stm32mp1: use last page of SYSRAM as SCMI shared memory

SCMI shared memory is used to exchange message payloads between
secure SCMI services and non-secure SCMI agents. It is mapped
uncached (device) mainly to conform to existing support in
the Linux kernel. Note that executive messages are mostly short
(few 32bit words) hence not using cache will not penalize much
performances.

Platform stm32mp1 shall configure ETZPC to harden properly the
secure and non-secure areas of the SYSRAM address space, that before
CPU accesses the shared memory when mapped non-secure.

This change defines STM32MP_SEC_SYSRAM_BASE/STM32MP_SEC_SYSRAM_SIZE and
STM32MP_NS_SYSRAM_BASE/STM32MP_NS_SYSRAM_SIZE.

Change-Id: I71ff02a359b9668ae1c5a71b5f102cf3d310f289
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>

plat/st/stm32mp1/sp_min/sp_min_setup.c

@@ -77,7 +77,25 @@ entry_point_info_t *sp_min_plat_get_bl33_ep_info(void)
 	return next_image_info;
 }
 
+CASSERT((STM32MP_SEC_SYSRAM_BASE == STM32MP_SYSRAM_BASE) &&
+	((STM32MP_SEC_SYSRAM_BASE + STM32MP_SEC_SYSRAM_SIZE) <=
+	 (STM32MP_SYSRAM_BASE + STM32MP_SYSRAM_SIZE)),
+	assert_secure_sysram_fits_at_begining_of_sysram);
+
+#ifdef STM32MP_NS_SYSRAM_BASE
+CASSERT((STM32MP_NS_SYSRAM_BASE >= STM32MP_SEC_SYSRAM_BASE) &&
+	((STM32MP_NS_SYSRAM_BASE + STM32MP_NS_SYSRAM_SIZE) ==
+	 (STM32MP_SYSRAM_BASE + STM32MP_SYSRAM_SIZE)),
+	assert_non_secure_sysram_fits_at_end_of_sysram);
+
+CASSERT((STM32MP_NS_SYSRAM_BASE & (PAGE_SIZE_4KB - U(1))) == 0U,
+	assert_non_secure_sysram_base_is_4kbyte_aligned);
+
+#define TZMA1_SECURE_RANGE \
+	(((STM32MP_NS_SYSRAM_BASE - STM32MP_SYSRAM_BASE) >> FOUR_KB_SHIFT) - 1U)
+#else
 #define TZMA1_SECURE_RANGE		STM32MP1_ETZPC_TZMA_ALL_SECURE
+#endif /* STM32MP_NS_SYSRAM_BASE */
 #define TZMA0_SECURE_RANGE		STM32MP1_ETZPC_TZMA_ALL_SECURE
 
 static void stm32mp1_etzpc_early_setup(void)

plat/st/stm32mp1/stm32mp1_def.h

@@ -56,6 +56,15 @@
 #define STM32MP_SYSRAM_BASE		U(0x2FFC0000)
 #define STM32MP_SYSRAM_SIZE		U(0x00040000)
 
+#define STM32MP_NS_SYSRAM_SIZE		PAGE_SIZE
+#define STM32MP_NS_SYSRAM_BASE		(STM32MP_SYSRAM_BASE + \
+					 STM32MP_SYSRAM_SIZE - \
+					 STM32MP_NS_SYSRAM_SIZE)
+
+#define STM32MP_SEC_SYSRAM_BASE		STM32MP_SYSRAM_BASE
+#define STM32MP_SEC_SYSRAM_SIZE		(STM32MP_SYSRAM_SIZE - \
+					 STM32MP_NS_SYSRAM_SIZE)
+
 /* DDR configuration */
 #define STM32MP_DDR_BASE		U(0xC0000000)
 #define STM32MP_DDR_MAX_SIZE		U(0x40000000)	/* Max 1GB */
@@ -81,18 +90,18 @@ enum ddr_type {
 /* 256 Octets reserved for header */
 #define STM32MP_HEADER_SIZE		U(0x00000100)
 
