feat(spmc): add support for FFA_MSG_WAIT
Handle an incoming call of FFA_MSG_WAIT from the secure world
and update the runtime state of the calling partition accordingly.
This ABI can be called in the following scenarios:
- Used by an SP to signal it has finished initializing.
- To resume the normal world after handling a secure interrupt
that interrupted the normal world.
- To relinquish control back to the normal world.
Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Change-Id: I929713a2280e8ec291b5b4e8f6d4b49df337228c
diff --git a/services/std_svc/spm/el3_spmc/spmc.h b/services/std_svc/spm/el3_spmc/spmc.h
index e891516..df0aa61 100644
--- a/services/std_svc/spm/el3_spmc/spmc.h
+++ b/services/std_svc/spm/el3_spmc/spmc.h
@@ -23,6 +23,8 @@
#define FFA_SWD_ID_LIMIT SPMD_DIRECT_MSG_ENDPOINT_ID - 1
#define FFA_SWD_ID_MASK 0x8000
+/* ID 0 is reserved for the normal world entity, (Hypervisor or OS Kernel). */
+#define FFA_NWD_ID U(0)
/* First ID is reserved for the SPMC */
#define FFA_SPMC_ID U(FFA_SWD_ID_BASE)
/* SP IDs are allocated after the SPMC ID */
diff --git a/services/std_svc/spm/el3_spmc/spmc_main.c b/services/std_svc/spm/el3_spmc/spmc_main.c
index 8470cf3..ccebcff 100644
--- a/services/std_svc/spm/el3_spmc/spmc_main.c
+++ b/services/std_svc/spm/el3_spmc/spmc_main.c
@@ -177,6 +177,85 @@
}
/*******************************************************************************
+ * FF-A ABI Handlers.
+ ******************************************************************************/
+/*******************************************************************************
+ * This function handles the FFA_MSG_WAIT SMC to allow an SP to relinquish its
+ * cycles.
+ ******************************************************************************/
+static uint64_t msg_wait_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)
+{
+ struct secure_partition_desc *sp;
+ unsigned int idx;
+
+ /*
+ * Check that the response did not originate from the Normal world as
+ * only the secure world can call this ABI.
+ */
+ if (!secure_origin) {
+ VERBOSE("Normal world cannot call FFA_MSG_WAIT.\n");
+ return spmc_ffa_error_return(handle, FFA_ERROR_NOT_SUPPORTED);
+ }
+
+ /* Get the descriptor of the SP that invoked FFA_MSG_WAIT. */
+ sp = spmc_get_current_sp_ctx();
+ if (sp == NULL) {
+ return spmc_ffa_error_return(handle,
+ FFA_ERROR_INVALID_PARAMETER);
+ }
+
+ /*
+ * Get the execution context of the SP that invoked FFA_MSG_WAIT.
+ */
+ idx = get_ec_index(sp);
+
+ /* Ensure SP execution context was in the right runtime model. */
+ if (sp->ec[idx].rt_model == RT_MODEL_DIR_REQ) {
+ return spmc_ffa_error_return(handle, FFA_ERROR_DENIED);
+ }
+
+ /* Sanity check the state is being tracked correctly in the SPMC. */
+ assert(sp->ec[idx].rt_state == RT_STATE_RUNNING);
+
+ /*
+ * Perform a synchronous exit if the partition was initialising. The
+ * state is updated after the exit.
+ */
+ if (sp->ec[idx].rt_model == RT_MODEL_INIT) {
+ spmc_sp_synchronous_exit(&sp->ec[idx], x4);
+ /* Should not get here */
+ panic();
+ }
+
+ /* Update the state of the SP execution context. */
+ sp->ec[idx].rt_state = RT_STATE_WAITING;
+
+ /* Resume normal world if a secure interrupt was handled. */
+ if (sp->ec[idx].rt_model == RT_MODEL_INTR) {
+ /* FFA_MSG_WAIT can only be called from the secure world. */
+ unsigned int secure_state_in = SECURE;
+ unsigned int secure_state_out = NON_SECURE;
+
+ cm_el1_sysregs_context_save(secure_state_in);
+ cm_el1_sysregs_context_restore(secure_state_out);
+ cm_set_next_eret_context(secure_state_out);
+ SMC_RET0(cm_get_context(secure_state_out));
+ }
+
+ /* Forward the response to the Normal world. */
+ return spmc_smc_return(smc_fid, secure_origin, x1, x2, x3, x4,
+ handle, cookie, flags, FFA_NWD_ID);
+}
+
+/*******************************************************************************
* This function will parse the Secure Partition Manifest. From manifest, it
* will fetch details for preparing Secure partition image context and secure
* partition image boot arguments if any.
@@ -481,6 +560,10 @@
{
switch (smc_fid) {
+ case FFA_MSG_WAIT:
+ return msg_wait_handler(smc_fid, secure_origin, x1, x2, x3, x4,
+ cookie, handle, flags);
+
default:
WARN("Unsupported FF-A call 0x%08x.\n", smc_fid);
break;