chore: fvp_r:  Initial No-EL3 and MPU Implementation

For v8-R64, especially R82, creating code to run BL1 at EL2, using MPU.

Signed-off-by: Gary Morrison <gary.morrison@arm.com>
Change-Id: I439ac3915b982ad1e61d24365bdd1584b3070425
diff --git a/lib/xlat_mpu/aarch64/enable_mpu.S b/lib/xlat_mpu/aarch64/enable_mpu.S
new file mode 100644
index 0000000..3791f2d
--- /dev/null
+++ b/lib/xlat_mpu/aarch64/enable_mpu.S
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <asm_macros.S>
+#include <assert_macros.S>
+#include <lib/xlat_tables/xlat_tables_v2.h>
+#include <platform_def.h>
+
+	.global	enable_mpu_direct_el2
+
+	/* void enable_mmu_direct_el2(unsigned int flags) */
+func enable_mpu_direct_el2
+#if ENABLE_ASSERTIONS
+	mrs	x1, sctlr_el2
+	tst	x1, #SCTLR_M_BIT
+	ASM_ASSERT(eq)
+#endif
+	mov	x7, x0
+	adrp	x0, mmu_cfg_params
+	add	x0, x0, :lo12:mmu_cfg_params
+
+	/* (MAIRs are already set up) */
+
+	/* TCR */
+	ldr	x2, [x0, #(MMU_CFG_TCR << 3)]
+	msr	tcr_el2, x2
+
+	/*
+	 * Ensure all translation table writes have drained into memory, the TLB
+	 * invalidation is complete, and translation register writes are
+	 * committed before enabling the MMU
+	 */
+	dsb	ish
+	isb
+
+	/* Set and clear required fields of SCTLR */
+	mrs	x4, sctlr_el2
+	mov_imm	x5, SCTLR_WXN_BIT | SCTLR_C_BIT | SCTLR_M_BIT
+	orr	x4, x4, x5
+
+	/* Additionally, amend SCTLR fields based on flags */
+	bic	x5, x4, #SCTLR_C_BIT
+	tst	x7, #DISABLE_DCACHE
+	csel	x4, x5, x4, ne
+
+	msr	sctlr_el2, x4
+	isb
+
+	ret
+endfunc enable_mpu_direct_el2
diff --git a/lib/xlat_mpu/aarch64/xlat_mpu_arch.c b/lib/xlat_mpu/aarch64/xlat_mpu_arch.c
new file mode 100644
index 0000000..5068eb8
--- /dev/null
+++ b/lib/xlat_mpu/aarch64/xlat_mpu_arch.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "../xlat_mpu_private.h"
+#include <arch.h>
+#include <arch_features.h>
+#include <lib/cassert.h>
+#include <lib/utils_def.h>
+#include <lib/xlat_tables/xlat_tables_v2.h>
+
+#include <fvp_r_arch_helpers.h>
+
+#warning "xlat_mpu library is currently experimental and its API may change in future."
+
+#if ENABLE_ASSERTIONS
+/*
+ * Return minimum virtual address space size supported by the architecture
+ */
+uintptr_t xlat_get_min_virt_addr_space_size(void)
+{
+	uintptr_t ret;
+
+	if (is_armv8_4_ttst_present()) {
+		ret = MIN_VIRT_ADDR_SPACE_SIZE_TTST;
+	} else {
+		ret = MIN_VIRT_ADDR_SPACE_SIZE;
+	}
+	return ret;
+}
+#endif /* ENABLE_ASSERTIONS*/
+
+bool is_mpu_enabled_ctx(const xlat_ctx_t *ctx)
+{
+	if (ctx->xlat_regime == EL1_EL0_REGIME) {
+		assert(xlat_arch_current_el() >= 1U);
+		return (read_sctlr_el1() & SCTLR_M_BIT) != 0U;
+	} else {
+		assert(xlat_arch_current_el() >= 2U);
+		return (read_sctlr_el2() & SCTLR_M_BIT) != 0U;
+	}
+}
+
+bool is_dcache_enabled(void)
+{
+	unsigned int el = get_current_el();
+
+	if (el == 1U) {
+		return (read_sctlr_el1() & SCTLR_C_BIT) != 0U;
+	} else {  /* must be EL2 */
+		return (read_sctlr_el2() & SCTLR_C_BIT) != 0U;
+	}
+}
+
+unsigned int xlat_arch_current_el(void)
+{
+	unsigned int el = (unsigned int)GET_EL(read_CurrentEl());
+
+	assert(el > 0U);
+
+	return el;
+}
+