From 7f41bcc76d8857b4678c90796ebd85794ff3ee5f Mon Sep 17 00:00:00 2001
From: Zelalem Aweke <zelalem.aweke@arm.com>
Date: Wed, 3 Nov 2021 13:31:53 -0500
Subject: [PATCH] refactor(context mgmt): remove registers accessible only from
 secure state from EL2 context

The following registers are only accessible from secure state,
therefore don't need to be saved/restored during world switch.
 - SDER32_EL2
 - VSTCR_EL2
 - VSTTBR_EL2

This patch removes these registers from EL2 context.

Signed-off-by: Zelalem Aweke <zelalem.aweke@arm.com>
Change-Id: I24d08aacb1b6def261c7b37d3e1265bb76adafdc
---
 include/lib/el3_runtime/aarch64/context.h | 13 +++-----
 lib/el3_runtime/aarch64/context.S         | 38 -----------------------
 2 files changed, 5 insertions(+), 46 deletions(-)

diff --git a/include/lib/el3_runtime/aarch64/context.h b/include/lib/el3_runtime/aarch64/context.h
index d2d12e51d..3a09383a7 100644
--- a/include/lib/el3_runtime/aarch64/context.h
+++ b/include/lib/el3_runtime/aarch64/context.h
@@ -220,20 +220,17 @@
 #define CTX_TTBR1_EL2		U(0x1a0)
 #define CTX_VDISR_EL2		U(0x1a8)
 #define CTX_VSESR_EL2		U(0x1b0)
-#define CTX_VSTCR_EL2		U(0x1b8)
-#define CTX_VSTTBR_EL2		U(0x1c0)
-#define CTX_SDER32_EL2		U(0x1c8)
-#define CTX_VNCR_EL2		U(0x1d0)
-#define CTX_TRFCR_EL2		U(0x1d8)
+#define CTX_VNCR_EL2		U(0x1b8)
+#define CTX_TRFCR_EL2		U(0x1c0)
 
 // Starting with Armv8.5
-#define CTX_SCXTNUM_EL2		U(0x1e0)
+#define CTX_SCXTNUM_EL2		U(0x1c8)
 
 // Register for FEAT_HCX
-#define CTX_HCRX_EL2            U(0x1e8)
+#define CTX_HCRX_EL2            U(0x1d0)
 
 /* Align to the next 16 byte boundary */
-#define CTX_EL2_SYSREGS_END	U(0x1f0)
+#define CTX_EL2_SYSREGS_END	U(0x1e0)
 
 #endif /* CTX_INCLUDE_EL2_REGS */
 
diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S
index 0432d96b1..69acc2f9d 100644
--- a/lib/el3_runtime/aarch64/context.S
+++ b/lib/el3_runtime/aarch64/context.S
@@ -188,25 +188,6 @@ func el2_sysregs_context_save
 	stp	x11, x12, [x0, #CTX_VDISR_EL2]
 #endif /* RAS_EXTENSION */
 
-#if ENABLE_FEAT_SEL2
-	/*
-	 * VSTCR_EL2 and VSTTBR_EL2 registers are saved only
-	 * when FEAT_SEL2 is supported.
-	 */
-	mrs	x13, vstcr_el2
-	mrs	x14, vsttbr_el2
-	stp	x13, x14, [x0, #CTX_VSTCR_EL2]
-#endif /* ENABLE_FEAT_SEL2 */
-
-#if CTX_INCLUDE_AARCH32_REGS && ENABLE_FEAT_SEL2
-	/*
-	 * SDER32_EL2 register is saved only when EL2 and EL1
-	 * capable of using Aarch32 and FEAT_SEL2 is supported.
-	 */
-	mrs	x15, sder32_el2
-	str	x15, [x0, #CTX_SDER32_EL2]
-#endif /* CTX_INCLUDE_AARCH32_REGS && ENABLE_FEAT_SEL2 */
-
 #if CTX_INCLUDE_NEVE_REGS
 	/*
 	 * VNCR_EL2 register is saved only when FEAT_NV2 is supported.
@@ -401,25 +382,6 @@ func el2_sysregs_context_restore
 	msr	vsesr_el2, x12
 #endif /* RAS_EXTENSION */
 
-#if ENABLE_FEAT_SEL2
-	/*
-	 * VSTCR_EL2 and VSTTBR_EL2 registers are restored only when FEAT_SEL2
-	 * is supported.
-	 */
-	ldp	x13, x14, [x0, #CTX_VSTCR_EL2]
-	msr	vstcr_el2, x13
-	msr	vsttbr_el2, x14
-#endif /* ENABLE_FEAT_SEL2 */
-
-#if CTX_INCLUDE_AARCH32_REGS && ENABLE_FEAT_SEL2
-	/*
-	 * SDER32_EL2 register is restored only when EL2 and EL1 capable of using
-	 * Aarch32 and FEAT_SEL2 is supported.
-	 */
-	ldr	x15, [x0, #CTX_SDER32_EL2]
-	msr	sder32_el2, x15
-#endif /* CTX_INCLUDE_AARCH32_REGS && ENABLE_FEAT_SEL2 */
-
 #if CTX_INCLUDE_NEVE_REGS
 	/*
 	 * VNCR_EL2 register is restored only when FEAT_NV2 is supported.