fconf: Add mbedtls shared heap as property

Use the firmware configuration framework in arm dynamic configuration
to retrieve mbedtls heap information between bl1 and bl2.

For this, a new fconf getter is added to expose the device tree base
address and size.

Change-Id: Ifa5ac9366ae100e2cdd1f4c8e85fc591b170f4b6
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>

include/lib/fconf/fconf_tbbr_getter.h

@@ -16,6 +16,8 @@
 
 struct tbbr_dyn_config_t {
 	uint32_t disable_auth;
+	void *mbedtls_heap_addr;
+	size_t mbedtls_heap_size;
 };
 
 extern struct tbbr_dyn_config_t tbbr_dyn_config;

include/plat/arm/common/arm_dyn_cfg_helpers.h

@@ -11,8 +11,6 @@
 
 /* Function declarations */
 int arm_dyn_tb_fw_cfg_init(void *dtb, int *node);
-int arm_get_dtb_mbedtls_heap_info(void *dtb, void **heap_addr,
-	size_t *heap_size);
 int arm_set_dtb_mbedtls_heap_info(void *dtb, void *heap_addr,
 	size_t heap_size);
 

lib/fconf/fconf_tbbr_getter.c

@@ -47,8 +47,27 @@ int fconf_populate_tbbr_dyn_config(uintptr_t config)
 		dyn_disable_auth();
 #endif
 
+	/* Retrieve the Mbed TLS heap details from the DTB */
+	err = fdtw_read_cells(dtb, node,
+		"mbedtls_heap_addr", 2, &tbbr_dyn_config.mbedtls_heap_addr);
+	if (err < 0) {
+		ERROR("FCONF: Read cell failed for mbedtls_heap\n");
+		return err;
+	}
+
+	err = fdtw_read_cells(dtb, node,
+		"mbedtls_heap_size", 1, &tbbr_dyn_config.mbedtls_heap_size);
+	if (err < 0) {
+		ERROR("FCONF: Read cell failed for mbedtls_heap\n");
+		return err;
+	}
+
 	VERBOSE("FCONF:tbbr.disable_auth cell found with value = %d\n",
 					tbbr_dyn_config.disable_auth);
+	VERBOSE("FCONF:tbbr.mbedtls_heap_addr cell found with value = %p\n",
+					tbbr_dyn_config.mbedtls_heap_addr);
+	VERBOSE("FCONF:tbbr.mbedtls_heap_size cell found with value = %zu\n",
+					tbbr_dyn_config.mbedtls_heap_size);
 
 	return 0;
 }

plat/arm/common/arm_dyn_cfg.c

@@ -18,6 +18,7 @@
 #endif
 #include <lib/fconf/fconf.h>
 #include <lib/fconf/fconf_dyn_cfg_getter.h>
+#include <lib/fconf/fconf_tbbr_getter.h>
 #include <plat/arm/common/arm_dyn_cfg_helpers.h>
 #include <plat/arm/common/plat_arm.h>
 #include <plat/common/platform.h>
@@ -56,24 +57,10 @@ int arm_get_mbedtls_heap(void **heap_addr, size_t *heap_size)
 
 #elif defined(IMAGE_BL2)
 
-	int err;
-	void *tb_fw_cfg_dtb;
-
-	/* fconf FW_CONFIG and TB_FW_CONFIG are currently the same DTB*/
-	tb_fw_cfg_dtb = (void *)FCONF_GET_PROPERTY(fconf, dtb, base_addr);
-
 	/* If in BL2, retrieve the already allocated heap's info from DTB */
-	if (tb_fw_cfg_dtb != NULL) {
-		err = arm_get_dtb_mbedtls_heap_info(tb_fw_cfg_dtb, heap_addr,
-			heap_size);
-		if (err < 0) {
-			ERROR("BL2: unable to retrieve shared Mbed TLS heap information from DTB\n");
-			panic();
-		}
-	} else {
-		ERROR("BL2: DTB missing, cannot get Mbed TLS heap\n");
-		panic();
-	}
+	*heap_addr = FCONF_GET_PROPERTY(tbbr, dyn_config, mbedtls_heap_addr);
+	*heap_size = FCONF_GET_PROPERTY(tbbr, dyn_config, mbedtls_heap_size);
+
 #endif
 
 	return 0;

plat/arm/common/arm_dyn_cfg_helpers.c

@@ -46,47 +46,6 @@ int arm_dyn_tb_fw_cfg_init(void *dtb, int *node)
 	return 0;
 }
 
-/*
- * Reads and returns the Mbed TLS shared heap information from the DTB.
- * This function is supposed to be called *only* when a DTB is present.
- * This function is supposed to be called only by BL2.
- *
- * Returns:
- *	0 = success
- *	-1 = error. In this case the values of heap_addr, heap_size should be
- *	    considered as garbage by the caller.
- */
-int arm_get_dtb_mbedtls_heap_info(void *dtb, void **heap_addr,
-	size_t *heap_size)
-{
-	int err, dtb_root;
-
-	/* Verify the DTB is valid and get the root node */
-	err = arm_dyn_tb_fw_cfg_init(dtb, &dtb_root);
-	if (err < 0) {
-		ERROR("Invalid TB_FW_CONFIG. Cannot retrieve Mbed TLS heap information from DTB\n");
-		return -1;
-	}
-
-	/* Retrieve the Mbed TLS heap details from the DTB */
-	err = fdtw_read_cells(dtb, dtb_root,
-		DTB_PROP_MBEDTLS_HEAP_ADDR, 2, heap_addr);
-	if (err < 0) {
-		ERROR("Error while reading %s from DTB\n",
-			DTB_PROP_MBEDTLS_HEAP_ADDR);
-		return -1;
-	}
-	err = fdtw_read_cells(dtb, dtb_root,
-		DTB_PROP_MBEDTLS_HEAP_SIZE, 1, heap_size);
-	if (err < 0) {
-		ERROR("Error while reading %s from DTB\n",
-			DTB_PROP_MBEDTLS_HEAP_SIZE);
-		return -1;
-	}
-	return 0;
-}
-
-
 /*
  * This function writes the Mbed TLS heap address and size in the DTB. When it
  * is called, it is guaranteed that a DTB is available. However it is not