mem_protect: Add mem_protect support in Juno and FVP for DRAM1

mem_protect needs some kind of non-volatile memory because it has
to remember its state across reset and power down events.
The most suitable electronic part for this feature is a NVRAM
which should be only accesible from the secure world. Juno and
FVP lack such hardware and for this reason the MEM_PROTECT
functionality is implemented with Flash EEPROM memory on both
boards, even though this memory is accesible from the non-secure
world. This is done only to show a full implementation of
these PSCI features, but an actual system shouldn't use a
non-secure NVRAM to implement it.

The EL3 runtime software will write the mem_protect flag and BL2
will read and clear the memory ranges if enabled. It is done in
BL2 because it reduces the time that TF needs access to the full
non-secure memory.

The memory layout of both boards is defined using macros which
take different values in Juno and FVP platforms. Generic platform
helpers are added that use the platform specific macros to generate
a mem_region_t that is valid for the platform.

Change-Id: I2c6818ac091a2966fa07a52c5ddf8f6fde4941e9
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

3 files changed, 22 insertions, 2 deletions

diff --git a/include/plat/arm/board/common/board_arm_def.h b/include/plat/arm/board/common/board_arm_def.h
index 751c3bb1..a065abf5 100644
--- a/include/plat/arm/board/common/board_arm_def.h
+++ b/include/plat/arm/board/common/board_arm_def.h
@@ -89,11 +89,26 @@
 
 #define PLAT_ARM_TRUSTED_SRAM_SIZE	0x00040000	/* 256 KB */
 
+/* Reserve the last block of flash for PSCI MEM PROTECT flag */
 #define PLAT_ARM_FIP_BASE		V2M_FLASH0_BASE
-#define PLAT_ARM_FIP_MAX_SIZE		V2M_FLASH0_SIZE
+#define PLAT_ARM_FIP_MAX_SIZE		(V2M_FLASH0_SIZE - V2M_FLASH_BLOCK_SIZE)
 
 #define PLAT_ARM_NVM_BASE		V2M_FLASH0_BASE
-#define PLAT_ARM_NVM_SIZE		V2M_FLASH0_SIZE
+#define PLAT_ARM_NVM_SIZE		(V2M_FLASH0_SIZE - V2M_FLASH_BLOCK_SIZE)
 
+/* PSCI memory protect definitions:
+ * This variable is stored in a non-secure flash because some ARM reference
+ * platforms do not have secure NVRAM. Real systems that provided MEM_PROTECT
+ * support must use a secure NVRAM to store the PSCI MEM_PROTECT definitions.
+ */
+#define PLAT_ARM_MEM_PROT_ADDR		(V2M_FLASH0_BASE + \
+					 V2M_FLASH0_SIZE - V2M_FLASH_BLOCK_SIZE)
+
+/*
+ * Map mem_protect flash region with read and write permissions
+ */
+#define ARM_V2M_MAP_MEM_PROTECT		MAP_REGION_FLAT(PLAT_ARM_MEM_PROT_ADDR,	\
+						V2M_FLASH_BLOCK_SIZE,		\
+						MT_DEVICE | MT_RW | MT_SECURE)
 
 #endif /* __BOARD_ARM_DEF_H__ */
diff --git a/include/plat/arm/board/common/v2m_def.h b/include/plat/arm/board/common/v2m_def.h
index 2ad513ac..364b7803 100644
--- a/include/plat/arm/board/common/v2m_def.h
+++ b/include/plat/arm/board/common/v2m_def.h
@@ -69,6 +69,7 @@
 /* NOR Flash */
 #define V2M_FLASH0_BASE			0x08000000
 #define V2M_FLASH0_SIZE			0x04000000
+#define V2M_FLASH_BLOCK_SIZE		0x00040000	/* 256 KB */
 
 #define V2M_IOFPGA_BASE			0x1c000000
 #define V2M_IOFPGA_SIZE			0x03000000
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index f0e97678..4e589c0c 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -122,6 +122,10 @@ int arm_validate_power_state(unsigned int power_state,
 int arm_validate_ns_entrypoint(uintptr_t entrypoint);
 void arm_system_pwr_domain_resume(void);
 void arm_program_trusted_mailbox(uintptr_t address);
+int arm_psci_read_mem_protect(int *val);
+int arm_nor_psci_write_mem_protect(int val);
+void arm_nor_psci_do_mem_protect(void);
+int arm_psci_mem_protect_chk(uintptr_t base, u_register_t length);
 
 /* Topology utility function */
 int arm_check_mpidr(u_register_t mpidr);