Remove variables from .data section

Update code base to remove variables from the .data section,
mainly by using const static data where possible and adding
the const specifier as required. Most changes are to the IO
subsystem, including the framework APIs. The FVP power
management code is also affected.

Delay initialization of the global static variable,
next_image_type in bl31_main.c, until it is realy needed.
Doing this moves the variable from the .data to the .bss
section.

Also review the IO interface for inconsistencies, using
uintptr_t where possible instead of void *. Remove the
io_handle and io_dev_handle typedefs, which were
unnecessary, replacing instances with uintptr_t.

Fixes ARM-software/tf-issues#107.

Change-Id: I085a62197c82410b566e4698e5590063563ed304

3 files changed, 67 insertions, 61 deletions

diff --git a/drivers/io/io_fip.c b/drivers/io/io_fip.c
index b2dcfcc..4848a70 100644
--- a/drivers/io/io_fip.c
+++ b/drivers/io/io_fip.c
@@ -62,7 +62,7 @@ typedef struct {
 	fip_toc_entry_t entry;
 } file_state_t;
 
-static plat_fip_name_uuid_t name_uuid[] = {
+static const plat_fip_name_uuid_t name_uuid[] = {
 	{BL2_IMAGE_NAME, UUID_TRUSTED_BOOT_FIRMWARE_BL2},
 	{BL31_IMAGE_NAME, UUID_EL3_RUNTIME_FIRMWARE_BL31},
 	{BL32_IMAGE_NAME, UUID_SECURE_PAYLOAD_BL32},
@@ -71,19 +71,19 @@ static plat_fip_name_uuid_t name_uuid[] = {
 
 static const uuid_t uuid_null = {0};
 static file_state_t current_file = {0};
-static io_dev_handle backend_dev_handle;
-static void *backend_image_spec;
+static uintptr_t backend_dev_handle;
+static uintptr_t backend_image_spec;
 
 
 /* Firmware Image Package driver functions */
-static int fip_dev_open(void *spec, io_dev_info_t **dev_info);
-static int fip_file_open(io_dev_info_t *dev_info, const void *spec,
+static int fip_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info);
+static int fip_file_open(io_dev_info_t *dev_info, const uintptr_t spec,
 			  io_entity_t *entity);
 static int fip_file_len(io_entity_t *entity, size_t *length);
-static int fip_file_read(io_entity_t *entity, void *buffer, size_t length,
+static int fip_file_read(io_entity_t *entity, uintptr_t buffer, size_t length,
 			  size_t *length_read);
 static int fip_file_close(io_entity_t *entity);
-static int fip_dev_init(io_dev_info_t *dev_info, const void *init_params);
+static int fip_dev_init(io_dev_info_t *dev_info, const uintptr_t init_params);
 static int fip_dev_close(io_dev_info_t *dev_info);
 
 
@@ -135,12 +135,12 @@ io_type_t device_type_fip(void)
 }
 
 
-static struct io_dev_connector fip_dev_connector = {
+static const io_dev_connector_t fip_dev_connector = {
 	.dev_open = fip_dev_open
 };
 
 
-static struct io_dev_funcs fip_dev_funcs = {
+static const io_dev_funcs_t fip_dev_funcs = {
 	.type = device_type_fip,
 	.open = fip_file_open,
 	.seek = NULL,
@@ -153,29 +153,30 @@ static struct io_dev_funcs fip_dev_funcs = {
 };
 
 
-static struct io_dev_info fip_dev_info = {
+/* No state associated with this device so structure can be const */
+static const io_dev_info_t fip_dev_info = {
 	.funcs = &fip_dev_funcs,
 	.info = (uintptr_t)NULL
 };
 
 
 /* Open a connection to the FIP device */
-static int fip_dev_open(void *spec __attribute__((unused)),
+static int fip_dev_open(const uintptr_t dev_spec __attribute__((unused)),
 			 io_dev_info_t **dev_info)
 {
 	assert(dev_info != NULL);
-	*dev_info = &fip_dev_info;
+	*dev_info = (io_dev_info_t *)&fip_dev_info; /* cast away const */
 
 	return IO_SUCCESS;
 }
 
 
 /* Do some basic package checks. */
-static int fip_dev_init(io_dev_info_t *dev_info, const void *init_params)
+static int fip_dev_init(io_dev_info_t *dev_info, const uintptr_t init_params)
 {
 	int result = IO_FAIL;
 	char *image_name = (char *)init_params;
-	io_handle backend_handle;
+	uintptr_t backend_handle;
 	fip_toc_header_t header;
 	size_t bytes_read;
 
@@ -198,7 +199,8 @@ static int fip_dev_init(io_dev_info_t *dev_info, const void *init_params)
 		goto fip_dev_init_exit;
 	}
 
-	result = io_read(backend_handle, &header, sizeof(header), &bytes_read);
+	result = io_read(backend_handle, (uintptr_t)&header, sizeof(header),
+			&bytes_read);
 	if (result == IO_SUCCESS) {
 		if (!is_valid_header(&header)) {
 			WARN("Firmware Image Package header check failed.\n");
@@ -220,19 +222,19 @@ static int fip_dev_close(io_dev_info_t *dev_info)
 	/* TODO: Consider tracking open files and cleaning them up here */
 
 	/* Clear the backend. */
-	backend_dev_handle = NULL;
-	backend_image_spec = NULL;
+	backend_dev_handle = (uintptr_t)NULL;
+	backend_image_spec = (uintptr_t)NULL;
 
 	return IO_SUCCESS;
 }
 
 
 /* Open a file for access from package. */
-static int fip_file_open(io_dev_info_t *dev_info, const void *spec,
+static int fip_file_open(io_dev_info_t *dev_info, const uintptr_t spec,
 			 io_entity_t *entity)
 {
 	int result = IO_FAIL;
-	io_handle backend_handle;
+	uintptr_t backend_handle;
 	uuid_t file_uuid;
 	const io_file_spec_t *file_spec = (io_file_spec_t *)spec;
 	size_t bytes_read;
@@ -273,7 +275,8 @@ static int fip_file_open(io_dev_info_t *dev_info, const void *spec,
 
 	found_file = 0;
 	do {
-		result = io_read(backend_handle, &current_file.entry,
+		result = io_read(backend_handle,
+				 (uintptr_t)&current_file.entry,
 				 sizeof(current_file.entry),
 				 &bytes_read);
 		if (result == IO_SUCCESS) {
@@ -322,19 +325,19 @@ static int fip_file_len(io_entity_t *entity, size_t *length)
 
 
 /* Read data from a file in package */
-static int fip_file_read(io_entity_t *entity, void *buffer, size_t length,
+static int fip_file_read(io_entity_t *entity, uintptr_t buffer, size_t length,
 			  size_t *length_read)
 {
 	int result = IO_FAIL;
 	file_state_t *fp;
 	size_t file_offset;
 	size_t bytes_read;
-	io_handle backend_handle;
+	uintptr_t backend_handle;
 
 	assert(entity != NULL);
-	assert(buffer != NULL);
+	assert(buffer != (uintptr_t)NULL);
 	assert(length_read != NULL);
-	assert((void *)entity->info != NULL);
+	assert(entity->info != (uintptr_t)NULL);
 
 	/* Open the backend, attempt to access the blob image */
 	result = io_open(backend_dev_handle, backend_image_spec,
@@ -396,7 +399,7 @@ static int fip_file_close(io_entity_t *entity)
 /* Exported functions */
 
 /* Register the Firmware Image Package driver with the IO abstraction */
-int register_io_dev_fip(io_dev_connector_t **dev_con)
+int register_io_dev_fip(const io_dev_connector_t **dev_con)
 {
 	int result = IO_FAIL;
 	assert(dev_con != NULL);
diff --git a/drivers/io/io_memmap.c b/drivers/io/io_memmap.c
index a40e612..fc06fbb 100644
--- a/drivers/io/io_memmap.c
+++ b/drivers/io/io_memmap.c
@@ -42,9 +42,9 @@ typedef struct {
 	/* Use the 'in_use' flag as any value for base and file_pos could be
 	 * valid.
 	 */
-	int	in_use;
-	size_t	base;
-	size_t  file_pos;
+	int		in_use;
+	uintptr_t	base;
+	size_t		file_pos;
 } file_state_t;
 
 static file_state_t current_file = {0};
@@ -56,25 +56,25 @@ io_type_t device_type_memmap(void)
 }
 
 /* Memmap device functions */
-static int memmap_dev_open(void *spec, io_dev_info_t **dev_info);
-static int memmap_block_open(io_dev_info_t *dev_info, const void *spec,
+static int memmap_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info);
+static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec,
 			     io_entity_t *entity);
 static int memmap_block_seek(io_entity_t *entity, int mode,
 			     ssize_t offset);
-static int memmap_block_read(io_entity_t *entity, void *buffer,
+static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
 			     size_t length, size_t *length_read);
-static int memmap_block_write(io_entity_t *entity, const void *buffer,
+static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer,
 			      size_t length, size_t *length_written);
 static int memmap_block_close(io_entity_t *entity);
 static int memmap_dev_close(io_dev_info_t *dev_info);
 
 
-static struct io_dev_connector memmap_dev_connector = {
+static const io_dev_connector_t memmap_dev_connector = {
 	.dev_open = memmap_dev_open
 };
 
 
-static struct io_dev_funcs memmap_dev_funcs = {
+static const io_dev_funcs_t memmap_dev_funcs = {
 	.type = device_type_memmap,
 	.open = memmap_block_open,
 	.seek = memmap_block_seek,
@@ -87,18 +87,19 @@ static struct io_dev_funcs memmap_dev_funcs = {
 };
 
 
-static struct io_dev_info memmap_dev_info = {
+/* No state associated with this device so structure can be const */
+static const io_dev_info_t memmap_dev_info = {
 	.funcs = &memmap_dev_funcs,
 	.info = (uintptr_t)NULL
 };
 
 
 /* Open a connection to the memmap device */
-static int memmap_dev_open(void *spec __attribute__((unused)),
+static int memmap_dev_open(const uintptr_t dev_spec __attribute__((unused)),
 			   io_dev_info_t **dev_info)
 {
 	assert(dev_info != NULL);
-	*dev_info = &memmap_dev_info;
+	*dev_info = (io_dev_info_t *)&memmap_dev_info; /* cast away const */
 
 	return IO_SUCCESS;
 }
@@ -116,7 +117,7 @@ static int memmap_dev_close(io_dev_info_t *dev_info)
 
 /* Open a file on the memmap device */
 /* TODO: Can we do any sensible limit checks on requested memory */
-static int memmap_block_open(io_dev_info_t *dev_info, const void *spec,
+static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec,
 			     io_entity_t *entity)
 {
 	int result = IO_FAIL;
@@ -166,18 +167,18 @@ static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset)
 
 
 /* Read data from a file on the memmap device */
-static int memmap_block_read(io_entity_t *entity, void *buffer,
+static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
 			     size_t length, size_t *length_read)
 {
 	file_state_t *fp;
 
 	assert(entity != NULL);
-	assert(buffer != NULL);
+	assert(buffer != (uintptr_t)NULL);
 	assert(length_read != NULL);
 
 	fp = (file_state_t *)entity->info;
 
-	memcpy(buffer, (void *)(fp->base + fp->file_pos), length);
+	memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length);
 
 	*length_read = length;
 	/* advance the file 'cursor' for incremental reads */
@@ -188,18 +189,18 @@ static int memmap_block_read(io_entity_t *entity, void *buffer,
 
 
 /* Write data to a file on the memmap device */
-static int memmap_block_write(io_entity_t *entity, const void *buffer,
+static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer,
 			      size_t length, size_t *length_written)
 {
 	file_state_t *fp;
 
 	assert(entity != NULL);
-	assert(buffer != NULL);
+	assert(buffer != (uintptr_t)NULL);
 	assert(length_written != NULL);
 
 	fp = (file_state_t *)entity->info;
 
-	memcpy((void *)(fp->base + fp->file_pos), buffer, length);
+	memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length);
 
 	*length_written = length;
 
@@ -227,7 +228,7 @@ static int memmap_block_close(io_entity_t *entity)
 /* Exported functions */
 
 /* Register the memmap driver with the IO abstraction */
-int register_io_dev_memmap(io_dev_connector_t **dev_con)
+int register_io_dev_memmap(const io_dev_connector_t **dev_con)
 {
 	int result = IO_FAIL;
 	assert(dev_con != NULL);
diff --git a/drivers/io/io_semihosting.c b/drivers/io/io_semihosting.c
index a37693d..3c92c6d 100644
--- a/drivers/io/io_semihosting.c
+++ b/drivers/io/io_semihosting.c
@@ -44,23 +44,23 @@ static io_type_t device_type_sh(void)
 
 /* Semi-hosting functions, device info and handle */
 
-static int sh_dev_open(void *spec, io_dev_info_t **dev_info);
-static int sh_file_open(io_dev_info_t *dev_info, const void *spec,
+static int sh_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info);
+static int sh_file_open(io_dev_info_t *dev_info, const uintptr_t spec,
 		io_entity_t *entity);
 static int sh_file_seek(io_entity_t *entity, int mode, ssize_t offset);
 static int sh_file_len(io_entity_t *entity, size_t *length);
-static int sh_file_read(io_entity_t *entity, void *buffer, size_t length,
+static int sh_file_read(io_entity_t *entity, uintptr_t buffer, size_t length,
 		size_t *length_read);
-static int sh_file_write(io_entity_t *entity, const void *buffer,
+static int sh_file_write(io_entity_t *entity, const uintptr_t buffer,
 		size_t length, size_t *length_written);
 static int sh_file_close(io_entity_t *entity);
 
-static struct io_dev_connector sh_dev_connector = {
+static const io_dev_connector_t sh_dev_connector = {
 	.dev_open = sh_dev_open
 };
 
 
-static struct io_dev_funcs sh_dev_funcs = {
+static const io_dev_funcs_t sh_dev_funcs = {
 	.type = device_type_sh,
 	.open = sh_file_open,
 	.seek = sh_file_seek,
@@ -73,29 +73,31 @@ static struct io_dev_funcs sh_dev_funcs = {
 };
 
 
-static struct io_dev_info sh_dev_info = {
+/* No state associated with this device so structure can be const */
+static const io_dev_info_t sh_dev_info = {
 	.funcs = &sh_dev_funcs,
 	.info = (uintptr_t)NULL
 };
 
 
 /* Open a connection to the semi-hosting device */
-static int sh_dev_open(void *spec __unused, io_dev_info_t **dev_info)
+static int sh_dev_open(const uintptr_t dev_spec __unused,
+		io_dev_info_t **dev_info)
 {
 	int result = IO_SUCCESS;
 	assert(dev_info != NULL);
-	*dev_info = &sh_dev_info;
+	*dev_info = (io_dev_info_t *)&sh_dev_info; /* cast away const */
 	return result;
 }
 
 
 /* Open a file on the semi-hosting device */
 static int sh_file_open(io_dev_info_t *dev_info __attribute__((unused)),
-		const void *spec, io_entity_t *entity)
+		const uintptr_t spec, io_entity_t *entity)
 {
 	int result = IO_FAIL;
 	long sh_result = -1;
-	const io_file_spec_t *file_spec = (io_file_spec_t *)spec;
+	const io_file_spec_t *file_spec = (const io_file_spec_t *)spec;
 
 	assert(file_spec != NULL);
 	assert(entity != NULL);
@@ -151,7 +153,7 @@ static int sh_file_len(io_entity_t *entity, size_t *length)
 
 
 /* Read data from a file on the semi-hosting device */
-static int sh_file_read(io_entity_t *entity, void *buffer, size_t length,
+static int sh_file_read(io_entity_t *entity, uintptr_t buffer, size_t length,
 		size_t *length_read)
 {
 	int result = IO_FAIL;
@@ -160,7 +162,7 @@ static int sh_file_read(io_entity_t *entity, void *buffer, size_t length,
 	long file_handle;
 
 	assert(entity != NULL);
-	assert(buffer != NULL);
+	assert(buffer != (uintptr_t)NULL);
 	assert(length_read != NULL);
 
 	file_handle = (long)entity->info;
@@ -178,7 +180,7 @@ static int sh_file_read(io_entity_t *entity, void *buffer, size_t length,
 
 
 /* Write data to a file on the semi-hosting device */
-static int sh_file_write(io_entity_t *entity, const void *buffer,
+static int sh_file_write(io_entity_t *entity, const uintptr_t buffer,
 		size_t length, size_t *length_written)
 {
 	int result = IO_FAIL;
@@ -187,7 +189,7 @@ static int sh_file_write(io_entity_t *entity, const void *buffer,
 	size_t bytes = length;
 
 	assert(entity != NULL);
-	assert(buffer != NULL);
+	assert(buffer != (uintptr_t)NULL);
 	assert(length_written != NULL);
 
 	file_handle = (long)entity->info;
@@ -226,7 +228,7 @@ static int sh_file_close(io_entity_t *entity)
 /* Exported functions */
 
 /* Register the semi-hosting driver with the IO abstraction */
-int register_io_dev_sh(io_dev_connector_t **dev_con)
+int register_io_dev_sh(const io_dev_connector_t **dev_con)
 {
 	int result = IO_FAIL;
 	assert(dev_con != NULL);