feat(cpu): add library support for Hunter ELP

Add basic CPU library code to support the Hunter ELP CPU in TF-A.
Hunter-ELP adds v9.2 architecture support and is derived from
Makalu-ELP. As such, the library code is adapted from the
Makalu-ELP support library.

Change-Id: I7e93b9af6b1f0bc4d08c3cf5caf071d2cbdbc89f
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>

include/lib/cpus/aarch64/cortex_hunter_elp_arm.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef CORTEX_HUNTER_ELP_ARM_H
+#define CORTEX_HUNTER_ELP_ARM_H
+
+#define CORTEX_HUNTER_ELP_ARM_MIDR					U(0x410FD821)
+
+/* Cortex Hunter ELP loop count for CVE-2022-23960 mitigation */
+#define CORTEX_HUNTER_ELP_ARM_BHB_LOOP_COUNT				U(132)
+
+/*******************************************************************************
+ * CPU Extended Control register specific definitions
+ ******************************************************************************/
+#define CORTEX_HUNTER_ELP_ARM_CPUECTLR_EL1				S3_0_C15_C1_4
+
+/*******************************************************************************
+ * CPU Power Control register specific definitions
+ ******************************************************************************/
+#define CORTEX_HUNTER_ELP_ARM_CPUPWRCTLR_EL1				S3_0_C15_C2_7
+#define CORTEX_HUNTER_ELP_ARM_CPUPWRCTLR_EL1_CORE_PWRDN_BIT		U(1)
+
+#endif /* CORTEX_HUNTER_ELP_ARM_H */

lib/cpus/aarch64/cortex_hunter_elp_arm.S

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <asm_macros.S>
+#include <common/bl_common.h>
+#include <cortex_hunter_elp_arm.h>
+#include <cpu_macros.S>
+#include <plat_macros.S>
+#include "wa_cve_2022_23960_bhb_vector.S"
+
+/* Hardware handled coherency */
+#if HW_ASSISTED_COHERENCY == 0
+#error "Cortex Hunter ELP must be compiled with HW_ASSISTED_COHERENCY enabled"
+#endif
+
+/* 64-bit only core */
+#if CTX_INCLUDE_AARCH32_REGS == 1
+#error "Cortex Hunter ELP supports only AArch64. Compile with CTX_INCLUDE_AARCH32_REGS=0"
+#endif
+
+#if WORKAROUND_CVE_2022_23960
+        wa_cve_2022_23960_bhb_vector_table CORTEX_HUNTER_ELP_ARM_BHB_LOOP_COUNT, cortex_hunter_elp_arm
+#endif /* WORKAROUND_CVE_2022_23960 */
+
+func check_errata_cve_2022_23960
+#if WORKAROUND_CVE_2022_23960
+	mov	x0, #ERRATA_APPLIES
+#else
+	mov	x0, #ERRATA_MISSING
+#endif
+	ret
+endfunc check_errata_cve_2022_23960
+
+func cortex_hunter_elp_arm_reset_func
+	/* Disable speculative loads */
+	msr	SSBS, xzr
+
+#if IMAGE_BL31 && WORKAROUND_CVE_2022_23960
+	/*
+	 * The Cortex Hunter ELP generic vectors are overridden to apply errata
+	 * mitigation on exception entry from lower ELs.
+	 */
+	adr	x0, wa_cve_vbar_cortex_hunter_elp_arm
+	msr	vbar_el3, x0
+#endif /* IMAGE_BL31 && WORKAROUND_CVE_2022_23960 */
+
+	isb
+	ret
+endfunc cortex_hunter_elp_arm_reset_func
+
+	/* ----------------------------------------------------
+	 * HW will do the cache maintenance while powering down
+	 * ----------------------------------------------------
+	 */
+func cortex_hunter_elp_arm_core_pwr_dwn
+	/* ---------------------------------------------------
+	 * Enable CPU power down bit in power control register
+	 * ---------------------------------------------------
+	 */
+	mrs	x0, CORTEX_HUNTER_ELP_ARM_CPUPWRCTLR_EL1
+	orr	x0, x0, #CORTEX_HUNTER_ELP_ARM_CPUPWRCTLR_EL1_CORE_PWRDN_BIT
+	msr	CORTEX_HUNTER_ELP_ARM_CPUPWRCTLR_EL1, x0
+	isb
+	ret
+endfunc cortex_hunter_elp_arm_core_pwr_dwn
+
+#if REPORT_ERRATA
+/*
+ * Errata printing function for Cortex Hunter ELP. Must follow AAPCS.
+ */
+func cortex_hunter_elp_arm_errata_report
+	stp	x8, x30, [sp, #-16]!
+
+	bl	cpu_get_rev_var
+	mov	x8, x0
+
+	/*
+	 * Report all errata. The revision-variant information is passed to
+	 * checking functions of each errata.
+	 */
+	report_errata WORKAROUND_CVE_2022_23960, cortex_hunter_elp_arm, cve_2022_23960
+
+	ldp	x8, x30, [sp], #16
+	ret
+endfunc cortex_hunter_elp_arm_errata_report
+#endif
+
+	/* ---------------------------------------------
+	 * This function provides Cortex Hunter ELP-specific
+	 * register information for crash reporting.
+	 * It needs to return with x6 pointing to
+	 * a list of register names in ascii and
+	 * x8 - x15 having values of registers to be
+	 * reported.
+	 * ---------------------------------------------
+	 */
+.section .rodata.cortex_hunter_elp_arm_regs, "aS"
+cortex_hunter_elp_arm_regs:  /* The ascii list of register names to be reported */
+	.asciz	"cpuectlr_el1", ""
+
+func cortex_hunter_elp_arm_cpu_reg_dump
+	adr	x6, cortex_hunter_elp_arm_regs
+	mrs	x8, CORTEX_HUNTER_ELP_ARM_CPUECTLR_EL1
+	ret
+endfunc cortex_hunter_elp_arm_cpu_reg_dump
+
+declare_cpu_ops cortex_hunter_elp_arm, CORTEX_HUNTER_ELP_ARM_MIDR, \
+	cortex_hunter_elp_arm_reset_func, \
+	cortex_hunter_elp_arm_core_pwr_dwn

plat/arm/board/fvp/platform.mk

@@ -143,6 +143,7 @@ else
 					lib/cpus/aarch64/cortex_a78c.S		\
 					lib/cpus/aarch64/cortex_hayes.S		\
 					lib/cpus/aarch64/cortex_hunter.S	\
+					lib/cpus/aarch64/cortex_hunter_elp_arm.S \
 					lib/cpus/aarch64/cortex_x2.S		\
 					lib/cpus/aarch64/neoverse_poseidon.S
 	endif

plat/arm/board/tc/platform.mk

@@ -80,7 +80,8 @@ endif
 # CPU libraries for TARGET_PLATFORM=2
 ifeq (${TARGET_PLATFORM}, 2)
 TC_CPU_SOURCES	+=	lib/cpus/aarch64/cortex_hayes.S \
-			lib/cpus/aarch64/cortex_hunter.S
+			lib/cpus/aarch64/cortex_hunter.S \
+			lib/cpus/aarch64/cortex_hunter_elp_arm.S
 endif
 
 INTERCONNECT_SOURCES	:=	${TC_BASE}/tc_interconnect.c