xlat: Add support for EL0 and EL1 mappings

This patch introduces the ability of the xlat tables library to manage
EL0 and EL1 mappings from a higher exception level.

Attributes MT_USER and MT_PRIVILEGED have been added to allow the user
specify the target EL in the translation regime EL1&0.

REGISTER_XLAT_CONTEXT2 macro is introduced to allow creating a
xlat_ctx_t that targets a given translation regime (EL1&0 or EL3).

A new member is added to xlat_ctx_t to represent the translation regime
the xlat_ctx_t manages. The execute_never mask member is removed as it
is computed from existing information.

Change-Id: I95e14abc3371d7a6d6a358cc54c688aa9975c110
Co-authored-by: Douglas Raillard <douglas.raillard@arm.com>
Co-authored-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Co-authored-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

3 files changed, 68 insertions, 11 deletions

diff --git a/include/lib/xlat_tables/xlat_tables_defs.h b/include/lib/xlat_tables/xlat_tables_defs.h
index b0f5a04c9..7cb9d37f1 100644
--- a/include/lib/xlat_tables/xlat_tables_defs.h
+++ b/include/lib/xlat_tables/xlat_tables_defs.h
@@ -89,9 +89,22 @@
  * AP[1] bit is ignored by hardware and is
  * treated as if it is One in EL2/EL3
  */
-#define AP_RO				(U(0x1) << 5)
-#define AP_RW				(U(0x0) << 5)
+#define AP2_SHIFT			U(0x7)
+#define AP2_RO				U(0x1)
+#define AP2_RW				U(0x0)
 
+#define AP1_SHIFT			U(0x6)
+#define AP1_ACCESS_UNPRIVILEGED		U(0x1)
+#define AP1_NO_ACCESS_UNPRIVILEGED	U(0x0)
+
+/*
+ * The following definitions must all be passed to the LOWER_ATTRS() macro to
+ * get the right bitmask.
+ */
+#define AP_RO				(AP2_RO << 5)
+#define AP_RW				(AP2_RW << 5)
+#define AP_ACCESS_UNPRIVILEGED		(AP1_ACCESS_UNPRIVILEGED    << 4)
+#define AP_NO_ACCESS_UNPRIVILEGED	(AP1_NO_ACCESS_UNPRIVILEGED << 4)
 #define NS				(U(0x1) << 3)
 #define ATTR_NON_CACHEABLE_INDEX	U(0x2)
 #define ATTR_DEVICE_INDEX		U(0x1)
diff --git a/include/lib/xlat_tables/xlat_tables_v2.h b/include/lib/xlat_tables/xlat_tables_v2.h
index 2cc59f6d1..1a55fba77 100644
--- a/include/lib/xlat_tables/xlat_tables_v2.h
+++ b/include/lib/xlat_tables/xlat_tables_v2.h
@@ -57,6 +57,11 @@
 #define MT_SEC_SHIFT		U(4)
 /* Access permissions for instruction execution (EXECUTE/EXECUTE_NEVER) */
 #define MT_EXECUTE_SHIFT	U(5)
+/*
+ * In the EL1&0 translation regime, mark the region as User (EL0) or
+ * Privileged (EL1). In the EL3 translation regime this has no effect.
+ */
+#define MT_USER_SHIFT		U(6)
 /* All other bits are reserved */
 
 /*
@@ -89,10 +94,20 @@ typedef enum  {
 	 */
 	MT_EXECUTE		= U(0) << MT_EXECUTE_SHIFT,
 	MT_EXECUTE_NEVER	= U(1) << MT_EXECUTE_SHIFT,
+
+	/*
+	 * When mapping a region at EL0 or EL1, this attribute will be used to
+	 * determine if a User mapping (EL0) will be created or a Privileged
+	 * mapping (EL1).
+	 */
+	MT_USER				= U(1) << MT_USER_SHIFT,
+	MT_PRIVILEGED			= U(0) << MT_USER_SHIFT,
 } mmap_attr_t;
 
+/* Compound attributes for most common usages */
 #define MT_CODE		(MT_MEMORY | MT_RO | MT_EXECUTE)
 #define MT_RO_DATA	(MT_MEMORY | MT_RO | MT_EXECUTE_NEVER)
+#define MT_RW_DATA	(MT_MEMORY | MT_RW | MT_EXECUTE_NEVER)
 
