Remove coherent memory from the BL memory maps

This patch extends the build option `USE_COHERENT_MEMORY` to
conditionally remove coherent memory from the memory maps of
all boot loader stages. The patch also adds necessary
documentation for coherent memory removal in firmware-design,
porting and user guides.

Fixes ARM-Software/tf-issues#106

Change-Id: I260e8768c6a5c2efc402f5804a80657d8ce38773

6 files changed, 87 insertions, 30 deletions

diff --git a/plat/juno/aarch64/juno_common.c b/plat/juno/aarch64/juno_common.c
index 8129b051..7ad40d0d 100644
--- a/plat/juno/aarch64/juno_common.c
+++ b/plat/juno/aarch64/juno_common.c
@@ -140,6 +140,7 @@ const unsigned int num_sec_irqs = sizeof(irq_sec_array) /
  * Macro generating the code for the function setting up the pagetables as per
  * the platform memory map & initialize the mmu, for the given exception level
  ******************************************************************************/
+#if USE_COHERENT_MEM
 #define DEFINE_CONFIGURE_MMU_EL(_el)				\
 	void configure_mmu_el##_el(unsigned long total_base,	\
 				  unsigned long total_size,	\
@@ -162,7 +163,25 @@ const unsigned int num_sec_irqs = sizeof(irq_sec_array) /
 								\
 	       enable_mmu_el##_el(0);				\
 	}
-
+#else
+#define DEFINE_CONFIGURE_MMU_EL(_el)				\
+	void configure_mmu_el##_el(unsigned long total_base,	\
+				  unsigned long total_size,	\
+				  unsigned long ro_start,	\
+				  unsigned long ro_limit)	\
+	{							\
+	       mmap_add_region(total_base, total_base,		\
+			       total_size,			\
+			       MT_MEMORY | MT_RW | MT_SECURE);	\
+	       mmap_add_region(ro_start, ro_start,		\
+			       ro_limit - ro_start,		\
+			       MT_MEMORY | MT_RO | MT_SECURE);	\
+	       mmap_add(juno_mmap);				\
+	       init_xlat_tables();				\
+								\
+	       enable_mmu_el##_el(0);				\
+	}
+#endif
 /* Define EL1 and EL3 variants of the function initialising the MMU */
 DEFINE_CONFIGURE_MMU_EL(1)
 DEFINE_CONFIGURE_MMU_EL(3)
diff --git a/plat/juno/bl1_plat_setup.c b/plat/juno/bl1_plat_setup.c
index e27e3948..23e8592b 100644
--- a/plat/juno/bl1_plat_setup.c
+++ b/plat/juno/bl1_plat_setup.c
@@ -41,6 +41,7 @@
 #include "juno_def.h"
 #include "juno_private.h"
 
+#if USE_COHERENT_MEM
 /*******************************************************************************
  * Declarations of linker defined symbols which will help us find the layout
  * of trusted RAM
@@ -57,6 +58,7 @@ extern unsigned long __COHERENT_RAM_END__;
  */
 #define BL1_COHERENT_RAM_BASE (unsigned long)(&__COHERENT_RAM_START__)
 #define BL1_COHERENT_RAM_LIMIT (unsigned long)(&__COHERENT_RAM_END__)
+#endif
 
 /* Data structure which holds the extents of the trusted RAM for BL1 */
 static meminfo_t bl1_tzram_layout;
@@ -189,9 +191,12 @@ void bl1_plat_arch_setup(void)
 	configure_mmu_el3(bl1_tzram_layout.total_base,
 			  bl1_tzram_layout.total_size,
 			  TZROM_BASE,
-			  TZROM_BASE + TZROM_SIZE,
-			  BL1_COHERENT_RAM_BASE,
-			  BL1_COHERENT_RAM_LIMIT);
+			  TZROM_BASE + TZROM_SIZE
+#if USE_COHERENT_MEM
+			  , BL1_COHERENT_RAM_BASE,
+			  BL1_COHERENT_RAM_LIMIT
+#endif
+			  );
 }
 
 /*******************************************************************************
diff --git a/plat/juno/bl2_plat_setup.c b/plat/juno/bl2_plat_setup.c
index 900a587f..8e7b2a0a 100644
--- a/plat/juno/bl2_plat_setup.c
+++ b/plat/juno/bl2_plat_setup.c
@@ -47,8 +47,10 @@
 extern unsigned long __RO_START__;
 extern unsigned long __RO_END__;
 
