Abort preempted TSP STD SMC after PSCI CPU suspend
Standard SMC requests that are handled in the secure-world by the Secure
Payload can be preempted by interrupts that must be handled in the
normal world. When the TSP is preempted the secure context is stored and
control is passed to the normal world to handle the non-secure
interrupt. Once completed the preempted secure context is restored. When
restoring the preempted context, the dispatcher assumes that the TSP
preempted context is still stored as the SECURE context by the context
management library.
However, PSCI power management operations causes synchronous entry into
TSP. This overwrites the preempted SECURE context in the context
management library. When restoring back the SECURE context, the Secure
Payload crashes because this context is not the preempted context
anymore.
This patch avoids corruption of the preempted SECURE context by aborting
any preempted SMC during PSCI power management calls. The
abort_std_smc_entry hook of the TSP is called when aborting the SMC
request.
It also exposes this feature as a FAST SMC callable from normal world to
abort preempted SMC with FID TSP_FID_ABORT.
Change-Id: I7a70347e9293f47d87b5de20484b4ffefb56b770
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
diff --git a/include/bl32/tsp/tsp.h b/include/bl32/tsp/tsp.h
index 4d7bc23..1e35788 100644
--- a/include/bl32/tsp/tsp.h
+++ b/include/bl32/tsp/tsp.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
@@ -41,6 +41,7 @@
#define TSP_SUSPEND_DONE 0xf2000003
#define TSP_RESUME_DONE 0xf2000004
#define TSP_PREEMPTED 0xf2000005
+#define TSP_ABORT_DONE 0xf2000007
#define TSP_SYSTEM_OFF_DONE 0xf2000008
#define TSP_SYSTEM_RESET_DONE 0xf2000009
@@ -81,10 +82,17 @@
/* SMC function ID to request a previously preempted std smc */
#define TSP_FID_RESUME TSP_STD_FID(0x3000)
/*
+ * SMC function ID to request abortion of a previously preempted std smc. A
+ * fast SMC is used so that the TSP abort handler does not have to be
+ * reentrant.
+ */
+#define TSP_FID_ABORT TSP_FAST_FID(0x3001)
+
+/*
* Total number of function IDs implemented for services offered to NS clients.
* The function IDs are defined above
*/
-#define TSP_NUM_FID 0x4
+#define TSP_NUM_FID 0x5
/* TSP implementation version numbers */
#define TSP_VERSION_MAJOR 0x0 /* Major version */
@@ -117,6 +125,7 @@
tsp_vector_isn_t sel1_intr_entry;
tsp_vector_isn_t system_off_entry;
tsp_vector_isn_t system_reset_entry;
+ tsp_vector_isn_t abort_std_smc_entry;
} tsp_vectors_t;