ARM64: XEN: Add a function to initialize Xen specific UEFI runtime services

When running on Xen hypervisor, runtime services are supported through
hypercall. Add a Xen specific function to initialize runtime services.
Signed-off-by: NShannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm/include/asm/xen/xen-ops.h

+#ifndef _ASM_XEN_OPS_H
+#define _ASM_XEN_OPS_H
+
+void xen_efi_runtime_setup(void);
+
+#endif /* _ASM_XEN_OPS_H */

arch/arm/xen/Makefile

 obj-y		:= enlighten.o hypercall.o grant-table.o p2m.o mm.o
+obj-$(CONFIG_XEN_EFI) += efi.o

arch/arm/xen/efi.c

+/*
+ * Copyright (c) 2015, Linaro Limited, Shannon Zhao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/efi.h>
+#include <xen/xen-ops.h>
+#include <asm/xen/xen-ops.h>
+
+/* Set XEN EFI runtime services function pointers. Other fields of struct efi,
+ * e.g. efi.systab, will be set like normal EFI.
+ */
+void __init xen_efi_runtime_setup(void)
+{
+	efi.get_time                 = xen_efi_get_time;
+	efi.set_time                 = xen_efi_set_time;
+	efi.get_wakeup_time          = xen_efi_get_wakeup_time;
+	efi.set_wakeup_time          = xen_efi_set_wakeup_time;
+	efi.get_variable             = xen_efi_get_variable;
+	efi.get_next_variable        = xen_efi_get_next_variable;
+	efi.set_variable             = xen_efi_set_variable;
+	efi.query_variable_info      = xen_efi_query_variable_info;
+	efi.update_capsule           = xen_efi_update_capsule;
+	efi.query_capsule_caps       = xen_efi_query_capsule_caps;
+	efi.get_next_high_mono_count = xen_efi_get_next_high_mono_count;
+	efi.reset_system             = NULL; /* Functionality provided by Xen. */
+}
+EXPORT_SYMBOL_GPL(xen_efi_runtime_setup);

arch/arm64/include/asm/xen/xen-ops.h

+#ifndef _ASM_XEN_OPS_H
+#define _ASM_XEN_OPS_H
+
+void xen_efi_runtime_setup(void);
+
+#endif /* _ASM_XEN_OPS_H */

arch/arm64/xen/Makefile

 xen-arm-y	+= $(addprefix ../../arm/xen/, enlighten.o grant-table.o p2m.o mm.o)
 obj-y		:= xen-arm.o hypercall.o
+obj-$(CONFIG_XEN_EFI) += $(addprefix ../../arm/xen/, efi.o)

drivers/xen/Kconfig

@@ -275,7 +275,7 @@ config XEN_HAVE_PVMMU
 
 config XEN_EFI
 	def_bool y
-	depends on X86_64 && EFI
+	depends on (ARM || ARM64 || X86_64) && EFI
 
 config XEN_AUTO_XLATE
 	def_bool y