+#if USE_COHERENT_MEM
 extern unsigned long __COHERENT_RAM_START__;
 extern unsigned long __COHERENT_RAM_END__;
+#endif
 
 /*
  * The next 2 constants identify the extents of the code & RO data region.
@@ -59,6 +61,7 @@ extern unsigned long __COHERENT_RAM_END__;
 #define BL2_RO_BASE (unsigned long)(&__RO_START__)
 #define BL2_RO_LIMIT (unsigned long)(&__RO_END__)
 
+#if USE_COHERENT_MEM
 /*
  * The next 2 constants identify the extents of the coherent memory region.
  * These addresses are used by the MMU setup code and therefore they must be
@@ -68,11 +71,11 @@ extern unsigned long __COHERENT_RAM_END__;
  */
 #define BL2_COHERENT_RAM_BASE (unsigned long)(&__COHERENT_RAM_START__)
 #define BL2_COHERENT_RAM_LIMIT (unsigned long)(&__COHERENT_RAM_END__)
+#endif
 
 /* Data structure which holds the extents of the trusted RAM for BL2 */
 static meminfo_t bl2_tzram_layout
-__attribute__ ((aligned(PLATFORM_CACHE_LINE_SIZE),
-		section("tzfw_coherent_mem")));
+__attribute__ ((aligned(PLATFORM_CACHE_LINE_SIZE)));
 
 /*******************************************************************************
  * Structure which holds the arguments which need to be passed to BL3-1
@@ -194,9 +197,12 @@ void bl2_plat_arch_setup(void)
 	configure_mmu_el1(bl2_tzram_layout.total_base,
 			  bl2_tzram_layout.total_size,
 			  BL2_RO_BASE,
-			  BL2_RO_LIMIT,
-			  BL2_COHERENT_RAM_BASE,
-			  BL2_COHERENT_RAM_LIMIT);
+			  BL2_RO_LIMIT
+#if USE_COHERENT_MEM
+			  , BL2_COHERENT_RAM_BASE,
+			  BL2_COHERENT_RAM_LIMIT
+#endif
+			  );
 }
 
 /*******************************************************************************
diff --git a/plat/juno/bl31_plat_setup.c b/plat/juno/bl31_plat_setup.c
index c4504622..ad8ea435 100644
--- a/plat/juno/bl31_plat_setup.c
+++ b/plat/juno/bl31_plat_setup.c
@@ -48,19 +48,25 @@
  ******************************************************************************/
 extern unsigned long __RO_START__;
 extern unsigned long __RO_END__;
+extern unsigned long __BL31_END__;
 
+#if USE_COHERENT_MEM
 extern unsigned long __COHERENT_RAM_START__;
 extern unsigned long __COHERENT_RAM_END__;
+#endif
 
 /*
- * The next 2 constants identify the extents of the code & RO data region.
- * These addresses are used by the MMU setup code and therefore they must be
- * page-aligned.  It is the responsibility of the linker script to ensure that
- * __RO_START__ and __RO_END__ linker symbols refer to page-aligned addresses.
+ * The next 3 constants identify the extents of the code, RO data region and the
+ * limit of the BL3-1 image.  These addresses are used by the MMU setup code and
+ * therefore they must be page-aligned.  It is the responsibility of the linker
+ * script to ensure that __RO_START__, __RO_END__ & __BL31_END__ linker symbols
+ * refer to page-aligned addresses.
  */
 #define BL31_RO_BASE (unsigned long)(&__RO_START__)
 #define BL31_RO_LIMIT (unsigned long)(&__RO_END__)
+#define BL31_END (unsigned long)(&__BL31_END__)
 
+#if USE_COHERENT_MEM
 /*
  * The next 2 constants identify the extents of the coherent memory region.
  * These addresses are used by the MMU setup code and therefore they must be
@@ -70,6 +76,7 @@ extern unsigned long __COHERENT_RAM_END__;
  */
 #define BL31_COHERENT_RAM_BASE (unsigned long)(&__COHERENT_RAM_START__)
 #define BL31_COHERENT_RAM_LIMIT (unsigned long)(&__COHERENT_RAM_END__)
+#endif
 
