feat(cm): context switch MDCR_EL3 register

Currently MDCR_EL3 register value is same for all the
worlds(Non-secure, Secure, Realm and Root).

With this approach, features enable/disable settings
remain same across all the worlds. This is not ideal as
there must be flexibility in controlling feature as per
the requirements for individual world.

The patch addresses this by providing MDCR_EL3 a per world
value. Features with identical values for all the worlds are
grouped under ``manage_extensions_common`` API.

Change-Id: Ibc068d985fe165d8cb6d0ffb84119bffd743b3d1
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
diff --git a/lib/extensions/brbe/brbe.c b/lib/extensions/brbe/brbe.c
index 37bd834..dde0266 100644
--- a/lib/extensions/brbe/brbe.c
+++ b/lib/extensions/brbe/brbe.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022-2023, Arm Limited. All rights reserved.
+ * Copyright (c) 2022-2024, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,9 +9,10 @@
 #include <arch_helpers.h>
 #include <lib/extensions/brbe.h>
 
-void brbe_init_el3(void)
+void brbe_enable(cpu_context_t *ctx)
 {
-	uint64_t val;
+	el3_state_t *state = get_el3state_ctx(ctx);
+	u_register_t mdcr_el3_val = read_ctx_reg(state, CTX_MDCR_EL3);
 
 	/*
 	 * MDCR_EL3.SBRBE = 0b01
@@ -19,8 +20,7 @@
 	 * Allows BRBE usage in non-secure world and prohibited in
 	 * secure world.
 	 */
-	val = read_mdcr_el3();
-	val &= ~(MDCR_SBRBE_MASK << MDCR_SBRBE_SHIFT);
-	val |= (0x1UL << MDCR_SBRBE_SHIFT);
-	write_mdcr_el3(val);
+	mdcr_el3_val &= ~(MDCR_SBRBE_MASK << MDCR_SBRBE_SHIFT);
+	mdcr_el3_val |= (0x1UL << MDCR_SBRBE_SHIFT);
+	write_ctx_reg(state, CTX_MDCR_EL3, mdcr_el3_val);
 }
diff --git a/lib/extensions/spe/spe.c b/lib/extensions/spe/spe.c
index d1fb182..c6076fe 100644
--- a/lib/extensions/spe/spe.c
+++ b/lib/extensions/spe/spe.c
@@ -29,9 +29,10 @@
 	__asm__ volatile("hint #17");
 }
 
-void spe_init_el3(void)
+void spe_enable(cpu_context_t *ctx)
 {
-	uint64_t v;
+	el3_state_t *state = get_el3state_ctx(ctx);
+	u_register_t mdcr_el3_val = read_ctx_reg(state, CTX_MDCR_EL3);
 
 	/*
 	 * MDCR_EL3.NSPB (ARM v8.2): SPE enabled in Non-secure state
@@ -46,10 +47,9 @@
 	 * Setting this bit to 1 doesn't have any effect on it when
 	 * FEAT_SPEv1p2 not implemented.
 	 */
-	v = read_mdcr_el3();
-	v |= MDCR_NSPB(MDCR_NSPB_EL1) | MDCR_EnPMSN_BIT;
-	v &= ~(MDCR_NSPBE_BIT);
-	write_mdcr_el3(v);
+	mdcr_el3_val |= MDCR_NSPB(MDCR_NSPB_EL1) | MDCR_EnPMSN_BIT;
+	mdcr_el3_val &= ~(MDCR_NSPBE_BIT);
+	write_ctx_reg(state, CTX_MDCR_EL3, mdcr_el3_val);
 }
 
 void spe_init_el2_unused(void)
diff --git a/lib/extensions/trbe/trbe.c b/lib/extensions/trbe/trbe.c
index d4fbdfb..9157734 100644
--- a/lib/extensions/trbe/trbe.c
+++ b/lib/extensions/trbe/trbe.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021-2023, Arm Limited. All rights reserved.
+ * Copyright (c) 2021-2024, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -19,9 +19,10 @@
 	__asm__ volatile("hint #18");
 }
 
-void trbe_init_el3(void)
+void trbe_enable(cpu_context_t *ctx)
 {
-	u_register_t val;
+	el3_state_t *state = get_el3state_ctx(ctx);
+	u_register_t mdcr_el3_val = read_ctx_reg(state, CTX_MDCR_EL3);
 
 	/*
 	 * MDCR_EL3.NSTBE = 0b0
@@ -33,10 +34,9 @@
 	 *  NS-EL2, tracing is prohibited in Secure and Realm state (if
 	 *  implemented).
 	 */
-	val = read_mdcr_el3();
-	val |= MDCR_NSTB(MDCR_NSTB_EL1);
-	val &= ~(MDCR_NSTBE_BIT);
-	write_mdcr_el3(val);
+	mdcr_el3_val |= MDCR_NSTB(MDCR_NSTB_EL1);
+	mdcr_el3_val &= ~(MDCR_NSTBE_BIT);
+	write_ctx_reg(state, CTX_MDCR_EL3, mdcr_el3_val);
 }
 
 void trbe_init_el2_unused(void)
diff --git a/lib/extensions/trf/aarch64/trf.c b/lib/extensions/trf/aarch64/trf.c
index 83fbf85..d36853a 100644
--- a/lib/extensions/trf/aarch64/trf.c
+++ b/lib/extensions/trf/aarch64/trf.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021-2023, Arm Limited. All rights reserved.
+ * Copyright (c) 2021-2024, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,9 +9,10 @@
 #include <arch_helpers.h>
 #include <lib/extensions/trf.h>
 
-void trf_init_el3(void)
+void trf_enable(cpu_context_t *ctx)
 {
-	u_register_t val;
+	el3_state_t *state = get_el3state_ctx(ctx);
+	u_register_t mdcr_el3_val = read_ctx_reg(state, CTX_MDCR_EL3);
 
 	/*
 	 * MDCR_EL3.STE = b0
@@ -22,9 +23,8 @@
 	 * Allow access of trace filter control registers from NS-EL2
 	 * and NS-EL1 when NS-EL2 is implemented but not used
 	 */
-	val = read_mdcr_el3();
-	val &= ~(MDCR_STE_BIT | MDCR_TTRF_BIT);
-	write_mdcr_el3(val);
+	mdcr_el3_val &= ~(MDCR_STE_BIT | MDCR_TTRF_BIT);
+	write_ctx_reg(state, CTX_MDCR_EL3, mdcr_el3_val);
 }
 
 void trf_init_el2_unused(void)