Add support for pointer authentication

The previous commit added the infrastructure to load and save
ARMv8.3-PAuth registers during Non-secure <-> Secure world switches, but
didn't actually enable pointer authentication in the firmware.

This patch adds the functionality needed for platforms to provide
authentication keys for the firmware, and a new option (ENABLE_PAUTH) to
enable pointer authentication in the firmware itself. This option is
disabled by default, and it requires CTX_INCLUDE_PAUTH_REGS to be
enabled.

Change-Id: I35127ec271e1198d43209044de39fa712ef202a5
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index da8b6e4..495ecb3 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -23,6 +23,23 @@
 		ID_AA64MMFR2_EL1_CNP_MASK) != 0U;
 }
 
+static inline bool is_armv8_3_pauth_present(void)
+{
+	uint64_t mask = (ID_AA64ISAR1_GPI_MASK << ID_AA64ISAR1_GPI_SHIFT) |
+			(ID_AA64ISAR1_GPA_MASK << ID_AA64ISAR1_GPA_SHIFT) |
+			(ID_AA64ISAR1_API_MASK << ID_AA64ISAR1_API_SHIFT) |
+			(ID_AA64ISAR1_APA_MASK << ID_AA64ISAR1_APA_SHIFT);
+
+	/* If any of the fields is not zero, PAuth is present */
+	return (read_id_aa64isar1_el1() & mask) != 0U;
+}
+
+static inline bool is_armv8_3_pauth_api_present(void)
+{
+	return ((read_id_aa64isar1_el1() >> ID_AA64ISAR1_API_SHIFT) &
+		ID_AA64ISAR1_API_MASK) != 0U;
+}
+
 static inline bool is_armv8_4_ttst_present(void)
 {
 	return ((read_id_aa64mmfr2_el1() >> ID_AA64MMFR2_EL1_ST_SHIFT) &
diff --git a/include/arch/aarch64/arch_helpers.h b/include/arch/aarch64/arch_helpers.h
index 4e459bb..e07db30 100644
--- a/include/arch/aarch64/arch_helpers.h
+++ b/include/arch/aarch64/arch_helpers.h
@@ -454,7 +454,8 @@
 DEFINE_RENAME_SYSREG_READ_FUNC(id_aa64mmfr2_el1, ID_AA64MMFR2_EL1)
 
 /* Armv8.3 Pointer Authentication Registers */
-DEFINE_RENAME_SYSREG_RW_FUNCS(apgakeylo_el1, APGAKeyLo_EL1)
+DEFINE_RENAME_SYSREG_RW_FUNCS(apiakeyhi_el1, APIAKeyHi_EL1)
+DEFINE_RENAME_SYSREG_RW_FUNCS(apiakeylo_el1, APIAKeyLo_EL1)
 
 #define IS_IN_EL(x) \
 	(GET_EL(read_CurrentEl()) == MODE_EL##x)
diff --git a/include/common/bl_common.h b/include/common/bl_common.h
index fd7656eb..9817ec7 100644
--- a/include/common/bl_common.h
+++ b/include/common/bl_common.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -207,6 +207,8 @@
 void setup_page_tables(const struct mmap_region *bl_regions,
 			   const struct mmap_region *plat_regions);
 
+void bl_handle_pauth(void);
+
 #endif /*__ASSEMBLY__*/
 
 #endif /* BL_COMMON_H */
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index 13767ff..4832e49 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -104,6 +104,7 @@
 void bl2_plat_preload_setup(void);
 int plat_try_next_boot_source(void);
 int plat_get_mbedtls_heap(void **heap_addr, size_t *heap_size);
+uint64_t *plat_init_apiakey(void);
 
 /*******************************************************************************
  * Mandatory BL1 functions