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

1 files changed, 21 insertions, 20 deletions

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);