 /******************************************************************************
  * Placeholder variables for copying the arguments that have been passed to
@@ -178,9 +185,13 @@ void bl31_platform_setup(void)
 void bl31_plat_arch_setup()
 {
 	configure_mmu_el3(BL31_RO_BASE,
-			  BL31_COHERENT_RAM_LIMIT - BL31_RO_BASE,
+			  (BL31_END - BL31_RO_BASE),
 			  BL31_RO_BASE,
-			  BL31_RO_LIMIT,
+			  BL31_RO_LIMIT
+#if USE_COHERENT_MEM
+			  ,
 			  BL31_COHERENT_RAM_BASE,
-			  BL31_COHERENT_RAM_LIMIT);
+			  BL31_COHERENT_RAM_LIMIT
+#endif
+			  );
 }
diff --git a/plat/juno/juno_private.h b/plat/juno/juno_private.h
index b7ef4488..70439e8b 100644
--- a/plat/juno/juno_private.h
+++ b/plat/juno/juno_private.h
@@ -134,15 +134,21 @@ unsigned int platform_get_core_pos(unsigned long mpidr);
 void configure_mmu_el1(unsigned long total_base,
 		       unsigned long total_size,
 		       unsigned long ro_start,
-		       unsigned long ro_limit,
-		       unsigned long coh_start,
-		       unsigned long coh_limit);
+		       unsigned long ro_limit
+#if USE_COHERENT_MEM
+		       , unsigned long coh_start,
+		       unsigned long coh_limit
+#endif
+		       );
 void configure_mmu_el3(unsigned long total_base,
 		       unsigned long total_size,
 		       unsigned long ro_start,
-		       unsigned long ro_limit,
-		       unsigned long coh_start,
-		       unsigned long coh_limit);
+		       unsigned long ro_limit
+#if USE_COHERENT_MEM
+		       , unsigned long coh_start,
+		       unsigned long coh_limit
+#endif
+		       );
 void plat_report_exception(unsigned long type);
 unsigned long plat_get_ns_image_entrypoint(void);
 unsigned long platform_get_stack(unsigned long mpidr);
diff --git a/plat/juno/tsp/tsp_plat_setup.c b/plat/juno/tsp/tsp_plat_setup.c
index 0a9d4cbe..8293a132 100644
--- a/plat/juno/tsp/tsp_plat_setup.c
+++ b/plat/juno/tsp/tsp_plat_setup.c
@@ -40,19 +40,25 @@
  ******************************************************************************/
 extern unsigned long __RO_START__;
 extern unsigned long __RO_END__;
+extern unsigned long __BL32_END__;
 
+#if USE_COHERENT_MEM
 extern unsigned long __COHERENT_RAM_START__;
 extern unsigned long __COHERENT_RAM_END__;
+#endif
 
 /*
- * The next 2 constants identify the extents of the code & RO data region.
- * These addresses are used by the MMU setup code and therefore they must be
- * page-aligned.  It is the responsibility of the linker script to ensure that
- * __RO_START__ and __RO_END__ linker symbols refer to page-aligned addresses.
+ * The next 3 constants identify the extents of the code, RO data region and the
+ * limit of the BL3-2 image.  These addresses are used by the MMU setup code and
+ * therefore they must be page-aligned.  It is the responsibility of the linker
+ * script to ensure that __RO_START__, __RO_END__ & __BL32_END__ linker symbols
+ * refer to page-aligned addresses.
  */
 #define BL32_RO_BASE (unsigned long)(&__RO_START__)
 #define BL32_RO_LIMIT (unsigned long)(&__RO_END__)
+#define BL32_END (unsigned long)(&__BL32_END__)
 
+#if USE_COHERENT_MEM
 /*
  * The next 2 constants identify the extents of the coherent memory region.
  * These addresses are used by the MMU setup code and therefore they must be
@@ -62,6 +68,7 @@ extern unsigned long __COHERENT_RAM_END__;
  */
 #define BL32_COHERENT_RAM_BASE (unsigned long)(&__COHERENT_RAM_START__)
 #define BL32_COHERENT_RAM_LIMIT (unsigned long)(&__COHERENT_RAM_END__)
+#endif
 
 /*******************************************************************************
  * Initialize the UART
@@ -90,9 +97,12 @@ void tsp_platform_setup(void)
 void tsp_plat_arch_setup(void)
 {
 	configure_mmu_el1(BL32_RO_BASE,
-			  BL32_COHERENT_RAM_LIMIT - BL32_RO_BASE,
+			  (BL32_END - BL32_RO_BASE),
 			  BL32_RO_BASE,
-			  BL32_RO_LIMIT,
-			  BL32_COHERENT_RAM_BASE,
-			  BL32_COHERENT_RAM_LIMIT);
+			  BL32_RO_LIMIT
+#if USE_COHERENT_MEM
+			  , BL32_COHERENT_RAM_BASE,
+			  BL32_COHERENT_RAM_LIMIT
+#endif
+			  );
 }