aarch64: mmu: Add initial support for memory domains

Introduce the basic support code for memory domains. To each domain
is associated a top page table which is a copy of the global kernel
one. When a partition is added, corresponding memory range is made
private before its mapping is adjusted.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>

include/arch/arm/aarch64/arch.h

@@ -41,6 +41,8 @@ extern "C" {
 
 #ifndef _ASMLANGUAGE
 
+#include <sys/slist.h>
+
 /* Kernel macros for memory attribution
  * (access permissions and cache-ability).
  *
@@ -69,6 +71,11 @@ typedef struct {
 	uint32_t attrs;
 } k_mem_partition_attr_t;
 
+struct arch_mem_domain {
+	struct arm_mmu_ptables ptables;
+	sys_snode_t node;
+};
+
 #endif /* _ASMLANGUAGE */
 
 #ifdef __cplusplus

include/arch/arm/aarch64/thread.h

@@ -41,6 +41,7 @@ typedef struct _callee_saved _callee_saved_t;
 
 struct _thread_arch {
 #ifdef CONFIG_USERSPACE
+	struct arm_mmu_ptables *ptables;
 	uint64_t priv_stack_start;
 #endif
 };