return spmc_ffa_error_return(handle,
+ FFA_ERROR_INVALID_PARAMETER);
+ }
+
+ /* Check if the SP ID is valid. */
+ sp = spmc_get_sp_ctx(dst_id);
+ if (sp == NULL) {
+ VERBOSE("Direct request to unknown partition ID (0x%x).\n",
+ dst_id);
+ return spmc_ffa_error_return(handle,
+ FFA_ERROR_INVALID_PARAMETER);
+ }
+
+ /*
+ * Check that the target execution context is in a waiting state before
+ * forwarding the direct request to it.
+ */
+ idx = get_ec_index(sp);
+ if (sp->ec[idx].rt_state != RT_STATE_WAITING) {
+ VERBOSE("SP context on core%u is not waiting (%u).\n",
+ idx, sp->ec[idx].rt_model);
+ return spmc_ffa_error_return(handle, FFA_ERROR_BUSY);
+ }
+
+ /*
+ * Everything checks out so forward the request to the SP after updating
+ * its state and runtime model.
+ */
+ sp->ec[idx].rt_state = RT_STATE_RUNNING;
+ sp->ec[idx].rt_model = RT_MODEL_DIR_REQ;
+ return spmc_smc_return(smc_fid, secure_origin, x1, x2, x3, x4,
+ handle, cookie, flags, dst_id);
+}
+
+/*******************************************************************************
+ * Handle direct response messages and route to the appropriate destination.
+ ******************************************************************************/
+static uint64_t direct_resp_smc_handler(uint32_t smc_fid,
+ bool secure_origin,
+ uint64_t x1,
+ uint64_t x2,
+ uint64_t x3,
+ uint64_t x4,
+ void *cookie,
+ void *handle,
+ uint64_t flags)
+{
+ uint16_t dst_id = ffa_endpoint_destination(x1);
+ struct secure_partition_desc *sp;
+ unsigned int idx;
+
+ /* Check if arg2 has been populated correctly based on message type. */
+ if (!direct_msg_validate_arg2(x2)) {
+ return spmc_ffa_error_return(handle,
+ FFA_ERROR_INVALID_PARAMETER);
+ }
+
+ /* Check that the response did not originate from the Normal world. */
+ if (!secure_origin) {
+ VERBOSE("Direct Response not supported from Normal World.\n");
+ return spmc_ffa_error_return(handle,
+ FFA_ERROR_INVALID_PARAMETER);
+ }
+
+ /*
+ * Check that the response is either targeted to the Normal world or the
+ * SPMC e.g. a PM response.
+ */
+ if ((dst_id != FFA_SPMC_ID) && ffa_is_secure_world_id(dst_id)) {
+ VERBOSE("Direct response to invalid partition ID (0x%x).\n",
+ dst_id);
+ return spmc_ffa_error_return(handle,
+ FFA_ERROR_INVALID_PARAMETER);
+ }
+
+ /* Obtain the SP descriptor and update its runtime state. */
+ sp = spmc_get_sp_ctx(ffa_endpoint_source(x1));
+ if (sp == NULL) {
+ VERBOSE("Direct response to unknown partition ID (0x%x).\n",
+ dst_id);
+ return spmc_ffa_error_return(handle,
+ FFA_ERROR_INVALID_PARAMETER);
+ }
+
+ /* Sanity check state is being tracked correctly in the SPMC. */
+ idx = get_ec_index(sp);
+ assert(sp->ec[idx].rt_state == RT_STATE_RUNNING);
+
+ /* Ensure SP execution context was in the right runtime model. */
+ if (sp->ec[idx].rt_model != RT_MODEL_DIR_REQ) {
+ VERBOSE("SP context on core%u not handling direct req (%u).\n",
+ idx, sp->ec[idx].rt_model);
+ return spmc_ffa_error_return(handle, FFA_ERROR_DENIED);
+ }
+
+ /* Update the state of the SP execution context. */
+ sp->ec[idx].rt_state = RT_STATE_WAITING;
+
+ /*
+ * If the receiver is not the SPMC then forward the response to the
+ * Normal world.
+ */
+ if (dst_id == FFA_SPMC_ID) {
+ spmc_sp_synchronous_exit(&sp->ec[idx], x4);
+ /* Should not get here. */
+ panic();
+ }
+
+ return spmc_smc_return(smc_fid, secure_origin, x1, x2, x3, x4,
+ handle, cookie, flags, dst_id);
+}
+
/*******************************************************************************
* This function handles the FFA_MSG_WAIT SMC to allow an SP to relinquish its
* cycles.
@@ -602,6 +762,16 @@
{
switch (smc_fid) {
+ case FFA_MSG_SEND_DIRECT_REQ_SMC32:
+ case FFA_MSG_SEND_DIRECT_REQ_SMC64:
+ return direct_req_smc_handler(smc_fid, secure_origin, x1, x2,
+ x3, x4, cookie, handle, flags);
+
+ case FFA_MSG_SEND_DIRECT_RESP_SMC32:
+ case FFA_MSG_SEND_DIRECT_RESP_SMC64:
+ return direct_resp_smc_handler(smc_fid, secure_origin, x1, x2,
+ x3, x4, cookie, handle, flags);
+
case FFA_MSG_WAIT:
return msg_wait_handler(smc_fid, secure_origin, x1, x2, x3, x4,
cookie, handle, flags);