Refactor Statistical Profiling Extensions implementation

Factor out SPE operations in a separate file.  Use the publish
subscribe framework to drain the SPE buffers before entering secure
world.  Additionally, enable SPE before entering normal world.

A side effect of this change is that the profiling buffers are now
only drained when a transition from normal world to secure world
happens.  Previously they were drained also on return from secure
world, which is unnecessary as SPE is not supported in S-EL1.

Change-Id: I17582c689b4b525770dbb6db098b3a0b5777b70a
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index 479acc9..8f1523f 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -15,6 +15,7 @@
 #include <platform_def.h>
 #include <pubsub_events.h>
 #include <smcc_helpers.h>
+#include <spe.h>
 #include <string.h>
 #include <utils.h>
 
@@ -216,6 +217,9 @@
 static void enable_extensions_nonsecure(int el2_unused)
 {
 #if IMAGE_BL31
+#if ENABLE_SPE_FOR_LOWER_ELS
+	spe_enable(el2_unused);
+#endif
 #endif
 }
 
@@ -354,13 +358,6 @@
 			 * relying on hw. Some fields are architecturally
 			 * UNKNOWN on reset.
 			 *
-			 * MDCR_EL2.TPMS (ARM v8.2): Do not trap statistical
-			 * profiling controls to EL2.
-			 *
-			 * MDCR_EL2.E2PB (ARM v8.2): SPE enabled in non-secure
-			 * state. Accesses to profiling buffer controls at
-			 * non-secure EL1 are not trapped to EL2.
-			 *
 			 * MDCR_EL2.TDRA: Set to zero so that Non-secure EL0 and
 			 *  EL1 System register accesses to the Debug ROM
 			 *  registers are not trapped to EL2.
@@ -397,22 +394,6 @@
 					| MDCR_EL2_HPME_BIT | MDCR_EL2_TPM_BIT
 					| MDCR_EL2_TPMCR_BIT));
 
-#if ENABLE_SPE_FOR_LOWER_ELS
-			uint64_t id_aa64dfr0_el1;
-
-			/* Detect if SPE is implemented */
-			id_aa64dfr0_el1 = read_id_aa64dfr0_el1() >>
-				ID_AA64DFR0_PMS_SHIFT;
-			if ((id_aa64dfr0_el1 & ID_AA64DFR0_PMS_MASK) == 1) {
-				/*
-				 * Make sure traps to EL2 are not generated if
-				 * EL2 is implemented but not used.
-				 */
-				mdcr_el2 &= ~MDCR_EL2_TPMS;
-				mdcr_el2 |= MDCR_EL2_E2PB(MDCR_EL2_E2PB_EL1);
-			}
-#endif
-
 			write_mdcr_el2(mdcr_el2);
 
 			/*
@@ -454,7 +435,6 @@
 	assert(ctx);
 
 	el1_sysregs_context_save(get_sysregs_ctx(ctx));
-	el1_sysregs_context_save_post_ops();
 
 #if IMAGE_BL31
 	if (security_state == SECURE)