-#define STM32MP_BINARY_BASE		(STM32MP_SYSRAM_BASE +		\
+#define STM32MP_BINARY_BASE		(STM32MP_SEC_SYSRAM_BASE +	\
 					 STM32MP_PARAM_LOAD_SIZE +	\
 					 STM32MP_HEADER_SIZE)
 
-#define STM32MP_BINARY_SIZE		(STM32MP_SYSRAM_SIZE -		\
+#define STM32MP_BINARY_SIZE		(STM32MP_SEC_SYSRAM_SIZE -	\
 					 (STM32MP_PARAM_LOAD_SIZE +	\
 					  STM32MP_HEADER_SIZE))
 
 #ifdef AARCH32_SP_OPTEE
 #define STM32MP_BL32_SIZE		U(0)
 
-#define STM32MP_OPTEE_BASE		STM32MP_SYSRAM_BASE
+#define STM32MP_OPTEE_BASE		STM32MP_SEC_SYSRAM_BASE
 
 #define STM32MP_OPTEE_SIZE		(STM32MP_DTB_BASE -  \
 					 STM32MP_OPTEE_BASE)
@@ -104,8 +113,8 @@ enum ddr_type {
 #endif
 #endif
 
-#define STM32MP_BL32_BASE		(STM32MP_SYSRAM_BASE + \
-					 STM32MP_SYSRAM_SIZE - \
+#define STM32MP_BL32_BASE		(STM32MP_SEC_SYSRAM_BASE + \
+					 STM32MP_SEC_SYSRAM_SIZE - \
 					 STM32MP_BL32_SIZE)
 
 #ifdef AARCH32_SP_OPTEE

plat/st/stm32mp1/stm32mp1_private.c

@@ -30,12 +30,29 @@
 					 BOARD_ID_REVISION_SHIFT)
 #define BOARD_ID2BOM(_id)		((_id) & BOARD_ID_BOM_MASK)
 
-#define MAP_SRAM	MAP_REGION_FLAT(STM32MP_SYSRAM_BASE, \
+#if defined(IMAGE_BL2)
+#define MAP_SEC_SYSRAM	MAP_REGION_FLAT(STM32MP_SYSRAM_BASE, \
 					STM32MP_SYSRAM_SIZE, \
 					MT_MEMORY | \
 					MT_RW | \
 					MT_SECURE | \
 					MT_EXECUTE_NEVER)
+#elif defined(IMAGE_BL32)
+#define MAP_SEC_SYSRAM	MAP_REGION_FLAT(STM32MP_SEC_SYSRAM_BASE, \
+					STM32MP_SEC_SYSRAM_SIZE, \
+					MT_MEMORY | \
+					MT_RW | \
+					MT_SECURE | \
+					MT_EXECUTE_NEVER)
+
+/* Non-secure SYSRAM is used a uncached memory for SCMI message transfer */
+#define MAP_NS_SYSRAM	MAP_REGION_FLAT(STM32MP_NS_SYSRAM_BASE, \
+					STM32MP_NS_SYSRAM_SIZE, \
+					MT_DEVICE | \
+					MT_RW | \
+					MT_NS | \
+					MT_EXECUTE_NEVER)
+#endif
 
 #define MAP_DEVICE1	MAP_REGION_FLAT(STM32MP1_DEVICE1_BASE, \
 					STM32MP1_DEVICE1_SIZE, \
@@ -53,7 +70,7 @@
 
 #if defined(IMAGE_BL2)
 static const mmap_region_t stm32mp1_mmap[] = {
-	MAP_SRAM,
+	MAP_SEC_SYSRAM,
 	MAP_DEVICE1,
 	MAP_DEVICE2,
 	{0}
@@ -61,7 +78,8 @@ static const mmap_region_t stm32mp1_mmap[] = {
 #endif
 #if defined(IMAGE_BL32)
 static const mmap_region_t stm32mp1_mmap[] = {
-	MAP_SRAM,
+	MAP_SEC_SYSRAM,
+	MAP_NS_SYSRAM,
 	MAP_DEVICE1,
 	MAP_DEVICE2,
 	{0}