arm/mpu: Map domain page in MPU systems

In MPU systems, we implement map_domain_page()/unmap_domain_page()
through mapping the domain page with a MPU region on demand.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Signed-off-by: Harry Ramsey <harry.ramsey@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>

xen/arch/arm/Kconfig

@@ -91,6 +91,7 @@ config MMU
 
 config MPU
 	bool "MPU" if UNSUPPORTED
+	select ARCH_MAP_DOMAIN_PAGE
 	select STATIC_MEMORY
 	help
 	  Memory Protection Unit (MPU). Select if you plan to run Xen on ARMv8-R

xen/arch/arm/mpu/Makefile

@@ -1,5 +1,6 @@
 obj-$(CONFIG_ARM_32) += arm32/
 obj-$(CONFIG_ARM_64) += arm64/
+obj-y += domain-page.o
 obj-y += mm.o
 obj-y += p2m.o
 obj-y += setup.init.o

xen/arch/arm/mpu/domain-page.c

@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <xen/bug.h>
+#include <xen/domain_page.h>
+#include <xen/mm.h>
+#include <xen/mm-frame.h>
+#include <xen/types.h>
+#include <xen/vmap.h>
+
+void *map_domain_page_global(mfn_t mfn)
+{
+    BUG_ON("unimplemented");
+    return NULL;
+}
+
+/* Map a page of domheap memory */
+void *map_domain_page(mfn_t mfn)
+{
+    return vmap_contig(mfn, 1);
+}
+
+/* Release a mapping taken with map_domain_page() */
+void unmap_domain_page(const void *ptr)
+{
+    vunmap(ptr);
+}
+
+mfn_t domain_page_map_to_mfn(const void *ptr)
+{
+    BUG_ON("unimplemented");
+    return INVALID_MFN;
+}
+
+void unmap_domain_page_global(const void *va)
+{
+    BUG_ON("unimplemented");
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */