fconf: enhancements to firmware configuration framework

A populate() function essentially captures the value of a property,
defined by a platform, into a fconf related c structure. Such a
callback is usually platform specific and is associated to a specific
configuration source.
For example, a populate() function which captures the hardware topology
of the platform can only parse HW_CONFIG DTB. Hence each populator
function must be registered with a specific 'config_type' identifier.
It broadly represents a logical grouping of configuration properties
which is usually a device tree source file.

Example:
> TB_FW: properties related to trusted firmware such as IO policies,
	 base address of other DTBs, mbedtls heap info etc.
> HW_CONFIG: properties related to hardware configuration of the SoC
	 such as topology, GIC controller, PSCI hooks, CPU ID etc.

This patch modifies FCONF_REGISTER_POPULATOR macro and fconf_populate()
to register and invoke the appropriate callbacks selectively based on
configuration type.

Change-Id: I6f63b1fd7a8729c6c9137d5b63270af1857bb44a
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

include/lib/fconf/fconf.h

@@ -12,9 +12,16 @@
 /* Public API */
 #define FCONF_GET_PROPERTY(a, b, c)	a##__##b##_getter(c)
 
-#define FCONF_REGISTER_POPULATOR(name, callback)				\
+/*
+ * This macro takes three arguments:
+ *   config:	Configuration identifier
+ *   name:	property namespace
+ *   callback:	populate() function
+ */
+#define FCONF_REGISTER_POPULATOR(config, name, callback)			\
 	__attribute__((used, section(".fconf_populator")))			\
 	const struct fconf_populator (name##__populator) = {			\
+		.config_type = (#config),					\
 		.info = (#name),						\
 		.populate = (callback)						\
 	};
@@ -27,6 +34,7 @@
  */
 struct fconf_populator {
 	/* Description of the data loaded by the callback */
+	const char *config_type;
 	const char *info;
 
 	/* Callback used by fconf_populate function with a provided config dtb.
@@ -45,7 +53,7 @@ void fconf_load_config(void);
  *
  *  Panic on error.
  */
-void fconf_populate(uintptr_t config);
+void fconf_populate(const char *config_type, uintptr_t config);
 
 /* FCONF specific getter */
 #define fconf__dtb_getter(prop)	fconf_dtb_info.prop

lib/fconf/fconf.c

@@ -53,17 +53,17 @@ void fconf_load_config(void)
 	INFO("FCONF: FW_CONFIG loaded at address = 0x%lx\n", arm_tb_fw_info.image_base);
 }
 
-void fconf_populate(uintptr_t config)
+void fconf_populate(const char *config_type, uintptr_t config)
 {
 	assert(config != 0UL);
 
 	/* Check if the pointer to DTB is correct */
 	if (fdt_check_header((void *)config) != 0) {
-		ERROR("FCONF: Invalid DTB file passed for FW_CONFIG\n");
+		ERROR("FCONF: Invalid DTB file passed for %s\n", config_type);
 		panic();
 	}
 
-	INFO("FCONF: Reading firmware configuration file from: 0x%lx\n", config);
+	INFO("FCONF: Reading %s firmware configuration file from: 0x%lx\n", config_type, config);
 
 	/* Go through all registered populate functions */
 	IMPORT_SYM(struct fconf_populator *, __FCONF_POPULATOR_START__, start);
@@ -73,12 +73,14 @@ void fconf_populate(uintptr_t config)
 	for (populator = start; populator != end; populator++) {
 		assert((populator->info != NULL) && (populator->populate != NULL));
 
+		if (strcmp(populator->config_type, config_type) == 0) {
 			INFO("FCONF: Reading firmware configuration information for: %s\n", populator->info);
 			if (populator->populate(config) != 0) {
 				/* TODO: handle property miss */
 				panic();
 			}
 		}
+	}
 
 	/* save local pointer to the config dtb */
 	fconf_dtb_info.base_addr = config;

lib/fconf/fconf_dyn_cfg_getter.c

@@ -92,4 +92,4 @@ int fconf_populate_dtb_registry(uintptr_t config)
 	return 0;
 }
 
-FCONF_REGISTER_POPULATOR(dyn_cfg, fconf_populate_dtb_registry);
+FCONF_REGISTER_POPULATOR(TB_FW, dyn_cfg, fconf_populate_dtb_registry);

lib/fconf/fconf_tbbr_getter.c

@@ -72,4 +72,4 @@ int fconf_populate_tbbr_dyn_config(uintptr_t config)
 	return 0;
 }
 
-FCONF_REGISTER_POPULATOR(tbbr, fconf_populate_tbbr_dyn_config);
+FCONF_REGISTER_POPULATOR(TB_FW, tbbr, fconf_populate_tbbr_dyn_config);

plat/arm/common/arm_bl2_setup.c

@@ -61,7 +61,7 @@ void arm_bl2_early_platform_setup(uintptr_t tb_fw_config,
 
 	/* Fill the properties struct with the info from the config dtb */
 	if (tb_fw_config != 0U) {
-		fconf_populate(tb_fw_config);
+		fconf_populate("TB_FW", tb_fw_config);
 	}
 
 	/* Initialise the IO layer and register platform IO devices */

plat/arm/common/fconf/arm_fconf_io.c

@@ -138,6 +138,6 @@ int fconf_populate_arm_io_policies(uintptr_t config)
 	return 0;
 }
 
-FCONF_REGISTER_POPULATOR(arm_io, fconf_populate_arm_io_policies);
+FCONF_REGISTER_POPULATOR(TB_FW, arm_io, fconf_populate_arm_io_policies);
 
 #endif /* IMAGE_BL2 */

plat/arm/common/fconf/arm_fconf_sp.c

@@ -102,6 +102,6 @@ int fconf_populate_arm_sp(uintptr_t config)
 	return 0;
 }
 
-FCONF_REGISTER_POPULATOR(arm_sp, fconf_populate_arm_sp);
+FCONF_REGISTER_POPULATOR(TB_FW, arm_sp, fconf_populate_arm_sp);
 
 #endif /* IMAGE_BL2 */