From c4ab278688dda7ca9ddbe92f7f2fcc29eb03ec77 Mon Sep 17 00:00:00 2001
From: Dmytro Firsov <dmytro_firsov@epam.com>
Date: Fri, 2 Jul 2021 10:26:29 +0300
Subject: [PATCH] arm64: xenvm: Add Xen hypercall interface for arm64

This commit adds Xen hypervisor call interface for arm64 architecture.
This is needed for further development of Xen features in Zephyr.

Signed-off-by: Dmytro Firsov <dmytro_firsov@epam.com>
---
 arch/arm64/core/CMakeLists.txt     |  2 ++
 arch/arm64/core/xen/CMakeLists.txt | 10 ++++++++++
 arch/arm64/core/xen/hypercall.S    | 26 ++++++++++++++++++++++++++
 include/arch/arm64/hypercall.h     | 12 ++++++++++++
 4 files changed, 50 insertions(+)
 create mode 100644 arch/arm64/core/xen/CMakeLists.txt
 create mode 100644 arch/arm64/core/xen/hypercall.S
 create mode 100644 include/arch/arm64/hypercall.h

diff --git a/arch/arm64/core/CMakeLists.txt b/arch/arm64/core/CMakeLists.txt
index 84013f2b5b6..1a0a5337bf8 100644
--- a/arch/arm64/core/CMakeLists.txt
+++ b/arch/arm64/core/CMakeLists.txt
@@ -30,3 +30,5 @@ if ((CONFIG_MP_NUM_CPUS GREATER 1) OR (CONFIG_SMP))
 endif ()
 
 zephyr_cc_option_ifdef(CONFIG_USERSPACE -mno-outline-atomics)
+
+add_subdirectory_ifdef(CONFIG_SOC_XENVM xen)
diff --git a/arch/arm64/core/xen/CMakeLists.txt b/arch/arm64/core/xen/CMakeLists.txt
new file mode 100644
index 00000000000..1009e655e69
--- /dev/null
+++ b/arch/arm64/core/xen/CMakeLists.txt
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (c) 2021 EPAM Systems
+
+# Needed to separate definitions in common Xen headers
+zephyr_compile_options($<$<COMPILE_LANGUAGE:ASM>:-D__ASSEMBLY__>)
+
+# Xen interface version used in headers for correct definition
+zephyr_compile_options(-D__XEN_INTERFACE_VERSION__=0x00040e00)
+
+zephyr_library_sources(hypercall.S)
diff --git a/arch/arm64/core/xen/hypercall.S b/arch/arm64/core/xen/hypercall.S
new file mode 100644
index 00000000000..a9abdb003e0
--- /dev/null
+++ b/arch/arm64/core/xen/hypercall.S
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2021 EPAM Systems
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <toolchain.h>
+#include <linker/sections.h>
+#include <xen/public/arch-arm.h>
+#include <xen/public/xen.h>
+
+#define HYPERCALL(hypercall)			\
+GTEXT(HYPERVISOR_##hypercall);			\
+SECTION_FUNC(TEXT, HYPERVISOR_##hypercall)	\
+	mov x16, #__HYPERVISOR_##hypercall;	\
+	hvc XEN_HYPERCALL_TAG;			\
+	ret;
+
+_ASM_FILE_PROLOGUE
+
+HYPERCALL(console_io);
+HYPERCALL(grant_table_op);
+HYPERCALL(sched_op);
+HYPERCALL(event_channel_op);
+HYPERCALL(hvm_op);
+HYPERCALL(memory_op);
diff --git a/include/arch/arm64/hypercall.h b/include/arch/arm64/hypercall.h
new file mode 100644
index 00000000000..6fefdff12b0
--- /dev/null
+++ b/include/arch/arm64/hypercall.h
@@ -0,0 +1,12 @@
+/*
+ * Copyright (c() 2021 EPAM Systems
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/* defined in hypercall.S by HYPERCALL(hypercall) */
+int HYPERVISOR_console_io(int op, int cnt, char *str);
+int HYPERVISOR_sched_op(int op, void *param);
+int HYPERVISOR_event_channel_op(int op, void *param);
+int HYPERVISOR_hvm_op(int op, void *param);
+int HYPERVISOR_memory_op(int op, void *param);