Non-Secure Interrupt support during Standard SMC processing in TSP

Implements support for Non Secure Interrupts preempting the
Standard SMC call in EL1. Whenever an IRQ is trapped in the
Secure world we securely handover to the Normal world
to process the interrupt. The normal world then issues
"resume" smc call to resume the previous interrupted SMC call.
Fixes ARM-software/tf-issues#105

Change-Id: I72b760617dee27438754cdfc9fe9bcf4cc024858

1 files changed, 20 insertions, 0 deletions

diff --git a/services/spd/tspd/tspd_private.h b/services/spd/tspd/tspd_private.h
index b9cf496d..7395bb9e 100644
--- a/services/spd/tspd/tspd_private.h
+++ b/services/spd/tspd/tspd_private.h
@@ -125,6 +125,12 @@
 #include <cassert.h>
 #include <stdint.h>
 
+/*
+ * The number of arguments to save during a SMC call for TSP.
+ * Currently only x1 and x2 are used by TSP.
+ */
+#define TSP_NUM_ARGS	0x2
+
 /* AArch64 callee saved general purpose register context structure. */
 DEFINE_REG_STRUCT(c_rt_regs, TSPD_C_RT_CTX_ENTRIES);
 
@@ -147,6 +153,8 @@ CASSERT(TSPD_C_RT_CTX_SIZE == sizeof(c_rt_regs_t),	\
  * 'c_rt_ctx'       - stack address to restore C runtime context from after
  *                    returning from a synchronous entry into the SP.
  * 'cpu_ctx'        - space to maintain SP architectural state
+ * 'saved_tsp_args' - space to store arguments for TSP arithmetic operations
+ *                    which will queried using the TSP_GET_ARGS SMC by TSP.
  ******************************************************************************/
 typedef struct tsp_context {
 	uint64_t saved_elr_el3;
@@ -155,8 +163,20 @@ typedef struct tsp_context {
 	uint64_t mpidr;
 	uint64_t c_rt_ctx;
 	cpu_context_t cpu_ctx;
+	uint64_t saved_tsp_args[TSP_NUM_ARGS];
 } tsp_context_t;
 
+/* Helper macros to store and retrieve tsp args from tsp_context */
+#define store_tsp_args(tsp_ctx, x1, x2)		do {\
+				tsp_ctx->saved_tsp_args[0] = x1;\
+				tsp_ctx->saved_tsp_args[1] = x2;\
+			} while (0)
+
+#define get_tsp_args(tsp_ctx, x1, x2)	do {\
+				x1 = tsp_ctx->saved_tsp_args[0];\
+				x2 = tsp_ctx->saved_tsp_args[1];\
+			} while (0)
+
 /* TSPD power management handlers */
 extern const spd_pm_ops_t tspd_pm;