 /*
  * Structure for specifying a single region of memory.
@@ -149,8 +164,25 @@ typedef struct xlat_ctx xlat_ctx_t;
  */
 #define REGISTER_XLAT_CONTEXT(_ctx_name, _mmap_count, _xlat_tables_count,	\
 			_virt_addr_space_size, _phy_addr_space_size)		\
-	_REGISTER_XLAT_CONTEXT(_ctx_name, _mmap_count, _xlat_tables_count,	\
-		_virt_addr_space_size, _phy_addr_space_size)
+	_REGISTER_XLAT_CONTEXT_FULL_SPEC(_ctx_name, _mmap_count,	\
+					 _xlat_tables_count,		\
+					 _virt_addr_space_size,		\
+					 _phy_addr_space_size,		\
+					 IMAGE_XLAT_DEFAULT_REGIME)
+
+/*
+ * Same as REGISTER_XLAT_CONTEXT plus the additional parameter _xlat_regime to
+ * specify the translation regime managed by this xlat_ctx_t instance. The
+ * values are the one from xlat_regime_t enumeration.
+ */
+#define REGISTER_XLAT_CONTEXT2(_ctx_name, _mmap_count, _xlat_tables_count,	\
+			_virt_addr_space_size, _phy_addr_space_size,		\
+			_xlat_regime)					\
+	_REGISTER_XLAT_CONTEXT_FULL_SPEC(_ctx_name, _mmap_count,	\
+					 _xlat_tables_count,		\
+					 _virt_addr_space_size,		\
+					 _phy_addr_space_size,		\
+					 _xlat_regime)
 
 /******************************************************************************
  * Generic translation table APIs.
diff --git a/include/lib/xlat_tables/xlat_tables_v2_helpers.h b/include/lib/xlat_tables/xlat_tables_v2_helpers.h
index 1ea2fc0ab..0ebdc9307 100644
--- a/include/lib/xlat_tables/xlat_tables_v2_helpers.h
+++ b/include/lib/xlat_tables/xlat_tables_v2_helpers.h
@@ -99,11 +99,12 @@ struct xlat_ctx {
 	unsigned int initialized;
 
 	/*
-	 * Bit mask that has to be ORed to the rest of a translation table
-	 * descriptor in order to prohibit execution of code at the exception
-	 * level of this translation context.
+	 * Translation regime managed by this xlat_ctx_t. It takes the values of
+	 * the enumeration xlat_regime_t. The type is "int" to avoid a circular
+	 * dependency on xlat_tables_v2.h, but this member must be treated as
+	 * xlat_regime_t.
 	 */
-	uint64_t execute_never_mask;
+	int xlat_regime;
 };
 
 #if PLAT_XLAT_TABLES_DYNAMIC
@@ -120,9 +121,9 @@ struct xlat_ctx {
 	/* do nothing */
 #endif /* PLAT_XLAT_TABLES_DYNAMIC */
 
-
-#define _REGISTER_XLAT_CONTEXT(_ctx_name, _mmap_count, _xlat_tables_count,	\
-			_virt_addr_space_size, _phy_addr_space_size)		\
+#define _REGISTER_XLAT_CONTEXT_FULL_SPEC(_ctx_name, _mmap_count, _xlat_tables_count,	\
+			_virt_addr_space_size, _phy_addr_space_size,		\
+			_xlat_regime)					\
 	CASSERT(CHECK_VIRT_ADDR_SPACE_SIZE(_virt_addr_space_size),		\
 		assert_invalid_virtual_addr_space_size_for_##_ctx_name);	\
 										\
@@ -154,12 +155,23 @@ struct xlat_ctx {
 		.tables = _ctx_name##_xlat_tables,				\
 		.tables_num = _xlat_tables_count,				\
 		 _REGISTER_DYNMAP_STRUCT(_ctx_name)				\
+		.xlat_regime = (_xlat_regime),					\
 		.max_pa = 0,							\
 		.max_va = 0,							\
 		.next_table = 0,						\
 		.initialized = 0,						\
 	}
 
+
+/* This IMAGE_EL macro must not to be used outside the library */
+#if IMAGE_BL1 || IMAGE_BL31
+# define IMAGE_EL	3
+# define IMAGE_XLAT_DEFAULT_REGIME EL3_REGIME
+#else
+# define IMAGE_EL	1
+# define IMAGE_XLAT_DEFAULT_REGIME EL1_EL0_REGIME
+#endif
+
 #endif /*__ASSEMBLY__*/
 
 #endif /* __XLAT_TABLES_V2_HELPERS_H__ */