Add TZC function to configure region 0

Region 0 is special in TZC-400. It is possible to set the access
permissions for this but not the address range or filters to which
the permissions apply. Add a function for setting the region 0
access permissions.

Also add some VERBOSE logging and allow assembly files to include
the TZC header.

Change-Id: I4389261ba10a6e5e2e43ee93d55318dc507b6648

drivers/arm/tzc400/tzc400.c

 /*
- * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2015, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -191,15 +191,41 @@ void tzc_init(uint64_t base)
 			   BUILD_CONFIG_NR_MASK) + 1;
 }
 
+/*
+ * `tzc_configure_region0` is used to program region 0 into the TrustZone
+ * controller. Region 0 covers the whole address space that is not mapped
+ * to any other region, and is enabled on all filters; this cannot be
+ * changed. This function only changes the access permissions.
+ */
+void tzc_configure_region0(tzc_region_attributes_t sec_attr,
+			   uint32_t ns_device_access)
+{
+	assert(tzc.base);
+
+	VERBOSE("TZC : Configuring region 0 (sec_attr=0x%x, ns_devs=0x%x)\n",
+		sec_attr, ns_device_access);
+
+	assert(sec_attr <= TZC_REGION_S_RDWR);
+
+	/* Set secure attributes on region 0 */
+	tzc_write_region_attributes(tzc.base, 0,
+		sec_attr << REG_ATTR_SEC_SHIFT);
+
+	/*
+	 * Specify which non-secure devices have permission to access
+	 * region 0.
+	 */
+	tzc_write_region_id_access(tzc.base, 0, ns_device_access);
+}
+
 
 /*
  * `tzc_configure_region` is used to program regions into the TrustZone
  * controller. A region can be associated with more than one filter. The
  * associated filters are passed in as a bitmap (bit0 = filter0).
  * NOTE:
- * The region 0 covers the whole address space and is enabled on all filters,
- * this cannot be changed. It is, however, possible to change some region 0
- * permissions.
+ * Region 0 is special; it is preferable to use tzc_configure_region0
+ * for this region (see comment for that function).
  */
 void tzc_configure_region(uint32_t filters,
 			  uint8_t  region,
@@ -210,6 +236,13 @@ void tzc_configure_region(uint32_t filters,
 {
 	assert(tzc.base);
 
+	VERBOSE("TZC : Configuring region (filters=0x%x, region=%d, ...\n",
+		filters, region);
+	VERBOSE("TZC : ... base=0x%lx, top=0x%lx, ...\n",
+		region_base, region_top);
+	VERBOSE("TZC : ... sec_attr=0x%x, ns_devs=0x%x)\n",
+		sec_attr, ns_device_access);
+
 	/* Do range checks on filters and regions. */
 	assert(((filters >> tzc.num_filters) == 0) &&
 	       (region < tzc.num_regions));

include/drivers/arm/tzc400.h

 /*
- * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2015, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -31,7 +31,6 @@
 #ifndef __TZC400_H__
 #define __TZC400_H__
 
-#include <stdint.h>
 
 #define BUILD_CONFIG_OFF	0x000
 #define ACTION_OFF		0x004
@@ -148,9 +147,13 @@
 #define TZC_REGION_ACCESS_RDWR(id)					\
 		(TZC_REGION_ACCESS_RD(id) | TZC_REGION_ACCESS_WR(id))
 
-/* Filters are bit mapped 0 to 3. */
 #define TZC400_COMPONENT_ID	0xb105f00d
 
+
+#ifndef __ASSEMBLY__
+
+#include <stdint.h>
+
 /*******************************************************************************
  * Function & variable prototypes
  ******************************************************************************/
@@ -187,6 +190,8 @@ typedef enum {
 
 
 void tzc_init(uint64_t base);
+void tzc_configure_region0(tzc_region_attributes_t sec_attr,
+			uint32_t ns_device_access);
 void tzc_configure_region(uint32_t filters,
 			uint8_t region,
 			uint64_t region_base,
@@ -197,5 +202,6 @@ void tzc_enable_filters(void);
 void tzc_disable_filters(void);
 void tzc_set_action(tzc_action_t action);
 
+#endif /* __ASSEMBLY__ */
 
 #endif /* __TZC400__ */